2 * sgen-gc.c: Simple generational GC.
5 * Paolo Molaro (lupus@ximian.com)
6 * Rodrigo Kumpera (kumpera@gmail.com)
8 * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
9 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
11 * Thread start/stop adapted from Boehm's GC:
12 * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
13 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
14 * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
15 * Copyright (c) 2000-2004 by Hewlett-Packard Company. All rights reserved.
17 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
18 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
20 * Permission is hereby granted to use or copy this program
21 * for any purpose, provided the above notices are retained on all copies.
22 * Permission to modify the code and to distribute modified code is granted,
23 * provided the above notices are retained, and a notice that the code was
24 * modified is included with the above copyright notice.
27 * Copyright 2001-2003 Ximian, Inc
28 * Copyright 2003-2010 Novell, Inc.
29 * Copyright 2011 Xamarin, Inc.
31 * Permission is hereby granted, free of charge, to any person obtaining
32 * a copy of this software and associated documentation files (the
33 * "Software"), to deal in the Software without restriction, including
34 * without limitation the rights to use, copy, modify, merge, publish,
35 * distribute, sublicense, and/or sell copies of the Software, and to
36 * permit persons to whom the Software is furnished to do so, subject to
37 * the following conditions:
39 * The above copyright notice and this permission notice shall be
40 * included in all copies or substantial portions of the Software.
42 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
43 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
44 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
45 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
46 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
47 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
48 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
51 * Important: allocation provides always zeroed memory, having to do
52 * a memset after allocation is deadly for performance.
53 * Memory usage at startup is currently as follows:
55 * 64 KB internal space
57 * We should provide a small memory config with half the sizes
59 * We currently try to make as few mono assumptions as possible:
60 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
62 * 2) gc descriptor is the second word in the vtable (first word in the class)
63 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
64 * 4) there is a function to get an object's size and the number of
65 * elements in an array.
66 * 5) we know the special way bounds are allocated for complex arrays
67 * 6) we know about proxies and how to treat them when domains are unloaded
69 * Always try to keep stack usage to a minimum: no recursive behaviour
70 * and no large stack allocs.
72 * General description.
73 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
74 * When the nursery is full we start a nursery collection: this is performed with a
76 * When the old generation is full we start a copying GC of the old generation as well:
77 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
78 * in the future. Maybe we'll even do both during the same collection like IMMIX.
80 * The things that complicate this description are:
81 * *) pinned objects: we can't move them so we need to keep track of them
82 * *) no precise info of the thread stacks and registers: we need to be able to
83 * quickly find the objects that may be referenced conservatively and pin them
84 * (this makes the first issues more important)
85 * *) large objects are too expensive to be dealt with using copying GC: we handle them
86 * with mark/sweep during major collections
87 * *) some objects need to not move even if they are small (interned strings, Type handles):
88 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
89 * PinnedChunks regions
95 *) we could have a function pointer in MonoClass to implement
96 customized write barriers for value types
98 *) investigate the stuff needed to advance a thread to a GC-safe
99 point (single-stepping, read from unmapped memory etc) and implement it.
100 This would enable us to inline allocations and write barriers, for example,
101 or at least parts of them, like the write barrier checks.
102 We may need this also for handling precise info on stacks, even simple things
103 as having uninitialized data on the stack and having to wait for the prolog
104 to zero it. Not an issue for the last frame that we scan conservatively.
105 We could always not trust the value in the slots anyway.
107 *) modify the jit to save info about references in stack locations:
108 this can be done just for locals as a start, so that at least
109 part of the stack is handled precisely.
111 *) test/fix endianess issues
113 *) Implement a card table as the write barrier instead of remembered
114 sets? Card tables are not easy to implement with our current
115 memory layout. We have several different kinds of major heap
116 objects: Small objects in regular blocks, small objects in pinned
117 chunks and LOS objects. If we just have a pointer we have no way
118 to tell which kind of object it points into, therefore we cannot
119 know where its card table is. The least we have to do to make
120 this happen is to get rid of write barriers for indirect stores.
123 *) Get rid of write barriers for indirect stores. We can do this by
124 telling the GC to wbarrier-register an object once we do an ldloca
125 or ldelema on it, and to unregister it once it's not used anymore
126 (it can only travel downwards on the stack). The problem with
127 unregistering is that it needs to happen eventually no matter
128 what, even if exceptions are thrown, the thread aborts, etc.
129 Rodrigo suggested that we could do only the registering part and
130 let the collector find out (pessimistically) when it's safe to
131 unregister, namely when the stack pointer of the thread that
132 registered the object is higher than it was when the registering
133 happened. This might make for a good first implementation to get
134 some data on performance.
136 *) Some sort of blacklist support? Blacklists is a concept from the
137 Boehm GC: if during a conservative scan we find pointers to an
138 area which we might use as heap, we mark that area as unusable, so
139 pointer retention by random pinning pointers is reduced.
141 *) experiment with max small object size (very small right now - 2kb,
142 because it's tied to the max freelist size)
144 *) add an option to mmap the whole heap in one chunk: it makes for many
145 simplifications in the checks (put the nursery at the top and just use a single
146 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
147 not flexible (too much of the address space may be used by default or we can't
148 increase the heap as needed) and we'd need a race-free mechanism to return memory
149 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
150 was written to, munmap is needed, but the following mmap may not find the same segment
153 *) memzero the major fragments after restarting the world and optionally a smaller
156 *) investigate having fragment zeroing threads
158 *) separate locks for finalization and other minor stuff to reduce
161 *) try a different copying order to improve memory locality
163 *) a thread abort after a store but before the write barrier will
164 prevent the write barrier from executing
166 *) specialized dynamically generated markers/copiers
168 *) Dynamically adjust TLAB size to the number of threads. If we have
169 too many threads that do allocation, we might need smaller TLABs,
170 and we might get better performance with larger TLABs if we only
171 have a handful of threads. We could sum up the space left in all
172 assigned TLABs and if that's more than some percentage of the
173 nursery size, reduce the TLAB size.
175 *) Explore placing unreachable objects on unused nursery memory.
176 Instead of memset'ng a region to zero, place an int[] covering it.
177 A good place to start is add_nursery_frag. The tricky thing here is
178 placing those objects atomically outside of a collection.
180 *) Allocation should use asymmetric Dekker synchronization:
181 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
182 This should help weak consistency archs.
189 #define _XOPEN_SOURCE
190 #define _DARWIN_C_SOURCE
196 #ifdef HAVE_PTHREAD_H
199 #ifdef HAVE_SEMAPHORE_H
200 #include <semaphore.h>
208 #include "metadata/sgen-gc.h"
209 #include "metadata/metadata-internals.h"
210 #include "metadata/class-internals.h"
211 #include "metadata/gc-internal.h"
212 #include "metadata/object-internals.h"
213 #include "metadata/threads.h"
214 #include "metadata/sgen-cardtable.h"
215 #include "metadata/sgen-ssb.h"
216 #include "metadata/sgen-protocol.h"
217 #include "metadata/sgen-archdep.h"
218 #include "metadata/sgen-bridge.h"
219 #include "metadata/sgen-memory-governor.h"
220 #include "metadata/sgen-hash-table.h"
221 #include "metadata/mono-gc.h"
222 #include "metadata/method-builder.h"
223 #include "metadata/profiler-private.h"
224 #include "metadata/monitor.h"
225 #include "metadata/threadpool-internals.h"
226 #include "metadata/mempool-internals.h"
227 #include "metadata/marshal.h"
228 #include "metadata/runtime.h"
229 #include "metadata/sgen-cardtable.h"
230 #include "metadata/sgen-pinning.h"
231 #include "metadata/sgen-workers.h"
232 #include "utils/mono-mmap.h"
233 #include "utils/mono-time.h"
234 #include "utils/mono-semaphore.h"
235 #include "utils/mono-counters.h"
236 #include "utils/mono-proclib.h"
237 #include "utils/mono-memory-model.h"
238 #include "utils/mono-logger-internal.h"
239 #include "utils/dtrace.h"
241 #include <mono/utils/mono-logger-internal.h>
242 #include <mono/utils/memcheck.h>
244 #if defined(__MACH__)
245 #include "utils/mach-support.h"
248 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
252 #include "mono/cil/opcode.def"
258 #undef pthread_create
260 #undef pthread_detach
263 * ######################################################################
264 * ######## Types and constants used by the GC.
265 * ######################################################################
268 /* 0 means not initialized, 1 is initialized, -1 means in progress */
269 static int gc_initialized = 0;
270 /* If set, check if we need to do something every X allocations */
271 gboolean has_per_allocation_action;
272 /* If set, do a heap check every X allocation */
273 guint32 verify_before_allocs = 0;
274 /* If set, do a minor collection before every X allocation */
275 guint32 collect_before_allocs = 0;
276 /* If set, do a whole heap check before each collection */
277 static gboolean whole_heap_check_before_collection = FALSE;
278 /* If set, do a heap consistency check before each minor collection */
279 static gboolean consistency_check_at_minor_collection = FALSE;
280 /* If set, check that there are no references to the domain left at domain unload */
281 static gboolean xdomain_checks = FALSE;
282 /* If not null, dump the heap after each collection into this file */
283 static FILE *heap_dump_file = NULL;
284 /* If set, mark stacks conservatively, even if precise marking is possible */
285 static gboolean conservative_stack_mark = FALSE;
286 /* If set, do a plausibility check on the scan_starts before and after
288 static gboolean do_scan_starts_check = FALSE;
289 static gboolean nursery_collection_is_parallel = FALSE;
290 static gboolean disable_minor_collections = FALSE;
291 static gboolean disable_major_collections = FALSE;
292 gboolean do_pin_stats = FALSE;
293 static gboolean do_verify_nursery = FALSE;
294 static gboolean do_dump_nursery_content = FALSE;
296 #ifdef HEAVY_STATISTICS
297 long long stat_objects_alloced_degraded = 0;
298 long long stat_bytes_alloced_degraded = 0;
300 long long stat_copy_object_called_nursery = 0;
301 long long stat_objects_copied_nursery = 0;
302 long long stat_copy_object_called_major = 0;
303 long long stat_objects_copied_major = 0;
305 long long stat_scan_object_called_nursery = 0;
306 long long stat_scan_object_called_major = 0;
308 long long stat_slots_allocated_in_vain;
310 long long stat_nursery_copy_object_failed_from_space = 0;
311 long long stat_nursery_copy_object_failed_forwarded = 0;
312 long long stat_nursery_copy_object_failed_pinned = 0;
313 long long stat_nursery_copy_object_failed_to_space = 0;
315 static int stat_wbarrier_set_field = 0;
316 static int stat_wbarrier_set_arrayref = 0;
317 static int stat_wbarrier_arrayref_copy = 0;
318 static int stat_wbarrier_generic_store = 0;
319 static int stat_wbarrier_set_root = 0;
320 static int stat_wbarrier_value_copy = 0;
321 static int stat_wbarrier_object_copy = 0;
324 int stat_minor_gcs = 0;
325 int stat_major_gcs = 0;
327 static long long stat_pinned_objects = 0;
329 static long long time_minor_pre_collection_fragment_clear = 0;
330 static long long time_minor_pinning = 0;
331 static long long time_minor_scan_remsets = 0;
332 static long long time_minor_scan_pinned = 0;
333 static long long time_minor_scan_registered_roots = 0;
334 static long long time_minor_scan_thread_data = 0;
335 static long long time_minor_finish_gray_stack = 0;
336 static long long time_minor_fragment_creation = 0;
338 static long long time_major_pre_collection_fragment_clear = 0;
339 static long long time_major_pinning = 0;
340 static long long time_major_scan_pinned = 0;
341 static long long time_major_scan_registered_roots = 0;
342 static long long time_major_scan_thread_data = 0;
343 static long long time_major_scan_alloc_pinned = 0;
344 static long long time_major_scan_finalized = 0;
345 static long long time_major_scan_big_objects = 0;
346 static long long time_major_finish_gray_stack = 0;
347 static long long time_major_free_bigobjs = 0;
348 static long long time_major_los_sweep = 0;
349 static long long time_major_sweep = 0;
350 static long long time_major_fragment_creation = 0;
352 int gc_debug_level = 0;
357 mono_gc_flush_info (void)
359 fflush (gc_debug_file);
363 #define TV_DECLARE SGEN_TV_DECLARE
364 #define TV_GETTIME SGEN_TV_GETTIME
365 #define TV_ELAPSED SGEN_TV_ELAPSED
366 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
368 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
370 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
372 /* the runtime can register areas of memory as roots: we keep two lists of roots,
373 * a pinned root set for conservatively scanned roots and a normal one for
374 * precisely scanned roots (currently implemented as a single list).
376 typedef struct _RootRecord RootRecord;
382 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
383 #define object_is_pinned SGEN_OBJECT_IS_PINNED
384 #define pin_object SGEN_PIN_OBJECT
385 #define unpin_object SGEN_UNPIN_OBJECT
387 #define ptr_in_nursery sgen_ptr_in_nursery
389 #define LOAD_VTABLE SGEN_LOAD_VTABLE
392 safe_name (void* obj)
394 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
395 return vt->klass->name;
398 #define safe_object_get_size sgen_safe_object_get_size
401 sgen_safe_name (void* obj)
403 return safe_name (obj);
407 * ######################################################################
408 * ######## Global data.
409 * ######################################################################
411 LOCK_DECLARE (gc_mutex);
412 static int gc_disabled = 0;
414 static gboolean use_cardtable;
416 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
418 static mword pagesize = 4096;
419 int degraded_mode = 0;
421 static mword bytes_pinned_from_failed_allocation = 0;
423 GCMemSection *nursery_section = NULL;
424 static mword lowest_heap_address = ~(mword)0;
425 static mword highest_heap_address = 0;
427 static LOCK_DECLARE (interruption_mutex);
428 static LOCK_DECLARE (pin_queue_mutex);
430 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
431 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
433 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
434 struct _FinalizeReadyEntry {
435 FinalizeReadyEntry *next;
439 typedef struct _EphemeronLinkNode EphemeronLinkNode;
441 struct _EphemeronLinkNode {
442 EphemeronLinkNode *next;
451 int current_collection_generation = -1;
454 * The link pointer is hidden by negating each bit. We use the lowest
455 * bit of the link (before negation) to store whether it needs
456 * resurrection tracking.
458 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
459 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
461 /* objects that are ready to be finalized */
462 static FinalizeReadyEntry *fin_ready_list = NULL;
463 static FinalizeReadyEntry *critical_fin_list = NULL;
465 static EphemeronLinkNode *ephemeron_list;
467 static int num_ready_finalizers = 0;
468 static int no_finalize = 0;
471 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
472 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
473 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
477 /* registered roots: the key to the hash is the root start address */
479 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
481 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
482 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
483 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
484 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
486 static mword roots_size = 0; /* amount of memory in the root set */
488 #define GC_ROOT_NUM 32
491 void *objects [GC_ROOT_NUM];
492 int root_types [GC_ROOT_NUM];
493 uintptr_t extra_info [GC_ROOT_NUM];
497 notify_gc_roots (GCRootReport *report)
501 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
506 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
508 if (report->count == GC_ROOT_NUM)
509 notify_gc_roots (report);
510 report->objects [report->count] = object;
511 report->root_types [report->count] = rtype;
512 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
515 MonoNativeTlsKey thread_info_key;
517 #ifdef HAVE_KW_THREAD
518 __thread SgenThreadInfo *thread_info;
519 __thread gpointer *store_remset_buffer;
520 __thread long store_remset_buffer_index;
521 __thread char *stack_end;
522 __thread long *store_remset_buffer_index_addr;
525 /* The size of a TLAB */
526 /* The bigger the value, the less often we have to go to the slow path to allocate a new
527 * one, but the more space is wasted by threads not allocating much memory.
529 * FIXME: Make this self-tuning for each thread.
531 guint32 tlab_size = (1024 * 4);
533 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
535 /* Functions supplied by the runtime to be called by the GC */
536 static MonoGCCallbacks gc_callbacks;
538 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
539 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
541 #define ALIGN_UP SGEN_ALIGN_UP
543 #define MOVED_OBJECTS_NUM 64
544 static void *moved_objects [MOVED_OBJECTS_NUM];
545 static int moved_objects_idx = 0;
547 /* Vtable of the objects used to fill out nursery fragments before a collection */
548 static MonoVTable *array_fill_vtable;
550 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
551 MonoNativeThreadId main_gc_thread = NULL;
554 /*Object was pinned during the current collection*/
555 static mword objects_pinned;
558 * ######################################################################
559 * ######## Macros and function declarations.
560 * ######################################################################
564 align_pointer (void *ptr)
566 mword p = (mword)ptr;
567 p += sizeof (gpointer) - 1;
568 p &= ~ (sizeof (gpointer) - 1);
572 typedef SgenGrayQueue GrayQueue;
574 /* forward declarations */
575 static int stop_world (int generation);
576 static int restart_world (int generation, GGTimingInfo *timing);
577 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
578 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
579 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
580 static void report_finalizer_roots (void);
581 static void report_registered_roots (void);
582 static void find_pinning_ref_from_thread (char *obj, size_t size);
583 static void update_current_thread_stack (void *start);
584 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
585 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
586 static void process_fin_stage_entries (void);
587 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
588 static void null_links_for_domain (MonoDomain *domain, int generation);
589 static void remove_finalizers_for_domain (MonoDomain *domain, int generation);
590 static void process_dislink_stage_entries (void);
592 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
593 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
594 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
596 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
597 static gboolean mono_gc_is_critical_method (MonoMethod *method);
599 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
602 static void init_stats (void);
604 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
605 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
606 static void null_ephemerons_for_domain (MonoDomain *domain);
608 SgenObjectOperations current_object_ops;
609 SgenMajorCollector major_collector;
610 SgenMinorCollector sgen_minor_collector;
611 static GrayQueue gray_queue;
613 static SgenRemeberedSet remset;
616 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (sgen_collection_is_parallel () ? sgen_workers_get_distribute_gray_queue () : &gray_queue)
618 static SgenGrayQueue*
619 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
621 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
625 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
627 MonoObject *o = (MonoObject*)(obj);
628 MonoObject *ref = (MonoObject*)*(ptr);
629 int offset = (char*)(ptr) - (char*)o;
631 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
633 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
635 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
636 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
638 /* Thread.cached_culture_info */
639 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
640 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
641 !strcmp(o->vtable->klass->name_space, "System") &&
642 !strcmp(o->vtable->klass->name, "Object[]"))
645 * at System.IO.MemoryStream.InternalConstructor (byte[],int,int,bool,bool) [0x0004d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:121
646 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
647 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
648 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
649 * at System.Runtime.Remoting.Messaging.MethodCall..ctor (System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/MethodCall.cs:87
650 * at System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) [0x00018] in /home/schani/Work/novell/trunk/mcs/class/corlib/System/AppDomain.cs:1213
651 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
652 * at System.Runtime.Remoting.Channels.CrossAppDomainSink.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00008] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Channels/CrossAppDomainChannel.cs:198
653 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
655 if (!strcmp (ref->vtable->klass->name_space, "System") &&
656 !strcmp (ref->vtable->klass->name, "Byte[]") &&
657 !strcmp (o->vtable->klass->name_space, "System.IO") &&
658 !strcmp (o->vtable->klass->name, "MemoryStream"))
660 /* append_job() in threadpool.c */
661 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
662 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
663 !strcmp (o->vtable->klass->name_space, "System") &&
664 !strcmp (o->vtable->klass->name, "Object[]") &&
665 mono_thread_pool_is_queue_array ((MonoArray*) o))
671 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
673 MonoObject *o = (MonoObject*)(obj);
674 MonoObject *ref = (MonoObject*)*(ptr);
675 int offset = (char*)(ptr) - (char*)o;
677 MonoClassField *field;
680 if (!ref || ref->vtable->domain == domain)
682 if (is_xdomain_ref_allowed (ptr, obj, domain))
686 for (class = o->vtable->klass; class; class = class->parent) {
689 for (i = 0; i < class->field.count; ++i) {
690 if (class->fields[i].offset == offset) {
691 field = &class->fields[i];
699 if (ref->vtable->klass == mono_defaults.string_class)
700 str = mono_string_to_utf8 ((MonoString*)ref);
703 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
704 o, o->vtable->klass->name_space, o->vtable->klass->name,
705 offset, field ? field->name : "",
706 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
707 mono_gc_scan_for_specific_ref (o, TRUE);
713 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
716 scan_object_for_xdomain_refs (char *start, mword size, void *data)
718 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
720 #include "sgen-scan-object.h"
723 static gboolean scan_object_for_specific_ref_precise = TRUE;
726 #define HANDLE_PTR(ptr,obj) do { \
727 if ((MonoObject*)*(ptr) == key) { \
728 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
729 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
734 scan_object_for_specific_ref (char *start, MonoObject *key)
738 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
741 if (scan_object_for_specific_ref_precise) {
742 #include "sgen-scan-object.h"
744 mword *words = (mword*)start;
745 size_t size = safe_object_get_size ((MonoObject*)start);
747 for (i = 0; i < size / sizeof (mword); ++i) {
748 if (words [i] == (mword)key) {
749 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
750 key, start, safe_name (start), i * sizeof (mword));
757 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
759 while (start < end) {
763 if (!*(void**)start) {
764 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
769 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
775 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
777 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
778 callback (obj, size, data);
785 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
787 scan_object_for_specific_ref (obj, key);
791 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
795 g_print ("found ref to %p in root record %p\n", key, root);
798 static MonoObject *check_key = NULL;
799 static RootRecord *check_root = NULL;
802 check_root_obj_specific_ref_from_marker (void **obj)
804 check_root_obj_specific_ref (check_root, check_key, *obj);
808 scan_roots_for_specific_ref (MonoObject *key, int root_type)
814 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
815 mword desc = root->root_desc;
819 switch (desc & ROOT_DESC_TYPE_MASK) {
820 case ROOT_DESC_BITMAP:
821 desc >>= ROOT_DESC_TYPE_SHIFT;
824 check_root_obj_specific_ref (root, key, *start_root);
829 case ROOT_DESC_COMPLEX: {
830 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
831 int bwords = (*bitmap_data) - 1;
832 void **start_run = start_root;
834 while (bwords-- > 0) {
835 gsize bmap = *bitmap_data++;
836 void **objptr = start_run;
839 check_root_obj_specific_ref (root, key, *objptr);
843 start_run += GC_BITS_PER_WORD;
847 case ROOT_DESC_USER: {
848 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
849 marker (start_root, check_root_obj_specific_ref_from_marker);
852 case ROOT_DESC_RUN_LEN:
853 g_assert_not_reached ();
855 g_assert_not_reached ();
857 } SGEN_HASH_TABLE_FOREACH_END;
864 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
869 scan_object_for_specific_ref_precise = precise;
871 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
872 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
874 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
876 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
878 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
879 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
881 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
882 while (ptr < (void**)root->end_root) {
883 check_root_obj_specific_ref (root, *ptr, key);
886 } SGEN_HASH_TABLE_FOREACH_END;
890 need_remove_object_for_domain (char *start, MonoDomain *domain)
892 if (mono_object_domain (start) == domain) {
893 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
894 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
901 process_object_for_domain_clearing (char *start, MonoDomain *domain)
903 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
904 if (vt->klass == mono_defaults.internal_thread_class)
905 g_assert (mono_object_domain (start) == mono_get_root_domain ());
906 /* The object could be a proxy for an object in the domain
908 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
909 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
911 /* The server could already have been zeroed out, so
912 we need to check for that, too. */
913 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
914 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
916 ((MonoRealProxy*)start)->unwrapped_server = NULL;
921 static MonoDomain *check_domain = NULL;
924 check_obj_not_in_domain (void **o)
926 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
930 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
934 check_domain = domain;
935 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
936 mword desc = root->root_desc;
938 /* The MonoDomain struct is allowed to hold
939 references to objects in its own domain. */
940 if (start_root == (void**)domain)
943 switch (desc & ROOT_DESC_TYPE_MASK) {
944 case ROOT_DESC_BITMAP:
945 desc >>= ROOT_DESC_TYPE_SHIFT;
947 if ((desc & 1) && *start_root)
948 check_obj_not_in_domain (*start_root);
953 case ROOT_DESC_COMPLEX: {
954 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
955 int bwords = (*bitmap_data) - 1;
956 void **start_run = start_root;
958 while (bwords-- > 0) {
959 gsize bmap = *bitmap_data++;
960 void **objptr = start_run;
962 if ((bmap & 1) && *objptr)
963 check_obj_not_in_domain (*objptr);
967 start_run += GC_BITS_PER_WORD;
971 case ROOT_DESC_USER: {
972 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
973 marker (start_root, check_obj_not_in_domain);
976 case ROOT_DESC_RUN_LEN:
977 g_assert_not_reached ();
979 g_assert_not_reached ();
981 } SGEN_HASH_TABLE_FOREACH_END;
987 check_for_xdomain_refs (void)
991 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
992 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
994 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
996 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
997 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1001 clear_domain_process_object (char *obj, MonoDomain *domain)
1005 process_object_for_domain_clearing (obj, domain);
1006 remove = need_remove_object_for_domain (obj, domain);
1008 if (remove && ((MonoObject*)obj)->synchronisation) {
1009 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1011 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1018 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1020 if (clear_domain_process_object (obj, domain))
1021 memset (obj, 0, size);
1025 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1027 clear_domain_process_object (obj, domain);
1031 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1033 if (need_remove_object_for_domain (obj, domain))
1034 major_collector.free_non_pinned_object (obj, size);
1038 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1040 if (need_remove_object_for_domain (obj, domain))
1041 major_collector.free_pinned_object (obj, size);
1045 * When appdomains are unloaded we can easily remove objects that have finalizers,
1046 * but all the others could still be present in random places on the heap.
1047 * We need a sweep to get rid of them even though it's going to be costly
1049 * The reason we need to remove them is because we access the vtable and class
1050 * structures to know the object size and the reference bitmap: once the domain is
1051 * unloaded the point to random memory.
1054 mono_gc_clear_domain (MonoDomain * domain)
1056 LOSObject *bigobj, *prev;
1061 process_fin_stage_entries ();
1062 process_dislink_stage_entries ();
1064 sgen_clear_nursery_fragments ();
1066 if (xdomain_checks && domain != mono_get_root_domain ()) {
1067 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1068 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1069 check_for_xdomain_refs ();
1072 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1073 to memory returned to the OS.*/
1074 null_ephemerons_for_domain (domain);
1076 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1077 null_links_for_domain (domain, i);
1079 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1080 remove_finalizers_for_domain (domain, i);
1082 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1083 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1085 /* We need two passes over major and large objects because
1086 freeing such objects might give their memory back to the OS
1087 (in the case of large objects) or obliterate its vtable
1088 (pinned objects with major-copying or pinned and non-pinned
1089 objects with major-mark&sweep), but we might need to
1090 dereference a pointer from an object to another object if
1091 the first object is a proxy. */
1092 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1093 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1094 clear_domain_process_object (bigobj->data, domain);
1097 for (bigobj = los_object_list; bigobj;) {
1098 if (need_remove_object_for_domain (bigobj->data, domain)) {
1099 LOSObject *to_free = bigobj;
1101 prev->next = bigobj->next;
1103 los_object_list = bigobj->next;
1104 bigobj = bigobj->next;
1105 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
1107 sgen_los_free_object (to_free);
1111 bigobj = bigobj->next;
1113 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1114 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1116 if (G_UNLIKELY (do_pin_stats)) {
1117 if (domain == mono_get_root_domain ())
1118 sgen_pin_stats_print_class_stats ();
1125 * sgen_add_to_global_remset:
1127 * The global remset contains locations which point into newspace after
1128 * a minor collection. This can happen if the objects they point to are pinned.
1130 * LOCKING: If called from a parallel collector, the global remset
1131 * lock must be held. For serial collectors that is not necessary.
1134 sgen_add_to_global_remset (gpointer ptr)
1136 remset.record_pointer (ptr);
1140 * sgen_drain_gray_stack:
1142 * Scan objects in the gray stack until the stack is empty. This should be called
1143 * frequently after each object is copied, to achieve better locality and cache
1147 sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1150 ScanObjectFunc scan_func = current_object_ops.scan_object;
1152 if (max_objs == -1) {
1154 GRAY_OBJECT_DEQUEUE (queue, obj);
1157 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1158 scan_func (obj, queue);
1164 for (i = 0; i != max_objs; ++i) {
1165 GRAY_OBJECT_DEQUEUE (queue, obj);
1168 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1169 scan_func (obj, queue);
1171 } while (max_objs < 0);
1177 * Addresses from start to end are already sorted. This function finds
1178 * the object header for each address and pins the object. The
1179 * addresses must be inside the passed section. The (start of the)
1180 * address array is overwritten with the addresses of the actually
1181 * pinned objects. Return the number of pinned objects.
1184 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue)
1189 void *last_obj = NULL;
1190 size_t last_obj_size = 0;
1193 void **definitely_pinned = start;
1195 sgen_nursery_allocator_prepare_for_pinning ();
1197 while (start < end) {
1199 /* the range check should be reduntant */
1200 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1201 DEBUG (5, fprintf (gc_debug_file, "Considering pinning addr %p\n", addr));
1202 /* multiple pointers to the same object */
1203 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1207 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1208 g_assert (idx < section->num_scan_start);
1209 search_start = (void*)section->scan_starts [idx];
1210 if (!search_start || search_start > addr) {
1213 search_start = section->scan_starts [idx];
1214 if (search_start && search_start <= addr)
1217 if (!search_start || search_start > addr)
1218 search_start = start_nursery;
1220 if (search_start < last_obj)
1221 search_start = (char*)last_obj + last_obj_size;
1222 /* now addr should be in an object a short distance from search_start
1223 * Note that search_start must point to zeroed mem or point to an object.
1227 if (!*(void**)search_start) {
1228 /* Consistency check */
1230 for (frag = nursery_fragments; frag; frag = frag->next) {
1231 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1232 g_assert_not_reached ();
1236 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1239 last_obj = search_start;
1240 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1242 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1243 /* Marks the beginning of a nursery fragment, skip */
1245 DEBUG (8, fprintf (gc_debug_file, "Pinned try match %p (%s), size %zd\n", last_obj, safe_name (last_obj), last_obj_size));
1246 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1247 DEBUG (4, fprintf (gc_debug_file, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count));
1248 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1249 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1250 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1251 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1252 MONO_GC_OBJ_PINNED ((mword)search_start, sgen_safe_object_get_size (search_start), vt->klass->name_space, vt->klass->name, gen);
1254 pin_object (search_start);
1255 GRAY_OBJECT_ENQUEUE (queue, search_start);
1256 if (G_UNLIKELY (do_pin_stats))
1257 sgen_pin_stats_register_object (search_start, last_obj_size);
1258 definitely_pinned [count] = search_start;
1263 /* skip to the next object */
1264 search_start = (void*)((char*)search_start + last_obj_size);
1265 } while (search_start <= addr);
1266 /* we either pinned the correct object or we ignored the addr because
1267 * it points to unused zeroed memory.
1273 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1274 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1275 GCRootReport report;
1277 for (idx = 0; idx < count; ++idx)
1278 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1279 notify_gc_roots (&report);
1281 stat_pinned_objects += count;
1286 sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue)
1288 int num_entries = section->pin_queue_num_entries;
1290 void **start = section->pin_queue_start;
1292 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1293 section->data, section->next_data, queue);
1294 section->pin_queue_num_entries = reduced_to;
1296 section->pin_queue_start = NULL;
1302 sgen_pin_object (void *object, GrayQueue *queue)
1304 if (sgen_collection_is_parallel ()) {
1306 /*object arrives pinned*/
1307 sgen_pin_stage_ptr (object);
1311 SGEN_PIN_OBJECT (object);
1312 sgen_pin_stage_ptr (object);
1314 if (G_UNLIKELY (do_pin_stats))
1315 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1317 GRAY_OBJECT_ENQUEUE (queue, object);
1318 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1319 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1320 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1321 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1322 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1327 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1331 gboolean major_pinned = FALSE;
1333 if (sgen_ptr_in_nursery (obj)) {
1334 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1335 sgen_pin_object (obj, queue);
1339 major_collector.pin_major_object (obj, queue);
1340 major_pinned = TRUE;
1343 vtable_word = *(mword*)obj;
1344 /*someone else forwarded it, update the pointer and bail out*/
1345 if (vtable_word & SGEN_FORWARDED_BIT) {
1346 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1350 /*someone pinned it, nothing to do.*/
1351 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1356 /* Sort the addresses in array in increasing order.
1357 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1360 sgen_sort_addresses (void **array, int size)
1365 for (i = 1; i < size; ++i) {
1368 int parent = (child - 1) / 2;
1370 if (array [parent] >= array [child])
1373 tmp = array [parent];
1374 array [parent] = array [child];
1375 array [child] = tmp;
1381 for (i = size - 1; i > 0; --i) {
1384 array [i] = array [0];
1390 while (root * 2 + 1 <= end) {
1391 int child = root * 2 + 1;
1393 if (child < end && array [child] < array [child + 1])
1395 if (array [root] >= array [child])
1399 array [root] = array [child];
1400 array [child] = tmp;
1408 * Scan the memory between start and end and queue values which could be pointers
1409 * to the area between start_nursery and end_nursery for later consideration.
1410 * Typically used for thread stacks.
1413 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1416 while (start < end) {
1417 if (*start >= start_nursery && *start < end_nursery) {
1419 * *start can point to the middle of an object
1420 * note: should we handle pointing at the end of an object?
1421 * pinning in C# code disallows pointing at the end of an object
1422 * but there is some small chance that an optimizing C compiler
1423 * may keep the only reference to an object by pointing
1424 * at the end of it. We ignore this small chance for now.
1425 * Pointers to the end of an object are indistinguishable
1426 * from pointers to the start of the next object in memory
1427 * so if we allow that we'd need to pin two objects...
1428 * We queue the pointer in an array, the
1429 * array will then be sorted and uniqued. This way
1430 * we can coalesce several pinning pointers and it should
1431 * be faster since we'd do a memory scan with increasing
1432 * addresses. Note: we can align the address to the allocation
1433 * alignment, so the unique process is more effective.
1435 mword addr = (mword)*start;
1436 addr &= ~(ALLOC_ALIGN - 1);
1437 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1438 sgen_pin_stage_ptr ((void*)addr);
1439 if (G_UNLIKELY (do_pin_stats)) {
1440 if (ptr_in_nursery ((void*)addr))
1441 sgen_pin_stats_register_address ((char*)addr, pin_type);
1443 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1448 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1452 * Debugging function: find in the conservative roots where @obj is being pinned.
1454 static G_GNUC_UNUSED void
1455 find_pinning_reference (char *obj, size_t size)
1459 char *endobj = obj + size;
1461 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1462 /* if desc is non-null it has precise info */
1463 if (!root->root_desc) {
1464 while (start < (char**)root->end_root) {
1465 if (*start >= obj && *start < endobj) {
1466 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1471 } SGEN_HASH_TABLE_FOREACH_END;
1473 find_pinning_ref_from_thread (obj, size);
1477 * The first thing we do in a collection is to identify pinned objects.
1478 * This function considers all the areas of memory that need to be
1479 * conservatively scanned.
1482 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1486 DEBUG (2, fprintf (gc_debug_file, "Scanning pinned roots (%d bytes, %d/%d entries)\n", (int)roots_size, roots_hash [ROOT_TYPE_NORMAL].num_entries, roots_hash [ROOT_TYPE_PINNED].num_entries));
1487 /* objects pinned from the API are inside these roots */
1488 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1489 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1490 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1491 } SGEN_HASH_TABLE_FOREACH_END;
1492 /* now deal with the thread stacks
1493 * in the future we should be able to conservatively scan only:
1494 * *) the cpu registers
1495 * *) the unmanaged stack frames
1496 * *) the _last_ managed stack frame
1497 * *) pointers slots in managed frames
1499 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1503 CopyOrMarkObjectFunc func;
1505 } UserCopyOrMarkData;
1507 static MonoNativeTlsKey user_copy_or_mark_key;
1510 init_user_copy_or_mark_key (void)
1512 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1516 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1518 mono_native_tls_set_value (user_copy_or_mark_key, data);
1522 single_arg_user_copy_or_mark (void **obj)
1524 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1526 data->func (obj, data->queue);
1530 * The memory area from start_root to end_root contains pointers to objects.
1531 * Their position is precisely described by @desc (this means that the pointer
1532 * can be either NULL or the pointer to the start of an object).
1533 * This functions copies them to to_space updates them.
1535 * This function is not thread-safe!
1538 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1540 switch (desc & ROOT_DESC_TYPE_MASK) {
1541 case ROOT_DESC_BITMAP:
1542 desc >>= ROOT_DESC_TYPE_SHIFT;
1544 if ((desc & 1) && *start_root) {
1545 copy_func (start_root, queue);
1546 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1547 sgen_drain_gray_stack (queue, -1);
1553 case ROOT_DESC_COMPLEX: {
1554 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1555 int bwords = (*bitmap_data) - 1;
1556 void **start_run = start_root;
1558 while (bwords-- > 0) {
1559 gsize bmap = *bitmap_data++;
1560 void **objptr = start_run;
1562 if ((bmap & 1) && *objptr) {
1563 copy_func (objptr, queue);
1564 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1565 sgen_drain_gray_stack (queue, -1);
1570 start_run += GC_BITS_PER_WORD;
1574 case ROOT_DESC_USER: {
1575 UserCopyOrMarkData data = { copy_func, queue };
1576 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1577 set_user_copy_or_mark_data (&data);
1578 marker (start_root, single_arg_user_copy_or_mark);
1579 set_user_copy_or_mark_data (NULL);
1582 case ROOT_DESC_RUN_LEN:
1583 g_assert_not_reached ();
1585 g_assert_not_reached ();
1590 reset_heap_boundaries (void)
1592 lowest_heap_address = ~(mword)0;
1593 highest_heap_address = 0;
1597 sgen_update_heap_boundaries (mword low, mword high)
1602 old = lowest_heap_address;
1605 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1608 old = highest_heap_address;
1611 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1615 * Allocate and setup the data structures needed to be able to allocate objects
1616 * in the nursery. The nursery is stored in nursery_section.
1619 alloc_nursery (void)
1621 GCMemSection *section;
1626 if (nursery_section)
1628 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)sgen_nursery_size));
1629 /* later we will alloc a larger area for the nursery but only activate
1630 * what we need. The rest will be used as expansion if we have too many pinned
1631 * objects in the existing nursery.
1633 /* FIXME: handle OOM */
1634 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1636 alloc_size = sgen_nursery_size;
1638 /* If there isn't enough space even for the nursery we should simply abort. */
1639 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1641 #ifdef SGEN_ALIGN_NURSERY
1642 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1644 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1646 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1647 DEBUG (4, fprintf (gc_debug_file, "Expanding nursery size (%p-%p): %lu, total: %lu\n", data, data + alloc_size, (unsigned long)sgen_nursery_size, (unsigned long)mono_gc_get_heap_size ()));
1648 section->data = section->next_data = data;
1649 section->size = alloc_size;
1650 section->end_data = data + sgen_nursery_size;
1651 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1652 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1653 section->num_scan_start = scan_starts;
1654 section->block.role = MEMORY_ROLE_GEN0;
1655 section->block.next = NULL;
1657 nursery_section = section;
1659 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1663 mono_gc_get_nursery (int *shift_bits, size_t *size)
1665 *size = sgen_nursery_size;
1666 #ifdef SGEN_ALIGN_NURSERY
1667 *shift_bits = DEFAULT_NURSERY_BITS;
1671 return sgen_get_nursery_start ();
1675 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1677 SgenThreadInfo *info = mono_thread_info_current ();
1679 /* Could be called from sgen_thread_unregister () with a NULL info */
1682 info->stopped_domain = domain;
1687 mono_gc_precise_stack_mark_enabled (void)
1689 return !conservative_stack_mark;
1693 mono_gc_get_logfile (void)
1695 return sgen_get_logfile ();
1699 report_finalizer_roots_list (FinalizeReadyEntry *list)
1701 GCRootReport report;
1702 FinalizeReadyEntry *fin;
1705 for (fin = list; fin; fin = fin->next) {
1708 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1710 notify_gc_roots (&report);
1714 report_finalizer_roots (void)
1716 report_finalizer_roots_list (fin_ready_list);
1717 report_finalizer_roots_list (critical_fin_list);
1720 static GCRootReport *root_report;
1723 single_arg_report_root (void **obj)
1726 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1730 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1732 switch (desc & ROOT_DESC_TYPE_MASK) {
1733 case ROOT_DESC_BITMAP:
1734 desc >>= ROOT_DESC_TYPE_SHIFT;
1736 if ((desc & 1) && *start_root) {
1737 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1743 case ROOT_DESC_COMPLEX: {
1744 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1745 int bwords = (*bitmap_data) - 1;
1746 void **start_run = start_root;
1748 while (bwords-- > 0) {
1749 gsize bmap = *bitmap_data++;
1750 void **objptr = start_run;
1752 if ((bmap & 1) && *objptr) {
1753 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1758 start_run += GC_BITS_PER_WORD;
1762 case ROOT_DESC_USER: {
1763 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1764 root_report = report;
1765 marker (start_root, single_arg_report_root);
1768 case ROOT_DESC_RUN_LEN:
1769 g_assert_not_reached ();
1771 g_assert_not_reached ();
1776 report_registered_roots_by_type (int root_type)
1778 GCRootReport report;
1782 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1783 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1784 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1785 } SGEN_HASH_TABLE_FOREACH_END;
1786 notify_gc_roots (&report);
1790 report_registered_roots (void)
1792 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1793 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1797 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1799 FinalizeReadyEntry *fin;
1801 for (fin = list; fin; fin = fin->next) {
1804 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
1805 copy_func (&fin->object, queue);
1810 generation_name (int generation)
1812 switch (generation) {
1813 case GENERATION_NURSERY: return "nursery";
1814 case GENERATION_OLD: return "old";
1815 default: g_assert_not_reached ();
1821 stw_bridge_process (void)
1823 sgen_bridge_processing_stw_step ();
1827 bridge_process (int generation)
1829 sgen_bridge_processing_finish (generation);
1832 SgenObjectOperations *
1833 sgen_get_current_object_ops (void){
1834 return ¤t_object_ops;
1839 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1843 int done_with_ephemerons, ephemeron_rounds = 0;
1844 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1847 * We copied all the reachable objects. Now it's the time to copy
1848 * the objects that were not referenced by the roots, but by the copied objects.
1849 * we built a stack of objects pointed to by gray_start: they are
1850 * additional roots and we may add more items as we go.
1851 * We loop until gray_start == gray_objects which means no more objects have
1852 * been added. Note this is iterative: no recursion is involved.
1853 * We need to walk the LO list as well in search of marked big objects
1854 * (use a flag since this is needed only on major collections). We need to loop
1855 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1856 * To achieve better cache locality and cache usage, we drain the gray stack
1857 * frequently, after each object is copied, and just finish the work here.
1859 sgen_drain_gray_stack (queue, -1);
1861 DEBUG (2, fprintf (gc_debug_file, "%s generation done\n", generation_name (generation)));
1864 Reset bridge data, we might have lingering data from a previous collection if this is a major
1865 collection trigged by minor overflow.
1867 We must reset the gathered bridges since their original block might be evacuated due to major
1868 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1870 sgen_bridge_reset_data ();
1873 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1874 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1875 * objects that are in fact reachable.
1877 done_with_ephemerons = 0;
1879 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1880 sgen_drain_gray_stack (queue, -1);
1882 } while (!done_with_ephemerons);
1884 sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1885 if (generation == GENERATION_OLD)
1886 sgen_scan_togglerefs (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), queue);
1888 if (sgen_need_bridge_processing ()) {
1889 collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
1890 if (generation == GENERATION_OLD)
1891 collect_bridge_objects (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1895 Make sure we drain the gray stack before processing disappearing links and finalizers.
1896 If we don't make sure it is empty we might wrongly see a live object as dead.
1898 sgen_drain_gray_stack (queue, -1);
1901 We must clear weak links that don't track resurrection before processing object ready for
1902 finalization so they can be cleared before that.
1904 null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1905 if (generation == GENERATION_OLD)
1906 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1909 /* walk the finalization queue and move also the objects that need to be
1910 * finalized: use the finalized objects as new roots so the objects they depend
1911 * on are also not reclaimed. As with the roots above, only objects in the nursery
1912 * are marked/copied.
1914 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
1915 if (generation == GENERATION_OLD)
1916 finalize_in_range (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1917 /* drain the new stack that might have been created */
1918 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
1919 sgen_drain_gray_stack (queue, -1);
1922 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1924 done_with_ephemerons = 0;
1926 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1927 sgen_drain_gray_stack (queue, -1);
1929 } while (!done_with_ephemerons);
1932 * Clear ephemeron pairs with unreachable keys.
1933 * We pass the copy func so we can figure out if an array was promoted or not.
1935 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
1938 DEBUG (2, fprintf (gc_debug_file, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron roundss\n", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds));
1941 * handle disappearing links
1942 * Note we do this after checking the finalization queue because if an object
1943 * survives (at least long enough to be finalized) we don't clear the link.
1944 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1945 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1948 g_assert (sgen_gray_object_queue_is_empty (queue));
1950 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
1951 if (generation == GENERATION_OLD)
1952 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
1953 if (sgen_gray_object_queue_is_empty (queue))
1955 sgen_drain_gray_stack (queue, -1);
1958 g_assert (sgen_gray_object_queue_is_empty (queue));
1962 sgen_check_section_scan_starts (GCMemSection *section)
1965 for (i = 0; i < section->num_scan_start; ++i) {
1966 if (section->scan_starts [i]) {
1967 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1968 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1974 check_scan_starts (void)
1976 if (!do_scan_starts_check)
1978 sgen_check_section_scan_starts (nursery_section);
1979 major_collector.check_scan_starts ();
1983 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
1987 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1988 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1989 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
1990 } SGEN_HASH_TABLE_FOREACH_END;
1994 sgen_dump_occupied (char *start, char *end, char *section_start)
1996 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2000 sgen_dump_section (GCMemSection *section, const char *type)
2002 char *start = section->data;
2003 char *end = section->data + section->size;
2004 char *occ_start = NULL;
2006 char *old_start = NULL; /* just for debugging */
2008 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2010 while (start < end) {
2014 if (!*(void**)start) {
2016 sgen_dump_occupied (occ_start, start, section->data);
2019 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2022 g_assert (start < section->next_data);
2027 vt = (GCVTable*)LOAD_VTABLE (start);
2030 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2033 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2034 start - section->data,
2035 vt->klass->name_space, vt->klass->name,
2043 sgen_dump_occupied (occ_start, start, section->data);
2045 fprintf (heap_dump_file, "</section>\n");
2049 dump_object (MonoObject *obj, gboolean dump_location)
2051 static char class_name [1024];
2053 MonoClass *class = mono_object_class (obj);
2057 * Python's XML parser is too stupid to parse angle brackets
2058 * in strings, so we just ignore them;
2061 while (class->name [i] && j < sizeof (class_name) - 1) {
2062 if (!strchr ("<>\"", class->name [i]))
2063 class_name [j++] = class->name [i];
2066 g_assert (j < sizeof (class_name));
2069 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2070 class->name_space, class_name,
2071 safe_object_get_size (obj));
2072 if (dump_location) {
2073 const char *location;
2074 if (ptr_in_nursery (obj))
2075 location = "nursery";
2076 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2080 fprintf (heap_dump_file, " location=\"%s\"", location);
2082 fprintf (heap_dump_file, "/>\n");
2086 dump_heap (const char *type, int num, const char *reason)
2091 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2093 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2094 fprintf (heap_dump_file, ">\n");
2095 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2096 sgen_dump_internal_mem_usage (heap_dump_file);
2097 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2098 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2099 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2101 fprintf (heap_dump_file, "<pinned-objects>\n");
2102 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2103 dump_object (list->obj, TRUE);
2104 fprintf (heap_dump_file, "</pinned-objects>\n");
2106 sgen_dump_section (nursery_section, "nursery");
2108 major_collector.dump_heap (heap_dump_file);
2110 fprintf (heap_dump_file, "<los>\n");
2111 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2112 dump_object ((MonoObject*)bigobj->data, FALSE);
2113 fprintf (heap_dump_file, "</los>\n");
2115 fprintf (heap_dump_file, "</collection>\n");
2119 sgen_register_moved_object (void *obj, void *destination)
2121 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2123 /* FIXME: handle this for parallel collector */
2124 g_assert (!sgen_collection_is_parallel ());
2126 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2127 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2128 moved_objects_idx = 0;
2130 moved_objects [moved_objects_idx++] = obj;
2131 moved_objects [moved_objects_idx++] = destination;
2137 static gboolean inited = FALSE;
2142 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2143 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2144 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2145 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2146 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2147 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2148 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2149 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2151 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2152 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2153 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2154 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2155 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2156 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2157 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2158 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2159 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2160 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2161 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2162 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2163 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2165 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2167 #ifdef HEAVY_STATISTICS
2168 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2169 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2170 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2171 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2172 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2173 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2174 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2176 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2177 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2179 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2180 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2181 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2182 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2184 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2185 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2187 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2189 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2190 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2191 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2192 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2194 sgen_nursery_allocator_init_heavy_stats ();
2195 sgen_alloc_init_heavy_stats ();
2203 reset_pinned_from_failed_allocation (void)
2205 bytes_pinned_from_failed_allocation = 0;
2209 sgen_set_pinned_from_failed_allocation (mword objsize)
2211 bytes_pinned_from_failed_allocation += objsize;
2215 sgen_collection_is_parallel (void)
2217 switch (current_collection_generation) {
2218 case GENERATION_NURSERY:
2219 return nursery_collection_is_parallel;
2220 case GENERATION_OLD:
2221 return major_collector.is_parallel;
2223 g_error ("Invalid current generation %d", current_collection_generation);
2231 } FinishRememberedSetScanJobData;
2234 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2236 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2238 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2243 CopyOrMarkObjectFunc func;
2247 } ScanFromRegisteredRootsJobData;
2250 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2252 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2254 scan_from_registered_roots (job_data->func,
2255 job_data->heap_start, job_data->heap_end,
2256 job_data->root_type,
2257 sgen_workers_get_job_gray_queue (worker_data));
2264 } ScanThreadDataJobData;
2267 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2269 ScanThreadDataJobData *job_data = job_data_untyped;
2271 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2272 sgen_workers_get_job_gray_queue (worker_data));
2277 FinalizeReadyEntry *list;
2278 } ScanFinalizerEntriesJobData;
2281 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2283 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2285 scan_finalizer_entries (current_object_ops.copy_or_mark_object,
2287 sgen_workers_get_job_gray_queue (worker_data));
2291 verify_scan_starts (char *start, char *end)
2295 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2296 char *addr = nursery_section->scan_starts [i];
2297 if (addr > start && addr < end)
2298 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2303 verify_nursery (void)
2305 char *start, *end, *cur, *hole_start;
2307 if (!do_verify_nursery)
2310 /*This cleans up unused fragments */
2311 sgen_nursery_allocator_prepare_for_pinning ();
2313 hole_start = start = cur = sgen_get_nursery_start ();
2314 end = sgen_get_nursery_end ();
2319 if (!*(void**)cur) {
2320 cur += sizeof (void*);
2324 if (object_is_forwarded (cur))
2325 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2326 else if (object_is_pinned (cur))
2327 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2329 ss = safe_object_get_size ((MonoObject*)cur);
2330 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2331 verify_scan_starts (cur, cur + size);
2332 if (do_dump_nursery_content) {
2333 if (cur > hole_start)
2334 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2335 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == sgen_get_array_fill_vtable ());
2340 fflush (gc_debug_file);
2344 * Collect objects in the nursery. Returns whether to trigger a major
2348 collect_nursery (void)
2350 gboolean needs_major;
2351 size_t max_garbage_amount;
2353 FinishRememberedSetScanJobData frssjd;
2354 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2355 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2356 ScanThreadDataJobData stdjd;
2357 mword fragment_total;
2358 TV_DECLARE (all_atv);
2359 TV_DECLARE (all_btv);
2363 if (disable_minor_collections)
2366 MONO_GC_BEGIN (GENERATION_NURSERY);
2370 mono_perfcounters->gc_collections0++;
2372 current_collection_generation = GENERATION_NURSERY;
2373 if (sgen_collection_is_parallel ())
2374 current_object_ops = sgen_minor_collector.parallel_ops;
2376 current_object_ops = sgen_minor_collector.serial_ops;
2378 reset_pinned_from_failed_allocation ();
2380 binary_protocol_collection (GENERATION_NURSERY);
2381 check_scan_starts ();
2383 sgen_nursery_alloc_prepare_for_minor ();
2387 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2388 /* FIXME: optimize later to use the higher address where an object can be present */
2389 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2391 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, sgen_get_nursery_start (), nursery_next, (int)(nursery_next - sgen_get_nursery_start ())));
2392 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2393 g_assert (nursery_section->size >= max_garbage_amount);
2395 /* world must be stopped already */
2396 TV_GETTIME (all_atv);
2400 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2402 if (xdomain_checks) {
2403 sgen_clear_nursery_fragments ();
2404 check_for_xdomain_refs ();
2407 nursery_section->next_data = nursery_next;
2409 major_collector.start_nursery_collection ();
2411 sgen_memgov_minor_collection_start ();
2413 sgen_gray_object_queue_init (&gray_queue);
2414 sgen_workers_init_distribute_gray_queue ();
2417 gc_stats.minor_gc_count ++;
2419 if (remset.prepare_for_minor_collection)
2420 remset.prepare_for_minor_collection ();
2422 process_fin_stage_entries ();
2423 process_dislink_stage_entries ();
2425 /* pin from pinned handles */
2426 sgen_init_pinning ();
2427 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2428 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2429 /* identify pinned objects */
2430 sgen_optimize_pin_queue (0);
2431 sgen_pinning_setup_section (nursery_section);
2432 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2433 sgen_pinning_trim_queue_to_section (nursery_section);
2436 time_minor_pinning += TV_ELAPSED (btv, atv);
2437 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2438 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", sgen_get_pinned_count ()));
2440 if (whole_heap_check_before_collection)
2441 sgen_check_whole_heap ();
2442 if (consistency_check_at_minor_collection)
2443 sgen_check_consistency ();
2445 sgen_workers_start_all_workers ();
2448 * Perform the sequential part of remembered set scanning.
2449 * This usually involves scanning global information that might later be produced by evacuation.
2451 if (remset.begin_scan_remsets)
2452 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2454 sgen_workers_start_marking ();
2456 frssjd.heap_start = sgen_get_nursery_start ();
2457 frssjd.heap_end = nursery_next;
2458 sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2460 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2462 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2463 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2465 if (!sgen_collection_is_parallel ())
2466 sgen_drain_gray_stack (&gray_queue, -1);
2468 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2469 report_registered_roots ();
2470 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2471 report_finalizer_roots ();
2473 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2475 /* registered roots, this includes static fields */
2476 scrrjd_normal.func = current_object_ops.copy_or_mark_object;
2477 scrrjd_normal.heap_start = sgen_get_nursery_start ();
2478 scrrjd_normal.heap_end = nursery_next;
2479 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2480 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2482 scrrjd_wbarrier.func = current_object_ops.copy_or_mark_object;
2483 scrrjd_wbarrier.heap_start = sgen_get_nursery_start ();
2484 scrrjd_wbarrier.heap_end = nursery_next;
2485 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2486 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2489 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2492 stdjd.heap_start = sgen_get_nursery_start ();
2493 stdjd.heap_end = nursery_next;
2494 sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2497 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2500 if (sgen_collection_is_parallel ()) {
2501 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2502 sgen_workers_distribute_gray_queue_sections ();
2506 sgen_workers_join ();
2508 if (sgen_collection_is_parallel ())
2509 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2511 /* Scan the list of objects ready for finalization. If */
2512 sfejd_fin_ready.list = fin_ready_list;
2513 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2515 sfejd_critical_fin.list = critical_fin_list;
2516 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2518 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2520 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2521 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2524 * The (single-threaded) finalization code might have done
2525 * some copying/marking so we can only reset the GC thread's
2526 * worker data here instead of earlier when we joined the
2529 sgen_workers_reset_data ();
2531 if (objects_pinned) {
2532 sgen_optimize_pin_queue (0);
2533 sgen_pinning_setup_section (nursery_section);
2536 /* walk the pin_queue, build up the fragment list of free memory, unmark
2537 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2540 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2541 fragment_total = sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2542 if (!fragment_total)
2545 /* Clear TLABs for all threads */
2546 sgen_clear_tlabs ();
2548 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2550 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2551 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2553 if (consistency_check_at_minor_collection)
2554 sgen_check_major_refs ();
2556 major_collector.finish_nursery_collection ();
2558 TV_GETTIME (all_btv);
2559 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2562 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2564 /* prepare the pin queue for the next collection */
2565 sgen_finish_pinning ();
2566 if (fin_ready_list || critical_fin_list) {
2567 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2568 mono_gc_finalize_notify ();
2570 sgen_pin_stats_reset ();
2572 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2574 if (remset.finish_minor_collection)
2575 remset.finish_minor_collection ();
2577 check_scan_starts ();
2579 binary_protocol_flush_buffers (FALSE);
2581 sgen_memgov_minor_collection_end ();
2583 /*objects are late pinned because of lack of memory, so a major is a good call*/
2584 needs_major = objects_pinned > 0;
2585 current_collection_generation = -1;
2588 MONO_GC_END (GENERATION_NURSERY);
2594 major_do_collection (const char *reason)
2596 LOSObject *bigobj, *prevbo;
2597 TV_DECLARE (all_atv);
2598 TV_DECLARE (all_btv);
2601 /* FIXME: only use these values for the precise scan
2602 * note that to_space pointers should be excluded anyway...
2604 char *heap_start = NULL;
2605 char *heap_end = (char*)-1;
2606 int old_next_pin_slot;
2607 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2608 ScanThreadDataJobData stdjd;
2609 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2611 MONO_GC_BEGIN (GENERATION_OLD);
2613 current_collection_generation = GENERATION_OLD;
2614 mono_perfcounters->gc_collections1++;
2616 current_object_ops = major_collector.major_ops;
2618 reset_pinned_from_failed_allocation ();
2620 sgen_memgov_major_collection_start ();
2622 //count_ref_nonref_objs ();
2623 //consistency_check ();
2625 binary_protocol_collection (GENERATION_OLD);
2626 check_scan_starts ();
2628 sgen_gray_object_queue_init (&gray_queue);
2629 sgen_workers_init_distribute_gray_queue ();
2630 sgen_nursery_alloc_prepare_for_major ();
2633 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
2635 gc_stats.major_gc_count ++;
2637 /* world must be stopped already */
2638 TV_GETTIME (all_atv);
2641 /* Pinning depends on this */
2642 sgen_clear_nursery_fragments ();
2644 if (whole_heap_check_before_collection)
2645 sgen_check_whole_heap ();
2648 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2650 nursery_section->next_data = sgen_get_nursery_end ();
2651 /* we should also coalesce scanning from sections close to each other
2652 * and deal with pointers outside of the sections later.
2655 if (major_collector.start_major_collection)
2656 major_collector.start_major_collection ();
2659 *major_collector.have_swept = FALSE;
2661 if (xdomain_checks) {
2662 sgen_clear_nursery_fragments ();
2663 check_for_xdomain_refs ();
2666 /* Remsets are not useful for a major collection */
2667 remset.prepare_for_major_collection ();
2669 process_fin_stage_entries ();
2670 process_dislink_stage_entries ();
2673 sgen_init_pinning ();
2674 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
2675 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2676 sgen_optimize_pin_queue (0);
2679 * pin_queue now contains all candidate pointers, sorted and
2680 * uniqued. We must do two passes now to figure out which
2681 * objects are pinned.
2683 * The first is to find within the pin_queue the area for each
2684 * section. This requires that the pin_queue be sorted. We
2685 * also process the LOS objects and pinned chunks here.
2687 * The second, destructive, pass is to reduce the section
2688 * areas to pointers to the actually pinned objects.
2690 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
2691 /* first pass for the sections */
2692 sgen_find_section_pin_queue_start_end (nursery_section);
2693 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2694 /* identify possible pointers to the insize of large objects */
2695 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
2696 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2698 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2699 GCRootReport report;
2701 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
2702 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
2703 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2704 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2705 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2707 pin_object (bigobj->data);
2708 /* FIXME: only enqueue if object has references */
2709 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2710 if (G_UNLIKELY (do_pin_stats))
2711 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2712 DEBUG (6, fprintf (gc_debug_file, "Marked large object %p (%s) size: %lu from roots\n", bigobj->data, safe_name (bigobj->data), (unsigned long)bigobj->size));
2715 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2718 notify_gc_roots (&report);
2720 /* second pass for the sections */
2721 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2722 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2723 old_next_pin_slot = sgen_get_pinned_count ();
2726 time_major_pinning += TV_ELAPSED (atv, btv);
2727 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2728 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", sgen_get_pinned_count ()));
2730 major_collector.init_to_space ();
2732 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2733 main_gc_thread = mono_native_thread_self ();
2736 sgen_workers_start_all_workers ();
2737 sgen_workers_start_marking ();
2739 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2740 report_registered_roots ();
2742 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2744 /* registered roots, this includes static fields */
2745 scrrjd_normal.func = current_object_ops.copy_or_mark_object;
2746 scrrjd_normal.heap_start = heap_start;
2747 scrrjd_normal.heap_end = heap_end;
2748 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2749 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2751 scrrjd_wbarrier.func = current_object_ops.copy_or_mark_object;
2752 scrrjd_wbarrier.heap_start = heap_start;
2753 scrrjd_wbarrier.heap_end = heap_end;
2754 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2755 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2758 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2761 stdjd.heap_start = heap_start;
2762 stdjd.heap_end = heap_end;
2763 sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2766 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2769 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2771 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2772 report_finalizer_roots ();
2774 /* scan the list of objects ready for finalization */
2775 sfejd_fin_ready.list = fin_ready_list;
2776 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2778 sfejd_critical_fin.list = critical_fin_list;
2779 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2782 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2783 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
2786 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2788 if (major_collector.is_parallel) {
2789 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2790 sgen_workers_distribute_gray_queue_sections ();
2794 sgen_workers_join ();
2796 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2797 main_gc_thread = NULL;
2800 if (major_collector.is_parallel)
2801 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2803 /* all the objects in the heap */
2804 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2806 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2809 * The (single-threaded) finalization code might have done
2810 * some copying/marking so we can only reset the GC thread's
2811 * worker data here instead of earlier when we joined the
2814 sgen_workers_reset_data ();
2816 if (objects_pinned) {
2817 /*This is slow, but we just OOM'd*/
2818 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2819 sgen_optimize_pin_queue (0);
2820 sgen_find_section_pin_queue_start_end (nursery_section);
2824 reset_heap_boundaries ();
2825 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2827 /* sweep the big objects list */
2829 for (bigobj = los_object_list; bigobj;) {
2830 if (object_is_pinned (bigobj->data)) {
2831 unpin_object (bigobj->data);
2832 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
2835 /* not referenced anywhere, so we can free it */
2837 prevbo->next = bigobj->next;
2839 los_object_list = bigobj->next;
2841 bigobj = bigobj->next;
2842 sgen_los_free_object (to_free);
2846 bigobj = bigobj->next;
2850 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
2855 time_major_los_sweep += TV_ELAPSED (btv, atv);
2857 major_collector.sweep ();
2860 time_major_sweep += TV_ELAPSED (atv, btv);
2862 /* walk the pin_queue, build up the fragment list of free memory, unmark
2863 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2866 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
2869 /* Clear TLABs for all threads */
2870 sgen_clear_tlabs ();
2873 time_major_fragment_creation += TV_ELAPSED (btv, atv);
2875 TV_GETTIME (all_btv);
2876 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2879 dump_heap ("major", stat_major_gcs - 1, reason);
2881 /* prepare the pin queue for the next collection */
2882 sgen_finish_pinning ();
2884 if (fin_ready_list || critical_fin_list) {
2885 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2886 mono_gc_finalize_notify ();
2888 sgen_pin_stats_reset ();
2890 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2892 sgen_memgov_major_collection_end ();
2893 current_collection_generation = -1;
2895 major_collector.finish_major_collection ();
2897 check_scan_starts ();
2899 binary_protocol_flush_buffers (FALSE);
2901 //consistency_check ();
2903 MONO_GC_END (GENERATION_OLD);
2905 return bytes_pinned_from_failed_allocation > 0;
2908 static gboolean major_do_collection (const char *reason);
2911 * Ensure an allocation request for @size will succeed by freeing enough memory.
2913 * LOCKING: The GC lock MUST be held.
2916 sgen_ensure_free_space (size_t size)
2918 int generation_to_collect = -1;
2919 const char *reason = NULL;
2922 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
2923 if (sgen_need_major_collection (size)) {
2924 reason = "LOS overflow";
2925 generation_to_collect = GENERATION_OLD;
2928 if (degraded_mode) {
2929 if (sgen_need_major_collection (size)) {
2930 reason = "Degraded mode overflow";
2931 generation_to_collect = GENERATION_OLD;
2933 } else if (sgen_need_major_collection (size)) {
2934 reason = "Minor allowance";
2935 generation_to_collect = GENERATION_OLD;
2937 generation_to_collect = GENERATION_NURSERY;
2938 reason = "Nursery full";
2942 if (generation_to_collect == -1)
2944 sgen_perform_collection (size, generation_to_collect, reason);
2948 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason)
2950 TV_DECLARE (gc_end);
2951 GGTimingInfo infos [2];
2952 int overflow_generation_to_collect = -1;
2953 const char *overflow_reason = NULL;
2955 memset (infos, 0, sizeof (infos));
2956 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
2958 infos [0].generation = generation_to_collect;
2959 infos [0].reason = reason;
2960 infos [0].is_overflow = FALSE;
2961 TV_GETTIME (infos [0].total_time);
2962 infos [1].generation = -1;
2964 stop_world (generation_to_collect);
2965 //FIXME extract overflow reason
2966 if (generation_to_collect == GENERATION_NURSERY) {
2967 if (collect_nursery ()) {
2968 overflow_generation_to_collect = GENERATION_OLD;
2969 overflow_reason = "Minor overflow";
2972 if (major_do_collection (reason)) {
2973 overflow_generation_to_collect = GENERATION_NURSERY;
2974 overflow_reason = "Excessive pinning";
2978 TV_GETTIME (gc_end);
2979 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
2982 if (overflow_generation_to_collect != -1) {
2983 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
2984 infos [1].generation = overflow_generation_to_collect;
2985 infos [1].reason = overflow_reason;
2986 infos [1].is_overflow = TRUE;
2987 infos [1].total_time = gc_end;
2989 if (overflow_generation_to_collect == GENERATION_NURSERY)
2992 major_do_collection (overflow_reason);
2994 TV_GETTIME (gc_end);
2995 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
2997 /* keep events symmetric */
2998 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3001 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage));
3003 /* this also sets the proper pointers for the next allocation */
3004 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3005 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3006 DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", requested_size, sgen_get_pinned_count ()));
3007 sgen_dump_pin_queue ();
3011 restart_world (generation_to_collect, infos);
3013 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3017 * ######################################################################
3018 * ######## Memory allocation from the OS
3019 * ######################################################################
3020 * This section of code deals with getting memory from the OS and
3021 * allocating memory for GC-internal data structures.
3022 * Internal memory can be handled with a freelist for small objects.
3028 G_GNUC_UNUSED static void
3029 report_internal_mem_usage (void)
3031 printf ("Internal memory usage:\n");
3032 sgen_report_internal_mem_usage ();
3033 printf ("Pinned memory usage:\n");
3034 major_collector.report_pinned_memory_usage ();
3038 * ######################################################################
3039 * ######## Finalization support
3040 * ######################################################################
3044 * If the object has been forwarded it means it's still referenced from a root.
3045 * If it is pinned it's still alive as well.
3046 * A LOS object is only alive if we have pinned it.
3047 * Return TRUE if @obj is ready to be finalized.
3049 static inline gboolean
3050 sgen_is_object_alive (void *object)
3052 if (ptr_in_nursery (object))
3053 return sgen_nursery_is_object_alive (object);
3054 /* Oldgen objects can be pinned and forwarded too */
3055 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3057 return major_collector.is_object_live (object);
3061 sgen_gc_is_object_ready_for_finalization (void *object)
3063 return !sgen_is_object_alive (object);
3067 has_critical_finalizer (MonoObject *obj)
3071 if (!mono_defaults.critical_finalizer_object)
3074 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3076 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3080 queue_finalization_entry (MonoObject *obj) {
3081 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3082 entry->object = obj;
3083 if (has_critical_finalizer (obj)) {
3084 entry->next = critical_fin_list;
3085 critical_fin_list = entry;
3087 entry->next = fin_ready_list;
3088 fin_ready_list = entry;
3093 object_is_reachable (char *object, char *start, char *end)
3095 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3096 if (object < start || object >= end)
3099 return sgen_is_object_alive (object);
3102 #include "sgen-fin-weak-hash.c"
3105 sgen_object_is_live (void *obj)
3107 if (ptr_in_nursery (obj))
3108 return object_is_pinned (obj);
3109 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3110 if (current_collection_generation == GENERATION_NURSERY)
3112 return major_collector.is_object_live (obj);
3115 /* LOCKING: requires that the GC lock is held */
3117 null_ephemerons_for_domain (MonoDomain *domain)
3119 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3122 MonoObject *object = (MonoObject*)current->array;
3124 if (object && !object->vtable) {
3125 EphemeronLinkNode *tmp = current;
3128 prev->next = current->next;
3130 ephemeron_list = current->next;
3132 current = current->next;
3133 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3136 current = current->next;
3141 /* LOCKING: requires that the GC lock is held */
3143 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3145 int was_in_nursery, was_promoted;
3146 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3148 Ephemeron *cur, *array_end;
3152 char *object = current->array;
3154 if (!object_is_reachable (object, start, end)) {
3155 EphemeronLinkNode *tmp = current;
3157 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3160 prev->next = current->next;
3162 ephemeron_list = current->next;
3164 current = current->next;
3165 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3170 was_in_nursery = ptr_in_nursery (object);
3171 copy_func ((void**)&object, queue);
3172 current->array = object;
3174 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3175 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3177 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3179 array = (MonoArray*)object;
3180 cur = mono_array_addr (array, Ephemeron, 0);
3181 array_end = cur + mono_array_length_fast (array);
3182 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3184 for (; cur < array_end; ++cur) {
3185 char *key = (char*)cur->key;
3187 if (!key || key == tombstone)
3190 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3191 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3192 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3194 if (!object_is_reachable (key, start, end)) {
3195 cur->key = tombstone;
3201 if (ptr_in_nursery (key)) {/*key was not promoted*/
3202 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3203 sgen_add_to_global_remset (&cur->key);
3205 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3206 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3207 sgen_add_to_global_remset (&cur->value);
3212 current = current->next;
3216 /* LOCKING: requires that the GC lock is held */
3218 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3220 int nothing_marked = 1;
3221 EphemeronLinkNode *current = ephemeron_list;
3223 Ephemeron *cur, *array_end;
3226 for (current = ephemeron_list; current; current = current->next) {
3227 char *object = current->array;
3228 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3231 For now we process all ephemerons during all collections.
3232 Ideally we should use remset information to partially scan those
3234 We already emit write barriers for Ephemeron fields, it's
3235 just that we don't process them.
3237 /*if (object < start || object >= end)
3240 /*It has to be alive*/
3241 if (!object_is_reachable (object, start, end)) {
3242 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3246 copy_func ((void**)&object, queue);
3248 array = (MonoArray*)object;
3249 cur = mono_array_addr (array, Ephemeron, 0);
3250 array_end = cur + mono_array_length_fast (array);
3251 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3253 for (; cur < array_end; ++cur) {
3254 char *key = cur->key;
3256 if (!key || key == tombstone)
3259 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3260 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3261 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3263 if (object_is_reachable (key, start, end)) {
3264 char *value = cur->value;
3266 copy_func ((void**)&cur->key, queue);
3268 if (!object_is_reachable (value, start, end))
3270 copy_func ((void**)&cur->value, queue);
3276 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3277 return nothing_marked;
3281 mono_gc_invoke_finalizers (void)
3283 FinalizeReadyEntry *entry = NULL;
3284 gboolean entry_is_critical = FALSE;
3287 /* FIXME: batch to reduce lock contention */
3288 while (fin_ready_list || critical_fin_list) {
3292 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3294 /* We have finalized entry in the last
3295 interation, now we need to remove it from
3298 *list = entry->next;
3300 FinalizeReadyEntry *e = *list;
3301 while (e->next != entry)
3303 e->next = entry->next;
3305 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3309 /* Now look for the first non-null entry. */
3310 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3313 entry_is_critical = FALSE;
3315 entry_is_critical = TRUE;
3316 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3321 g_assert (entry->object);
3322 num_ready_finalizers--;
3323 obj = entry->object;
3324 entry->object = NULL;
3325 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3333 g_assert (entry->object == NULL);
3335 /* the object is on the stack so it is pinned */
3336 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3337 mono_gc_run_finalize (obj, NULL);
3344 mono_gc_pending_finalizers (void)
3346 return fin_ready_list || critical_fin_list;
3350 * ######################################################################
3351 * ######## registered roots support
3352 * ######################################################################
3356 * We do not coalesce roots.
3359 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3361 RootRecord new_root;
3364 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3365 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3366 /* we allow changing the size and the descriptor (for thread statics etc) */
3368 size_t old_size = root->end_root - start;
3369 root->end_root = start + size;
3370 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3371 ((root->root_desc == 0) && (descr == NULL)));
3372 root->root_desc = (mword)descr;
3374 roots_size -= old_size;
3380 new_root.end_root = start + size;
3381 new_root.root_desc = (mword)descr;
3383 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3386 DEBUG (3, fprintf (gc_debug_file, "Added root for range: %p-%p, descr: %p (%d/%d bytes)\n", start, new_root.end_root, descr, (int)size, (int)roots_size));
3393 mono_gc_register_root (char *start, size_t size, void *descr)
3395 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3399 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3401 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3405 mono_gc_deregister_root (char* addr)
3411 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3412 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3413 roots_size -= (root.end_root - addr);
3419 * ######################################################################
3420 * ######## Thread handling (stop/start code)
3421 * ######################################################################
3424 unsigned int sgen_global_stop_count = 0;
3427 static MonoContext cur_thread_ctx = {0};
3429 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3433 update_current_thread_stack (void *start)
3435 int stack_guard = 0;
3436 #ifndef USE_MONO_CTX
3437 void *ptr = cur_thread_regs;
3439 SgenThreadInfo *info = mono_thread_info_current ();
3441 info->stack_start = align_pointer (&stack_guard);
3442 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3444 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3445 info->monoctx = &cur_thread_ctx;
3446 if (gc_callbacks.thread_suspend_func)
3447 gc_callbacks.thread_suspend_func (info->runtime_data, NULL, info->monoctx);
3449 ARCH_STORE_REGS (ptr);
3450 info->stopped_regs = ptr;
3451 if (gc_callbacks.thread_suspend_func)
3452 gc_callbacks.thread_suspend_func (info->runtime_data, NULL, NULL);
3457 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3459 if (remset.fill_thread_info_for_suspend)
3460 remset.fill_thread_info_for_suspend (info);
3464 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3467 restart_threads_until_none_in_managed_allocator (void)
3469 SgenThreadInfo *info;
3470 int num_threads_died = 0;
3471 int sleep_duration = -1;
3474 int restart_count = 0, restarted_count = 0;
3475 /* restart all threads that stopped in the
3477 FOREACH_THREAD_SAFE (info) {
3479 if (info->skip || info->gc_disabled || !info->joined_stw)
3481 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3482 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3483 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3484 result = sgen_resume_thread (info);
3491 /* we set the stopped_ip to
3492 NULL for threads which
3493 we're not restarting so
3494 that we can easily identify
3496 info->stopped_ip = NULL;
3497 info->stopped_domain = NULL;
3499 } END_FOREACH_THREAD_SAFE
3500 /* if no threads were restarted, we're done */
3501 if (restart_count == 0)
3504 /* wait for the threads to signal their restart */
3505 sgen_wait_for_suspend_ack (restart_count);
3507 if (sleep_duration < 0) {
3515 g_usleep (sleep_duration);
3516 sleep_duration += 10;
3519 /* stop them again */
3520 FOREACH_THREAD (info) {
3522 if (info->skip || info->stopped_ip == NULL)
3524 result = sgen_suspend_thread (info);
3531 } END_FOREACH_THREAD
3532 /* some threads might have died */
3533 num_threads_died += restart_count - restarted_count;
3534 /* wait for the threads to signal their suspension
3536 sgen_wait_for_suspend_ack (restarted_count);
3539 return num_threads_died;
3543 acquire_gc_locks (void)
3546 mono_thread_info_suspend_lock ();
3550 release_gc_locks (void)
3552 mono_thread_info_suspend_unlock ();
3553 UNLOCK_INTERRUPTION;
3556 static TV_DECLARE (stop_world_time);
3557 static unsigned long max_pause_usec = 0;
3559 /* LOCKING: assumes the GC lock is held */
3561 stop_world (int generation)
3565 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3566 sgen_process_togglerefs ();
3568 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3569 acquire_gc_locks ();
3571 update_current_thread_stack (&count);
3573 sgen_global_stop_count++;
3574 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3575 TV_GETTIME (stop_world_time);
3576 count = sgen_thread_handshake (TRUE);
3577 dead = restart_threads_until_none_in_managed_allocator ();
3579 g_error ("More threads have died (%d) that been initialy suspended %d", dead, count);
3582 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3583 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3585 sgen_memgov_collection_start (generation);
3590 /* LOCKING: assumes the GC lock is held */
3592 restart_world (int generation, GGTimingInfo *timing)
3595 SgenThreadInfo *info;
3596 TV_DECLARE (end_sw);
3597 TV_DECLARE (end_bridge);
3598 unsigned long usec, bridge_usec;
3600 /* notify the profiler of the leftovers */
3601 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3602 if (moved_objects_idx) {
3603 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3604 moved_objects_idx = 0;
3607 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3608 FOREACH_THREAD (info) {
3609 info->stack_start = NULL;
3611 info->monoctx = NULL;
3613 info->stopped_regs = NULL;
3615 } END_FOREACH_THREAD
3617 stw_bridge_process ();
3618 release_gc_locks ();
3620 count = sgen_thread_handshake (FALSE);
3621 TV_GETTIME (end_sw);
3622 usec = TV_ELAPSED (stop_world_time, end_sw);
3623 max_pause_usec = MAX (usec, max_pause_usec);
3624 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3625 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3627 bridge_process (generation);
3629 TV_GETTIME (end_bridge);
3630 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3633 timing [0].stw_time = usec;
3634 timing [0].bridge_time = bridge_usec;
3637 sgen_memgov_collection_end (generation, timing, timing ? 2 : 0);
3643 sgen_get_current_collection_generation (void)
3645 return current_collection_generation;
3649 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3651 gc_callbacks = *callbacks;
3655 mono_gc_get_gc_callbacks ()
3657 return &gc_callbacks;
3660 /* Variables holding start/end nursery so it won't have to be passed at every call */
3661 static void *scan_area_arg_start, *scan_area_arg_end;
3664 mono_gc_conservatively_scan_area (void *start, void *end)
3666 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3670 mono_gc_scan_object (void *obj)
3672 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3673 current_object_ops.copy_or_mark_object (&obj, data->queue);
3678 * Mark from thread stacks and registers.
3681 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3683 SgenThreadInfo *info;
3685 scan_area_arg_start = start_nursery;
3686 scan_area_arg_end = end_nursery;
3688 FOREACH_THREAD (info) {
3690 DEBUG (3, fprintf (gc_debug_file, "Skipping dead thread %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3693 if (info->gc_disabled) {
3694 DEBUG (3, fprintf (gc_debug_file, "GC disabled for thread %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3698 if (!info->joined_stw) {
3699 DEBUG (3, fprintf (gc_debug_file, "Skipping thread not seen in STW %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3703 DEBUG (3, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %td, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, sgen_get_pinned_count ()));
3704 if (!info->thread_is_dying) {
3705 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3706 UserCopyOrMarkData data = { NULL, queue };
3707 set_user_copy_or_mark_data (&data);
3708 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3709 set_user_copy_or_mark_data (NULL);
3710 } else if (!precise) {
3711 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3716 if (!info->thread_is_dying && !precise)
3717 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3718 start_nursery, end_nursery, PIN_TYPE_STACK);
3720 if (!info->thread_is_dying && !precise)
3721 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3722 start_nursery, end_nursery, PIN_TYPE_STACK);
3724 } END_FOREACH_THREAD
3728 find_pinning_ref_from_thread (char *obj, size_t size)
3731 SgenThreadInfo *info;
3732 char *endobj = obj + size;
3734 FOREACH_THREAD (info) {
3735 char **start = (char**)info->stack_start;
3738 while (start < (char**)info->stack_end) {
3739 if (*start >= obj && *start < endobj) {
3740 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in thread %p (id %p) at %p, stack: %p-%p\n", obj, info, (gpointer)mono_thread_info_get_tid (info), start, info->stack_start, info->stack_end));
3745 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3747 mword w = ((mword*)info->monoctx) [j];
3749 mword w = (mword)info->stopped_regs [j];
3752 if (w >= (mword)obj && w < (mword)obj + size)
3753 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in saved reg %d of thread %p (id %p)\n", obj, j, info, (gpointer)mono_thread_info_get_tid (info)));
3754 } END_FOREACH_THREAD
3759 ptr_on_stack (void *ptr)
3761 gpointer stack_start = &stack_start;
3762 SgenThreadInfo *info = mono_thread_info_current ();
3764 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3770 sgen_thread_register (SgenThreadInfo* info, void *addr)
3772 #ifndef HAVE_KW_THREAD
3773 SgenThreadInfo *__thread_info__ = info;
3777 #ifndef HAVE_KW_THREAD
3778 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3780 g_assert (!mono_native_tls_get_value (thread_info_key));
3781 mono_native_tls_set_value (thread_info_key, info);
3786 #if !defined(__MACH__)
3787 info->stop_count = -1;
3791 info->joined_stw = FALSE;
3792 info->doing_handshake = FALSE;
3793 info->thread_is_dying = FALSE;
3794 info->stack_start = NULL;
3795 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3796 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3797 info->stopped_ip = NULL;
3798 info->stopped_domain = NULL;
3800 info->monoctx = NULL;
3802 info->stopped_regs = NULL;
3805 sgen_init_tlab_info (info);
3807 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3809 #ifdef HAVE_KW_THREAD
3810 store_remset_buffer_index_addr = &store_remset_buffer_index;
3813 #if defined(__MACH__)
3814 info->mach_port = mach_thread_self ();
3817 /* try to get it with attributes first */
3818 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
3822 pthread_attr_t attr;
3823 pthread_getattr_np (pthread_self (), &attr);
3824 pthread_attr_getstack (&attr, &sstart, &size);
3825 info->stack_start_limit = sstart;
3826 info->stack_end = (char*)sstart + size;
3827 pthread_attr_destroy (&attr);
3829 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
3830 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
3831 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
3834 /* FIXME: we assume the stack grows down */
3835 gsize stack_bottom = (gsize)addr;
3836 stack_bottom += 4095;
3837 stack_bottom &= ~4095;
3838 info->stack_end = (char*)stack_bottom;
3842 #ifdef HAVE_KW_THREAD
3843 stack_end = info->stack_end;
3846 if (remset.register_thread)
3847 remset.register_thread (info);
3849 DEBUG (3, fprintf (gc_debug_file, "registered thread %p (%p) stack end %p\n", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end));
3851 if (gc_callbacks.thread_attach_func)
3852 info->runtime_data = gc_callbacks.thread_attach_func ();
3859 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
3861 if (remset.cleanup_thread)
3862 remset.cleanup_thread (p);
3866 sgen_thread_unregister (SgenThreadInfo *p)
3868 /* If a delegate is passed to native code and invoked on a thread we dont
3869 * know about, the jit will register it with mono_jit_thread_attach, but
3870 * we have no way of knowing when that thread goes away. SGen has a TSD
3871 * so we assume that if the domain is still registered, we can detach
3874 if (mono_domain_get ())
3875 mono_thread_detach (mono_thread_current ());
3877 p->thread_is_dying = TRUE;
3880 There is a race condition between a thread finishing executing and been removed
3881 from the GC thread set.
3882 This happens on posix systems when TLS data is been cleaned-up, libpthread will
3883 set the thread_info slot to NULL before calling the cleanup function. This
3884 opens a window in which the thread is registered but has a NULL TLS.
3886 The suspend signal handler needs TLS data to know where to store thread state
3887 data or otherwise it will simply ignore the thread.
3889 This solution works because the thread doing STW will wait until all threads been
3890 suspended handshake back, so there is no race between the doing_hankshake test
3891 and the suspend_thread call.
3893 This is not required on systems that do synchronous STW as those can deal with
3894 the above race at suspend time.
3896 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
3897 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
3899 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
3902 while (!TRYLOCK_GC) {
3903 if (!sgen_park_current_thread_if_doing_handshake (p))
3909 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
3910 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
3912 #if defined(__MACH__)
3913 mach_port_deallocate (current_task (), p->mach_port);
3916 if (gc_callbacks.thread_detach_func) {
3917 gc_callbacks.thread_detach_func (p->runtime_data);
3918 p->runtime_data = NULL;
3920 sgen_wbarrier_cleanup_thread (p);
3922 mono_threads_unregister_current_thread (p);
3928 sgen_thread_attach (SgenThreadInfo *info)
3931 /*this is odd, can we get attached before the gc is inited?*/
3935 if (gc_callbacks.thread_attach_func && !info->runtime_data)
3936 info->runtime_data = gc_callbacks.thread_attach_func ();
3939 mono_gc_register_thread (void *baseptr)
3941 return mono_thread_info_attach (baseptr) != NULL;
3945 * mono_gc_set_stack_end:
3947 * Set the end of the current threads stack to STACK_END. The stack space between
3948 * STACK_END and the real end of the threads stack will not be scanned during collections.
3951 mono_gc_set_stack_end (void *stack_end)
3953 SgenThreadInfo *info;
3956 info = mono_thread_info_current ();
3958 g_assert (stack_end < info->stack_end);
3959 info->stack_end = stack_end;
3964 #if USE_PTHREAD_INTERCEPT
3968 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
3970 return pthread_create (new_thread, attr, start_routine, arg);
3974 mono_gc_pthread_join (pthread_t thread, void **retval)
3976 return pthread_join (thread, retval);
3980 mono_gc_pthread_detach (pthread_t thread)
3982 return pthread_detach (thread);
3986 mono_gc_pthread_exit (void *retval)
3988 pthread_exit (retval);
3991 #endif /* USE_PTHREAD_INTERCEPT */
3994 * ######################################################################
3995 * ######## Write barriers
3996 * ######################################################################
4000 * Note: the write barriers first do the needed GC work and then do the actual store:
4001 * this way the value is visible to the conservative GC scan after the write barrier
4002 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4003 * the conservative scan, otherwise by the remembered set scan.
4006 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4008 HEAVY_STAT (++stat_wbarrier_set_field);
4009 if (ptr_in_nursery (field_ptr)) {
4010 *(void**)field_ptr = value;
4013 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4015 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4017 remset.wbarrier_set_field (obj, field_ptr, value);
4021 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4023 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4024 if (ptr_in_nursery (slot_ptr)) {
4025 *(void**)slot_ptr = value;
4028 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4030 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4032 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4036 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4038 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4039 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4040 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4041 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4045 #ifdef SGEN_BINARY_PROTOCOL
4048 for (i = 0; i < count; ++i) {
4049 gpointer dest = (gpointer*)dest_ptr + i;
4050 gpointer obj = *((gpointer*)src_ptr + i);
4052 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4057 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4060 static char *found_obj;
4063 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4065 char *ptr = user_data;
4067 if (ptr >= obj && ptr < obj + size) {
4068 g_assert (!found_obj);
4073 /* for use in the debugger */
4074 char* find_object_for_ptr (char *ptr);
4076 find_object_for_ptr (char *ptr)
4078 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4080 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4081 find_object_for_ptr_callback, ptr, TRUE);
4087 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4092 * Very inefficient, but this is debugging code, supposed to
4093 * be called from gdb, so we don't care.
4096 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4101 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4103 HEAVY_STAT (++stat_wbarrier_generic_store);
4105 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4106 /* FIXME: ptr_in_heap must be called with the GC lock held */
4107 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4108 char *start = find_object_for_ptr (ptr);
4109 MonoObject *value = *(MonoObject**)ptr;
4113 MonoObject *obj = (MonoObject*)start;
4114 if (obj->vtable->domain != value->vtable->domain)
4115 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4121 if (*(gpointer*)ptr)
4122 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4124 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4125 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4129 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4131 remset.wbarrier_generic_nostore (ptr);
4135 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4137 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4138 *(void**)ptr = value;
4139 if (ptr_in_nursery (value))
4140 mono_gc_wbarrier_generic_nostore (ptr);
4141 sgen_dummy_use (value);
4144 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4146 mword *dest = _dest;
4151 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4156 size -= SIZEOF_VOID_P;
4161 #ifdef SGEN_BINARY_PROTOCOL
4163 #define HANDLE_PTR(ptr,obj) do { \
4164 gpointer o = *(gpointer*)(ptr); \
4166 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4167 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4172 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4174 #define SCAN_OBJECT_NOVTABLE
4175 #include "sgen-scan-object.h"
4180 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4182 HEAVY_STAT (++stat_wbarrier_value_copy);
4183 g_assert (klass->valuetype);
4185 DEBUG (8, fprintf (gc_debug_file, "Adding value remset at %p, count %d, descr %p for class %s (%p)\n", dest, count, klass->gc_descr, klass->name, klass));
4187 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4188 size_t element_size = mono_class_value_size (klass, NULL);
4189 size_t size = count * element_size;
4190 mono_gc_memmove (dest, src, size);
4194 #ifdef SGEN_BINARY_PROTOCOL
4197 for (i = 0; i < count; ++i) {
4198 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4199 (char*)src + i * element_size - sizeof (MonoObject),
4200 (mword) klass->gc_descr);
4205 remset.wbarrier_value_copy (dest, src, count, klass);
4209 * mono_gc_wbarrier_object_copy:
4211 * Write barrier to call when obj is the result of a clone or copy of an object.
4214 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4218 HEAVY_STAT (++stat_wbarrier_object_copy);
4220 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4221 size = mono_object_class (obj)->instance_size;
4222 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4223 size - sizeof (MonoObject));
4227 #ifdef SGEN_BINARY_PROTOCOL
4228 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4231 remset.wbarrier_object_copy (obj, src);
4236 * ######################################################################
4237 * ######## Other mono public interface functions.
4238 * ######################################################################
4241 #define REFS_SIZE 128
4244 MonoGCReferences callback;
4248 MonoObject *refs [REFS_SIZE];
4249 uintptr_t offsets [REFS_SIZE];
4253 #define HANDLE_PTR(ptr,obj) do { \
4255 if (hwi->count == REFS_SIZE) { \
4256 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4260 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4261 hwi->refs [hwi->count++] = *(ptr); \
4266 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4268 #include "sgen-scan-object.h"
4272 walk_references (char *start, size_t size, void *data)
4274 HeapWalkInfo *hwi = data;
4277 collect_references (hwi, start, size);
4278 if (hwi->count || !hwi->called)
4279 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4283 * mono_gc_walk_heap:
4284 * @flags: flags for future use
4285 * @callback: a function pointer called for each object in the heap
4286 * @data: a user data pointer that is passed to callback
4288 * This function can be used to iterate over all the live objects in the heap:
4289 * for each object, @callback is invoked, providing info about the object's
4290 * location in memory, its class, its size and the objects it references.
4291 * For each referenced object it's offset from the object address is
4292 * reported in the offsets array.
4293 * The object references may be buffered, so the callback may be invoked
4294 * multiple times for the same object: in all but the first call, the size
4295 * argument will be zero.
4296 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4297 * profiler event handler.
4299 * Returns: a non-zero value if the GC doesn't support heap walking
4302 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4307 hwi.callback = callback;
4310 sgen_clear_nursery_fragments ();
4311 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4313 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4314 sgen_los_iterate_objects (walk_references, &hwi);
4320 mono_gc_collect (int generation)
4325 sgen_perform_collection (0, generation, "user request");
4330 mono_gc_max_generation (void)
4336 mono_gc_collection_count (int generation)
4338 if (generation == 0)
4339 return stat_minor_gcs;
4340 return stat_major_gcs;
4344 mono_gc_get_used_size (void)
4348 tot = los_memory_usage;
4349 tot += nursery_section->next_data - nursery_section->data;
4350 tot += major_collector.get_used_size ();
4351 /* FIXME: account for pinned objects */
4357 mono_gc_disable (void)
4365 mono_gc_enable (void)
4373 mono_gc_get_los_limit (void)
4375 return MAX_SMALL_OBJ_SIZE;
4379 mono_gc_user_markers_supported (void)
4385 mono_object_is_alive (MonoObject* o)
4391 mono_gc_get_generation (MonoObject *obj)
4393 if (ptr_in_nursery (obj))
4399 mono_gc_enable_events (void)
4404 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4406 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4410 mono_gc_weak_link_remove (void **link_addr)
4412 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4416 mono_gc_weak_link_get (void **link_addr)
4419 * We must only load *link_addr once because it might change
4420 * under our feet, and REVEAL_POINTER (NULL) results in an
4421 * invalid reference.
4423 void *ptr = *link_addr;
4428 * During the second bridge processing step the world is
4429 * running again. That step processes all weak links once
4430 * more to null those that refer to dead objects. Before that
4431 * is completed, those links must not be followed, so we
4432 * conservatively wait for bridge processing when any weak
4433 * link is dereferenced.
4435 if (G_UNLIKELY (bridge_processing_in_progress))
4436 mono_gc_wait_for_bridge_processing ();
4438 return (MonoObject*) REVEAL_POINTER (ptr);
4442 mono_gc_ephemeron_array_add (MonoObject *obj)
4444 EphemeronLinkNode *node;
4448 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4453 node->array = (char*)obj;
4454 node->next = ephemeron_list;
4455 ephemeron_list = node;
4457 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4464 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4468 result = func (data);
4469 UNLOCK_INTERRUPTION;
4474 mono_gc_is_gc_thread (void)
4478 result = mono_thread_info_current () != NULL;
4484 is_critical_method (MonoMethod *method)
4486 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4490 mono_gc_base_init (void)
4492 MonoThreadInfoCallbacks cb;
4495 char *major_collector_opt = NULL;
4496 char *minor_collector_opt = NULL;
4498 glong soft_limit = 0;
4502 gboolean debug_print_allowance = FALSE;
4503 double allowance_ratio = 0, save_target = 0;
4506 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4509 /* already inited */
4512 /* being inited by another thread */
4516 /* we will init it */
4519 g_assert_not_reached ();
4521 } while (result != 0);
4523 LOCK_INIT (gc_mutex);
4525 pagesize = mono_pagesize ();
4526 gc_debug_file = stderr;
4528 cb.thread_register = sgen_thread_register;
4529 cb.thread_unregister = sgen_thread_unregister;
4530 cb.thread_attach = sgen_thread_attach;
4531 cb.mono_method_is_critical = (gpointer)is_critical_method;
4533 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4536 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4538 LOCK_INIT (interruption_mutex);
4539 LOCK_INIT (pin_queue_mutex);
4541 init_user_copy_or_mark_key ();
4543 if ((env = getenv ("MONO_GC_PARAMS"))) {
4544 opts = g_strsplit (env, ",", -1);
4545 for (ptr = opts; *ptr; ++ptr) {
4547 if (g_str_has_prefix (opt, "major=")) {
4548 opt = strchr (opt, '=') + 1;
4549 major_collector_opt = g_strdup (opt);
4550 } else if (g_str_has_prefix (opt, "minor=")) {
4551 opt = strchr (opt, '=') + 1;
4552 minor_collector_opt = g_strdup (opt);
4560 sgen_init_internal_allocator ();
4561 sgen_init_nursery_allocator ();
4563 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4564 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4565 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4566 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4567 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4568 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4570 #ifndef HAVE_KW_THREAD
4571 mono_native_tls_alloc (&thread_info_key, NULL);
4575 * This needs to happen before any internal allocations because
4576 * it inits the small id which is required for hazard pointer
4581 mono_thread_info_attach (&dummy);
4583 if (!minor_collector_opt) {
4584 sgen_simple_nursery_init (&sgen_minor_collector);
4586 if (!strcmp (minor_collector_opt, "simple"))
4587 sgen_simple_nursery_init (&sgen_minor_collector);
4588 else if (!strcmp (minor_collector_opt, "split"))
4589 sgen_split_nursery_init (&sgen_minor_collector);
4591 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4596 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4597 sgen_marksweep_init (&major_collector);
4598 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4599 sgen_marksweep_fixed_init (&major_collector);
4600 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4601 sgen_marksweep_par_init (&major_collector);
4602 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4603 sgen_marksweep_fixed_par_init (&major_collector);
4604 } else if (!strcmp (major_collector_opt, "copying")) {
4605 sgen_copying_init (&major_collector);
4607 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4611 #ifdef SGEN_HAVE_CARDTABLE
4612 use_cardtable = major_collector.supports_cardtable;
4614 use_cardtable = FALSE;
4617 num_workers = mono_cpu_count ();
4618 g_assert (num_workers > 0);
4619 if (num_workers > 16)
4622 ///* Keep this the default for now */
4623 /* Precise marking is broken on all supported targets. Disable until fixed. */
4624 conservative_stack_mark = TRUE;
4626 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4629 for (ptr = opts; *ptr; ++ptr) {
4631 if (g_str_has_prefix (opt, "major="))
4633 if (g_str_has_prefix (opt, "minor="))
4635 if (g_str_has_prefix (opt, "wbarrier=")) {
4636 opt = strchr (opt, '=') + 1;
4637 if (strcmp (opt, "remset") == 0) {
4638 use_cardtable = FALSE;
4639 } else if (strcmp (opt, "cardtable") == 0) {
4640 if (!use_cardtable) {
4641 if (major_collector.supports_cardtable)
4642 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4644 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4648 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4653 if (g_str_has_prefix (opt, "max-heap-size=")) {
4654 opt = strchr (opt, '=') + 1;
4655 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4656 if ((max_heap & (mono_pagesize () - 1))) {
4657 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4661 fprintf (stderr, "max-heap-size must be an integer.\n");
4666 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4667 opt = strchr (opt, '=') + 1;
4668 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4669 if (soft_limit <= 0) {
4670 fprintf (stderr, "soft-heap-limit must be positive.\n");
4674 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4679 if (g_str_has_prefix (opt, "workers=")) {
4682 if (!major_collector.is_parallel) {
4683 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4686 opt = strchr (opt, '=') + 1;
4687 val = strtol (opt, &endptr, 10);
4688 if (!*opt || *endptr) {
4689 fprintf (stderr, "Cannot parse the workers= option value.");
4692 if (val <= 0 || val > 16) {
4693 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4696 num_workers = (int)val;
4699 if (g_str_has_prefix (opt, "stack-mark=")) {
4700 opt = strchr (opt, '=') + 1;
4701 if (!strcmp (opt, "precise")) {
4702 conservative_stack_mark = FALSE;
4703 } else if (!strcmp (opt, "conservative")) {
4704 conservative_stack_mark = TRUE;
4706 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4711 if (g_str_has_prefix (opt, "bridge=")) {
4712 opt = strchr (opt, '=') + 1;
4713 sgen_register_test_bridge_callbacks (g_strdup (opt));
4717 if (g_str_has_prefix (opt, "nursery-size=")) {
4719 opt = strchr (opt, '=') + 1;
4720 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4721 sgen_nursery_size = val;
4722 #ifdef SGEN_ALIGN_NURSERY
4723 if ((val & (val - 1))) {
4724 fprintf (stderr, "The nursery size must be a power of two.\n");
4728 if (val < SGEN_MAX_NURSERY_WASTE) {
4729 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4733 sgen_nursery_bits = 0;
4734 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4738 fprintf (stderr, "nursery-size must be an integer.\n");
4744 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4746 opt = strchr (opt, '=') + 1;
4747 save_target = strtod (opt, &endptr);
4748 if (endptr == opt) {
4749 fprintf (stderr, "save-target-ratio must be a number.");
4752 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4753 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4758 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4760 opt = strchr (opt, '=') + 1;
4762 allowance_ratio = strtod (opt, &endptr);
4763 if (endptr == opt) {
4764 fprintf (stderr, "save-target-ratio must be a number.");
4767 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4768 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4774 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4777 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4780 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4781 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4782 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4783 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4784 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4785 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4786 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4787 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4788 if (major_collector.print_gc_param_usage)
4789 major_collector.print_gc_param_usage ();
4790 if (sgen_minor_collector.print_gc_param_usage)
4791 sgen_minor_collector.print_gc_param_usage ();
4792 fprintf (stderr, " Experimental options:\n");
4793 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4794 fprintf (stderr, " default-allowance-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MAX_ALLOWANCE_NURSERY_SIZE_RATIO);
4800 if (major_collector.is_parallel)
4801 sgen_workers_init (num_workers);
4803 if (major_collector_opt)
4804 g_free (major_collector_opt);
4806 if (minor_collector_opt)
4807 g_free (minor_collector_opt);
4811 if ((env = getenv ("MONO_GC_DEBUG"))) {
4812 opts = g_strsplit (env, ",", -1);
4813 for (ptr = opts; ptr && *ptr; ptr ++) {
4815 if (opt [0] >= '0' && opt [0] <= '9') {
4816 gc_debug_level = atoi (opt);
4822 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
4824 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4826 gc_debug_file = fopen (rf, "wb");
4828 gc_debug_file = stderr;
4831 } else if (!strcmp (opt, "print-allowance")) {
4832 debug_print_allowance = TRUE;
4833 } else if (!strcmp (opt, "print-pinning")) {
4834 do_pin_stats = TRUE;
4835 } else if (!strcmp (opt, "verify-before-allocs")) {
4836 verify_before_allocs = 1;
4837 has_per_allocation_action = TRUE;
4838 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
4839 char *arg = strchr (opt, '=') + 1;
4840 verify_before_allocs = atoi (arg);
4841 has_per_allocation_action = TRUE;
4842 } else if (!strcmp (opt, "collect-before-allocs")) {
4843 collect_before_allocs = 1;
4844 has_per_allocation_action = TRUE;
4845 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4846 char *arg = strchr (opt, '=') + 1;
4847 has_per_allocation_action = TRUE;
4848 collect_before_allocs = atoi (arg);
4849 } else if (!strcmp (opt, "verify-before-collections")) {
4850 whole_heap_check_before_collection = TRUE;
4851 } else if (!strcmp (opt, "check-at-minor-collections")) {
4852 consistency_check_at_minor_collection = TRUE;
4853 nursery_clear_policy = CLEAR_AT_GC;
4854 } else if (!strcmp (opt, "xdomain-checks")) {
4855 xdomain_checks = TRUE;
4856 } else if (!strcmp (opt, "clear-at-gc")) {
4857 nursery_clear_policy = CLEAR_AT_GC;
4858 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4859 nursery_clear_policy = CLEAR_AT_GC;
4860 } else if (!strcmp (opt, "check-scan-starts")) {
4861 do_scan_starts_check = TRUE;
4862 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4863 do_verify_nursery = TRUE;
4864 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4865 do_dump_nursery_content = TRUE;
4866 } else if (!strcmp (opt, "disable-minor")) {
4867 disable_minor_collections = TRUE;
4868 } else if (!strcmp (opt, "disable-major")) {
4869 disable_major_collections = TRUE;
4870 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4871 char *filename = strchr (opt, '=') + 1;
4872 nursery_clear_policy = CLEAR_AT_GC;
4873 heap_dump_file = fopen (filename, "w");
4874 if (heap_dump_file) {
4875 fprintf (heap_dump_file, "<sgen-dump>\n");
4876 do_pin_stats = TRUE;
4878 #ifdef SGEN_BINARY_PROTOCOL
4879 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4880 char *filename = strchr (opt, '=') + 1;
4881 binary_protocol_init (filename);
4883 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4886 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4887 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4888 fprintf (stderr, "Valid options are:\n");
4889 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4890 fprintf (stderr, " verify-before-allocs[=<n>]\n");
4891 fprintf (stderr, " check-at-minor-collections\n");
4892 fprintf (stderr, " verify-before-collections\n");
4893 fprintf (stderr, " disable-minor\n");
4894 fprintf (stderr, " disable-major\n");
4895 fprintf (stderr, " xdomain-checks\n");
4896 fprintf (stderr, " clear-at-gc\n");
4897 fprintf (stderr, " print-allowance\n");
4898 fprintf (stderr, " print-pinning\n");
4905 if (major_collector.is_parallel) {
4906 if (heap_dump_file) {
4907 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
4911 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
4916 if (major_collector.post_param_init)
4917 major_collector.post_param_init ();
4919 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
4921 memset (&remset, 0, sizeof (remset));
4923 #ifdef SGEN_HAVE_CARDTABLE
4925 sgen_card_table_init (&remset);
4928 sgen_ssb_init (&remset);
4930 if (remset.register_thread)
4931 remset.register_thread (mono_thread_info_current ());
4937 mono_gc_get_gc_name (void)
4942 static MonoMethod *write_barrier_method;
4945 mono_gc_is_critical_method (MonoMethod *method)
4947 return (method == write_barrier_method || sgen_is_managed_allocator (method));
4951 sgen_has_critical_method (void)
4953 return write_barrier_method || sgen_has_managed_allocator ();
4957 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
4961 if (!mono_thread_internal_current ())
4962 /* Happens during thread attach */
4967 if (!sgen_has_critical_method ())
4969 ji = mono_jit_info_table_find (domain, ip);
4973 return mono_gc_is_critical_method (ji->method);
4977 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
4979 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
4980 #ifdef SGEN_ALIGN_NURSERY
4981 // if (ptr_in_nursery (ptr)) return;
4983 * Masking out the bits might be faster, but we would have to use 64 bit
4984 * immediates, which might be slower.
4986 mono_mb_emit_ldarg (mb, 0);
4987 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
4988 mono_mb_emit_byte (mb, CEE_SHR_UN);
4989 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
4990 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
4992 // if (!ptr_in_nursery (*ptr)) return;
4993 mono_mb_emit_ldarg (mb, 0);
4994 mono_mb_emit_byte (mb, CEE_LDIND_I);
4995 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
4996 mono_mb_emit_byte (mb, CEE_SHR_UN);
4997 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
4998 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5000 int label_continue1, label_continue2;
5001 int dereferenced_var;
5003 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5004 mono_mb_emit_ldarg (mb, 0);
5005 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5006 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5008 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5009 mono_mb_emit_ldarg (mb, 0);
5010 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5011 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5014 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5017 mono_mb_patch_branch (mb, label_continue_1);
5018 mono_mb_patch_branch (mb, label_continue_2);
5020 // Dereference and store in local var
5021 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5022 mono_mb_emit_ldarg (mb, 0);
5023 mono_mb_emit_byte (mb, CEE_LDIND_I);
5024 mono_mb_emit_stloc (mb, dereferenced_var);
5026 // if (*ptr < sgen_get_nursery_start ()) return;
5027 mono_mb_emit_ldloc (mb, dereferenced_var);
5028 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5029 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5031 // if (*ptr >= sgen_get_nursery_end ()) return;
5032 mono_mb_emit_ldloc (mb, dereferenced_var);
5033 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5034 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5039 mono_gc_get_write_barrier (void)
5042 MonoMethodBuilder *mb;
5043 MonoMethodSignature *sig;
5044 #ifdef MANAGED_WBARRIER
5045 int i, nursery_check_labels [3];
5046 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5047 int buffer_var, buffer_index_var, dummy_var;
5049 #ifdef HAVE_KW_THREAD
5050 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5051 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5053 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5054 g_assert (stack_end_offset != -1);
5055 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5056 g_assert (store_remset_buffer_offset != -1);
5057 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5058 g_assert (store_remset_buffer_index_offset != -1);
5059 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5060 g_assert (store_remset_buffer_index_addr_offset != -1);
5064 // FIXME: Maybe create a separate version for ctors (the branch would be
5065 // correctly predicted more times)
5066 if (write_barrier_method)
5067 return write_barrier_method;
5069 /* Create the IL version of mono_gc_barrier_generic_store () */
5070 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5071 sig->ret = &mono_defaults.void_class->byval_arg;
5072 sig->params [0] = &mono_defaults.int_class->byval_arg;
5074 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5076 #ifdef MANAGED_WBARRIER
5077 if (use_cardtable) {
5078 emit_nursery_check (mb, nursery_check_labels);
5080 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5084 LDC_PTR sgen_cardtable
5086 address >> CARD_BITS
5090 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5091 LDC_PTR card_table_mask
5098 mono_mb_emit_ptr (mb, sgen_cardtable);
5099 mono_mb_emit_ldarg (mb, 0);
5100 mono_mb_emit_icon (mb, CARD_BITS);
5101 mono_mb_emit_byte (mb, CEE_SHR_UN);
5102 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5103 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5104 mono_mb_emit_byte (mb, CEE_AND);
5106 mono_mb_emit_byte (mb, CEE_ADD);
5107 mono_mb_emit_icon (mb, 1);
5108 mono_mb_emit_byte (mb, CEE_STIND_I1);
5111 for (i = 0; i < 3; ++i) {
5112 if (nursery_check_labels [i])
5113 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5115 mono_mb_emit_byte (mb, CEE_RET);
5116 } else if (mono_runtime_has_tls_get ()) {
5117 emit_nursery_check (mb, nursery_check_labels);
5119 // if (ptr >= stack_end) goto need_wb;
5120 mono_mb_emit_ldarg (mb, 0);
5121 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5122 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5124 // if (ptr >= stack_start) return;
5125 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5126 mono_mb_emit_ldarg (mb, 0);
5127 mono_mb_emit_ldloc_addr (mb, dummy_var);
5128 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5131 mono_mb_patch_branch (mb, label_need_wb);
5133 // buffer = STORE_REMSET_BUFFER;
5134 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5135 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5136 mono_mb_emit_stloc (mb, buffer_var);
5138 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5139 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5140 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5141 mono_mb_emit_stloc (mb, buffer_index_var);
5143 // if (buffer [buffer_index] == ptr) return;
5144 mono_mb_emit_ldloc (mb, buffer_var);
5145 mono_mb_emit_ldloc (mb, buffer_index_var);
5146 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5147 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5148 mono_mb_emit_byte (mb, CEE_SHL);
5149 mono_mb_emit_byte (mb, CEE_ADD);
5150 mono_mb_emit_byte (mb, CEE_LDIND_I);
5151 mono_mb_emit_ldarg (mb, 0);
5152 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5155 mono_mb_emit_ldloc (mb, buffer_index_var);
5156 mono_mb_emit_icon (mb, 1);
5157 mono_mb_emit_byte (mb, CEE_ADD);
5158 mono_mb_emit_stloc (mb, buffer_index_var);
5160 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5161 mono_mb_emit_ldloc (mb, buffer_index_var);
5162 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5163 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5165 // buffer [buffer_index] = ptr;
5166 mono_mb_emit_ldloc (mb, buffer_var);
5167 mono_mb_emit_ldloc (mb, buffer_index_var);
5168 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5169 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5170 mono_mb_emit_byte (mb, CEE_SHL);
5171 mono_mb_emit_byte (mb, CEE_ADD);
5172 mono_mb_emit_ldarg (mb, 0);
5173 mono_mb_emit_byte (mb, CEE_STIND_I);
5175 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5176 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5177 mono_mb_emit_ldloc (mb, buffer_index_var);
5178 mono_mb_emit_byte (mb, CEE_STIND_I);
5181 for (i = 0; i < 3; ++i) {
5182 if (nursery_check_labels [i])
5183 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5185 mono_mb_patch_branch (mb, label_no_wb_3);
5186 mono_mb_patch_branch (mb, label_no_wb_4);
5187 mono_mb_emit_byte (mb, CEE_RET);
5190 mono_mb_patch_branch (mb, label_slow_path);
5192 mono_mb_emit_ldarg (mb, 0);
5193 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5194 mono_mb_emit_byte (mb, CEE_RET);
5198 mono_mb_emit_ldarg (mb, 0);
5199 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5200 mono_mb_emit_byte (mb, CEE_RET);
5203 res = mono_mb_create_method (mb, sig, 16);
5206 mono_loader_lock ();
5207 if (write_barrier_method) {
5208 /* Already created */
5209 mono_free_method (res);
5211 /* double-checked locking */
5212 mono_memory_barrier ();
5213 write_barrier_method = res;
5215 mono_loader_unlock ();
5217 return write_barrier_method;
5221 mono_gc_get_description (void)
5223 return g_strdup ("sgen");
5227 mono_gc_set_desktop_mode (void)
5232 mono_gc_is_moving (void)
5238 mono_gc_is_disabled (void)
5244 sgen_debug_printf (int level, const char *format, ...)
5248 if (level > gc_debug_level)
5251 va_start (ap, format);
5252 vfprintf (gc_debug_file, format, ap);
5257 sgen_get_logfile (void)
5259 return gc_debug_file;
5263 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5270 sgen_get_nursery_clear_policy (void)
5272 return nursery_clear_policy;
5276 sgen_get_array_fill_vtable (void)
5278 if (!array_fill_vtable) {
5279 static MonoClass klass;
5280 static MonoVTable vtable;
5283 MonoDomain *domain = mono_get_root_domain ();
5286 klass.element_class = mono_defaults.byte_class;
5288 klass.instance_size = sizeof (MonoArray);
5289 klass.sizes.element_size = 1;
5290 klass.name = "array_filler_type";
5292 vtable.klass = &klass;
5294 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5297 array_fill_vtable = &vtable;
5299 return array_fill_vtable;
5309 sgen_gc_unlock (void)
5315 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5317 major_collector.iterate_live_block_ranges (callback);
5321 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5323 major_collector.scan_card_table (queue);
5327 sgen_get_major_collector (void)
5329 return &major_collector;
5332 void mono_gc_set_skip_thread (gboolean skip)
5334 SgenThreadInfo *info = mono_thread_info_current ();
5337 info->gc_disabled = skip;
5342 sgen_get_remset (void)
5348 mono_gc_get_vtable_bits (MonoClass *class)
5350 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5351 return SGEN_GC_BIT_BRIDGE_OBJECT;
5356 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5363 sgen_check_whole_heap_stw (void)
5366 sgen_clear_nursery_fragments ();
5367 sgen_check_whole_heap ();
5368 restart_world (0, NULL);
5371 #endif /* HAVE_SGEN_GC */