/* * boehm-gc.c: GC implementation using either the installed or included Boehm GC. * */ #include "config.h" #define GC_I_HIDE_POINTERS #include #include #include #include #include #include #include #include #if HAVE_BOEHM_GC #ifdef USE_INCLUDED_LIBGC #undef TRUE #undef FALSE #define THREAD_LOCAL_ALLOC 1 #include "private/pthread_support.h" #endif #define GC_NO_DESCRIPTOR ((gpointer)(0 | GC_DS_LENGTH)) static gboolean gc_initialized = FALSE; static void mono_gc_warning (char *msg, GC_word arg) { mono_trace (G_LOG_LEVEL_WARNING, MONO_TRACE_GC, msg, (unsigned long)arg); } void mono_gc_base_init (void) { if (gc_initialized) return; /* * Handle the case when we are called from a thread different from the main thread, * confusing libgc. * FIXME: Move this to libgc where it belongs. * * we used to do this only when running on valgrind, * but it happens also in other setups. */ #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK) { size_t size; void *sstart; pthread_attr_t attr; pthread_getattr_np (pthread_self (), &attr); pthread_attr_getstack (&attr, &sstart, &size); pthread_attr_destroy (&attr); /*g_print ("stackbottom pth is: %p\n", (char*)sstart + size);*/ #ifdef __ia64__ /* * The calculation above doesn't seem to work on ia64, also we need to set * GC_register_stackbottom as well, but don't know how. */ #else /* apparently with some linuxthreads implementations sstart can be NULL, * fallback to the more imprecise method (bug# 78096). */ if (sstart) { GC_stackbottom = (char*)sstart + size; } else { int dummy; gsize stack_bottom = (gsize)&dummy; stack_bottom += 4095; stack_bottom &= ~4095; GC_stackbottom = (char*)stack_bottom; } #endif } #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP) GC_stackbottom = (char*)pthread_get_stackaddr_np (pthread_self ()); #else { int dummy; gsize stack_bottom = (gsize)&dummy; stack_bottom += 4095; stack_bottom &= ~4095; /*g_print ("stackbottom is: %p\n", (char*)stack_bottom);*/ GC_stackbottom = (char*)stack_bottom; } #endif GC_init (); GC_no_dls = TRUE; GC_oom_fn = mono_gc_out_of_memory; GC_set_warn_proc (mono_gc_warning); GC_finalize_on_demand = 1; GC_finalizer_notifier = mono_gc_finalize_notify; #ifdef HAVE_GC_GCJ_MALLOC GC_init_gcj_malloc (5, NULL); #endif gc_initialized = TRUE; } void mono_gc_collect (int generation) { GC_gcollect (); } int mono_gc_max_generation (void) { return 0; } int mono_gc_get_generation (MonoObject *object) { return 0; } int mono_gc_collection_count (int generation) { return GC_gc_no; } void mono_gc_add_memory_pressure (gint64 value) { } gint64 mono_gc_get_used_size (void) { return GC_get_heap_size () - GC_get_free_bytes (); } gint64 mono_gc_get_heap_size (void) { return GC_get_heap_size (); } void mono_gc_disable (void) { #ifdef HAVE_GC_ENABLE GC_disable (); #else g_assert_not_reached (); #endif } void mono_gc_enable (void) { #ifdef HAVE_GC_ENABLE GC_enable (); #else g_assert_not_reached (); #endif } gboolean mono_gc_is_gc_thread (void) { #if GC_VERSION_MAJOR >= 7 return TRUE; #elif defined(USE_INCLUDED_LIBGC) return GC_thread_is_registered (); #else return TRUE; #endif } extern int GC_thread_register_foreign (void *base_addr); gboolean mono_gc_register_thread (void *baseptr) { #if GC_VERSION_MAJOR >= 7 struct GC_stack_base sb; int res; res = GC_get_stack_base (&sb); if (res != GC_SUCCESS) { sb.mem_base = baseptr; #ifdef __ia64__ /* Can't determine the register stack bounds */ g_error ("mono_gc_register_thread failed ().\n"); #endif } res = GC_register_my_thread (&sb); if ((res != GC_SUCCESS) && (res != GC_DUPLICATE)) { g_warning ("GC_register_my_thread () failed.\n"); return FALSE; } return TRUE; #else if (mono_gc_is_gc_thread()) return TRUE; #if defined(USE_INCLUDED_LIBGC) && !defined(PLATFORM_WIN32) return GC_thread_register_foreign (baseptr); #else return FALSE; #endif #endif } gboolean mono_object_is_alive (MonoObject* o) { #ifdef USE_INCLUDED_LIBGC return GC_is_marked ((gpointer)o); #else return TRUE; #endif } #ifdef USE_INCLUDED_LIBGC static void on_gc_notification (GCEventType event) { mono_profiler_gc_event ((MonoGCEvent) event, 0); } static void on_gc_heap_resize (size_t new_size) { mono_profiler_gc_heap_resize (new_size); } void mono_gc_enable_events (void) { GC_notify_event = on_gc_notification; GC_on_heap_resize = on_gc_heap_resize; } #else void mono_gc_enable_events (void) { } #endif int mono_gc_register_root (char *start, size_t size, void *descr) { /* for some strange reason, they want one extra byte on the end */ GC_add_roots (start, start + size + 1); return TRUE; } void mono_gc_deregister_root (char* addr) { /* FIXME: No size info */ GC_remove_roots (addr, addr + sizeof (gpointer)); } void mono_gc_weak_link_add (void **link_addr, MonoObject *obj) { /* libgc requires that we use HIDE_POINTER... */ *link_addr = (void*)HIDE_POINTER (obj); GC_GENERAL_REGISTER_DISAPPEARING_LINK (link_addr, obj); } void mono_gc_weak_link_remove (void **link_addr) { GC_unregister_disappearing_link (link_addr); *link_addr = NULL; } MonoObject* mono_gc_weak_link_get (void **link_addr) { MonoObject *obj = REVEAL_POINTER (*link_addr); if (obj == (MonoObject *) -1) return NULL; return obj; } void* mono_gc_make_descr_for_string (gsize *bitmap, int numbits) { return mono_gc_make_descr_from_bitmap (bitmap, numbits); } void* mono_gc_make_descr_for_object (gsize *bitmap, int numbits, size_t obj_size) { return mono_gc_make_descr_from_bitmap (bitmap, numbits); } void* mono_gc_make_descr_for_array (int vector, gsize *elem_bitmap, int numbits, size_t elem_size) { /* libgc has no usable support for arrays... */ return GC_NO_DESCRIPTOR; } void* mono_gc_make_descr_from_bitmap (gsize *bitmap, int numbits) { #ifdef HAVE_GC_GCJ_MALLOC /* It seems there are issues when the bitmap doesn't fit: play it safe */ if (numbits >= 30) return GC_NO_DESCRIPTOR; else return (gpointer)GC_make_descriptor ((GC_bitmap)bitmap, numbits); #else return NULL; #endif } void* mono_gc_alloc_fixed (size_t size, void *descr) { return GC_MALLOC (size); } void mono_gc_free_fixed (void* addr) { } int mono_gc_invoke_finalizers (void) { /* There is a bug in GC_invoke_finalizer () in versions <= 6.2alpha4: * the 'mem_freed' variable is not initialized when there are no * objects to finalize, which leads to strange behavior later on. * The check is necessary to work around that bug. */ if (GC_should_invoke_finalizers ()) return GC_invoke_finalizers (); return 0; } gboolean mono_gc_pending_finalizers (void) { return GC_should_invoke_finalizers (); } void mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value) { *(void**)field_ptr = value; } void mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value) { *(void**)slot_ptr = value; } void mono_gc_wbarrier_arrayref_copy (MonoArray *arr, gpointer slot_ptr, int count) { /* no need to do anything */ } void mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value) { *(void**)ptr = value; } void mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass) { } void mono_gc_wbarrier_object (MonoObject *object) { } #if defined(USE_INCLUDED_LIBGC) && defined(USE_COMPILER_TLS) && defined(__linux__) && (defined(__i386__) || defined(__x86_64__)) extern __thread MONO_TLS_FAST void* GC_thread_tls; #include "metadata-internals.h" static int shift_amount (int v) { int i = 0; while (!(v & (1 << i))) i++; return i; } enum { ATYPE_FREEPTR, ATYPE_FREEPTR_FOR_BOX, ATYPE_NORMAL, ATYPE_GCJ, ATYPE_STRING, ATYPE_NUM }; static MonoMethod* create_allocator (int atype, int offset) { int index_var, bytes_var, my_fl_var, my_entry_var; guint32 no_freelist_branch, not_small_enough_branch = 0; guint32 size_overflow_branch = 0; MonoMethodBuilder *mb; MonoMethod *res; MonoMethodSignature *csig; if (atype == ATYPE_STRING) { csig = mono_metadata_signature_alloc (mono_defaults.corlib, 2); csig->ret = &mono_defaults.string_class->byval_arg; csig->params [0] = &mono_defaults.int_class->byval_arg; csig->params [1] = &mono_defaults.int32_class->byval_arg; } else { csig = mono_metadata_signature_alloc (mono_defaults.corlib, 1); csig->ret = &mono_defaults.object_class->byval_arg; csig->params [0] = &mono_defaults.int_class->byval_arg; } mb = mono_mb_new (mono_defaults.object_class, "Alloc", MONO_WRAPPER_ALLOC); bytes_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg); if (atype == ATYPE_STRING) { /* a string alloator method takes the args: (vtable, len) */ /* bytes = (sizeof (MonoString) + ((len + 1) * 2)); */ mono_mb_emit_ldarg (mb, 1); mono_mb_emit_icon (mb, 1); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_icon (mb, 1); mono_mb_emit_byte (mb, MONO_CEE_SHL); // sizeof (MonoString) might include padding mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, chars)); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_stloc (mb, bytes_var); } else { /* bytes = vtable->klass->instance_size */ mono_mb_emit_ldarg (mb, 0); mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass)); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_byte (mb, MONO_CEE_LDIND_I); mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, instance_size)); mono_mb_emit_byte (mb, MONO_CEE_ADD); /* FIXME: assert instance_size stays a 4 byte integer */ mono_mb_emit_byte (mb, MONO_CEE_LDIND_U4); mono_mb_emit_stloc (mb, bytes_var); } /* this is needed for strings/arrays only as the other big types are never allocated with this method */ if (atype == ATYPE_STRING) { /* check for size */ /* if (!SMALL_ENOUGH (bytes)) jump slow_path;*/ mono_mb_emit_ldloc (mb, bytes_var); mono_mb_emit_icon (mb, (NFREELISTS-1) * GRANULARITY); not_small_enough_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S); /* check for overflow */ mono_mb_emit_ldloc (mb, bytes_var); mono_mb_emit_icon (mb, sizeof (MonoString)); size_overflow_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLE_UN_S); } /* int index = INDEX_FROM_BYTES(bytes); */ index_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg); mono_mb_emit_ldloc (mb, bytes_var); mono_mb_emit_icon (mb, GRANULARITY - 1); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_icon (mb, shift_amount (GRANULARITY)); mono_mb_emit_byte (mb, MONO_CEE_SHR_UN); mono_mb_emit_icon (mb, shift_amount (sizeof (gpointer))); mono_mb_emit_byte (mb, MONO_CEE_SHL); /* index var is already adjusted into bytes */ mono_mb_emit_stloc (mb, index_var); my_fl_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg); my_entry_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg); /* my_fl = ((GC_thread)tsd) -> ptrfree_freelists + index; */ mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX); mono_mb_emit_byte (mb, 0x0D); /* CEE_MONO_TLS */ mono_mb_emit_i4 (mb, offset); if (atype == ATYPE_FREEPTR || atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING) mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, ptrfree_freelists)); else if (atype == ATYPE_NORMAL) mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, normal_freelists)); else if (atype == ATYPE_GCJ) mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, gcj_freelists)); else g_assert_not_reached (); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_ldloc (mb, index_var); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_stloc (mb, my_fl_var); /* my_entry = *my_fl; */ mono_mb_emit_ldloc (mb, my_fl_var); mono_mb_emit_byte (mb, MONO_CEE_LDIND_I); mono_mb_emit_stloc (mb, my_entry_var); /* if (EXPECT((word)my_entry >= HBLKSIZE, 1)) { */ mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_icon (mb, HBLKSIZE); no_freelist_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S); /* ptr_t next = obj_link(my_entry); *my_fl = next; */ mono_mb_emit_ldloc (mb, my_fl_var); mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_byte (mb, MONO_CEE_LDIND_I); mono_mb_emit_byte (mb, MONO_CEE_STIND_I); /* set the vtable and clear the words in the object */ mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_ldarg (mb, 0); mono_mb_emit_byte (mb, MONO_CEE_STIND_I); if (atype == ATYPE_FREEPTR) { int start_var, end_var, start_loop; /* end = my_entry + bytes; start = my_entry + sizeof (gpointer); */ start_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg); end_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg); mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_ldloc (mb, bytes_var); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_stloc (mb, end_var); mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation)); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_stloc (mb, start_var); /* * do { * *start++ = NULL; * } while (start < end); */ start_loop = mono_mb_get_label (mb); mono_mb_emit_ldloc (mb, start_var); mono_mb_emit_icon (mb, 0); mono_mb_emit_byte (mb, MONO_CEE_STIND_I); mono_mb_emit_ldloc (mb, start_var); mono_mb_emit_icon (mb, sizeof (gpointer)); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_stloc (mb, start_var); mono_mb_emit_ldloc (mb, start_var); mono_mb_emit_ldloc (mb, end_var); mono_mb_emit_byte (mb, MONO_CEE_BLT_UN_S); mono_mb_emit_byte (mb, start_loop - (mono_mb_get_label (mb) + 1)); } else if (atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING) { /* need to clear just the sync pointer */ mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation)); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_icon (mb, 0); mono_mb_emit_byte (mb, MONO_CEE_STIND_I); } if (atype == ATYPE_STRING) { /* need to set length and clear the last char */ /* s->length = len; */ mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, length)); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_ldarg (mb, 1); mono_mb_emit_byte (mb, MONO_CEE_STIND_I4); /* s->chars [len] = 0; */ mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_ldloc (mb, bytes_var); mono_mb_emit_icon (mb, 2); mono_mb_emit_byte (mb, MONO_CEE_SUB); mono_mb_emit_byte (mb, MONO_CEE_ADD); mono_mb_emit_icon (mb, 0); mono_mb_emit_byte (mb, MONO_CEE_STIND_I2); } /* return my_entry; */ mono_mb_emit_ldloc (mb, my_entry_var); mono_mb_emit_byte (mb, MONO_CEE_RET); mono_mb_patch_short_branch (mb, no_freelist_branch); if (not_small_enough_branch > 0) mono_mb_patch_short_branch (mb, not_small_enough_branch); if (size_overflow_branch > 0) mono_mb_patch_short_branch (mb, size_overflow_branch); /* the slow path: we just call back into the runtime */ if (atype == ATYPE_STRING) { mono_mb_emit_ldarg (mb, 1); mono_mb_emit_icall (mb, mono_string_alloc); } else { mono_mb_emit_ldarg (mb, 0); mono_mb_emit_icall (mb, mono_object_new_specific); } mono_mb_emit_byte (mb, MONO_CEE_RET); res = mono_mb_create_method (mb, csig, 8); mono_mb_free (mb); mono_method_get_header (res)->init_locals = FALSE; return res; } static MonoMethod* alloc_method_cache [ATYPE_NUM]; /* * If possible, generate a managed method that can quickly allocate objects in class * @klass. The method will typically have an thread-local inline allocation sequence. * The signature of the called method is: * object allocate (MonoVTable *vtable) * Some of the logic here is similar to mono_class_get_allocation_ftn () i object.c, * keep in sync. * The thread local alloc logic is taken from libgc/pthread_support.c. */ MonoMethod* mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box) { int offset = -1; int atype; MonoClass *klass = vtable->klass; MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset); /*g_print ("thread tls: %d\n", offset);*/ if (offset == -1) return NULL; if (!SMALL_ENOUGH (klass->instance_size)) return NULL; if (klass->has_finalize || klass->marshalbyref || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS)) return NULL; if (klass->rank) return NULL; if (klass->byval_arg.type == MONO_TYPE_STRING) { atype = ATYPE_STRING; } else if (!klass->has_references) { if (for_box) atype = ATYPE_FREEPTR_FOR_BOX; else atype = ATYPE_FREEPTR; } else { return NULL; /* * disabled because we currently do a runtime choice anyway, to * deal with multiple appdomains. if (vtable->gc_descr != GC_NO_DESCRIPTOR) atype = ATYPE_GCJ; else atype = ATYPE_NORMAL; */ } return mono_gc_get_managed_allocator_by_type (atype); } /** * mono_gc_get_managed_allocator_id: * * Return a type for the managed allocator method MANAGED_ALLOC which can later be passed * to mono_gc_get_managed_allocator_by_type () to get back this allocator method. This can be * used by the AOT code to encode references to managed allocator methods. */ int mono_gc_get_managed_allocator_type (MonoMethod *managed_alloc) { int i; mono_loader_lock (); for (i = 0; i < ATYPE_NUM; ++i) { if (alloc_method_cache [i] == managed_alloc) { mono_loader_unlock (); return i; } } mono_loader_unlock (); return -1; } /** * mono_gc_get_managed_allocator_by_type: * * Return a managed allocator method corresponding to allocator type ATYPE. */ MonoMethod* mono_gc_get_managed_allocator_by_type (int atype) { int offset = -1; MonoMethod *res; MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset); mono_loader_lock (); res = alloc_method_cache [atype]; if (!res) res = alloc_method_cache [atype] = create_allocator (atype, offset); mono_loader_unlock (); return res; } #else MonoMethod* mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box) { return NULL; } int mono_gc_get_managed_allocator_type (MonoMethod *managed_alloc) { return -1; } MonoMethod* mono_gc_get_managed_allocator_by_type (int atype) { return NULL; } #endif #endif /* no Boehm GC */