#ifdef HAVE_SGEN_GC
#include <stdlib.h>
+#include <errno.h>
#include "sgen-gc.h"
#include "sgen-bridge.h"
#include "sgen-hash-table.h"
#include "sgen-qsort.h"
+#include "tabledefs.h"
#include "utils/mono-logger-internal.h"
#include "utils/mono-time.h"
#include "utils/mono-compiler.h"
+//#define NEW_XREFS
+#ifdef NEW_XREFS
+//#define TEST_NEW_XREFS
+#endif
+
+#if !defined(NEW_XREFS) || defined(TEST_NEW_XREFS)
+#define OLD_XREFS
+#endif
+
+#ifdef NEW_XREFS
+#define XREFS new_xrefs
+#else
+#define XREFS old_xrefs
+#endif
+
+#define OPTIMIZATION_COPY
+#define OPTIMIZATION_FORWARD
+#define OPTIMIZATION_SINGLETON_DYN_ARRAY
typedef struct {
int size;
- int capacity;
+ int capacity; /* if negative, data points to another DynArray's data */
char *data;
} DynArray;
* just one source, so use the srcs pointer itself.
*/
typedef struct _HashEntry {
- MonoObject *obj; /* This is a duplicate - it's already stored in the hash table */
-
gboolean is_bridge;
- gboolean is_visited;
- int finishing_time;
+ union {
+ struct {
+ guint32 is_visited : 1;
+ guint32 finishing_time : 31;
+ struct _HashEntry *forwarded_to;
+ } dfs1;
+ struct {
+ int scc_index;
+ } dfs2;
+ } v;
DynPtrArray srcs;
-
- int scc_index;
} HashEntry;
typedef struct {
int index;
int api_index;
int num_bridge_entries;
- DynIntArray xrefs; /* these are incoming, not outgoing */
+ gboolean flag;
+ /*
+ * New and old xrefs are typically mutually exclusive. Only when TEST_NEW_XREFS is
+ * enabled we do both, and compare the results. This should only be done for
+ * debugging, obviously.
+ */
+#ifdef OLD_XREFS
+ DynIntArray old_xrefs; /* these are incoming, not outgoing */
+#endif
+#ifdef NEW_XREFS
+ DynIntArray new_xrefs;
+#endif
} SCC;
static SgenHashTable hash_table = SGEN_HASH_TABLE_INIT (INTERNAL_MEM_BRIDGE_HASH_TABLE, INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY, sizeof (HashEntry), mono_aligned_addr_hash, NULL);
-static int current_time;
+static guint32 current_time;
static gboolean bridge_accounting_enabled = FALSE;
+static SgenBridgeProcessor *bridge_processor;
/* Core functions */
/* public */
static void
dyn_array_uninit (DynArray *da, int elem_size)
{
- if (da->capacity <= 0)
+ if (da->capacity < 0) {
+ dyn_array_init (da);
+ return;
+ }
+
+ if (da->capacity == 0)
return;
sgen_free_internal_dynamic (da->data, elem_size * da->capacity, INTERNAL_MEM_BRIDGE_DATA);
da->data = NULL;
}
+static void
+dyn_array_empty (DynArray *da)
+{
+ if (da->capacity < 0)
+ dyn_array_init (da);
+ else
+ da->size = 0;
+}
+
static void
dyn_array_ensure_capacity (DynArray *da, int capacity, int elem_size)
{
int old_capacity = da->capacity;
char *new_data;
+ g_assert (capacity > 0);
+
if (capacity <= old_capacity)
return;
- if (da->capacity == 0)
+ if (old_capacity <= 0)
da->capacity = 2;
while (capacity > da->capacity)
da->capacity *= 2;
new_data = sgen_alloc_internal_dynamic (elem_size * da->capacity, INTERNAL_MEM_BRIDGE_DATA, TRUE);
memcpy (new_data, da->data, elem_size * da->size);
- sgen_free_internal_dynamic (da->data, elem_size * old_capacity, INTERNAL_MEM_BRIDGE_DATA);
+ if (old_capacity > 0)
+ sgen_free_internal_dynamic (da->data, elem_size * old_capacity, INTERNAL_MEM_BRIDGE_DATA);
da->data = new_data;
}
+static gboolean
+dyn_array_is_copy (DynArray *da)
+{
+ return da->capacity < 0;
+}
+
+static void
+dyn_array_ensure_independent (DynArray *da, int elem_size)
+{
+ if (!dyn_array_is_copy (da))
+ return;
+ dyn_array_ensure_capacity (da, da->size, elem_size);
+ g_assert (da->capacity > 0);
+}
+
static void*
dyn_array_add (DynArray *da, int elem_size)
{
return p;
}
+static void
+dyn_array_copy (DynArray *dst, DynArray *src, int elem_size)
+{
+ dyn_array_uninit (dst, elem_size);
+
+ if (src->size == 0)
+ return;
+
+ dst->size = src->size;
+ dst->capacity = -1;
+ dst->data = src->data;
+}
+
/* int */
static void
dyn_array_int_init (DynIntArray *da)
return da->array.size;
}
+#ifdef NEW_XREFS
static void
-dyn_array_int_set_size (DynIntArray *da, int size)
+dyn_array_int_empty (DynIntArray *da)
{
- da->array.size = size;
+ dyn_array_empty (&da->array);
}
+#endif
static void
dyn_array_int_add (DynIntArray *da, int x)
return ((int*)da->array.data)[x];
}
+#ifdef NEW_XREFS
static void
dyn_array_int_set (DynIntArray *da, int idx, int val)
{
((int*)da->array.data)[idx] = val;
}
+#endif
static void
-dyn_array_int_ensure_capacity (DynIntArray *da, int capacity)
+dyn_array_int_ensure_independent (DynIntArray *da)
{
- dyn_array_ensure_capacity (&da->array, capacity, sizeof (int));
+ dyn_array_ensure_independent (&da->array, sizeof (int));
}
static void
-dyn_array_int_set_all (DynIntArray *dst, DynIntArray *src)
+dyn_array_int_copy (DynIntArray *dst, DynIntArray *src)
+{
+ dyn_array_copy (&dst->array, &src->array, sizeof (int));
+}
+
+static gboolean
+dyn_array_int_is_copy (DynIntArray *da)
{
- dyn_array_int_ensure_capacity (dst, src->array.size);
- memcpy (dst->array.data, src->array.data, src->array.size * sizeof (int));
- dst->array.size = src->array.size;
+ return dyn_array_is_copy (&da->array);
}
/* ptr */
static void
dyn_array_ptr_uninit (DynPtrArray *da)
{
- dyn_array_uninit (&da->array, sizeof (void*));
+#ifdef OPTIMIZATION_SINGLETON_DYN_ARRAY
+ if (da->array.capacity == 1)
+ dyn_array_ptr_init (da);
+ else
+#endif
+ dyn_array_uninit (&da->array, sizeof (void*));
}
static int
}
static void
-dyn_array_ptr_set_size (DynPtrArray *da, int size)
+dyn_array_ptr_empty (DynPtrArray *da)
{
- da->array.size = size;
+#ifdef OPTIMIZATION_SINGLETON_DYN_ARRAY
+ if (da->array.capacity == 1)
+ dyn_array_ptr_init (da);
+ else
+#endif
+ dyn_array_empty (&da->array);
}
static void*
dyn_array_ptr_get (DynPtrArray *da, int x)
{
+#ifdef OPTIMIZATION_SINGLETON_DYN_ARRAY
+ if (da->array.capacity == 1) {
+ g_assert (x == 0);
+ return da->array.data;
+ }
+#endif
return ((void**)da->array.data)[x];
}
static void
dyn_array_ptr_add (DynPtrArray *da, void *ptr)
{
- void **p = dyn_array_add (&da->array, sizeof (void*));
+ void **p;
+
+#ifdef OPTIMIZATION_SINGLETON_DYN_ARRAY
+ if (da->array.capacity == 0) {
+ da->array.capacity = 1;
+ da->array.size = 1;
+ p = (void**)&da->array.data;
+ } else if (da->array.capacity == 1) {
+ void *ptr0 = da->array.data;
+ void **p0;
+ dyn_array_init (&da->array);
+ p0 = dyn_array_add (&da->array, sizeof (void*));
+ *p0 = ptr0;
+ p = dyn_array_add (&da->array, sizeof (void*));
+ } else
+#endif
+ {
+ p = dyn_array_add (&da->array, sizeof (void*));
+ }
*p = ptr;
}
static void*
dyn_array_ptr_pop (DynPtrArray *da)
{
- void *p;
int size = da->array.size;
+ void *p;
g_assert (size > 0);
- p = dyn_array_ptr_get (da, size - 1);
- --da->array.size;
+#ifdef OPTIMIZATION_SINGLETON_DYN_ARRAY
+ if (da->array.capacity == 1) {
+ p = dyn_array_ptr_get (da, 0);
+ dyn_array_init (&da->array);
+ } else
+#endif
+ {
+ g_assert (da->array.capacity > 1);
+ dyn_array_ensure_independent (&da->array, sizeof (void*));
+ p = dyn_array_ptr_get (da, size - 1);
+ --da->array.size;
+ }
return p;
}
static DynIntArray merge_array;
+#ifdef NEW_XREFS
static gboolean
dyn_array_int_contains (DynIntArray *da, int x)
{
return TRUE;
return FALSE;
}
-
+#endif
static void
-dyn_array_int_merge (DynIntArray *dst, DynIntArray *src)
+enable_accounting (void)
{
- int i, j;
-
- dyn_array_int_ensure_capacity (&merge_array, dyn_array_int_size (dst) + dyn_array_int_size (src));
- dyn_array_int_set_size (&merge_array, 0);
-
- for (i = j = 0; i < dyn_array_int_size (dst) || j < dyn_array_int_size (src); ) {
- if (i < dyn_array_int_size (dst) && j < dyn_array_int_size (src)) {
- int a = dyn_array_int_get (dst, i);
- int b = dyn_array_int_get (src, j);
- if (a < b) {
- dyn_array_int_add (&merge_array, a);
- ++i;
- } else if (a == b) {
- dyn_array_int_add (&merge_array, a);
- ++i;
- ++j;
- } else {
- dyn_array_int_add (&merge_array, b);
- ++j;
- }
- } else if (i < dyn_array_int_size (dst)) {
- dyn_array_int_add (&merge_array, dyn_array_int_get (dst, i));
- ++i;
- } else {
- dyn_array_int_add (&merge_array, dyn_array_int_get (src, j));
- ++j;
- }
- }
-
- if (dyn_array_int_size (&merge_array) > dyn_array_int_size (dst)) {
- dyn_array_int_set_all (dst, &merge_array);
- }
+ SgenHashTable table = SGEN_HASH_TABLE_INIT (INTERNAL_MEM_BRIDGE_HASH_TABLE, INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY, sizeof (HashEntryWithAccounting), mono_aligned_addr_hash, NULL);
+ bridge_accounting_enabled = TRUE;
+ hash_table = table;
}
-static void
-dyn_array_int_merge_one (DynIntArray *array, int value)
+static MonoGCBridgeObjectKind
+class_kind (MonoClass *class)
{
- int i;
- int tmp;
- int size = dyn_array_int_size (array);
+ MonoGCBridgeObjectKind res = bridge_callbacks.bridge_class_kind (class);
- for (i = 0; i < size; ++i) {
- if (dyn_array_int_get (array, i) == value)
- return;
- else if (dyn_array_int_get (array, i) > value)
- break;
+ /* If it's a bridge, nothing we can do about it. */
+ if (res == GC_BRIDGE_TRANSPARENT_BRIDGE_CLASS || res == GC_BRIDGE_OPAQUE_BRIDGE_CLASS)
+ return res;
+
+ /* Non bridge classes with no pointers will never point to a bridge, so we can savely ignore them. */
+ if (!class->has_references) {
+ SGEN_LOG (6, "class %s is opaque\n", class->name);
+ return GC_BRIDGE_OPAQUE_CLASS;
}
- dyn_array_int_ensure_capacity (array, size + 1);
+ /* Some arrays can be ignored */
+ if (class->rank == 1) {
+ MonoClass *elem_class = class->element_class;
- if (i < size) {
- tmp = dyn_array_int_get (array, i);
- for (; i < size; ++i) {
- dyn_array_int_set (array, i, value);
- value = tmp;
- tmp = dyn_array_int_get (array, i + 1);
+ /* FIXME the bridge check can be quite expensive, cache it at the class level. */
+ /* An array of a sealed type that is not a bridge will never get to a bridge */
+ if ((elem_class->flags & TYPE_ATTRIBUTE_SEALED) && !elem_class->has_references && !bridge_callbacks.bridge_class_kind (elem_class)) {
+ SGEN_LOG (6, "class %s is opaque\n", class->name);
+ return GC_BRIDGE_OPAQUE_CLASS;
}
- dyn_array_int_set (array, size, value);
- } else {
- dyn_array_int_set (array, size, value);
}
- dyn_array_int_set_size (array, size + 1);
-}
-
-
-static void
-enable_accounting (void)
-{
- bridge_accounting_enabled = TRUE;
- hash_table = (SgenHashTable)SGEN_HASH_TABLE_INIT (INTERNAL_MEM_BRIDGE_HASH_TABLE, INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY, sizeof (HashEntryWithAccounting), mono_aligned_addr_hash, NULL);
-}
-
-static MonoGCBridgeObjectKind
-class_kind (MonoClass *class)
-{
- return bridge_callbacks.bridge_class_kind (class);
+ return GC_BRIDGE_TRANSPARENT_CLASS;
}
static HashEntry*
memset (&new_entry, 0, sizeof (HashEntry));
- new_entry.obj = obj;
dyn_array_ptr_init (&new_entry.srcs);
- new_entry.finishing_time = -1;
- new_entry.scc_index = -1;
+ new_entry.v.dfs1.finishing_time = 0;
sgen_hash_table_replace (&hash_table, obj, &new_entry, NULL);
}
static void
-register_finishing_time (HashEntry *entry, int t)
+register_finishing_time (HashEntry *entry, guint32 t)
{
- g_assert (entry->finishing_time < 0);
- entry->finishing_time = t;
+ g_assert (entry->v.dfs1.finishing_time == 0);
+ /* finishing_time has 31 bits, so it must be within signed int32 range. */
+ g_assert (t > 0 && t <= G_MAXINT32);
+ entry->v.dfs1.finishing_time = t;
}
+static int ignored_objects;
+
static gboolean
-object_is_live (MonoObject **objp)
+is_opaque_object (MonoObject *obj)
+{
+ if ((obj->vtable->gc_bits & SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT) == SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT) {
+ SGEN_LOG (6, "ignoring %s\n", obj->vtable->klass->name);
+ ++ignored_objects;
+ return TRUE;
+ }
+ return FALSE;
+}
+
+static gboolean
+object_needs_expansion (MonoObject **objp)
{
MonoObject *obj = *objp;
MonoObject *fwd = SGEN_OBJECT_IS_FORWARDED (obj);
if (fwd) {
*objp = fwd;
- return sgen_hash_table_lookup (&hash_table, fwd) == NULL;
+ if (is_opaque_object (fwd))
+ return FALSE;
+ return sgen_hash_table_lookup (&hash_table, fwd) != NULL;
}
- if (!sgen_object_is_live (obj))
+ if (is_opaque_object (obj))
return FALSE;
- return sgen_hash_table_lookup (&hash_table, obj) == NULL;
+ if (!sgen_object_is_live (obj))
+ return TRUE;
+ return sgen_hash_table_lookup (&hash_table, obj) != NULL;
+}
+
+static HashEntry*
+follow_forward (HashEntry *entry)
+{
+#ifdef OPTIMIZATION_FORWARD
+ while (entry->v.dfs1.forwarded_to) {
+ HashEntry *next = entry->v.dfs1.forwarded_to;
+ if (next->v.dfs1.forwarded_to)
+ entry->v.dfs1.forwarded_to = next->v.dfs1.forwarded_to;
+ entry = next;
+ }
+#else
+ g_assert (!entry->v.dfs1.forwarded_to);
+#endif
+ return entry;
}
static DynPtrArray registered_bridges;
static int dfs1_passes, dfs2_passes;
+/*
+ * DFS1 maintains a stack, where each two entries are effectively one entry. (FIXME:
+ * Optimize this via pointer tagging.) There are two different types of entries:
+ *
+ * entry, src: entry needs to be expanded via scanning, and linked to from src
+ * NULL, entry: entry has already been expanded and needs to be finished
+ */
#undef HANDLE_PTR
#define HANDLE_PTR(ptr,obj) do { \
MonoObject *dst = (MonoObject*)*(ptr); \
- if (dst && !object_is_live (&dst)) { \
+ if (dst && object_needs_expansion (&dst)) { \
+ ++num_links; \
dyn_array_ptr_push (&dfs_stack, obj_entry); \
- dyn_array_ptr_push (&dfs_stack, get_hash_entry (dst, NULL)); \
+ dyn_array_ptr_push (&dfs_stack, follow_forward (get_hash_entry (dst, NULL))); \
} \
} while (0)
obj_entry = dyn_array_ptr_pop (&dfs_stack);
if (obj_entry) {
+ /* obj_entry needs to be expanded */
src = dyn_array_ptr_pop (&dfs_stack);
- obj = obj_entry->obj;
+ if (src)
+ g_assert (!src->v.dfs1.forwarded_to);
+
+ obj_entry = follow_forward (obj_entry);
+
+ again:
+ g_assert (!obj_entry->v.dfs1.forwarded_to);
+ obj = sgen_hash_table_key_for_value_pointer (obj_entry);
start = (char*)obj;
+ if (!obj_entry->v.dfs1.is_visited) {
+ int num_links = 0;
+ mword desc = sgen_obj_get_descriptor (start);
+
+ obj_entry->v.dfs1.is_visited = 1;
+
+ /* push the finishing entry on the stack */
+ dyn_array_ptr_push (&dfs_stack, obj_entry);
+ dyn_array_ptr_push (&dfs_stack, NULL);
+
+#include "sgen-scan-object.h"
+
+ /*
+ * We can remove non-bridge objects with a single outgoing
+ * link by forwarding links going to it.
+ *
+ * This is the first time we've encountered this object, so
+ * no links to it have yet been added. We'll keep it that
+ * way by setting the forward pointer, and instead of
+ * continuing processing this object, we start over with the
+ * object it points to.
+ */
+#ifdef OPTIMIZATION_FORWARD
+ if (!obj_entry->is_bridge && num_links == 1) {
+ HashEntry *dst_entry = dyn_array_ptr_pop (&dfs_stack);
+ HashEntry *obj_entry_again = dyn_array_ptr_pop (&dfs_stack);
+ g_assert (obj_entry_again == obj_entry);
+ g_assert (!dst_entry->v.dfs1.forwarded_to);
+ if (obj_entry != dst_entry) {
+ obj_entry->v.dfs1.forwarded_to = dst_entry;
+ obj_entry = dst_entry;
+ }
+ goto again;
+ }
+#endif
+ }
+
if (src) {
//g_print ("link %s -> %s\n", sgen_safe_name (src->obj), sgen_safe_name (obj));
+ g_assert (!obj_entry->v.dfs1.forwarded_to);
add_source (obj_entry, src);
} else {
//g_print ("starting with %s\n", sgen_safe_name (obj));
}
-
- if (obj_entry->is_visited)
- continue;
-
- obj_entry->is_visited = TRUE;
-
- dyn_array_ptr_push (&dfs_stack, obj_entry);
- /* NULL marks that the next entry is to be finished */
- dyn_array_ptr_push (&dfs_stack, NULL);
-
-#include "sgen-scan-object.h"
} else {
+ /* obj_entry needs to be finished */
+
obj_entry = dyn_array_ptr_pop (&dfs_stack);
//g_print ("finish %s\n", sgen_safe_name (obj_entry->obj));
- register_finishing_time (obj_entry, current_time++);
+ register_finishing_time (obj_entry, ++current_time);
}
} while (dyn_array_ptr_size (&dfs_stack) > 0);
}
+static DynSCCArray sccs;
+static SCC *current_scc;
+
+/*
+ * At the end of bridge processing we need to end up with an (acyclyc) graph of bridge
+ * object SCCs, where the links between the nodes (each one an SCC) in that graph represent
+ * the presence of a direct or indirect link between those SCCs. An example:
+ *
+ * D
+ * |
+ * v
+ * A -> B -> c -> e -> F
+ *
+ * A, B, D and F are SCCs that contain bridge objects, c and e don't contain bridge objects.
+ * The graph we need to produce from this is:
+ *
+ * D
+ * |
+ * v
+ * A -> B -> F
+ *
+ * Note that we don't need to produce an edge from A to F. It's sufficient that F is
+ * indirectly reachable from A.
+ *
+ * The old algorithm would create a set, for each SCC, of bridge SCCs that can reach it,
+ * directly or indirectly, by merging the ones sets for those that reach it directly. The
+ * sets it would build up are these:
+ *
+ * A: {}
+ * B: {A}
+ * c: {B}
+ * D: {}
+ * e: {B,D}
+ * F: {B,D}
+ *
+ * The merge operations on these sets turned out to be huge time sinks.
+ *
+ * The new algorithm proceeds in two passes: During DFS2, it only builds up the sets of SCCs
+ * that directly point to each SCC:
+ *
+ * A: {}
+ * B: {A}
+ * c: {B}
+ * D: {}
+ * e: {c,D}
+ * F: {e}
+ *
+ * This is the adjacency list for the SCC graph, in other words. In a separate step
+ * afterwards, it does a depth-first traversal of that graph, for each bridge node, to get
+ * to the final list. It uses a flag to avoid traversing any node twice.
+ */
static void
scc_add_xref (SCC *src, SCC *dst)
{
g_assert (src != dst);
g_assert (src->index != dst->index);
- if (dyn_array_int_contains (&dst->xrefs, src->index))
- return;
+#ifdef NEW_XREFS
+ /*
+ * FIXME: Right now we don't even unique the direct ancestors, but just add to the
+ * list. Doing a containment check slows this algorithm down to almost the speed of
+ * the old one. Use the flag instead!
+ */
+ dyn_array_int_add (&dst->new_xrefs, src->index);
+#endif
+
+#ifdef OLD_XREFS
+ if (dyn_array_int_is_copy (&dst->old_xrefs)) {
+ int i;
+ dyn_array_int_ensure_independent (&dst->old_xrefs);
+ for (i = 0; i < dyn_array_int_size (&dst->old_xrefs); ++i) {
+ int j = dyn_array_int_get (&dst->old_xrefs, i);
+ SCC *bridge_scc = dyn_array_scc_get_ptr (&sccs, j);
+ g_assert (!bridge_scc->flag);
+ bridge_scc->flag = TRUE;
+ }
+ }
+
if (src->num_bridge_entries) {
- dyn_array_int_merge_one (&dst->xrefs, src->index);
+ if (src->flag)
+ return;
+ src->flag = TRUE;
+ dyn_array_int_add (&dst->old_xrefs, src->index);
+#ifdef OPTIMIZATION_COPY
+ } else if (dyn_array_int_size (&dst->old_xrefs) == 0) {
+ dyn_array_int_copy (&dst->old_xrefs, &src->old_xrefs);
+#endif
} else {
int i;
- dyn_array_int_merge (&dst->xrefs, &src->xrefs);
- for (i = 0; i < dyn_array_int_size (&dst->xrefs); ++i)
- g_assert (dyn_array_int_get (&dst->xrefs, i) != dst->index);
+ for (i = 0; i < dyn_array_int_size (&src->old_xrefs); ++i) {
+ int j = dyn_array_int_get (&src->old_xrefs, i);
+ SCC *bridge_scc = dyn_array_scc_get_ptr (&sccs, j);
+ g_assert (bridge_scc->num_bridge_entries);
+ if (!bridge_scc->flag) {
+ bridge_scc->flag = TRUE;
+ dyn_array_int_add (&dst->old_xrefs, j);
+ }
+ }
}
+#endif
}
static void
scc_add_entry (SCC *scc, HashEntry *entry)
{
- g_assert (entry->scc_index < 0);
- entry->scc_index = scc->index;
+ g_assert (entry->v.dfs2.scc_index < 0);
+ entry->v.dfs2.scc_index = scc->index;
if (entry->is_bridge)
++scc->num_bridge_entries;
}
-static DynSCCArray sccs;
-static SCC *current_scc;
-
static void
dfs2 (HashEntry *entry)
{
entry = dyn_array_ptr_pop (&dfs_stack);
++dfs2_passes;
- if (entry->scc_index >= 0) {
- if (entry->scc_index != current_scc->index)
- scc_add_xref (dyn_array_scc_get_ptr (&sccs, entry->scc_index), current_scc);
+ if (entry->v.dfs2.scc_index >= 0) {
+ if (entry->v.dfs2.scc_index != current_scc->index)
+ scc_add_xref (dyn_array_scc_get_ptr (&sccs, entry->v.dfs2.scc_index), current_scc);
continue;
}
for (i = 0; i < dyn_array_ptr_size (&entry->srcs); ++i)
dyn_array_ptr_push (&dfs_stack, dyn_array_ptr_get (&entry->srcs, i));
} while (dyn_array_ptr_size (&dfs_stack) > 0);
+
+#ifdef OLD_XREFS
+ /* If xrefs is a copy then we haven't set a single flag. */
+ if (dyn_array_int_is_copy (¤t_scc->old_xrefs))
+ return;
+ for (i = 0; i < dyn_array_int_size (¤t_scc->old_xrefs); ++i) {
+ int j = dyn_array_int_get (¤t_scc->old_xrefs, i);
+ SCC *bridge_scc = dyn_array_scc_get_ptr (&sccs, j);
+ g_assert (bridge_scc->flag);
+ bridge_scc->flag = FALSE;
+ }
+#endif
+}
+
+#ifdef NEW_XREFS
+static void
+gather_xrefs (SCC *scc)
+{
+ int i;
+ for (i = 0; i < dyn_array_int_size (&scc->new_xrefs); ++i) {
+ int index = dyn_array_int_get (&scc->new_xrefs, i);
+ SCC *src = dyn_array_scc_get_ptr (&sccs, index);
+ if (src->flag)
+ continue;
+ src->flag = TRUE;
+ if (src->num_bridge_entries)
+ dyn_array_int_add (&merge_array, index);
+ else
+ gather_xrefs (src);
+ }
+}
+
+static void
+reset_flags (SCC *scc)
+{
+ int i;
+ for (i = 0; i < dyn_array_int_size (&scc->new_xrefs); ++i) {
+ int index = dyn_array_int_get (&scc->new_xrefs, i);
+ SCC *src = dyn_array_scc_get_ptr (&sccs, index);
+ if (!src->flag)
+ continue;
+ src->flag = FALSE;
+ if (!src->num_bridge_entries)
+ reset_flags (src);
+ }
+}
+#endif
+
+static char *dump_prefix = NULL;
+
+static void
+dump_graph (void)
+{
+ static int counter = 0;
+
+ MonoObject *obj;
+ HashEntry *entry;
+ size_t prefix_len = strlen (dump_prefix);
+ char *filename = alloca(prefix_len + 64);
+ FILE *file;
+ int edge_id = 0;
+
+ sprintf (filename, "%s.%d.gexf", dump_prefix, counter++);
+ file = fopen (filename, "w");
+
+ if (file == NULL) {
+ fprintf (stderr, "Warning: Could not open bridge dump file `%s` for writing: %s\n", filename, strerror (errno));
+ return;
+ }
+
+ fprintf (file, "<gexf xmlns=\"http://www.gexf.net/1.2draft\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://www.gexf.net/1.2draft http://www.gexf.net/1.2draft/gexf.xsd\" version=\"1.2\">\n");
+
+ fprintf (file, "<graph defaultedgetype=\"directed\">\n"
+ "<attributes class=\"node\">\n"
+ "<attribute id=\"0\" title=\"class\" type=\"string\"/>\n"
+ "<attribute id=\"1\" title=\"bridge\" type=\"boolean\"/>\n"
+ "</attributes>\n");
+
+ fprintf (file, "<nodes>\n");
+ SGEN_HASH_TABLE_FOREACH (&hash_table, obj, entry) {
+ MonoVTable *vt = (MonoVTable*) SGEN_LOAD_VTABLE (obj);
+ fprintf (file, "<node id=\"%p\"><attvalues><attvalue for=\"0\" value=\"%s.%s\"/><attvalue for=\"1\" value=\"%s\"/></attvalues></node>\n",
+ obj, vt->klass->name_space, vt->klass->name, entry->is_bridge ? "true" : "false");
+ } SGEN_HASH_TABLE_FOREACH_END;
+ fprintf (file, "</nodes>\n");
+
+ fprintf (file, "<edges>\n");
+ SGEN_HASH_TABLE_FOREACH (&hash_table, obj, entry) {
+ int i;
+ for (i = 0; i < dyn_array_ptr_size (&entry->srcs); ++i) {
+ HashEntry *src = dyn_array_ptr_get (&entry->srcs, i);
+ fprintf (file, "<edge id=\"%d\" source=\"%p\" target=\"%p\"/>\n", edge_id++, sgen_hash_table_key_for_value_pointer (src), obj);
+ }
+ } SGEN_HASH_TABLE_FOREACH_END;
+ fprintf (file, "</edges>\n");
+
+ fprintf (file, "</graph></gexf>\n");
+
+ fclose (file);
+}
+
+static void
+set_dump_prefix (const char *prefix)
+{
+ dump_prefix = strdup (prefix);
}
static int
compare_hash_entries (const HashEntry *e1, const HashEntry *e2)
{
- return e2->finishing_time - e1->finishing_time;
+ /* We can cast to signed int here because finishing_time has only 31 bits. */
+ return (gint32)e2->v.dfs1.finishing_time - (gint32)e1->v.dfs1.finishing_time;
}
DEF_QSORT_INLINE(hash_entries, HashEntry*, compare_hash_entries)
-static unsigned long step_1, step_2, step_3, step_4, step_5, step_6, step_7, step_8;
+static unsigned long step_1, step_2, step_3, step_4, step_5, step_6;
static int fist_pass_links, second_pass_links, sccs_links;
static int max_sccs_links = 0;
static void
reset_data (void)
{
- dyn_array_ptr_set_size (®istered_bridges, 0);
+ dyn_array_ptr_empty (®istered_bridges);
}
static void
{
int i;
int bridge_count;
+ MonoObject *obj;
+ HashEntry *entry;
SGEN_TV_DECLARE (atv);
SGEN_TV_DECLARE (btv);
if (!dyn_array_ptr_size (®istered_bridges))
return;
- /*
- * bridge_processing_in_progress must be set with the world
- * stopped. If not there would be race conditions.
- */
- bridge_processing_in_progress = TRUE;
-
SGEN_TV_GETTIME (btv);
/* first DFS pass */
for (i = 0; i < bridge_count; ++i)
dfs1 (get_hash_entry (dyn_array_ptr_get (®istered_bridges, i), NULL));
+ /* Remove all forwarded objects. */
+ SGEN_HASH_TABLE_FOREACH (&hash_table, obj, entry) {
+ if (entry->v.dfs1.forwarded_to) {
+ g_assert (dyn_array_ptr_size (&entry->srcs) == 0);
+ SGEN_HASH_TABLE_FOREACH_REMOVE (TRUE);
+ continue;
+ }
+ } SGEN_HASH_TABLE_FOREACH_END;
+
SGEN_TV_GETTIME (atv);
step_2 = SGEN_TV_ELAPSED (btv, atv);
-}
-static mono_bool
-is_bridge_object_alive (MonoObject *obj, void *data)
-{
- SgenHashTable *table = data;
- unsigned char *value = sgen_hash_table_lookup (table, obj);
- if (!value)
- return TRUE;
- return *value;
+ if (dump_prefix)
+ dump_graph ();
}
+static int num_registered_bridges, hash_table_size;
+
static void
-processing_finish (int generation)
+processing_build_callback_data (int generation)
{
int i, j;
int num_sccs, num_xrefs;
int max_entries, max_xrefs;
- int hash_table_size, sccs_size;
+ int sccs_size;
MonoObject *obj;
HashEntry *entry;
- int num_registered_bridges;
HashEntry **all_entries;
MonoGCBridgeSCC **api_sccs;
MonoGCBridgeXRef *api_xrefs;
- SgenHashTable alive_hash = SGEN_HASH_TABLE_INIT (INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE, INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE_ENTRY, 1, mono_aligned_addr_hash, NULL);
SGEN_TV_DECLARE (atv);
SGEN_TV_DECLARE (btv);
+ g_assert (bridge_processor->num_sccs == 0 && bridge_processor->num_xrefs == 0);
+ g_assert (!bridge_processor->api_sccs && !bridge_processor->api_xrefs);
+
if (!dyn_array_ptr_size (®istered_bridges))
return;
j = 0;
SGEN_HASH_TABLE_FOREACH (&hash_table, obj, entry) {
- g_assert (entry->finishing_time >= 0);
+ g_assert (entry->v.dfs1.finishing_time > 0);
all_entries [j++] = entry;
fist_pass_links += dyn_array_ptr_size (&entry->srcs);
} SGEN_HASH_TABLE_FOREACH_END;
/* sort array according to decreasing finishing time */
qsort_hash_entries (all_entries, hash_table.num_entries);
+ SGEN_HASH_TABLE_FOREACH (&hash_table, obj, entry) {
+ entry->v.dfs2.scc_index = -1;
+ } SGEN_HASH_TABLE_FOREACH_END;
+
SGEN_TV_GETTIME (btv);
step_3 = SGEN_TV_ELAPSED (atv, btv);
dyn_array_scc_init (&sccs);
for (i = 0; i < hash_table.num_entries; ++i) {
HashEntry *entry = all_entries [i];
- if (entry->scc_index < 0) {
+ if (entry->v.dfs2.scc_index < 0) {
int index = dyn_array_scc_size (&sccs);
current_scc = dyn_array_scc_add (&sccs);
current_scc->index = index;
current_scc->num_bridge_entries = 0;
+#ifdef NEW_XREFS
+ current_scc->flag = FALSE;
+ dyn_array_int_init (¤t_scc->new_xrefs);
+#endif
+#ifdef OLD_XREFS
+ dyn_array_int_init (¤t_scc->old_xrefs);
+#endif
current_scc->api_index = -1;
- dyn_array_int_init (¤t_scc->xrefs);
dfs2 (entry);
+
+#ifdef NEW_XREFS
+ /*
+ * If a node has only one incoming edge, we just copy the source's
+ * xrefs array, effectively removing the source from the graph.
+ * This takes care of long linked lists.
+ */
+ if (!current_scc->num_bridge_entries && dyn_array_int_size (¤t_scc->new_xrefs) == 1) {
+ SCC *src;
+ j = dyn_array_int_get (¤t_scc->new_xrefs, 0);
+ src = dyn_array_scc_get_ptr (&sccs, j);
+ if (src->num_bridge_entries)
+ dyn_array_int_set (¤t_scc->new_xrefs, 0, j);
+ else
+ dyn_array_int_copy (¤t_scc->new_xrefs, &src->new_xrefs);
+ }
+#endif
+ }
+ }
+
+#ifdef NEW_XREFS
+#ifdef TEST_NEW_XREFS
+ for (j = 0; j < dyn_array_scc_size (&sccs); ++j) {
+ SCC *scc = dyn_array_scc_get_ptr (&sccs, j);
+ g_assert (!scc->flag);
+ }
+#endif
+
+ for (i = 0; i < dyn_array_scc_size (&sccs); ++i) {
+ SCC *scc = dyn_array_scc_get_ptr (&sccs, i);
+ g_assert (scc->index == i);
+ if (!scc->num_bridge_entries)
+ continue;
+
+ dyn_array_int_empty (&merge_array);
+ gather_xrefs (scc);
+ reset_flags (scc);
+ dyn_array_int_copy (&scc->new_xrefs, &merge_array);
+ dyn_array_int_ensure_independent (&scc->new_xrefs);
+
+#ifdef TEST_NEW_XREFS
+ for (j = 0; j < dyn_array_scc_size (&sccs); ++j) {
+ SCC *scc = dyn_array_scc_get_ptr (&sccs, j);
+ g_assert (!scc->flag);
}
+#endif
}
+#ifdef TEST_NEW_XREFS
+ for (i = 0; i < dyn_array_scc_size (&sccs); ++i) {
+ SCC *scc = dyn_array_scc_get_ptr (&sccs, i);
+ g_assert (scc->index == i);
+ if (!scc->num_bridge_entries)
+ continue;
+
+ g_assert (dyn_array_int_size (&scc->new_xrefs) == dyn_array_int_size (&scc->old_xrefs));
+ for (j = 0; j < dyn_array_int_size (&scc->new_xrefs); ++j)
+ g_assert (dyn_array_int_contains (&scc->old_xrefs, dyn_array_int_get (&scc->new_xrefs, j)));
+ }
+#endif
+#endif
+
/*
* Compute the weight of each object. The weight of an object is its size plus the size of all
* objects it points do. When the an object is pointed by multiple objects we distribute it's weight
double w;
HashEntryWithAccounting *entry = (HashEntryWithAccounting*)all_entries [i];
- entry->weight += (double)sgen_safe_object_get_size (entry->entry.obj);
+ entry->weight += (double)sgen_safe_object_get_size (sgen_hash_table_key_for_value_pointer (entry));
w = entry->weight / dyn_array_ptr_size (&entry->entry.srcs);
for (j = 0; j < dyn_array_ptr_size (&entry->entry.srcs); ++j) {
HashEntryWithAccounting *other = (HashEntryWithAccounting *)dyn_array_ptr_get (&entry->entry.srcs, j);
for (i = 0; i < hash_table.num_entries; ++i) {
HashEntryWithAccounting *entry = (HashEntryWithAccounting*)all_entries [i];
if (entry->entry.is_bridge) {
- MonoClass *klass = ((MonoVTable*)SGEN_LOAD_VTABLE (entry->entry.obj))->klass;
- mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "OBJECT %s::%s (%p) weight %f", klass->name_space, klass->name, entry->entry.obj, entry->weight);
+ MonoObject *obj = sgen_hash_table_key_for_value_pointer (entry);
+ MonoClass *klass = ((MonoVTable*)SGEN_LOAD_VTABLE (obj))->klass;
+ mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "OBJECT %s::%s (%p) weight %f", klass->name_space, klass->name, obj, entry->weight);
}
}
}
g_assert (scc->index == i);
if (scc->num_bridge_entries)
++num_sccs;
- sccs_links += dyn_array_int_size (&scc->xrefs);
- max_sccs_links = MAX (max_sccs_links, dyn_array_int_size (&scc->xrefs));
+ sccs_links += dyn_array_int_size (&scc->XREFS);
+ max_sccs_links = MAX (max_sccs_links, dyn_array_int_size (&scc->XREFS));
}
api_sccs = sgen_alloc_internal_dynamic (sizeof (MonoGCBridgeSCC*) * num_sccs, INTERNAL_MEM_BRIDGE_DATA, TRUE);
scc->num_bridge_entries = 0;
scc->api_index = j++;
- num_xrefs += dyn_array_int_size (&scc->xrefs);
+ num_xrefs += dyn_array_int_size (&scc->XREFS);
}
SGEN_HASH_TABLE_FOREACH (&hash_table, obj, entry) {
if (entry->is_bridge) {
- SCC *scc = dyn_array_scc_get_ptr (&sccs, entry->scc_index);
- api_sccs [scc->api_index]->objs [scc->num_bridge_entries++] = entry->obj;
+ SCC *scc = dyn_array_scc_get_ptr (&sccs, entry->v.dfs2.scc_index);
+ api_sccs [scc->api_index]->objs [scc->num_bridge_entries++] = sgen_hash_table_key_for_value_pointer (entry);
}
} SGEN_HASH_TABLE_FOREACH_END;
SCC *scc = dyn_array_scc_get_ptr (&sccs, i);
if (!scc->num_bridge_entries)
continue;
- for (k = 0; k < dyn_array_int_size (&scc->xrefs); ++k) {
- SCC *src_scc = dyn_array_scc_get_ptr (&sccs, dyn_array_int_get (&scc->xrefs, k));
+ for (k = 0; k < dyn_array_int_size (&scc->XREFS); ++k) {
+ SCC *src_scc = dyn_array_scc_get_ptr (&sccs, dyn_array_int_get (&scc->XREFS, k));
if (!src_scc->num_bridge_entries)
continue;
api_xrefs [j].src_scc_index = src_scc->api_index;
++j;
if (scc->num_bridge_entries > max_entries)
max_entries = scc->num_bridge_entries;
- if (dyn_array_int_size (&scc->xrefs) > max_xrefs)
- max_xrefs = dyn_array_int_size (&scc->xrefs);
- dyn_array_int_uninit (&scc->xrefs);
+ if (dyn_array_int_size (&scc->XREFS) > max_xrefs)
+ max_xrefs = dyn_array_int_size (&scc->XREFS);
+#ifdef NEW_XREFS
+ dyn_array_int_uninit (&scc->new_xrefs);
+#endif
+#ifdef OLD_XREFS
+ dyn_array_int_uninit (&scc->old_xrefs);
+#endif
}
dyn_array_scc_uninit (&sccs);
free_data ();
/* Empty the registered bridges array */
num_registered_bridges = dyn_array_ptr_size (®istered_bridges);
- dyn_array_ptr_set_size (®istered_bridges, 0);
+ dyn_array_ptr_empty (®istered_bridges);
SGEN_TV_GETTIME (atv);
step_6 = SGEN_TV_ELAPSED (btv, atv);
//g_print ("%d sccs containing bridges - %d max bridge objects - %d max xrefs\n", j, max_entries, max_xrefs);
- /* callback */
-
- bridge_callbacks.cross_references (num_sccs, api_sccs, num_xrefs, api_xrefs);
-
- /* Release for finalization those objects we no longer care. */
- SGEN_TV_GETTIME (btv);
- step_7 = SGEN_TV_ELAPSED (atv, btv);
-
- for (i = 0; i < num_sccs; ++i) {
- unsigned char alive = api_sccs [i]->is_alive ? 1 : 0;
- for (j = 0; j < api_sccs [i]->num_objs; ++j) {
- /* Build hash table for nulling weak links. */
- sgen_hash_table_replace (&alive_hash, api_sccs [i]->objs [j], &alive, NULL);
-
- /* Release for finalization those objects we no longer care. */
- if (!api_sccs [i]->is_alive)
- sgen_mark_bridge_object (api_sccs [i]->objs [j]);
- }
- }
-
- /* Null weak links to dead objects. */
- sgen_null_links_with_predicate (GENERATION_NURSERY, is_bridge_object_alive, &alive_hash);
- if (generation == GENERATION_OLD)
- sgen_null_links_with_predicate (GENERATION_OLD, is_bridge_object_alive, &alive_hash);
+ bridge_processor->num_sccs = num_sccs;
+ bridge_processor->api_sccs = api_sccs;
+ bridge_processor->num_xrefs = num_xrefs;
+ bridge_processor->api_xrefs = api_xrefs;
+}
- sgen_hash_table_clean (&alive_hash);
+static void
+processing_after_callback (int generation)
+{
+ int i, j;
+ int num_sccs = bridge_processor->num_sccs;
+ MonoGCBridgeSCC **api_sccs = bridge_processor->api_sccs;
if (bridge_accounting_enabled) {
for (i = 0; i < num_sccs; ++i) {
}
}
- /* free callback data */
-
- for (i = 0; i < num_sccs; ++i) {
- sgen_free_internal_dynamic (api_sccs [i],
- sizeof (MonoGCBridgeSCC) + sizeof (MonoObject*) * api_sccs [i]->num_objs,
- INTERNAL_MEM_BRIDGE_DATA);
- }
- sgen_free_internal_dynamic (api_sccs, sizeof (MonoGCBridgeSCC*) * num_sccs, INTERNAL_MEM_BRIDGE_DATA);
-
- sgen_free_internal_dynamic (api_xrefs, sizeof (MonoGCBridgeXRef) * num_xrefs, INTERNAL_MEM_BRIDGE_DATA);
-
- SGEN_TV_GETTIME (atv);
- step_8 = SGEN_TV_ELAPSED (btv, atv);
-
- mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_BRIDGE num-objects %d num_hash_entries %d sccs size %d init %.2fms df1 %.2fms sort %.2fms dfs2 %.2fms setup-cb %.2fms free-data %.2fms user-cb %.2fms clenanup %.2fms links %d/%d/%d/%d dfs passes %d/%d",
+ mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_NEW_BRIDGE num-objects %d num_hash_entries %d sccs size %d init %.2fms df1 %.2fms sort %.2fms dfs2 %.2fms setup-cb %.2fms free-data %.2fms links %d/%d/%d/%d dfs passes %d/%d ignored %d",
num_registered_bridges, hash_table_size, dyn_array_scc_size (&sccs),
step_1 / 10000.0f,
step_2 / 10000.0f,
step_4 / 10000.0f,
step_5 / 10000.0f,
step_6 / 10000.0f,
- step_7 / 10000.0f,
- step_8 / 10000.f,
fist_pass_links, second_pass_links, sccs_links, max_sccs_links,
- dfs1_passes, dfs2_passes);
+ dfs1_passes, dfs2_passes, ignored_objects);
step_1 = 0; /* We must cleanup since this value is used as an accumulator. */
fist_pass_links = second_pass_links = sccs_links = max_sccs_links = 0;
- dfs1_passes = dfs2_passes = 0;
-
- bridge_processing_in_progress = FALSE;
+ dfs1_passes = dfs2_passes = ignored_objects = 0;
}
static void
printf ("Bridge hash table entry %p:\n", entry);
printf (" is bridge: %d\n", (int)entry->is_bridge);
- printf (" is visited: %d\n", (int)entry->is_visited);
+ printf (" is visited: %d\n", (int)entry->v.dfs1.is_visited);
}
void
{
collector->reset_data = reset_data;
collector->processing_stw_step = processing_stw_step;
- collector->processing_finish = processing_finish;
+ collector->processing_build_callback_data = processing_build_callback_data;
+ collector->processing_after_callback = processing_after_callback;
collector->class_kind = class_kind;
collector->register_finalized_object = register_finalized_object;
collector->describe_pointer = describe_pointer;
collector->enable_accounting = enable_accounting;
+ collector->set_dump_prefix = set_dump_prefix;
+
+ bridge_processor = collector;
}
#endif