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-rw-r--r--malloc/arena.c203
1 files changed, 187 insertions, 16 deletions
diff --git a/malloc/arena.c b/malloc/arena.c
index cc03dc4..f280d38 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -1,5 +1,5 @@
/* Malloc implementation for multiple threads without lock contention.
- Copyright (C) 2001,2002,2003,2004,2005,2006,2007
+ Copyright (C) 2001,2002,2003,2004,2005,2006,2007,2009
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
@@ -78,6 +78,10 @@ extern int sanity_check_heap_info_alignment[(sizeof (heap_info)
static tsd_key_t arena_key;
static mutex_t list_lock;
+#ifdef PER_THREAD
+static size_t narenas;
+static mstate free_list;
+#endif
#if THREAD_STATS
static int stat_n_heaps;
@@ -105,13 +109,30 @@ int __malloc_initialized = -1;
in the new arena. */
#define arena_get(ptr, size) do { \
+ arena_lookup(ptr); \
+ arena_lock(ptr, size); \
+} while(0)
+
+#define arena_lookup(ptr) do { \
Void_t *vptr = NULL; \
ptr = (mstate)tsd_getspecific(arena_key, vptr); \
+} while(0)
+
+#ifdef PER_THREAD
+#define arena_lock(ptr, size) do { \
+ if(ptr) \
+ (void)mutex_lock(&ptr->mutex); \
+ else \
+ ptr = arena_get2(ptr, (size)); \
+} while(0)
+#else
+#define arena_lock(ptr, size) do { \
if(ptr && !mutex_trylock(&ptr->mutex)) { \
THREAD_STAT(++(ptr->stat_lock_direct)); \
} else \
ptr = arena_get2(ptr, (size)); \
} while(0)
+#endif
/* find the heap and corresponding arena for a given ptr */
@@ -219,6 +240,11 @@ free_atfork(Void_t* mem, const Void_t *caller)
}
#endif
+#ifdef ATOMIC_FASTBINS
+ ar_ptr = arena_for_chunk(p);
+ tsd_getspecific(arena_key, vptr);
+ _int_free(ar_ptr, p, vptr == ATFORK_ARENA_PTR);
+#else
ar_ptr = arena_for_chunk(p);
tsd_getspecific(arena_key, vptr);
if(vptr != ATFORK_ARENA_PTR)
@@ -226,6 +252,7 @@ free_atfork(Void_t* mem, const Void_t *caller)
_int_free(ar_ptr, p);
if(vptr != ATFORK_ARENA_PTR)
(void)mutex_unlock(&ar_ptr->mutex);
+#endif
}
@@ -312,8 +339,17 @@ ptmalloc_unlock_all2 (void)
__malloc_hook = save_malloc_hook;
__free_hook = save_free_hook;
#endif
+#ifdef PER_THREAD
+ free_list = NULL;
+#endif
for(ar_ptr = &main_arena;;) {
mutex_init(&ar_ptr->mutex);
+#ifdef PER_THREAD
+ if (ar_ptr != save_arena) {
+ ar_ptr->next_free = free_list;
+ free_list = ar_ptr;
+ }
+#endif
ar_ptr = ar_ptr->next;
if(ar_ptr == &main_arena) break;
}
@@ -377,6 +413,11 @@ ptmalloc_init_minimal (void)
mp_.mmap_threshold = DEFAULT_MMAP_THRESHOLD;
mp_.trim_threshold = DEFAULT_TRIM_THRESHOLD;
mp_.pagesize = malloc_getpagesize;
+#ifdef PER_THREAD
+# define NARENAS_FROM_NCORES(n) ((n) * (sizeof(long) == 4 ? 2 : 8))
+ mp_.arena_test = NARENAS_FROM_NCORES (1);
+ narenas = 1;
+#endif
}
@@ -529,9 +570,25 @@ ptmalloc_init (void)
}
break;
case 9:
- if (! secure && memcmp (envline, "MMAP_MAX_", 9) == 0)
- mALLOPt(M_MMAP_MAX, atoi(&envline[10]));
+ if (! secure)
+ {
+ if (memcmp (envline, "MMAP_MAX_", 9) == 0)
+ mALLOPt(M_MMAP_MAX, atoi(&envline[10]));
+#ifdef PER_THREAD
+ else if (memcmp (envline, "ARENA_MAX", 9) == 0)
+ mALLOPt(M_ARENA_MAX, atoi(&envline[10]));
+#endif
+ }
break;
+#ifdef PER_THREAD
+ case 10:
+ if (! secure)
+ {
+ if (memcmp (envline, "ARENA_TEST", 10) == 0)
+ mALLOPt(M_ARENA_TEST, atoi(&envline[11]));
+ }
+ break;
+#endif
case 15:
if (! secure)
{
@@ -875,9 +932,110 @@ _int_new_arena(size_t size)
top(a) = (mchunkptr)ptr;
set_head(top(a), (((char*)h + h->size) - ptr) | PREV_INUSE);
+ tsd_setspecific(arena_key, (Void_t *)a);
+ mutex_init(&a->mutex);
+ (void)mutex_lock(&a->mutex);
+
+#ifdef PER_THREAD
+ (void)mutex_lock(&list_lock);
+#endif
+
+ /* Add the new arena to the global list. */
+ a->next = main_arena.next;
+ atomic_write_barrier ();
+ main_arena.next = a;
+
+#ifdef PER_THREAD
+ ++narenas;
+
+ (void)mutex_unlock(&list_lock);
+#endif
+
+ THREAD_STAT(++(a->stat_lock_loop));
+
return a;
}
+
+#ifdef PER_THREAD
+static mstate
+get_free_list (void)
+{
+ mstate result = free_list;
+ if (result != NULL)
+ {
+ (void)mutex_lock(&list_lock);
+ result = free_list;
+ if (result != NULL)
+ free_list = result->next_free;
+ (void)mutex_unlock(&list_lock);
+
+ if (result != NULL)
+ {
+ (void)mutex_lock(&result->mutex);
+ tsd_setspecific(arena_key, (Void_t *)result);
+ THREAD_STAT(++(result->stat_lock_loop));
+ }
+ }
+
+ return result;
+}
+
+
+static mstate
+reused_arena (void)
+{
+ if (narenas <= mp_.arena_test)
+ return NULL;
+
+ static int narenas_limit;
+ if (narenas_limit == 0)
+ {
+ if (mp_.arena_max != 0)
+ narenas_limit = mp_.arena_max;
+ else
+ {
+ int n = __get_nprocs ();
+
+ if (n >= 1)
+ narenas_limit = NARENAS_FROM_NCORES (n);
+ else
+ /* We have no information about the system. Assume two
+ cores. */
+ narenas_limit = NARENAS_FROM_NCORES (2);
+ }
+ }
+
+ if (narenas < narenas_limit)
+ return NULL;
+
+ mstate result;
+ static mstate next_to_use;
+ if (next_to_use == NULL)
+ next_to_use = &main_arena;
+
+ result = next_to_use;
+ do
+ {
+ if (!mutex_trylock(&result->mutex))
+ goto out;
+
+ result = result->next;
+ }
+ while (result != next_to_use);
+
+ /* No arena available. Wait for the next in line. */
+ (void)mutex_lock(&result->mutex);
+
+ out:
+ tsd_setspecific(arena_key, (Void_t *)result);
+ THREAD_STAT(++(result->stat_lock_loop));
+ next_to_use = result->next;
+
+ return result;
+}
+#endif
+
static mstate
internal_function
#if __STD_C
@@ -888,6 +1046,12 @@ arena_get2(a_tsd, size) mstate a_tsd; size_t size;
{
mstate a;
+#ifdef PER_THREAD
+ if ((a = get_free_list ()) == NULL
+ && (a = reused_arena ()) == NULL)
+ /* Nothing immediately available, so generate a new arena. */
+ a = _int_new_arena(size);
+#else
if(!a_tsd)
a = a_tsd = &main_arena;
else {
@@ -930,24 +1094,31 @@ arena_get2(a_tsd, size) mstate a_tsd; size_t size;
/* Nothing immediately available, so generate a new arena. */
a = _int_new_arena(size);
- if(a)
- {
- tsd_setspecific(arena_key, (Void_t *)a);
- mutex_init(&a->mutex);
- mutex_lock(&a->mutex); /* remember result */
-
- /* Add the new arena to the global list. */
- a->next = main_arena.next;
- atomic_write_barrier ();
- main_arena.next = a;
-
- THREAD_STAT(++(a->stat_lock_loop));
- }
(void)mutex_unlock(&list_lock);
+#endif
return a;
}
+#ifdef PER_THREAD
+static void __attribute__ ((section ("__libc_thread_freeres_fn")))
+arena_thread_freeres (void)
+{
+ Void_t *vptr = NULL;
+ mstate a = tsd_getspecific(arena_key, vptr);
+ tsd_setspecific(arena_key, NULL);
+
+ if (a != NULL)
+ {
+ (void)mutex_lock(&list_lock);
+ a->next_free = free_list;
+ free_list = a;
+ (void)mutex_unlock(&list_lock);
+ }
+}
+text_set_element (__libc_thread_subfreeres, arena_thread_freeres);
+#endif
+
#endif /* USE_ARENAS */
/*
generated by cgit v1.1 at 2024-11-22 15:51:00 +0000