diff options
Diffstat (limited to 'dbus/dbus-mempool.c')
-rw-r--r-- | dbus/dbus-mempool.c | 197 |
1 files changed, 142 insertions, 55 deletions
diff --git a/dbus/dbus-mempool.c b/dbus/dbus-mempool.c index 9a0f6188..437dbfdc 100644 --- a/dbus/dbus-mempool.c +++ b/dbus/dbus-mempool.c @@ -22,6 +22,7 @@ */ #include "dbus-mempool.h" +#include "dbus-internals.h" /** * @defgroup DBusMemPool memory pools @@ -99,6 +100,7 @@ struct DBusMemPool DBusFreedElement *free_elements; /**< a free list of elements to recycle */ DBusMemBlock *blocks; /**< blocks of memory from malloc() */ + int allocated_elements; /* Count of outstanding allocated elements */ }; /** @} */ @@ -156,6 +158,8 @@ _dbus_mem_pool_new (int element_size, pool->zero_elements = zero_elements != FALSE; + pool->allocated_elements = 0; + /* pick a size for the first block; it increases * for each block we need to allocate. This is * actually half the initial block size @@ -202,80 +206,118 @@ _dbus_mem_pool_free (DBusMemPool *pool) void* _dbus_mem_pool_alloc (DBusMemPool *pool) { - if (_dbus_decrement_fail_alloc_counter ()) - { - _dbus_verbose (" FAILING mempool alloc\n"); - return NULL; - } - - if (pool->free_elements) + if (_dbus_disable_mem_pools ()) { - DBusFreedElement *element = pool->free_elements; + DBusMemBlock *block; + int alloc_size; + + /* This is obviously really silly, but it's + * debug-mode-only code that is compiled out + * when tests are disabled (_dbus_disable_mem_pools() + * is a constant expression FALSE so this block + * should vanish) + */ + + alloc_size = sizeof (DBusMemBlock) - ELEMENT_PADDING + + pool->element_size; + + if (pool->zero_elements) + block = dbus_malloc0 (alloc_size); + else + block = dbus_malloc (alloc_size); - pool->free_elements = pool->free_elements->next; + if (block != NULL) + { + block->next = pool->blocks; + pool->blocks = block; + pool->allocated_elements += 1; - if (pool->zero_elements) - memset (element, '\0', pool->element_size); - - return element; + return (void*) &block->elements[0]; + } + else + return NULL; } else { - void *element; + if (_dbus_decrement_fail_alloc_counter ()) + { + _dbus_verbose (" FAILING mempool alloc\n"); + return NULL; + } + else if (pool->free_elements) + { + DBusFreedElement *element = pool->free_elements; + + pool->free_elements = pool->free_elements->next; + + if (pool->zero_elements) + memset (element, '\0', pool->element_size); + + pool->allocated_elements += 1; - if (pool->blocks == NULL || - pool->blocks->used_so_far == pool->block_size) + return element; + } + else { - /* Need a new block */ - DBusMemBlock *block; - int alloc_size; + void *element; + + if (pool->blocks == NULL || + pool->blocks->used_so_far == pool->block_size) + { + /* Need a new block */ + DBusMemBlock *block; + int alloc_size; #ifdef DBUS_BUILD_TESTS - int saved_counter; + int saved_counter; #endif - if (pool->block_size <= _DBUS_INT_MAX / 4) /* avoid overflow */ - { - /* use a larger block size for our next block */ - pool->block_size *= 2; - _dbus_assert ((pool->block_size % - pool->element_size) == 0); - } + if (pool->block_size <= _DBUS_INT_MAX / 4) /* avoid overflow */ + { + /* use a larger block size for our next block */ + pool->block_size *= 2; + _dbus_assert ((pool->block_size % + pool->element_size) == 0); + } - alloc_size = sizeof (DBusMemBlock) - ELEMENT_PADDING + pool->block_size; + alloc_size = sizeof (DBusMemBlock) - ELEMENT_PADDING + pool->block_size; #ifdef DBUS_BUILD_TESTS - /* We save/restore the counter, so that memory pools won't - * cause a given function to have different number of - * allocations on different invocations. i.e. when testing - * we want consistent alloc patterns. So we skip our - * malloc here for purposes of failed alloc simulation. - */ - saved_counter = _dbus_get_fail_alloc_counter (); - _dbus_set_fail_alloc_counter (_DBUS_INT_MAX); + /* We save/restore the counter, so that memory pools won't + * cause a given function to have different number of + * allocations on different invocations. i.e. when testing + * we want consistent alloc patterns. So we skip our + * malloc here for purposes of failed alloc simulation. + */ + saved_counter = _dbus_get_fail_alloc_counter (); + _dbus_set_fail_alloc_counter (_DBUS_INT_MAX); #endif - if (pool->zero_elements) - block = dbus_malloc0 (alloc_size); - else - block = dbus_malloc (alloc_size); + if (pool->zero_elements) + block = dbus_malloc0 (alloc_size); + else + block = dbus_malloc (alloc_size); #ifdef DBUS_BUILD_TESTS - _dbus_set_fail_alloc_counter (saved_counter); + _dbus_set_fail_alloc_counter (saved_counter); + _dbus_assert (saved_counter == _dbus_get_fail_alloc_counter ()); #endif - if (block == NULL) - return NULL; + if (block == NULL) + return NULL; - block->used_so_far = 0; - block->next = pool->blocks; - pool->blocks = block; - } + block->used_so_far = 0; + block->next = pool->blocks; + pool->blocks = block; + } - element = &pool->blocks->elements[pool->blocks->used_so_far]; + element = &pool->blocks->elements[pool->blocks->used_so_far]; - pool->blocks->used_so_far += pool->element_size; + pool->blocks->used_so_far += pool->element_size; - return element; + pool->allocated_elements += 1; + + return element; + } } } @@ -285,16 +327,61 @@ _dbus_mem_pool_alloc (DBusMemPool *pool) * must have come from this same pool. * @param pool the memory pool * @param element the element earlier allocated. + * @returns #TRUE if there are no remaining allocated elements */ -void +dbus_bool_t _dbus_mem_pool_dealloc (DBusMemPool *pool, void *element) { - DBusFreedElement *freed; + if (_dbus_disable_mem_pools ()) + { + DBusMemBlock *block; + DBusMemBlock *prev; + + /* mmm, fast. ;-) debug-only code, so doesn't matter. */ + + prev = NULL; + block = pool->blocks; - freed = element; - freed->next = pool->free_elements; - pool->free_elements = freed; + while (block != NULL) + { + if (block->elements == (unsigned char*) element) + { + if (prev) + prev->next = block->next; + else + pool->blocks = block->next; + + dbus_free (block); + + _dbus_assert (pool->allocated_elements > 0); + pool->allocated_elements -= 1; + + if (pool->allocated_elements == 0) + _dbus_assert (pool->blocks == NULL); + + return pool->blocks == NULL; + } + prev = block; + block = block->next; + } + + _dbus_assert_not_reached ("freed nonexistent block"); + return FALSE; + } + else + { + DBusFreedElement *freed; + + freed = element; + freed->next = pool->free_elements; + pool->free_elements = freed; + + _dbus_assert (pool->allocated_elements > 0); + pool->allocated_elements -= 1; + + return pool->allocated_elements == 0; + } } /** @} */ |