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Diffstat (limited to 'src/liblzma/common/memory_limiter.c')
-rw-r--r-- | src/liblzma/common/memory_limiter.c | 288 |
1 files changed, 0 insertions, 288 deletions
diff --git a/src/liblzma/common/memory_limiter.c b/src/liblzma/common/memory_limiter.c deleted file mode 100644 index a2a0cbdc..00000000 --- a/src/liblzma/common/memory_limiter.c +++ /dev/null @@ -1,288 +0,0 @@ -/////////////////////////////////////////////////////////////////////////////// -// -/// \file memory_limiter.c -/// \brief Limitting memory usage -// -// Copyright (C) 2007 Lasse Collin -// -// This library is free software; you can redistribute it and/or -// modify it under the terms of the GNU Lesser General Public -// License as published by the Free Software Foundation; either -// version 2.1 of the License, or (at your option) any later version. -// -// This library is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -// Lesser General Public License for more details. -// -/////////////////////////////////////////////////////////////////////////////// - -#include "common.h" - - -/// Rounds an unsigned integer upwards to the next multiple. -#define my_ceil(num, multiple) \ - ((num) + (((multiple) - ((num) % (multiple))) % (multiple))) - - -/// Add approximated overhead of malloc() to size and round upwards to the -/// next multiple of 2 * sizeof(size_t). I suppose that most malloc() -/// implementations align small allocations this way, but the overhead -/// varies due to several reasons (free lists, mmap() usage etc.). -/// -/// This doesn't need to be exact at all. It's enough to take into account -/// that there is some overhead. That way our memory usage count won't be -/// horribly wrong if we are used to allocate lots of small memory chunks. -#define malloc_ceil(size) \ - my_ceil((size) + 2 * sizeof(void *), 2 * sizeof(size_t)) - - -typedef struct lzma_memlimit_list_s lzma_memlimit_list; -struct lzma_memlimit_list_s { - lzma_memlimit_list *next; - void *ptr; - size_t size; -}; - - -struct lzma_memlimit_s { - /// List of allocated memory chunks - lzma_memlimit_list *list; - - /// Number of bytes currently allocated; this includes the memory - /// needed for the helper structures. - size_t used; - - /// Memory usage limit - size_t limit; - - /// Maximum amount of memory that have been or would have been needed. - /// That is, this is updated also if memory allocation fails, letting - /// the application check how much memory was tried to be allocated - /// in total. - size_t max; - - /// True if lzma_memlimit_alloc() has returned NULL due to memory - /// usage limit. - bool limit_reached; -}; - - -extern LZMA_API lzma_memlimit * -lzma_memlimit_create(size_t limit) -{ - const size_t base_size = malloc_ceil(sizeof(lzma_memlimit)); - - if (limit < base_size) - return NULL; - - lzma_memlimit *mem = malloc(sizeof(lzma_memlimit)); - - if (mem != NULL) { - mem->list = NULL; - mem->used = base_size; - mem->limit = limit; - mem->max = base_size; - mem->limit_reached = false; - } - - return mem; -} - - -extern LZMA_API void -lzma_memlimit_set(lzma_memlimit *mem, size_t limit) -{ - mem->limit = limit; - return; -} - - -extern LZMA_API size_t -lzma_memlimit_get(const lzma_memlimit *mem) -{ - return mem->limit; -} - - -extern LZMA_API size_t -lzma_memlimit_used(const lzma_memlimit *mem) -{ - return mem->used; -} - - -extern LZMA_API size_t -lzma_memlimit_max(lzma_memlimit *mem, lzma_bool clear) -{ - const size_t ret = mem->max; - - if (clear) - mem->max = mem->used; - - return ret; -} - - -extern LZMA_API lzma_bool -lzma_memlimit_reached(lzma_memlimit *mem, lzma_bool clear) -{ - const bool ret = mem->limit_reached; - - if (clear) - mem->limit_reached = false; - - return ret; -} - - -extern LZMA_API size_t -lzma_memlimit_count(const lzma_memlimit *mem) -{ - // This is slow; we could have a counter in lzma_memlimit - // for fast version. I expect the primary use of this - // function to be limited to easy checking of memory leaks, - // in which this implementation is just fine. - size_t count = 0; - const lzma_memlimit_list *record = mem->list; - - while (record != NULL) { - ++count; - record = record->next; - } - - return count; -} - - -extern LZMA_API void -lzma_memlimit_end(lzma_memlimit *mem, lzma_bool free_allocated) -{ - if (mem == NULL) - return; - - lzma_memlimit_list *record = mem->list; - while (record != NULL) { - if (free_allocated) - free(record->ptr); - - lzma_memlimit_list *tmp = record; - record = record->next; - free(tmp); - } - - free(mem); - - return; -} - - -extern LZMA_API void * -lzma_memlimit_alloc(lzma_memlimit *mem, size_t nmemb, size_t size) -{ - // While liblzma always sets nmemb to one, do this multiplication - // to make these functions usable e.g. with zlib and libbzip2. - // Making sure that this doesn't overflow is up to the application. - size *= nmemb; - - // Some malloc() implementations return NULL on malloc(0). We like - // to get a non-NULL value. - if (size == 0) - size = 1; - - // Calculate how much memory we are going to allocate in reality. - const size_t total_size = malloc_ceil(size) - + malloc_ceil(sizeof(lzma_memlimit_list)); - - // Integer overflow protection for total_size and mem->used. - if (total_size <= size || SIZE_MAX - total_size < mem->used) { - mem->max = SIZE_MAX; - mem->limit_reached = true; - return NULL; - } - - // Update the maximum memory requirement counter if needed. This - // is updated even if memory allocation would fail or limit would - // be reached. - if (mem->used + total_size > mem->max) - mem->max = mem->used + total_size; - - // Check if we would stay in the memory usage limits. We need to - // check also that the current usage is in the limits, because - // the application could have decreased the limit between calls - // to this function. - if (mem->limit < mem->used || mem->limit - mem->used < total_size) { - mem->limit_reached = true; - return NULL; - } - - // Allocate separate memory chunks for lzma_memlimit_list and the - // actual requested memory. Optimizing this to use only one - // allocation is not a good idea, because applications may want to - // detach lzma_extra structures that have been allocated with - // lzma_memlimit_alloc(). - lzma_memlimit_list *record = malloc(sizeof(lzma_memlimit_list)); - void *ptr = malloc(size); - - if (record == NULL || ptr == NULL) { - free(record); - free(ptr); - return NULL; - } - - // Add the new entry to the beginning of the list. This should be - // more efficient when freeing memory, because usually it is - // "last allocated, first freed". - record->next = mem->list; - record->ptr = ptr; - record->size = total_size; - - mem->list = record; - mem->used += total_size; - - return ptr; -} - - -extern LZMA_API void -lzma_memlimit_detach(lzma_memlimit *mem, void *ptr) -{ - if (ptr == NULL || mem->list == NULL) - return; - - lzma_memlimit_list *record = mem->list; - lzma_memlimit_list *prev = NULL; - - while (record->ptr != ptr) { - prev = record; - record = record->next; - if (record == NULL) - return; - } - - if (prev != NULL) - prev->next = record->next; - else - mem->list = record->next; - - assert(mem->used >= record->size); - mem->used -= record->size; - - free(record); - - return; -} - - -extern LZMA_API void -lzma_memlimit_free(lzma_memlimit *mem, void *ptr) -{ - if (ptr == NULL) - return; - - lzma_memlimit_detach(mem, ptr); - - free(ptr); - - return; -} |