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| 1 // Copyright 2012 Google Inc. All Rights Reserved. |
| 2 // |
| 3 // Use of this source code is governed by a BSD-style license |
| 4 // that can be found in the COPYING file in the root of the source |
| 5 // tree. An additional intellectual property rights grant can be found |
| 6 // in the file PATENTS. All contributing project authors may |
| 7 // be found in the AUTHORS file in the root of the source tree. |
| 8 // ----------------------------------------------------------------------------- |
| 9 // |
| 10 // Misc. common utility functions |
| 11 // |
| 12 // Author: Skal (pascal.massimino@gmail.com) |
| 13 |
| 14 #include <stdlib.h> |
| 15 #include "./utils.h" |
| 16 |
| 17 // If PRINT_MEM_INFO is defined, extra info (like total memory used, number of |
| 18 // alloc/free etc) is printed. For debugging/tuning purpose only (it's slow, |
| 19 // and not multi-thread safe!). |
| 20 // An interesting alternative is valgrind's 'massif' tool: |
| 21 // http://valgrind.org/docs/manual/ms-manual.html |
| 22 // Here is an example command line: |
| 23 /* valgrind --tool=massif --massif-out-file=massif.out \ |
| 24 --stacks=yes --alloc-fn=WebPSafeAlloc --alloc-fn=WebPSafeCalloc |
| 25 ms_print massif.out |
| 26 */ |
| 27 // In addition: |
| 28 // * if PRINT_MEM_TRAFFIC is defined, all the details of the malloc/free cycles |
| 29 // are printed. |
| 30 // * if MALLOC_FAIL_AT is defined, the global environment variable |
| 31 // $MALLOC_FAIL_AT is used to simulate a memory error when calloc or malloc |
| 32 // is called for the nth time. Example usage: |
| 33 // export MALLOC_FAIL_AT=50 && ./examples/cwebp input.png |
| 34 // * if MALLOC_LIMIT is defined, the global environment variable $MALLOC_LIMIT |
| 35 // sets the maximum amount of memory (in bytes) made available to libwebp. |
| 36 // This can be used to emulate environment with very limited memory. |
| 37 // Example: export MALLOC_LIMIT=64000000 && ./examples/dwebp picture.webp |
| 38 |
| 39 // #define PRINT_MEM_INFO |
| 40 // #define PRINT_MEM_TRAFFIC |
| 41 // #define MALLOC_FAIL_AT |
| 42 // #define MALLOC_LIMIT |
| 43 |
| 44 //------------------------------------------------------------------------------ |
| 45 // Checked memory allocation |
| 46 |
| 47 #if defined(PRINT_MEM_INFO) |
| 48 |
| 49 #include <stdio.h> |
| 50 #include <stdlib.h> // for abort() |
| 51 |
| 52 static int num_malloc_calls = 0; |
| 53 static int num_calloc_calls = 0; |
| 54 static int num_free_calls = 0; |
| 55 static int countdown_to_fail = 0; // 0 = off |
| 56 |
| 57 typedef struct MemBlock MemBlock; |
| 58 struct MemBlock { |
| 59 void* ptr_; |
| 60 size_t size_; |
| 61 MemBlock* next_; |
| 62 }; |
| 63 |
| 64 static MemBlock* all_blocks = NULL; |
| 65 static size_t total_mem = 0; |
| 66 static size_t total_mem_allocated = 0; |
| 67 static size_t high_water_mark = 0; |
| 68 static size_t mem_limit = 0; |
| 69 |
| 70 static int exit_registered = 0; |
| 71 |
| 72 static void PrintMemInfo(void) { |
| 73 fprintf(stderr, "\nMEMORY INFO:\n"); |
| 74 fprintf(stderr, "num calls to: malloc = %4d\n", num_malloc_calls); |
| 75 fprintf(stderr, " calloc = %4d\n", num_calloc_calls); |
| 76 fprintf(stderr, " free = %4d\n", num_free_calls); |
| 77 fprintf(stderr, "total_mem: %u\n", (uint32_t)total_mem); |
| 78 fprintf(stderr, "total_mem allocated: %u\n", (uint32_t)total_mem_allocated); |
| 79 fprintf(stderr, "high-water mark: %u\n", (uint32_t)high_water_mark); |
| 80 while (all_blocks != NULL) { |
| 81 MemBlock* b = all_blocks; |
| 82 all_blocks = b->next_; |
| 83 free(b); |
| 84 } |
| 85 } |
| 86 |
| 87 static void Increment(int* const v) { |
| 88 if (!exit_registered) { |
| 89 #if defined(MALLOC_FAIL_AT) |
| 90 { |
| 91 const char* const malloc_fail_at_str = getenv("MALLOC_FAIL_AT"); |
| 92 if (malloc_fail_at_str != NULL) { |
| 93 countdown_to_fail = atoi(malloc_fail_at_str); |
| 94 } |
| 95 } |
| 96 #endif |
| 97 #if defined(MALLOC_LIMIT) |
| 98 { |
| 99 const char* const malloc_limit_str = getenv("MALLOC_LIMIT"); |
| 100 if (malloc_limit_str != NULL) { |
| 101 mem_limit = atoi(malloc_limit_str); |
| 102 } |
| 103 } |
| 104 #endif |
| 105 (void)countdown_to_fail; |
| 106 (void)mem_limit; |
| 107 atexit(PrintMemInfo); |
| 108 exit_registered = 1; |
| 109 } |
| 110 ++*v; |
| 111 } |
| 112 |
| 113 static void AddMem(void* ptr, size_t size) { |
| 114 if (ptr != NULL) { |
| 115 MemBlock* const b = (MemBlock*)malloc(sizeof(*b)); |
| 116 if (b == NULL) abort(); |
| 117 b->next_ = all_blocks; |
| 118 all_blocks = b; |
| 119 b->ptr_ = ptr; |
| 120 b->size_ = size; |
| 121 total_mem += size; |
| 122 total_mem_allocated += size; |
| 123 #if defined(PRINT_MEM_TRAFFIC) |
| 124 #if defined(MALLOC_FAIL_AT) |
| 125 fprintf(stderr, "fail-count: %5d [mem=%u]\n", |
| 126 num_malloc_calls + num_calloc_calls, (uint32_t)total_mem); |
| 127 #else |
| 128 fprintf(stderr, "Mem: %u (+%u)\n", (uint32_t)total_mem, (uint32_t)size); |
| 129 #endif |
| 130 #endif |
| 131 if (total_mem > high_water_mark) high_water_mark = total_mem; |
| 132 } |
| 133 } |
| 134 |
| 135 static void SubMem(void* ptr) { |
| 136 if (ptr != NULL) { |
| 137 MemBlock** b = &all_blocks; |
| 138 // Inefficient search, but that's just for debugging. |
| 139 while (*b != NULL && (*b)->ptr_ != ptr) b = &(*b)->next_; |
| 140 if (*b == NULL) { |
| 141 fprintf(stderr, "Invalid pointer free! (%p)\n", ptr); |
| 142 abort(); |
| 143 } |
| 144 { |
| 145 MemBlock* const block = *b; |
| 146 *b = block->next_; |
| 147 total_mem -= block->size_; |
| 148 #if defined(PRINT_MEM_TRAFFIC) |
| 149 fprintf(stderr, "Mem: %u (-%u)\n", |
| 150 (uint32_t)total_mem, (uint32_t)block->size_); |
| 151 #endif |
| 152 free(block); |
| 153 } |
| 154 } |
| 155 } |
| 156 |
| 157 #else |
| 158 #define Increment(v) do {} while (0) |
| 159 #define AddMem(p, s) do {} while (0) |
| 160 #define SubMem(p) do {} while (0) |
| 161 #endif |
| 162 |
| 163 // Returns 0 in case of overflow of nmemb * size. |
| 164 static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) { |
| 165 const uint64_t total_size = nmemb * size; |
| 166 if (nmemb == 0) return 1; |
| 167 if ((uint64_t)size > WEBP_MAX_ALLOCABLE_MEMORY / nmemb) return 0; |
| 168 if (total_size != (size_t)total_size) return 0; |
| 169 #if defined(PRINT_MEM_INFO) && defined(MALLOC_FAIL_AT) |
| 170 if (countdown_to_fail > 0 && --countdown_to_fail == 0) { |
| 171 return 0; // fake fail! |
| 172 } |
| 173 #endif |
| 174 #if defined(MALLOC_LIMIT) |
| 175 if (mem_limit > 0 && total_mem + total_size >= mem_limit) { |
| 176 return 0; // fake fail! |
| 177 } |
| 178 #endif |
| 179 |
| 180 return 1; |
| 181 } |
| 182 |
| 183 void* WebPSafeMalloc(uint64_t nmemb, size_t size) { |
| 184 void* ptr; |
| 185 Increment(&num_malloc_calls); |
| 186 if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL; |
| 187 assert(nmemb * size > 0); |
| 188 ptr = malloc((size_t)(nmemb * size)); |
| 189 AddMem(ptr, (size_t)(nmemb * size)); |
| 190 return ptr; |
| 191 } |
| 192 |
| 193 void* WebPSafeCalloc(uint64_t nmemb, size_t size) { |
| 194 void* ptr; |
| 195 Increment(&num_calloc_calls); |
| 196 if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL; |
| 197 assert(nmemb * size > 0); |
| 198 ptr = calloc((size_t)nmemb, size); |
| 199 AddMem(ptr, (size_t)(nmemb * size)); |
| 200 return ptr; |
| 201 } |
| 202 |
| 203 void WebPSafeFree(void* const ptr) { |
| 204 if (ptr != NULL) { |
| 205 Increment(&num_free_calls); |
| 206 SubMem(ptr); |
| 207 } |
| 208 free(ptr); |
| 209 } |
| 210 |
| 211 //------------------------------------------------------------------------------ |
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