1 /* zmalloc - total amount of allocated memory aware version of malloc() 2 * 3 * Copyright (c) 2009-2010, Salvatore Sanfilippo <antirez at gmail dot com> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are met: 8 * 9 * * Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * * Neither the name of Redis nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without 16 * specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <stdio.h> 32 #include <stdlib.h> 33 34 /* This function provide us access to the original libc free(). This is useful 35 * for instance to free results obtained by backtrace_symbols(). We need 36 * to define this function before including zmalloc.h that may shadow the 37 * free implementation if we use jemalloc or another non standard allocator. */ 38 void zlibc_free(void *ptr) { 39 free(ptr); 40 } 41 42 #include <string.h> 43 #include <pthread.h> 44 #include "config.h" 45 #include "zmalloc.h" 46 47 #ifdef HAVE_MALLOC_SIZE 48 #define PREFIX_SIZE (0) 49 #else 50 #if defined(__sun) || defined(__sparc) || defined(__sparc__) 51 #define PREFIX_SIZE (sizeof(long long)) 52 #else 53 #define PREFIX_SIZE (sizeof(size_t)) 54 #endif 55 #endif 56 57 /* Explicitly override malloc/free etc when using tcmalloc. */ 58 #if defined(USE_TCMALLOC) 59 #define malloc(size) tc_malloc(size) 60 #define calloc(count,size) tc_calloc(count,size) 61 #define realloc(ptr,size) tc_realloc(ptr,size) 62 #define free(ptr) tc_free(ptr) 63 #elif defined(USE_JEMALLOC) 64 #define malloc(size) je_malloc(size) 65 #define calloc(count,size) je_calloc(count,size) 66 #define realloc(ptr,size) je_realloc(ptr,size) 67 #define free(ptr) je_free(ptr) 68 #endif 69 70 #ifdef HAVE_ATOMIC 71 #define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n)) 72 #define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n)) 73 #else 74 #define update_zmalloc_stat_add(__n) do { \ 75 pthread_mutex_lock(&used_memory_mutex); \ 76 used_memory += (__n); \ 77 pthread_mutex_unlock(&used_memory_mutex); \ 78 } while(0) 79 80 #define update_zmalloc_stat_sub(__n) do { \ 81 pthread_mutex_lock(&used_memory_mutex); \ 82 used_memory -= (__n); \ 83 pthread_mutex_unlock(&used_memory_mutex); \ 84 } while(0) 85 86 #endif 87 88 #define update_zmalloc_stat_alloc(__n,__size) do { \ 89 size_t _n = (__n); \ 90 if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \ 91 if (zmalloc_thread_safe) { \ 92 update_zmalloc_stat_add(_n); \ 93 } else { \ 94 used_memory += _n; \ 95 } \ 96 } while(0) 97 98 #define update_zmalloc_stat_free(__n) do { \ 99 size_t _n = (__n); \ 100 if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \ 101 if (zmalloc_thread_safe) { \ 102 update_zmalloc_stat_sub(_n); \ 103 } else { \ 104 used_memory -= _n; \ 105 } \ 106 } while(0) 107 108 static size_t used_memory = 0; 109 static int zmalloc_thread_safe = 0; 110 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER; 111 112 static void zmalloc_oom(size_t size) { 113 fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n", 114 size); 115 fflush(stderr); 116 abort(); 117 } 118 119 void *zmalloc(size_t size) { 120 void *ptr = malloc(size+PREFIX_SIZE); 121 122 if (!ptr) zmalloc_oom(size); 123 #ifdef HAVE_MALLOC_SIZE 124 update_zmalloc_stat_alloc(zmalloc_size(ptr),size); 125 return ptr; 126 #else 127 *((size_t*)ptr) = size; 128 update_zmalloc_stat_alloc(size+PREFIX_SIZE,size); 129 return (char*)ptr+PREFIX_SIZE; 130 #endif 131 } 132 133 void *zcalloc(size_t size) { 134 void *ptr = calloc(1, size+PREFIX_SIZE); 135 136 if (!ptr) zmalloc_oom(size); 137 #ifdef HAVE_MALLOC_SIZE 138 update_zmalloc_stat_alloc(zmalloc_size(ptr),size); 139 return ptr; 140 #else 141 *((size_t*)ptr) = size; 142 update_zmalloc_stat_alloc(size+PREFIX_SIZE,size); 143 return (char*)ptr+PREFIX_SIZE; 144 #endif 145 } 146 147 void *zrealloc(void *ptr, size_t size) { 148 #ifndef HAVE_MALLOC_SIZE 149 void *realptr; 150 #endif 151 size_t oldsize; 152 void *newptr; 153 154 if (ptr == NULL) return zmalloc(size); 155 #ifdef HAVE_MALLOC_SIZE 156 oldsize = zmalloc_size(ptr); 157 newptr = realloc(ptr,size); 158 if (!newptr) zmalloc_oom(size); 159 160 update_zmalloc_stat_free(oldsize); 161 update_zmalloc_stat_alloc(zmalloc_size(newptr),size); 162 return newptr; 163 #else 164 realptr = (char*)ptr-PREFIX_SIZE; 165 oldsize = *((size_t*)realptr); 166 newptr = realloc(realptr,size+PREFIX_SIZE); 167 if (!newptr) zmalloc_oom(size); 168 169 *((size_t*)newptr) = size; 170 update_zmalloc_stat_free(oldsize); 171 update_zmalloc_stat_alloc(size,size); 172 return (char*)newptr+PREFIX_SIZE; 173 #endif 174 } 175 176 /* Provide zmalloc_size() for systems where this function is not provided by 177 * malloc itself, given that in that case we store an header with this 178 * information as the first bytes of every allocation. */ 179 #ifndef HAVE_MALLOC_SIZE 180 size_t zmalloc_size(void *ptr) { 181 void *realptr = (char*)ptr-PREFIX_SIZE; 182 size_t size = *((size_t*)realptr); 183 /* Assume at least that all the allocations are padded at sizeof(long) by 184 * the underlying allocator. */ 185 if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1)); 186 return size+PREFIX_SIZE; 187 } 188 #endif 189 190 void zfree(void *ptr) { 191 #ifndef HAVE_MALLOC_SIZE 192 void *realptr; 193 size_t oldsize; 194 #endif 195 196 if (ptr == NULL) return; 197 #ifdef HAVE_MALLOC_SIZE 198 update_zmalloc_stat_free(zmalloc_size(ptr)); 199 free(ptr); 200 #else 201 realptr = (char*)ptr-PREFIX_SIZE; 202 oldsize = *((size_t*)realptr); 203 update_zmalloc_stat_free(oldsize+PREFIX_SIZE); 204 free(realptr); 205 #endif 206 } 207 208 char *zstrdup(const char *s) { 209 size_t l = strlen(s)+1; 210 char *p = zmalloc(l); 211 212 memcpy(p,s,l); 213 return p; 214 } 215 216 size_t zmalloc_used_memory(void) { 217 size_t um; 218 219 if (zmalloc_thread_safe) { 220 #ifdef HAVE_ATOMIC 221 um = __sync_add_and_fetch(&used_memory, 0); 222 #else 223 pthread_mutex_lock(&used_memory_mutex); 224 um = used_memory; 225 pthread_mutex_unlock(&used_memory_mutex); 226 #endif 227 } 228 else { 229 um = used_memory; 230 } 231 232 return um; 233 } 234 235 void zmalloc_enable_thread_safeness(void) { 236 zmalloc_thread_safe = 1; 237 } 238 239 /* Get the RSS information in an OS-specific way. 240 * 241 * WARNING: the function zmalloc_get_rss() is not designed to be fast 242 * and may not be called in the busy loops where Redis tries to release 243 * memory expiring or swapping out objects. 244 * 245 * For this kind of "fast RSS reporting" usages use instead the 246 * function RedisEstimateRSS() that is a much faster (and less precise) 247 * version of the funciton. */ 248 249 #if defined(HAVE_PROCFS) 250 #include <unistd.h> 251 #include <sys/types.h> 252 #include <sys/stat.h> 253 #include <fcntl.h> 254 255 size_t zmalloc_get_rss(void) { 256 int page = sysconf(_SC_PAGESIZE); 257 size_t rss; 258 char buf[4096]; 259 char filename[256]; 260 int fd, count; 261 char *p, *x; 262 263 snprintf(filename,256,"/proc/%d/stat",getpid()); 264 if ((fd = open(filename,O_RDONLY)) == -1) return 0; 265 if (read(fd,buf,4096) <= 0) { 266 close(fd); 267 return 0; 268 } 269 close(fd); 270 271 p = buf; 272 count = 23; /* RSS is the 24th field in /proc/<pid>/stat */ 273 while(p && count--) { 274 p = strchr(p,' '); 275 if (p) p++; 276 } 277 if (!p) return 0; 278 x = strchr(p,' '); 279 if (!x) return 0; 280 *x = '\0'; 281 282 rss = strtoll(p,NULL,10); 283 rss *= page; 284 return rss; 285 } 286 #elif defined(HAVE_TASKINFO) 287 #include <unistd.h> 288 #include <stdio.h> 289 #include <stdlib.h> 290 #include <sys/types.h> 291 #include <sys/sysctl.h> 292 #include <mach/task.h> 293 #include <mach/mach_init.h> 294 295 size_t zmalloc_get_rss(void) { 296 task_t task = MACH_PORT_NULL; 297 struct task_basic_info t_info; 298 mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT; 299 300 if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS) 301 return 0; 302 task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count); 303 304 return t_info.resident_size; 305 } 306 #else 307 size_t zmalloc_get_rss(void) { 308 /* If we can't get the RSS in an OS-specific way for this system just 309 * return the memory usage we estimated in zmalloc().. 310 * 311 * Fragmentation will appear to be always 1 (no fragmentation) 312 * of course... */ 313 return zmalloc_used_memory(); 314 } 315 #endif 316 317 /* Fragmentation = RSS / allocated-bytes */ 318 float zmalloc_get_fragmentation_ratio(void) { 319 return (float)zmalloc_get_rss()/zmalloc_used_memory(); 320 } 321