src/zmalloc.c

   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 #include <string.h>
  34 #include <pthread.h>
  35 #include "config.h"
  36 #include "zmalloc.h"
  37
  38 #ifdef HAVE_MALLOC_SIZE
  39 #define PREFIX_SIZE (0)
  40 #else
  41 #if defined(__sun) || defined(__sparc) || defined(__sparc__)
  42 #define PREFIX_SIZE (sizeof(long long))
  43 #else
  44 #define PREFIX_SIZE (sizeof(size_t))
  45 #endif
  46 #endif
  47
  48 /* Explicitly override malloc/free etc when using tcmalloc. */
  49 #if defined(USE_TCMALLOC)
  50 #define malloc(size) tc_malloc(size)
  51 #define calloc(count,size) tc_calloc(count,size)
  52 #define realloc(ptr,size) tc_realloc(ptr,size)
  53 #define free(ptr) tc_free(ptr)
  54 #elif defined(USE_JEMALLOC)
  55 #define malloc(size) je_malloc(size)
  56 #define calloc(count,size) je_calloc(count,size)
  57 #define realloc(ptr,size) je_realloc(ptr,size)
  58 #define free(ptr) je_free(ptr)
  59 #endif
  60
  61 #ifdef HAVE_ATOMIC
  62 #define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
  63 #define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
  64 #else
  65 #define update_zmalloc_stat_add(__n) do { \
  66     pthread_mutex_lock(&used_memory_mutex); \
  67     used_memory += (__n); \
  68     pthread_mutex_unlock(&used_memory_mutex); \
  69 } while(0)
  70
  71 #define update_zmalloc_stat_sub(__n) do { \
  72     pthread_mutex_lock(&used_memory_mutex); \
  73     used_memory -= (__n); \
  74     pthread_mutex_unlock(&used_memory_mutex); \
  75 } while(0)
  76
  77 #endif
  78
  79 #define update_zmalloc_stat_alloc(__n,__size) do { \
  80     size_t _n = (__n); \
  81     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  82     if (zmalloc_thread_safe) { \
  83         update_zmalloc_stat_add(_n); \
  84     } else { \
  85         used_memory += _n; \
  86     } \
  87 } while(0)
  88
  89 #define update_zmalloc_stat_free(__n) do { \
  90     size_t _n = (__n); \
  91     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  92     if (zmalloc_thread_safe) { \
  93         update_zmalloc_stat_sub(_n); \
  94     } else { \
  95         used_memory -= _n; \
  96     } \
  97 } while(0)
  98
  99 static size_t used_memory = 0;
 100 static int zmalloc_thread_safe = 0;
 101 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
 102
 103 static void zmalloc_oom(size_t size) {
 104     fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
 105         size);
 106     fflush(stderr);
 107     abort();
 108 }
 109
 110 void *zmalloc(size_t size) {
 111     void *ptr = malloc(size+PREFIX_SIZE);
 112
 113     if (!ptr) zmalloc_oom(size);
 114 #ifdef HAVE_MALLOC_SIZE
 115     update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
 116     return ptr;
 117 #else
 118     *((size_t*)ptr) = size;
 119     update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
 120     return (char*)ptr+PREFIX_SIZE;
 121 #endif
 122 }
 123
 124 void *zcalloc(size_t size) {
 125     void *ptr = calloc(1, size+PREFIX_SIZE);
 126
 127     if (!ptr) zmalloc_oom(size);
 128 #ifdef HAVE_MALLOC_SIZE
 129     update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
 130     return ptr;
 131 #else
 132     *((size_t*)ptr) = size;
 133     update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
 134     return (char*)ptr+PREFIX_SIZE;
 135 #endif
 136 }
 137
 138 void *zrealloc(void *ptr, size_t size) {
 139 #ifndef HAVE_MALLOC_SIZE
 140     void *realptr;
 141 #endif
 142     size_t oldsize;
 143     void *newptr;
 144
 145     if (ptr == NULL) return zmalloc(size);
 146 #ifdef HAVE_MALLOC_SIZE
 147     oldsize = zmalloc_size(ptr);
 148     newptr = realloc(ptr,size);
 149     if (!newptr) zmalloc_oom(size);
 150
 151     update_zmalloc_stat_free(oldsize);
 152     update_zmalloc_stat_alloc(zmalloc_size(newptr),size);
 153     return newptr;
 154 #else
 155     realptr = (char*)ptr-PREFIX_SIZE;
 156     oldsize = *((size_t*)realptr);
 157     newptr = realloc(realptr,size+PREFIX_SIZE);
 158     if (!newptr) zmalloc_oom(size);
 159
 160     *((size_t*)newptr) = size;
 161     update_zmalloc_stat_free(oldsize);
 162     update_zmalloc_stat_alloc(size,size);
 163     return (char*)newptr+PREFIX_SIZE;
 164 #endif
 165 }
 166
 167 /* Provide zmalloc_size() for systems where this function is not provided by
 168  * malloc itself, given that in that case we store an header with this
 169  * information as the first bytes of every allocation. */
 170 #ifndef HAVE_MALLOC_SIZE
 171 size_t zmalloc_size(void *ptr) {
 172     void *realptr = (char*)ptr-PREFIX_SIZE;
 173     size_t size = *((size_t*)realptr);
 174     /* Assume at least that all the allocations are padded at sizeof(long) by
 175      * the underlying allocator. */
 176     if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1));
 177     return size+PREFIX_SIZE;
 178 }
 179 #endif
 180
 181 void zfree(void *ptr) {
 182 #ifndef HAVE_MALLOC_SIZE
 183     void *realptr;
 184     size_t oldsize;
 185 #endif
 186
 187     if (ptr == NULL) return;
 188 #ifdef HAVE_MALLOC_SIZE
 189     update_zmalloc_stat_free(zmalloc_size(ptr));
 190     free(ptr);
 191 #else
 192     realptr = (char*)ptr-PREFIX_SIZE;
 193     oldsize = *((size_t*)realptr);
 194     update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
 195     free(realptr);
 196 #endif
 197 }
 198
 199 char *zstrdup(const char *s) {
 200     size_t l = strlen(s)+1;
 201     char *p = zmalloc(l);
 202
 203     memcpy(p,s,l);
 204     return p;
 205 }
 206
 207 size_t zmalloc_used_memory(void) {
 208     size_t um;
 209
 210     if (zmalloc_thread_safe) {
 211 #ifdef HAVE_ATOMIC
 212         um = __sync_add_and_fetch(&used_memory, 0);
 213 #else
 214         pthread_mutex_lock(&used_memory_mutex);
 215         um = used_memory;
 216         pthread_mutex_unlock(&used_memory_mutex);
 217 #endif
 218     }
 219     else {
 220         um = used_memory;
 221     }
 222
 223     return um;
 224 }
 225
 226 void zmalloc_enable_thread_safeness(void) {
 227     zmalloc_thread_safe = 1;
 228 }
 229
 230 /* Get the RSS information in an OS-specific way.
 231  *
 232  * WARNING: the function zmalloc_get_rss() is not designed to be fast
 233  * and may not be called in the busy loops where Redis tries to release
 234  * memory expiring or swapping out objects.
 235  *
 236  * For this kind of "fast RSS reporting" usages use instead the
 237  * function RedisEstimateRSS() that is a much faster (and less precise)
 238  * version of the funciton. */
 239
 240 #if defined(HAVE_PROCFS)
 241 #include <unistd.h>
 242 #include <sys/types.h>
 243 #include <sys/stat.h>
 244 #include <fcntl.h>
 245
 246 size_t zmalloc_get_rss(void) {
 247     int page = sysconf(_SC_PAGESIZE);
 248     size_t rss;
 249     char buf[4096];
 250     char filename[256];
 251     int fd, count;
 252     char *p, *x;
 253
 254     snprintf(filename,256,"/proc/%d/stat",getpid());
 255     if ((fd = open(filename,O_RDONLY)) == -1) return 0;
 256     if (read(fd,buf,4096) <= 0) {
 257         close(fd);
 258         return 0;
 259     }
 260     close(fd);
 261
 262     p = buf;
 263     count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
 264     while(p && count--) {
 265         p = strchr(p,' ');
 266         if (p) p++;
 267     }
 268     if (!p) return 0;
 269     x = strchr(p,' ');
 270     if (!x) return 0;
 271     *x = '\0';
 272
 273     rss = strtoll(p,NULL,10);
 274     rss *= page;
 275     return rss;
 276 }
 277 #elif defined(HAVE_TASKINFO)
 278 #include <unistd.h>
 279 #include <stdio.h>
 280 #include <stdlib.h>
 281 #include <sys/types.h>
 282 #include <sys/sysctl.h>
 283 #include <mach/task.h>
 284 #include <mach/mach_init.h>
 285
 286 size_t zmalloc_get_rss(void) {
 287     task_t task = MACH_PORT_NULL;
 288     struct task_basic_info t_info;
 289     mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
 290
 291     if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
 292         return 0;
 293     task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
 294
 295     return t_info.resident_size;
 296 }
 297 #else
 298 size_t zmalloc_get_rss(void) {
 299     /* If we can't get the RSS in an OS-specific way for this system just
 300      * return the memory usage we estimated in zmalloc()..
 301      *
 302      * Fragmentation will appear to be always 1 (no fragmentation)
 303      * of course... */
 304     return zmalloc_used_memory();
 305 }
 306 #endif
 307
 308 /* Fragmentation = RSS / allocated-bytes */
 309 float zmalloc_get_fragmentation_ratio(void) {
 310     return (float)zmalloc_get_rss()/zmalloc_used_memory();
 311 }