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)
  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 #define update_zmalloc_stat_alloc(__n,__size) do { \
  62     size_t _n = (__n); \
  63     size_t _stat_slot = (__size < ZMALLOC_MAX_ALLOC_STAT) ? __size : ZMALLOC_MAX_ALLOC_STAT; \
  64     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  65     if (zmalloc_thread_safe) { \
  66         pthread_mutex_lock(&used_memory_mutex);  \
  67         used_memory += _n; \
  68         zmalloc_allocations[_stat_slot]++; \
  69         pthread_mutex_unlock(&used_memory_mutex); \
  70     } else { \
  71         used_memory += _n; \
  72         zmalloc_allocations[_stat_slot]++; \
  73     } \
  74 } while(0)
  75
  76 #define update_zmalloc_stat_free(__n) do { \
  77     size_t _n = (__n); \
  78     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  79     if (zmalloc_thread_safe) { \
  80         pthread_mutex_lock(&used_memory_mutex);  \
  81         used_memory -= _n; \
  82         pthread_mutex_unlock(&used_memory_mutex); \
  83     } else { \
  84         used_memory -= _n; \
  85     } \
  86 } while(0)
  87
  88 static size_t used_memory = 0;
  89 static int zmalloc_thread_safe = 0;
  90 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
  91 /* Note that malloc_allocations elements are initialized to zero by C */
  92 size_t zmalloc_allocations[ZMALLOC_MAX_ALLOC_STAT+1];
  93
  94 static void zmalloc_oom(size_t size) {
  95     fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
  96         size);
  97     fflush(stderr);
  98     abort();
  99 }
 100
 101 void *zmalloc(size_t size) {
 102     void *ptr = malloc(size+PREFIX_SIZE);
 103
 104     if (!ptr) zmalloc_oom(size);
 105 #ifdef HAVE_MALLOC_SIZE
 106     update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
 107     return ptr;
 108 #else
 109     *((size_t*)ptr) = size;
 110     update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
 111     return (char*)ptr+PREFIX_SIZE;
 112 #endif
 113 }
 114
 115 void *zcalloc(size_t size) {
 116     void *ptr = calloc(1, size+PREFIX_SIZE);
 117
 118     if (!ptr) zmalloc_oom(size);
 119 #ifdef HAVE_MALLOC_SIZE
 120     update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
 121     return ptr;
 122 #else
 123     *((size_t*)ptr) = size;
 124     update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
 125     return (char*)ptr+PREFIX_SIZE;
 126 #endif
 127 }
 128
 129 void *zrealloc(void *ptr, size_t size) {
 130 #ifndef HAVE_MALLOC_SIZE
 131     void *realptr;
 132 #endif
 133     size_t oldsize;
 134     void *newptr;
 135
 136     if (ptr == NULL) return zmalloc(size);
 137 #ifdef HAVE_MALLOC_SIZE
 138     oldsize = zmalloc_size(ptr);
 139     newptr = realloc(ptr,size);
 140     if (!newptr) zmalloc_oom(size);
 141
 142     update_zmalloc_stat_free(oldsize);
 143     update_zmalloc_stat_alloc(zmalloc_size(newptr),size);
 144     return newptr;
 145 #else
 146     realptr = (char*)ptr-PREFIX_SIZE;
 147     oldsize = *((size_t*)realptr);
 148     newptr = realloc(realptr,size+PREFIX_SIZE);
 149     if (!newptr) zmalloc_oom(size);
 150
 151     *((size_t*)newptr) = size;
 152     update_zmalloc_stat_free(oldsize);
 153     update_zmalloc_stat_alloc(size,size);
 154     return (char*)newptr+PREFIX_SIZE;
 155 #endif
 156 }
 157
 158 void zfree(void *ptr) {
 159 #ifndef HAVE_MALLOC_SIZE
 160     void *realptr;
 161     size_t oldsize;
 162 #endif
 163
 164     if (ptr == NULL) return;
 165 #ifdef HAVE_MALLOC_SIZE
 166     update_zmalloc_stat_free(zmalloc_size(ptr));
 167     free(ptr);
 168 #else
 169     realptr = (char*)ptr-PREFIX_SIZE;
 170     oldsize = *((size_t*)realptr);
 171     update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
 172     free(realptr);
 173 #endif
 174 }
 175
 176 char *zstrdup(const char *s) {
 177     size_t l = strlen(s)+1;
 178     char *p = zmalloc(l);
 179
 180     memcpy(p,s,l);
 181     return p;
 182 }
 183
 184 size_t zmalloc_used_memory(void) {
 185     size_t um;
 186
 187     if (zmalloc_thread_safe) pthread_mutex_lock(&used_memory_mutex);
 188     um = used_memory;
 189     if (zmalloc_thread_safe) pthread_mutex_unlock(&used_memory_mutex);
 190     return um;
 191 }
 192
 193 size_t zmalloc_allocations_for_size(size_t size) {
 194     if (size > ZMALLOC_MAX_ALLOC_STAT) return 0;
 195     return zmalloc_allocations[size];
 196 }
 197
 198 void zmalloc_enable_thread_safeness(void) {
 199     zmalloc_thread_safe = 1;
 200 }
 201
 202 /* Get the RSS information in an OS-specific way.
 203  *
 204  * WARNING: the function zmalloc_get_rss() is not designed to be fast
 205  * and may not be called in the busy loops where Redis tries to release
 206  * memory expiring or swapping out objects.
 207  *
 208  * For this kind of "fast RSS reporting" usages use instead the
 209  * function RedisEstimateRSS() that is a much faster (and less precise)
 210  * version of the funciton. */
 211
 212 #if defined(HAVE_PROCFS)
 213 #include <unistd.h>
 214 #include <sys/types.h>
 215 #include <sys/stat.h>
 216 #include <fcntl.h>
 217
 218 size_t zmalloc_get_rss(void) {
 219     int page = sysconf(_SC_PAGESIZE);
 220     size_t rss;
 221     char buf[4096];
 222     char filename[256];
 223     int fd, count;
 224     char *p, *x;
 225
 226     snprintf(filename,256,"/proc/%d/stat",getpid());
 227     if ((fd = open(filename,O_RDONLY)) == -1) return 0;
 228     if (read(fd,buf,4096) <= 0) {
 229         close(fd);
 230         return 0;
 231     }
 232     close(fd);
 233
 234     p = buf;
 235     count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
 236     while(p && count--) {
 237         p = strchr(p,' ');
 238         if (p) p++;
 239     }
 240     if (!p) return 0;
 241     x = strchr(p,' ');
 242     if (!x) return 0;
 243     *x = '\0';
 244
 245     rss = strtoll(p,NULL,10);
 246     rss *= page;
 247     return rss;
 248 }
 249 #elif defined(HAVE_TASKINFO)
 250 #include <unistd.h>
 251 #include <stdio.h>
 252 #include <stdlib.h>
 253 #include <sys/types.h>
 254 #include <sys/sysctl.h>
 255 #include <mach/task.h>
 256 #include <mach/mach_init.h>
 257
 258 size_t zmalloc_get_rss(void) {
 259     task_t task = MACH_PORT_NULL;
 260     struct task_basic_info t_info;
 261     mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
 262
 263     if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
 264         return 0;
 265     task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
 266
 267     return t_info.resident_size;
 268 }
 269 #else
 270 size_t zmalloc_get_rss(void) {
 271     /* If we can't get the RSS in an OS-specific way for this system just
 272      * return the memory usage we estimated in zmalloc()..
 273      *
 274      * Fragmentation will appear to be always 1 (no fragmentation)
 275      * of course... */
 276     return zmalloc_used_memory();
 277 }
 278 #endif
 279
 280 /* Fragmentation = RSS / allocated-bytes */
 281 float zmalloc_get_fragmentation_ratio(void) {
 282     return (float)zmalloc_get_rss()/zmalloc_used_memory();
 283 }