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 #endif
  55
  56 #define update_zmalloc_stat_alloc(__n,__size) do { \
  57     size_t _n = (__n); \
  58     size_t _stat_slot = (__size < ZMALLOC_MAX_ALLOC_STAT) ? __size : ZMALLOC_MAX_ALLOC_STAT; \
  59     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  60     if (zmalloc_thread_safe) { \
  61         pthread_mutex_lock(&used_memory_mutex);  \
  62         used_memory += _n; \
  63         zmalloc_allocations[_stat_slot]++; \
  64         pthread_mutex_unlock(&used_memory_mutex); \
  65     } else { \
  66         used_memory += _n; \
  67         zmalloc_allocations[_stat_slot]++; \
  68     } \
  69 } while(0)
  70
  71 #define update_zmalloc_stat_free(__n) do { \
  72     size_t _n = (__n); \
  73     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  74     if (zmalloc_thread_safe) { \
  75         pthread_mutex_lock(&used_memory_mutex);  \
  76         used_memory -= _n; \
  77         pthread_mutex_unlock(&used_memory_mutex); \
  78     } else { \
  79         used_memory -= _n; \
  80     } \
  81 } while(0)
  82
  83 static size_t used_memory = 0;
  84 static int zmalloc_thread_safe = 0;
  85 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
  86 /* Note that malloc_allocations elements are initialized to zero by C */
  87 size_t zmalloc_allocations[ZMALLOC_MAX_ALLOC_STAT+1];
  88
  89 static void zmalloc_oom(size_t size) {
  90     fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
  91         size);
  92     fflush(stderr);
  93     abort();
  94 }
  95
  96 void *zmalloc(size_t size) {
  97     void *ptr = malloc(size+PREFIX_SIZE);
  98
  99     if (!ptr) zmalloc_oom(size);
 100 #ifdef HAVE_MALLOC_SIZE
 101     update_zmalloc_stat_alloc(redis_malloc_size(ptr),size);
 102     return ptr;
 103 #else
 104     *((size_t*)ptr) = size;
 105     update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
 106     return (char*)ptr+PREFIX_SIZE;
 107 #endif
 108 }
 109
 110 void *zcalloc(size_t size) {
 111     void *ptr = calloc(1, size+PREFIX_SIZE);
 112
 113     if (!ptr) zmalloc_oom(size);
 114 #ifdef HAVE_MALLOC_SIZE
 115     update_zmalloc_stat_alloc(redis_malloc_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 *zrealloc(void *ptr, size_t size) {
 125 #ifndef HAVE_MALLOC_SIZE
 126     void *realptr;
 127 #endif
 128     size_t oldsize;
 129     void *newptr;
 130
 131     if (ptr == NULL) return zmalloc(size);
 132 #ifdef HAVE_MALLOC_SIZE
 133     oldsize = redis_malloc_size(ptr);
 134     newptr = realloc(ptr,size);
 135     if (!newptr) zmalloc_oom(size);
 136
 137     update_zmalloc_stat_free(oldsize);
 138     update_zmalloc_stat_alloc(redis_malloc_size(newptr),size);
 139     return newptr;
 140 #else
 141     realptr = (char*)ptr-PREFIX_SIZE;
 142     oldsize = *((size_t*)realptr);
 143     newptr = realloc(realptr,size+PREFIX_SIZE);
 144     if (!newptr) zmalloc_oom(size);
 145
 146     *((size_t*)newptr) = size;
 147     update_zmalloc_stat_free(oldsize);
 148     update_zmalloc_stat_alloc(size,size);
 149     return (char*)newptr+PREFIX_SIZE;
 150 #endif
 151 }
 152
 153 void zfree(void *ptr) {
 154 #ifndef HAVE_MALLOC_SIZE
 155     void *realptr;
 156     size_t oldsize;
 157 #endif
 158
 159     if (ptr == NULL) return;
 160 #ifdef HAVE_MALLOC_SIZE
 161     update_zmalloc_stat_free(redis_malloc_size(ptr));
 162     free(ptr);
 163 #else
 164     realptr = (char*)ptr-PREFIX_SIZE;
 165     oldsize = *((size_t*)realptr);
 166     update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
 167     free(realptr);
 168 #endif
 169 }
 170
 171 char *zstrdup(const char *s) {
 172     size_t l = strlen(s)+1;
 173     char *p = zmalloc(l);
 174
 175     memcpy(p,s,l);
 176     return p;
 177 }
 178
 179 size_t zmalloc_used_memory(void) {
 180     size_t um;
 181
 182     if (zmalloc_thread_safe) pthread_mutex_lock(&used_memory_mutex);
 183     um = used_memory;
 184     if (zmalloc_thread_safe) pthread_mutex_unlock(&used_memory_mutex);
 185     return um;
 186 }
 187
 188 size_t zmalloc_allocations_for_size(size_t size) {
 189     if (size > ZMALLOC_MAX_ALLOC_STAT) return 0;
 190     return zmalloc_allocations[size];
 191 }
 192
 193 void zmalloc_enable_thread_safeness(void) {
 194     zmalloc_thread_safe = 1;
 195 }
 196
 197 /* Get the RSS information in an OS-specific way.
 198  *
 199  * WARNING: the function zmalloc_get_rss() is not designed to be fast
 200  * and may not be called in the busy loops where Redis tries to release
 201  * memory expiring or swapping out objects.
 202  *
 203  * For this kind of "fast RSS reporting" usages use instead the
 204  * function RedisEstimateRSS() that is a much faster (and less precise)
 205  * version of the funciton. */
 206
 207 #if defined(HAVE_PROCFS)
 208 #include <unistd.h>
 209 #include <sys/types.h>
 210 #include <sys/stat.h>
 211 #include <fcntl.h>
 212
 213 size_t zmalloc_get_rss(void) {
 214     int page = sysconf(_SC_PAGESIZE);
 215     size_t rss;
 216     char buf[4096];
 217     char filename[256];
 218     int fd, count;
 219     char *p, *x;
 220
 221     snprintf(filename,256,"/proc/%d/stat",getpid());
 222     if ((fd = open(filename,O_RDONLY)) == -1) return 0;
 223     if (read(fd,buf,4096) <= 0) {
 224         close(fd);
 225         return 0;
 226     }
 227     close(fd);
 228
 229     p = buf;
 230     count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
 231     while(p && count--) {
 232         p = strchr(p,' ');
 233         if (p) p++;
 234     }
 235     if (!p) return 0;
 236     x = strchr(p,' ');
 237     if (!x) return 0;
 238     *x = '\0';
 239
 240     rss = strtoll(p,NULL,10);
 241     rss *= page;
 242     return rss;
 243 }
 244 #elif defined(HAVE_TASKINFO)
 245 #include <unistd.h>
 246 #include <stdio.h>
 247 #include <stdlib.h>
 248 #include <sys/types.h>
 249 #include <sys/sysctl.h>
 250 #include <mach/task.h>
 251 #include <mach/mach_init.h>
 252
 253 size_t zmalloc_get_rss(void) {
 254     task_t task = MACH_PORT_NULL;
 255     struct task_basic_info t_info;
 256     mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
 257
 258     if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
 259         return 0;
 260     task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
 261
 262     return t_info.resident_size;
 263 }
 264 #else
 265 size_t zmalloc_get_rss(void) {
 266     /* If we can't get the RSS in an OS-specific way for this system just
 267      * return the memory usage we estimated in zmalloc()..
 268      *
 269      * Fragmentation will appear to be always 1 (no fragmentation)
 270      * of course... */
 271     return zmalloc_used_memory();
 272 }
 273 #endif
 274
 275 /* Fragmentation = RSS / allocated-bytes */
 276 float zmalloc_get_fragmentation_ratio(void) {
 277     return (float)zmalloc_get_rss()/zmalloc_used_memory();
 278 }