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