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 #define update_zmalloc_stat_alloc(__n,__size) do { \
  62     size_t _n = (__n); \
  63     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  64     if (zmalloc_thread_safe) { \
  65         pthread_mutex_lock(&used_memory_mutex);  \
  66         used_memory += _n; \
  67         pthread_mutex_unlock(&used_memory_mutex); \
  68     } else { \
  69         used_memory += _n; \
  70     } \
  71 } while(0)
  72
  73 #define update_zmalloc_stat_free(__n) do { \
  74     size_t _n = (__n); \
  75     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
  76     if (zmalloc_thread_safe) { \
  77         pthread_mutex_lock(&used_memory_mutex);  \
  78         used_memory -= _n; \
  79         pthread_mutex_unlock(&used_memory_mutex); \
  80     } else { \
  81         used_memory -= _n; \
  82     } \
  83 } while(0)
  84
  85 static size_t used_memory = 0;
  86 static int zmalloc_thread_safe = 0;
  87 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
  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(zmalloc_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(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 *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 = zmalloc_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(zmalloc_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 /* Provide zmalloc_size() for systems where this function is not provided by
 154  * malloc itself, given that in that case we store an header with this
 155  * information as the first bytes of every allocation. */
 156 #ifndef HAVE_MALLOC_SIZE
 157 size_t zmalloc_size(void *ptr) {
 158     void *realptr = (char*)ptr-PREFIX_SIZE;
 159     size_t size = *((size_t*)realptr);
 160     /* Assume at least that all the allocations are padded at sizeof(long) by
 161      * the underlying allocator. */
 162     if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1));
 163     return size+PREFIX_SIZE;
 164 }
 165 #endif
 166
 167 void zfree(void *ptr) {
 168 #ifndef HAVE_MALLOC_SIZE
 169     void *realptr;
 170     size_t oldsize;
 171 #endif
 172
 173     if (ptr == NULL) return;
 174 #ifdef HAVE_MALLOC_SIZE
 175     update_zmalloc_stat_free(zmalloc_size(ptr));
 176     free(ptr);
 177 #else
 178     realptr = (char*)ptr-PREFIX_SIZE;
 179     oldsize = *((size_t*)realptr);
 180     update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
 181     free(realptr);
 182 #endif
 183 }
 184
 185 char *zstrdup(const char *s) {
 186     size_t l = strlen(s)+1;
 187     char *p = zmalloc(l);
 188
 189     memcpy(p,s,l);
 190     return p;
 191 }
 192
 193 size_t zmalloc_used_memory(void) {
 194     size_t um;
 195
 196     if (zmalloc_thread_safe) pthread_mutex_lock(&used_memory_mutex);
 197     um = used_memory;
 198     if (zmalloc_thread_safe) pthread_mutex_unlock(&used_memory_mutex);
 199     return um;
 200 }
 201
 202 void zmalloc_enable_thread_safeness(void) {
 203     zmalloc_thread_safe = 1;
 204 }
 205
 206 /* Get the RSS information in an OS-specific way.
 207  *
 208  * WARNING: the function zmalloc_get_rss() is not designed to be fast
 209  * and may not be called in the busy loops where Redis tries to release
 210  * memory expiring or swapping out objects.
 211  *
 212  * For this kind of "fast RSS reporting" usages use instead the
 213  * function RedisEstimateRSS() that is a much faster (and less precise)
 214  * version of the funciton. */
 215
 216 #if defined(HAVE_PROCFS)
 217 #include <unistd.h>
 218 #include <sys/types.h>
 219 #include <sys/stat.h>
 220 #include <fcntl.h>
 221
 222 size_t zmalloc_get_rss(void) {
 223     int page = sysconf(_SC_PAGESIZE);
 224     size_t rss;
 225     char buf[4096];
 226     char filename[256];
 227     int fd, count;
 228     char *p, *x;
 229
 230     snprintf(filename,256,"/proc/%d/stat",getpid());
 231     if ((fd = open(filename,O_RDONLY)) == -1) return 0;
 232     if (read(fd,buf,4096) <= 0) {
 233         close(fd);
 234         return 0;
 235     }
 236     close(fd);
 237
 238     p = buf;
 239     count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
 240     while(p && count--) {
 241         p = strchr(p,' ');
 242         if (p) p++;
 243     }
 244     if (!p) return 0;
 245     x = strchr(p,' ');
 246     if (!x) return 0;
 247     *x = '\0';
 248
 249     rss = strtoll(p,NULL,10);
 250     rss *= page;
 251     return rss;
 252 }
 253 #elif defined(HAVE_TASKINFO)
 254 #include <unistd.h>
 255 #include <stdio.h>
 256 #include <stdlib.h>
 257 #include <sys/types.h>
 258 #include <sys/sysctl.h>
 259 #include <mach/task.h>
 260 #include <mach/mach_init.h>
 261
 262 size_t zmalloc_get_rss(void) {
 263     task_t task = MACH_PORT_NULL;
 264     struct task_basic_info t_info;
 265     mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
 266
 267     if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
 268         return 0;
 269     task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
 270
 271     return t_info.resident_size;
 272 }
 273 #else
 274 size_t zmalloc_get_rss(void) {
 275     /* If we can't get the RSS in an OS-specific way for this system just
 276      * return the memory usage we estimated in zmalloc()..
 277      *
 278      * Fragmentation will appear to be always 1 (no fragmentation)
 279      * of course... */
 280     return zmalloc_used_memory();
 281 }
 282 #endif
 283
 284 /* Fragmentation = RSS / allocated-bytes */
 285 float zmalloc_get_fragmentation_ratio(void) {
 286     return (float)zmalloc_get_rss()/zmalloc_used_memory();
 287 }