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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
34/* This function provide us access to the original libc free(). This is useful
35 * for instance to free results obtained by backtrace_symbols(). We need
36 * to define this function before including zmalloc.h that may shadow the
37 * free implementation if we use jemalloc or another non standard allocator. */
38void zlibc_free(void *ptr) {
39 free(ptr);
40}
41
42#include <string.h>
43#include <pthread.h>
44#include "config.h"
45#include "zmalloc.h"
46
47#ifdef HAVE_MALLOC_SIZE
48#define PREFIX_SIZE (0)
49#else
50#if defined(__sun) || defined(__sparc) || defined(__sparc__)
51#define PREFIX_SIZE (sizeof(long long))
52#else
53#define PREFIX_SIZE (sizeof(size_t))
54#endif
55#endif
56
57/* Explicitly override malloc/free etc when using tcmalloc. */
58#if defined(USE_TCMALLOC)
59#define malloc(size) tc_malloc(size)
60#define calloc(count,size) tc_calloc(count,size)
61#define realloc(ptr,size) tc_realloc(ptr,size)
62#define free(ptr) tc_free(ptr)
63#elif defined(USE_JEMALLOC)
64#define malloc(size) je_malloc(size)
65#define calloc(count,size) je_calloc(count,size)
66#define realloc(ptr,size) je_realloc(ptr,size)
67#define free(ptr) je_free(ptr)
68#endif
69
70#ifdef HAVE_ATOMIC
71#define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
72#define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
73#else
74#define update_zmalloc_stat_add(__n) do { \
75 pthread_mutex_lock(&used_memory_mutex); \
76 used_memory += (__n); \
77 pthread_mutex_unlock(&used_memory_mutex); \
78} while(0)
79
80#define update_zmalloc_stat_sub(__n) do { \
81 pthread_mutex_lock(&used_memory_mutex); \
82 used_memory -= (__n); \
83 pthread_mutex_unlock(&used_memory_mutex); \
84} while(0)
85
86#endif
87
88#define update_zmalloc_stat_alloc(__n,__size) do { \
89 size_t _n = (__n); \
90 if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
91 if (zmalloc_thread_safe) { \
92 update_zmalloc_stat_add(_n); \
93 } else { \
94 used_memory += _n; \
95 } \
96} while(0)
97
98#define update_zmalloc_stat_free(__n) do { \
99 size_t _n = (__n); \
100 if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
101 if (zmalloc_thread_safe) { \
102 update_zmalloc_stat_sub(_n); \
103 } else { \
104 used_memory -= _n; \
105 } \
106} while(0)
107
108static size_t used_memory = 0;
109static int zmalloc_thread_safe = 0;
110pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
111
112static void zmalloc_oom(size_t size) {
113 fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
114 size);
115 fflush(stderr);
116 abort();
117}
118
119void *zmalloc(size_t size) {
120 void *ptr = malloc(size+PREFIX_SIZE);
121
122 if (!ptr) zmalloc_oom(size);
123#ifdef HAVE_MALLOC_SIZE
124 update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
125 return ptr;
126#else
127 *((size_t*)ptr) = size;
128 update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
129 return (char*)ptr+PREFIX_SIZE;
130#endif
131}
132
133void *zcalloc(size_t size) {
134 void *ptr = calloc(1, size+PREFIX_SIZE);
135
136 if (!ptr) zmalloc_oom(size);
137#ifdef HAVE_MALLOC_SIZE
138 update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
139 return ptr;
140#else
141 *((size_t*)ptr) = size;
142 update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
143 return (char*)ptr+PREFIX_SIZE;
144#endif
145}
146
147void *zrealloc(void *ptr, size_t size) {
148#ifndef HAVE_MALLOC_SIZE
149 void *realptr;
150#endif
151 size_t oldsize;
152 void *newptr;
153
154 if (ptr == NULL) return zmalloc(size);
155#ifdef HAVE_MALLOC_SIZE
156 oldsize = zmalloc_size(ptr);
157 newptr = realloc(ptr,size);
158 if (!newptr) zmalloc_oom(size);
159
160 update_zmalloc_stat_free(oldsize);
161 update_zmalloc_stat_alloc(zmalloc_size(newptr),size);
162 return newptr;
163#else
164 realptr = (char*)ptr-PREFIX_SIZE;
165 oldsize = *((size_t*)realptr);
166 newptr = realloc(realptr,size+PREFIX_SIZE);
167 if (!newptr) zmalloc_oom(size);
168
169 *((size_t*)newptr) = size;
170 update_zmalloc_stat_free(oldsize);
171 update_zmalloc_stat_alloc(size,size);
172 return (char*)newptr+PREFIX_SIZE;
173#endif
174}
175
176/* Provide zmalloc_size() for systems where this function is not provided by
177 * malloc itself, given that in that case we store an header with this
178 * information as the first bytes of every allocation. */
179#ifndef HAVE_MALLOC_SIZE
180size_t zmalloc_size(void *ptr) {
181 void *realptr = (char*)ptr-PREFIX_SIZE;
182 size_t size = *((size_t*)realptr);
183 /* Assume at least that all the allocations are padded at sizeof(long) by
184 * the underlying allocator. */
185 if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1));
186 return size+PREFIX_SIZE;
187}
188#endif
189
190void zfree(void *ptr) {
191#ifndef HAVE_MALLOC_SIZE
192 void *realptr;
193 size_t oldsize;
194#endif
195
196 if (ptr == NULL) return;
197#ifdef HAVE_MALLOC_SIZE
198 update_zmalloc_stat_free(zmalloc_size(ptr));
199 free(ptr);
200#else
201 realptr = (char*)ptr-PREFIX_SIZE;
202 oldsize = *((size_t*)realptr);
203 update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
204 free(realptr);
205#endif
206}
207
208char *zstrdup(const char *s) {
209 size_t l = strlen(s)+1;
210 char *p = zmalloc(l);
211
212 memcpy(p,s,l);
213 return p;
214}
215
216size_t zmalloc_used_memory(void) {
217 size_t um;
218
219 if (zmalloc_thread_safe) {
220#ifdef HAVE_ATOMIC
221 um = __sync_add_and_fetch(&used_memory, 0);
222#else
223 pthread_mutex_lock(&used_memory_mutex);
224 um = used_memory;
225 pthread_mutex_unlock(&used_memory_mutex);
226#endif
227 }
228 else {
229 um = used_memory;
230 }
231
232 return um;
233}
234
235void zmalloc_enable_thread_safeness(void) {
236 zmalloc_thread_safe = 1;
237}
238
239/* Get the RSS information in an OS-specific way.
240 *
241 * WARNING: the function zmalloc_get_rss() is not designed to be fast
242 * and may not be called in the busy loops where Redis tries to release
243 * memory expiring or swapping out objects.
244 *
245 * For this kind of "fast RSS reporting" usages use instead the
246 * function RedisEstimateRSS() that is a much faster (and less precise)
247 * version of the funciton. */
248
249#if defined(HAVE_PROCFS)
250#include <unistd.h>
251#include <sys/types.h>
252#include <sys/stat.h>
253#include <fcntl.h>
254
255size_t zmalloc_get_rss(void) {
256 int page = sysconf(_SC_PAGESIZE);
257 size_t rss;
258 char buf[4096];
259 char filename[256];
260 int fd, count;
261 char *p, *x;
262
263 snprintf(filename,256,"/proc/%d/stat",getpid());
264 if ((fd = open(filename,O_RDONLY)) == -1) return 0;
265 if (read(fd,buf,4096) <= 0) {
266 close(fd);
267 return 0;
268 }
269 close(fd);
270
271 p = buf;
272 count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
273 while(p && count--) {
274 p = strchr(p,' ');
275 if (p) p++;
276 }
277 if (!p) return 0;
278 x = strchr(p,' ');
279 if (!x) return 0;
280 *x = '\0';
281
282 rss = strtoll(p,NULL,10);
283 rss *= page;
284 return rss;
285}
286#elif defined(HAVE_TASKINFO)
287#include <unistd.h>
288#include <stdio.h>
289#include <stdlib.h>
290#include <sys/types.h>
291#include <sys/sysctl.h>
292#include <mach/task.h>
293#include <mach/mach_init.h>
294
295size_t zmalloc_get_rss(void) {
296 task_t task = MACH_PORT_NULL;
297 struct task_basic_info t_info;
298 mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
299
300 if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
301 return 0;
302 task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
303
304 return t_info.resident_size;
305}
306#else
307size_t zmalloc_get_rss(void) {
308 /* If we can't get the RSS in an OS-specific way for this system just
309 * return the memory usage we estimated in zmalloc()..
310 *
311 * Fragmentation will appear to be always 1 (no fragmentation)
312 * of course... */
313 return zmalloc_used_memory();
314}
315#endif
316
317/* Fragmentation = RSS / allocated-bytes */
318float zmalloc_get_fragmentation_ratio(void) {
319 return (float)zmalloc_get_rss()/zmalloc_used_memory();
320}