xref: /redis-3.2.3/src/zmalloc.c (revision 9a635431)
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. */
zlibc_free(void * ptr)38 void 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 #if defined(__ATOMIC_RELAXED)
71 #define update_zmalloc_stat_add(__n) __atomic_add_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
72 #define update_zmalloc_stat_sub(__n) __atomic_sub_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
73 #elif defined(HAVE_ATOMIC)
74 #define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
75 #define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
76 #else
77 #define update_zmalloc_stat_add(__n) do { \
78     pthread_mutex_lock(&used_memory_mutex); \
79     used_memory += (__n); \
80     pthread_mutex_unlock(&used_memory_mutex); \
81 } while(0)
82 
83 #define update_zmalloc_stat_sub(__n) do { \
84     pthread_mutex_lock(&used_memory_mutex); \
85     used_memory -= (__n); \
86     pthread_mutex_unlock(&used_memory_mutex); \
87 } while(0)
88 
89 #endif
90 
91 #define update_zmalloc_stat_alloc(__n) do { \
92     size_t _n = (__n); \
93     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
94     if (zmalloc_thread_safe) { \
95         update_zmalloc_stat_add(_n); \
96     } else { \
97         used_memory += _n; \
98     } \
99 } while(0)
100 
101 #define update_zmalloc_stat_free(__n) do { \
102     size_t _n = (__n); \
103     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
104     if (zmalloc_thread_safe) { \
105         update_zmalloc_stat_sub(_n); \
106     } else { \
107         used_memory -= _n; \
108     } \
109 } while(0)
110 
111 static size_t used_memory = 0;
112 static int zmalloc_thread_safe = 0;
113 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
114 
zmalloc_default_oom(size_t size)115 static void zmalloc_default_oom(size_t size) {
116     fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
117         size);
118     fflush(stderr);
119     abort();
120 }
121 
122 static void (*zmalloc_oom_handler)(size_t) = zmalloc_default_oom;
123 
zmalloc(size_t size)124 void *zmalloc(size_t size) {
125     void *ptr = malloc(size+PREFIX_SIZE);
126 
127     if (!ptr) zmalloc_oom_handler(size);
128 #ifdef HAVE_MALLOC_SIZE
129     update_zmalloc_stat_alloc(zmalloc_size(ptr));
130     return ptr;
131 #else
132     *((size_t*)ptr) = size;
133     update_zmalloc_stat_alloc(size+PREFIX_SIZE);
134     return (char*)ptr+PREFIX_SIZE;
135 #endif
136 }
137 
zcalloc(size_t size)138 void *zcalloc(size_t size) {
139     void *ptr = calloc(1, size+PREFIX_SIZE);
140 
141     if (!ptr) zmalloc_oom_handler(size);
142 #ifdef HAVE_MALLOC_SIZE
143     update_zmalloc_stat_alloc(zmalloc_size(ptr));
144     return ptr;
145 #else
146     *((size_t*)ptr) = size;
147     update_zmalloc_stat_alloc(size+PREFIX_SIZE);
148     return (char*)ptr+PREFIX_SIZE;
149 #endif
150 }
151 
zrealloc(void * ptr,size_t size)152 void *zrealloc(void *ptr, size_t size) {
153 #ifndef HAVE_MALLOC_SIZE
154     void *realptr;
155 #endif
156     size_t oldsize;
157     void *newptr;
158 
159     if (ptr == NULL) return zmalloc(size);
160 #ifdef HAVE_MALLOC_SIZE
161     oldsize = zmalloc_size(ptr);
162     newptr = realloc(ptr,size);
163     if (!newptr) zmalloc_oom_handler(size);
164 
165     update_zmalloc_stat_free(oldsize);
166     update_zmalloc_stat_alloc(zmalloc_size(newptr));
167     return newptr;
168 #else
169     realptr = (char*)ptr-PREFIX_SIZE;
170     oldsize = *((size_t*)realptr);
171     newptr = realloc(realptr,size+PREFIX_SIZE);
172     if (!newptr) zmalloc_oom_handler(size);
173 
174     *((size_t*)newptr) = size;
175     update_zmalloc_stat_free(oldsize);
176     update_zmalloc_stat_alloc(size);
177     return (char*)newptr+PREFIX_SIZE;
178 #endif
179 }
180 
181 /* Provide zmalloc_size() for systems where this function is not provided by
182  * malloc itself, given that in that case we store a header with this
183  * information as the first bytes of every allocation. */
184 #ifndef HAVE_MALLOC_SIZE
zmalloc_size(void * ptr)185 size_t zmalloc_size(void *ptr) {
186     void *realptr = (char*)ptr-PREFIX_SIZE;
187     size_t size = *((size_t*)realptr);
188     /* Assume at least that all the allocations are padded at sizeof(long) by
189      * the underlying allocator. */
190     if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1));
191     return size+PREFIX_SIZE;
192 }
193 #endif
194 
zfree(void * ptr)195 void zfree(void *ptr) {
196 #ifndef HAVE_MALLOC_SIZE
197     void *realptr;
198     size_t oldsize;
199 #endif
200 
201     if (ptr == NULL) return;
202 #ifdef HAVE_MALLOC_SIZE
203     update_zmalloc_stat_free(zmalloc_size(ptr));
204     free(ptr);
205 #else
206     realptr = (char*)ptr-PREFIX_SIZE;
207     oldsize = *((size_t*)realptr);
208     update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
209     free(realptr);
210 #endif
211 }
212 
zstrdup(const char * s)213 char *zstrdup(const char *s) {
214     size_t l = strlen(s)+1;
215     char *p = zmalloc(l);
216 
217     memcpy(p,s,l);
218     return p;
219 }
220 
zmalloc_used_memory(void)221 size_t zmalloc_used_memory(void) {
222     size_t um;
223 
224     if (zmalloc_thread_safe) {
225 #if defined(__ATOMIC_RELAXED) || defined(HAVE_ATOMIC)
226         um = update_zmalloc_stat_add(0);
227 #else
228         pthread_mutex_lock(&used_memory_mutex);
229         um = used_memory;
230         pthread_mutex_unlock(&used_memory_mutex);
231 #endif
232     }
233     else {
234         um = used_memory;
235     }
236 
237     return um;
238 }
239 
zmalloc_enable_thread_safeness(void)240 void zmalloc_enable_thread_safeness(void) {
241     zmalloc_thread_safe = 1;
242 }
243 
zmalloc_set_oom_handler(void (* oom_handler)(size_t))244 void zmalloc_set_oom_handler(void (*oom_handler)(size_t)) {
245     zmalloc_oom_handler = oom_handler;
246 }
247 
248 /* Get the RSS information in an OS-specific way.
249  *
250  * WARNING: the function zmalloc_get_rss() is not designed to be fast
251  * and may not be called in the busy loops where Redis tries to release
252  * memory expiring or swapping out objects.
253  *
254  * For this kind of "fast RSS reporting" usages use instead the
255  * function RedisEstimateRSS() that is a much faster (and less precise)
256  * version of the function. */
257 
258 #if defined(HAVE_PROC_STAT)
259 #include <unistd.h>
260 #include <sys/types.h>
261 #include <sys/stat.h>
262 #include <fcntl.h>
263 
zmalloc_get_rss(void)264 size_t zmalloc_get_rss(void) {
265     int page = sysconf(_SC_PAGESIZE);
266     size_t rss;
267     char buf[4096];
268     char filename[256];
269     int fd, count;
270     char *p, *x;
271 
272     snprintf(filename,256,"/proc/%d/stat",getpid());
273     if ((fd = open(filename,O_RDONLY)) == -1) return 0;
274     if (read(fd,buf,4096) <= 0) {
275         close(fd);
276         return 0;
277     }
278     close(fd);
279 
280     p = buf;
281     count = 23; /* RSS is the 24th field in /proc/<pid>/stat */
282     while(p && count--) {
283         p = strchr(p,' ');
284         if (p) p++;
285     }
286     if (!p) return 0;
287     x = strchr(p,' ');
288     if (!x) return 0;
289     *x = '\0';
290 
291     rss = strtoll(p,NULL,10);
292     rss *= page;
293     return rss;
294 }
295 #elif defined(HAVE_TASKINFO)
296 #include <unistd.h>
297 #include <stdio.h>
298 #include <stdlib.h>
299 #include <sys/types.h>
300 #include <sys/sysctl.h>
301 #include <mach/task.h>
302 #include <mach/mach_init.h>
303 
zmalloc_get_rss(void)304 size_t zmalloc_get_rss(void) {
305     task_t task = MACH_PORT_NULL;
306     struct task_basic_info t_info;
307     mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
308 
309     if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
310         return 0;
311     task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
312 
313     return t_info.resident_size;
314 }
315 #else
zmalloc_get_rss(void)316 size_t zmalloc_get_rss(void) {
317     /* If we can't get the RSS in an OS-specific way for this system just
318      * return the memory usage we estimated in zmalloc()..
319      *
320      * Fragmentation will appear to be always 1 (no fragmentation)
321      * of course... */
322     return zmalloc_used_memory();
323 }
324 #endif
325 
326 /* Fragmentation = RSS / allocated-bytes */
zmalloc_get_fragmentation_ratio(size_t rss)327 float zmalloc_get_fragmentation_ratio(size_t rss) {
328     return (float)rss/zmalloc_used_memory();
329 }
330 
331 /* Get the sum of the specified field (converted form kb to bytes) in
332  * /proc/self/smaps. The field must be specified with trailing ":" as it
333  * apperas in the smaps output.
334  *
335  * Example: zmalloc_get_smap_bytes_by_field("Rss:");
336  */
337 #if defined(HAVE_PROC_SMAPS)
zmalloc_get_smap_bytes_by_field(char * field)338 size_t zmalloc_get_smap_bytes_by_field(char *field) {
339     char line[1024];
340     size_t bytes = 0;
341     FILE *fp = fopen("/proc/self/smaps","r");
342     int flen = strlen(field);
343 
344     if (!fp) return 0;
345     while(fgets(line,sizeof(line),fp) != NULL) {
346         if (strncmp(line,field,flen) == 0) {
347             char *p = strchr(line,'k');
348             if (p) {
349                 *p = '\0';
350                 bytes += strtol(line+flen,NULL,10) * 1024;
351             }
352         }
353     }
354     fclose(fp);
355     return bytes;
356 }
357 #else
zmalloc_get_smap_bytes_by_field(char * field)358 size_t zmalloc_get_smap_bytes_by_field(char *field) {
359     ((void) field);
360     return 0;
361 }
362 #endif
363 
zmalloc_get_private_dirty(void)364 size_t zmalloc_get_private_dirty(void) {
365     return zmalloc_get_smap_bytes_by_field("Private_Dirty:");
366 }
367 
368 /* Returns the size of physical memory (RAM) in bytes.
369  * It looks ugly, but this is the cleanest way to achive cross platform results.
370  * Cleaned up from:
371  *
372  * http://nadeausoftware.com/articles/2012/09/c_c_tip_how_get_physical_memory_size_system
373  *
374  * Note that this function:
375  * 1) Was released under the following CC attribution license:
376  *    http://creativecommons.org/licenses/by/3.0/deed.en_US.
377  * 2) Was originally implemented by David Robert Nadeau.
378  * 3) Was modified for Redis by Matt Stancliff.
379  * 4) This note exists in order to comply with the original license.
380  */
zmalloc_get_memory_size(void)381 size_t zmalloc_get_memory_size(void) {
382 #if defined(__unix__) || defined(__unix) || defined(unix) || \
383     (defined(__APPLE__) && defined(__MACH__))
384 #if defined(CTL_HW) && (defined(HW_MEMSIZE) || defined(HW_PHYSMEM64))
385     int mib[2];
386     mib[0] = CTL_HW;
387 #if defined(HW_MEMSIZE)
388     mib[1] = HW_MEMSIZE;            /* OSX. --------------------- */
389 #elif defined(HW_PHYSMEM64)
390     mib[1] = HW_PHYSMEM64;          /* NetBSD, OpenBSD. --------- */
391 #endif
392     int64_t size = 0;               /* 64-bit */
393     size_t len = sizeof(size);
394     if (sysctl( mib, 2, &size, &len, NULL, 0) == 0)
395         return (size_t)size;
396     return 0L;          /* Failed? */
397 
398 #elif defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE)
399     /* FreeBSD, Linux, OpenBSD, and Solaris. -------------------- */
400     return (size_t)sysconf(_SC_PHYS_PAGES) * (size_t)sysconf(_SC_PAGESIZE);
401 
402 #elif defined(CTL_HW) && (defined(HW_PHYSMEM) || defined(HW_REALMEM))
403     /* DragonFly BSD, FreeBSD, NetBSD, OpenBSD, and OSX. -------- */
404     int mib[2];
405     mib[0] = CTL_HW;
406 #if defined(HW_REALMEM)
407     mib[1] = HW_REALMEM;        /* FreeBSD. ----------------- */
408 #elif defined(HW_PYSMEM)
409     mib[1] = HW_PHYSMEM;        /* Others. ------------------ */
410 #endif
411     unsigned int size = 0;      /* 32-bit */
412     size_t len = sizeof(size);
413     if (sysctl(mib, 2, &size, &len, NULL, 0) == 0)
414         return (size_t)size;
415     return 0L;          /* Failed? */
416 #endif /* sysctl and sysconf variants */
417 
418 #else
419     return 0L;          /* Unknown OS. */
420 #endif
421 }
422 
423 
424