Redisメモリ管理ソース分析
60316 ワード
Redisの最下位レベルのメモリ管理がどのように行われているかを知るには、ソースコードを直接見るのが絶対に良い選択です.
以下は私が詳細な注釈を追加したソースコードです.注意しなければならないのは、ソース分析を容易にするために、redisをプラットフォームの違いを補うためのコードの一部を削除しました.これがあればいいだけです.
以下私は2部のソースコードを貼ることができます:1部は私自身で、削除して注釈を追加したことがあって、一部は原生で、参考にして対照することができます
redisメモリ管理部のソースコードはzmalloc.hファイルとzmalloc.cファイル
推奨記事:
https://www.cnblogs.com/likui360/p/5272443.html
https://www.cnblogs.com/likui360/p/5272975.html
http://wiki.jikexueyuan.com/project/redis/memory-data-management.html
私のソース
zmalloc.h:
zmalloc.c:
オリジナルソース:
zmalloc.h:
zmalloc.c:
以下は私が詳細な注釈を追加したソースコードです.注意しなければならないのは、ソース分析を容易にするために、redisをプラットフォームの違いを補うためのコードの一部を削除しました.これがあればいいだけです.
以下私は2部のソースコードを貼ることができます:1部は私自身で、削除して注釈を追加したことがあって、一部は原生で、参考にして対照することができます
redisメモリ管理部のソースコードはzmalloc.hファイルとzmalloc.cファイル
推奨記事:
https://www.cnblogs.com/likui360/p/5272443.html
https://www.cnblogs.com/likui360/p/5272975.html
http://wiki.jikexueyuan.com/project/redis/memory-data-management.html
私のソース
zmalloc.h:
#ifndef __ZMALLOC_H
#define __ZMALLOC_H
#define __xstr(s) __str(s)
#define __str(s) #s
#ifndef ZMALLOC_LIB
#define ZMALLOC_LIB "libc"
#endif
/*
CPU ， 32 （ 4 ）、64 （ 8 ） 。
8 ， 8 。
（CPU） long ， ， ，
8 。
8 64 ， 32 4 。
Redis ， 。
sizeof(long) sizeof(size_t) 。
size_t（gcc long unsigned int） long ，
long 。
（long ） 8 ， 。
*/
/**
Redis :
|--------|: 8
| | |
|--------|--------|--------|--------|--------|
^
|
ptr:
：
1. , 8 ， cpu
2.
ps: ,
*/
//============ API ==================//
// malloc,
void *zmalloc(size_t size);
// calloc,
void *zcalloc(size_t size);
// realloc,
void *zrealloc(void *ptr, size_t size);
// free, ， ， ，
void zfree(void *ptr);
// ,
char *zstrdup(const char *s);
//
size_t zmalloc_used_memory(void);
// ， mutex
void zmalloc_enable_thread_safeness(void);
//
void zmalloc_set_oom_handler(void (*oom_handler)(size_t));
// , /
float zmalloc_get_fragmentation_ratio(size_t rss);
//
size_t zmalloc_get_rss(void);
// private_dirty
size_t zmalloc_get_private_dirty(void);
// ， 。
void zlibc_free(void *ptr);
//
size_t zmalloc_size(void *ptr);
#endif /* __ZMALLOC_H */
/*
1.malloc calloc
void *malloc(unsigned int size) size
void* calloc（unsigned int num，unsigned int size） num size
malloc
calloc 0， calloc
2.redis ， ， size ，size
3.Redis :jemalloc,tcmalloc, malloc， malloc
， ，
jemalloc freebsd ， ，
tcmalloc ，
4.Redis ，
5.memory aware【 】
Redis ， Redis ，
：
/
6. ， 5 8 ,CPU , 2 ， cpu
*/zmalloc.c:
#include
#include
#include <string.h>
#include
#include "zmalloc.h"
//
static size_t used_memory = 0;
//
static int zmalloc_thread_safe = 0;
// ， ， ，
pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
//
#define PREFIX_SIZE (sizeof(size_t))
//
#define update_zmalloc_stat_add(__n) do { \
pthread_mutex_lock(&used_memory_mutex); \
used_memory += (__n); \
pthread_mutex_unlock(&used_memory_mutex); \
} while(0)
//
#define update_zmalloc_stat_sub(__n) do { \
pthread_mutex_lock(&used_memory_mutex); \
used_memory -= (__n); \
pthread_mutex_unlock(&used_memory_mutex); \
} while(0)
// ,
#define update_zmalloc_stat_alloc(__n) do { \
size_t _n = (__n); \
if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1));/* */ \
if (zmalloc_thread_safe) { \
update_zmalloc_stat_add(_n); \
} else { \
used_memory += _n; \
} \
} while(0)
// ,
#define update_zmalloc_stat_free(__n) do { \
size_t _n = (__n); \
if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); /* */ \
if (zmalloc_thread_safe) { \
update_zmalloc_stat_sub(_n); \
} else { \
used_memory -= _n; \
} \
} while(0)
// ，
void zlibc_free(void *ptr)
{
free(ptr);
}
// OOM:out of memory
static void zmalloc_default_oom(size_t size)
{
fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes
",
size);
fflush(stderr);
abort();
}
// OMM
static void (*zmalloc_oom_handler)(size_t) = zmalloc_default_oom;
// size ，
void *zmalloc(size_t size)
{
// ， PREFIX_SIZE
void *ptr = malloc(size+PREFIX_SIZE);
//oom out of memory
if (!ptr) zmalloc_oom_handler(size); // ,
//
*((size_t*)ptr) = size;
//
update_zmalloc_stat_alloc(size+PREFIX_SIZE);
// ，
return (char*)ptr+PREFIX_SIZE;
}
//
void *zcalloc(size_t size)
{
//
void *ptr = calloc(1, size+PREFIX_SIZE);
// ，
if (!ptr) zmalloc_oom_handler(size);
*((size_t*)ptr) = size;
//
update_zmalloc_stat_alloc(size+PREFIX_SIZE);
//
return (char*)ptr+PREFIX_SIZE;
}
// size ，
void *zrealloc(void *ptr, size_t size)
{
void *realptr;
size_t oldsize;
void *newptr;
// ，
if (ptr == NULL) return zmalloc(size);
// ( )
realptr = (char*)ptr-PREFIX_SIZE;
// ( )
oldsize = *((size_t*)realptr);
// zrealloc realloc, size+PREFIX_SIZE
newptr = realloc(realptr,size+PREFIX_SIZE);
// ，
if (!newptr) zmalloc_oom_handler(size);
//
*((size_t*)newptr) = size;
//
update_zmalloc_stat_free(oldsize);
update_zmalloc_stat_alloc(size);
// ( )
return (char*)newptr+PREFIX_SIZE;
}
// ( )
size_t zmalloc_size(void *ptr)
{
// ( )
void *realptr = (char*)ptr-PREFIX_SIZE;
//
size_t size = *((size_t*)realptr);
// ， 5 8 ,CPU , 2 ， cpu
if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1));
// ( )
return size+PREFIX_SIZE;
}
// ，
void zfree(void *ptr)
{
/* ， */
void *realptr;
size_t oldsize;
//
if (ptr == NULL) return;
// ( )
realptr = (char*)ptr-PREFIX_SIZE;
//
oldsize = *((size_t*)realptr);
//
update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
//
free(realptr);
}
//
char *zstrdup(const char *s)
{
size_t l = strlen(s)+1;
char *p = zmalloc(l);
memcpy(p,s,l);
return p;
}
//
size_t zmalloc_used_memory(void)
{
size_t um;
//
if (zmalloc_thread_safe)
{
pthread_mutex_lock(&used_memory_mutex);
um = used_memory;
pthread_mutex_unlock(&used_memory_mutex);
}
else
{
um = used_memory;
}
return um;
}
// ,
void zmalloc_enable_thread_safeness(void)
{
zmalloc_thread_safe = 1;
}
// OMM
void zmalloc_set_oom_handler(void (*oom_handler)(size_t))
{
zmalloc_oom_handler = oom_handler;
}
//
//
size_t zmalloc_get_rss(void)
{
// .....
return zmalloc_used_memory();
}
//
float zmalloc_get_fragmentation_ratio(size_t rss)
{
return (float)rss/zmalloc_used_memory();
}
// private_dirty
size_t zmalloc_get_private_dirty(void)
{
return 0;
} オリジナルソース:
zmalloc.h:
/* zmalloc - total amount of allocated memory aware version of malloc()
*
* Copyright (c) 2009-2010, Salvatore Sanfilippo
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __ZMALLOC_H
#define __ZMALLOC_H
/* Double expansion needed for stringification of macro values. */
#define __xstr(s) __str(s)
#define __str(s) #s
#if defined(USE_TCMALLOC)
#define ZMALLOC_LIB ("tcmalloc-" __xstr(TC_VERSION_MAJOR) "." __xstr(TC_VERSION_MINOR))
#include
#if (TC_VERSION_MAJOR == 1 && TC_VERSION_MINOR >= 6) || (TC_VERSION_MAJOR > 1)
#define HAVE_MALLOC_SIZE 1
#define zmalloc_size(p) tc_malloc_size(p)
#else
#error "Newer version of tcmalloc required"
#endif
#elif defined(USE_JEMALLOC)
#define ZMALLOC_LIB ("jemalloc-" __xstr(JEMALLOC_VERSION_MAJOR) "." __xstr(JEMALLOC_VERSION_MINOR) "." __xstr(JEMALLOC_VERSION_BUGFIX))
#include
#if (JEMALLOC_VERSION_MAJOR == 2 && JEMALLOC_VERSION_MINOR >= 1) || (JEMALLOC_VERSION_MAJOR > 2)
#define HAVE_MALLOC_SIZE 1
#define zmalloc_size(p) je_malloc_usable_size(p)
#else
#error "Newer version of jemalloc required"
#endif
#elif defined(__APPLE__)
#include <malloc/malloc.h>
#define HAVE_MALLOC_SIZE 1
#define zmalloc_size(p) malloc_size(p)
#endif
#ifndef ZMALLOC_LIB
#define ZMALLOC_LIB "libc"
#endif
void *zmalloc(size_t size);
void *zcalloc(size_t size);
void *zrealloc(void *ptr, size_t size);
void zfree(void *ptr);
char *zstrdup(const char *s);
size_t zmalloc_used_memory(void);
void zmalloc_enable_thread_safeness(void);
void zmalloc_set_oom_handler(void (*oom_handler)(size_t));
float zmalloc_get_fragmentation_ratio(size_t rss);
size_t zmalloc_get_rss(void);
size_t zmalloc_get_private_dirty(void);
void zlibc_free(void *ptr);
#ifndef HAVE_MALLOC_SIZE
size_t zmalloc_size(void *ptr);
#endif
#endif /* __ZMALLOC_H */ zmalloc.c:
/* zmalloc - total amount of allocated memory aware version of malloc()
*
* Copyright (c) 2009-2010, Salvatore Sanfilippo
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include
#include
/* This function provide us access to the original libc free(). This is useful
* for instance to free results obtained by backtrace_symbols(). We need
* to define this function before including zmalloc.h that may shadow the
* free implementation if we use jemalloc or another non standard allocator. */
void zlibc_free(void *ptr) {
free(ptr);
}
#include <string.h>
#include
#include "config.h"
#include "zmalloc.h"
#ifdef HAVE_MALLOC_SIZE
#define PREFIX_SIZE (0)
#else
#if defined(__sun) || defined(__sparc) || defined(__sparc__)
#define PREFIX_SIZE (sizeof(long long))
#else
#define PREFIX_SIZE (sizeof(size_t))
#endif
#endif
/* Explicitly override malloc/free etc when using tcmalloc. */
#if defined(USE_TCMALLOC)
#define malloc(size) tc_malloc(size)
#define calloc(count,size) tc_calloc(count,size)
#define realloc(ptr,size) tc_realloc(ptr,size)
#define free(ptr) tc_free(ptr)
#elif defined(USE_JEMALLOC)
#define malloc(size) je_malloc(size)
#define calloc(count,size) je_calloc(count,size)
#define realloc(ptr,size) je_realloc(ptr,size)
#define free(ptr) je_free(ptr)
#endif
#ifdef HAVE_ATOMIC
#define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
#define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
#else
#define update_zmalloc_stat_add(__n) do { \
pthread_mutex_lock(&used_memory_mutex); \
used_memory += (__n); \
pthread_mutex_unlock(&used_memory_mutex); \
} while(0)
#define update_zmalloc_stat_sub(__n) do { \
pthread_mutex_lock(&used_memory_mutex); \
used_memory -= (__n); \
pthread_mutex_unlock(&used_memory_mutex); \
} while(0)
#endif
#define update_zmalloc_stat_alloc(__n) do { \
size_t _n = (__n); \
if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
if (zmalloc_thread_safe) { \
update_zmalloc_stat_add(_n); \
} else { \
used_memory += _n; \
} \
} while(0)
#define update_zmalloc_stat_free(__n) do { \
size_t _n = (__n); \
if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
if (zmalloc_thread_safe) { \
update_zmalloc_stat_sub(_n); \
} else { \
used_memory -= _n; \
} \
} while(0)
static size_t used_memory = 0;
static int zmalloc_thread_safe = 0;
pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
static void zmalloc_default_oom(size_t size) {
fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes
",
size);
fflush(stderr);
abort();
}
static void (*zmalloc_oom_handler)(size_t) = zmalloc_default_oom;
void *zmalloc(size_t size) {
void *ptr = malloc(size+PREFIX_SIZE);
if (!ptr) zmalloc_oom_handler(size);
#ifdef HAVE_MALLOC_SIZE
update_zmalloc_stat_alloc(zmalloc_size(ptr));
return ptr;
#else
*((size_t*)ptr) = size;
update_zmalloc_stat_alloc(size+PREFIX_SIZE);
return (char*)ptr+PREFIX_SIZE;
#endif
}
void *zcalloc(size_t size) {
void *ptr = calloc(1, size+PREFIX_SIZE);
if (!ptr) zmalloc_oom_handler(size);
#ifdef HAVE_MALLOC_SIZE
update_zmalloc_stat_alloc(zmalloc_size(ptr));
return ptr;
#else
*((size_t*)ptr) = size;
update_zmalloc_stat_alloc(size+PREFIX_SIZE);
return (char*)ptr+PREFIX_SIZE;
#endif
}
void *zrealloc(void *ptr, size_t size) {
#ifndef HAVE_MALLOC_SIZE
void *realptr;
#endif
size_t oldsize;
void *newptr;
if (ptr == NULL) return zmalloc(size);
#ifdef HAVE_MALLOC_SIZE
oldsize = zmalloc_size(ptr);
newptr = realloc(ptr,size);
if (!newptr) zmalloc_oom_handler(size);
update_zmalloc_stat_free(oldsize);
update_zmalloc_stat_alloc(zmalloc_size(newptr));
return newptr;
#else
realptr = (char*)ptr-PREFIX_SIZE;
oldsize = *((size_t*)realptr);
newptr = realloc(realptr,size+PREFIX_SIZE);
if (!newptr) zmalloc_oom_handler(size);
*((size_t*)newptr) = size;
update_zmalloc_stat_free(oldsize);
update_zmalloc_stat_alloc(size);
return (char*)newptr+PREFIX_SIZE;
#endif
}
/* Provide zmalloc_size() for systems where this function is not provided by
* malloc itself, given that in that case we store a header with this
* information as the first bytes of every allocation. */
#ifndef HAVE_MALLOC_SIZE
size_t zmalloc_size(void *ptr) {
void *realptr = (char*)ptr-PREFIX_SIZE;
size_t size = *((size_t*)realptr);
/* Assume at least that all the allocations are padded at sizeof(long) by
* the underlying allocator. */
if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1));
return size+PREFIX_SIZE;
}
#endif
void zfree(void *ptr) {
#ifndef HAVE_MALLOC_SIZE
void *realptr;
size_t oldsize;
#endif
if (ptr == NULL) return;
#ifdef HAVE_MALLOC_SIZE
update_zmalloc_stat_free(zmalloc_size(ptr));
free(ptr);
#else
realptr = (char*)ptr-PREFIX_SIZE;
oldsize = *((size_t*)realptr);
update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
free(realptr);
#endif
}
char *zstrdup(const char *s) {
size_t l = strlen(s)+1;
char *p = zmalloc(l);
memcpy(p,s,l);
return p;
}
size_t zmalloc_used_memory(void) {
size_t um;
if (zmalloc_thread_safe) {
#ifdef HAVE_ATOMIC
um = __sync_add_and_fetch(&used_memory, 0);
#else
pthread_mutex_lock(&used_memory_mutex);
um = used_memory;
pthread_mutex_unlock(&used_memory_mutex);
#endif
}
else {
um = used_memory;
}
return um;
}
void zmalloc_enable_thread_safeness(void) {
zmalloc_thread_safe = 1;
}
void zmalloc_set_oom_handler(void (*oom_handler)(size_t)) {
zmalloc_oom_handler = oom_handler;
}
/* Get the RSS information in an OS-specific way.
*
* WARNING: the function zmalloc_get_rss() is not designed to be fast
* and may not be called in the busy loops where Redis tries to release
* memory expiring or swapping out objects.
*
* For this kind of "fast RSS reporting" usages use instead the
* function RedisEstimateRSS() that is a much faster (and less precise)
* version of the function. */
#if defined(HAVE_PROC_STAT)
#include
#include
#include
#include
size_t zmalloc_get_rss(void) {
int page = sysconf(_SC_PAGESIZE);
size_t rss;
char buf[4096];
char filename[256];
int fd, count;
char *p, *x;
snprintf(filename,256,"/proc/%d/stat",getpid());
if ((fd = open(filename,O_RDONLY)) == -1) return 0;
if (read(fd,buf,4096) <= 0) {
close(fd);
return 0;
}
close(fd);
p = buf;
count = 23; /* RSS is the 24th field in /proc//stat */
while(p && count--) {
p = strchr(p,' ');
if (p) p++;
}
if (!p) return 0;
x = strchr(p,' ');
if (!x) return 0;
*x = '\0';
rss = strtoll(p,NULL,10);
rss *= page;
return rss;
}
#elif defined(HAVE_TASKINFO)
#include
#include
#include
#include
#include
#include
#include
size_t zmalloc_get_rss(void) {
task_t task = MACH_PORT_NULL;
struct task_basic_info t_info;
mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS)
return 0;
task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
return t_info.resident_size;
}
#else
size_t zmalloc_get_rss(void) {
/* If we can't get the RSS in an OS-specific way for this system just
* return the memory usage we estimated in zmalloc()..
*
* Fragmentation will appear to be always 1 (no fragmentation)
* of course... */
return zmalloc_used_memory();
}
#endif
/* Fragmentation = RSS / allocated-bytes */
float zmalloc_get_fragmentation_ratio(size_t rss) {
return (float)rss/zmalloc_used_memory();
}
#if defined(HAVE_PROC_SMAPS)
size_t zmalloc_get_private_dirty(void) {
char line[1024];
size_t pd = 0;
FILE *fp = fopen("/proc/self/smaps","r");
if (!fp) return 0;
while(fgets(line,sizeof(line),fp) != NULL) {
if (strncmp(line,"Private_Dirty:",14) == 0) {
char *p = strchr(line,'k');
if (p) {
*p = '\0';
pd += strtol(line+14,NULL,10) * 1024;
}
}
}
fclose(fp);
return pd;
}
#else
size_t zmalloc_get_private_dirty(void) {
return 0;
}
#endif