This repo fork from reed-lau, thanks to him for make it more better!
a nginx-based memory pool .
both share-memory and private-memory are supported. it is more efficient than malloc.
it is a very light weight and do not rely on any third-party library.
#include "ncx_slab.h"
int main(int argc, char **argv)
{
char *p;
size_t pool_size = 4096000; //4M
ncx_slab_stat_t stat;
u_char *space;
space = (u_char *)malloc(pool_size);
ncx_slab_pool_t *sp;
sp = (ncx_slab_pool_t*) space;
sp->addr = space;
sp->min_shift = 3;
sp->end = space + pool_size;
/*
* init
*/
ncx_slab_init(sp);
/*
* alloc
*/
p = ncx_slab_alloc(sp, 128);
/*
* memory usage api.
* note: this is optional. call it if you want to see memory usage status.
*/
ncx_slab_stat(sp, &stat);
/*
* free
*/
ncx_slab_free(sp, p);
free(space);
return 0;
}
void ncx_slab_init(ncx_slab_pool_t *pool)
Description: 初始化内存池结构;
void *ncx_slab_alloc(ncx_slab_pool_t *pool, size_t size)
Description: 内存分配
void ncx_slab_free(ncx_slab_pool_t *pool, void *ptr)
Description: 释放内存
void ncx_slab_stat(ncx_slab_pool_t *pool, ncx_slab_stat_t *stat)
Description: 查看内存池使用情况,(通过log接口打印)
正如example所示,内存池内存是由应用层先分配,ncx_mempool是在给定的内存基础上进行分配和回收管理。
所以内存池本身不关心所管理的内存是私有内存 or 共享内存;
ncx_lock.h 是锁接口;根据实际需要重定义:
- 多线程共享内存池,可参考pthread_spin_lock
- 多进程共享内存池,可参考nginx的ngx_shmtx.c实现spin lock
- 单进程单线程使用内存池,无锁编程..
ncx_log.h 是日志接口,根据实际需要重定义.
ncx_slab.c.orz 是 ncx_slab.c的详细注释,方便理解.
注意: 在使用的时候请务必添加-O2或或-Os或-O3编译参数进行代码优化,否则效率可能还不如malloc/free. 在调试阶段,可以使用-O0编译参数,方便跟踪调试。
This module is licensed under the BSD license. Copyright (C) 2013, by dcshi(施俊伟). [email protected] All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
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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.
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