潍坊寿光网站建设,google官网入口,制作主页的软件,.net做的网站打开速度缓慢文章目录 一、Nginx 的相关组件介绍1.1、ngx_palloc相关源码1.2、ngx_array组件的相关源码1.3、ngx_array的数据结构1.4、ngx_cycle简介和相关源码1.5、ngx_list相关源码1.6、ngx_list 的数据结构 二、Nginx 组件的使用2.1、makefile的编写2.2、ngx_pallocngx_array的使用2.3、… 文章目录 一、Nginx 的相关组件介绍1.1、ngx_palloc相关源码1.2、ngx_array组件的相关源码1.3、ngx_array的数据结构1.4、ngx_cycle简介和相关源码1.5、ngx_list相关源码1.6、ngx_list 的数据结构 二、Nginx 组件的使用2.1、makefile的编写2.2、ngx_pallocngx_array的使用2.3、ngx_pallocngx_list的使用 总结 一、Nginx 的相关组件介绍
Nginx自己实现了一个内存池组件。Nginx作为服务器当客户端 TCP连接 HTTP请求 到来时Nginx会为该连接创建一个专属的内存池这个内存池的生命周期是连接建立时创建连接断开时销毁。客户端和Nginx通信的所有数据和操作HTTP协议解析、HTTP数据解析等都在内存池中完成。
1.1、ngx_palloc相关源码
/src/core/ngx_palloc.h。相关实现在/src/core/ngx_palloc.c文件 #ifndef _NGX_PALLOC_H_INCLUDED_
#define _NGX_PALLOC_H_INCLUDED_#include ngx_config.h
#include ngx_core.h/** NGX_MAX_ALLOC_FROM_POOL should be (ngx_pagesize - 1), i.e. 4095 on x86.* On Windows NT it decreases a number of locked pages in a kernel.*/
#define NGX_MAX_ALLOC_FROM_POOL (ngx_pagesize - 1)#define NGX_DEFAULT_POOL_SIZE (16 * 1024)#define NGX_POOL_ALIGNMENT 16
#define NGX_MIN_POOL_SIZE \ngx_align((sizeof(ngx_pool_t) 2 * sizeof(ngx_pool_large_t)), \NGX_POOL_ALIGNMENT)typedef void (*ngx_pool_cleanup_pt)(void *data);typedef struct ngx_pool_cleanup_s ngx_pool_cleanup_t;struct ngx_pool_cleanup_s {ngx_pool_cleanup_pt handler;void *data;ngx_pool_cleanup_t *next;
};typedef struct ngx_pool_large_s ngx_pool_large_t;struct ngx_pool_large_s {ngx_pool_large_t *next;void *alloc;
};typedef struct {u_char *last;u_char *end;ngx_pool_t *next;ngx_uint_t failed;
} ngx_pool_data_t;struct ngx_pool_s {ngx_pool_data_t d;size_t max;ngx_pool_t *current;ngx_chain_t *chain;ngx_pool_large_t *large;ngx_pool_cleanup_t *cleanup;ngx_log_t *log;
};typedef struct {ngx_fd_t fd;u_char *name;ngx_log_t *log;
} ngx_pool_cleanup_file_t;ngx_pool_t *ngx_create_pool(size_t size, ngx_log_t *log);
void ngx_destroy_pool(ngx_pool_t *pool);
void ngx_reset_pool(ngx_pool_t *pool);void *ngx_palloc(ngx_pool_t *pool, size_t size);
void *ngx_pnalloc(ngx_pool_t *pool, size_t size);
void *ngx_pcalloc(ngx_pool_t *pool, size_t size);
void *ngx_pmemalign(ngx_pool_t *pool, size_t size, size_t alignment);
ngx_int_t ngx_pfree(ngx_pool_t *pool, void *p);ngx_pool_cleanup_t *ngx_pool_cleanup_add(ngx_pool_t *p, size_t size);
void ngx_pool_run_cleanup_file(ngx_pool_t *p, ngx_fd_t fd);
void ngx_pool_cleanup_file(void *data);
void ngx_pool_delete_file(void *data);#endif /* _NGX_PALLOC_H_INCLUDED_ *//src/core/ngx_palloc.c
void *
ngx_array_push(ngx_array_t *a)
{void *elt, *new;size_t size;ngx_pool_t *p;if (a-nelts a-nalloc) {/* the array is full */size a-size * a-nalloc;p a-pool;if ((u_char *) a-elts size p-d.last p-d.last a-size p-d.end){/** the array allocation is the last in the pool* and there is space for new allocation*/p-d.last a-size;a-nalloc;} else {/* allocate a new array */new ngx_palloc(p, 2 * size);if (new NULL) {return NULL;}ngx_memcpy(new, a-elts, size);a-elts new;a-nalloc * 2;}}elt (u_char *) a-elts a-size * a-nelts;a-nelts;return elt;
}/src/core/ngx_core.h
// ...
typedef struct ngx_pool_s ngx_pool_t;
// ...1.2、ngx_array组件的相关源码
/src/core/ngx_array.h /** Copyright (C) Igor Sysoev* Copyright (C) Nginx, Inc.*/#ifndef _NGX_ARRAY_H_INCLUDED_
#define _NGX_ARRAY_H_INCLUDED_#include ngx_config.h
#include ngx_core.htypedef struct {void *elts;ngx_uint_t nelts;size_t size;ngx_uint_t nalloc;ngx_pool_t *pool;
} ngx_array_t;ngx_array_t *ngx_array_create(ngx_pool_t *p, ngx_uint_t n, size_t size);
void ngx_array_destroy(ngx_array_t *a);
void *ngx_array_push(ngx_array_t *a);
void *ngx_array_push_n(ngx_array_t *a, ngx_uint_t n);static ngx_inline ngx_int_t
ngx_array_init(ngx_array_t *array, ngx_pool_t *pool, ngx_uint_t n, size_t size)
{/** set array-nelts before array-elts, otherwise MSVC thinks* that array-nelts may be used without having been initialized*/array-nelts 0;array-size size;array-nalloc n;array-pool pool;array-elts ngx_palloc(pool, n * size);if (array-elts NULL) {return NGX_ERROR;}return NGX_OK;
}#endif /* _NGX_ARRAY_H_INCLUDED_ */1.3、ngx_array的数据结构
typedef struct {void *elts;ngx_uint_t nelts;size_t size;ngx_uint_t nalloc;ngx_pool_t *pool;
} ngx_array_t;elts指向内存数据的指针。 nelts指示已使用了多少个元素。 size数组元素的大小。 nalloc分配的元素数量。 pool内存池。
array在内存里的布局
1.4、ngx_cycle简介和相关源码
Nginx的每个进程内部都有一个自己的ngx_cycle。
/src/core/ngx_cycle.h #ifndef _NGX_CYCLE_H_INCLUDED_
#define _NGX_CYCLE_H_INCLUDED_#include ngx_config.h
#include ngx_core.h#ifndef NGX_CYCLE_POOL_SIZE
#define NGX_CYCLE_POOL_SIZE NGX_DEFAULT_POOL_SIZE
#endif#define NGX_DEBUG_POINTS_STOP 1
#define NGX_DEBUG_POINTS_ABORT 2typedef struct ngx_shm_zone_s ngx_shm_zone_t;typedef ngx_int_t (*ngx_shm_zone_init_pt) (ngx_shm_zone_t *zone, void *data);struct ngx_shm_zone_s {void *data;ngx_shm_t shm;ngx_shm_zone_init_pt init;void *tag;ngx_uint_t noreuse; /* unsigned noreuse:1; */
};struct ngx_cycle_s {// ...
};typedef struct {// ...
} ngx_core_conf_t;#define ngx_is_init_cycle(cycle) (cycle-conf_ctx NULL)ngx_cycle_t *ngx_init_cycle(ngx_cycle_t *old_cycle);
ngx_int_t ngx_create_pidfile(ngx_str_t *name, ngx_log_t *log);
void ngx_delete_pidfile(ngx_cycle_t *cycle);
ngx_int_t ngx_signal_process(ngx_cycle_t *cycle, char *sig);
void ngx_reopen_files(ngx_cycle_t *cycle, ngx_uid_t user);
char **ngx_set_environment(ngx_cycle_t *cycle, ngx_uint_t *last);
ngx_pid_t ngx_exec_new_binary(ngx_cycle_t *cycle, char *const *argv);
ngx_cpuset_t *ngx_get_cpu_affinity(ngx_uint_t n);
ngx_shm_zone_t *ngx_shared_memory_add(ngx_conf_t *cf, ngx_str_t *name,size_t size, void *tag);
void ngx_set_shutdown_timer(ngx_cycle_t *cycle);extern volatile ngx_cycle_t *ngx_cycle;
extern ngx_array_t ngx_old_cycles;
extern ngx_module_t ngx_core_module;
extern ngx_uint_t ngx_test_config;
extern ngx_uint_t ngx_dump_config;
extern ngx_uint_t ngx_quiet_mode;#endif /* _NGX_CYCLE_H_INCLUDED_ */1.5、ngx_list相关源码
/src/core/ngx_list.h #ifndef _NGX_LIST_H_INCLUDED_
#define _NGX_LIST_H_INCLUDED_#include ngx_config.h
#include ngx_core.htypedef struct ngx_list_part_s ngx_list_part_t;struct ngx_list_part_s {void *elts;ngx_uint_t nelts;ngx_list_part_t *next;
};typedef struct {ngx_list_part_t *last;ngx_list_part_t part;size_t size;ngx_uint_t nalloc;ngx_pool_t *pool;
} ngx_list_t;ngx_list_t *ngx_list_create(ngx_pool_t *pool, ngx_uint_t n, size_t size);static ngx_inline ngx_int_t
ngx_list_init(ngx_list_t *list, ngx_pool_t *pool, ngx_uint_t n, size_t size)
{list-part.elts ngx_palloc(pool, n * size);if (list-part.elts NULL) {return NGX_ERROR;}list-part.nelts 0;list-part.next NULL;list-last list-part;list-size size;list-nalloc n;list-pool pool;return NGX_OK;
}/*** the iteration through the list:** part list.part;* data part-elts;** for (i 0 ;; i) {** if (i part-nelts) {* if (part-next NULL) {* break;* }** part part-next;* data part-elts;* i 0;* }** ... data[i] ...** }*/void *ngx_list_push(ngx_list_t *list);#endif /* _NGX_LIST_H_INCLUDED_ */1.6、ngx_list 的数据结构
typedef struct ngx_list_part_s ngx_list_part_t;struct ngx_list_part_s {void *elts;ngx_uint_t nelts;ngx_list_part_t *next;
};typedef struct {ngx_list_part_t *last;ngx_list_part_t part;size_t size;ngx_uint_t nalloc;ngx_pool_t *pool;
} ngx_list_t;elts指向内存数据的指针。 nelts指示已使用了多少个元素。 size数组元素的大小。 nalloc分配的元素数量。 pool内存池。
list 在内存里的布局
二、Nginx 组件的使用
Nginx的内存池分成大小块小块是要么不释放要么全部释放。ngx_create_pool(size_t size, ngx_log_t *log)里的size就是用来区分大小块的大于size的就是大块否则就是小块。
2.1、makefile的编写
CXX gcc
CXXFLAGS -g -Wall -WextraNGX_ROOT /home/fly/workspace/nginx-1.13.7TARGETS ngx_code
TARGETS_C_FILE $(TARGETS).cCLEANUP rm -f $(TARGETS) *.oall: $(TARGETS)clean:$(CLEANUP)CORE_INCS -I. \-I$(NGX_ROOT)/src/core \-I$(NGX_ROOT)/src/event \-I$(NGX_ROOT)/src/event/modules \-I$(NGX_ROOT)/src/os/unix \-I$(NGX_ROOT)/objs \-I$(NGX_ROOT)/../pcre-8.41 \-I$(NGX_ROOT)/../openssl-1.1.0g/include/ \NGX_PALLOC $(NGX_ROOT)/objs/src/core/ngx_palloc.o
NGX_STRING $(NGX_ROOT)/objs/src/core/ngx_string.o
NGX_ALLOC $(NGX_ROOT)/objs/src/os/unix/ngx_alloc.o
NGX_ARRAY $(NGX_ROOT)/objs/src/core/ngx_array.o
NGX_HASH $(NGX_ROOT)/objs/src/core/ngx_hash.o
NGX_LIST $(NGX_ROOT)/objs/src/core/ngx_list.o
NGX_QUEUE $(NGX_ROOT)/objs/src/core/ngx_queue.o$(TARGETS): $(TARGETS_C_FILE)$(CXX) $(CXXFLAGS) $(CORE_INCS) $(NGX_PALLOC) $(NGX_STRING)$(NGX_ALLOC) $(NGX_ARRAY) $(NGX_LIST) $(NGX_QUEUE) $(NGX_HASH) $^ -o $注意nginx的源码路径以及所需库的路径要写正确的。
2.2、ngx_pallocngx_array的使用
#include stdio.h#include ngx_config.h
#include ngx_conf_file.h
#include nginx.h
#include ngx_core.h
#include ngx_string.h
#include ngx_palloc.h
#include ngx_array.h
//#include ngx_hash.htypedef struct {int id;int level;
}ngx_fly_t;// 打印内存池的数据信息
void print_pool(ngx_pool_t *pool)
{while (pool){printf(avail pool memory size: %ld\n\n,pool-d.end - pool-d.last);poolpool-d.next;}
}volatile ngx_cycle_t *ngx_cycle;#define unused(x) (x)(x)
void ngx_log_error_core(ngx_uint_t level, ngx_log_t *log, ngx_err_t err,const char *fmt, ...)
{unused(level);unused(log);unused(err);unused(fmt);
}int main()
{ngx_str_t str ngx_string(Hello World!);printf(string length: %ld\n, str.len);printf(string: %s\n, str.data);// 创建内存池ngx_pool_t *pool;pool ngx_create_pool(1024, NULL);print_pool(pool);// 创建数组/** nalloc 32* size sizeof(ngx_fly_t)* pool pool*/ngx_array_t *arr ngx_array_create(pool, 32, sizeof(ngx_fly_t));print_pool(pool);ngx_fly_t *t1 ngx_array_push(arr); // 拿出内存t1-id 101; //赋值t1-level 1; //赋值print_pool(pool);ngx_fly_t *t2 ngx_array_push(arr); // 拿出内存t2-id 102; //赋值t2-level 3; //赋值print_pool(pool);return 0;
}使用makefile来编译执行结果
$ ./ngx_codestring length: 12
string: Hello World!
avail pool memory size: 944avail pool memory size: 648avail pool memory size: 648avail pool memory size: 648可以看到
代码中分配的内存池是1024分配之后只有944可以用有80字节被使用了。这80字节其实是被内存池的头占用了ngx_pool_t。分配完一个32的数组后内存池还剩余的内存为648也就是32*8256被分配给了数据。数组内存分配好之后使用数组元素已经不会再去申请内存池的内存。如果数组元素用完了还调用ngx_array_push会怎么样从ngx_array.c的源码中可以发现它会动态扩容数组重新分配2*size。
2.3、ngx_pallocngx_list的使用
#include stdio.h#include ngx_config.h
#include ngx_conf_file.h
#include nginx.h
#include ngx_core.h
#include ngx_string.h
#include ngx_palloc.h
#include ngx_array.h
//#include ngx_hash.htypedef struct {int id;int level;
}ngx_fly_t;// 打印内存池的数据信息
void print_pool(ngx_pool_t *pool)
{while (pool){printf(avail pool memory size: %ld\n\n,pool-d.end - pool-d.last);poolpool-d.next;}
}volatile ngx_cycle_t *ngx_cycle;#define unused(x) (x)(x)
void ngx_log_error_core(ngx_uint_t level, ngx_log_t *log, ngx_err_t err,const char *fmt, ...)
{unused(level);unused(log);unused(err);unused(fmt);
}int main()
{ngx_str_t str ngx_string(Hello World!);printf(string length: %ld\n, str.len);printf(string: %s\n, str.data);// 创建内存池ngx_pool_t *pool;pool ngx_create_pool(1024, NULL);print_pool(pool);ngx_list_t *listngx_list_create(pool, 32, sizeof(ngx_fly_t));print_pool(pool);ngx_fly_t *t3 ngx_list_push(list); // 拿出内存t3-id 103; //赋值t3-level 3; //赋值print_pool(pool);ngx_fly_t *t4 ngx_list_push(list); // 拿出内存t4-id 104; //赋值t4-level 4; //赋值print_pool(pool);return 0;
}使用makefile来编译执行结果
$ ./ngx_codestring length: 12
string: Hello World!
avail pool memory size: 944avail pool memory size: 632avail pool memory size: 632avail pool memory size: 632可以发现ngx_list相比ngx_array少了648 − 632 16字节从源码的ngx_list_create()函数可以发现是因为多了一个ngx_list_t的头数据。
总结
这里对ngx_string、ngx_array、ngx_list做了简单介绍和提供使用示例其他的nginx基础组件的使用比如dequeue、hash、log等等也是类似的。
