view src/core/ngx_palloc.h @ 4309:3f6040cd731e

Added shmtx interface to forcibly unlock mutexes. It is currently used from master process on abnormal worker termination to unlock accept mutex (unlocking of accept mutex was broken in 1.0.2). It is expected to be used in the future to unlock other mutexes as well. Shared mutex code was rewritten to make this possible in a safe way, i.e. with a check if lock was actually held by the exited process. We again use pid to lock mutex, and use separate atomic variable for a count of processes waiting in sem_wait().
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 23 Nov 2011 13:55:38 +0000
parents d788521e4b0e
children d620f497c50f
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 */


#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;


void *ngx_alloc(size_t size, ngx_log_t *log);
void *ngx_calloc(size_t size, ngx_log_t *log);

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_ */