nginx/src/core/ngx_slab.h
Maxim Dounin 91ecc8f43c 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().
2011-11-23 13:55:38 +00:00

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C

/*
* Copyright (C) Igor Sysoev
*/
#ifndef _NGX_SLAB_H_INCLUDED_
#define _NGX_SLAB_H_INCLUDED_
#include <ngx_config.h>
#include <ngx_core.h>
typedef struct ngx_slab_page_s ngx_slab_page_t;
struct ngx_slab_page_s {
uintptr_t slab;
ngx_slab_page_t *next;
uintptr_t prev;
};
typedef struct {
ngx_shmtx_sh_t lock;
size_t min_size;
size_t min_shift;
ngx_slab_page_t *pages;
ngx_slab_page_t free;
u_char *start;
u_char *end;
ngx_shmtx_t mutex;
u_char *log_ctx;
u_char zero;
void *data;
void *addr;
} ngx_slab_pool_t;
void ngx_slab_init(ngx_slab_pool_t *pool);
void *ngx_slab_alloc(ngx_slab_pool_t *pool, size_t size);
void *ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size);
void ngx_slab_free(ngx_slab_pool_t *pool, void *p);
void ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p);
#endif /* _NGX_SLAB_H_INCLUDED_ */