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view src/core/ngx_queue.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 | 72db8932f782 |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #ifndef _NGX_QUEUE_H_INCLUDED_ #define _NGX_QUEUE_H_INCLUDED_ typedef struct ngx_queue_s ngx_queue_t; struct ngx_queue_s { ngx_queue_t *prev; ngx_queue_t *next; }; #define ngx_queue_init(q) \ (q)->prev = q; \ (q)->next = q #define ngx_queue_empty(h) \ (h == (h)->prev) #define ngx_queue_insert_head(h, x) \ (x)->next = (h)->next; \ (x)->next->prev = x; \ (x)->prev = h; \ (h)->next = x #define ngx_queue_insert_after ngx_queue_insert_head #define ngx_queue_insert_tail(h, x) \ (x)->prev = (h)->prev; \ (x)->prev->next = x; \ (x)->next = h; \ (h)->prev = x #define ngx_queue_head(h) \ (h)->next #define ngx_queue_last(h) \ (h)->prev #define ngx_queue_sentinel(h) \ (h) #define ngx_queue_next(q) \ (q)->next #define ngx_queue_prev(q) \ (q)->prev #if (NGX_DEBUG) #define ngx_queue_remove(x) \ (x)->next->prev = (x)->prev; \ (x)->prev->next = (x)->next; \ (x)->prev = NULL; \ (x)->next = NULL #else #define ngx_queue_remove(x) \ (x)->next->prev = (x)->prev; \ (x)->prev->next = (x)->next #endif #define ngx_queue_split(h, q, n) \ (n)->prev = (h)->prev; \ (n)->prev->next = n; \ (n)->next = q; \ (h)->prev = (q)->prev; \ (h)->prev->next = h; \ (q)->prev = n; #define ngx_queue_add(h, n) \ (h)->prev->next = (n)->next; \ (n)->next->prev = (h)->prev; \ (h)->prev = (n)->prev; \ (h)->prev->next = h; #define ngx_queue_data(q, type, link) \ (type *) ((u_char *) q - offsetof(type, link)) ngx_queue_t *ngx_queue_middle(ngx_queue_t *queue); void ngx_queue_sort(ngx_queue_t *queue, ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *)); #endif /* _NGX_QUEUE_H_INCLUDED_ */