Merge of r4339, r4340, r4341: Cache fixes: *) Obsolete code removed. The ngx_http_cache() and ngx_http_no_cache_set_slot() functions were replaced in 0.8.46 and no longer used since then. *) Handling of cache files with long headers. There are two possible situations which can lead to this: response was cached with bigger proxy_buffer_size value (and nginx was restared since then, i.e. shared memory zone content was lost), or due to the race in the cache update code (see [1]) we've end up with fcn->body_start from a different response stored in shared memory zone. *) Only complain on long locked entries. There have been multiple reports of cases where a real locked entry was removed, resulting in a segmentation fault later in a worker which locked the entry. It looks like default inactive timeout isn't enough in real life. For now just ignore such locked entries, and move them to the top of the inactive queue to allow processing of other entries. [1] http://mailman.nginx.org/pipermail/nginx-devel/2011-September/001287.html

/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_SHMTX_H_INCLUDED_
#define _NGX_SHMTX_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
#if (NGX_HAVE_ATOMIC_OPS)
    ngx_atomic_t  *lock;
#if (NGX_HAVE_POSIX_SEM)
    ngx_uint_t     semaphore;
    sem_t          sem;
#endif
#else
    ngx_fd_t       fd;
    u_char        *name;
#endif
    ngx_uint_t     spin;
} ngx_shmtx_t;


ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name);
void ngx_shmtx_destory(ngx_shmtx_t *mtx);
ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx);
void ngx_shmtx_lock(ngx_shmtx_t *mtx);
void ngx_shmtx_unlock(ngx_shmtx_t *mtx);


#endif /* _NGX_SHMTX_H_INCLUDED_ */