Fixed sendfile in threads (or with aio preload) and subrequests. If sendfile in threads is used, it is possible that multiple subrequests will trigger multiple ngx_linux_sendfile_thread() calls, as operations are only serialized in output chain based on r->aio, that is, on subrequest level. This resulted in "task #N already active" alerts, in particular, when running proxy_store.t with "aio threads; sendfile on;". Fix is to tolerate duplicate calls, with an additional safety check that the file is the same as previously used. The same problem also affects "aio on; sendfile on;" on FreeBSD (previously known as "aio sendfile;"), where aio->preload_handler() could be called multiple times due to similar reasons, resulting in "second aio post" alerts. Fix is the same as well. It is also believed that similar problems can arise if a filter calls the next body filter multiple times for some reason. These are mostly theoretical though.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_SHA1_H_INCLUDED_
#define _NGX_SHA1_H_INCLUDED_


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


#if (NGX_HAVE_OPENSSL_SHA1_H)
#include <openssl/sha.h>
#else
#include <sha.h>
#endif


typedef SHA_CTX  ngx_sha1_t;


#define ngx_sha1_init    SHA1_Init
#define ngx_sha1_update  SHA1_Update
#define ngx_sha1_final   SHA1_Final


#endif /* _NGX_SHA1_H_INCLUDED_ */