Stream: avoid potential infinite loop at preread phase. Previously the preread phase code ignored NGX_AGAIN value returned from c->recv() and relied only on c->read->ready. But this flag is not reliable and should only be checked for optimization purposes. For example, when using SSL, c->read->ready may be set when no input is available. This can lead to calling preread handler infinitely in a loop.

/*
 * Copyright (C) Ruslan Ermilov
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_RWLOCK_H_INCLUDED_
#define _NGX_RWLOCK_H_INCLUDED_


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


void ngx_rwlock_wlock(ngx_atomic_t *lock);
void ngx_rwlock_rlock(ngx_atomic_t *lock);
void ngx_rwlock_unlock(ngx_atomic_t *lock);
void ngx_rwlock_downgrade(ngx_atomic_t *lock);


#endif /* _NGX_RWLOCK_H_INCLUDED_ */