Mercurial > hg > nginx-quic
view src/os/win32/ngx_atomic.h @ 6536:f7849bfb6d21
Improved EPOLLRDHUP handling.
When it's known that the kernel supports EPOLLRDHUP, there is no need in
additional recv() call to get EOF or error when the flag is absent in the
event generated by the kernel. A special runtime test is done at startup
to detect if EPOLLRDHUP is actually supported by the kernel because
epoll_ctl() silently ignores unknown flags.
With this knowledge it's now possible to drop the "ready" flag for partial
read. Previously, the "ready" flag was kept until the recv() returned EOF
or error. In particular, this change allows the lingering close heuristics
(which relies on the "ready" flag state) to actually work on Linux, and not
wait for more data in most cases.
The "available" flag is now used in the read event with the semantics similar
to the corresponding counter in kqueue.
| author | Valentin Bartenev <vbart@nginx.com> |
|---|---|
| date | Fri, 13 May 2016 17:19:23 +0300 |
| parents | 2cd019520210 |
| children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_ATOMIC_H_INCLUDED_ #define _NGX_ATOMIC_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #define NGX_HAVE_ATOMIC_OPS 1 typedef int32_t ngx_atomic_int_t; typedef uint32_t ngx_atomic_uint_t; typedef volatile ngx_atomic_uint_t ngx_atomic_t; #define NGX_ATOMIC_T_LEN (sizeof("-2147483648") - 1) #if defined( __WATCOMC__ ) || defined( __BORLANDC__ ) || defined(__GNUC__) \ || ( _MSC_VER >= 1300 ) /* the new SDK headers */ #define ngx_atomic_cmp_set(lock, old, set) \ ((ngx_atomic_uint_t) InterlockedCompareExchange((long *) lock, set, old) \ == old) #else /* the old MS VC6.0SP2 SDK headers */ #define ngx_atomic_cmp_set(lock, old, set) \ (InterlockedCompareExchange((void **) lock, (void *) set, (void *) old) \ == (void *) old) #endif #define ngx_atomic_fetch_add(p, add) InterlockedExchangeAdd((long *) p, add) #define ngx_memory_barrier() #if defined( __BORLANDC__ ) || ( __WATCOMC__ < 1230 ) /* * Borland C++ 5.5 (tasm32) and Open Watcom C prior to 1.3 * do not understand the "pause" instruction */ #define ngx_cpu_pause() #else #define ngx_cpu_pause() __asm { pause } #endif void ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin); #define ngx_trylock(lock) (*(lock) == 0 && ngx_atomic_cmp_set(lock, 0, 1)) #define ngx_unlock(lock) *(lock) = 0 #endif /* _NGX_ATOMIC_H_INCLUDED_ */