Mercurial > hg > nginx-quic
view src/os/win32/ngx_atomic.h @ 8759:56dec0d4e5b1 quic
QUIC: avoid excessive buffer allocations in stream output.
Previously, when a few bytes were send to a QUIC stream by the application, a
4K buffer was allocated for these bytes. Then a STREAM frame was created and
that entire buffer was used as data for that frame. The frame with the buffer
were in use up until the frame was acked by client. Meanwhile, when more
bytes were send to the stream, more buffers were allocated and assigned as
data to newer STREAM frames. In this scenario most buffer memory is unused.
Now the unused part of the stream output buffer is available for further
stream output while earlier parts of the buffer are waiting to be acked.
This is achieved by splitting the output buffer.
| author | Roman Arutyunyan <arut@nginx.com> |
|---|---|
| date | Fri, 24 Dec 2021 18:13:51 +0300 |
| parents | 2cd019520210 |
| children |
line wrap: on
line source
/* * 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_ */