Mercurial > hg > nginx
view src/os/unix/ngx_atomic.h @ 7142:b9d919b53593 stable-1.12
Stream: relaxed next upstream condition (ticket #1317).
When switching to a next upstream, some buffers could be stuck in the middle
of the filter chain. A condition existed that raised an error when this
happened. As it turned out, this condition prevented switching to a next
upstream if ssl preread was used with the TCP protocol (see the ticket).
In fact, the condition does not make sense for TCP, since after successful
connection to an upstream switching to another upstream never happens. As for
UDP, the issue with stuck buffers is unlikely to happen, but is still possible.
Specifically, if a filter delays sending data to upstream.
The condition can be relaxed to only check the "buffered" bitmask of the
upstream connection. The new condition is simpler and fixes the ticket issue
as well. Additionally, the upstream_out chain is now reset for UDP prior to
connecting to a new upstream to prevent repeating the client data twice.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 11 Sep 2017 15:32:31 +0300 |
parents | 2cd019520210 |
children | 09d15a2dbc6b |
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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> #if (NGX_HAVE_LIBATOMIC) #define AO_REQUIRE_CAS #include <atomic_ops.h> #define NGX_HAVE_ATOMIC_OPS 1 typedef long ngx_atomic_int_t; typedef AO_t ngx_atomic_uint_t; typedef volatile ngx_atomic_uint_t ngx_atomic_t; #if (NGX_PTR_SIZE == 8) #define NGX_ATOMIC_T_LEN (sizeof("-9223372036854775808") - 1) #else #define NGX_ATOMIC_T_LEN (sizeof("-2147483648") - 1) #endif #define ngx_atomic_cmp_set(lock, old, new) \ AO_compare_and_swap(lock, old, new) #define ngx_atomic_fetch_add(value, add) \ AO_fetch_and_add(value, add) #define ngx_memory_barrier() AO_nop() #define ngx_cpu_pause() #elif (NGX_DARWIN_ATOMIC) /* * use Darwin 8 atomic(3) and barrier(3) operations * optimized at run-time for UP and SMP */ #include <libkern/OSAtomic.h> /* "bool" conflicts with perl's CORE/handy.h */ #if 0 #undef bool #endif #define NGX_HAVE_ATOMIC_OPS 1 #if (NGX_PTR_SIZE == 8) typedef int64_t ngx_atomic_int_t; typedef uint64_t ngx_atomic_uint_t; #define NGX_ATOMIC_T_LEN (sizeof("-9223372036854775808") - 1) #define ngx_atomic_cmp_set(lock, old, new) \ OSAtomicCompareAndSwap64Barrier(old, new, (int64_t *) lock) #define ngx_atomic_fetch_add(value, add) \ (OSAtomicAdd64(add, (int64_t *) value) - add) #else typedef int32_t ngx_atomic_int_t; typedef uint32_t ngx_atomic_uint_t; #define NGX_ATOMIC_T_LEN (sizeof("-2147483648") - 1) #define ngx_atomic_cmp_set(lock, old, new) \ OSAtomicCompareAndSwap32Barrier(old, new, (int32_t *) lock) #define ngx_atomic_fetch_add(value, add) \ (OSAtomicAdd32(add, (int32_t *) value) - add) #endif #define ngx_memory_barrier() OSMemoryBarrier() #define ngx_cpu_pause() typedef volatile ngx_atomic_uint_t ngx_atomic_t; #elif (NGX_HAVE_GCC_ATOMIC) /* GCC 4.1 builtin atomic operations */ #define NGX_HAVE_ATOMIC_OPS 1 typedef long ngx_atomic_int_t; typedef unsigned long ngx_atomic_uint_t; #if (NGX_PTR_SIZE == 8) #define NGX_ATOMIC_T_LEN (sizeof("-9223372036854775808") - 1) #else #define NGX_ATOMIC_T_LEN (sizeof("-2147483648") - 1) #endif typedef volatile ngx_atomic_uint_t ngx_atomic_t; #define ngx_atomic_cmp_set(lock, old, set) \ __sync_bool_compare_and_swap(lock, old, set) #define ngx_atomic_fetch_add(value, add) \ __sync_fetch_and_add(value, add) #define ngx_memory_barrier() __sync_synchronize() #if ( __i386__ || __i386 || __amd64__ || __amd64 ) #define ngx_cpu_pause() __asm__ ("pause") #else #define ngx_cpu_pause() #endif #elif ( __i386__ || __i386 ) 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 ( __SUNPRO_C ) #define NGX_HAVE_ATOMIC_OPS 1 ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old, ngx_atomic_uint_t set); ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add); /* * Sun Studio 12 exits with segmentation fault on '__asm ("pause")', * so ngx_cpu_pause is declared in src/os/unix/ngx_sunpro_x86.il */ void ngx_cpu_pause(void); /* the code in src/os/unix/ngx_sunpro_x86.il */ #define ngx_memory_barrier() __asm (".volatile"); __asm (".nonvolatile") #else /* ( __GNUC__ || __INTEL_COMPILER ) */ #define NGX_HAVE_ATOMIC_OPS 1 #include "ngx_gcc_atomic_x86.h" #endif #elif ( __amd64__ || __amd64 ) typedef int64_t ngx_atomic_int_t; typedef uint64_t ngx_atomic_uint_t; typedef volatile ngx_atomic_uint_t ngx_atomic_t; #define NGX_ATOMIC_T_LEN (sizeof("-9223372036854775808") - 1) #if ( __SUNPRO_C ) #define NGX_HAVE_ATOMIC_OPS 1 ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old, ngx_atomic_uint_t set); ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add); /* * Sun Studio 12 exits with segmentation fault on '__asm ("pause")', * so ngx_cpu_pause is declared in src/os/unix/ngx_sunpro_amd64.il */ void ngx_cpu_pause(void); /* the code in src/os/unix/ngx_sunpro_amd64.il */ #define ngx_memory_barrier() __asm (".volatile"); __asm (".nonvolatile") #else /* ( __GNUC__ || __INTEL_COMPILER ) */ #define NGX_HAVE_ATOMIC_OPS 1 #include "ngx_gcc_atomic_amd64.h" #endif #elif ( __sparc__ || __sparc || __sparcv9 ) #if (NGX_PTR_SIZE == 8) typedef int64_t ngx_atomic_int_t; typedef uint64_t ngx_atomic_uint_t; #define NGX_ATOMIC_T_LEN (sizeof("-9223372036854775808") - 1) #else typedef int32_t ngx_atomic_int_t; typedef uint32_t ngx_atomic_uint_t; #define NGX_ATOMIC_T_LEN (sizeof("-2147483648") - 1) #endif typedef volatile ngx_atomic_uint_t ngx_atomic_t; #if ( __SUNPRO_C ) #define NGX_HAVE_ATOMIC_OPS 1 #include "ngx_sunpro_atomic_sparc64.h" #else /* ( __GNUC__ || __INTEL_COMPILER ) */ #define NGX_HAVE_ATOMIC_OPS 1 #include "ngx_gcc_atomic_sparc64.h" #endif #elif ( __powerpc__ || __POWERPC__ ) #define NGX_HAVE_ATOMIC_OPS 1 #if (NGX_PTR_SIZE == 8) typedef int64_t ngx_atomic_int_t; typedef uint64_t ngx_atomic_uint_t; #define NGX_ATOMIC_T_LEN (sizeof("-9223372036854775808") - 1) #else typedef int32_t ngx_atomic_int_t; typedef uint32_t ngx_atomic_uint_t; #define NGX_ATOMIC_T_LEN (sizeof("-2147483648") - 1) #endif typedef volatile ngx_atomic_uint_t ngx_atomic_t; #include "ngx_gcc_atomic_ppc.h" #endif #if !(NGX_HAVE_ATOMIC_OPS) #define NGX_HAVE_ATOMIC_OPS 0 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) static ngx_inline ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old, ngx_atomic_uint_t set) { if (*lock == old) { *lock = set; return 1; } return 0; } static ngx_inline ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add) { ngx_atomic_int_t old; old = *value; *value += add; return old; } #define ngx_memory_barrier() #define ngx_cpu_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_ */