Mercurial > hg > nginx
view src/os/unix/ngx_atomic.h @ 9236:d9a52ebb9b00
Mail: max_commands directive.
The directive specifies the maximum number of commands allowed during
authentication, after which the connection is closed. The default
limit is 1000, which is not expected to affect any well-behaving clients,
since authentication usually requires at most several commands, though
will effectively stop malicious clients from flooding the server with
with commands.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Sat, 30 Mar 2024 05:05:53 +0300 |
| parents | 09d15a2dbc6b |
| 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> #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_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 (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 ( __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_ */