diff options
Diffstat (limited to 'Utilities/cmlibuv/src/unix/atomic-ops.h')
| -rw-r--r-- | Utilities/cmlibuv/src/unix/atomic-ops.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/unix/atomic-ops.h b/Utilities/cmlibuv/src/unix/atomic-ops.h new file mode 100644 index 0000000000..2b58162153 --- /dev/null +++ b/Utilities/cmlibuv/src/unix/atomic-ops.h @@ -0,0 +1,70 @@ +/* Copyright (c) 2013, Ben Noordhuis <info@bnoordhuis.nl> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef UV_ATOMIC_OPS_H_ +#define UV_ATOMIC_OPS_H_ + +#include "internal.h" /* UV_UNUSED */ + +#if defined(__SUNPRO_C) || defined(__SUNPRO_CC) +#include <atomic.h> +#endif + +UV_UNUSED(static int cmpxchgi(int* ptr, int oldval, int newval)); +UV_UNUSED(static void cpu_relax(void)); + +/* Prefer hand-rolled assembly over the gcc builtins because the latter also + * issue full memory barriers. + */ +UV_UNUSED(static int cmpxchgi(int* ptr, int oldval, int newval)) { +#if defined(__i386__) || defined(__x86_64__) + int out; + __asm__ __volatile__ ("lock; cmpxchg %2, %1;" + : "=a" (out), "+m" (*(volatile int*) ptr) + : "r" (newval), "0" (oldval) + : "memory"); + return out; +#elif defined(_AIX) && defined(__ibmxl__) + /* FIXME: This is not actually atomic but XLClang 16.1 for AIX + does not provide __sync_val_compare_and_swap or an equivalent. + Its documentation suggests using C++11 atomics but this is C. */ + __compare_and_swap((volatile int*)ptr, &oldval, newval); + return oldval; +#elif defined(__MVS__) + /* Use hand-rolled assembly because codegen from builtin __plo_CSST results in + * a runtime bug. + */ + __asm(" cs %0,%2,%1 \n " : "+r"(oldval), "+m"(*ptr) : "r"(newval) :); + return oldval; +#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC) + return atomic_cas_uint((uint_t *)ptr, (uint_t)oldval, (uint_t)newval); +#else + return __sync_val_compare_and_swap(ptr, oldval, newval); +#endif +} + +UV_UNUSED(static void cpu_relax(void)) { +#if defined(__i386__) || defined(__x86_64__) + __asm__ __volatile__ ("rep; nop" ::: "memory"); /* a.k.a. PAUSE */ +#elif (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__) + __asm__ __volatile__ ("yield" ::: "memory"); +#elif (defined(__ppc__) || defined(__ppc64__)) && defined(__APPLE__) + __asm volatile ("" : : : "memory"); +#elif !defined(__APPLE__) && (defined(__powerpc64__) || defined(__ppc64__) || defined(__PPC64__)) + __asm__ __volatile__ ("or 1,1,1; or 2,2,2" ::: "memory"); +#endif +} + +#endif /* UV_ATOMIC_OPS_H_ */ |