1 /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22 #ifndef UV_WIN_ATOMICOPS_INL_H_
23 #define UV_WIN_ATOMICOPS_INL_H_
24
25 #include "uv.h"
26 #include "internal.h"
27
28
29 /* Atomic set operation on char */
30 #ifdef _MSC_VER /* MSVC */
31
32 /* _InterlockedOr8 is supported by MSVC on x32 and x64. It is slightly less
33 * efficient than InterlockedExchange, but InterlockedExchange8 does not exist,
34 * and interlocked operations on larger targets might require the target to be
35 * aligned. */
36 #pragma intrinsic(_InterlockedOr8)
37
uv__atomic_exchange_set(char volatile * target)38 static char INLINE uv__atomic_exchange_set(char volatile* target) {
39 return _InterlockedOr8(target, 1);
40 }
41
42 #else /* GCC, Clang in mingw mode */
43
uv__atomic_exchange_set(char volatile * target)44 static inline char uv__atomic_exchange_set(char volatile* target) {
45 #if defined(__i386__) || defined(__x86_64__)
46 /* Mingw-32 version, hopefully this works for 64-bit gcc as well. */
47 const char one = 1;
48 char old_value;
49 __asm__ __volatile__ ("lock xchgb %0, %1\n\t"
50 : "=r"(old_value), "=m"(*target)
51 : "0"(one), "m"(*target)
52 : "memory");
53 return old_value;
54 #else
55 return __sync_fetch_and_or(target, 1);
56 #endif
57 }
58
59 #endif
60
61 #endif /* UV_WIN_ATOMICOPS_INL_H_ */
62
