Mercurial > sdl-ios-xcode

annotate src/atomic/SDL_spinlock.c @ 5097:dceec93471e7

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Improvements based on feedback from Anthony Williams
author Sam Lantinga <slouken@libsdl.org>
date Tue, 25 Jan 2011 17:40:06 -0800
parents 2164a79b5ca9
children b938ad843e52
rev   line source
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
1 /*
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
2 SDL - Simple DirectMedia Layer
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
3 Copyright (C) 1997-2010 Sam Lantinga
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
4
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
5 This library is free software; you can redistribute it and/or
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
6 modify it under the terms of the GNU Lesser General Public
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
7 License as published by the Free Software Foundation; either
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
8 version 2.1 of the License, or (at your option) any later version.
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
9
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
10 This library is distributed in the hope that it will be useful,
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
13 Lesser General Public License for more details.
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
14
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
15 You should have received a copy of the GNU Lesser General Public
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
16 License along with this library; if not, write to the Free Software
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
18
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
19 Sam Lantinga
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
20 slouken@libsdl.org
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
21 */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
22 #include "SDL_stdinc.h"
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
23
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
24 #include "SDL_atomic.h"
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
25 #include "SDL_timer.h"
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
26
5073
1e94e68525d5 Fixed bug #1097
Sam Lantinga <slouken@libsdl.org>
parents: 5071
diff changeset
27 /* Don't do the check for Visual Studio 2005, it's safe here */
5093
2164a79b5ca9 Only include windows.h on Windows. :)
Sam Lantinga <slouken@libsdl.org>
parents: 5092
diff changeset
28 #ifdef __WIN32__
5092
327f181542f1 Include windows.h in a single point in the source, so we can be consistent about the definition of UNICODE and have core utility functions for Windows that all modules can share.
Sam Lantinga <slouken@libsdl.org>
parents: 5088
diff changeset
29 #include "../core/windows/SDL_windows.h"
5093
2164a79b5ca9 Only include windows.h on Windows. :)
Sam Lantinga <slouken@libsdl.org>
parents: 5092
diff changeset
30 #endif
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
31
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
32 /* This function is where all the magic happens... */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
33 SDL_bool
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
34 SDL_AtomicTryLock(SDL_SpinLock *lock)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
35 {
5028
fffb33ae85e8 Whoops, good catch from Greg Jandl
Sam Lantinga <slouken@libsdl.org>
parents: 5015
diff changeset
36 #if defined(_MSC_VER)
5015
1bf9e38431ec Use compiler intrinsics on Windows
Sam Lantinga <slouken@libsdl.org>
parents: 5004
diff changeset
37 SDL_COMPILE_TIME_ASSERT(locksize, sizeof(*lock) == sizeof(long));
5092
327f181542f1 Include windows.h in a single point in the source, so we can be consistent about the definition of UNICODE and have core utility functions for Windows that all modules can share.
Sam Lantinga <slouken@libsdl.org>
parents: 5088
diff changeset
38 return (InterlockedExchange((long*)lock, 1) == 0);
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
39
5097
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
40 #elif __MACOSX__
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
41 return OSAtomicCompareAndSwap32Barrier(0, 1, lock);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
42
5097
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
43 #elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
44 return (__sync_lock_test_and_set(lock, 1) == 0);
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
45
5097
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
46 #elif __GNUC__ && __arm__ && __ARM_ARCH_5__
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
47 int result;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
48 __asm__ __volatile__ (
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
49 "swp %0, %1, [%2]\n"
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
50 : "=&r,&r" (result) : "r,0" (1), "r,r" (lock) : "memory");
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
51 return (result == 0);
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
52
5097
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
53 #elif __GNUC__ && __arm__
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
54 int result;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
55 __asm__ __volatile__ (
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
56 "ldrex %0, [%2]\nteq %0, #0\nstrexeq %0, %1, [%2]"
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
57 : "=&r" (result) : "r" (1), "r" (lock) : "cc", "memory");
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
58 return (result == 0);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
59
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
60 #else
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
61 /* Need CPU instructions for spinlock here! */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
62 __need_spinlock_implementation__
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
63 #endif
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
64 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
65
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
66 void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
67 SDL_AtomicLock(SDL_SpinLock *lock)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
68 {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
69 /* FIXME: Should we have an eventual timeout? */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
70 while (!SDL_AtomicTryLock(lock)) {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
71 SDL_Delay(0);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
72 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
73 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
74
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
75 void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
76 SDL_AtomicUnlock(SDL_SpinLock *lock)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
77 {
5097
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
78 #if defined(_MSC_VER)
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
79 _ReadWriteBarrier();
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
80 *lock = 0;
5097
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
81
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
82 #elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
83 __sync_lock_release(lock);
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
84
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
85 #else
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
86 *lock = 0;
dceec93471e7 Improvements based on feedback from Anthony Williams
Sam Lantinga <slouken@libsdl.org>
parents: 5093
diff changeset
87 #endif
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
88 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
89
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
90 /* vi: set ts=4 sw=4 expandtab: */