Mercurial > sdl-ios-xcode

annotate src/atomic/SDL_spinlock.c @ 5050:2add0d17180b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
SDL doesn't depend on GLU, and overwhelming feedback from the mailing list is that people don't want it included in SDL_opengl.h
author Sam Lantinga <slouken@libsdl.org>
date Wed, 19 Jan 2011 22:55:51 -0800
parents fffb33ae85e8
children fd125217f00c
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
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
27
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
28 /* 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
29 SDL_bool
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
30 SDL_AtomicTryLock(SDL_SpinLock *lock)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
31 {
5028
fffb33ae85e8 Whoops, good catch from Greg Jandl
Sam Lantinga <slouken@libsdl.org>
parents: 5015
diff changeset
32 #if defined(_MSC_VER)
5015
1bf9e38431ec Use compiler intrinsics on Windows
Sam Lantinga <slouken@libsdl.org>
parents: 5004
diff changeset
33 SDL_COMPILE_TIME_ASSERT(locksize, sizeof(*lock) == sizeof(long));
1bf9e38431ec Use compiler intrinsics on Windows
Sam Lantinga <slouken@libsdl.org>
parents: 5004
diff changeset
34 return (_InterlockedExchange((long*)lock, 1) == 0);
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
35
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
36 #elif defined(__MACOSX__)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
37 return OSAtomicCompareAndSwap32Barrier(0, 1, lock);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
38
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
39 #elif defined(HAVE_GCC_ATOMICS)
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
40 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
41
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
42 #elif defined(__GNUC__) && defined(__arm__) && defined(__ARM_ARCH_5__)
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
43 int result;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
44 __asm__ __volatile__ (
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
45 "swp %0, %1, [%2]\n"
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
46 : "=&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
47 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
48
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
49 #elif defined(__GNUC__) && defined(__arm__)
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
50 int result;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
51 __asm__ __volatile__ (
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
52 "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
53 : "=&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
54 return (result == 0);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
55
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
56 #else
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
57 /* Need CPU instructions for spinlock here! */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
58 __need_spinlock_implementation__
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
59 #endif
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
60 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
61
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
62 void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
63 SDL_AtomicLock(SDL_SpinLock *lock)
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 /* FIXME: Should we have an eventual timeout? */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
66 while (!SDL_AtomicTryLock(lock)) {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
67 SDL_Delay(0);
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 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
70
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
71 void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
72 SDL_AtomicUnlock(SDL_SpinLock *lock)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
73 {
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
74 /* Assuming atomic assignment operation and full memory barrier in lock */
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
75 *lock = 0;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
76 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
77
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
78 /* vi: set ts=4 sw=4 expandtab: */