Mercurial > sdl-ios-xcode

annotate src/atomic/SDL_atomic.c @ 5072:2341ecc03388

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Whitespace change in a README.
author Ryan C. Gordon <icculus@icculus.org>
date Sat, 22 Jan 2011 03:57:27 -0500
parents 0c72ae7b7cb2
children dceec93471e7
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
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
26 /* Note that we undefine the atomic operations here, in case they are
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
27 defined as compiler intrinsics while building SDL but the library user
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
28 doesn't have that compiler. That way we always have a working set of
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
29 atomic operations built into the library.
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
30 */
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
31
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
32 /*
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
33 If any of the operations are not provided then we must emulate some
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
34 of them. That means we need a nice implementation of spin locks
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
35 that avoids the "one big lock" problem. We use a vector of spin
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
36 locks and pick which one to use based on the address of the operand
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
37 of the function.
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
38
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
39 To generate the index of the lock we first shift by 3 bits to get
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
40 rid on the zero bits that result from 32 and 64 bit allignment of
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
41 data. We then mask off all but 5 bits and use those 5 bits as an
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
42 index into the table.
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
43
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
44 Picking the lock this way insures that accesses to the same data at
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
45 the same time will go to the same lock. OTOH, accesses to different
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
46 data have only a 1/32 chance of hitting the same lock. That should
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
47 pretty much eliminate the chances of several atomic operations on
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
48 different data from waiting on the same "big lock". If it isn't
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
49 then the table of locks can be expanded to a new size so long as
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
50 the new size is a power of two.
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
51
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
52 Contributed by Bob Pendleton, bob@pendleton.com
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
53 */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
54
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
55 static SDL_SpinLock locks[32];
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
56
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
57 static __inline__ void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
58 enterLock(void *a)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
59 {
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
60 uintptr_t index = ((((uintptr_t)a) >> 3) & 0x1f);
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
61
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
62 SDL_AtomicLock(&locks[index]);
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
63 }
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 static __inline__ void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
66 leaveLock(void *a)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
67 {
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
68 uintptr_t index = ((((uintptr_t)a) >> 3) & 0x1f);
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
69
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
70 SDL_AtomicUnlock(&locks[index]);
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
71 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
72
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
73 #undef SDL_AtomicSet
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
74 int
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
75 SDL_AtomicSet(SDL_atomic_t *a, int value)
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 int oldvalue;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
78
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
79 enterLock(a);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
80 oldvalue = a->value;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
81 a->value = value;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
82 leaveLock(a);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
83
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
84 return oldvalue;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
85 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
86
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
87 #undef SDL_AtomicGet
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
88 int
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
89 SDL_AtomicGet(SDL_atomic_t *a)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
90 {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
91 /* Assuming integral reads on this platform, we're safe here since the
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
92 functions that set the variable have the necessary memory barriers.
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
93 */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
94 return a->value;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
95 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
96
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
97 #undef SDL_AtomicAdd
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
98 int
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
99 SDL_AtomicAdd(SDL_atomic_t *a, int value)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
100 {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
101 int oldvalue;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
102
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
103 enterLock(a);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
104 oldvalue = a->value;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
105 a->value += value;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
106 leaveLock(a);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
107
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
108 return oldvalue;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
109 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
110
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
111 #undef SDL_AtomicIncRef
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
112 void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
113 SDL_AtomicIncRef(SDL_atomic_t *a)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
114 {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
115 SDL_AtomicAdd(a, 1);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
116 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
117
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
118 #undef SDL_AtomicDecRef
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
119 SDL_bool
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
120 SDL_AtomicDecRef(SDL_atomic_t *a)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
121 {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
122 return SDL_AtomicAdd(a, -1) == 1;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
123 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
124
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
125 #undef SDL_AtomicCAS
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
126 SDL_bool
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
127 SDL_AtomicCAS(SDL_atomic_t *a, int oldval, int newval)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
128 {
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
129 SDL_bool retval = SDL_FALSE;
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
130
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
131 enterLock(a);
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
132 if (a->value == oldval) {
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
133 a->value = newval;
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
134 retval = SDL_TRUE;
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
135 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
136 leaveLock(a);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
137
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
138 return retval;
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
139 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
140
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
141 #undef SDL_AtomicSetPtr
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
142 void
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
143 SDL_AtomicSetPtr(void** a, void* value)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
144 {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
145 void *prevval;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
146 do {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
147 prevval = *a;
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
148 } while (!SDL_AtomicCASPtr(a, prevval, value));
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
149 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
150
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
151 #undef SDL_AtomicGetPtr
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
152 void*
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
153 SDL_AtomicGetPtr(void** a)
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
154 {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
155 /* Assuming integral reads on this platform, we're safe here since the
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
156 functions that set the pointer have the necessary memory barriers.
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
157 */
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
158 return *a;
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
159 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
160
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
161 #undef SDL_AtomicCASPtr
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
162 SDL_bool SDL_AtomicCASPtr(void **a, void *oldval, void *newval)
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
163 {
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
164 SDL_bool retval = SDL_FALSE;
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
165
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
166 enterLock(a);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
167 if (*a == oldval) {
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
168 *a = newval;
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
169 retval = SDL_TRUE;
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
170 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
171 leaveLock(a);
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
172
5004
0c72ae7b7cb2 Added native atomic operations for Windows, Mac OS X, and gcc compiler intrinsics.
Sam Lantinga <slouken@libsdl.org>
parents: 5003
diff changeset
173 return retval;
5003
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
174 }
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
175
3a95a2b93eb3 Updated the atomic API for better use cases
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
176 /* vi: set ts=4 sw=4 expandtab: */