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comparison src/thread/windows/SDL_syssem.c @ 5062:e8916fe9cfc8

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Fixed bug #925 Changed "win32" to "windows"
author Sam Lantinga <slouken@libsdl.org>
date Thu, 20 Jan 2011 18:04:05 -0800
parents src/thread/win32/SDL_syssem.c@883a2f2ff43f
children c2539ff054c8
comparison
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5061:9e9940eae455 5062:e8916fe9cfc8
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2010 Sam Lantinga
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with this library; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19 Sam Lantinga
20 slouken@libsdl.org
21 */
22 #include "SDL_config.h"
23
24 /* Semaphore functions using the Win32 API */
25
26 #define WIN32_LEAN_AND_MEAN
27 #include <windows.h>
28
29 #include "SDL_thread.h"
30 #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
31 #include "win_ce_semaphore.h"
32 #endif
33
34
35 struct SDL_semaphore
36 {
37 #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
38 SYNCHHANDLE id;
39 #else
40 HANDLE id;
41 #endif
42 LONG volatile count;
43 };
44
45
46 /* Create a semaphore */
47 SDL_sem *
48 SDL_CreateSemaphore(Uint32 initial_value)
49 {
50 SDL_sem *sem;
51
52 /* Allocate sem memory */
53 sem = (SDL_sem *) SDL_malloc(sizeof(*sem));
54 if (sem) {
55 /* Create the semaphore, with max value 32K */
56 #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
57 sem->id = CreateSemaphoreCE(NULL, initial_value, 32 * 1024, NULL);
58 #else
59 sem->id = CreateSemaphore(NULL, initial_value, 32 * 1024, NULL);
60 #endif
61 sem->count = initial_value;
62 if (!sem->id) {
63 SDL_SetError("Couldn't create semaphore");
64 SDL_free(sem);
65 sem = NULL;
66 }
67 } else {
68 SDL_OutOfMemory();
69 }
70 return (sem);
71 }
72
73 /* Free the semaphore */
74 void
75 SDL_DestroySemaphore(SDL_sem * sem)
76 {
77 if (sem) {
78 if (sem->id) {
79 #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
80 CloseSynchHandle(sem->id);
81 #else
82 CloseHandle(sem->id);
83 #endif
84 sem->id = 0;
85 }
86 SDL_free(sem);
87 }
88 }
89
90 int
91 SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
92 {
93 int retval;
94 DWORD dwMilliseconds;
95
96 if (!sem) {
97 SDL_SetError("Passed a NULL sem");
98 return -1;
99 }
100
101 if (timeout == SDL_MUTEX_MAXWAIT) {
102 dwMilliseconds = INFINITE;
103 } else {
104 dwMilliseconds = (DWORD) timeout;
105 }
106 #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
107 switch (WaitForSemaphoreCE(sem->id, dwMilliseconds)) {
108 #else
109 switch (WaitForSingleObject(sem->id, dwMilliseconds)) {
110 #endif
111 case WAIT_OBJECT_0:
112 InterlockedDecrement(&sem->count);
113 retval = 0;
114 break;
115 case WAIT_TIMEOUT:
116 retval = SDL_MUTEX_TIMEDOUT;
117 break;
118 default:
119 SDL_SetError("WaitForSingleObject() failed");
120 retval = -1;
121 break;
122 }
123 return retval;
124 }
125
126 int
127 SDL_SemTryWait(SDL_sem * sem)
128 {
129 return SDL_SemWaitTimeout(sem, 0);
130 }
131
132 int
133 SDL_SemWait(SDL_sem * sem)
134 {
135 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
136 }
137
138 /* Returns the current count of the semaphore */
139 Uint32
140 SDL_SemValue(SDL_sem * sem)
141 {
142 if (!sem) {
143 SDL_SetError("Passed a NULL sem");
144 return 0;
145 }
146 return (Uint32)sem->count;
147 }
148
149 int
150 SDL_SemPost(SDL_sem * sem)
151 {
152 if (!sem) {
153 SDL_SetError("Passed a NULL sem");
154 return -1;
155 }
156 /* Increase the counter in the first place, because
157 * after a successful release the semaphore may
158 * immediately get destroyed by another thread which
159 * is waiting for this semaphore.
160 */
161 InterlockedIncrement(&sem->count);
162 #if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
163 if (ReleaseSemaphoreCE(sem->id, 1, NULL) == FALSE) {
164 #else
165 if (ReleaseSemaphore(sem->id, 1, NULL) == FALSE) {
166 #endif
167 InterlockedDecrement(&sem->count); /* restore */
168 SDL_SetError("ReleaseSemaphore() failed");
169 return -1;
170 }
171 return 0;
172 }
173
174 /* vi: set ts=4 sw=4 expandtab: */