zenilib: zenilib/jni/external/sdl/src/thread/windows/SDL_syssem.c Source File

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SDL_syssem.c
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1 /*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "SDL_config.h"
22
23 #if SDL_THREAD_WINDOWS
24
25 /* Semaphore functions using the Win32 API */
26
27 #include "../../core/windows/SDL_windows.h"
28
29 #include "SDL_thread.h"
30
31 struct SDL_semaphore
32 {
33 HANDLE id;
34 LONG count;
35 };
36
37
38 /* Create a semaphore */
39 SDL_sem *
40 SDL_CreateSemaphore(Uint32 initial_value)
41 {
42 SDL_sem *sem;
43
44 /* Allocate sem memory */
45 sem = (SDL_sem *) SDL_malloc(sizeof(*sem));
46 if (sem) {
47 /* Create the semaphore, with max value 32K */
48 sem->id = CreateSemaphore(NULL, initial_value, 32 * 1024, NULL);
49 sem->count = initial_value;
50 if (!sem->id) {
51 SDL_SetError("Couldn't create semaphore");
52 SDL_free(sem);
53 sem = NULL;
54 }
55 } else {
56 SDL_OutOfMemory();
57 }
58 return (sem);
59 }
60
61 /* Free the semaphore */
62 void
63 SDL_DestroySemaphore(SDL_sem * sem)
64 {
65 if (sem) {
66 if (sem->id) {
67 CloseHandle(sem->id);
68 sem->id = 0;
69 }
70 SDL_free(sem);
71 }
72 }
73
74 int
75 SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
76 {
77 int retval;
78 DWORD dwMilliseconds;
79
80 if (!sem) {
81 return SDL_SetError("Passed a NULL sem");
82 }
83
84 if (timeout == SDL_MUTEX_MAXWAIT) {
85 dwMilliseconds = INFINITE;
86 } else {
87 dwMilliseconds = (DWORD) timeout;
88 }
89 switch (WaitForSingleObject(sem->id, dwMilliseconds)) {
90 case WAIT_OBJECT_0:
91 InterlockedDecrement(&sem->count);
92 retval = 0;
93 break;
94 case WAIT_TIMEOUT:
95 retval = SDL_MUTEX_TIMEDOUT;
96 break;
97 default:
98 retval = SDL_SetError("WaitForSingleObject() failed");
99 break;
100 }
101 return retval;
102 }
103
104 int
105 SDL_SemTryWait(SDL_sem * sem)
106 {
107 return SDL_SemWaitTimeout(sem, 0);
108 }
109
110 int
111 SDL_SemWait(SDL_sem * sem)
112 {
113 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
114 }
115
116 /* Returns the current count of the semaphore */
117 Uint32
118 SDL_SemValue(SDL_sem * sem)
119 {
120 if (!sem) {
121 SDL_SetError("Passed a NULL sem");
122 return 0;
123 }
124 return (Uint32)sem->count;
125 }
126
127 int
128 SDL_SemPost(SDL_sem * sem)
129 {
130 if (!sem) {
131 return SDL_SetError("Passed a NULL sem");
132 }
133 /* Increase the counter in the first place, because
134 * after a successful release the semaphore may
135 * immediately get destroyed by another thread which
136 * is waiting for this semaphore.
137 */
138 InterlockedIncrement(&sem->count);
139 if (ReleaseSemaphore(sem->id, 1, NULL) == FALSE) {
140 InterlockedDecrement(&sem->count); /* restore */
141 return SDL_SetError("ReleaseSemaphore() failed");
142 }
143 return 0;
144 }
145
146 #endif /* SDL_THREAD_WINDOWS */
147
148 /* vi: set ts=4 sw=4 expandtab: */
SDL_CreateSemaphore
DECLSPEC SDL_sem *SDLCALL SDL_CreateSemaphore(Uint32 initial_value)
Definition: SDL_syssem.c:85
SDL_MUTEX_MAXWAIT
#define SDL_MUTEX_MAXWAIT
Definition: SDL_mutex.h:49
SDL_SemTryWait
DECLSPEC int SDLCALL SDL_SemTryWait(SDL_sem *sem)
Definition: SDL_syssem.c:130
SDL_sem
struct SDL_semaphore SDL_sem
Definition: SDL_mutex.h:107
NULL
#define NULL
Definition: ftobjs.h:61
SDL_SemWaitTimeout
DECLSPEC int SDLCALL SDL_SemWaitTimeout(SDL_sem *sem, Uint32 ms)
Definition: SDL_syssem.c:150
SDL_SemWait
DECLSPEC int SDLCALL SDL_SemWait(SDL_sem *sem)
Definition: SDL_syssem.c:180
SDL_free
DECLSPEC void SDLCALL SDL_free(void *mem)
id
GLuint id
Definition: gl2ext.h:1142
SDL_config.h
Uint32
uint32_t Uint32
An unsigned 32-bit integer type.
Definition: SDL_stdinc.h:145
HANDLE
typedef HANDLE(WINAPI *PFNWGLCREATEBUFFERREGIONARBPROC)(HDC hDC
SDL_SemValue
DECLSPEC Uint32 SDLCALL SDL_SemValue(SDL_sem *sem)
Definition: SDL_syssem.c:186
count
GLint GLsizei count
Definition: gl2ext.h:1011
SDL_SetError
DECLSPEC int SDLCALL SDL_SetError(const char *fmt,...)
Definition: SDL_error.c:53
SDL_malloc
DECLSPEC void *SDLCALL SDL_malloc(size_t size)
FALSE
#define FALSE
Definition: ftobjs.h:57
timeout
GLbitfield GLuint64 timeout
Definition: glew.h:5938
SDL_DestroySemaphore
DECLSPEC void SDLCALL SDL_DestroySemaphore(SDL_sem *sem)
Definition: SDL_syssem.c:111
SDL_OutOfMemory
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
DWORD
typedef DWORD(WINAPI *XInputGetState_t)(DWORD dwUserIndex
SDL_MUTEX_TIMEDOUT
#define SDL_MUTEX_TIMEDOUT
Definition: SDL_mutex.h:44
SDL_SemPost
DECLSPEC int SDLCALL SDL_SemPost(SDL_sem *sem)
Definition: SDL_syssem.c:200