1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2012 Sam Lantinga
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 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 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19 Sam Lantinga
20 slouken@devolution.com
21 */
22
23 /*
24 SDL_syssem.cpp
25
26 Epoc version by Markus Mertama (w@iki.fi)
27 */
28
29 #ifdef SAVE_RCSID
30 static char rcsid =
31 "@(#) $Id: SDL_syssem.c,v 1.1.2.4 2000/06/22 15:24:48 hercules Exp $";
32 #endif
33
34 /* Semaphore functions using the Win32 API */
35
36 //#include <stdio.h>
37 //#include <stdlib.h>
38 #include <e32std.h>
39
40 #include "SDL_error.h"
41 #include "SDL_thread.h"
42
43
44 #define SDL_MUTEX_TIMEOUT -2
45
46 struct SDL_semaphore
47 {
48 TInt handle;
49 TInt count;
50 };
51
52
53 extern TInt CreateUnique(TInt (*aFunc)(const TDesC& aName, TAny*, TAny*), TAny*, TAny*);
54 #ifndef EKA2
55 extern TInt NewThread(const TDesC& aName, TAny* aPtr1, TAny* aPtr2);
56 #endif
57
NewSema(const TDesC & aName,TAny * aPtr1,TAny * aPtr2)58 TInt NewSema(const TDesC& aName, TAny* aPtr1, TAny* aPtr2)
59 {
60 TInt value = *((TInt*) aPtr2);
61 return ((RSemaphore*)aPtr1)->CreateGlobal(aName, value);
62 }
63
64 /* Create a semaphore */
SDL_CreateSemaphore(Uint32 initial_value)65 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
66 {
67 RSemaphore s;
68 TInt status = CreateUnique(NewSema, &s, &initial_value);
69 if(status != KErrNone)
70 {
71 SDL_SetError("Couldn't create semaphore");
72 }
73 SDL_semaphore* sem = new /*(ELeave)*/ SDL_semaphore;
74 sem->handle = s.Handle();
75 sem->count = initial_value;
76 return(sem);
77 }
78
79 /* Free the semaphore */
SDL_DestroySemaphore(SDL_sem * sem)80 void SDL_DestroySemaphore(SDL_sem *sem)
81 {
82 if ( sem )
83 {
84 RSemaphore sema;
85 sema.SetHandle(sem->handle);
86 while(--sem->count)
87 sema.Signal();
88 sema.Close();
89 delete sem;
90 sem = NULL;
91 }
92 }
93
94 #ifndef EKA2
95
96 struct TInfo
97 {
TInfoTInfo98 TInfo(TInt aTime, TInt aHandle) :
99 iTime(aTime), iHandle(aHandle), iVal(0) {}
100 TInt iTime;
101 TInt iHandle;
102 TInt iVal;
103 };
104
105
106
ThreadRun(TAny * aInfo)107 TBool ThreadRun(TAny* aInfo)
108 {
109 TInfo* info = STATIC_CAST(TInfo*, aInfo);
110 User::After(info->iTime);
111 RSemaphore sema;
112 sema.SetHandle(info->iHandle);
113 sema.Signal();
114 info->iVal = SDL_MUTEX_TIMEOUT;
115 return 0;
116 }
117
118 #endif
119
120
_WaitAll(SDL_sem * sem)121 void _WaitAll(SDL_sem *sem)
122 {
123 //since SemTryWait may changed the counter.
124 //this may not be atomic, but hopes it works.
125 RSemaphore sema;
126 sema.SetHandle(sem->handle);
127 sema.Wait();
128 while(sem->count < 0)
129 {
130 sema.Wait();
131 }
132 }
133
SDL_SemWaitTimeout(SDL_sem * sem,Uint32 timeout)134 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
135 {
136 if ( ! sem ) {
137 SDL_SetError("Passed a NULL sem");
138 return -1;
139 }
140
141 if ( timeout == SDL_MUTEX_MAXWAIT )
142 {
143 _WaitAll(sem);
144 return SDL_MUTEX_MAXWAIT;
145 }
146
147 #ifdef EKA2
148
149 RSemaphore sema;
150 sema.SetHandle(sem->handle);
151 if(KErrNone == sema.Wait(timeout))
152 return 0;
153 return -1;
154 #else
155 RThread thread;
156
157 TInfo* info = new (ELeave)TInfo(timeout, sem->handle);
158
159 TInt status = CreateUnique(NewThread, &thread, info);
160
161 if(status != KErrNone)
162 return status;
163
164 thread.Resume();
165
166 _WaitAll(sem);
167
168 if(thread.ExitType() == EExitPending)
169 {
170 thread.Kill(SDL_MUTEX_TIMEOUT);
171 }
172
173 thread.Close();
174
175 return info->iVal;
176 #endif
177 }
178
SDL_SemTryWait(SDL_sem * sem)179 int SDL_SemTryWait(SDL_sem *sem)
180 {
181 if(sem->count > 0)
182 {
183 sem->count--;
184 }
185 return SDL_MUTEX_TIMEOUT;
186 }
187
SDL_SemWait(SDL_sem * sem)188 int SDL_SemWait(SDL_sem *sem)
189 {
190 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
191 }
192
193 /* Returns the current count of the semaphore */
SDL_SemValue(SDL_sem * sem)194 Uint32 SDL_SemValue(SDL_sem *sem)
195 {
196 if ( ! sem ) {
197 SDL_SetError("Passed a NULL sem");
198 return 0;
199 }
200 return sem->count;
201 }
202
SDL_SemPost(SDL_sem * sem)203 int SDL_SemPost(SDL_sem *sem)
204 {
205 if ( ! sem ) {
206 SDL_SetError("Passed a NULL sem");
207 return -1;
208 }
209 sem->count++;
210 RSemaphore sema;
211 sema.SetHandle(sem->handle);
212 sema.Signal();
213 return 0;
214 }
215