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 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 /* Mutex functions using the OS/2 API */
25
26 #define INCL_DOSERRORS
27 #define INCL_DOSSEMAPHORES
28 #include <os2.h>
29
30 #include "SDL_mutex.h"
31
32
33 struct SDL_mutex {
34 HMTX hmtxID;
35 };
36
37 /* Create a mutex */
SDL_CreateMutex(void)38 DECLSPEC SDL_mutex * SDLCALL SDL_CreateMutex(void)
39 {
40 SDL_mutex *mutex;
41 APIRET ulrc;
42
43 /* Allocate mutex memory */
44 mutex = (SDL_mutex *)SDL_malloc(sizeof(*mutex));
45 if (mutex)
46 {
47 /* Create the mutex, with initial value signaled */
48 ulrc = DosCreateMutexSem(NULL, // Create unnamed semaphore
49 &(mutex->hmtxID), // Pointer to handle
50 0L, // Flags: create it private (not shared)
51 FALSE); // Initial value: unowned
52 if (ulrc!=NO_ERROR)
53 {
54 SDL_SetError("Couldn't create mutex");
55 SDL_free(mutex);
56 mutex = NULL;
57 }
58 } else {
59 SDL_OutOfMemory();
60 }
61 return(mutex);
62 }
63
64 /* Free the mutex */
SDL_DestroyMutex(SDL_mutex * mutex)65 DECLSPEC void SDLCALL SDL_DestroyMutex(SDL_mutex *mutex)
66 {
67 if ( mutex )
68 {
69 if ( mutex->hmtxID )
70 {
71 DosCloseMutexSem(mutex->hmtxID);
72 mutex->hmtxID = 0;
73 }
74 SDL_free(mutex);
75 }
76 }
77
78 /* Lock the mutex */
SDL_mutexP(SDL_mutex * mutex)79 DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex *mutex)
80 {
81 if ( mutex == NULL )
82 {
83 SDL_SetError("Passed a NULL mutex");
84 return -1;
85 }
86 if ( DosRequestMutexSem(mutex->hmtxID, SEM_INDEFINITE_WAIT) != NO_ERROR )
87 {
88 SDL_SetError("Couldn't wait on mutex");
89 return -1;
90 }
91 return(0);
92 }
93
94 /* Unlock the mutex */
SDL_mutexV(SDL_mutex * mutex)95 DECLSPEC int SDLCALL SDL_mutexV(SDL_mutex *mutex)
96 {
97 if ( mutex == NULL )
98 {
99 SDL_SetError("Passed a NULL mutex");
100 return -1;
101 }
102 if ( DosReleaseMutexSem(mutex->hmtxID) != NO_ERROR )
103 {
104 SDL_SetError("Couldn't release mutex");
105 return -1;
106 }
107 return(0);
108 }
109