1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2020 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_internal.h"
22 
23 #if SDL_THREAD_PSP
24 
25 /* Semaphore functions for the PSP. */
26 
27 #include <stdio.h>
28 #include <stdlib.h>
29 
30 #include "SDL_error.h"
31 #include "SDL_thread.h"
32 
33 #include <pspthreadman.h>
34 #include <pspkerror.h>
35 
36 struct SDL_semaphore {
37     SceUID  semid;
38 };
39 
40 
41 /* Create a semaphore */
SDL_CreateSemaphore(Uint32 initial_value)42 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
43 {
44     SDL_sem *sem;
45 
46     sem = (SDL_sem *) malloc(sizeof(*sem));
47     if (sem != NULL) {
48         /* TODO: Figure out the limit on the maximum value. */
49         sem->semid = sceKernelCreateSema("SDL sema", 0, initial_value, 255, NULL);
50         if (sem->semid < 0) {
51             SDL_SetError("Couldn't create semaphore");
52             free(sem);
53             sem = NULL;
54         }
55     } else {
56         SDL_OutOfMemory();
57     }
58 
59     return sem;
60 }
61 
62 /* Free the semaphore */
SDL_DestroySemaphore(SDL_sem * sem)63 void SDL_DestroySemaphore(SDL_sem *sem)
64 {
65     if (sem != NULL) {
66         if (sem->semid > 0) {
67             sceKernelDeleteSema(sem->semid);
68             sem->semid = 0;
69         }
70 
71         free(sem);
72     }
73 }
74 
75 /* TODO: This routine is a bit overloaded.
76  * If the timeout is 0 then just poll the semaphore; if it's SDL_MUTEX_MAXWAIT, pass
77  * NULL to sceKernelWaitSema() so that it waits indefinitely; and if the timeout
78  * is specified, convert it to microseconds. */
SDL_SemWaitTimeout(SDL_sem * sem,Uint32 timeout)79 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
80 {
81     Uint32 *pTimeout;
82     int res;
83 
84     if (sem == NULL) {
85         SDL_SetError("Passed a NULL sem");
86         return 0;
87     }
88 
89     if (timeout == 0) {
90         res = sceKernelPollSema(sem->semid, 1);
91         if (res < 0) {
92             return SDL_MUTEX_TIMEDOUT;
93         }
94         return 0;
95     }
96 
97     if (timeout == SDL_MUTEX_MAXWAIT) {
98         pTimeout = NULL;
99     } else {
100         timeout *= 1000;  /* Convert to microseconds. */
101         pTimeout = &timeout;
102     }
103 
104     res = sceKernelWaitSema(sem->semid, 1, pTimeout);
105        switch (res) {
106                case SCE_KERNEL_ERROR_OK:
107                        return 0;
108                case SCE_KERNEL_ERROR_WAIT_TIMEOUT:
109                        return SDL_MUTEX_TIMEDOUT;
110                default:
111                        return SDL_SetError("sceKernelWaitSema() failed");
112     }
113 }
114 
SDL_SemTryWait(SDL_sem * sem)115 int SDL_SemTryWait(SDL_sem *sem)
116 {
117     return SDL_SemWaitTimeout(sem, 0);
118 }
119 
SDL_SemWait(SDL_sem * sem)120 int SDL_SemWait(SDL_sem *sem)
121 {
122     return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
123 }
124 
125 /* Returns the current count of the semaphore */
SDL_SemValue(SDL_sem * sem)126 Uint32 SDL_SemValue(SDL_sem *sem)
127 {
128     SceKernelSemaInfo info;
129 
130     if (sem == NULL) {
131         SDL_SetError("Passed a NULL sem");
132         return 0;
133     }
134 
135     if (sceKernelReferSemaStatus(sem->semid, &info) >= 0) {
136         return info.currentCount;
137     }
138 
139     return 0;
140 }
141 
SDL_SemPost(SDL_sem * sem)142 int SDL_SemPost(SDL_sem *sem)
143 {
144     int res;
145 
146     if (sem == NULL) {
147         return SDL_SetError("Passed a NULL sem");
148     }
149 
150     res = sceKernelSignalSema(sem->semid, 1);
151     if (res < 0) {
152         return SDL_SetError("sceKernelSignalSema() failed");
153     }
154 
155     return 0;
156 }
157 
158 #endif /* SDL_THREAD_PSP */
159 
160 /* vim: ts=4 sw=4
161  */
162