1 /*
2 Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
3
4 This software is provided 'as-is', without any express or implied
5 warranty. In no event will the authors be held liable for any damages
6 arising from the use of this software.
7
8 Permission is granted to anyone to use this software for any purpose,
9 including commercial applications, and to alter it and redistribute it
10 freely.
11 */
12
13 /* Simple test of the SDL semaphore code */
14
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <signal.h>
18
19 #include "SDL.h"
20
21 #define NUM_THREADS 10
22
23 static SDL_sem *sem;
24 int alive = 1;
25
26 int SDLCALL
ThreadFunc(void * data)27 ThreadFunc(void *data)
28 {
29 int threadnum = (int) (uintptr_t) data;
30 while (alive) {
31 SDL_SemWait(sem);
32 SDL_Log("Thread number %d has got the semaphore (value = %d)!\n",
33 threadnum, SDL_SemValue(sem));
34 SDL_Delay(200);
35 SDL_SemPost(sem);
36 SDL_Log("Thread number %d has released the semaphore (value = %d)!\n",
37 threadnum, SDL_SemValue(sem));
38 SDL_Delay(1); /* For the scheduler */
39 }
40 SDL_Log("Thread number %d exiting.\n", threadnum);
41 return 0;
42 }
43
44 static void
killed(int sig)45 killed(int sig)
46 {
47 alive = 0;
48 }
49
50 static void
TestWaitTimeout(void)51 TestWaitTimeout(void)
52 {
53 Uint32 start_ticks;
54 Uint32 end_ticks;
55 Uint32 duration;
56 int retval;
57
58 sem = SDL_CreateSemaphore(0);
59 SDL_Log("Waiting 2 seconds on semaphore\n");
60
61 start_ticks = SDL_GetTicks();
62 retval = SDL_SemWaitTimeout(sem, 2000);
63 end_ticks = SDL_GetTicks();
64
65 duration = end_ticks - start_ticks;
66
67 /* Accept a little offset in the effective wait */
68 if (duration > 1900 && duration < 2050)
69 SDL_Log("Wait done.\n");
70 else
71 SDL_Log("Wait took %d milliseconds\n", duration);
72
73 /* Check to make sure the return value indicates timed out */
74 if (retval != SDL_MUTEX_TIMEDOUT)
75 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_SemWaitTimeout returned: %d; expected: %d\n", retval, SDL_MUTEX_TIMEDOUT);
76 }
77
78 int
main(int argc,char ** argv)79 main(int argc, char **argv)
80 {
81 SDL_Thread *threads[NUM_THREADS];
82 uintptr_t i;
83 int init_sem;
84
85 /* Enable standard application logging */
86 SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
87
88 if (argc < 2) {
89 SDL_Log("Usage: %s init_value\n", argv[0]);
90 return (1);
91 }
92
93 /* Load the SDL library */
94 if (SDL_Init(0) < 0) {
95 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
96 return (1);
97 }
98 signal(SIGTERM, killed);
99 signal(SIGINT, killed);
100
101 init_sem = atoi(argv[1]);
102 sem = SDL_CreateSemaphore(init_sem);
103
104 SDL_Log("Running %d threads, semaphore value = %d\n", NUM_THREADS,
105 init_sem);
106 /* Create all the threads */
107 for (i = 0; i < NUM_THREADS; ++i) {
108 char name[64];
109 SDL_snprintf(name, sizeof (name), "Thread%u", (unsigned int) i);
110 threads[i] = SDL_CreateThread(ThreadFunc, name, (void *) i);
111 }
112
113 /* Wait 10 seconds */
114 SDL_Delay(10 * 1000);
115
116 /* Wait for all threads to finish */
117 SDL_Log("Waiting for threads to finish\n");
118 alive = 0;
119 for (i = 0; i < NUM_THREADS; ++i) {
120 SDL_WaitThread(threads[i], NULL);
121 }
122 SDL_Log("Finished waiting for threads\n");
123
124 SDL_DestroySemaphore(sem);
125
126 TestWaitTimeout();
127
128 SDL_Quit();
129 return (0);
130 }
131