This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
/
testsem.c
86 lines (71 loc) · 1.94 KB
/
testsem.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
/* Simple test of the SDL semaphore code */
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include "SDL.h"
#include "SDL_thread.h"
#define NUM_THREADS 10
static SDL_sem *sem;
int alive = 1;
int SDLCALL
ThreadFunc (void *data)
{
int threadnum = (int) (uintptr_t) data;
while (alive) {
SDL_SemWait (sem);
fprintf (stderr,
"Thread number %d has got the semaphore (value = %d)!\n",
threadnum, SDL_SemValue (sem));
SDL_Delay (200);
SDL_SemPost (sem);
fprintf (stderr,
"Thread number %d has released the semaphore (value = %d)!\n",
threadnum, SDL_SemValue (sem));
SDL_Delay (1); /* For the scheduler */
}
printf ("Thread number %d exiting.\n", threadnum);
return 0;
}
static void
killed (int sig)
{
alive = 0;
}
int
main (int argc, char **argv)
{
SDL_Thread *threads[NUM_THREADS];
uintptr_t i;
int init_sem;
if (argc < 2) {
fprintf (stderr, "Usage: %s init_value\n", argv[0]);
return (1);
}
/* Load the SDL library */
if (SDL_Init (0) < 0) {
fprintf (stderr, "Couldn't initialize SDL: %s\n", SDL_GetError ());
return (1);
}
signal (SIGTERM, killed);
signal (SIGINT, killed);
init_sem = atoi (argv[1]);
sem = SDL_CreateSemaphore (init_sem);
printf ("Running %d threads, semaphore value = %d\n", NUM_THREADS,
init_sem);
/* Create all the threads */
for (i = 0; i < NUM_THREADS; ++i) {
threads[i] = SDL_CreateThread (ThreadFunc, (void *) i);
}
/* Wait 10 seconds */
SDL_Delay (10 * 1000);
/* Wait for all threads to finish */
printf ("Waiting for threads to finish\n");
alive = 0;
for (i = 0; i < NUM_THREADS; ++i) {
SDL_WaitThread (threads[i], NULL);
}
printf ("Finished waiting for threads\n");
SDL_DestroySemaphore (sem);
SDL_Quit ();
return (0);
}