Mercurial > sdl-ios-xcode
view test/testsem.c @ 3696:47d923feedb0
Fixed bug #935
Patrice Mandin
Hello,
I originally added pth support for threads in SDL 1.2 because on the Atari
platform we did not have any thread library.
I think pth support could be removed from SDL 1.3 for two reasons:
- Atari platform removed
- pth does not provides real (preemptive) threads, because it is user space,
and expect the application to call one of its function to give CPU to another
thread. So it is not exactly useful for applications, that expect threads to
run simultaneously.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 24 Jan 2010 20:47:20 +0000 |
parents | c121d94672cb |
children | d547877e355e |
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line source
/* 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); }