1 

     2 /* Simple test of the SDL semaphore code */

     3 

     4 #include <stdio.h>

     5 #include <stdlib.h>

     6 #include <signal.h>

     7 

     8 #include "SDL.h"

     9 #include "SDL_thread.h"

    10 

    11 #define NUM_THREADS 10

    12 

    13 static SDL_sem *sem;

    14 int alive = 1;

    15 

    16 int SDLCALL ThreadFunc(void *data)

    17 {

    18 	int threadnum = (int)(uintptr_t)data;

    19 	while ( alive ) {

    20 		SDL_SemWait(sem);

    21 		fprintf(stderr, "Thread number %d has got the semaphore (value = %d)!\n", threadnum, SDL_SemValue(sem));

    22 		SDL_Delay(200);

    23 		SDL_SemPost(sem);

    24 		fprintf(stderr, "Thread number %d has released the semaphore (value = %d)!\n", threadnum, SDL_SemValue(sem));

    25 		SDL_Delay(1); /* For the scheduler */

    26 	}

    27 	printf("Thread number %d exiting.\n", threadnum);

    28 	return 0;

    29 }

    30 

    31 static void killed(int sig)

    32 {

    33 	alive = 0;

    34 }

    35 

    36 int main(int argc, char **argv)

    37 {

    38 	SDL_Thread *threads[NUM_THREADS];

    39 	uintptr_t i;

    40 	int init_sem;

    41 

    42 	if(argc < 2) {

    43 		fprintf(stderr,"Usage: %s init_value\n", argv[0]);

    44 		return(1);

    45 	}

    46 

    47 	/* Load the SDL library */

    48 	if ( SDL_Init(0) < 0 ) {

    49 		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());

    50 		return(1);

    51 	}

    52 	signal(SIGTERM, killed);

    53 	signal(SIGINT, killed);

    54 	

    55 	init_sem = atoi(argv[1]);

    56 	sem = SDL_CreateSemaphore(init_sem);

    57 	

    58 	printf("Running %d threads, semaphore value = %d\n", NUM_THREADS, init_sem);

    59 	/* Create all the threads */

    60 	for( i = 0; i < NUM_THREADS; ++i ) {

    61 		threads[i] = SDL_CreateThread(ThreadFunc, (void*)i);

    62 	}

    63 

    64 	/* Wait 10 seconds */

    65 	SDL_Delay(10 * 1000);

    66 

    67 	/* Wait for all threads to finish */

    68 	printf("Waiting for threads to finish\n");

    69 	alive = 0;

    70 	for( i = 0; i < NUM_THREADS; ++i ) {

    71 		SDL_WaitThread(threads[i], NULL);

    72 	}

    73 	printf("Finished waiting for threads\n");

    74 

    75 	SDL_DestroySemaphore(sem);

    76 	SDL_Quit();

    77 	return(0);

    78 }