testsem.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include "SDL.h"

Include dependency graph for testsem.c:

Go to the source code of this file.

Macros
#define	NUM_THREADS   10

Functions
int	ThreadFunc (void *data)
static void	killed (int sig)
static void	TestWaitTimeout (void)
int	main (int argc, char **argv)

Variables
static SDL_sem *	sem
int	alive = 1

Macro Definition Documentation

#define NUM_THREADS   10

Definition at line 21 of file testsem.c.

Referenced by main().

Function Documentation

static void killed ( int  sig )

static

Definition at line 45 of file testsem.c.

References alive.

Referenced by main().

{
    alive = 0;
}

int main	(	int	argc,
		char **	argv
	)

Definition at line 79 of file testsem.c.

References alive, i, killed(), NULL, NUM_THREADS, SDL_CreateSemaphore, SDL_CreateThread, SDL_Delay, SDL_DestroySemaphore, SDL_GetError, SDL_Init, SDL_Log, SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, SDL_LogError, SDL_LogSetPriority, SDL_Quit, SDL_snprintf, SDL_WaitThread, sem, TestWaitTimeout(), ThreadFunc(), and threads.

{
    SDL_Thread *threads[NUM_THREADS];
    uintptr_t i;
    int init_sem;

    /* Enable standard application logging */
    SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);

    if (argc < 2) {
        SDL_Log("Usage: %s init_value\n", argv[0]);
        return (1);
    }

    /* Load the SDL library */
    if (SDL_Init(0) < 0) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "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);

    SDL_Log("Running %d threads, semaphore value = %d\n", NUM_THREADS,
           init_sem);
    /* Create all the threads */
    for (i = 0; i < NUM_THREADS; ++i) {
        char name[64];
        SDL_snprintf(name, sizeof (name), "Thread%u", (unsigned int) i);
        threads[i] = SDL_CreateThread(ThreadFunc, name, (void *) i);
    }

    /* Wait 10 seconds */
    SDL_Delay(10 * 1000);

    /* Wait for all threads to finish */
    SDL_Log("Waiting for threads to finish\n");
    alive = 0;
    for (i = 0; i < NUM_THREADS; ++i) {
        SDL_WaitThread(threads[i], NULL);
    }
    SDL_Log("Finished waiting for threads\n");

    SDL_DestroySemaphore(sem);

    TestWaitTimeout();

    SDL_Quit();
    return (0);
}

static void TestWaitTimeout ( void  )

static

Definition at line 51 of file testsem.c.

References retval, SDL_CreateSemaphore, SDL_GetTicks(), SDL_Log, SDL_LOG_CATEGORY_APPLICATION, SDL_LogError, SDL_MUTEX_TIMEDOUT, SDL_SemWaitTimeout, and sem.

Referenced by main().

{
    Uint32 start_ticks;
    Uint32 end_ticks;
    Uint32 duration;
    int retval;

    sem = SDL_CreateSemaphore(0);
    SDL_Log("Waiting 2 seconds on semaphore\n");

    start_ticks = SDL_GetTicks();
    retval = SDL_SemWaitTimeout(sem, 2000);
    end_ticks = SDL_GetTicks();

    duration = end_ticks - start_ticks;

    /* Accept a little offset in the effective wait */
    if (duration > 1900 && duration < 2050)
        SDL_Log("Wait done.\n");
    else
        SDL_Log("Wait took %d milliseconds\n", duration);

    /* Check to make sure the return value indicates timed out */
    if (retval != SDL_MUTEX_TIMEDOUT)
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_SemWaitTimeout returned: %d; expected: %d\n", retval, SDL_MUTEX_TIMEDOUT);
}

int ThreadFunc

(

void *

data

)

Definition at line 27 of file testsem.c.

References alive, SDL_Delay, SDL_Log, SDL_SemPost, SDL_SemValue, SDL_SemWait, and sem.

{
    int threadnum = (int) (uintptr_t) data;
    while (alive) {
        SDL_SemWait(sem);
        SDL_Log("Thread number %d has got the semaphore (value = %d)!\n",
                threadnum, SDL_SemValue(sem));
        SDL_Delay(200);
        SDL_SemPost(sem);
        SDL_Log("Thread number %d has released the semaphore (value = %d)!\n",
                threadnum, SDL_SemValue(sem));
        SDL_Delay(1);           /* For the scheduler */
    }
    SDL_Log("Thread number %d exiting.\n", threadnum);
    return 0;
}

Variable Documentation

int alive = 1

Definition at line 24 of file testsem.c.

Referenced by killed(), main(), and ThreadFunc().

SDL_sem* sem

static

Definition at line 23 of file testsem.c.

Referenced by main(), SDL_CreateSemaphore(), TestWaitTimeout(), and ThreadFunc().