/*

  Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied

  warranty.  In no event will the authors be held liable for any damages

  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,

  including commercial applications, and to alter it and redistribute it

  freely.

*/

/* Test the thread and mutex locking functions

   Also exercises the system's signal/thread interaction

*/

#include <signal.h>

#include <stdio.h>

#include <stdlib.h> /* for atexit() */

#include "SDL.h"

static SDL_mutex *mutex = NULL;

static SDL_threadID mainthread;

static SDL_Thread *threads[6];

static volatile int doterminate = 0;

/*

 * SDL_Quit() shouldn't be used with atexit() directly because

 *  calling conventions may differ...

 */

static void

SDL_Quit_Wrapper(void)

{

    SDL_Quit();

}

void

printid(void)

{

    SDL_Log("Process %lu:  exiting\n", SDL_ThreadID());

}

void

terminate(int sig)

{

    signal(SIGINT, terminate);

    doterminate = 1;

}

void

closemutex(int sig)

{

    SDL_threadID id = SDL_ThreadID();

    int i;

    SDL_Log("Process %lu:  Cleaning up...\n", id == mainthread ? 0 : id);

    doterminate = 1;

    for (i = 0; i < 6; ++i)

        SDL_WaitThread(threads[i], NULL);

    SDL_DestroyMutex(mutex);

    exit(sig);

}

int SDLCALL

Run(void *data)

{

    if (SDL_ThreadID() == mainthread)

        signal(SIGTERM, closemutex);

    while (!doterminate) {

        SDL_Log("Process %lu ready to work\n", SDL_ThreadID());

        if (SDL_LockMutex(mutex) < 0) {

            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't lock mutex: %s", SDL_GetError());

            exit(1);

        }

        SDL_Log("Process %lu, working!\n", SDL_ThreadID());

        SDL_Delay(1 * 1000);

        SDL_Log("Process %lu, done!\n", SDL_ThreadID());

        if (SDL_UnlockMutex(mutex) < 0) {

            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't unlock mutex: %s", SDL_GetError());

            exit(1);

        }

        /* If this sleep isn't done, then threads may starve */

        SDL_Delay(10);

    }

    if (SDL_ThreadID() == mainthread && doterminate) {

        SDL_Log("Process %lu:  raising SIGTERM\n", SDL_ThreadID());

        raise(SIGTERM);

    }

    return (0);

}

int

main(int argc, char *argv[])

{

    int i;

    int maxproc = 6;

	/* Enable standard application logging */

    SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);

    /* Load the SDL library */

    if (SDL_Init(0) < 0) {

        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "%s\n", SDL_GetError());

        exit(1);

    }

    atexit(SDL_Quit_Wrapper);

    if ((mutex = SDL_CreateMutex()) == NULL) {

        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create mutex: %s\n", SDL_GetError());

        exit(1);

    }

    mainthread = SDL_ThreadID();

    SDL_Log("Main thread: %lu\n", mainthread);

    atexit(printid);

    for (i = 0; i < maxproc; ++i) {

        char name[64];

        SDL_snprintf(name, sizeof (name), "Worker%d", i);

        if ((threads[i] = SDL_CreateThread(Run, name, NULL)) == NULL)

            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create thread!\n");

    }

    signal(SIGINT, terminate);

    Run(NULL);

    return (0);                 /* Never reached */

}