text: /*
    Copyright (C) 1997-2011 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.
  */
  
  /* 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;
  }
  
  static void
  TestWaitTimeout(void)
  {
      Uint32 start_ticks;
      Uint32 end_ticks;
      Uint32 duration;
  
      sem = SDL_CreateSemaphore(0);
      printf("Waiting 2 seconds on semaphore\n");
  
      start_ticks = SDL_GetTicks();
      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)
          printf("Wait done.\n");
      else
          fprintf(stderr, "Wait took %d milliseconds\n", duration);
  }
  
  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);
  
      TestWaitTimeout();
  
      SDL_Quit();
      return (0);
  }
  