view test/testsem.c @ 615:7ec821f3cbd0

Date: Thu, 17 Apr 2003 23:27:34 -0400 From: Darrell Walisser Subject: Yet another OS X cursor bug The synopsis: 1. Call SDL_ShowCursor(0); 2. Call SDL_SetVideoMode(); 3. Call SDL_GetEvent(); 3. Call SDL_ShowCursor(1); The result: Sometimes the cursor doesn't come back! Ack! Oddly enough, it does come back when mousing over the dock or clicking in the menu bar. But that's besides the point. The reason why this is happening is a flaw in the handling of activation/deactivation events. The short explanation is that the HideCursor() and ShowCursor() calls must be balanced, but if the cursor was initially hidden, HideCursor() was called again on the activate event - so now the next ShowCursor() fails (as does the next, and the next, for some reason). So, here's the patch. All it does is keep track of the HideCursor()/ShowCursor() calls so that they will always be balanced.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 20 Apr 2003 05:41:16 +0000
parents 74212992fb08
children be9c9c8f6d53
line wrap: on
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/* 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 ThreadFunc(void *data)
{
	while ( alive ) {
		SDL_SemWait(sem);
		fprintf(stderr, "Thread number %d has got the semaphore (value = %d)!\n", (int)data, SDL_SemValue(sem));
		SDL_Delay(200);
		SDL_SemPost(sem);
		fprintf(stderr, "Thread number %d has released the semaphore (value = %d)!\n", (int)data, SDL_SemValue(sem));
		SDL_Delay(1); /* For the scheduler */
	}
	printf("Thread number %d exiting.\n", (int)data);
	return 0;
}

static void killed(int sig)
{
	alive = 0;
}

int main(int argc, char **argv)
{
	SDL_Thread *threads[NUM_THREADS];
	int i, init_sem;

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

	/* Load the SDL library */
	if ( SDL_Init(0) < 0 ) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
		exit(1);
	}
	atexit(SDL_Quit);
	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);
	return(0);
}