view test/torturethread.c @ 3899:081aecdb0911 SDL-1.2

From: Gabriel Gambetta To: SDL Mailing List <sdl@libsdl.org> Date: Fri, 17 Nov 2006 00:39:29 -0200 Subject: [SDL] Alpha blending bug - fixed? It turns out mm5 never got the correct value. This failed : [...] "movd %1, %%mm5\n\t" : : "m" (amask), "m" (sf->Ashift) ); mm5 got 0xFF000018 instead of 0x00000018. However I did this : Uint32 ashift = sf->Ashift; [...] "movd %1, %%mm5\n\t" : : "m" (amask), "m" (ashift) ); and everything worked fine. The only thing I could find out was that ashift is 32-bit aligned but sf->Ashift isn't: printf("ashift %8X [%d]\n", &ashift, (int)(&ashift) % 4); printf("sf->Ashift %8X [%d]\n", &sf->Ashift, (int)(&sf->Ashift) % 4); ashift at BFF0E0C4 [0] sf->Ashift at 08AFB9CD [1] Could this be the problem? If it is, the fix is extremely trivial. Should I submit a patch? --Gabriel
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 21 Nov 2006 23:17:00 +0000
parents 290b5baf2fca
children 782fd950bd46 c121d94672cb
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line source


/* Simple test of the SDL threading code */

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>

#include "SDL.h"
#include "SDL_thread.h"

#define NUMTHREADS 10

static char volatile time_for_threads_to_die[NUMTHREADS];

/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void quit(int rc)
{
	SDL_Quit();
	exit(rc);
}

int SDLCALL SubThreadFunc(void *data) {
	while(! *(int volatile *)data) {
		; /*SDL_Delay(10);*/  /* do nothing */
	}
	return 0;
}

int SDLCALL ThreadFunc(void *data) {
	SDL_Thread *sub_threads[NUMTHREADS];
	int flags[NUMTHREADS];
	int i;
	int tid = (int)(uintptr_t)data;

	fprintf(stderr, "Creating Thread %d\n", tid);

	for(i = 0; i < NUMTHREADS; i++) {
		flags[i] = 0;
		sub_threads[i] = SDL_CreateThread(SubThreadFunc, &flags[i]);
	}

	printf("Thread '%d' waiting for signal\n", tid);
	while(time_for_threads_to_die[tid] != 1) {
		; /* do nothing */
	}

	printf("Thread '%d' sending signals to subthreads\n", tid);
	for(i = 0; i <  NUMTHREADS; i++) {
		flags[i] = 1;
		SDL_WaitThread(sub_threads[i], NULL);
	}

	printf("Thread '%d' exiting!\n", tid);

	return 0;
}

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

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

	signal(SIGSEGV, SIG_DFL);
	for(i = 0; i < NUMTHREADS; i++) {
		time_for_threads_to_die[i] = 0;
		threads[i] = SDL_CreateThread(ThreadFunc, (void *)(uintptr_t)i);
	
		if ( threads[i] == NULL ) {
			fprintf(stderr,
			"Couldn't create thread: %s\n", SDL_GetError());
			quit(1);
		}
	}

	for(i = 0; i < NUMTHREADS; i++) {
		time_for_threads_to_die[i] = 1;
	}

	for(i = 0; i < NUMTHREADS; i++) {
		SDL_WaitThread(threads[i], NULL);
	}
	SDL_Quit();
	return(0);
}