view test/testlock.c @ 1157:baf35853ad54

Date: Mon, 10 Oct 2005 13:09:32 +0300 From: Tommi Kyntola <tommi.kyntola@ray.fi> To: sdl@libsdl.org Subject: [SDL] [RFC] get_ticks broken on linux It uses gettimeofday to calculate the timedifference. Gettimeofday returns current time which is seldom monotonous. This breaks SDL timer subsystem. (time callbacks and all that get borked when the time difference ms is suddenly ~ 2^32) I posted a message about this earlier but got no response. Some thoughts on this matter would be appreciated. (Or even an explanation for the lack of interest.) A patch below would use the posix timers that have been around since posix 93 and do provide a good source of monotonous time on linux boxes (and on few others too). The following patch is also availabe at: http://www.hut.fi/u/tkyntola/SDL-1.2.9-clockfix.patch It's against 1.2.9, but I can easily rediffit against the cvs branch is needed. cheers, Tommi Kyntola tommi.kyntola@ray.fi
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 11 Oct 2005 18:16:12 +0000
parents be9c9c8f6d53
children 14717b52abc0
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/* Test the thread and mutex locking functions 
   Also exercises the system's signal/thread interaction
*/

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

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

static SDL_mutex *mutex = NULL;
static Uint32 mainthread;
static SDL_Thread *threads[6];

/*
 * 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)
{
	printf("Process %u:  exiting\n", SDL_ThreadID());
}
	
void terminate(int sig)
{
	printf("Process %u:  raising SIGTERM\n", SDL_ThreadID());
	raise(SIGTERM);
}
void closemutex(int sig)
{
	Uint32 id = SDL_ThreadID();
	int i;
	printf("Process %u:  Cleaning up...\n", id == mainthread ? 0 : id);
	for ( i=0; i<6; ++i )
		SDL_KillThread(threads[i]);
	SDL_DestroyMutex(mutex);
	exit(sig);
}
int Run(void *data)
{
	if ( SDL_ThreadID() == mainthread )
		signal(SIGTERM, closemutex);
	while ( 1 ) {
		printf("Process %u ready to work\n", SDL_ThreadID());
		if ( SDL_mutexP(mutex) < 0 ) {
			fprintf(stderr, "Couldn't lock mutex: %s", SDL_GetError());
			exit(1);
		}
		printf("Process %u, working!\n", SDL_ThreadID());
		SDL_Delay(1*1000);
		printf("Process %u, done!\n", SDL_ThreadID());
		if ( SDL_mutexV(mutex) < 0 ) {
			fprintf(stderr, "Couldn't unlock mutex: %s", SDL_GetError());
			exit(1);
		}
		/* If this sleep isn't done, then threads may starve */
		SDL_Delay(10);
	}
	return(0);
}

int main(int argc, char *argv[])
{
	int i;
	int maxproc = 6;

	/* Load the SDL library */
	if ( SDL_Init(0) < 0 ) {
		fprintf(stderr, "%s\n", SDL_GetError());
		exit(1);
	}
	atexit(SDL_Quit_Wrapper);

	if ( (mutex=SDL_CreateMutex()) == NULL ) {
		fprintf(stderr, "Couldn't create mutex: %s\n", SDL_GetError());
		exit(1);
	}

	mainthread = SDL_ThreadID();
	printf("Main thread: %u\n", mainthread);
	atexit(printid);
	for ( i=0; i<maxproc; ++i ) {
		if ( (threads[i]=SDL_CreateThread(Run, NULL)) == NULL )
			fprintf(stderr, "Couldn't create thread!\n");
	}
	signal(SIGINT, terminate);
	Run(NULL);

	return(0);	/* Never reached */
}