view src/thread/SDL_thread.c @ 1207:c9ec00d3e8bc

To: sdl@libsdl.org From: Christian Walther <cwalther@gmx.ch> Date: Wed, 21 Dec 2005 13:39:39 +0100 Subject: [SDL] Another mouse bug patch for Mac OS X Oh my, yet another change in the quartz mouse handling code! :) The attached patch fixes the following bug: Calling SDL_WarpMouse() while the cursor is invisible and grabbed should only update SDL's internal mouse location, not try to warp the system cursor (which is not at that location, but fixed in the middle of the window). Otherwise, the next mouse motion event is wrong. Please apply. Thanks Christian
author Ryan C. Gordon <icculus@icculus.org>
date Wed, 21 Dec 2005 18:02:36 +0000
parents 173c063d4f55
children c9b51268668f
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

/* System independent thread management routines for SDL */

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

#include "SDL_error.h"
#include "SDL_mutex.h"
#include "SDL_thread.h"
#include "SDL_thread_c.h"
#include "SDL_systhread.h"

#define ARRAY_CHUNKSIZE	32
/* The array of threads currently active in the application
   (except the main thread)
   The manipulation of an array here is safer than using a linked list.
*/
static int SDL_maxthreads = 0;
static int SDL_numthreads = 0;
static SDL_Thread **SDL_Threads = NULL;
static SDL_mutex *thread_lock = NULL;
int _creating_thread_lock = 0;

int SDL_ThreadsInit(void)
{
	int retval;

	retval = 0;
	/* Set the thread lock creation flag so that we can reuse an
	   existing lock on the system - since this mutex never gets
	   destroyed (see SDL_ThreadsQuit()), we want to reuse it.
	*/
	_creating_thread_lock = 1;
	thread_lock = SDL_CreateMutex();
	_creating_thread_lock = 0;
	if ( thread_lock == NULL ) {
		retval = -1;
	}
	return(retval);
}

/* This should never be called...
   If this is called by SDL_Quit(), we don't know whether or not we should
   clean up threads here.  If any threads are still running after this call,
   they will no longer have access to any per-thread data.
 */
void SDL_ThreadsQuit()
{
	SDL_mutex *mutex;

	mutex = thread_lock;
	thread_lock = NULL;
	if ( mutex != NULL ) {
		SDL_DestroyMutex(mutex);
	}
}

/* Routines for manipulating the thread list */
static void SDL_AddThread(SDL_Thread *thread)
{
	SDL_Thread **threads;

	/* WARNING:
	   If the very first threads are created simultaneously, then
	   there could be a race condition causing memory corruption.
	   In practice, this isn't a problem because by definition there
	   is only one thread running the first time this is called.
	*/
	if ( thread_lock == NULL ) {
		if ( SDL_ThreadsInit() < 0 ) {
			return;
		}
	}
	SDL_mutexP(thread_lock);

	/* Expand the list of threads, if necessary */
#ifdef DEBUG_THREADS
	printf("Adding thread (%d already - %d max)\n",
			SDL_numthreads, SDL_maxthreads);
#endif
	if ( SDL_numthreads == SDL_maxthreads ) {
		threads=(SDL_Thread **)malloc((SDL_maxthreads+ARRAY_CHUNKSIZE)*
		                              (sizeof *threads));
		if ( threads == NULL ) {
			SDL_OutOfMemory();
			goto done;
		}
		memcpy(threads, SDL_Threads, SDL_numthreads*(sizeof *threads));
		SDL_maxthreads += ARRAY_CHUNKSIZE;
		if ( SDL_Threads ) {
			free(SDL_Threads);
		}
		SDL_Threads = threads;
	}
	SDL_Threads[SDL_numthreads++] = thread;
done:
	SDL_mutexV(thread_lock);
}

static void SDL_DelThread(SDL_Thread *thread)
{
	int i;

	if ( thread_lock ) {
		SDL_mutexP(thread_lock);
		for ( i=0; i<SDL_numthreads; ++i ) {
			if ( thread == SDL_Threads[i] ) {
				break;
			}
		}
		if ( i < SDL_numthreads ) {
			if ( --SDL_numthreads > 0 ) {
				while ( i < SDL_numthreads ) {
					SDL_Threads[i] = SDL_Threads[i+1];
					++i;
				}
			} else {
				SDL_maxthreads = 0;
				free(SDL_Threads);
				SDL_Threads = NULL;
			}
#ifdef DEBUG_THREADS
			printf("Deleting thread (%d left - %d max)\n",
					SDL_numthreads, SDL_maxthreads);
#endif
		}
		SDL_mutexV(thread_lock);
	}
}

/* The default (non-thread-safe) global error variable */
static SDL_error SDL_global_error;

/* Routine to get the thread-specific error variable */
SDL_error *SDL_GetErrBuf(void)
{
	SDL_error *errbuf;

	errbuf = &SDL_global_error;
	if ( SDL_Threads ) {
		int i;
		Uint32 this_thread;

		this_thread = SDL_ThreadID();
		SDL_mutexP(thread_lock);
		for ( i=0; i<SDL_numthreads; ++i ) {
			if ( this_thread == SDL_Threads[i]->threadid ) {
				errbuf = &SDL_Threads[i]->errbuf;
				break;
			}
		}
		SDL_mutexV(thread_lock);
	}
	return(errbuf);
}


/* Arguments and callback to setup and run the user thread function */
typedef struct {
	int (*func)(void *);
	void *data;
	SDL_Thread *info;
	SDL_sem *wait;
} thread_args;

void SDL_RunThread(void *data)
{
	thread_args *args;
	int (*userfunc)(void *);
	void *userdata;
	int *statusloc;

	/* Perform any system-dependent setup
	   - this function cannot fail, and cannot use SDL_SetError()
	 */
	SDL_SYS_SetupThread();

	/* Get the thread id */
	args = (thread_args *)data;
	args->info->threadid = SDL_ThreadID();

	/* Figure out what function to run */
	userfunc = args->func;
	userdata = args->data;
	statusloc = &args->info->status;

	/* Wake up the parent thread */
	SDL_SemPost(args->wait);

	/* Run the function */
	*statusloc = userfunc(userdata);
}

#ifdef __OS2__
DECLSPEC SDL_Thread * SDLCALL SDL_CreateThread_Core(int (*fn)(void *), void *data, pfnSDL_CurrentBeginThread pfnBeginThread, pfnSDL_CurrentEndThread pfnEndThread)
#else
DECLSPEC SDL_Thread * SDLCALL SDL_CreateThread(int (*fn)(void *), void *data)
#endif
{
	SDL_Thread *thread;
	thread_args *args;
	int ret;

	/* Allocate memory for the thread info structure */
	thread = (SDL_Thread *)malloc(sizeof(*thread));
	if ( thread == NULL ) {
		SDL_OutOfMemory();
		return(NULL);
	}
	memset(thread, 0, (sizeof *thread));
	thread->status = -1;

	/* Set up the arguments for the thread */
	args = (thread_args *)malloc(sizeof(*args));
	if ( args == NULL ) {
		SDL_OutOfMemory();
		free(thread);
		return(NULL);
	}
	args->func = fn;
	args->data = data;
	args->info = thread;
	args->wait = SDL_CreateSemaphore(0);
	if ( args->wait == NULL ) {
		free(thread);
		free(args);
		return(NULL);
	}

	/* Add the thread to the list of available threads */
	SDL_AddThread(thread);

	/* Create the thread and go! */
#ifdef __OS2__
        ret = SDL_SYS_CreateThread(thread, args, pfnBeginThread, pfnEndThread);
#else
	ret = SDL_SYS_CreateThread(thread, args);
#endif
	if ( ret >= 0 ) {
		/* Wait for the thread function to use arguments */
		SDL_SemWait(args->wait);
	} else {
		/* Oops, failed.  Gotta free everything */
		SDL_DelThread(thread);
		free(thread);
		thread = NULL;
	}
	SDL_DestroySemaphore(args->wait);
	free(args);

	/* Everything is running now */
	return(thread);
}

void SDL_WaitThread(SDL_Thread *thread, int *status)
{
	if ( thread ) {
		SDL_SYS_WaitThread(thread);
		if ( status ) {
			*status = thread->status;
		}
		SDL_DelThread(thread);
		free(thread);
	}
}

Uint32 SDL_GetThreadID(SDL_Thread *thread)
{
	Uint32 id;

	if ( thread ) {
		id = thread->threadid;
	} else {
		id = SDL_ThreadID();
	}
	return(id);
}

void SDL_KillThread(SDL_Thread *thread)
{
	if ( thread ) {
		SDL_SYS_KillThread(thread);
		SDL_WaitThread(thread, NULL);
	}
}