multi threading, not unloading threads

External Since: Sep 24, 2005 Posts: 85

ok, i found out that all sounds MUST be played in the main thread for
some reason so here's what i've done

detatch a thread that scans for the sound file and then loads it into an
array

when that thread is finished, it sets a boolean value saying the sound
has been loaded. i then play the sound loaded in the main thread if the
boolean flag is set

it seems to work for me ok but counting the threads, it shouldn't have
more than one thread running while it's playing. i have 9 running now.

is this something else i have to contend with locating?

-(void)playsound
{
if (lastSoundIsValid && !lastSoundIsMovie)
{
[(NSSound *)[soundArray objectAtIndex: [soundArray count] - 1] play];
lastSoundIsPlaying = YES;
}
#if BuildForOSX == 3
else
{
if (lastSoundIsValid)
{
[(QTMovie *)[soundArray objectAtIndex: [soundArray count] - 1]
play];
lastSoundIsPlaying = YES;
}
}
#endif
lastSoundIsValid = NO;
}

-(void)loadsound: (NSString *) soundname;
{
NSAutoreleasePool *pool1 = [[NSAutoreleasePool alloc] init];
isFinishedLoadingSound = NO;
lastSoundIsValid = NO;
lastSoundIsMovie = NO;
NSSound *tempsound;
BOOL isloaded = NO;
NSError *myerror;
myerror = [[NSError alloc] init];
NSMutableString *soundfilename = [[[NSMutableString alloc] init]
autorelease];
[soundfilename setString: [self locateSound: soundname]];
if ([soundfilename length] > 0)
{
if (([soundfilename rangeOfString: @".mp3" options:
NSCaseInsensitiveSearch].location == NSNotFound) && ([soundfilename
rangeOfString: @".m4v" options: NSCaseInsensitiveSearch].location ==
NSNotFound) && ([soundfilename rangeOfString: @".m4b" options:
NSCaseInsensitiveSearch].location == NSNotFound) && ([soundfilename
rangeOfString: @".aac" options: NSCaseInsensitiveSearch].location ==
NSNotFound) && ([soundfilename rangeOfString: @".m4p" options:
NSCaseInsensitiveSearch].location == NSNotFound))
{
[soundArray addObject: [[NSSound alloc] initWithContentsOfFile:
soundfilename byReference:YES]];
NSLog(@"Now playing sound --> %@",soundfilename);
lastSoundIsPlaying = NO;
lastSoundIsValid = YES;
isloaded = YES;
}
#if BuildForOSX == 3
else
{
if ([QTMovie canInitWithFile: soundfilename])
{
[soundArray addObject: [QTMovie movieWithFile: soundfilename
error: &myerror]];
NSLog(@"Now playing sound --> %@",soundfilename);
lastSoundIsValid = YES;
lastSoundIsPlaying = NO;
lastSoundIsMovie = YES;
isloaded = YES;
}
}
#endif
}
else
{
tempsound = [[NSSound soundNamed: soundname] autorelease];
if (tempsound != nil)
{
NSLog(@"Now playing sound --> %@",soundname);
[soundArray addObject: [NSSound soundNamed: soundname]];
lastSoundIsValid = YES;
lastSoundIsPlaying = NO;
isloaded = YES;
}
}
if (!isloaded)
{
NSLog(@"Unable to locate the sound --> %@", soundname);
[yasse_link echoTextToGameScreen: [NSMutableString stringWithString:
[NSString stringWithFormat: @"Unable to locate the sound --> %@\n",
soundname]]];
}
isFinishedLoadingSound = YES;
[pool1 release];
}

-(void)stopPlayingSounds;
{
if ([soundArray count] > 0)
{
[soundArray makeObjectsPerformSelector: @selector(stop)];
[soundArray removeAllObjects];
}
isFinishedLoadingSound = YES;
}

-(BOOL)isPlayingSounds
{
return ([soundArray count] > 0);
}

External Since: Jun 06, 2005 Posts: 660

In article <santa-3BFF26.20344522012007.TakeThisOut@news.giganews.com>,
Santa Claus <santa.TakeThisOut@northpole.com> wrote:

> ok, i found out that all sounds MUST be played in the main thread for
> some reason so here's what i've done

The above is not actually true. What you're probably running into is the
lack of an active run loop in the thread(s) from which you're trying to
play sounds.

> detatch a thread that scans for the sound file and then loads it into an
> array
>
> when that thread is finished, it sets a boolean value saying the sound
> has been loaded. i then play the sound loaded in the main thread if the
> boolean flag is set
>
> it seems to work for me ok but counting the threads, it shouldn't have
> more than one thread running while it's playing. i have 9 running now.
>
> is this something else i have to contend with locating?

On a quick glance through the code, I don't see any real attempt to
prevent multiple sounds from playing at once. I note that the loadsound:
method clears the flag that indicates any sound is playing without
verifying that that's the case. Nothing at all in what you've posted
seems to be looking to see if a sound is already playing.

> -(void)playsound
> {
> if (lastSoundIsValid && !lastSoundIsMovie)
> {
> [(NSSound *)[soundArray objectAtIndex: [soundArray count] - 1] play];
> lastSoundIsPlaying = YES;
> }
> #if BuildForOSX == 3
> else
> {
> if (lastSoundIsValid)
> {
> [(QTMovie *)[soundArray objectAtIndex: [soundArray count] - 1]
> play];
> lastSoundIsPlaying = YES;
> }
> }
> #endif
> lastSoundIsValid = NO;
> }

Here's the same routine, using the knowledge that you control soundArray
and everything you put in it is known to respond to the 'play' message.
You really don't need to care about what type of object it is. And even
if you did, you shouldn't be tracking it in a boolean. You can just
query the object. Otherwise you need to keep an array of booleans that
tracks the array of "sound" objects, right?

- (void)playSound
{
if(lastSoundIsValid)
{
[[soundArray lastObject]play];
lastSoundIsPlaying = YES;
lastSoundIsValid = NO;
}
}

> -(void)loadsound: (NSString *) soundname;
> {
> NSAutoreleasePool *pool1 = [[NSAutoreleasePool alloc] init];
> isFinishedLoadingSound = NO;
> lastSoundIsValid = NO;
> lastSoundIsMovie = NO;
> NSSound *tempsound;
> BOOL isloaded = NO;
> NSError *myerror;
> myerror = [[NSError alloc] init];
> NSMutableString *soundfilename = [[[NSMutableString alloc] init]
> autorelease];
> [soundfilename setString: [self locateSound: soundname]];
> if ([soundfilename length] > 0)
> {
> if (([soundfilename rangeOfString: @".mp3" options:
> NSCaseInsensitiveSearch].location == NSNotFound) && ([soundfilename
> rangeOfString: @".m4v" options: NSCaseInsensitiveSearch].location ==
> NSNotFound) && ([soundfilename rangeOfString: @".m4b" options:
> NSCaseInsensitiveSearch].location == NSNotFound) && ([soundfilename
> rangeOfString: @".aac" options: NSCaseInsensitiveSearch].location ==
> NSNotFound) && ([soundfilename rangeOfString: @".m4p" options:
> NSCaseInsensitiveSearch].location == NSNotFound))
> {
> [soundArray addObject: [[NSSound alloc] initWithContentsOfFile:
> soundfilename byReference:YES]];
> NSLog(@"Now playing sound --> %@",soundfilename);
> lastSoundIsPlaying = NO;
> lastSoundIsValid = YES;
> isloaded = YES;
> }
> #if BuildForOSX == 3
> else
> {
> if ([QTMovie canInitWithFile: soundfilename])
> {
> [soundArray addObject: [QTMovie movieWithFile: soundfilename
> error: &myerror]];
> NSLog(@"Now playing sound --> %@",soundfilename);
> lastSoundIsValid = YES;
> lastSoundIsPlaying = NO;
> lastSoundIsMovie = YES;
> isloaded = YES;
> }
> }
> #endif
> }
> else
> {
> tempsound = [[NSSound soundNamed: soundname] autorelease];
> if (tempsound != nil)
> {
> NSLog(@"Now playing sound --> %@",soundname);
> [soundArray addObject: [NSSound soundNamed: soundname]];
> lastSoundIsValid = YES;
> lastSoundIsPlaying = NO;
> isloaded = YES;
> }
> }
> if (!isloaded)
> {
> NSLog(@"Unable to locate the sound --> %@", soundname);
> [yasse_link echoTextToGameScreen: [NSMutableString stringWithString:
> [NSString stringWithFormat: @"Unable to locate the sound --> %@\n",
> soundname]]];
> }
> isFinishedLoadingSound = YES;
> [pool1 release];
> }

Specific comments / study questions:
1. Why are you creating your mutable string with alloc/init/autorelease
instead of just [NSMutableString string]?
2. Why are you setting the already allocated string instead of just
declaring it and assigning it the result of locateSound:?
3. Why is it an NSMutableString instead of an NSString if you never
mutate it? Even if you're going to do the copy I wonder about in
question 2, you can initialize a string with a string instead of
creating it and then setting it after the fact.
4. Why are you using NSMovie for some types that are purely audio and
handled by NSSound?
5. What's going to happen if my some weird quirk you get a sound file
named "foo.mp3.aiff"?
6. isFinishedLoadingSound really needs to be protected by a lock if
that's your thread serialization flag.

You've got a few memory errors in there. When locateSound: succeeds and
gives you back something that goes through NSSound you add an
alloc/inited sound directly to an array. That instance will leak,
because you never give up the implicit reference count from the
alloc/init operation. In the tempsound section, on the other hand, you
autorelease something that's already autoreleased. That's likely to
crash. You don't need to allocate the NSError you're passing to
movieWithFile:error:. That'll leak. Then again you never do anything
with the error, so you might as well just pass nil.

I think the following code does the same thing as yours, minus the
outright errors but retaining some things that I consider suspect
because I can't tell for sure outside the context of your program.

- (void)loadSound:(NSString*)inSoundName
{
BOOL isLoaded = NO;
isFinishedLoadingSound = NO;
lastSoundIsValid = NO;
NSAutoreleasePool* thePool = [[NSAutoreleasePool alloc] init];
NSArray* theMovieTypes = [NSArray arrayWithObjects:@"MP3", @"M4V",
@"M4B", @"AAC", @"M4P", nil];
NSString* theSoundPath = [self locateSound:inSoundName];
id theSound = nil;
if([theSoundPath length] > 0)
{
NSString* theExtension = [theSoundPath pathExtension];
if([theMovieTypes indexOfObject:[theExtension uppercaseString] ==
NSNotFound)
{
theSound = [[NSSound alloc] initWithContentsOfFile:theSoundPath
byReference:YES];
[theSound autorelease];
}
else
{
if([QTMovie canInitWithFile:theSoundPath])
{
theSound = [QTMovie movieWithFile:theSoundPath error:nil];
}
}
}
else
{
theSound = [NSSound soundNamed:soundname];
}
if(theSound)
{
[soundArray addObject:theSound];
lastSoundIsValid = YES;
lastSoundIsPlaying = NO;
}
else
{
[yasse_link echoTextToGameScreen:[NSString stringWithFormat:
@"Unable to locate the sound --> %@\n", soundname]];
}
isFinishedLoadingSound = YES;
[thePool release];
}

>
> -(void)stopPlayingSounds;
> {
> if ([soundArray count] > 0)
> {
> [soundArray makeObjectsPerformSelector: @selector(stop)];
> [soundArray removeAllObjects];
> }
> isFinishedLoadingSound = YES;
> }
>
> -(BOOL)isPlayingSounds
> {
> return ([soundArray count] > 0);
> }

--
The best intentions in the world don't make a flawed argument magically valid.