iOS GCD - Set max concurrent operations for a queue

[dantastic]

I'm currently using a dispatch queue to concurrently process and save images taken by the camera in my app.

I need to be able to limit the number of concurrent operations or the app can run out of memory. I know I can set max number of concurrent operations for a NSOperationQueue but I have not been able to find any info regarding dispatch blocks...

// the queue I need to limit
imageProcessingQueue = dispatch_queue_create("com.app.imageProcessingQueue", DISPATCH_QUEUE_CONCURRENT);


- (void) saveImage:(UIImage *)image {
	
	dispatch_async(imageProcessingQueue, ^{
		
		// Process the image and save to disk.
		
		dispatch_async(dispatch_get_main_queue(), ^{
			
			// Save the image path and other image info to core data.
		});
	});
}

 

[Mark FX]

I was reading this Apple documentation the other week myself, and I remember there being a fair bit of information on Dispatch queues.

https://developer.apple.com/library/ios/documentation/General/Conceptual/ConcurrencyProgrammingGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40008091-CH1-SW1

Regards Mark

 

[dantastic]

Thanks for that but in this particular instance there's another answer.
If you need a NSOperationQueue, use a NSOperationQueue.

By using NSOperationQueue's addOperationWithBlock I was able to use the existing code pretty much and it works great