The SafeDispatch framework is a Cocoa wrapper for Grand Central Dispatch that adds important safety features. Not all of GCD is included – the main focus is on improving dispatch queues and groups.
This framework is no longer supported, and is hard to use correctly. If you're looking for a better way to do concurrency, check out ReactiveCocoa instead.
Besides an easy-to-use Objective-C API, this framework adds:
- Recursive synchronous dispatch.
dispatch_sync()deadlocks when targeting the current queue –SDQueuedoes not. - Conditionally asynchronous or synchronous dispatch. Blocks can be run synchronously if targeting the current queue, or asynchronously if targeting another.
- Exception-safe synchronous dispatch, to support throwing exceptions from synchronous blocks and propagating them to callers.
- Synchronization across multiple queues, based on a deterministic total ordering of the queues (to prevent deadlocks).
- Prologue and epilogue blocks, to perform work before or after each block added to a queue.
- Better detection of the current queue. SafeDispatch can identify whether code is executing on a given queue even if that queue is many layers up the call stack. (This is especially important for recursive and conditional dispatch.)
Copyright (c) 2012 Justin Spahr-Summers
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