MulleObject

Base class that provides automatic thread-safe method locking in mulle-objc. Inherits from MulleDynamicObject and adds recursive locking capabilities.

Base Class

MulleDynamicObject

Implemented Protocols

• NSLocking
• MulleAutolockingObject (optional)

Instance Variables

NSRecursiveLock   *__lock;  // Recursive lock for thread safety

Methods

Object Creation

• +locklessObject - Creates instance without lock
• -initNoLock - Initializes without lock
• -init - Initializes with lock

Lock Operations (NSLocking)

• -lock - Acquires the lock
• -unlock - Releases the lock
• -tryLock - Attempts to acquire lock without blocking

Lock Sharing

• -didShareRecursiveLock: - Called after lock sharing to update thread affinity
• -shareRecursiveLock: - Shares lock with another lock
• -shareRecursiveLockWithObject: - Shares lock with another MulleObject

Internal Forwarding

• -__lockingForward: - Handles locking for forwarded methods
• -__lockingSuperForward: - Handles locking for super forwarded methods

Usage Example

// Create thread-safe object
@interface MyObject : MulleObject <MulleAutolockingObjectProtocols>
@end

// Create lockless object
MyObject *obj = [MyObject locklessObject];

// Share lock between objects
MyObject *obj2 = [MyObject new];
[obj2 shareRecursiveLockWithObject:obj];

// Methods are automatically locked
[obj doSomething];  // Thread-safe

Important Notes

1. Thread Safety
   • Methods are automatically locked when MulleAutolockingObject protocol is used
   • Lock sharing allows object hierarchies to share synchronization
   • Lockless objects are thread-affine until given a lock
2. Implementation Details
   • Uses NSRecursiveLock for thread safety
   • Caches method lookups for performance
   • Handles exceptions to prevent deadlocks
   • Supports both locked and lockless instances
3. Subclassing
   • Use MulleAutolockingObjectProtocols for thread safety
   • Override didShareRecursiveLock: carefully
   • Call [super didShareRecursiveLock:] when overriding
4. Cache Management
   • Maintains separate caches for thread-safe methods
   • Automatically invalidates caches when needed
   • Optimizes method lookup performance