xnu-6153.11.26.tar.gz

[apple/xnu.git] / iokit / IOKit / IOLocks.h

diff --git a/iokit/IOKit/IOLocks.h b/iokit/IOKit/IOLocks.h
index 2c89a177aec40c15939b24316dc35e30c949fef4..88242c940413a5f3cf7a2abe109e0c5987e49885 100644 (file)
--- a/iokit/IOKit/IOLocks.h
+++ b/iokit/IOKit/IOLocks.h
@@ -401,11 +401,18 @@ lck_spin_t * IOSimpleLockGetMachLock( IOSimpleLock * lock);
 
 /*! @function IOSimpleLockInit
  *   @abstract Initialize a spin lock.
- *   @discussion Initialize an embedded spin lock, to the unlocked state.
+ *   @discussion Initialize a non heap allocated spin lock to the unlocked state. Use this function when your lock is, for example, a member variable. You will need to call IOSimpleLockDestroy when you are finished with the lock to avoid lock group refcount leaks.
  *   @param lock Pointer to the lock. */
 
 void IOSimpleLockInit( IOSimpleLock * lock );
 
+/*! @function IOSimpleLockDestroy
+ *   @abstract De-initializes (destroys) a spin lock initialized with IOSimpleLockInit
+ *   @discussion Destroy / De-initialize a non heap allocated spin lock, releasing any system resources such as lock group refcounts.
+ *   @param lock Pointer to the lock. */
+
+void IOSimpleLockDestroy( IOSimpleLock * lock );
+
 /*! @function IOSimpleLockLock
  *   @abstract Lock a spin lock.
  *  @discussion Lock the spin lock. If the lock is held, spin waiting for its unlock. Spin locks disable preemption, cannot be held across any blocking operation, and should be held for very short periods. When used to synchronize between interrupt context and thread context they should be locked with interrupts disabled - IOSimpleLockLockDisableInterrupt() will do both. Locking the lock recursively from one thread will result in deadlock.