AcquireWriterLock Method (TimeSpan)
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ReaderWriterLock.AcquireWriterLock Method (TimeSpan)


Acquires the writer lock, using a TimeSpan value for the time-out.

Namespace:   System.Threading
Assembly:  mscorlib (in mscorlib.dll)

public void AcquireWriterLock(
	TimeSpan timeout


Type: System.TimeSpan

The TimeSpan specifying the time-out period.

Exception Condition

timeout expires before the lock request is granted.


timeout specifies a negative value other than -1 milliseconds.

This method blocks if another thread has a reader lock or writer lock. For a description of the way the writer lock alternates with multiple concurrent reader locks, see the ReaderWriterLock class.

A thread that already has a reader lock can acquire the writer lock in one of two ways: by releasing the reader lock before calling AcquireWriterLock, or by calling UpgradeToWriterLock.


If a thread calls AcquireWriterLock while it still has a reader lock, it will block on its own reader lock; if an infinite time-out is specified, the thread will deadlock. To avoid such deadlocks, use IsReaderLockHeld to determine whether the current thread already has a reader lock.

AcquireWriterLock supports recursive writer-lock requests. That is, a thread can call AcquireWriterLock multiple times, which increments the lock count each time. You must call ReleaseWriterLock once for each time you call AcquireWriterLock. Alternatively, you can call ReleaseLock to reduce the lock count to zero immediately.

Recursive lock requests are always granted immediately, without placing the requesting thread in the writer queue.

For valid time-out values, see ReaderWriterLock.

.NET Framework
Available since 1.1
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