Tries to enter the lock in upgradeable mode, with an optional time-out.
Syntax
Parameters
- timeout
Returns
true if the calling thread entered upgradeable mode, otherwise, false.
Remarks
If timeout is 0 (zero), this method checks the lock state and returns false immediately if the desired state is unavailable.
Use upgradeable mode when a thread usually accesses the resource protected by the System.Threading.ReaderWriterLockSlim in read mode, but may need to enter write mode if certain conditions are met. A thread in upgradeable mode can upgrade to write mode or downgrade to read mode.
Only one thread can enter a lock in upgradeable mode at any given time. If a thread is in upgradeable mode, and there are no threads waiting to enter write mode, any number of other threads can enter read mode, even if there are threads waiting to enter upgradeable mode.
If one or more threads are waiting to enter write mode, a thread that calls the ReaderWriterLockSlim.TryEnterUpgradeableReadLock(int) method blocks until those threads have either timed out or entered write mode and then exited from it, or until the calling thread's own time-out interval expires.
If a lock allows recursion, a thread that has entered the lock in upgradeable mode can enter upgradeable mode recursively, even if other threads are waiting to enter write mode.
Requirements
Assembly: System.Core (in System.Core.dll)
Assembly Versions: 4.0.0.0