SpinLock is a non-reentrant lock, meaning that if a thread holds the lock, it is not allowed to enter the lock again. If thread ownership tracking is enabled (whether it's enabled is available through IsThreadOwnerTrackingEnabled), an exception will be thrown when a thread tries to re-enter a lock it already holds. However, if thread ownership tracking is disabled, attempting to enter a lock already held will result in deadlock.
If you call Exit without having first called Enter the internal state of the SpinLock can become corrupted.
Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)