The ENGSAFESEMAPHORE structure provides the driver with a thread-safe semaphore.
Handle to the semaphore.
Specifies the reference count on the semaphore.
A safe semaphore is a wrapper that contains a handle to a semaphore and a reference count on that semaphore.
The driver allocates an ENGSAFESEMAPHORE structure and passes it to EngInitializeSafeSemaphore for initialization. GDI operates the safe semaphore under a lock and maintains a reference count on it, making it suitable for multithreading.
Build date: 1/22/2014