Developing Drivers with the Windows® Driver Foundation

When Synchronization Is Required

Synchronization ensures that only one thread can access shared data at a single time and prevents the preemption or interruption of a driver thread during critical operations. Synchronization is required for the following:

• Any shared data that multiple threads might access, unless all threads access it in a read-only manner.

• Any operation that involves several actions that must be performed in an uninterruptible, atomic sequence because another thread might use or change data or resources that the operation requires.

On a preemptible, multitasking system such as Windows, one thread can preempt another at any given time. Therefore, these synchronization requirements apply to single-processor systems and to multiprocessor ...