Term

Definition

block ID

A programmer-defined 32-bit value associated with one or more blocked threads.

claim

A request on the part of a virtual device to enter a critical section.

claim count

A system-defined variable that indicates the number of times the owner of a critical section has claimed the section.

context switch

The act of turning the CPU's "attention" from one thread to another.

critical section

A block of program code that accesses a shared system resource.

critical section owner

The thread or virtual machine that is currently executing in a critical section.

must-complete count

A system-defined variable that indicates the number of times the owner of a must-complete section has claimed the section.

must-complete section

A block of code that must be executed in its entirety before any other thread or virtual machine can run.

mutex

A synchronization object that ensures only one thread at a time can access a shared resource. A thread must have ownership of the mutex before it can access the resource. The thread blocks if the mutex is owned by another thread.

reentry count

A system-defined variable that indicates the number of times the owner of a mutex has called the _EnterMutex service after gaining ownership.

semaphore

An synchronization object that maintains a token count between zero and some maximum value. The object's state is signaled when its token count is greater than zero, and not-signaled when its count is zero.

signal

To increase the token count of a semaphore.

semaphore token count

The value associated with a semaphore. The initial token count is set when the semaphore is created. A signal operation increments the token count, and a wait operation decrements it.