Semaphore Services

These services are used to synchronize a virtual device driver with another OS/2 process. If a virtual device driver blocks a VDM process, that VDM will not receive any simulated hardware interrupts until it becomes unblocked. VDH semaphore services are used to handle the following:

  • Mutual exclusion and event semaphores
  • OS/2 process to physical device driver communication
  • Virtual device driver/physical device driver communication
  • VDM event list management.

    [Back: Memory Management]
    [Next: Freeze/Thaw Services]