This chapter describes the NSPR API for using interprocess communication semaphores. NSPR provides an interprocess communication mechanism using a counting semaphore model similar to that which is provided in Unix and Windows platforms. :::{note} **Note:** See also [Named Shared Memory](Named_Shared_Memory) ::: - [IPC Semaphore Functions](#IPC_Semaphore_Functions) (ipc-semaphore-functions)= # IPC Semaphore Functions > - {ref}`PR_OpenSemaphore` > - {ref}`PR_WaitSemaphore` > - {ref}`PR_PostSemaphore` > - {ref}`PR_CloseSemaphore` > - {ref}`PR_DeleteSemaphore`