4 Returns the value of the environment variable.
14 NSPR_API(PRStatus) PR_WaitSemaphore(PRSem *sem);
20 The function has the following parameter:
23 A pointer to a ``PRSem`` structure returned from a call to
24 :ref:`PR_OpenSemaphore`.
36 :ref:`PR_WaitSemaphore` tests the value of the semaphore. If the value of
37 the semaphore is > 0, the value of the semaphore is decremented and the
38 function returns. If the value of the semaphore is 0, the function
39 blocks until the value becomes > 0, then the semaphore is decremented
40 and the function returns.
42 The "test and decrement" operation is performed atomically.