Blocks the calling thread until the pollable event is set, and then atomically unsetting the event before returning.
NSPR_API(PRStatus) PR_WaitForPollableEvent(PRFileDesc *event);
The function has the following parameter:
eventPRFileDesc structure previously created via a call to PR_NewPollableEvent.The function returns one of the following values:
PR_SUCCESS.PR_FAILURE. The reason for the failure can be retrieved via PR_GetError.