wait

#wait

##Syntax A waitStatement is:

wait variableReference [ , expn ]

##Description The wait statement is used in a concurrent program to cause the executing process to be blocked (to go to sleep) until it is awakened by a signal statement. The statement can only be used inside a monitor (a special kind of module that handles concurrency). A wait statement operates on a condition variable (the variableReference), which is essentially a queue of sleeping processes. See condition for an example of a wait statement.

##Details A wait statement for a priority condition must include the optional expn,. This expression must be a non-negative int value which is used to order processes waiting for the condition, low numbers first.

A wait statement for a timeout condition must include the optional expn, which must be a non-negative int value which gives the timeout interval. A process waiting for a timeout condition is implicitly awakened if it waits longer than its timeout interval.

##See also condition.html and signal.html. See also monitor.html and fork.html. See also empty.html. See also pause.html.