class
	CONDITION_VARIABLE

General
	cluster: ise
	description: 
		"Condition variables allow threads to synchronize based on the content of a shared data, whereas
		mutexes only synchronize access to the data. In other words, a condition variable is a
		synchronization object that enables threads to wait until a particular condition occurs.
		
		When a thread executes a wait call on a condition variable, it must hold an associated mutex
		(used for checking that condition). Then, it is immediately suspended and put into the waiting
		queue. The thread is suspended and is waiting for the condition to occur.
		
		Eventually, when the condition has occurred, a thread will signal it. Two possible scenarios:
		- if there are threads waiting, then one of the waiting thread will resume its execution and
		  will get the mutex in a locked state.
		- if there are no threads waiting, nothing is done
		
		For the simple usage of a condition variable, it is very similar to using a semaphore.
		
		In addition you have broadcast that will resume all waiting threads at once, and
		wait_with_timeout that will wait only a certain amount of time before abandonning the wait.
		
		The signal and broadcast routines can be called by a thread whether or not it currently owns
		the mutex that threads calling wait or wait_with_timeout have associated with the condition
		variable during their waits. If, however, predictable scheduling behavior is required, then that
		mutex should be locked by the thread prior to calling signal or broadcast.
		
		Assuming shared_data an INTEGER initially set to zero, then a typical usage of condition variable
		to wait until shared_data becomes one, could be written as followed in thread A:
		
		mutex.lock
		from
		until
		shared_data = 1
		loop
		condition_variable.wait (mutex)
		end
		mutex.unlock
		
		and in thread B:
		
		mutex.lock
		shared_data := 1
		condition_variable.signal
		mutex.unlock
		
		Thread A will be blocked until thread B signal that now shared_data is 1."
	create: make

Ancestors
	DISPOSABLE*

Queries
	is_set: BOOLEAN
	wait_with_timeout (a_mutex: MUTEX; a_timeout_ms: INTEGER_32): BOOLEAN

Commands
	broadcast
	destroy
	dispose
	signal
	wait (a_mutex: MUTEX)

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