Class: ConditionVariable

Relationships & Source Files
Inherits:	Object
Defined in:	thread_sync.c, thread_sync.c

Overview

ConditionVariable objects augment class ::Mutex. Using condition variables, it is possible to suspend while in the middle of a critical section until a resource becomes available.

Example:

require 'thread'

mutex = Mutex.new
resource = ConditionVariable.new

a = Thread.new {
   mutex.synchronize {
     # Thread 'a' now needs the resource
     resource.wait(mutex)
     # 'a' can now have the resource
   }
}

b = Thread.new {
   mutex.synchronize {
     # Thread 'b' has finished using the resource
     resource.signal
   }
}

Class Method Summary

.new constructor

Creates a new condition variable instance.

Instance Method Summary

#broadcast

Wakes up all threads waiting for this lock.
#signal

Wakes up the first thread in line waiting for this lock.
#wait(mutex, timeout = nil)

Releases the lock held in mutex and waits; reacquires the lock on wakeup.

Constructor Details

.new

Creates a new condition variable instance.

Instance Method Details

#broadcast

Wakes up all threads waiting for this lock.

#signal

Wakes up the first thread in line waiting for this lock.

#wait(mutex, timeout = nil)

Releases the lock held in mutex and waits; reacquires the lock on wakeup.

If timeout is given, this method returns after timeout seconds passed, even if no other thread doesn't signal.