Condition variables to synchronize between threads.
Condition variable type. The type parameter denotes the type of value propagated from notifier to waiter.
wait mutex condvar will cause the current thread to block,
awaiting notification for a condition variable,
mutex must have been previously locked (within
the scope of
Lwt_mutex.with_lock, for example) and is
temporarily unlocked until the condition is notified. Upon
mutex is re-locked before
wait returns and
the thread's activity is resumed. When the awaited condition
is notified, the value parameter passed to
signal condvar value notifies that a condition is ready. A
single waiting thread will be awoken and will receive the
notification value which will be returned from
that condition notification is not "sticky", i.e. if there is
no waiter when
notify is called, the notification will be
missed and the value discarded.