monitor(@optional name = void)
Return a new monitor.
A monitor represents a set of blocked tasks. These blocked tasks are waiting for a certain
condition to become true. When a task modifies some program state that might make
the condition true, the task unblocks some number of tasks (one or all depending on the primitive used)
so they can check if the condition is now true. This allows complex forms of intertask
synchronization to be expressed more conveniently than with mutexes alone.
Each monitor has a specific field which can be used in an application specific way to associate data with the condition variable.
let mx, mn = mutex(), monitor()
!{ mutex_lock(mx)
mutex_unlock(mx, mn)
showln("done...") }
!{ mutex_lock(mx)
mutex_unlock(mx, mn)
showln("bye.") }
!monitor_broadcast(mn)
//> done...
bye.