Metered concurrency: Difference between revisions

=={{header|J}}==

This implementation, while sufficient for this task's requirements, is for demonstration purposes only, and is not meant for serious work.

<lang J>scheduledumb=: {{

id=:'dumb',":x:6!:9''

wd 'pc ',id

(t)=: u {{u 0{::n[y[erase 1{::n}} (y;t=. id,'_timer')

wd 'ptimer ',":?100

}}

sleep=: 6!:3 NB. seconds

timestamp=: 6!:1 NB. seconds

acquire=: {{

imprison y

while. 1<count y do.

release y

sleep 0.1

imprison y

end.

}}

release=: {{ counter=: (<:y{counter) y} counter }}

imprison=: {{ counter=: (>:y{counter) y} counter }}

count=: {{ y { counter }}

counter=: 0 0

demo=: {{

acquire 0

echo 'unit ',y,&":' acquired semaphore, t=',":timestamp''

sleep 2

release 0

}}</lang>

Task example:

<lang J> demo scheduledumb"0 i.5

unit 1 acquired semaphore, t=54683.6

unit 0 acquired semaphore, t=54685.6

unit 4 acquired semaphore, t=54687.7

unit 2 acquired semaphore, t=54689.7

unit 3 acquired semaphore, t=54691.7</lang>