critical_section.go

func CriticalDataManager(cmdchan chan CriticalCommand) {
    queued := new(vector.Vector)
    critical := 0
    for {
        var rawcmd CriticalCommand
        if critical == 0 && queued.Len() > 0 {
            // Process the queued-up commands when we aren't in critical section
            rawcmd := queued.At(0)
            queued.Delete(0)
        } else {
            // Get new commands when the queue is empty
            rawcmd = <-cmdchan
            if closed(rawcmd) {
                break
            }
        }
        // Queue up commands not from the critical sender when in critical section
        if critical != 0 && rawcmd.Sender() != critical {
            queued.Push(rawcmd)
            continue
        }
        // Process commands
        switch cmd := rawcmd.(type) {
        case CriticalSectionBegin:
            critical = cmd.sender // enter critical section
        case CriticalSectionEnd:
            critical = 0 // exit critical section
        case ...
        }
        rawcmd.Result() <- true
    }
}