func (cp *compiler) pipeline(n *parse.Pipeline) OpFunc { ops := cp.formOps(n.Forms) return func(ec *EvalCtx) { bg := n.Background if bg { ec = ec.fork("background job " + n.SourceText()) ec.intCh = nil ec.background = true if ec.Editor != nil { // TODO: Redirect output in interactive mode so that the line // editor does not get messed up. } } nforms := len(ops) var wg sync.WaitGroup wg.Add(nforms) errors := make([]Error, nforms) var verdict bool var nextIn *Port // For each form, create a dedicated evalCtx and run asynchronously for i, op := range ops { newEc := ec.fork(fmt.Sprintf("form op %v", op)) if i > 0 { newEc.ports[0] = nextIn } if i < nforms-1 { // Each internal port pair consists of a (byte) pipe pair and a // channel. // os.Pipe sets O_CLOEXEC, which is what we want. reader, writer, e := os.Pipe() if e != nil { throwf("failed to create pipe: %s", e) } ch := make(chan Value, pipelineChanBufferSize) newEc.ports[1] = &Port{ File: writer, Chan: ch, CloseFile: true, CloseChan: true} nextIn = &Port{ File: reader, Chan: ch, CloseFile: true, CloseChan: false} } thisOp := op thisError := &errors[i] isLast := i == nforms-1 go func() { err := newEc.PEval(thisOp) // Logger.Printf("closing ports of %s", newEc.context) ClosePorts(newEc.ports) if isLast { verdict = newEc.verdict } *thisError = Error{err} wg.Done() }() } if bg { // Background job, wait for form termination asynchronously. go func() { wg.Wait() msg := "job " + n.SourceText() + " finished" if !allok(errors) { msg += ", errors = " + makeCompositeError(errors).Error() } if !verdict { msg += ", pred = false" } if ec.Editor != nil { m := ec.Editor.ActiveMutex() m.Lock() defer m.Unlock() if ec.Editor.Active() { ec.Editor.Notify("%s", msg) } else { ec.ports[2].File.WriteString(msg) } } else { ec.ports[2].File.WriteString(msg) } }() } else { wg.Wait() maybeThrow(makeCompositeError(errors)) ec.verdict = verdict } } }