Merge branch '8784-dir-listings'

[arvados.git] / services / crunch-dispatch-slurm / squeue.go

diff --git a/services/crunch-dispatch-slurm/squeue.go b/services/crunch-dispatch-slurm/squeue.go
index c1bbe920ede523850a07fdc578103097b53f3650..d22e02597b75d5d5d7a0b74599cc4d142d002345 100644 (file)
--- a/services/crunch-dispatch-slurm/squeue.go
+++ b/services/crunch-dispatch-slurm/squeue.go
@@ -1,3 +1,7 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
 package main
 
 import (
@@ -11,9 +15,9 @@ import (
 
 // Squeue implements asynchronous polling monitor of the SLURM queue using the
 // command 'squeue'.
-type Squeue struct {
+type SqueueChecker struct {
        Period    time.Duration
-       hasUUID   map[string]bool
+       uuids     map[string]bool
        startOnce sync.Once
        done      chan struct{}
        sync.Cond
@@ -28,35 +32,35 @@ var squeueCmd = squeueFunc
 // HasUUID checks if a given container UUID is in the slurm queue.
 // This does not run squeue directly, but instead blocks until woken
 // up by next successful update of squeue.
-func (squeue *Squeue) HasUUID(uuid string) bool {
-       squeue.startOnce.Do(squeue.start)
+func (sqc *SqueueChecker) HasUUID(uuid string) bool {
+       sqc.startOnce.Do(sqc.start)
 
-       squeue.L.Lock()
-       defer squeue.L.Unlock()
+       sqc.L.Lock()
+       defer sqc.L.Unlock()
 
        // block until next squeue broadcast signaling an update.
-       squeue.Wait()
-       return squeue.hasUUID[uuid]
+       sqc.Wait()
+       return sqc.uuids[uuid]
 }
 
 // Stop stops the squeue monitoring goroutine. Do not call HasUUID
 // after calling Stop.
-func (squeue *Squeue) Stop() {
-       if squeue.done != nil {
-               close(squeue.done)
+func (sqc *SqueueChecker) Stop() {
+       if sqc.done != nil {
+               close(sqc.done)
        }
 }
 
 // check gets the names of jobs in the SLURM queue (running and
-// queued). If it succeeds, it updates squeue.hasUUID and wakes up any
-// goroutines that are waiting in HasUUID().
-func (squeue *Squeue) check() {
+// queued). If it succeeds, it updates squeue.uuids and wakes up any
+// goroutines that are waiting in HasUUID() or All().
+func (sqc *SqueueChecker) check() {
        // Mutex between squeue sync and running sbatch or scancel.  This
        // establishes a sequence so that squeue doesn't run concurrently with
        // sbatch or scancel; the next update of squeue will occur only after
        // sbatch or scancel has completed.
-       squeue.L.Lock()
-       defer squeue.L.Unlock()
+       sqc.L.Lock()
+       defer sqc.L.Unlock()
 
        cmd := squeueCmd()
        stdout, stderr := &bytes.Buffer{}, &bytes.Buffer{}
@@ -67,28 +71,42 @@ func (squeue *Squeue) check() {
        }
 
        uuids := strings.Split(stdout.String(), "\n")
-       squeue.hasUUID = make(map[string]bool, len(uuids))
+       sqc.uuids = make(map[string]bool, len(uuids))
        for _, uuid := range uuids {
-               squeue.hasUUID[uuid] = true
+               sqc.uuids[uuid] = true
        }
-       squeue.Broadcast()
+       sqc.Broadcast()
 }
 
 // Initialize, and start a goroutine to call check() once per
 // squeue.Period until terminated by calling Stop().
-func (squeue *Squeue) start() {
-       squeue.L = &sync.Mutex{}
-       squeue.done = make(chan struct{})
+func (sqc *SqueueChecker) start() {
+       sqc.L = &sync.Mutex{}
+       sqc.done = make(chan struct{})
        go func() {
-               ticker := time.NewTicker(squeue.Period)
+               ticker := time.NewTicker(sqc.Period)
                for {
                        select {
-                       case <-squeue.done:
+                       case <-sqc.done:
                                ticker.Stop()
                                return
                        case <-ticker.C:
-                               squeue.check()
+                               sqc.check()
                        }
                }
        }()
 }
+
+// All waits for the next squeue invocation, and returns all job
+// names reported by squeue.
+func (sqc *SqueueChecker) All() []string {
+       sqc.startOnce.Do(sqc.start)
+       sqc.L.Lock()
+       defer sqc.L.Unlock()
+       sqc.Wait()
+       var uuids []string
+       for uuid := range sqc.uuids {
+               uuids = append(uuids, uuid)
+       }
+       return uuids
+}