+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
package main
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
// 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{}
}
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
+}