harness-drone/scheduler/queue/queue.go
2019-02-28 16:23:06 -08:00

252 lines
4.9 KiB
Go

// Copyright 2019 Drone IO, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package queue
import (
"context"
"sync"
"time"
"github.com/drone/drone/core"
)
type queue struct {
sync.Mutex
ready chan struct{}
paused bool
interval time.Duration
store core.StageStore
workers map[*worker]struct{}
ctx context.Context
}
// newQueue returns a new Queue backed by the build datastore.
func newQueue(store core.StageStore) *queue {
q := &queue{
store: store,
ready: make(chan struct{}, 1),
workers: map[*worker]struct{}{},
interval: time.Minute,
ctx: context.Background(),
}
go q.start()
return q
}
func (q *queue) Schedule(ctx context.Context, stage *core.Stage) error {
select {
case q.ready <- struct{}{}:
default:
}
return nil
}
func (q *queue) Pause(ctx context.Context) error {
q.Lock()
q.paused = true
q.Unlock()
return nil
}
func (q *queue) Paused(ctx context.Context) (bool, error) {
q.Lock()
paused := q.paused
q.Unlock()
return paused, nil
}
func (q *queue) Resume(ctx context.Context) error {
q.Lock()
q.paused = false
q.Unlock()
select {
case q.ready <- struct{}{}:
default:
}
return nil
}
func (q *queue) Request(ctx context.Context, params core.Filter) (*core.Stage, error) {
w := &worker{
os: params.OS,
arch: params.Arch,
kernel: params.Kernel,
variant: params.Variant,
labels: params.Labels,
channel: make(chan *core.Stage),
}
q.Lock()
q.workers[w] = struct{}{}
q.Unlock()
select {
case q.ready <- struct{}{}:
default:
}
select {
case <-ctx.Done():
q.Lock()
delete(q.workers, w)
q.Unlock()
return nil, ctx.Err()
case b := <-w.channel:
return b, nil
}
}
func (q *queue) signal(ctx context.Context) error {
q.Lock()
count := len(q.workers)
pause := q.paused
q.Unlock()
if pause {
return nil
}
if count == 0 {
return nil
}
items, err := q.store.ListIncomplete(ctx)
if err != nil {
return err
}
q.Lock()
defer q.Unlock()
for _, item := range items {
if item.Status == core.StatusRunning {
continue
}
if item.Machine != "" {
continue
}
// if the stage defines concurrency limits we
// need to make sure those limits are not exceeded
// before proceeding.
if withinLimits(item, items) == false {
continue
}
loop:
for w := range q.workers {
// the worker is platform-specific. check to ensure
// the queue item matches the worker platform.
if w.os != item.OS {
continue
}
if w.arch != item.Arch {
continue
}
// if the pipeline defines a variant it must match
// the worker variant (e.g. arm6, arm7, etc).
if item.Variant != "" && item.Variant != w.variant {
continue
}
// if the pipeline defines a kernel version it must match
// the worker kernel version (e.g. 1709, 1803).
if item.Kernel != "" && item.Kernel != w.kernel {
continue
}
if len(item.Labels) > 0 || len(w.labels) > 0 {
if !checkLabels(item.Labels, w.labels) {
continue
}
}
// // the queue has 60 seconds to ack the item, otherwise
// // it is eligible for processing by another worker.
// // item.Expires = time.Now().Add(time.Minute).Unix()
// err := q.store.Update(ctx, item)
// if err != nil {
// log.Ctx(ctx).Warn().
// Err(err).
// Int64("build_id", item.BuildID).
// Int64("stage_id", item.ID).
// Msg("cannot update queue item")
// continue
// }
select {
case w.channel <- item:
delete(q.workers, w)
break loop
}
}
}
return nil
}
func (q *queue) start() error {
for {
select {
case <-q.ctx.Done():
return q.ctx.Err()
case <-q.ready:
q.signal(q.ctx)
case <-time.After(q.interval):
q.signal(q.ctx)
}
}
}
type worker struct {
os string
arch string
kernel string
variant string
labels map[string]string
channel chan *core.Stage
}
type counter struct {
counts map[string]int
}
func checkLabels(a, b map[string]string) bool {
if len(a) != len(b) {
return false
}
for k, v := range a {
if w, ok := b[k]; !ok || v != w {
return false
}
}
return true
}
func withinLimits(stage *core.Stage, siblings []*core.Stage) bool {
if stage.Limit == 0 {
return true
}
count := 0
for _, sibling := range siblings {
if sibling.RepoID != stage.RepoID {
continue
}
if sibling.ID == stage.ID {
continue
}
if sibling.Name != stage.Name {
continue
}
if sibling.ID < stage.ID {
count++
}
}
return count < stage.Limit
}