Ftr: ConnectionPool (#66)

* ftr: work pool

* rename WorkerPool -> FixedWorkerPool

* go fmt

* fix typo

* benchmark for ConnectionPool

* go fmt

* benchmark for ConnectionPool

* chan buffer extension for ConnectionPool benchmark

* reset benchmark tests for TaskPool

* reduce buffer of ConnectionPool

* unbounded chan benchmark

* reduce goroutine num

* ConnectionPool adopts task queue array

* apache license

* fix shadow variable

* remove done channel, add numWorkers

* go fmt

* fix wrong logger

* add newBaseWorkerPool

* remove ConnectionPoolConfig

* update comments

* update comments

* fix unittests

* Update base_worker_pool.go

* Update base_worker_pool.go

* fix newBaseWorkerPool bugs

* go fmt

* fix CountTaskSync bugs

* fix CountTask bug

* optimize code

* go fmt

* add SubmitSync test

* go fmt

Co-authored-by: Xin.Zh <dragoncharlie@foxmail.com>

container/chan/unbounded_chan_test.go

@@ -115,28 +115,19 @@ func testQuota1(t *testing.T) {
 		ch.In() <- i
 	}
 
-	assert.True(t, 15 >= ch.Cap())
-	assert.True(t, 15 >= ch.Len())
-
 	wg := sync.WaitGroup{}
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
 		ch.In() <- 15
 	}()
 
-	assert.True(t, 15 >= ch.Cap())
-	assert.True(t, 15 >= ch.Len())
-
 	for i := 0; i < 16; i++ {
 		v, ok := <-ch.Out()
 		assert.True(t, ok)
 		count += v.(int)
 	}
 
-	assert.True(t, 15 >= ch.Len())
-	assert.True(t, 10 >= ch.Cap())
-
 	wg.Wait()
 
 	assert.Equal(t, 165, count)
@@ -225,3 +216,51 @@ func testQuota2(t *testing.T) {
 	default:
 	}
 }
+
+func BenchmarkUnboundedChan_Fixed(b *testing.B) {
+	ch := NewUnboundedChanWithQuota(1000, 1000)
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			select {
+			case ch.In() <- 1:
+			}
+
+			<-ch.Out()
+		}
+	})
+
+	close(ch.In())
+}
+
+func BenchmarkUnboundedChan_Extension(b *testing.B) {
+	ch := NewUnboundedChanWithQuota(1000, 100000)
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			select {
+			case ch.In() <- 1:
+			}
+
+			<-ch.Out()
+		}
+	})
+
+	close(ch.In())
+}
+
+func BenchmarkUnboundedChan_ExtensionUnlimited(b *testing.B) {
+	ch := NewUnboundedChanWithQuota(1000, 0)
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			select {
+			case ch.In() <- 1:
+			}
+
+			<-ch.Out()
+		}
+	})
+
+	close(ch.In())
+}

log/logger.go

@@ -0,0 +1,30 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 gxlog
+
+type Logger interface {
+	Info(args ...interface{})
+	Warn(args ...interface{})
+	Error(args ...interface{})
+	Debug(args ...interface{})
+
+	Infof(fmt string, args ...interface{})
+	Warnf(fmt string, args ...interface{})
+	Errorf(fmt string, args ...interface{})
+	Debugf(fmt string, args ...interface{})
+}

sync/base_worker_pool.go

@@ -0,0 +1,188 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 gxsync
+
+import (
+	"fmt"
+	"runtime/debug"
+	"sync"
+)
+
+import (
+	"go.uber.org/atomic"
+)
+
+import (
+	gxlog "github.com/dubbogo/gost/log"
+)
+
+type WorkerPoolConfig struct {
+	NumWorkers int
+	NumQueues  int
+	QueueSize  int
+	Logger     gxlog.Logger
+}
+
+// baseWorkerPool is a worker pool with multiple queues.
+//
+// The below picture shows baseWorkerPool architecture.
+// Note that:
+// - TaskQueueX is a channel with buffer, please refer to taskQueues.
+// - Workers consume tasks in the dispatched queue only, please refer to dispatch(numWorkers).
+// - taskId will be incremented by 1 after a task is enqueued.
+// ┌───────┐  ┌───────┐  ┌───────┐                 ┌─────────────────────────┐
+// │worker0│  │worker2│  │worker4│               ┌─┤ taskId % NumQueues == 0 │
+// └───────┘  └───────┘  └───────┘               │ └─────────────────────────┘
+//     │          │          │                   │
+//     └───────consume───────┘                enqueue
+//                ▼                             task    ╔══════════════════╗
+//              ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┐  │      ║ baseWorkerPool:  ║
+//  TaskQueue0  │t0│t1│t2│t3│t4│t5│t6│t7│t8│t9│◀─┘      ║                  ║
+//              ├──┼──┼──┼──┼──┼──┼──┼──┼──┼──┤         ║ *NumWorkers=6    ║
+//  TaskQueue1  │t0│t1│t2│t3│t4│t5│t6│t7│t8│t9│◀┐       ║ *NumQueues=2     ║
+//              └──┴──┴──┴──┴──┴──┴──┴──┴──┴──┘ │       ║ *QueueSize=10    ║
+//                ▲                          enqueue    ╚══════════════════╝
+//     ┌───────consume───────┐                 task
+//     │          │          │                  │
+// ┌───────┐  ┌───────┐  ┌───────┐              │  ┌─────────────────────────┐
+// │worker1│  │worker3│  │worker5│              └──│ taskId % NumQueues == 1 │
+// └───────┘  └───────┘  └───────┘                 └─────────────────────────┘
+type baseWorkerPool struct {
+	logger gxlog.Logger
+
+	taskId     uint32
+	taskQueues []chan task
+
+	numWorkers *atomic.Int32
+
+	wg *sync.WaitGroup
+}
+
+func newBaseWorkerPool(config WorkerPoolConfig) *baseWorkerPool {
+	if config.NumWorkers < 1 {
+		config.NumWorkers = 1
+	}
+	if config.NumQueues < 1 {
+		config.NumQueues = 1
+	}
+	if config.QueueSize < 0 {
+		config.QueueSize = 0
+	}
+
+	taskQueues := make([]chan task, config.NumQueues)
+	for i := range taskQueues {
+		taskQueues[i] = make(chan task, config.QueueSize)
+	}
+
+	p := &baseWorkerPool{
+		logger:     config.Logger,
+		taskQueues: taskQueues,
+		numWorkers: new(atomic.Int32),
+		wg:         new(sync.WaitGroup),
+	}
+
+	initWg := new(sync.WaitGroup)
+	initWg.Add(config.NumWorkers)
+
+	p.dispatch(config.NumWorkers, initWg)
+
+	initWg.Wait()
+
+	return p
+}
+
+func (p *baseWorkerPool) dispatch(numWorkers int, wg *sync.WaitGroup) {
+	for i := 0; i < numWorkers; i++ {
+		p.newWorker(i, wg)
+	}
+}
+
+func (p *baseWorkerPool) Submit(t task) error {
+	panic("implement me")
+}
+
+func (p *baseWorkerPool) SubmitSync(t task) error {
+	panic("implement me")
+}
+
+func (p *baseWorkerPool) Close() {
+	if p.IsClosed() {
+		return
+	}
+
+	for _, q := range p.taskQueues {
+		close(q)
+	}
+	p.wg.Wait()
+}
+
+func (p *baseWorkerPool) IsClosed() bool {
+	return p.NumWorkers() == 0
+}
+
+func (p *baseWorkerPool) NumWorkers() int32 {
+	return p.numWorkers.Load()
+}
+
+func (p *baseWorkerPool) newWorker(workerId int, wg *sync.WaitGroup) {
+	p.wg.Add(1)
+	p.numWorkers.Add(1)
+	go p.worker(workerId, wg)
+}
+
+func (p *baseWorkerPool) worker(workerId int, wg *sync.WaitGroup) {
+	defer func() {
+		if n := p.numWorkers.Add(-1); n < 0 {
+			panic(fmt.Sprintf("numWorkers should be greater or equal to 0, but the value is %d", n))
+		}
+		p.wg.Done()
+	}()
+
+	if p.logger != nil {
+		p.logger.Infof("worker #%d is started\n", workerId)
+	}
+
+	chanId := workerId % len(p.taskQueues)
+
+	wg.Done()
+	for {
+		select {
+		case t, ok := <-p.taskQueues[chanId]:
+			if !ok {
+				if p.logger != nil {
+					p.logger.Infof("worker #%d is closed\n", workerId)
+				}
+				return
+			}
+			if t != nil {
+				func() {
+					// prevent from goroutine panic
+					defer func() {
+						if r := recover(); r != nil {
+							if p.logger != nil {
+								p.logger.Errorf("goroutine panic: %v\n%s\n", r, string(debug.Stack()))
+							}
+						}
+					}()
+					// execute task
+					t()
+				}()
+			}
+		}
+	}
+}

sync/connection_pool.go

@@ -0,0 +1,82 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 gxsync
+
+import (
+	"math/rand"
+	"sync/atomic"
+)
+
+import (
+	perrors "github.com/pkg/errors"
+)
+
+var (
+	PoolBusyErr = perrors.New("pool is busy")
+)
+
+func NewConnectionPool(config WorkerPoolConfig) WorkerPool {
+	return &ConnectionPool{
+		baseWorkerPool: newBaseWorkerPool(config),
+	}
+}
+
+type ConnectionPool struct {
+	*baseWorkerPool
+}
+
+func (p *ConnectionPool) Submit(t task) error {
+	if t == nil {
+		return perrors.New("task shouldn't be nil")
+	}
+
+	// put the task to a queue using Round Robin algorithm
+	taskId := atomic.AddUint32(&p.taskId, 1)
+	select {
+	case p.taskQueues[int(taskId)%len(p.taskQueues)] <- t:
+		return nil
+	default:
+	}
+
+	// put the task to a random queue with a maximum of len(p.taskQueues)/2 attempts
+	for i := 0; i < len(p.taskQueues)/2; i++ {
+		select {
+		case p.taskQueues[rand.Intn(len(p.taskQueues))] <- t:
+			return nil
+		default:
+			continue
+		}
+	}
+
+	return PoolBusyErr
+}
+
+func (p *ConnectionPool) SubmitSync(t task) error {
+	done := make(chan struct{})
+	fn := func() {
+		defer close(done)
+		t()
+	}
+
+	if err := p.Submit(fn); err != nil {
+		return err
+	}
+
+	<-done
+	return nil
+}