Deliver async reports from a goroutine pool

v2/async_runner.go

@@ -0,0 +1,74 @@
+package bugsnag
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+)
+
+type AsyncRunner[T any] struct {
+	ch        chan T
+	wg        sync.WaitGroup
+	processFn ProcessFunc[T]
+}
+
+type ProcessFunc[T any] func(T)
+
+var ErrChannelFull = errors.New("channel is full")
+
+func NewAsyncRunner[T any](
+	ctx context.Context,
+	channelSize int,
+	workerCount int,
+	processFn ProcessFunc[T],
+) (*AsyncRunner[T], error) {
+	if channelSize < 0 {
+		return nil, fmt.Errorf("channelSize must be non negative")
+	}
+
+	b := &AsyncRunner[T]{
+		ch:        make(chan T, channelSize),
+		wg:        sync.WaitGroup{},
+		processFn: processFn,
+	}
+
+	b.startWorkers(ctx, workerCount)
+	return b, nil
+}
+
+func (b *AsyncRunner[T]) Submit(v T) error {
+	select {
+	case b.ch <- v:
+		// success
+		return nil
+	default:
+		// channel is full
+		return ErrChannelFull
+	}
+}
+
+func (b *AsyncRunner[T]) Wait() {
+	b.wg.Wait()
+}
+
+func (b *AsyncRunner[T]) startWorkers(ctx context.Context, workerCount int) {
+	b.wg.Add(workerCount)
+	for i := 0; i < workerCount; i++ {
+		go func() {
+			defer b.wg.Done()
+			b.workerLoop(ctx)
+		}()
+	}
+}
+
+func (b *AsyncRunner[T]) workerLoop(ctx context.Context) {
+	for {
+		select {
+		case msg := <-b.ch:
+			b.processFn(msg)
+		case <-ctx.Done():
+			return
+		}
+	}
+}

v2/async_runner_test.go

@@ -0,0 +1,69 @@
+package bugsnag
+
+import (
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func TestAsyncRunner(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	channelSize := 10
+	workerCount := 5
+	var i atomic.Int32
+	processFn := func(val int) {
+		i.Add(1)
+	}
+
+	runner, err := NewAsyncRunner(ctx, channelSize, workerCount, processFn)
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	if cap(runner.ch) != channelSize {
+		t.Errorf("Expected channel size of %v, but got %v", channelSize, cap(runner.ch))
+	}
+
+	if runner.processFn == nil {
+		t.Error("Expected processFn to be set, but it was nil")
+	}
+
+	runner.Submit(1)
+	runner.Submit(2)
+	runner.Submit(3)
+	time.Sleep(100 * time.Millisecond)
+	cancel()
+	runner.Wait()
+
+	if i.Load() != 3 {
+		t.Errorf("Expected i to be 3, but got %v", i.Load())
+	}
+}
+
+func TestAsyncRunnerChannelFull(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	channelSize := 10
+	workerCount := 5
+	processFn := func(_ int) {
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	runner, err := NewAsyncRunner(ctx, channelSize, workerCount, processFn)
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	for i := 0; i < channelSize; i++ {
+		if err := runner.Submit(i); err != nil {
+			t.Errorf("Unexpected error: %v", err)
+		}
+	}
+
+	if err := runner.Submit(10); err != ErrChannelFull {
+		t.Errorf("Expected channel full error, but got %v", err)
+	}
+
+	cancel()
+	runner.Wait()
+}

v2/bugsnag.go

@@ -39,6 +39,8 @@ var DefaultSessionPublishInterval = 60 * time.Second
 var defaultNotifier = Notifier{&Config, nil}
 var sessionTracker sessions.SessionTracker
 
+var asyncRunner *AsyncRunner[*payload]
+
 // Configure Bugsnag. The only required setting is the APIKey, which can be
 // obtained by clicking on "Settings" in your Bugsnag dashboard. This function
 // is also responsible for installing the global panic handler, so it should be
@@ -51,6 +53,7 @@ func Configure(config Configuration) {
 	// Only do once in case the user overrides the default panichandler, and
 	// configures multiple times.
 	panicHandlerOnce.Do(Config.PanicHandler)
+	setupAsyncRunner()
 }
 
 // StartSession creates new context from the context.Context instance with
@@ -253,6 +256,8 @@ func init() {
 		Logger:              log.New(os.Stdout, log.Prefix(), log.Flags()),
 		PanicHandler:        defaultPanicHandler,
 		Transport:           http.DefaultTransport,
+		NumGoroutines:       10,
+		MaxPendingReports:   1000,
 
 		flushSessionsOnRepanic: true,
 	})
@@ -282,3 +287,20 @@ func updateSessionConfig() {
 		Logger:              Config.Logger,
 	})
 }
+
+func setupAsyncRunner() {
+	var err error
+	asyncRunner, err = NewAsyncRunner[*payload](
+		context.Background(),
+		Config.MaxPendingReports,
+		Config.NumGoroutines,
+		func(p *payload) {
+			if err := publisher.publishReport(p); err != nil {
+				p.logf("bugsnag/defaultReportPublisher.publishReport: %v", err)
+			}
+		},
+	)
+	if err != nil {
+		panic(err)
+	}
+}

v2/configuration.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
 )
 
@@ -98,9 +99,19 @@ type Configuration struct {
 	// can be configured if you are in an environment
 	// that has stringent conditions on making http requests.
 	Transport http.RoundTripper
+
 	// Whether bugsnag should notify synchronously. This defaults to false which
 	// causes bugsnag-go to spawn a new goroutine for each notification.
 	Synchronous bool
+
+	// Number of goroutines to use for sending notifications in asynchronous
+	// mode. This defaults to 10.
+	NumGoroutines int
+
+	// The maximum number of reports that can be pending in asynchronous mode.
+	// This defaults to 1000.
+	MaxPendingReports int
+
 	// Whether the notifier should send all sessions recorded so far to Bugsnag
 	// when repanicking to ensure that no session information is lost in a
 	// fatal crash.
@@ -307,6 +318,18 @@ func (config *Configuration) loadEnv() {
 	if synchronous := os.Getenv("BUGSNAG_SYNCHRONOUS"); synchronous != "" {
 		envConfig.Synchronous = synchronous == "1"
 	}
+	if numGoroutines := os.Getenv("BUGSNAG_NUM_GOROUTINES"); numGoroutines != "" {
+		num, err := strconv.Atoi(numGoroutines)
+		if err != nil {
+			envConfig.NumGoroutines = num
+		}
+	}
+	if maxPendingReports := os.Getenv("BUGSNAG_MAX_PENDING_REPORTS"); maxPendingReports != "" {
+		max, err := strconv.Atoi(maxPendingReports)
+		if err != nil {
+			envConfig.MaxPendingReports = max
+		}
+	}
 	if disablePanics := os.Getenv("BUGSNAG_DISABLE_PANIC_HANDLER"); disablePanics == "1" {
 		envConfig.PanicHandler = func() {}
 	}

v2/go.mod

@@ -1,11 +1,12 @@
 module github.com/bugsnag/bugsnag-go/v2
 
-go 1.15
+go 1.18
 
 require (
 	github.com/bitly/go-simplejson v0.5.1
 	github.com/bugsnag/panicwrap v1.3.4
 	github.com/google/uuid v1.6.0
-	github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 // indirect
 	github.com/pkg/errors v0.9.1
 )
+
+require github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 // indirect

v2/report_publisher.go

@@ -17,11 +17,5 @@ func (*defaultReportPublisher) publishReport(p *payload) error {
 		return p.deliver()
 	}
 
-	go func(p *payload) {
-		if err := p.deliver(); err != nil {
-			// Ensure that any errors are logged if they occur in a goroutine.
-			p.logf("bugsnag/defaultReportPublisher.publishReport: %v", err)
-		}
-	}(p)
-	return nil
+	return asyncRunner.Submit(p)
 }