From 2a150d6aa190a4be0d1fc4f4b8e16056fc81d666 Mon Sep 17 00:00:00 2001
From: Angelo Marletta <angelo.marletta@coinbase.com>
Date: Wed, 8 May 2024 20:23:00 -0700
Subject: [PATCH] Deliver async reports from a goroutine pool

---
 v2/bugsnag.go          | 10 ++++++++++
 v2/configuration.go    | 23 +++++++++++++++++++++++
 v2/go.mod              |  1 +
 v2/go.sum              |  2 ++
 v2/report_publisher.go |  6 ++++--
 5 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/v2/bugsnag.go b/v2/bugsnag.go
index 631d2e93..45575309 100644
--- a/v2/bugsnag.go
+++ b/v2/bugsnag.go
@@ -11,6 +11,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/alitto/pond"
 	"github.com/bugsnag/bugsnag-go/v2/device"
 	"github.com/bugsnag/bugsnag-go/v2/errors"
 	"github.com/bugsnag/bugsnag-go/v2/sessions"
@@ -39,6 +40,8 @@ var DefaultSessionPublishInterval = 60 * time.Second
 var defaultNotifier = Notifier{&Config, nil}
 var sessionTracker sessions.SessionTracker
 
+var asyncPool *pond.WorkerPool
+
 // 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 +54,7 @@ func Configure(config Configuration) {
 	// Only do once in case the user overrides the default panichandler, and
 	// configures multiple times.
 	panicHandlerOnce.Do(Config.PanicHandler)
+	setupAsyncPool()
 }
 
 // StartSession creates new context from the context.Context instance with
@@ -253,6 +257,8 @@ func init() {
 		Logger:              log.New(os.Stdout, log.Prefix(), log.Flags()),
 		PanicHandler:        defaultPanicHandler,
 		Transport:           http.DefaultTransport,
+		NumGoroutines:       10,
+		MaxPendingReports:   1000,
 
 		flushSessionsOnRepanic: true,
 	})
@@ -282,3 +288,7 @@ func updateSessionConfig() {
 		Logger:              Config.Logger,
 	})
 }
+
+func setupAsyncPool() {
+	asyncPool = pond.New(Config.NumGoroutines, Config.MaxPendingReports)
+}
diff --git a/v2/configuration.go b/v2/configuration.go
index 48680bb3..59c0ce30 100644
--- a/v2/configuration.go
+++ b/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() {}
 	}
diff --git a/v2/go.mod b/v2/go.mod
index d891c127..412d1d65 100644
--- a/v2/go.mod
+++ b/v2/go.mod
@@ -3,6 +3,7 @@ module github.com/bugsnag/bugsnag-go/v2
 go 1.15
 
 require (
+	github.com/alitto/pond v1.8.3
 	github.com/bitly/go-simplejson v0.5.1
 	github.com/bugsnag/panicwrap v1.3.4
 	github.com/google/uuid v1.6.0
diff --git a/v2/go.sum b/v2/go.sum
index 83d02484..3556764e 100644
--- a/v2/go.sum
+++ b/v2/go.sum
@@ -1,3 +1,5 @@
+github.com/alitto/pond v1.8.3 h1:ydIqygCLVPqIX/USe5EaV/aSRXTRXDEI9JwuDdu+/xs=
+github.com/alitto/pond v1.8.3/go.mod h1:CmvIIGd5jKLasGI3D87qDkQxjzChdKMmnXMg3fG6M6Q=
 github.com/bitly/go-simplejson v0.5.1 h1:xgwPbetQScXt1gh9BmoJ6j9JMr3TElvuIyjR8pgdoow=
 github.com/bitly/go-simplejson v0.5.1/go.mod h1:YOPVLzCfwK14b4Sff3oP1AmGhI9T9Vsg84etUnlyp+Q=
 github.com/bugsnag/panicwrap v1.3.4 h1:A6sXFtDGsgU/4BLf5JT0o5uYg3EeKgGx3Sfs+/uk3pU=
diff --git a/v2/report_publisher.go b/v2/report_publisher.go
index 87d228fc..a4d0e53c 100644
--- a/v2/report_publisher.go
+++ b/v2/report_publisher.go
@@ -17,11 +17,13 @@ func (*defaultReportPublisher) publishReport(p *payload) error {
 		return p.deliver()
 	}
 
-	go func(p *payload) {
+	if !asyncPool.TrySubmit(func() {
 		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 fmt.Errorf("failed to submit report to async pool")
+	}
 	return nil
 }