fix race when recycling filterManager (#613)

Signed-off-by: spacewander <[email protected]>

Author: spacewander

api/pkg/filtermanager/filtermanager.go

@@ -43,7 +43,7 @@ type filterManager struct {
 	encodeIdx            int
 	rspHdr               api.ResponseHeaderMap
 
-	runningInGoThread atomic.Bool
+	runningInGoThread atomic.Int32
 	hdrLock           sync.Mutex // FIXME: remove this once we get request headers from the OnLog directly
 
 	// use a group of bools instead of map to avoid lookup
@@ -71,6 +71,8 @@ func (m *filterManager) Reset() {
 	m.encodeIdx = -1
 	m.rspHdr = nil
 
+	m.runningInGoThread.Store(0) // defence in depth
+
 	m.canSkipDecodeHeaders = false
 	m.canSkipDecodeData = false
 	m.canSkipEncodeHeaders = false
@@ -81,11 +83,15 @@ func (m *filterManager) Reset() {
 }
 
 func (m *filterManager) IsRunningInGoThread() bool {
-	return m.runningInGoThread.Load()
+	return m.runningInGoThread.Load() != 0
 }
 
 func (m *filterManager) MarkRunningInGoThread(flag bool) {
-	m.runningInGoThread.Store(flag)
+	if flag {
+		m.runningInGoThread.Add(1)
+	} else {
+		m.runningInGoThread.Add(-1)
+	}
 }
 
 func (m *filterManager) DebugModeEnabled() bool {

api/pkg/filtermanager/filtermanager_test.go

@@ -528,6 +528,7 @@ func (f *accessFieldOnLogFilter) OnLog(_ api.RequestHeaderMap, _ api.RequestTrai
 }
 
 func TestDoNotRecycleInUsedFilterManager(t *testing.T) {
+	envoy.DisableLogInTest() // otherwise, there is too much output
 	config := initFilterManagerConfig("ns")
 	config.parsed = []*model.ParsedFilterConfig{
 		{
@@ -536,7 +537,7 @@ func TestDoNotRecycleInUsedFilterManager(t *testing.T) {
 		},
 	}
 
-	n := 10
+	n := 100
 	var wg sync.WaitGroup
 
 	// DecodeHeaders