fix: stabilize federated agent runtime updates (#550)

go-gost/x/config/config_concurrency_test.go

@@ -0,0 +1,121 @@
+package config
+
+import (
+	"encoding/json"
+	"path/filepath"
+	"sync"
+	"testing"
+)
+
+func TestGlobalReturnsDetachedSnapshot(t *testing.T) {
+	original := Global()
+	t.Cleanup(func() { Set(original) })
+
+	Set(&Config{Services: []*ServiceConfig{{
+		Name:     "snapshot-service",
+		Metadata: map[string]any{"paused": false},
+		Handler: &HandlerConfig{
+			Type:     "relay",
+			Metadata: map[string]any{"retries": 2},
+		},
+	}}})
+
+	snapshot := Global()
+	snapshot.Services[0].Name = "changed"
+	snapshot.Services[0].Metadata["paused"] = true
+	snapshot.Services[0].Handler.Metadata["retries"] = 9
+
+	current := Global()
+	if current.Services[0].Name != "snapshot-service" {
+		t.Fatalf("snapshot mutated global service name: %q", current.Services[0].Name)
+	}
+	if paused, _ := current.Services[0].Metadata["paused"].(bool); paused {
+		t.Fatalf("snapshot mutated global service metadata")
+	}
+	if retries, _ := current.Services[0].Handler.Metadata["retries"].(int); retries != 2 {
+		t.Fatalf("snapshot mutated nested handler metadata: %v", current.Services[0].Handler.Metadata["retries"])
+	}
+}
+
+func TestConcurrentGlobalSnapshotAndUpdate(t *testing.T) {
+	original := Global()
+	t.Cleanup(func() { Set(original) })
+
+	Set(&Config{Services: []*ServiceConfig{{
+		Name:     "concurrent-service",
+		Metadata: map[string]any{"generation": 0},
+	}}})
+
+	var wg sync.WaitGroup
+	for worker := 0; worker < 4; worker++ {
+		wg.Add(1)
+		go func(worker int) {
+			defer wg.Done()
+			for i := 0; i < 500; i++ {
+				if err := OnUpdate(func(c *Config) error {
+					c.Services[0] = &ServiceConfig{
+						Name:     "concurrent-service",
+						Metadata: map[string]any{"generation": worker*500 + i},
+					}
+					return nil
+				}); err != nil {
+					t.Errorf("OnUpdate: %v", err)
+					return
+				}
+			}
+		}(worker)
+	}
+
+	for i := 0; i < 2000; i++ {
+		if _, err := json.Marshal(Global()); err != nil {
+			t.Fatalf("marshal snapshot: %v", err)
+		}
+	}
+	wg.Wait()
+}
+
+func TestConcurrentPersistProducesValidConfig(t *testing.T) {
+	original := Global()
+	originalPath := PersistPath()
+	persistMu.Lock()
+	originalEnabled := persistEnable
+	persistMu.Unlock()
+	t.Cleanup(func() {
+		Set(original)
+		SetPersistPath(originalPath)
+		persistMu.Lock()
+		persistEnable = originalEnabled
+		persistMu.Unlock()
+	})
+
+	path := filepath.Join(t.TempDir(), "gost.json")
+	SetPersistPath(path)
+	EnablePersist()
+	Set(&Config{Services: []*ServiceConfig{{Name: "persist-service"}}})
+
+	var wg sync.WaitGroup
+	for worker := 0; worker < 4; worker++ {
+		wg.Add(1)
+		go func(worker int) {
+			defer wg.Done()
+			for i := 0; i < 50; i++ {
+				if err := OnUpdate(func(c *Config) error {
+					c.Services[0].Metadata = map[string]any{"generation": worker*50 + i}
+					return nil
+				}); err != nil {
+					t.Errorf("persist update: %v", err)
+					return
+				}
+			}
+		}(worker)
+	}
+	wg.Wait()
+
+	var persisted Config
+	if err := persisted.ReadFile(path); err != nil {
+		t.Fatalf("read persisted config: %v", err)
+	}
+	if len(persisted.Services) != 1 || persisted.Services[0] == nil || persisted.Services[0].Name != "persist-service" {
+		t.Fatalf("unexpected persisted services: %#v", persisted.Services)
+	}
+}