fix loading of json config

main/config_json.go

@@ -1,23 +1,35 @@
 package main
 
 import (
+	"context"
 	"io"
 	"os"
 	"os/exec"
 
 	"v2ray.com/core"
+	"v2ray.com/core/common"
 	"v2ray.com/core/common/platform"
+	"v2ray.com/core/common/signal"
 )
 
+type logWriter struct{}
+
+func (*logWriter) Write(b []byte) (int, error) {
+	n, err := os.Stderr.Write(b)
+	if err == nil {
+		os.Stderr.WriteString(platform.LineSeparator())
+	}
+	return n, err
+}
+
 func jsonToProto(input io.Reader) (*core.Config, error) {
 	v2ctl := platform.GetToolLocation("v2ctl")
-	_, err := os.Stat(v2ctl)
+	if _, err := os.Stat(v2ctl); err != nil {
-	if err != nil {
 		return nil, err
 	}
 	cmd := exec.Command(v2ctl, "config")
 	cmd.Stdin = input
-	cmd.Stderr = os.Stderr
+	cmd.Stderr = &logWriter{}
 	cmd.SysProcAttr = getSysProcAttr()
 
 	stdoutReader, err := cmd.StdoutPipe()
@@ -30,19 +42,34 @@ func jsonToProto(input io.Reader) (*core.Config, error) {
 		return nil, err
 	}
 
-	config, err := core.LoadConfig(core.ConfigFormat_Protobuf, stdoutReader)
+	var config *core.Config
 
-	cmd.Wait()
+	loadTask := signal.ExecuteAsync(func() error {
+		c, err := core.LoadConfig(core.ConfigFormat_Protobuf, stdoutReader)
+		if err != nil {
+			return err
+		}
+		config = c
+		return nil
+	})
 
-	return config, err
+	waitTask := signal.ExecuteAsync(func() error {
+		return cmd.Wait()
+	})
+
+	if err := signal.ErrorOrFinish2(context.Background(), loadTask, waitTask); err != nil {
+		return nil, err
+	}
+
+	return config, nil
 }
 
 func init() {
-	core.RegisterConfigLoader(core.ConfigFormat_JSON, func(input io.Reader) (*core.Config, error) {
+	common.Must(core.RegisterConfigLoader(core.ConfigFormat_JSON, func(input io.Reader) (*core.Config, error) {
 		config, err := jsonToProto(input)
 		if err != nil {
 			return nil, newError("failed to execute v2ctl to convert config file.").Base(err).AtWarning()
 		}
 		return config, nil
-	})
+	}))
 }