From de95ec6606b40d16646e0587648e35deee37431e Mon Sep 17 00:00:00 2001
From: nxtcoder17 <nxtcoder17@gmail.com>
Date: Mon, 23 Sep 2024 18:34:45 +0530
Subject: [PATCH] feat: improves executor and signal handling

---
 main.go                |  2 +-
 pkg/executor/exec.go   | 33 +++++++++++++++++++++++----------
 pkg/watcher/watcher.go |  2 +-
 3 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/main.go b/main.go
index c491fe0..65c14c1 100644
--- a/main.go
+++ b/main.go
@@ -113,7 +113,7 @@ func main() {
 				execArgs = cctx.Args().Tail()
 			}
 
-			ex := executor.NewExecutor(ctx, executor.ExecutorArgs{
+			ex := executor.NewExecutor(executor.ExecutorArgs{
 				Logger: logger,
 				Command: func(context.Context) *exec.Cmd {
 					cmd := exec.Command(execCmd, execArgs...)
diff --git a/pkg/executor/exec.go b/pkg/executor/exec.go
index 6ffae6b..95eac52 100644
--- a/pkg/executor/exec.go
+++ b/pkg/executor/exec.go
@@ -12,9 +12,9 @@ import (
 )
 
 type Executor struct {
-	ctx    context.Context
-	done   chan os.Signal
-	logger *slog.Logger
+	done      chan os.Signal
+	logger    *slog.Logger
+	isRunning bool
 
 	newCmd func(context.Context) *exec.Cmd
 	mu     sync.Mutex
@@ -25,7 +25,7 @@ type ExecutorArgs struct {
 	Command func(context.Context) *exec.Cmd
 }
 
-func NewExecutor(ctx context.Context, args ExecutorArgs) *Executor {
+func NewExecutor(args ExecutorArgs) *Executor {
 	done := make(chan os.Signal, 1)
 	signal.Notify(done, syscall.SIGTERM)
 
@@ -36,19 +36,24 @@ func NewExecutor(ctx context.Context, args ExecutorArgs) *Executor {
 	return &Executor{
 		done:   done,
 		logger: args.Logger,
-		ctx:    ctx,
 		newCmd: args.Command,
 		mu:     sync.Mutex{},
 	}
 }
 
 func (ex *Executor) Exec() error {
+	ex.logger.Debug("[exec:pre] starting process")
 	ex.mu.Lock()
-	defer ex.mu.Unlock()
+	ex.isRunning = true
+
+	defer func() {
+		ex.isRunning = false
+		ex.mu.Unlock()
+	}()
 
 	ex.logger.Debug("[exec] starting process")
 
-	ctx, cf := context.WithCancel(ex.ctx)
+	ctx, cf := context.WithCancel(context.TODO())
 	defer cf()
 
 	cmd := ex.newCmd(ctx)
@@ -65,9 +70,15 @@ func (ex *Executor) Exec() error {
 		case <-ex.done:
 			ex.logger.Debug("executor terminated", "pid", cmd.Process.Pid)
 		}
+		for len(ex.done) > 0 {
+			<-ex.done
+		}
+
 		ex.logger.Debug("[exec] killing process", "pid", cmd.Process.Pid)
 		if err := syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL); err != nil {
-			ex.logger.Error("failed to kill process", "pid", cmd.Process.Pid, "err", err)
+			if err.Error() != "no such process" {
+				ex.logger.Error("failed to kill process", "pid", cmd.Process.Pid, "err", err)
+			}
 		}
 	}()
 
@@ -75,12 +86,14 @@ func (ex *Executor) Exec() error {
 		if strings.HasPrefix(err.Error(), "signal:") {
 			ex.logger.Debug("wait terminated, received", "signal", err.Error())
 		}
-		return err
+		ex.logger.Debug("while waiting, got", "err", err)
 	}
 
 	return nil
 }
 
 func (ex *Executor) Kill() {
-	ex.done <- os.Signal(syscall.SIGTERM)
+	if ex.isRunning {
+		ex.done <- os.Signal(syscall.SIGTERM)
+	}
 }
diff --git a/pkg/watcher/watcher.go b/pkg/watcher/watcher.go
index cae3022..0fc537e 100644
--- a/pkg/watcher/watcher.go
+++ b/pkg/watcher/watcher.go
@@ -92,7 +92,7 @@ func (f *fsnWatcher) WatchEvents(watcherFunc func(event Event, fp string) error)
 				eInfo.Counter += 1
 				f.eventMap[event.Name] = eInfo
 
-				if time.Since(eInfo.Time) < 1*time.Second {
+				if time.Since(eInfo.Time) < 100*time.Millisecond {
 					f.Logger.Debug("too many events under 1s, ignoring...", "counter", eInfo.Counter)
 					continue
 				}