From be0b0eff2421ecf250e68201b2dbe01637631842 Mon Sep 17 00:00:00 2001
From: Emre Karabay <karabay@bu.edu>
Date: Fri, 27 Dec 2024 22:11:49 -0500
Subject: [PATCH] Improved process termination logic in process_unix.go

---
 utils/process_unix.go | 43 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 34 insertions(+), 9 deletions(-)

diff --git a/utils/process_unix.go b/utils/process_unix.go
index bf9a050..7c649a8 100644
--- a/utils/process_unix.go
+++ b/utils/process_unix.go
@@ -3,7 +3,10 @@
 
 package utils
 
+// Dummy test thing
+
 import (
+	"errors"
 	"fmt"
 	"os"
 	"syscall"
@@ -22,23 +25,45 @@ func IsProcessRunning(pid int) bool {
 	return err == nil
 }
 
-// StopProcess stops a process by its PID on Unix-based systems.
 func StopProcess(pid int) error {
-	process, err := os.FindProcess(pid)
-	if err != nil {
+	// Check if the process exists
+	if _, err := os.FindProcess(pid); err != nil {
 		return fmt.Errorf("could not find process: %w", err)
 	}
 
-	// Send SIGTERM (soft termination)
-	err = process.Signal(syscall.SIGTERM)
+	// Send SIGTERM to the process group
+	err := syscall.Kill(-pid, syscall.SIGTERM)
 	if err != nil {
-		return fmt.Errorf("could not terminate process: %w", err)
+		return fmt.Errorf("could not send SIGTERM to process: %w", err)
 	}
+	fmt.Printf("SIGTERM sent to process group %d\n", pid)
 
-	// termination might take some time and it will effect the next steps during update, sleep 5 seconds just in case
-	time.Sleep(5 * time.Second)
+	// Wait for graceful termination
+	timeout := time.After(10 * time.Second)
+	ticker := time.NewTicker(500 * time.Millisecond)
+	defer ticker.Stop()
 
-	return nil
+	for {
+		select {
+		case <-timeout:
+			// Escalate to SIGKILL if process does not terminate
+			err = syscall.Kill(-pid, syscall.SIGKILL)
+			if err != nil {
+				return fmt.Errorf("could not kill process: %w", err)
+			}
+			fmt.Printf("SIGKILL sent to process group %d\n", pid)
+			time.Sleep(1 * time.Second)
+			if IsProcessRunning(pid) {
+				return errors.New("process did not terminate even after SIGKILL")
+			}
+			return fmt.Errorf("process did not terminate gracefully; sent SIGKILL")
+		case <-ticker.C:
+			if !IsProcessRunning(pid) {
+				fmt.Printf("Process group %d terminated successfully\n", pid)
+				return nil
+			}
+		}
+	}
 }
 
 func SetFileDescriptorLimit(limit uint64) error {