Refactor process termination logic: introduce ProcessUtil utility for reusable and cleaner code.

Author: flemming-n-larsen

gui-app/src/main/kotlin/dev/robocode/tankroyale/gui/booter/BootProcess.kt

@@ -8,6 +8,7 @@ import dev.robocode.tankroyale.gui.ui.console.BooterErrorConsole
 import dev.robocode.tankroyale.gui.util.EDT
 import dev.robocode.tankroyale.gui.util.FileUtil
 import dev.robocode.tankroyale.gui.util.ResourceUtil
+import dev.robocode.tankroyale.gui.util.ProcessUtil
 import java.io.BufferedReader
 import java.io.FileNotFoundException
 import java.io.InputStreamReader
@@ -155,14 +156,7 @@ object BootProcess {
     }
 
     private fun stopProcess() {
-        booterProcess?.apply {
-            if (isAlive) {
-                PrintStream(outputStream).apply {
-                    println("quit")
-                    flush()
-                }
-            }
-        }
+        ProcessUtil.stopProcess(booterProcess, "quit", false)
         booterProcess = null
     }
 

gui-app/src/main/kotlin/dev/robocode/tankroyale/gui/server/ServerProcess.kt

@@ -8,10 +8,10 @@ import dev.robocode.tankroyale.gui.ui.server.ServerLogFrame
 import dev.robocode.tankroyale.gui.util.EDT
 import dev.robocode.tankroyale.gui.util.FileUtil
 import dev.robocode.tankroyale.gui.util.ResourceUtil
+import dev.robocode.tankroyale.gui.util.ProcessUtil
 import java.io.BufferedReader
 import java.io.FileNotFoundException
 import java.io.InputStreamReader
-import java.io.PrintStream
 import java.nio.file.Files
 import java.nio.file.Paths
 import java.util.concurrent.atomic.AtomicBoolean
@@ -26,7 +26,7 @@ object ServerProcess {
     private val logThreadRunning = AtomicBoolean(false)
 
     init {
-        ServerActions
+        ServerActions // trigger initialization of ServerEvents. Is not "unused"
     }
 
     fun isRunning(): Boolean {
@@ -71,15 +71,7 @@ object ServerProcess {
         stopLogThread()
 
         val process = processRef.get()
-        process?.apply {
-            if (isAlive) {
-                PrintStream(outputStream).apply {
-                    println("q")
-                    flush()
-                }
-            }
-            waitFor()
-        }
+        ProcessUtil.stopProcess(process, "q", true)
         processRef.set(null)
         logThread = null
 

gui-app/src/main/kotlin/dev/robocode/tankroyale/gui/util/ProcessUtil.kt

@@ -0,0 +1,69 @@
+package dev.robocode.tankroyale.gui.util
+
+import java.io.PrintStream
+import java.util.concurrent.TimeUnit
+import java.util.logging.Level
+import java.util.logging.Logger
+
+object ProcessUtil {
+    private val logger = Logger.getLogger(ProcessUtil::class.java.name)
+
+    /**
+     * Sends a quit command to the given process and optionally waits for it to exit.
+     *
+     * @param process The process to stop.
+     * @param quitCommand The command string to send to the process' standard input to request shutdown.
+     * @param waitForExit If true, waits for the process to terminate after sending the command.
+     * @param forceTerminate If true, forcibly terminates the process if it doesn't exit within the timeout.
+     * @return True, if the process was successfully stopped, false otherwise.
+     */
+    @JvmStatic
+    @JvmOverloads
+    fun stopProcess(
+        process: Process?, 
+        quitCommand: String, 
+        waitForExit: Boolean = false,
+        forceTerminate: Boolean = false
+    ): Boolean {
+        if (process == null || !process.isAlive) {
+            return true // Nothing to do, a process is already stopped
+        }
+
+        // Send quit command
+        var quitCommandSent = false
+        try {
+            PrintStream(process.outputStream).use { ps ->
+                ps.println(quitCommand)
+                ps.flush()
+                quitCommandSent = true
+            }
+        } catch (e: Exception) {
+            logger.log(Level.WARNING, "Failed to send quit command to process", e)
+        }
+
+        // If we don't need to wait, return whether the command was sent
+        if (!waitForExit) {
+            return quitCommandSent
+        }
+
+        // Wait for a process to exit
+        try {
+            val exited = process.waitFor(500, TimeUnit.MILLISECONDS)
+
+            // If a process didn't exit and force termination is requested
+            if (!exited && forceTerminate) {
+                process.destroyForcibly()
+                return process.waitFor(1000, TimeUnit.MILLISECONDS) // Give it 3 more seconds to terminate
+            }
+            return exited
+
+        } catch (_: InterruptedException) {
+            Thread.currentThread().interrupt()
+            logger.log(Level.WARNING, "Thread interrupted while waiting for process to exit")
+        } catch (e: Exception) {
+            logger.log(Level.WARNING, "Failed while waiting for process to exit", e)
+        }
+
+        return !process.isAlive
+    }
+}