CommonRails: add process registry and on-exit listeners; register TelnetInstaller process for monitoring\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: mearvk

source/commons/CommonRails.java

@@ -6,6 +6,8 @@
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
+import java.util.Collections;
 
 public class CommonRails
 {
@@ -124,6 +126,70 @@ public static Boolean isSocketClosed(Socket socket)
         }
     }
 
+    // Registry for started Processes so CommonRails can monitor them and print on exit
+    protected static final List<Process> REGISTERED_PROCESSES = Collections.synchronizedList(new ArrayList<Process>());
+
+    /**
+     * Register a started Process with CommonRails. CommonRails will attach a listener
+     * to the process' onExit CompletableFuture (Java 9+) and print when the process exits.
+     * If onExit is unavailable/throws, a watcher thread using waitFor is started as a fallback.
+     */
+    public static synchronized void registerProcess(ProcessBuilder pb, Process process, Object owner)
+    {
+        if (process == null) return;
+
+        REGISTERED_PROCESSES.add(process);
+
+        Object printer = (owner == null) ? CommonRails.class : owner;
+
+        try
+        {
+            CommonRails.printSystemComponent(printer, process.hashCode(), ". CommonRails::registerProcess >> registered process: " + process);
+
+            // Attach onExit listener
+            process.onExit().thenAccept(p -> {
+                try
+                {
+                    CommonRails.printSystemComponent(printer, p.hashCode(), ". CommonRails::processExited >> process closed: " + p + " exit=" + p.exitValue());
+                }
+                catch (Throwable t)
+                {
+                    // Best-effort printing
+                    CommonRails.printSystemComponent(printer, p.hashCode(), ". CommonRails::processExited >> process closed: " + p);
+                }
+                finally
+                {
+                    REGISTERED_PROCESSES.remove(p);
+                }
+            });
+        }
+        catch (Throwable t)
+        {
+            // Fallback: spawn a watcher thread that waits for the process
+            new Thread(() -> {
+                try
+                {
+                    int rv = process.waitFor();
+
+                    CommonRails.printSystemComponent(printer, process.hashCode(), ". CommonRails::processExited(watcher) >> process closed: " + process + " exit=" + rv);
+                }
+                catch (Exception e)
+                {
+                    e.printStackTrace(System.err);
+                }
+                finally
+                {
+                    REGISTERED_PROCESSES.remove(process);
+                }
+            }, "CommonRails-ProcessWatcher-" + process.hashCode()).start();
+        }
+    }
+
+    public static synchronized List<Process> getRegisteredProcesses()
+    {
+        return new ArrayList<>(REGISTERED_PROCESSES);
+    }
+
     public static class TelnetCallOnComplete implements Runnable
     {
         protected WebExpress web_express;

source/telnet/TelnetInstaller.java

@@ -35,6 +35,13 @@ public TelnetInstaller(WebExpress web_express)
 
             this.process = process_builder.start();
 
+            // register process with CommonRails so it can monitor exit/finish events
+            try {
+                CommonRails.registerProcess(this.process_builder, this.process, this);
+            } catch (Exception ignore) {
+                // best-effort: don't let registration prevent initialization
+            }
+
             this.reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
 
             this.writer = new BufferedWriter(new OutputStreamWriter(process.getOutputStream()));