created mirror

2026-09-14 20:19:29 -04:00
commit 6764738d92
600 changed files with 87187 additions and 0 deletions
--- a/Java/SafeExit.java
+++ b/Java/SafeExit.java
@@ -0,0 +1,95 @@
+/*   
+SafeExit.java
+ *    
+ *    You may use and distribute under the terms of either the GNU Lesser
+ *    General Public License, either version 2 of the license or,
+ *    at your choice, any later version. Alternatively, you may use and
+ *    distribute under the terms of the XPL.
+ *
+ *    See the LICENSE.lgpl and LICENSE.xpl files for the specific terms of 
+ *    the licenses.
+ *
+ *    This software is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the README
+ *    file for more details.
+ *
+ */
+/*
+ * Written by Antti-Juhani Kaijanaho.
+ */
+
+package org.gzigzag;
+
+import java.util.*;
+
+/** A class that can be told of things that need to be done at
+    shutdown and that will do them when it is asked to kill the
+    program. Since Java does not provide pre-shutdown hooks, we need
+    to provide them ourselves.  */
+public class SafeExit {
+
+    /** An object that wants to be called at exit time for cleanup.
+     */
+    public interface Cleanupable {
+	/** Perform any cleanup operations necessary for this object.
+	 */
+        void cleanup() throws Throwable;
+    }
+
+    private static Vector things_to_clean_up = new Vector();
+
+    public static void registerObject(Cleanupable o) {
+        things_to_clean_up.addElement(o);
+    }
+
+    public static void unregisterObject(Cleanupable o) {
+        things_to_clean_up.removeElement(o);
+    }
+
+    /** This is a safe exit procedure that kills all threads first,
+        then cleans up those things that are registered for cleanup
+        and then exits. */
+    public static void exit(int exitcode) {
+        // The following is from "The Java Programming Language",
+        // Second Edition, p. 329--330
+
+        // this needs the threads to be modified so that they end on
+        // interrupt or something, so now this is disabled
+//          Thread myThread = Thread.currentThread();
+//          ThreadGroup thisGroup = myThread.getThreadGroup();
+//          int count = thisGroup.activeCount();
+//          Thread[] threads = new Thread[count + 20];
+//          thisGroup.enumerate(threads);
+
+//          for (int i = 0; i < threads.length; i++) {
+//              if (threads[i] != null && threads[i] != myThread) {
+//                  threads[i].interrupt();
+//              }
+//          }
+
+//          for (int i = 0; i < threads.length; i++) {
+//              if (threads[i] != null && threads[i] != myThread) {
+//                  try {
+//                      threads[i].join();
+//                  } catch (InterruptedException e) {
+//                      // ignore
+//                  }
+//              }
+//          }
+
+        //  Ok, now to our own stuff: clean up
+        for (Enumeration e = things_to_clean_up.elements();
+             e.hasMoreElements();) {
+            Cleanupable o = (Cleanupable) e.nextElement();
+            try {
+                o.cleanup();
+            } catch (Throwable t) {
+		ZZLogger.exc(t, "At cleanup");
+            }
+        }
+
+        System.exit(exitcode);
+    }
+
+}