2004-09-04 jrandom

* Added some basic guards to prevent multiple instances from running.
       Specifically, a file "router.ping" in the install directory which is
       written to once a minute - if that file exists and has been modified
       within the last minute, refuse to start up.  In turn, adjust the
       service wrapper to wait a minute before restarting a crashed JVM.
     * Create a "work" directory in the I2P install dir which Jetty will
       use for all of its temporary files.
     * Tell the browser not to cache most of the router console's pages.

apps/routerconsole/jsp/nav.jsp

@@ -1,4 +1,10 @@
-<% 
+<% response.setHeader("Pragma", "no-cache");
+   response.setHeader("Cache-Control","no-cache");
+   response.setDateHeader("Expires", 0);
+   // the above will b0rk if the servlet engine has already flushed
+   // the response prior to including nav.jsp, so nav should be 
+   // near the top
+   
    if (request.getParameter("i2p.contextId") != null) {
        session.setAttribute("i2p.contextId", request.getParameter("i2p.contextId")); 
    }%>

build.xml

@@ -206,6 +206,8 @@
         <copy file="history.txt" todir="pkg-temp/" />
         <mkdir dir="pkg-temp/docs" />
         <copy file="readme.html" todir="pkg-temp/docs/" />
+        <mkdir dir="pkg-temp/work" />
+        <touch file="pkg-temp/work/ignore.this" />
     </target>
     <target name="tarball" depends="preppkg">
         <tar compression="bzip2" destfile="i2p.tar.bz2">

history.txt

@@ -1,4 +1,14 @@
-$Id: history.txt,v 1.5 2004/09/03 14:46:08 jrandom Exp $
+$Id: history.txt,v 1.6 2004/09/04 00:41:42 jrandom Exp $
+
+2004-09-04  jrandom
+    * Added some basic guards to prevent multiple instances from running.
+      Specifically, a file "router.ping" in the install directory which is
+      written to once a minute - if that file exists and has been modified
+      within the last minute, refuse to start up.  In turn, adjust the 
+      service wrapper to wait a minute before restarting a crashed JVM.
+    * Create a "work" directory in the I2P install dir which Jetty will
+      use for all of its temporary files.
+    * Tell the browser not to cache most of the router console's pages.
 
 2004-09-04  jrandom
     * Update the SDK to automatically reconnect indefinitely with an 

installer/resources/wrapper.conf

@@ -100,7 +100,7 @@ wrapper.jvm_exit.timeout=60
 wrapper.jvm_exit.timeout=30
 
 # give the OS 30s to clear all the old sockets / etc before restarting
-#wrapper.restart.delay=30
+wrapper.restart.delay=60
 
 # use the wrapper's internal timer thread.  otherwise this would 
 # force a restart of the router during daylight savings time as well

router/java/src/net/i2p/router/Router.java

@@ -82,6 +82,14 @@ public class Router {
     public Router(Properties envProps) { this(null, envProps); }
     public Router(String configFilename) { this(configFilename, null); }
     public Router(String configFilename, Properties envProps) {
+        if (!beginMarkingLiveliness(envProps)) {
+            System.err.println("ERROR: There appears to be another router already running!");
+            System.err.println("       Please make sure to shut down old instances before starting up");
+            System.err.println("       a new one.  If you are positive that no other instance is running,");
+            System.err.println("       please delete the file " + getPingFile(envProps));
+            System.exit(-1);
+        }
+
         _config = new Properties();
         _context = new RouterContext(this, envProps);
         if (configFilename == null)
@@ -554,6 +562,8 @@ public class Router {
         dumpStats();
         _log.log(Log.CRIT, "Shutdown(" + exitCode + ") complete", new Exception("Shutdown"));
         try { _context.logManager().shutdown(); } catch (Throwable t) { }
+        File f = new File(getPingFile());
+        f.delete();
         if (_killVMOnEnd) {
             try { Thread.sleep(1000); } catch (InterruptedException ie) {}
             Runtime.getRuntime().halt(exitCode);
@@ -685,6 +695,77 @@ public class Router {
         r.runRouter();
     }
     
+    private static String getPingFile(Properties envProps) {
+        if (envProps != null) 
+            return envProps.getProperty("router.pingFile", "router.ping");
+        else
+            return "router.ping";
+    }
+    private String getPingFile() {
+        return _context.getProperty("router.pingFile", "router.ping");
+    }
+    
+    private static final long LIVELINESS_DELAY = 60*1000;
+    
+    /** 
+     * Start a thread that will periodically update the file "router.ping", but if 
+     * that file already exists and was recently written to, return false as there is
+     * another instance running
+     * 
+     * @return true if the router is the only one running 
+     */
+    private boolean beginMarkingLiveliness(Properties envProps) {
+        String filename = getPingFile(envProps);
+        File f = new File(filename);
+        if (f.exists()) {
+            long lastWritten = f.lastModified();
+            if (System.currentTimeMillis()-lastWritten > LIVELINESS_DELAY) {
+                System.err.println("WARN: Old router was not shut down gracefully, deleting router.ping");
+                f.delete();
+            } else {
+                return false;
+            }
+        }
+        // not an I2PThread for context creation issues
+        Thread t = new Thread(new MarkLiveliness(f));
+        t.setName("Mark router liveliness");
+        t.setDaemon(true);
+        t.start();
+        return true;
+    }
+    
+    private class MarkLiveliness implements Runnable {
+        private File _pingFile;
+        public MarkLiveliness(File f) {
+            _pingFile = f;
+        }
+        public void run() {
+            _pingFile.deleteOnExit();
+            do {
+                ping();
+                try { Thread.sleep(LIVELINESS_DELAY); } catch (InterruptedException ie) {}
+            } while (_isAlive);
+            _pingFile.delete();
+        }
+        
+        private void ping() {
+            FileOutputStream fos = null;
+            try { 
+                fos = new FileOutputStream(_pingFile);
+                fos.write(("" + System.currentTimeMillis()).getBytes());
+            } catch (IOException ioe) {
+                if (_log != null) {
+                    _log.log(Log.CRIT, "Error writing to ping file", ioe);
+                } else {
+                    System.err.println("Error writing to ping file");
+                    ioe.printStackTrace();
+                }
+            } finally {
+                if (fos != null) try { fos.close(); } catch (IOException ioe) {}
+            }
+        }
+    }
+    
     
     private static int __id = 0;
     private class ShutdownHook extends Thread {

router/java/src/net/i2p/router/RouterVersion.java

@@ -15,9 +15,9 @@ import net.i2p.CoreVersion;
  *
  */
 public class RouterVersion {
-    public final static String ID = "$Revision: 1.21 $ $Date: 2004/09/03 14:46:07 $";
+    public final static String ID = "$Revision: 1.22 $ $Date: 2004/09/04 00:41:42 $";
     public final static String VERSION = "0.4";
-    public final static long BUILD = 4;
+    public final static long BUILD = 5;
     public static void main(String args[]) {
         System.out.println("I2P Router version: " + VERSION);
         System.out.println("Router ID: " + RouterVersion.ID);