1 files changed, 27 insertions, 5 deletions

diff --git a/src/IvyClient.java b/src/IvyClient.java
index b0c1200..af42342 100755
--- a/src/IvyClient.java
+++ b/src/IvyClient.java
@@ -103,10 +103,11 @@ public class IvyClient implements Runnable {
   final static char newLineChar = '\n';
 
   // private variables
+  private final static int MAXPONGCALLBACKS = 10;
   private static int pingSerial = 0;
   private static Integer csMutex=new Integer(0);
   private static int clientSerial=0;	/* an unique ID for each IvyClient */
-  private Stack PCHStack = new Stack();
+  private Hashtable PingCallbacksTable = new Hashtable();
   
   private String messages_classes[] = null;
   private Ivy bus;
@@ -246,7 +247,7 @@ public class IvyClient implements Runnable {
    * received
    */
   public void ping(PingCallback pc) throws IvyException {
-    PCHStack.push(new PingCallbackHolder(pc));
+    PCHadd(pingSerial,pc);
     sendString(Ping,pingSerial++,"");
   }
 
@@ -488,7 +489,7 @@ public class IvyClient implements Runnable {
 	}
 	break;
       case Pong:
-        ((PingCallbackHolder)PCHStack.pop()).run();
+        PCHget(msgId);
 	break;
       case Ping:
 	sendString(Pong,msgId.intValue(),"");
@@ -591,16 +592,37 @@ public class IvyClient implements Runnable {
     traceDebug(s);
   }
 
+  void PCHadd(int serial,PingCallback pc) {
+    PingCallbacksTable.put(new Integer(serial),new PingCallbackHolder(pc));
+    if (PingCallbacksTable.size()>MAXPONGCALLBACKS) {
+      // more than MAXPONGCALLBACKS callbacks, we ought to limit to prevent a
+      // memory leak
+      // TODO remove the first
+      Integer smallest=(Integer)new TreeSet(PingCallbacksTable.keySet()).first();
+      PingCallbackHolder pch = (PingCallbackHolder)PingCallbacksTable.remove(smallest);
+      System.err.println("no response from "+getApplicationName()+" to ping "+smallest+" after "+pch.age()+" ms, discarding");
+    }
+  }
+
+  void PCHget(Integer serial) {
+    PingCallbackHolder pc = (PingCallbackHolder)PingCallbacksTable.remove(serial);
+    if (pc==null) {
+      System.err.println("warning: pong received for a long lost callback");
+      return;
+    }
+    pc.run();
+  }
+
   private class PingCallbackHolder {
     PingCallback pc;
     long epoch;
+    int age() { return (int)(System.currentTimeMillis()-epoch); }
     PingCallbackHolder(PingCallback pc) {
       this.pc=pc;
       epoch=System.currentTimeMillis();
-      PCHStack.push(this);
     }
     void run() {
-      pc.pongReceived(IvyClient.this,(int)(System.currentTimeMillis()-epoch));
+      pc.pongReceived(IvyClient.this,age());
     }
   }