detect incoming-datagram buffer overflow

direct/src/distributed/ConnectionRepository.py

@@ -310,11 +310,14 @@ class ConnectionRepository(DirectObject.DirectObject, CConnectionRepository):
     def startReaderPollTask(self):
         # Stop any tasks we are running now
         self.stopReaderPollTask()
+        self.accept(CConnectionRepository.getOverflowEventName(),
+                    self.handleReaderOverflow)
         taskMgr.add(self.readerPollUntilEmpty, "readerPollTask",
                     priority = self.taskPriority)
 
     def stopReaderPollTask(self):
         taskMgr.remove("readerPollTask")
+        self.ignore(CConnectionRepository.getOverflowEventName())
 
     def readerPollUntilEmpty(self, task):
         while self.readerPollOnce():
@@ -333,6 +336,11 @@ class ConnectionRepository(DirectObject.DirectObject, CConnectionRepository):
             self.lostConnection()
         return 0
 
+    def handleReaderOverflow(self):
+        # this is called if the incoming-datagram queue overflowed and
+        # we lost some data. Override and handle if desired.
+        pass
+
     def lostConnection(self):
         # This should be overrided by a derived class to handle an
         # unexpectedly lost connection to the gameserver.

direct/src/distributed/cConnectionRepository.I

@@ -182,6 +182,17 @@ get_msg_type() const {
   return _msg_type;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: CConnectionRepository::get_overflow_event_name
+//       Access: Published
+//  Description: Returns event string that will be thrown if the
+//               datagram reader queue overflows.
+////////////////////////////////////////////////////////////////////
+INLINE const string &CConnectionRepository::
+get_overflow_event_name() {
+  return _overflow_event_name;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: CConnectionRepository::set_simulated_disconnect
 //       Access: Published

direct/src/distributed/cConnectionRepository.cxx

@@ -24,6 +24,9 @@
 #include "httpChannel.h"
 #include "urlSpec.h"
 #include "datagramIterator.h"
+#include "throw_event.h"
+
+const string CConnectionRepository::_overflow_event_name = "CRDatagramOverflow";
 
 ////////////////////////////////////////////////////////////////////
 //     Function: CConnectionRepository::Constructor
@@ -345,6 +348,10 @@ do_check_datagram() {
 #ifdef HAVE_NSPR
   if (_nspr_conn) {
     _nspr_conn->consider_flush();
+    if (_qcr.get_overflow_flag()) {
+      throw_event(get_overflow_event_name());
+      _qcr.reset_overflow_flag();
+    }
     return (_qcr.data_available() && _qcr.get_data(_dg));
   }
 #endif  // HAVE_NSPR

direct/src/distributed/cConnectionRepository.h

@@ -83,6 +83,8 @@ PUBLISHED:
   INLINE unsigned char get_sec_code() const;
   INLINE unsigned int get_msg_type() const;
 
+  INLINE static const string &get_overflow_event_name();
+
   bool is_connected();
 
   bool send_datagram(const Datagram &dg);
@@ -124,6 +126,8 @@ private:
   unsigned int _msg_sender;
   unsigned char _sec_code;
   unsigned int _msg_type;
+
+  static const string _overflow_event_name;
 };
 
 #include "cConnectionRepository.I"