[ns] Bug report/fix: Memory leaks in scheduler.cc and tcp-vegas.cc

[Eric Weigle <ehw@lanl.gov>]

Good afternoon-

I've tracked down a couple of memory leaks. The one in Vegas probably doesn't
affect most people, but there's one in the Heap code of scheduler.cc that might
affect a lot of people- when resizing the heap the old heap memory is not freed.
Whoever switched the code from looping to a memcpy accidentally commented out
the delete of the old memory (which was bad code anyway, since it left out the
[] for an array).

----------------------------------Begin patch-----------------------------------
--- scheduler.cc.orig	Tue Oct 31 13:03:47 2000
+++ scheduler.cc	Tue Oct 31 13:05:18 2000
@@ -416,7 +416,7 @@
 		memcpy(h_elems, he_old, osize*sizeof(Heap::Heap_elem));
-		//for (i = 0; i < osize; i++)
-		//	h_elems[i] = he_old[i];
-		//delete he_old;
+		delete [] he_old;
 	}
 
 	i = h_size++;
-----------------------------------End patch------------------------------------

The bug in Vegas is encountered when agents are being re-used. The reset()
function clears all the variables, including the sequence number. Unfortunately,
memory is being allocated in output() based upon the value of the sequence
number- so Vegas agents will lose memory every time output is called after a
reset (e.g., every time they are re-used). Also, the destructor never freed the
memory anyway. The following patch creates a proper constructor/destructor and
fixes the reset() function.

----------------------------------Begin patch-----------------------------------
--- tcp-vegas.cc.orig	Tue Oct 31 12:39:56 2000
+++ tcp-vegas.cc	Tue Oct 31 13:12:20 2000
@@ -54,6 +54,16 @@
 
 VegasTcpAgent::VegasTcpAgent() : TcpAgent()
 {
+	v_sendtime_ = NULL;
+	v_transmits_ = NULL;
+}
+
+VegasTcpAgent::~VegasTcpAgent()
+{
+	if (v_sendtime_)
+		delete [] v_sendtime_;
+	if (v_transmits_)
+		delete [] v_transmits_;
 }
 
 void
@@ -100,6 +110,15 @@
 	v_incr_ = 0;
 	v_inc_flag_ = 1;
 
+	if (v_sendtime_) {
+		delete [] v_sendtime_;
+		v_sendtime_ = NULL;
+	}
+	if (v_transmits_) {
+		delete [] v_transmits_;
+		v_transmits_ = NULL;
+	}
+
 	TcpAgent::reset();
 }
-----------------------------------End patch------------------------------------
 
Thanks,
-Eric

--------------------------------------------
 Eric H. Weigle   CCS-1, RADIANT team
 ehw@lanl.gov     Los Alamos National Lab
 (505) 665-4937   http://home.lanl.gov/ehw/
--------------------------------------------