From 4359938ed6fd4a10e42f7919ec3096bb1745a0eb Mon Sep 17 00:00:00 2001
From: Jeff Hill <johill@lanl.gov>
Date: Wed, 6 Aug 2003 17:42:55 +0000
Subject: [PATCH] added virtual circuit free list and fixed race condition in
 virtual circuit shutdown sequence

---
 src/ca/cac.cpp    | 19 +++++++++++++++----
 src/ca/cac.h      |  5 ++++-
 src/ca/tcpiiu.cpp | 23 ++++++++++++++++-------
 3 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/src/ca/cac.cpp b/src/ca/cac.cpp
index 6e92d2a37..17863ed46 100644
--- a/src/ca/cac.cpp
+++ b/src/ca/cac.cpp
@@ -43,6 +43,7 @@
 #include "bhe.h"
 #include "net_convert.h"
 #include "autoPtrDestroy.h"
+#include "autoPtrFreeList.h"
 
 static const char *pVersionCAC = 
     "@(#) " EPICS_VERSION_STRING 
@@ -269,10 +270,15 @@ cac::~cac ()
     // this will block for oustanding sends to go out so dont 
     // hold a lock while waiting
     //
-    while ( this->serverList.count() ) {
-        this->iiuUninstall.wait ();
+    {
+        epicsGuard < cacMutex > guard ( this->mutex );
+        while ( this->serverList.count() ) {
+            epicsGuardRelease < cacMutex > unguard ( guard );
+            this->iiuUninstall.wait ();
+        }
     }
 
+
     if ( this->pudpiiu ) {
         delete this->pudpiiu;
     }
@@ -566,7 +572,9 @@ bool cac::transferChanToVirtCircuit (
         }
         else {
             try {
-                epics_auto_ptr < tcpiiu > pnewiiu ( new tcpiiu ( 
+                autoPtrFreeList < tcpiiu, 32, epicsMutexNOOP > pnewiiu (
+                            this->freeListVirtualCircuit,
+                            new ( this->freeListVirtualCircuit ) tcpiiu ( 
                             *this, this->cbMutex, this->connTMO, this->timerQueue,
                             addr, this->comBufMemMgr, minorVersionNumber, 
                             this->ipToAEngine, pChan->getPriority() ) );
@@ -1528,8 +1536,9 @@ void cac::initiateAbortShutdown ( tcpiiu & iiu )
     iiu.removeAllChannels ( cbGuard, guard, *this );
 }
 
-void cac::uninstallIIU ( epicsGuard < callbackMutex > & cbGuard, tcpiiu & iiu )
+void cac::destroyIIU ( tcpiiu & iiu )
 {
+    epicsGuard < callbackMutex > cbGuard ( this->cbMutex );
     epicsGuard < cacMutex > guard ( this->mutex );
     if ( iiu.channelCount() ) {
         char hostNameTmp[64];
@@ -1550,6 +1559,8 @@ void cac::uninstallIIU ( epicsGuard < callbackMutex > & cbGuard, tcpiiu & iiu )
 
     this->serverTable.remove ( iiu );
     this->serverList.remove ( iiu );
+    iiu.~tcpiiu ();
+    this->freeListVirtualCircuit.release ( & iiu );
 
     // signal iiu uninstal event so that cac can properly shut down
     this->iiuUninstall.signal();
diff --git a/src/ca/cac.h b/src/ca/cac.h
index c622ee9c4..4823a2184 100644
--- a/src/ca/cac.h
+++ b/src/ca/cac.h
@@ -189,7 +189,7 @@ public:
     static unsigned highestPriorityLevelBelow ( unsigned priority );
     void initiateAbortShutdown ( tcpiiu & );
     void disconnectNotify ( tcpiiu & );
-    void uninstallIIU ( epicsGuard < callbackMutex > &, tcpiiu & iiu ); 
+    void destroyIIU ( tcpiiu & iiu ); 
 
 private:
     localHostName hostNameCache;
@@ -213,6 +213,9 @@ private:
     resTable < bhe, inetAddrID > beaconTable;
     resTable < tcpiiu, caServerID > serverTable;
     tsDLList < tcpiiu > serverList;
+    tsFreeList 
+        < class tcpiiu, 32, epicsMutexNOOP > 
+            freeListVirtualCircuit;
     tsFreeList 
         < class netReadNotifyIO, 1024, epicsMutexNOOP > 
             freeListReadNotifyIO;
diff --git a/src/ca/tcpiiu.cpp b/src/ca/tcpiiu.cpp
index 01471691a..0a9083f49 100644
--- a/src/ca/tcpiiu.cpp
+++ b/src/ca/tcpiiu.cpp
@@ -151,15 +151,9 @@ void tcpSendThread::run ()
     }
 
     this->iiu.recvThread.exitWait ();
-
     this->thread.exitWaitRelease ();
 
-    {
-        epicsGuard < callbackMutex > guard ( this->cbMutex );
-        this->iiu.cacRef.uninstallIIU ( guard, this->iiu );
-    }
-
-    delete & this->iiu;
+    this->iiu.cacRef.destroyIIU ( this->iiu );
 }
 
 unsigned tcpiiu::sendBytes ( const void *pBuf, 
@@ -1488,4 +1482,19 @@ void tcpSendThread::interruptSocketSend ()
     }
 }
 
+void tcpiiu::operator delete ( void * pCadaver )
+{
+    // Visual C++ .net appears to require operator delete if
+    // placement operator delete is defined? I smell a ms rat
+    // because if I declare placement new and delete, but
+    // comment out the placement delete definition there are
+    // no undefined symbols.
+    errlogPrintf ( "%s:%d this compiler is confused about "
+        "placement delete - memory was probably leaked",
+        __FILE__, __LINE__ );
+}
+
+
+
+