From 2430736ff134cedf5bef7b8d3f4285906576802a Mon Sep 17 00:00:00 2001
From: Jeff Hill <johill@lanl.gov>
Date: Thu, 17 Apr 2003 00:07:50 +0000
Subject: [PATCH] patch for fdManager based client tool lock up problems

---
 src/ca/cac.cpp    | 25 ++++++++-----------------
 src/ca/cac.h      |  3 +--
 src/ca/tcpiiu.cpp | 11 ++++++++++-
 src/ca/udpiiu.cpp |  8 ++++----
 4 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/src/ca/cac.cpp b/src/ca/cac.cpp
index c14664da9..7650469ff 100644
--- a/src/ca/cac.cpp
+++ b/src/ca/cac.cpp
@@ -1152,7 +1152,7 @@ bool cac::readNotifyRespAction ( epicsGuard < callbackMutex > &, tcpiiu &iiu,
     return true;
 }
 
-bool cac::eventRespAction (epicsGuard < callbackMutex > &, tcpiiu &iiu, 
+bool cac::eventRespAction ( epicsGuard < callbackMutex > &, tcpiiu &iiu, 
     const epicsTime &, const caHdrLargeArray & hdr, void * pMsgBdy )
 {   
     int caStatus;
@@ -1505,13 +1505,7 @@ void cac::disconnectNotify ( tcpiiu & iiu )
 
 void cac::initiateAbortShutdown ( tcpiiu & iiu )
 {
-    // generate some NOOP UDP traffic so that ca_pend_event()
-    // will get called in preemptive callback disabled 
-    // applications, and therefore the callback lock below
-    // will not block
-    if ( this->pudpiiu ) {
-        this->pudpiiu->wakeupMsg ();
-    }
+    cacMessageProcessingMinder msgProcMinder ( *this );
     {
         epicsGuard < callbackMutex > cbGuard ( this->cbMutex );
         epicsGuard < cacMutex > guard ( this->mutex );
@@ -1519,13 +1513,7 @@ void cac::initiateAbortShutdown ( tcpiiu & iiu )
     }
 }
 
-void cac::uninstallIIU ( tcpiiu & iiu )
-{
-    epicsGuard < callbackMutex > cbGuard ( this->cbMutex );
-    this->privateUninstallIIU ( cbGuard, iiu );
-}
-
-void cac::privateUninstallIIU ( epicsGuard < callbackMutex > & cbGuard, tcpiiu & iiu )
+void cac::uninstallIIU ( epicsGuard < callbackMutex > & cbGuard, tcpiiu & iiu )
 {
     epicsGuard < cacMutex > guard ( this->mutex );
     if ( iiu.channelCount() ) {
@@ -1593,8 +1581,11 @@ void cac::pvMultiplyDefinedNotify ( msgForMultiplyDefinedPV & mfmdpv,
     sprintf ( buf, "Channel: \"%.64s\", Connecting to: %.64s, Ignored: %.64s",
             pChannelName, pAcc, pRej );
     {
-        epicsGuard < callbackMutex > cbGuard ( this->cbMutex );
-        this->exception ( cbGuard, ECA_DBLCHNL, buf, __FILE__, __LINE__ );
+        cacMessageProcessingMinder msgProcMinder ( *this );
+        {
+            epicsGuard < callbackMutex > cbGuard ( this->cbMutex );
+            this->exception ( cbGuard, ECA_DBLCHNL, buf, __FILE__, __LINE__ );
+        }
     }
     mfmdpv.~msgForMultiplyDefinedPV ();
     this->mdpvFreeList.release ( & mfmdpv );
diff --git a/src/ca/cac.h b/src/ca/cac.h
index 9dfcf2f96..b97401e22 100644
--- a/src/ca/cac.h
+++ b/src/ca/cac.h
@@ -200,7 +200,7 @@ public:
     static unsigned highestPriorityLevelBelow ( unsigned priority );
     void initiateAbortShutdown ( tcpiiu & );
     void disconnectNotify ( tcpiiu & );
-    void uninstallIIU ( tcpiiu & ); 
+    void uninstallIIU ( epicsGuard < callbackMutex > &, tcpiiu & iiu ); 
 
 private:
     localHostName hostNameCache;
@@ -264,7 +264,6 @@ private:
     unsigned beaconAnomalyCount;
     bool preemptiveCallbackEnabled;
 
-    void privateUninstallIIU ( epicsGuard < callbackMutex > &, tcpiiu &iiu ); 
     void run ();
     void connectAllIO ( epicsGuard < cacMutex > &, nciu &chan );
     void disconnectAllIO ( epicsGuard < cacMutex > & locker, nciu & chan, bool enableCallbacks );
diff --git a/src/ca/tcpiiu.cpp b/src/ca/tcpiiu.cpp
index 85fca9ef6..d29e10fca 100644
--- a/src/ca/tcpiiu.cpp
+++ b/src/ca/tcpiiu.cpp
@@ -138,7 +138,16 @@ void tcpSendThread::run ()
 
     this->thread.exitWaitRelease ();
 
-    this->iiu.cacRef.uninstallIIU ( this->iiu );
+    {
+        // only one recv thread at a time may call callbacks
+        // - pendEvent() blocks until threads waiting for
+        // this lock get a chance to run
+        cacMessageProcessingMinder msgProcMinder ( this->iiu.cacRef );
+        {
+            epicsGuard < callbackMutex > guard ( this->cbMutex );
+            this->iiu.cacRef.uninstallIIU ( guard, this->iiu );
+        }
+    }
 
     delete & this->iiu;
 }
diff --git a/src/ca/udpiiu.cpp b/src/ca/udpiiu.cpp
index 5ae3102f3..bc71d307e 100644
--- a/src/ca/udpiiu.cpp
+++ b/src/ca/udpiiu.cpp
@@ -310,12 +310,12 @@ void udpRecvThread::run ()
 {
     epicsThreadPrivateSet ( caClientCallbackThreadId, &this->iiu );
 
-    {
-        epicsGuard < callbackMutex > cbGuard ( this->cbMutex );
-        if ( ellCount ( & this->iiu.dest ) == 0 ) { // X aCC 392
+    if ( ellCount ( & this->iiu.dest ) == 0 ) { // X aCC 392
+        cacMessageProcessingMinder msgProcMinder ( this->iiu.cacRef );
+        {
+            epicsGuard < callbackMutex > cbGuard ( this->cbMutex );
             genLocalExcep ( cbGuard, this->iiu.cacRef, ECA_NOSEARCHADDR, NULL );
         }
-
     }
 
     do {