From 2e329813aa0b3b70f0dc45e27cc55205e01fa0ea Mon Sep 17 00:00:00 2001
From: Jeff Hill <johill@lanl.gov>
Date: Fri, 21 Sep 2001 17:09:55 +0000
Subject: [PATCH] fixed possible race condition where put notify block might be
 nilled out while it is running

---
 src/db/dbCAC.h                |  3 ---
 src/db/dbChannelIO.cpp        |  5 -----
 src/db/dbPutNotifyBlocker.cpp | 11 ++---------
 src/db/dbServiceIO.cpp        |  6 ------
 4 files changed, 2 insertions(+), 23 deletions(-)

diff --git a/src/db/dbCAC.h b/src/db/dbCAC.h
index a0967bbf1..474ed74b3 100644
--- a/src/db/dbCAC.h
+++ b/src/db/dbCAC.h
@@ -47,7 +47,6 @@ public:
     void initiatePutNotify ( epicsMutex &mutex, cacWriteNotify &notify, struct dbAddr &addr, 
             unsigned type, unsigned long count, const void *pValue );
     void cancel ();
-    void completion ();
     void show ( unsigned level ) const;
     void * operator new ( size_t size );
     void operator delete ( void *pCadaver, size_t size );
@@ -113,7 +112,6 @@ public:
             cacReadNotify &notify );
     void callStateNotify ( unsigned type, unsigned long count, 
             const struct db_field_log *pfl, cacStateNotify &notify );
-    void putNotifyCompletion ( dbPutNotifyBlocker & ); 
     void show ( unsigned level ) const;
     void * operator new ( size_t size);
     void operator delete ( void *pCadaver, size_t size );
@@ -156,7 +154,6 @@ public:
     void initiatePutNotify ( dbChannelIO &, struct dbAddr &, unsigned type, 
         unsigned long count, const void *pValue, cacWriteNotify &notify, 
         cacChannel::ioid *pId ); 
-    void putNotifyCompletion ( dbPutNotifyBlocker & ); 
     void show ( unsigned level ) const;
     void showAllIO ( const dbChannelIO &chan, unsigned level ) const;
     void destroyAllIO ( dbChannelIO & chan );
diff --git a/src/db/dbChannelIO.cpp b/src/db/dbChannelIO.cpp
index c355f4e6d..cc722c317 100644
--- a/src/db/dbChannelIO.cpp
+++ b/src/db/dbChannelIO.cpp
@@ -83,11 +83,6 @@ cacChannel::ioStatus dbChannelIO::write ( unsigned type, unsigned long count,
     return iosAsynch;
 }
 
-void dbChannelIO::putNotifyCompletion ( dbPutNotifyBlocker &blocker )
-{
-    this->serviceIO.putNotifyCompletion ( blocker );
-}
-
 void dbChannelIO::subscribe ( unsigned type, unsigned long count, 
     unsigned mask, cacStateNotify &notify, ioid *pId ) 
 {   
diff --git a/src/db/dbPutNotifyBlocker.cpp b/src/db/dbPutNotifyBlocker.cpp
index a9c067ecc..bbc2de958 100644
--- a/src/db/dbPutNotifyBlocker.cpp
+++ b/src/db/dbPutNotifyBlocker.cpp
@@ -88,19 +88,12 @@ extern "C" void putNotifyCompletion ( putNotify *ppn )
         }
     }
     else {
-        errlogPrintf ( "put notify completion pNotify = %p?\n", pBlocker->pNotify );
+        errlogPrintf ( "put notify completion with nill pNotify?\n" );
     }
+    // no need to lock here because only one put notify at a timeis lalowed to run
     memset ( &pBlocker->pn, '\0', sizeof ( pBlocker->pn ) );
     pBlocker->pNotify = 0;
     pBlocker->block.signal ();
-    pBlocker->chan.putNotifyCompletion ( *pBlocker );
-}
-
-void dbPutNotifyBlocker::completion ()
-{
-    memset ( &this->pn, '\0', sizeof ( this->pn ) );
-    this->pNotify = 0;
-    this->block.signal ();
 }
 
 void dbPutNotifyBlocker::initiatePutNotify ( epicsMutex &mutex, cacWriteNotify &notify, 
diff --git a/src/db/dbServiceIO.cpp b/src/db/dbServiceIO.cpp
index 2e062f5da..28d664bc5 100644
--- a/src/db/dbServiceIO.cpp
+++ b/src/db/dbServiceIO.cpp
@@ -255,12 +255,6 @@ void dbServiceIO::initiatePutNotify ( dbChannelIO &chan, struct dbAddr &addr,
     }
 }
 
-void dbServiceIO::putNotifyCompletion ( dbPutNotifyBlocker &blocker )
-{
-    epicsAutoMutex locker ( this->mutex );
-    blocker.completion ();
-}
-
 void dbServiceIO::destroyAllIO ( dbChannelIO & chan )
 {
     dbSubscriptionIO *pIO;