From e343acdd57e141387cb5173cedfde07241f9e2d1 Mon Sep 17 00:00:00 2001
From: Jeff Hill <johill@lanl.gov>
Date: Wed, 9 Jan 2002 00:57:23 +0000
Subject: [PATCH] dont allow local PVs to connect unless the client ctx allows
 preemptive callback

---
 src/db/dbPutNotifyBlocker.cpp | 7 +++----
 src/db/dbServiceIO.cpp        | 6 ++++++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/db/dbPutNotifyBlocker.cpp b/src/db/dbPutNotifyBlocker.cpp
index 2bc497194..6c76eae48 100644
--- a/src/db/dbPutNotifyBlocker.cpp
+++ b/src/db/dbPutNotifyBlocker.cpp
@@ -101,15 +101,14 @@ extern "C" void putNotifyCompletion ( putNotify *ppn )
     else {
         errlogPrintf ( "put notify completion with nill pNotify?\n" );
     }
-    // no need to lock here because only one put notify at a timeis lalowed to run
+    // no need to lock here because only one put notify at a time is lalowed to run
     memset ( &pBlocker->pn, '\0', sizeof ( pBlocker->pn ) );
     pBlocker->pNotify = 0;
     pBlocker->block.signal ();
 }
 
-void dbPutNotifyBlocker::initiatePutNotify ( epicsMutex &mutex, cacWriteNotify &notify, 
-        struct dbAddr &addr, unsigned type, unsigned long count, 
-        const void *pValue )
+void dbPutNotifyBlocker::initiatePutNotify ( epicsMutex &mutex, cacWriteNotify & notify, 
+        struct dbAddr & addr, unsigned type, unsigned long count, const void * pValue )
 {
     int status;
 
diff --git a/src/db/dbServiceIO.cpp b/src/db/dbServiceIO.cpp
index 557ef7ad5..ac3b24549 100644
--- a/src/db/dbServiceIO.cpp
+++ b/src/db/dbServiceIO.cpp
@@ -90,6 +90,12 @@ cacChannel *dbServiceIO::createChannel (
     if ( status ) {
         return 0;
     }
+	else if ( ! ca_preemtive_callback_is_enabled () ) {
+		errlogPrintf ( 
+			"dbServiceIO: preemptive callback required for 
+			\n memory interfacing of CA channels to the DB\n" );
+		return 0;
+	}
     else {
         return new dbChannelIO ( notify, addr, *this ); 
     }