Merge lp:~bhill/epics-base/pcas-deadlock-fix-3.14 into lp:~epics-core/epics-base/3.14

[Bruce Hill]

Avoid deadlock when by moving call to casPVI::nativeCount()
out of the casEventSys processing to the casPVI constructor.
The nativeCount (max array size) doesn't change for a casPVI
instance so no need to lock the casPVI mutex each time we need
to test it's size.

[Andrew Johnson (anj)]

Thanks Bruce, much appreciated!

review: Approve

=== modified file 'src/cas/generic/casChannelI.cc'
--- src/cas/generic/casChannelI.cc	2016-05-22 03:43:09 +0000
+++ src/cas/generic/casChannelI.cc	2016-12-07 09:42:35 +0000
@@ -21,6 +21,7 @@
     casChannel & chanIn, casPVI & pvIn, ca_uint32_t cidIn ) :
         privateForPV ( clientIn, *this ),
         pv ( pvIn ), 
+        maxElem( pvIn.nativeCount() ),
         chan ( chanIn ), 
         cid ( cidIn ), 
         serverDeletePending ( false ), 

=== modified file 'src/cas/generic/casChannelI.h'
--- src/cas/generic/casChannelI.h	2016-05-22 03:43:09 +0000
+++ src/cas/generic/casChannelI.h	2016-12-07 09:42:35 +0000
@@ -45,6 +45,7 @@
 	void clearOutstandingReads ();
 	void postAccessRightsEvent ();
     const gddEnumStringTable & enumStringTable () const;
+	ca_uint32_t getMaxElem () const;
 	void setOwner ( const char * const pUserName, 
 		const char * const pHostName );
 	bool readAccess () const;
@@ -58,6 +59,7 @@
     chanIntfForPV privateForPV;
 	tsDLList < casAsyncIOI > ioList;
 	casPVI & pv;
+	ca_uint32_t maxElem;
     casChannel & chan;
 	caResId cid; // client id 
     bool serverDeletePending;
@@ -77,6 +79,11 @@
 	return this->pv;
 }
 
+inline  ca_uint32_t casChannelI::getMaxElem () const 
+{
+    return this->maxElem;
+}
+
 inline const caResId casChannelI::getCID () 
 {
 	return this->cid;

=== modified file 'src/cas/generic/casStrmClient.cc'
--- src/cas/generic/casStrmClient.cc	2016-11-30 17:58:24 +0000
+++ src/cas/generic/casStrmClient.cc	2016-12-07 09:42:35 +0000
@@ -409,7 +409,7 @@
     //
     // element count out of range ?
     //
-    if ( ctx.msg.m_count > pChan->getPVI().nativeCount() ||
+    if ( ctx.msg.m_count > pChan->getMaxElem() ||
          ( !allowdyn && ctx.msg.m_count == 0u ) ) {
         return ECA_BADCOUNT;
     }
@@ -895,7 +895,7 @@
     gdd * pDBRDD = 0;
     if ( completionStatus == S_cas_success ) {
         caStatus status = createDBRDD ( msg.m_dataType, count,
-                chan.getPVI().nativeCount(), pDBRDD );
+                chan.getMaxElem(), pDBRDD );
         if ( status != S_cas_success ) {
             caStatus ecaStatus;
             if ( status == S_cas_badType ) {
@@ -1866,7 +1866,7 @@
     // the protocol buffer.
     //
     assert ( nativeTypeDBR <= 0xffff );
-    aitIndex nativeCount = chan.getPVI().nativeCount();
+    aitIndex nativeCount = chan.getMaxElem();
     assert ( nativeCount <= 0xffffffff );
     assert ( hdr.m_cid == chan.getCID() );
     status = this->out.copyInHeader ( CA_PROTO_CREATE_CHAN, 0,
@@ -2626,7 +2626,7 @@
     {
         gdd * pDD = 0;
         caStatus status = createDBRDD ( pHdr->m_dataType, pHdr->m_count,
-                this->ctx.getChannel()->getPVI().nativeCount(), pDD );
+                this->ctx.getChannel()->getMaxElem(), pDD );
         if ( status != S_cas_success ) {
             return status;
         }