Changed Field Fix

documentation/RELEASE_NOTES.md

@@ -2,6 +2,10 @@
 
 This document summarizes the changes to the module between releases.
 
+## Release 4.7.2
+
+* Resolved issue with changed field set in the case where the top level (master) field ("_") is not requested by the client, but the master field callback causes all fields to be marked as updated, rather than only those fields that have actually been modified.
+
 ## Release 4.7.1 (EPICS 7.0.8, Dec 2023)
 
 * Added data distributor plugin which can be used for distributing data between 

src/copy/pvCopy.cpp

@@ -432,6 +432,7 @@ bool PVCopy::init(epics::pvData::PVStructurePtr const &pvRequest)
     PVStructurePtr pvMasterStructure = pvMaster;
     size_t len = pvRequest->getPVFields().size();
     bool entireMaster = false;
+    requestHasMasterField = false;
     PVStructurePtr pvOptions;
     if(len==0) {
         entireMaster = true;
@@ -441,6 +442,9 @@ bool PVCopy::init(epics::pvData::PVStructurePtr const &pvRequest)
         // then assume the top level PV structure is requested
         PVStructurePtr masterFieldPtr = pvMaster->getSubField<PVStructure>("_");
         PVStructurePtr requestFieldPtr = pvRequest->getSubField<PVStructure>("_");
+        if (requestFieldPtr) {
+            requestHasMasterField = true;
+        }
         if (!masterFieldPtr && requestFieldPtr) {
             entireMaster = true;
             pvOptions = requestFieldPtr->getSubField<PVStructure>("_options");

src/database/pvRecord.cpp

@@ -481,27 +481,30 @@ void PVRecordStructure::init()
     for(size_t i=0; i<numFields; i++) {
         PVFieldPtr pvField = pvFields[i];
         if(pvField->getField()->getType()==structure) {
-             PVStructurePtr xxx = static_pointer_cast<PVStructure>(pvField);
-             PVRecordStructurePtr pvRecordStructure(
+            PVStructurePtr xxx = static_pointer_cast<PVStructure>(pvField);
+            PVRecordStructurePtr pvRecordStructure(
                  new PVRecordStructure(xxx,self,pvRecord));
-             pvRecordFields->push_back(pvRecordStructure);
-             pvRecordStructure->init();
+            pvRecordFields->push_back(pvRecordStructure);
+            pvRecordStructure->init();
         } else {
-             PVRecordFieldPtr pvRecordField(
+            PVRecordFieldPtr pvRecordField(
                 new PVRecordField(pvField,self,pvRecord));
-             pvRecordFields->push_back(pvRecordField);
-             pvRecordField->init();
-             // Master field listeners will be called before
-             // calling listeners for the first subfield
-             if (!masterFieldCallbackSet) {
-                 masterFieldCallbackSet = true;
-                 // Find master field
-                 PVRecordStructurePtr p = pvRecordField->parent.lock();
-                 while (p) {
-                     pvRecordField->master = p;
-                     p = p->parent.lock();
-                 }
-             }
+            pvRecordFields->push_back(pvRecordField);
+            pvRecordField->init();
+            // Master field listeners will be called before
+            // calling listeners for the first subfield
+            if (!masterFieldCallbackSet) {
+                masterFieldCallbackSet = true;
+                // Find master field
+                PVRecordStructurePtr p = pvRecordField->parent.lock();
+                while (p) {
+                    PVRecordStructurePtr p2 = p->parent.lock();
+                    if (!p2) {
+                        pvRecordField->master = p;
+                    }
+                    p = p2;
+                }
+            }
         }
     }
 }

src/pv/pvStructureCopy.h

@@ -167,6 +167,10 @@ class epicsShareClass PVCopy :
      *  name is the subField name and value is the subField value.
      */
     epics::pvData::PVStructurePtr getOptions(std::size_t fieldOffset);
+    /**
+     * Is master field requested?
+     */
+    bool isMasterFieldRequested() const {return requestHasMasterField;}
     /**
      * For debugging.
      */
@@ -183,6 +187,7 @@ class epicsShareClass PVCopy :
     CopyNodePtr headNode;
     epics::pvData::PVStructurePtr cacheInitStructure;
     epics::pvData::BitSetPtr ignorechangeBitSet;
+    bool requestHasMasterField;
 
     void traverseMaster(
         CopyNodePtr const &node,

src/pvAccess/monitorFactory.cpp

@@ -292,6 +292,12 @@ void MonitorLocal::dataPut(PVRecordFieldPtr const & pvRecordField)
     {
         cout << "MonitorLocal::dataPut(pvRecordField)" << endl;
     }
+    // If this record field is the master field, and the master field was not
+    // requested, we do not proceed with copy
+    bool isMasterField = pvRecordField->getPVRecord()->getPVStructure()->getFieldOffset()==0;
+    if (isMasterField && !pvCopy->isMasterFieldRequested()) {
+        return;
+    }
     if(state!=active) return;
     {
         Lock xx(mutex);

test/src/Makefile

@@ -33,3 +33,8 @@ TESTPROD_HOST += testPVAServer
 testPVAServer_SRCS += testPVAServer.cpp
 testHarness_SRCS += testPVAServer.cpp
 TESTS += testPVAServer
+
+TESTPROD_HOST += testChannelMonitor
+testChannelMonitor_SRCS += testChannelMonitor.cpp
+testHarness_SRCS += testChannelMonitor.cpp
+TESTS += testChannelMonitor