epics/pvAccess
0
0
Fork 0
Code Issues Pull Requests Projects Wiki Activity

client: (shallow) copy into Monitor::root

Browse Source 
Avoid exposing refs. from monitor queue
which might then be used after release().
Also allows users the possibility of caching
getSubField() until root.get() actually changes.
This commit is contained in:
Michael Davidsaver
2018-02-21 11:19:21 -08:00
parent 79ada524fa
commit b5bf6a4ccd
2 changed files with 35 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/client/clientMonitor.cpp
View File

@@ -196,16 +196,29 @@ bool Monitor::poll()
Guard G(impl->mutex);
if(!impl->done && impl->last.next()) {
root = impl->last->pvStructurePtr;
const epics::pvData::PVStructurePtr& ptr = impl->last->pvStructurePtr;
changed = *impl->last->changedBitSet;
overrun = *impl->last->overrunBitSet;
/* copy the exposed PVStructure for two reasons.
* 1. Prevent accidental use of shared container after release()
* 2. Allows caller to cache results of getSubField() until root.get() changes.
*/
if(!root || (void*)root->getField().get()!=(void*)ptr->getField().get()) {
// initial connection, or new type
root = pvd::getPVDataCreate()->createPVStructure(ptr); // also calls copyUnchecked()
} else {
// same type
const_cast<pvd::PVStructure&>(*root).copyUnchecked(*ptr, changed);
}
impl->seenEmpty = false;
} else {
root.reset();
changed.clear();
overrun.clear();
impl->seenEmpty = true;
}
return impl->seenEmpty = !!root;
return !impl->seenEmpty;
}
bool Monitor::complete() const