[cdt-dev] Possible race condition in cdt can result in clients accessing

[Janees Elamkulam <janees.ek@xxxxxxxxxx>]

Consider the following scenario.  
A CDT Client (extender)  listens
to CElementDelta and does some processing on receiving it by retrieving
the IASTTranslationUnit of the element. 

When an C++ element is changed, say
new field has been added to a Class. two events are generated on save,
cdt emits CElementDelta and eclipse resource emits resource change
event.  There is a possibility that Clients get stale AST from CDOM.getInstance().getTranslationUnit(IFile).
This because CodeReaderCache of SavedCodeReaderFactory  updates
only when it receives resource change event. Since the events has been
send from two different object, it is possible that  clients receive
CElementDelta before the resource change message reaches the cdt CodeReaderCache,
in such case client will be processing  based on stale copy of code.
This causes the problem.  

We have been facing this issue randomly
causing source files to get corrupted.

May be we should clear the CodeReaderCache
of  SavedResourceReaderFactor when the buffer is saved. This should
solve the problem.

Created bug:  #154056  [ https://bugs.eclipse.org/bugs/show_bug.cgi?id=154056
]

Thanks and Regards,
Janees