IStatus performNavigation(IProgressMonitor monitor) throws CoreException { fAction.clearStatusLine(); assert fIndex == null; if (fIndex != null) return Status.CANCEL_STATUS; fMonitor = monitor; fIndex = CCorePlugin.getIndexManager() .getIndex( fTranslationUnit.getCProject(), IIndexManager.ADD_DEPENDENCIES | IIndexManager.ADD_DEPENDENT); try { fIndex.acquireReadLock(); } catch (InterruptedException e) { return Status.CANCEL_STATUS; } try { return ASTProvider.getASTProvider() .runOnAST(fTranslationUnit, ASTProvider.WAIT_ACTIVE_ONLY, monitor, this); } finally { fIndex.releaseReadLock(); } }