Completion "hangs" with no response #743

Getting rid of infinite waiting in LSContentAssistProcessor

Issue: #743

org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/completion/LSContentAssistProcessor.java

@@ -64,6 +64,7 @@
 public class LSContentAssistProcessor implements IContentAssistProcessor {
 
 	private static final long TRIGGERS_TIMEOUT = 50;
+	private static final long GET_TIMEOUT = 1000;
 	private static final long CONTEXT_INFORMATION_TIMEOUT = 1000;
 	private IDocument currentDocument;
 	private String errorMessage;
@@ -111,7 +112,7 @@ public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int
 					.withFilter(capabilities -> capabilities.getCompletionProvider() != null)
 					.collectAll((w, ls) -> ls.getTextDocumentService().completion(param)
 							.thenAccept(completion -> proposals.addAll(toProposals(document, offset, completion, w))));
-			this.completionLanguageServersFuture.get();
+			this.completionLanguageServersFuture.get(GET_TIMEOUT, TimeUnit.MILLISECONDS);
 		} catch (ResponseErrorException | ExecutionException e) {
 			if (!CancellationUtil.isRequestCancelledException(e)) { // do not report error if the server has cancelled the request
 				LanguageServerPlugin.logError(e);
@@ -123,6 +124,8 @@ public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int
 			this.errorMessage = createErrorMessage(offset, e);
 			Thread.currentThread().interrupt();
 			return createErrorProposal(offset, e);
+		} catch (TimeoutException e) {
+			LanguageServerPlugin.logWarning("Could not get completions due to timeout after " + GET_TIMEOUT + " milliseconds", e); //$NON-NLS-1$ //$NON-NLS-2$
 		}
 
 		final var completeProposals = new LSCompletionProposal[proposals.size()];
@@ -255,7 +258,7 @@ public IContextInformation[] computeContextInformation(ITextViewer viewer, int o
 			Thread.currentThread().interrupt();
 			return new IContextInformation[] { /* TODO? show error in context information */ };
 		} catch (TimeoutException e) {
-			LanguageServerPlugin.logWarning("Could not compute  context information due to timeout after " + CONTEXT_INFORMATION_TIMEOUT + " milliseconds", e);  //$NON-NLS-1$//$NON-NLS-2$
+			LanguageServerPlugin.logWarning("Could not compute context information due to timeout after " + CONTEXT_INFORMATION_TIMEOUT + " milliseconds", e);  //$NON-NLS-1$//$NON-NLS-2$
 			return new IContextInformation[] { /* TODO? show error in context information */ };
 		}
 		return contextInformations.toArray(new IContextInformation[0]);