CodeAssist: Fix leaking asynchronous processors

Currently the ownership of the processor is unknown to the codeassist
when running an async operation. Move the ownership of the processor to
the assist and delete the processor after the proposal was completed.

Change-Id: I6a2e023c47cbc876669dba866bee12b481447cb7
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/clangcodemodel/clangbackendreceiver.cpp

@@ -190,8 +190,7 @@ void BackendReceiver::completions(const CompletionsMessage &message)
                  << "items";
 
     const quint64 ticket = message.ticketNumber;
-    QScopedPointer<ClangCompletionAssistProcessor> processor(m_assistProcessorsTable.take(ticket));
+    if (ClangCompletionAssistProcessor *processor = m_assistProcessorsTable.take(ticket))
-    if (processor)
         processor->handleAvailableCompletions(message.codeCompletions);
 }
 

src/plugins/languageclient/client.cpp

@@ -40,6 +40,7 @@
 #include <projectexplorer/project.h>
 #include <projectexplorer/session.h>
 #include <texteditor/codeassist/documentcontentcompletion.h>
+#include <texteditor/codeassist/iassistprocessor.h>
 #include <texteditor/syntaxhighlighter.h>
 #include <texteditor/tabsettings.h>
 #include <texteditor/textdocument.h>
@@ -146,6 +147,8 @@ Client::~Client()
                 highlighter->clearAllExtraFormats();
         }
     }
+    for (IAssistProcessor *processor : m_runningAssistProcessors)
+        processor->setAsyncProposalAvailable(nullptr);
     updateEditorToolBar(m_openedDocument.keys());
 }
 
@@ -902,6 +905,16 @@ bool Client::isSupportedUri(const DocumentUri &uri) const
                                        Utils::mimeTypeForFile(uri.toFilePath().fileName()).name());
 }
 
+void Client::addAssistProcessor(TextEditor::IAssistProcessor *processor)
+{
+    m_runningAssistProcessors.insert(processor);
+}
+
+void Client::removeAssistProcessor(TextEditor::IAssistProcessor *processor)
+{
+    m_runningAssistProcessors.remove(processor);
+}
+
 bool Client::needsRestart(const BaseSettings *settings) const
 {
     QTC_ASSERT(settings, return false);
@@ -942,6 +955,9 @@ bool Client::reset()
         document->disconnect(this);
     for (TextEditor::TextDocument *document : m_resetAssistProvider.keys())
         resetAssistProviders(document);
+    for (TextEditor::IAssistProcessor *processor : m_runningAssistProcessors)
+        processor->setAsyncProposalAvailable(nullptr);
+    m_runningAssistProcessors.clear();
     return true;
 }
 

src/plugins/languageclient/client.h

@@ -59,6 +59,7 @@ namespace Core { class IDocument; }
 namespace ProjectExplorer { class Project; }
 namespace TextEditor
 {
+class IAssistProcessor;
 class TextDocument;
 class TextEditorWidget;
 class TextMark;
@@ -141,6 +142,9 @@ public:
     bool isSupportedFile(const Utils::FilePath &filePath, const QString &mimeType) const;
     bool isSupportedUri(const LanguageServerProtocol::DocumentUri &uri) const;
 
+    void addAssistProcessor(TextEditor::IAssistProcessor *processor);
+    void removeAssistProcessor(TextEditor::IAssistProcessor *processor);
+
     void setName(const QString &name) { m_displayName = name; }
     QString name() const { return m_displayName; }
 
@@ -233,6 +237,7 @@ private:
     HoverHandler m_hoverHandler;
     QHash<LanguageServerProtocol::DocumentUri, TextEditor::HighlightingResults> m_highlights;
     const ProjectExplorer::Project *m_project = nullptr;
+    QSet<TextEditor::IAssistProcessor *> m_runningAssistProcessors;
 };
 
 } // namespace LanguageClient

src/plugins/languageclient/languageclientcompletionassist.cpp

@@ -342,6 +342,7 @@ IAssistProposal *LanguageClientCompletionAssistProcessor::perform(const AssistIn
     });
     completionRequest.setParams(params);
     m_client->sendContent(completionRequest);
+    m_client->addAssistProcessor(this);
     m_currentRequest = completionRequest.id();
     m_document = interface->textDocument();
     qCDebug(LOGLSPCOMPLETION) << QTime::currentTime()
@@ -359,6 +360,7 @@ void LanguageClientCompletionAssistProcessor::cancel()
 {
     if (running()) {
         m_client->cancelRequest(m_currentRequest);
+        m_client->removeAssistProcessor(this);
         m_currentRequest = MessageId();
     }
 }
@@ -376,6 +378,7 @@ void LanguageClientCompletionAssistProcessor::handleCompletionResponse(
     const Utils::optional<CompletionResult> &result = response.result();
     if (!result || Utils::holds_alternative<std::nullptr_t>(*result)) {
         setAsyncProposalAvailable(nullptr);
+        m_client->removeAssistProcessor(this);
         return;
     }
 
@@ -396,6 +399,7 @@ void LanguageClientCompletionAssistProcessor::handleCompletionResponse(
     proposal->setFragile(true);
     proposal->setSupportsPrefix(false);
     setAsyncProposalAvailable(proposal);
+    m_client->removeAssistProcessor(this);
     qCDebug(LOGLSPCOMPLETION) << QTime::currentTime() << " : "
                               << items.count() << " completions handled";
 }

src/plugins/languageclient/languageclientfunctionhint.cpp

@@ -96,6 +96,7 @@ void FunctionHintProcessor::cancel()
 {
     if (running()) {
         m_client->cancelRequest(m_currentRequest);
+        m_client->removeAssistProcessor(this);
         m_currentRequest = MessageId();
     }
 }
@@ -107,6 +108,7 @@ void FunctionHintProcessor::handleSignatureResponse(const SignatureHelpRequest::
         m_client->log(error.value());
     FunctionHintProposalModelPtr model(
         new FunctionHintProposalModel(response.result().value().value()));
+    m_client->removeAssistProcessor(this);
     setAsyncProposalAvailable(new FunctionHintProposal(m_pos, model));
 }
 

src/plugins/languageclient/languageclientquickfix.cpp

@@ -132,6 +132,7 @@ void LanguageClientQuickFixAssistProcessor::cancel()
 {
     if (running()) {
         m_client->cancelRequest(m_currentRequest);
+        m_client->removeAssistProcessor(this);
         m_currentRequest = MessageId();
     }
 }
@@ -154,6 +155,7 @@ void LanguageClientQuickFixAssistProcessor::handleCodeActionResponse(
             }
         }
     }
+    m_client->removeAssistProcessor(this);
     setAsyncProposalAvailable(GenericProposal::createProposal(m_assistInterface.data(), ops));
 }
 

src/plugins/texteditor/codeassist/codeassistant.cpp

@@ -252,8 +252,9 @@ void CodeAssistantPrivate::requestProposal(AssistReason reason,
         break;
     }
     case IAssistProvider::Asynchronous: {
-        processor->setAsyncCompletionAvailableHandler(
+        processor->setAsyncCompletionAvailableHandler([this, reason](IAssistProposal *newProposal) {
-            [this, reason](IAssistProposal *newProposal){
+            // do not delete this processor directly since this function is called from within the processor
+            QTimer::singleShot(0, [processor = m_asyncProcessor]() { delete processor; });
                 if (m_asyncProcessor && m_asyncProcessor->needsRestart() && m_receivedContentWhileWaiting) {
                     delete newProposal;
                     m_receivedContentWhileWaiting = false;
@@ -288,8 +289,10 @@ void CodeAssistantPrivate::cancelCurrentRequest()
         m_requestRunner->setDiscardProposal(true);
         disconnect(m_runnerConnection);
     }
-    if (m_asyncProcessor)
+    if (m_asyncProcessor) {
         m_asyncProcessor->cancel();
+        m_asyncProcessor->setAsyncProposalAvailable(nullptr);
+    }
     invalidateCurrentRequestData();
 }