From 5ef4530b8f30e3f33381292ef45fb0b358efcadc Mon Sep 17 00:00:00 2001
From: David Schulz <david.schulz@qt.io>
Date: Thu, 13 Sep 2018 15:31:00 +0200
Subject: [PATCH] LSP: use asynchronous shutdown for running servers

Change-Id: I3b1853177d07c98e051de0bc9f494389fbf4c104
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
---
 .../languageclient/languageclientmanager.cpp  | 33 +++++++++++++++----
 .../languageclient/languageclientmanager.h    |  8 +++++
 .../languageclient/languageclientplugin.cpp   | 12 +++++++
 .../languageclient/languageclientplugin.h     |  1 +
 4 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/src/plugins/languageclient/languageclientmanager.cpp b/src/plugins/languageclient/languageclientmanager.cpp
index c8f7b97f550..c96fa2e1ef0 100644
--- a/src/plugins/languageclient/languageclientmanager.cpp
+++ b/src/plugins/languageclient/languageclientmanager.cpp
@@ -82,8 +82,7 @@ LanguageClientManager::LanguageClientManager()
 
 LanguageClientManager::~LanguageClientManager()
 {
-    for (auto interface : Utils::filtered(m_clients, &BaseClient::reachable))
-        interface->shutdown();
+    QTC_ASSERT(m_clients.isEmpty(), qDeleteAll(m_clients));
 }
 
 void LanguageClientManager::init()
@@ -168,6 +167,8 @@ void LanguageClientManager::removeMarks(const Core::Id &id)
 
 void LanguageClientManager::startClient(LanguageClientSettings setting)
 {
+    if (managerInstance->m_shuttingDown)
+        return;
     auto client = new StdIOClient(setting.m_executable, setting.m_arguments);
     client->setName(setting.m_name);
     if (setting.m_mimeType != noLanguageFilter)
@@ -177,6 +178,10 @@ void LanguageClientManager::startClient(LanguageClientSettings setting)
 
 void LanguageClientManager::startClient(BaseClient *client)
 {
+    if (managerInstance->m_shuttingDown) {
+        managerInstance->clientFinished(client);
+        return;
+    }
     if (!managerInstance->m_clients.contains(client))
         managerInstance->m_clients.append(client);
     connect(client, &BaseClient::finished, managerInstance, [client](){
@@ -215,6 +220,20 @@ void LanguageClientManager::deleteClient(BaseClient *client)
     delete client;
 }
 
+void LanguageClientManager::shutdown()
+{
+    if (managerInstance->m_shuttingDown)
+        return;
+    managerInstance->m_shuttingDown = true;
+    for (auto interface : managerInstance->m_clients)
+        interface->shutdown();
+}
+
+LanguageClientManager *LanguageClientManager::instance()
+{
+    return managerInstance;
+}
+
 QVector<BaseClient *> LanguageClientManager::reachableClients()
 {
     return Utils::filtered(m_clients, &BaseClient::reachable);
@@ -236,15 +255,17 @@ void LanguageClientManager::clientFinished(BaseClient *client)
     constexpr int restartTimeoutS = 5;
     const bool unexpectedFinish = client->state() != BaseClient::Shutdown
             && client->state() != BaseClient::ShutdownRequested;
-    if (unexpectedFinish) {
-        managerInstance->removeMarks(client->id());
-        client->disconnect(managerInstance);
+    if (unexpectedFinish && !m_shuttingDown) {
+        removeMarks(client->id());
+        client->disconnect(this);
         client->log(tr("Unexpectedly finished. Restarting in %1 seconds.").arg(restartTimeoutS),
                     Core::MessageManager::Flash);
         client->reset();
-        QTimer::singleShot(restartTimeoutS * 1000, this, [client](){ startClient(client); });
+        QTimer::singleShot(restartTimeoutS * 1000, client, [client](){ startClient(client); });
     } else {
         deleteClient(client);
+        if (m_shuttingDown && m_clients.isEmpty())
+            emit shutdownFinished();
     }
 }
 
diff --git a/src/plugins/languageclient/languageclientmanager.h b/src/plugins/languageclient/languageclientmanager.h
index a00c86858ed..b15deca0f6a 100644
--- a/src/plugins/languageclient/languageclientmanager.h
+++ b/src/plugins/languageclient/languageclientmanager.h
@@ -70,6 +70,13 @@ public:
 
     static void deleteClient(BaseClient *client);
 
+    static void shutdown();
+
+    static LanguageClientManager *instance();
+
+signals:
+    void shutdownFinished();
+
 private:
     LanguageClientManager();
     LanguageClientManager(const LanguageClientManager &other) = delete;
@@ -90,6 +97,7 @@ private:
 
     void clientFinished(BaseClient *client);
 
+    bool m_shuttingDown = false;
     QVector<BaseClient *> m_clients;
     QHash<Utils::FileName, QHash<Core::Id, QVector<LanguageClientMark *>>> m_marks;
     QHash<LanguageServerProtocol::MessageId, QList<BaseClient *>> m_exclusiveRequests;
diff --git a/src/plugins/languageclient/languageclientplugin.cpp b/src/plugins/languageclient/languageclientplugin.cpp
index 4fd3cedfcf8..53a0252592a 100644
--- a/src/plugins/languageclient/languageclientplugin.cpp
+++ b/src/plugins/languageclient/languageclientplugin.cpp
@@ -25,6 +25,8 @@
 
 #include "languageclientplugin.h"
 
+#include "baseclient.h"
+
 namespace LanguageClient {
 
 bool LanguageClientPlugin::initialize(const QStringList & /*arguments*/, QString * /*errorString*/)
@@ -38,4 +40,14 @@ void LanguageClientPlugin::extensionsInitialized()
     LanguageClientSettings::init();
 }
 
+ExtensionSystem::IPlugin::ShutdownFlag LanguageClientPlugin::aboutToShutdown()
+{
+    LanguageClientManager::shutdown();
+    if (LanguageClientManager::clients().isEmpty())
+        return ExtensionSystem::IPlugin::SynchronousShutdown;
+    connect(LanguageClientManager::instance(), &LanguageClientManager::shutdownFinished,
+            this, &ExtensionSystem::IPlugin::asynchronousShutdownFinished);
+    return ExtensionSystem::IPlugin::AsynchronousShutdown;
+}
+
 } // namespace LanguageClient
diff --git a/src/plugins/languageclient/languageclientplugin.h b/src/plugins/languageclient/languageclientplugin.h
index 31a4c1ae99b..5b34c049a7e 100644
--- a/src/plugins/languageclient/languageclientplugin.h
+++ b/src/plugins/languageclient/languageclientplugin.h
@@ -43,6 +43,7 @@ public:
 private:
     bool initialize(const QStringList &arguments, QString *errorString) override;
     void extensionsInitialized() override;
+    ShutdownFlag aboutToShutdown() override;
 
 private:
     LanguageClientManager m_clientManager;