Python: Don't leak running futures on shutdown

This patch fixes the following assert on shutdown:
"Shutting down while process /testenv/bin/python is running\"\n".

Change-Id: I4c32ead5e4952b69ffc6037739fd417a632eda1a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/python/pythonplugin.cpp

@@ -16,9 +16,11 @@
 #include <projectexplorer/taskhub.h>
 
 #include <utils/fsengine/fileiconprovider.h>
+#include <utils/futuresynchronizer.h>
 #include <utils/theme/theme.h>
 
 using namespace ProjectExplorer;
+using namespace Utils;
 
 namespace Python::Internal {
 
@@ -34,6 +36,7 @@ public:
     PySideBuildConfigurationFactory buildConfigFactory;
     SimpleTargetRunnerFactory runWorkerFactory{{runConfigFactory.runConfigurationId()}};
     PythonSettings settings;
+    FutureSynchronizer m_futureSynchronizer;
 };
 
 PythonPlugin::PythonPlugin()
@@ -52,6 +55,12 @@ PythonPlugin *PythonPlugin::instance()
     return m_instance;
 }
 
+FutureSynchronizer *PythonPlugin::futureSynchronizer()
+{
+    QTC_ASSERT(m_instance, return nullptr);
+    return &m_instance->d->m_futureSynchronizer;
+}
+
 void PythonPlugin::initialize()
 {
     d = new PythonPluginPrivate;
@@ -62,9 +71,9 @@ void PythonPlugin::initialize()
 void PythonPlugin::extensionsInitialized()
 {
     // Add MIME overlay icons (these icons displayed at Project dock panel)
-    QString imageFile = Utils::creatorTheme()->imageFile(Utils::Theme::IconOverlayPro,
-                                                         ::Constants::FILEOVERLAY_PY);
-    Utils::FileIconProvider::registerIconOverlayForSuffix(imageFile, "py");
+    const QString imageFile = Utils::creatorTheme()->imageFile(Theme::IconOverlayPro,
+                                                               ::Constants::FILEOVERLAY_PY);
+    FileIconProvider::registerIconOverlayForSuffix(imageFile, "py");
 
     TaskHub::addCategory(PythonErrorTaskCategory, "Python", true);
 }

src/plugins/python/pythonplugin.h

@@ -5,6 +5,8 @@
 
 #include <extensionsystem/iplugin.h>
 
+namespace Utils { class FutureSynchronizer; }
+
 namespace Python::Internal {
 
 class PythonPlugin final : public ExtensionSystem::IPlugin
@@ -17,6 +19,7 @@ public:
     ~PythonPlugin() final;
 
     static PythonPlugin *instance();
+    static Utils::FutureSynchronizer *futureSynchronizer();
 
 private:
     void initialize() final;

src/plugins/python/pythonrunconfiguration.cpp

@@ -9,6 +9,7 @@
 #include "pysideuicextracompiler.h"
 #include "pythonconstants.h"
 #include "pythonlanguageclient.h"
+#include "pythonplugin.h"
 #include "pythonproject.h"
 #include "pythonsettings.h"
 #include "pythontr.h"
@@ -31,6 +32,7 @@
 
 #include <utils/aspects.h>
 #include <utils/fileutils.h>
+#include <utils/futuresynchronizer.h>
 #include <utils/layoutbuilder.h>
 #include <utils/outputformatter.h>
 #include <utils/theme/theme.h>
@@ -241,15 +243,12 @@ void PythonRunConfigurationPrivate::checkForPySide(const FilePath &python,
 {
     const PipPackage package(pySidePackageName);
     QObject::disconnect(m_watcherConnection);
-    m_watcherConnection = QObject::connect(&m_watcher,
-                                           &QFutureWatcher<PipPackageInfo>::finished,
-                                           q,
-                                           [=]() {
-                                               handlePySidePackageInfo(m_watcher.result(),
-                                                                       python,
-                                                                       pySidePackageName);
-                                           });
-    m_watcher.setFuture(Pip::instance(python)->info(package));
+    m_watcherConnection = QObject::connect(&m_watcher, &QFutureWatcherBase::finished, q, [=] {
+        handlePySidePackageInfo(m_watcher.result(), python, pySidePackageName);
+    });
+    const auto future = Pip::instance(python)->info(package);
+    m_watcher.setFuture(future);
+    PythonPlugin::futureSynchronizer()->addFuture(future);
 }
 
 void PythonRunConfigurationPrivate::handlePySidePackageInfo(const PipPackageInfo &pySideInfo,