LauncherInterface: Wait for graceful finish of process launcher

Give process launcher a chance to finish its processes
gracefully before we finish process launcher's process in Creator.
Otherwise, when Creator's process reaper kills the process
launcher's process while the process launcher is still
reaping its processes, the process launcher may leave zombies.

Instantiate the ProcessReaper inside ProcessReaper::reap(),
otherwise its destructor won't run at all inside process launcher.

Reverts e45e16d904

Fixes: QTCREATORBUG-27118
Change-Id: I00290cda05538b5a7ecbeb08240d1e3772d43d62
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/launcherinterface.cpp

@@ -138,12 +138,11 @@ void LauncherInterfacePrivate::doStart()
 void LauncherInterfacePrivate::doStop()
 {
     m_server->close();
-    if (!m_process)
-        return;
-    m_process->disconnect();
+    QTC_ASSERT(m_process, return);
     m_socket->shutdown();
-    m_process->waitForFinished(3000);
-    ProcessReaper::reap(m_process);
+    m_process->waitForFinished(-1); // Let the process interface finish so that it finishes
+                                    // reaping any possible processes it has started.
+    delete m_process;
     m_process = nullptr;
 }
 

src/libs/utils/processreaper.cpp

@@ -195,6 +195,7 @@ void ProcessReaper::reap(QProcess *process, int timeoutMs)
         return;
     }
 
+    ProcessReaper::instance();
     new Internal::Reaper(process, timeoutMs);
 }
 

src/plugins/android/androiddevice.cpp

@@ -35,8 +35,6 @@
 
 #include <coreplugin/icore.h>
 
-#include <extensionsystem/iplugin.h>
-
 #include <projectexplorer/devicesupport/devicemanager.h>
 #include <projectexplorer/devicesupport/idevicewidget.h>
 #include <projectexplorer/kitinformation.h>
@@ -621,28 +619,6 @@ void AndroidDeviceManager::setupDevicesWatcher()
     updateAvdsList();
 }
 
-void AndroidDeviceManager::shutdownDevicesWatcher()
-{
-    m_avdsFutureWatcher.waitForFinished();
-    m_removeAvdFutureWatcher.waitForFinished();
-
-    if (m_adbDeviceWatcherProcess) {
-        m_adbDeviceWatcherProcess->terminate();
-        m_adbDeviceWatcherProcess->waitForFinished();
-        m_adbDeviceWatcherProcess.reset();
-
-        // Despite terminate/waitForFinished, the process may still
-        // be around and remain if Qt Creator finishes too early.
-        QTimer::singleShot(1000, this, [this] { emit devicesWatcherShutdownFinished(); });
-    }
-}
-
-ExtensionSystem::IPlugin::ShutdownFlag AndroidDeviceManager::devicesShutdownFlag() const
-{
-    return m_adbDeviceWatcherProcess ? ExtensionSystem::IPlugin::AsynchronousShutdown
-                                     : ExtensionSystem::IPlugin::SynchronousShutdown;
-}
-
 void AndroidDeviceManager::HandleAvdsListChange()
 {
     DeviceManager *const devMgr = DeviceManager::instance();
@@ -706,6 +682,13 @@ void AndroidDeviceManager::HandleAvdsListChange()
     }
 }
 
+void AndroidDeviceManager::shutdownDevicesWatcher()
+{
+    m_avdsFutureWatcher.waitForFinished();
+    m_removeAvdFutureWatcher.waitForFinished();
+    m_adbDeviceWatcherProcess.reset();
+}
+
 void AndroidDeviceManager::HandleDevicesListChange(const QString &serialNumber)
 {
     DeviceManager *const devMgr = DeviceManager::instance();

src/plugins/android/androiddevice.h

@@ -30,8 +30,6 @@
 #include "androidconfigurations.h"
 #include "androiddeviceinfo.h"
 
-#include <extensionsystem/iplugin.h>
-
 #include <projectexplorer/devicesupport/idevice.h>
 #include <projectexplorer/devicesupport/idevicefactory.h>
 
@@ -106,7 +104,7 @@ public:
     static AndroidDeviceManager *instance();
     void setupDevicesWatcher();
     void shutdownDevicesWatcher();
-    ExtensionSystem::IPlugin::ShutdownFlag devicesShutdownFlag() const;
+
     void updateAvdsList();
     IDevice::DeviceState getDeviceState(const QString &serial, IDevice::MachineType type) const;
     void updateDeviceState(const ProjectExplorer::IDevice::ConstPtr &device);
@@ -118,9 +116,6 @@ public:
 
     QString getRunningAvdsSerialNumber(const QString &name) const;
 
-signals:
-    void devicesWatcherShutdownFinished();
-
 private:
     AndroidDeviceManager(QObject *parent = nullptr);
     void HandleDevicesListChange(const QString &serialNumber);

src/plugins/android/androidplugin.cpp

@@ -160,17 +160,10 @@ bool AndroidPlugin::initialize(const QStringList &arguments, QString *errorMessa
     return true;
 }
 
-AndroidPlugin::ShutdownFlag AndroidPlugin::aboutToShutdown()
+ExtensionSystem::IPlugin::ShutdownFlag AndroidPlugin::aboutToShutdown()
 {
-    AndroidDeviceManager *dm = AndroidDeviceManager::instance();
-    const IPlugin::ShutdownFlag sf = dm->devicesShutdownFlag();
-
-    if (sf == AsynchronousShutdown)
-        connect(dm, &AndroidDeviceManager::devicesWatcherShutdownFinished,
-                this, &ExtensionSystem::IPlugin::asynchronousShutdownFinished);
-
-    dm->shutdownDevicesWatcher();
-    return sf;
+    AndroidDeviceManager::instance()->shutdownDevicesWatcher();
+    return ExtensionSystem::IPlugin::SynchronousShutdown;
 }
 
 void AndroidPlugin::kitsRestored()

src/plugins/android/androidplugin.h

@@ -44,9 +44,7 @@ class AndroidPlugin final : public ExtensionSystem::IPlugin
 
     class AndroidPluginPrivate *d = nullptr;
 
-public:
     ShutdownFlag aboutToShutdown() final;
-
 #ifdef WITH_TESTS
 private slots:
    void testAndroidSdkManagerProgressParser_data();