fix occasional hang on exit

We occasionally encountered a hang on exit in ~IoCompletionPort on
QThread::wait().
We must not use Q_GLOBAL_STATIC for IoCompletionPort, because it's a
QThread. We will enter undefined terrain after QCoreApplication is
gone. We now properly destroy IoCompletionPort in ~Application.

Task-number: QTCREATORBUG-14600
Change-Id: I067d50ec6759f5438cf47b2ba01f17a402ab8910
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

5 files changed, 36 insertions, 9 deletions

diff --git a/src/app/application.cpp b/src/app/application.cpp
index a171928..54baedb 100644
--- a/src/app/application.cpp
+++ b/src/app/application.cpp
@@ -19,6 +19,8 @@
  ****************************************************************************/
 
 #include "application.h"
+#include <iocompletionport.h>
+
 #include <QtCore/QDebug>
 #include <QtCore/QFileInfo>
 #include <QtCore/QSet>
@@ -76,6 +78,11 @@ Application::Application(int &argc, char **argv)
     m_bIsSubJOM = NMakeFile::isSubJOM(exeName);
 }
 
+Application::~Application()
+{
+    IoCompletionPort::destroyInstance();
+}
+
 void Application::exit(int exitCode)
 {
     QCoreApplication::exit(exitCode);
diff --git a/src/app/application.h b/src/app/application.h
index 8bb6b26..1b3618b 100644
--- a/src/app/application.h
+++ b/src/app/application.h
@@ -32,6 +32,8 @@ public:
     static Application *instance() { return static_cast<Application*>(QCoreApplication::instance()); }
 
     Application(int &argc, char **argv);
+    ~Application();
+
     const bool isSubJOM() const { return m_bIsSubJOM; }
 
 public slots:
diff --git a/src/jomlib/iocompletionport.cpp b/src/jomlib/iocompletionport.cpp
index 2ea3e88..e2f0d3a 100644
--- a/src/jomlib/iocompletionport.cpp
+++ b/src/jomlib/iocompletionport.cpp
@@ -22,6 +22,8 @@
 
 namespace NMakeFile {
 
+IoCompletionPort *IoCompletionPort::m_instance = 0;
+
 IoCompletionPort::IoCompletionPort()
     : hPort(INVALID_HANDLE_VALUE)
 {
@@ -41,6 +43,19 @@ IoCompletionPort::~IoCompletionPort()
     CloseHandle(hPort);
 }
 
+IoCompletionPort *IoCompletionPort::instance()
+{
+    if (!m_instance)
+        m_instance = new IoCompletionPort;
+    return m_instance;
+}
+
+void IoCompletionPort::destroyInstance()
+{
+    delete m_instance;
+    m_instance = 0;
+}
+
 void IoCompletionPort::registerObserver(IoCompletionPortObserver *observer, HANDLE hFile)
 {
     HANDLE hIOCP = CreateIoCompletionPort(hFile, hPort, reinterpret_cast<ULONG_PTR>(observer), 0);
diff --git a/src/jomlib/iocompletionport.h b/src/jomlib/iocompletionport.h
index 17b44bf..91aea49 100644
--- a/src/jomlib/iocompletionport.h
+++ b/src/jomlib/iocompletionport.h
@@ -37,8 +37,8 @@ public:
 class IoCompletionPort : protected QThread
 {
 public:
-    IoCompletionPort();
-    ~IoCompletionPort();
+    static IoCompletionPort *instance();
+    static void destroyInstance();
 
     void registerObserver(IoCompletionPortObserver *notifier, HANDLE hFile);
     void unregisterObserver(IoCompletionPortObserver *notifier);
@@ -47,6 +47,10 @@ protected:
     void run();
 
 private:
+    IoCompletionPort();
+    ~IoCompletionPort();
+
+    static IoCompletionPort *m_instance;
     HANDLE hPort;
     QSet<IoCompletionPortObserver *> observers;
     QMutex mutex;
diff --git a/src/jomlib/process.cpp b/src/jomlib/process.cpp
index 5332c22..224bf9a 100644
--- a/src/jomlib/process.cpp
+++ b/src/jomlib/process.cpp
@@ -47,7 +47,6 @@
 
 namespace NMakeFile {
 
-Q_GLOBAL_STATIC(IoCompletionPort, iocp)
 Q_GLOBAL_STATIC(QElapsedTimer, runtime)
 
 struct Pipe
@@ -161,8 +160,8 @@ Process::Process(QObject *parent)
 
 Process::~Process()
 {
-    iocp()->unregisterObserver(&d->stdoutChannel);
-    iocp()->unregisterObserver(&d->stderrChannel);
+    IoCompletionPort::instance()->unregisterObserver(&d->stdoutChannel);
+    IoCompletionPort::instance()->unregisterObserver(&d->stderrChannel);
 
     if (m_state == Running)
         qWarning("Process: destroyed while process still running.");
@@ -362,8 +361,8 @@ void Process::start(const QString &commandLine)
     if (!setupPipe(d->stderrPipe, &sa, OutputPipe))
         qFatal("Cannot setup pipe for stderr.");
 
-    iocp()->registerObserver(&d->stdoutChannel, d->stdoutPipe.hRead);
-    iocp()->registerObserver(&d->stderrChannel, d->stderrPipe.hRead);
+    IoCompletionPort::instance()->registerObserver(&d->stdoutChannel, d->stdoutPipe.hRead);
+    IoCompletionPort::instance()->registerObserver(&d->stderrChannel, d->stderrPipe.hRead);
     if (!d->startRead()) {
         m_state = NotRunning;
         emit error(FailedToStart);
@@ -429,8 +428,8 @@ void Process::onProcessFinished()
         return;
 
     d->deathNotifier.setEnabled(false);
-    iocp()->unregisterObserver(&d->stdoutChannel);
-    iocp()->unregisterObserver(&d->stderrChannel);
+    IoCompletionPort::instance()->unregisterObserver(&d->stdoutChannel);
+    IoCompletionPort::instance()->unregisterObserver(&d->stderrChannel);
     safelyCloseHandle(d->stdoutPipe.hRead);
     safelyCloseHandle(d->stderrPipe.hRead);
     safelyCloseHandle(d->hProcess);