QThread: terminate on exceptions leaving run()

Align ourselves to the Standard Library and call std::terminate if an
exception leaves the thread entry point (that is, run()).

On platforms using pthreads, thread cancellation needs to be taken in
special consideration, since it looks like it was supported before.

On Glibc, and when using C++, pthread_cancel and pthread_exit are
implemented by throwing a special kind of exception that can be caught,
but must always be rethrown. That exception is then used to activate the
cancellation clean-up handlers. (This is non-Standard C++ behavior.)

So: mimic what libstdc++'s std::thread does to support Glibc's pthread
cancellation.

At this time, it looks like libc++ has no support for this, and when
used in combination with Glibc a thread cancellation results in a crash
(also because it does not seem to terminate() when exceptions leave the
thread).

[ChangeLog][QtCore][QThread] An exception escaping from QThread::run()
will now result in immediate and abnormal program termination. The same
applies if an exception leaves a slot connected directly to the
QThread::started() or QThread::finished() signals.

Change-Id: I73cc93cf06c57018e149a578cc9d4cd0d6fc00ef
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/corelib/thread/qthread_p.h b/src/corelib/thread/qthread_p.h
index 885b4c0c1e..f3d4750177 100644
--- a/src/corelib/thread/qthread_p.h
+++ b/src/corelib/thread/qthread_p.h
@@ -184,8 +184,8 @@ public:
 #endif // Q_OS_UNIX
 
 #ifdef Q_OS_WIN
-    static unsigned int __stdcall start(void *);
-    static void finish(void *, bool lockAnyway=true);
+    static unsigned int __stdcall start(void *) Q_DECL_NOEXCEPT;
+    static void finish(void *, bool lockAnyway=true) Q_DECL_NOEXCEPT;
 
     Qt::HANDLE handle;
     unsigned int id;