Removing potential crashes from out-of-thread cleanup on Symbian

There have been some crashes seen on Symbian when its
adoptedThreadMonitor attempts to clean up objects created in other, now
dead, threads. Some of these objects simply can't be cleaned up
properly outside of their original thread, so the thread has to be
checked when they are cleaned up, and cleanup skipped in the wrong
thread.

For pthread created threads, we also have the ability to insert cleanup
code during thread shutdown. This was used in the 4.7 implementation of
QThread on Symbian, and is a better solution for pthread based adopted
threads as it gives in-thread cleanup. So the appropriate pthread code
is also used with changes to adoptedThreadMonitor so that it can run
along side the pthread cleanup code.

Change-Id: Iad8207879b1ece62e5cce85f26a616166aa22486
Reviewed-by: Juha Kukkonen <ext-juha.kukkonen@nokia.com>
Reviewed-by: Pasi Pentikäinen <ext-pasi.a.pentikainen@nokia.com>

1 files changed, 35 insertions, 3 deletions

diff --git a/src/corelib/thread/qthread_symbian.cpp b/src/corelib/thread/qthread_symbian.cpp
index 149da9c3b8..e5246619aa 100644
--- a/src/corelib/thread/qthread_symbian.cpp
+++ b/src/corelib/thread/qthread_symbian.cpp
@@ -264,26 +264,58 @@ private:
 QMutex QCAddAdoptedThread::adoptedThreadMonitorMutex;
 QCAddAdoptedThread* QCAddAdoptedThread::adoptedThreadAdder = 0;
 
-void QCAdoptedThreadMonitor::RunL()
+static void finishAdoptedThread(QThreadData* data, bool closeNativeHandle)
 {
     if (data->isAdopted) {
         QThread *thread = data->thread;
         Q_ASSERT(thread);
         QThreadPrivate *thread_p = static_cast<QThreadPrivate *>(QObjectPrivate::get(thread));
-        Q_ASSERT(!thread_p->finished);
-        thread_p->finish(thread);
+        if (!thread_p->finished)
+            thread_p->finish(thread, true, closeNativeHandle);
+        else if (closeNativeHandle && data->symbian_thread_handle.Handle())
+            data->symbian_thread_handle.Close();
     }
+}
+
+void QCAdoptedThreadMonitor::RunL()
+{
+    // clean up the thread, or close the handle if that's all that's left
+    finishAdoptedThread(data, true);
     data->deref();
     QCAddAdoptedThread::threadDied();
     delete this;
 }
 
+static pthread_once_t current_thread_data_once = PTHREAD_ONCE_INIT;
+static pthread_key_t current_thread_data_key;
+
+static void pthread_in_thread_cleanup(void *p)
+{
+    QThreadData *data = static_cast<QThreadData *>(p);
+    // clean up the thread, but leave the handle for adoptedThreadMonitor
+    finishAdoptedThread(data, false);
+}
+
+static void create_current_thread_data_key()
+{
+    pthread_key_create(&current_thread_data_key, pthread_in_thread_cleanup);
+}
+
+static void destroy_current_thread_data_key()
+{
+    pthread_once(&current_thread_data_once, create_current_thread_data_key);
+    pthread_key_delete(current_thread_data_key);
+}
+Q_DESTRUCTOR_FUNCTION(destroy_current_thread_data_key)
+
 void QAdoptedThread::init()
 {
     Q_D(QThread);
     d->thread_id = RThread().Id();  // type operator to TUint
     init_symbian_thread_handle(d->data->symbian_thread_handle);
     QCAddAdoptedThread::add(this);
+    pthread_once(&current_thread_data_once, create_current_thread_data_key);
+    pthread_setspecific(current_thread_data_key, get_thread_data());
 }
 
 /*