Symbian adopted thread monitor review fixes

The adopted thread monitor could cause a stray event panic if multiple
threads where added quickly. A new autotest was written to force the
fault (successfully). A fix was then added.

Task-number: QTBUG-13990
Reviewed-by: Shane Kearns

2 files changed, 48 insertions, 4 deletions

diff --git a/src/corelib/thread/qthread_symbian.cpp b/src/corelib/thread/qthread_symbian.cpp
index 4bbf5e3..096cd6d 100644
--- a/src/corelib/thread/qthread_symbian.cpp
+++ b/src/corelib/thread/qthread_symbian.cpp
@@ -161,13 +161,13 @@ public:
     }
     void DoCancel()
     {
-        TRequestStatus *stat = &iStatus;
         User::RequestComplete(stat, KErrCancel);
     }
     void start()
     {
         iStatus = KRequestPending;
         SetActive();
+        stat = &iStatus;
     }
     void RunL()
     {
@@ -195,9 +195,8 @@ public:
             monitorThread.Close();
         }
         adoptedThreadAdder->threadsToAdd.push_back(thread);
-        if (adoptedThreadAdder->IsActive()) {
-            TRequestStatus *stat = &adoptedThreadAdder->iStatus;
-            adoptedThreadAdder->monitorThread.RequestComplete(stat, KErrNone);
+        if (adoptedThreadAdder->stat) {
+            adoptedThreadAdder->monitorThread.RequestComplete(adoptedThreadAdder->stat, KErrNone);
         }
     }
     static void monitorThreadFuncL()
@@ -232,6 +231,7 @@ private:
     RThread monitorThread;
     static QMutex adoptedThreadMonitorMutex;
     static QCAddAdoptedThread* adoptedThreadAdder;
+    TRequestStatus *stat;
 };
 
 QMutex QCAddAdoptedThread::adoptedThreadMonitorMutex;
diff --git a/tests/auto/qthread/tst_qthread.cpp b/tests/auto/qthread/tst_qthread.cpp
index 1629b91..ee498cc 100644
--- a/tests/auto/qthread/tst_qthread.cpp
+++ b/tests/auto/qthread/tst_qthread.cpp
@@ -104,6 +104,7 @@ private slots:
     void adoptedThreadExec();
     void adoptedThreadFinished();
     void adoptMultipleThreads();
+    void adoptMultipleThreadsOverlap();
 
     void QTBUG13810_exitAndStart();
     void QTBUG15378_exitAndExec();
@@ -947,6 +948,49 @@ void tst_QThread::adoptMultipleThreads()
     QCOMPARE(int(recorder.activationCount), numThreads);
 }
 
+void tst_QThread::adoptMultipleThreadsOverlap()
+{
+#if defined(Q_OS_WIN)
+    // Windows CE is not capable of handling that many threads. On the emulator it is dead with 26 threads already.
+#  if defined(Q_OS_WINCE)
+    const int numThreads = 20;
+#  else
+    // need to test lots of threads, so that we exceed MAXIMUM_WAIT_OBJECTS in qt_adopted_thread_watcher()
+    const int numThreads = 200;
+#  endif
+#elif defined(Q_OS_SYMBIAN)
+    // stress the monitoring thread's add function
+    const int numThreads = 100;
+#else
+    const int numThreads = 5;
+#endif
+    QVector<NativeThreadWrapper*> nativeThreads;
+
+    SignalRecorder recorder;
+
+    for (int i = 0; i < numThreads; ++i) {
+        nativeThreads.append(new NativeThreadWrapper());
+        nativeThreads.at(i)->setWaitForStop();
+        nativeThreads.at(i)->mutex.lock();
+        nativeThreads.at(i)->start();
+    }
+    for (int i = 0; i < numThreads; ++i) {
+        nativeThreads.at(i)->startCondition.wait(&nativeThreads.at(i)->mutex);
+        QObject::connect(nativeThreads.at(i)->qthread, SIGNAL(finished()), &recorder, SLOT(slot()));
+        nativeThreads.at(i)->mutex.unlock();
+    }
+
+    QObject::connect(nativeThreads.at(numThreads - 1)->qthread, SIGNAL(finished()), &QTestEventLoop::instance(), SLOT(exitLoop()));
+
+    for (int i = 0; i < numThreads; ++i) {
+        nativeThreads.at(i)->stop();
+        nativeThreads.at(i)->join();
+    }
+
+    QTestEventLoop::instance().enterLoop(5);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+    QCOMPARE(int(recorder.activationCount), numThreads);
+}
 void tst_QThread::stressTest()
 {
 #if defined(Q_OS_WINCE)