Posting customeEvent using postEvent crashes Windows but works on Ubuntu Linux

[cqubed]

Thanks for the tip, but I've already tested that. In one version of the program I removed QString* and everything else from the event. It still crashes.
Note, in version I posted the QString is allocated on the heap and I delete it in the destructor of my over-riding virtual customEvent method. That delete doesn't crash.
The crash seems to be occurring when the Qt library deletes the event. This crash occurs even if I declare my custom event to be exactly like a standard event.

[wysota]

Note, in version I posted the QString is allocated on the heap and I delete it in the destructor of my over-riding virtual customEvent method.

What if one calls setMsg more than once?

The crash seems to be occurring when the Qt library deletes the event. This crash occurs even if I declare my custom event to be exactly like a standard event.

Please post a minimal compilable example reproducing the problem.

BTW. Isn't your thread accessing the main window subclass?

[cqubed]

What if one calls setMsg more than once?
Please post a minimal compilable example reproducing the problem. BTW. Isn't your thread accessing the main window subclass?

If setMsg is called more than once, application will leak memory, but this won't cause crash.
Is my worker thread accessing main window subclass?

I'll check, but don't think so.

[wysota]

Is my worker thread accessing main window subclass?

It is.

Furthermore if you pass a string pointer to the constructor of the event, it will potentially cause a double delete because you are storing a pointer to the string as-is, without making a copy of the string that you later delete in the destructor.

I suggest you simplify your code as much as possible, then it will be much simpler to find the problem. For instance this:

void writeWin(QString *msg) {
		if (( m_PtrWorkerThread != NULL) && (QThread::currentThread()== m_PtrWorkerThread)) {
			while(m_MustWait) {
	#ifdef WIN32
				Sleep(1);
	#else
				usleep(10);//1,000,000 in sec
	#endif
			}
			{
				m_MustWait =  true;
				m_PtrMsg = msg;
				PostMessageEvent *ptr_msgEvent = new(PostMessageEvent);
				ptr_msgEvent->m_ptrPostingThread=QThread::currentThread();
				ptr_msgEvent->setMsg(msg);
				QCoreApplication::postEvent ( this, ptr_msgEvent);
 
			}
		} else
		{
//			m_MustWait =  true;
			PostMessageEvent *ptr_msgEvent = new(PostMessageEvent);
			ptr_msgEvent->m_ptrPostingThread=QThread::currentThread();
			ptr_msgEvent->setMsg(msg);
			QCoreApplication::postEvent ( this, ptr_msgEvent);
 
		}
	};

void writeWin(QString *msg) {
		if (( m_PtrWorkerThread != NULL) && (QThread::currentThread()== m_PtrWorkerThread)) {
			while(m_MustWait) {
	#ifdef WIN32
				Sleep(1);
	#else
				usleep(10);//1,000,000 in sec
	#endif
			}
			{
				m_MustWait =  true;
				m_PtrMsg = msg;
				PostMessageEvent *ptr_msgEvent = new(PostMessageEvent);
				ptr_msgEvent->m_ptrPostingThread=QThread::currentThread();
				ptr_msgEvent->setMsg(msg);
				QCoreApplication::postEvent ( this, ptr_msgEvent);

			}
		} else
		{
//			m_MustWait =  true;
			PostMessageEvent *ptr_msgEvent = new(PostMessageEvent);
			ptr_msgEvent->m_ptrPostingThread=QThread::currentThread();
			ptr_msgEvent->setMsg(msg);
			QCoreApplication::postEvent ( this, ptr_msgEvent);

		}
	};

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can be written as this (I don't know why you sleep for a couple of seconds here so I ignored that part):

void writeWin(const QString& msg) {
				PostMessageEvent *ptr_msgEvent = new(PostMessageEvent);
				ptr_msgEvent->setMsg(msg);
			        ptr_msgEvent->m_ptrPostingThread=QThread::currentThread(); // optionally, if you really need it
				QCoreApplication::postEvent ( this, ptr_msgEvent);
};

void writeWin(const QString& msg) {
				PostMessageEvent *ptr_msgEvent = new(PostMessageEvent);
				ptr_msgEvent->setMsg(msg);
			        ptr_msgEvent->m_ptrPostingThread=QThread::currentThread(); // optionally, if you really need it
				QCoreApplication::postEvent ( this, ptr_msgEvent);
};

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or better yet just use signals and slots (properly). If you have to "wait", then use a wait condition instead of a busy loop.