QObject creating in one thread using in other
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hi,
is it possible to create a QObject derived classes and connect the signals in a different thread.
The QObject loads a plugin in side it. When i try to access the QObject variables in the other thread after releasing the locks on the object, the application is crashing.
-Sriky
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Hm, maybe you can provide some sources for better explanation?
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Passing signals back and forth between threads is thread save, accessing member variables of an object from another thread is not. So your application behaves exactly as expected.
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Tobias, but simple reading member (without any operatinos from other threads on it) of object from another thread should not crash app.
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[quote author="Denis Kormalev" date="1287682429"]Tobias, but simple reading member (without any operatinos from other threads on it) of object from another thread should not crash app.[/quote]
You can you a QMutex to solve the writing part, afair...
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danilocesar, it is part what I am saying of. As I think author doesn't have race conditions, but has some problems with accessing members. So I think source will be really good to help him.
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Denis: Sure, but how do you guarantee that no other thread does some writing somewhere without using a mutex or something similar?
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[quote author="Tobias Hunger" date="1287687383"]Denis: Sure, but how do you guarantee that no other thread does some writing somewhere without using a mutex or something similar?[/quote]
You don't, however you need to understand/know what your code is doing =)
I believe we will help better when sriky27 post some code...
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Tobias, of course there are no guarantee, but I think that question is not about mutexes. Let's wait for authors response.
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[quote author="Tobias Hunger" date="1287687383"]Denis: Sure, but how do you guarantee that no other thread does some writing somewhere without using a mutex or something similar?[/quote]
I thought this message was for me =/
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Hi,
Thanks for the responses there I am currently stripping my project related content and creating a simple application to present here. To explain what I am doing.
My objective of creating and starting a new thread was to improve startup of my process, the thread purely constructs an QObject and returns it to the main thread. The thread dies after that.
I believe I should not have any race conditions there. No one else is trying to access the object.-Sriky
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A commonly used trick to improved perceived startup performance is to create some objects using a singleshot QTimer. That way the complexity of multithreading can be avoided in some cases. Maybe that would be applicable to your setup, too.
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well i have tried it, i have two objects which take about 2 sec for constructing each of them, i wanted improve on it, so that the objects gets constructed in parallel.
-Sriky