In the constructor, we create a thread and worker instance. Notice that the worker does not receive a parent, because it will be moved to the new thread. Because of this, Qt won’t be able to release the worker’s memory automatically, and therefore, we need to do this by connecting QThread::finished signal to deleteLater slot. Qt Performance vs MFC Performance - Google Groups signal/slot performance, you need to take into account whether the slot is run on the same thread as the signal is emitted, because if it is the same thread, it resolves to a simple function call, but if it is a different thread, the parameters must be marshaled to the other thread and the slot Multithreaded programming for multicore architectures with Qt ...
Signals and Slots in Depth | C++ GUI Programming with Qt…
Application Performance Management; ... Qt provides thread support in the form of platform-independent threading classes, a thread-safe way of posting events, and signal-slot connections across ... Signals and slots - Wikipedia Signals and slots is a language construct introduced in Qt for communication between objects which makes it easy to implement the observer pattern while avoiding boilerplate code. The concept is that GUI widgets can send signals containing event information which can be received by other widgets / controls using special functions known as slots ... Signals and Slots in Depth | C++ GUI Programming with Qt4 ...
It depends on what each thread does. Rule of thumb: for CPU bound threads more threads than cores will decrease overall performance; for I/O bound threads it is possible to have more threads than available cores. You need to measure. – Richard Critten Jun 6 '15 at 7:55
Synchronizing Threads | Qt 5.12 To place an invocation in an event loop, make a queued signal-slot connection. Whenever the signal is emitted, its arguments will be recorded by the event system. The thread that the signal receiver lives in will then run the slot. Alternatively, call QMetaObject::invokeMethod() to achieve the same effect without signals. c++ - Multithreading performance of QtConcurrent Vs
Threads and QObjects | Qt 4.8
C++ Qt 122 - QtConcurrent Run a thread with signals and ... These videos are a bit outdated - I am in the process of replacing these with courses on Udemy.com Below are links for the courses I have finished so far. (I will be making much much more) Qt Core ...
Qt: Signal/Slot not working after QObject moved to different…
As you might have seen in the previous example, the slot was just declared as public and not as slot. Qt will indeed call directly the function pointer of the slot, and will not need moc introspection anymore. (It still needs it for the signal) But what we can also do is connecting to any function or functor: Welcome to the Qt wiki Welcome to the Qt wiki. Here the Qt community has gathered information on Qt over the years. Everything here is created and maintained by the community. Please take a look at the below information before you start contributing.
@Wuzi said in Cannot connect signal and slot from different thread.. Qt::QueuedConnection will be made automatically when I create a connection between two threads or do I have to set it explizit? It is done automatically if you connect after moving to thread. Signal slots across threads performance - Qt Forum when setting up the signal/slot calls to the thread. Reply to Signal slots across threads performance on Tue, 25 Feb 2014 17:43:03 GMT I am using a queued connection because I don't want the caller to perform the necessary computations in the caller's thread. Why I dislike Qt signals/slots - elfery It's possible for the slot/second signal to have fewer arguments than the first. The signals are processed during Qt's event loop and, if the target is in another thread, the arguments are automatically serialized and sent to that thread's event queue. This is very nice to have, as you can imagine. The problem with connections. The issue I have How to Use Signals and Slots - Qt Wiki