Linux Program Development: multi-thread programming in QT

Linux Program Development: multi-thread programming in QT-general Linux technology-Linux programming and kernel information. For details, see the following. As a cross-platform GUI system based on C ++, Qt provides powerful functions for users to construct graphical user interfaces. To meet the user's need to construct a complex graphic interface system, Qt provides rich multi-threaded programming support.

As a cross-platform GUI system based on C ++, Qt provides powerful functions for users to construct graphical user interfaces. To meet the user's need to construct a complex graphic interface system, Qt provides rich multi-threaded programming support. Starting from Version 2.2, Qt provides support for multi-threaded programming in the following three aspects: 1. constructs some basic thread classes unrelated to the platform; ii. Thread-safe mode for submitting user-defined events; iii. Multiple inter-Thread synchronization mechanisms, such as semaphores and global locks. These provide great convenience for users. However, in some cases, using the timer mechanism enables Billy to use the multi-thread mechanism of Qt itself to implement the required functions more conveniently and avoid the occurrence of unsafe phenomena. This article not only discusses the multi-thread support mechanism in Qt, but also focuses on the method of simulating multi-thread programming by using the timer mechanism.

1. multi-thread programming supported by the system

Different platforms support different methods for Qt multithreading. When you install Qt on a Windows operating system, thread support is an option of the compiler. The mkfiles subdirectory of Qt contains the compilation files of different types of compilers, among them, files with the-mt suffix support multithreading.

In Unix operating systems, thread support is added by adding the-thread option when running the configure script file. The installation process creates an independent library, libqt-mt. To support multi-threaded programming, you must connect to the Library (the link option is-lqt-mt ), instead of connecting to the common Qt Library (-lqt.

In addition, regardless of the platform, you must define the macro QT_THREAD_SUPPORT (that is, add the compilation option-DQT_THREAD_SUPPORT) when adding thread support ). In Windows, this is usually implemented by adding an option in the qconfig. h file. In Unix systems, it is usually added to the Makefile file.