This function doesn’t return a value, implying that it can’t fail. To create such a lock, all you needed was to allocate a CRITICAL_SECTION structure and call the InitializeCriticalSection function to prepare it for use. When I first started using critical sections, they were really simple. This lock is used heavily by countless applications but has a sordid history. Critical Sectionįirst up is the critical section object. If, however, portability is less of a concern and performance is paramount, then getting familiar with what Windows now offers will be important. If portability is your main concern, then the new C++ library additions will be very appealing. I’ll start with a review of the synchronization primitives provided by Windows itself and then consider the alternatives provided by the Standard C++ Library.
In this month’s column I’m going to explore the state of synchronization in Windows and C++. Windows now supports many more synchronization functions, and C++ itself at long last provides an interesting collection of concurrency and synchronization capabilities for those using a compiler supporting the C++11 standard. There are a plethora of choices for the C++ programmer. Today the synchronization landscape has changed dramatically. These two lock objects have different capabilities, but it’s helpful to remember that they’re just locks, they both provide mutual exclusion guarantees and both can be used to demarcate critical sections of code. To ensure correctness, only one thread can execute this critical section of code at a time. The critical section takes its name from the actual section of code that might be accessing such a resource. It refers to the guarantee that only one thread can access some resource at a time.
The mutex takes its name from the concept of “mutual exclusion,” another name for synchronization. In general terms, both of these are locks, or lock objects. I tended to use a critical section unless I needed to synchronize across processes, in which case I used a mutex. Windows itself had only a handful of synchronization primitives, all of which were implemented in the kernel. When I first started writing concurrent software, C++ had no support for synchronization. Volume 27 Number 11 Windows with C++ - The Evolution of Synchronization in Windows and C++
0 kommentar(er)
