X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/99f09bc1b9cbc93a6cc952ec2c777d999d5483d0..d1853d4765d02a9842c7a8721ef2329d09429262:/docs/latex/wx/tthreads.tex?ds=sidebyside diff --git a/docs/latex/wx/tthreads.tex b/docs/latex/wx/tthreads.tex index a034599c70..26d769af94 100644 --- a/docs/latex/wx/tthreads.tex +++ b/docs/latex/wx/tthreads.tex @@ -8,11 +8,14 @@ wxWindows provides a complete set of classes encapsulating objects necessary in multithreaded (MT) programs: the \helpref{thread}{wxthread} class itself and different synchronization objects: \helpref{mutexes}{wxmutex} and \helpref{critical sections}{wxcriticalsection} with -\helpref{conditions}{wxcondition}. +\helpref{conditions}{wxcondition}. The thread API in wxWindows resembles to +POSIX1.c threads API (a.k.a. pthreads), although several functions have +different names and some features inspired by Win32 thread API are there as +well. These classes will hopefully make writing MT programs easier and they also provide some extra error checking (compared to the native (be it Win32 or Posix) -thread API), however it is still an untrivial undertaking especially for large +thread API), however it is still an non-trivial undertaking especially for large projects. Before starting an MT application (or starting to add MT features to an existing one) it is worth asking oneself if there is no easier and safer way to implement the same functionality. Of course, in some situations threads @@ -21,7 +24,7 @@ new thread for each new client), but in others it might be a very poor choice (example: launching a separate thread when doing a long computation to show a progress dialog). Other implementation choices are available: for the progress dialog example it is far better to do the calculations in the -\helpref{idle handler}{wxidleevent} or call \helpref{wxYield()}{wxyield} +\helpref{idle handler}{wxidleevent} or call \helpref{wxYield()}{wxyield} periodically to update the screen. If you do decide to use threads in your application, it is strongly recommended @@ -34,9 +37,10 @@ more robust and will undoubtedly save you countless problems (example: under Win32 a thread can only access GDI objects such as pens, brushes, \&c created by itself and not by the other threads). -Final note: in the current release of wxWindows, there are no specific -facilities for communicating between the threads. However, the usual -\helpref{ProcessEvent()}{wxevthandlerprocessevent} function may be used for -thread communication too - but you should provide your own synchronisation -mechanism if you use it (e.g. just use a critical section before sending a -message) because there is no built-in synchronisation. +For communication between threads, use +\helpref{wxEvtHandler::AddPendingEvent}{wxevthandleraddpendingevent} +or its short version \helpref{wxPostEvent}{wxpostevent}. These functions +have thread safe implementation so that they can be used as they are for +sending event from one thread to another. + +