/////////////////////////////////////////////////////////////////////////////
-// Name: thread
+// Name: thread.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/////////////////////////////////////////////////////////////////////////////
/*!
-
- @page thread_overview Multithreading overview
-
- Classes: #wxThread, #wxMutex,
- #wxCriticalSection,
- #wxCondition
+
+ @page overview_thread Multithreading overview
+
+ Classes: #wxThread, #wxMutex, #wxCriticalSection, #wxCondition
+
wxWidgets provides a complete set of classes encapsulating objects necessary in
- multithreaded (MT) programs: the #thread class itself and different
- synchronization objects: #mutexes and
- @ref criticalsection_overview with
- #conditions. The thread API in wxWidgets 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.
+ multithreaded (MT) programs: the wxThread class itself and different
+ synchronization objects: mutexes (see wxMutex) and critical sections (see
+ wxCriticalSection) with conditions (see wxCondition). The thread API in wxWidgets
+ 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 a non-trivial undertaking especially for large
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
- @ref idleevent_overview or even simply do everything at once
- but call wxWindow::Update() periodically to update
- the screen.
+ dialog example it is far better to do the calculations in the idle handler
+ (see @ref wxIdleEvent) or even simply do everything at once but call wxWindow::Update()
+ periodically to update the screen.
+
If you do decide to use threads in your application, it is strongly recommended
that no more than one thread calls GUI functions. The thread sample shows that
it @e is possible for many different threads to call GUI functions at once
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).
- For communication between secondary threads and the main thread, you may use
- wxEvtHandler::AddPendingEvent
- or its short version #wxPostEvent. These functions
+
+ For communication between secondary threads and the main thread, you may use
+ wxEvtHandler::AddPendingEvent or its short version #wxPostEvent. These functions
have a thread-safe implementation so that they can be used as they are for
sending events from one thread to another. However there is no built in method
to send messages to the worker threads and you will need to use the available
synchronization classes to implement the solution which suits your needs
yourself. In particular, please note that it is not enough to derive
- your class from #wxThread and
- #wxEvtHandler to send messages to it: in fact, this does
- not work at all.
-
- */
-
-
+ your class from #wxThread and #wxEvtHandler to send messages to it:
+ in fact, this does not work at all.
+
+*/
+