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| author | Matthias Melcher <fltk@matthiasm.com> | 2007-01-18 22:48:19 +0000 |
|---|---|---|
| committer | Matthias Melcher <fltk@matthiasm.com> | 2007-01-18 22:48:19 +0000 |
| commit | 8e7e4167835186b2aab81c4e87153c574ff83466 (patch) | |
| tree | ac7477a7e08300317717a84b94ac2527ec26c94e /documentation/advanced.html | |
| parent | bb6f36cffe66509ebcc6da6d1a8d98cf48a0b749 (diff) | |
Added chapter 10 with documentation about multithreading
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@5621 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
Diffstat (limited to 'documentation/advanced.html')
| -rw-r--r-- | documentation/advanced.html | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/documentation/advanced.html b/documentation/advanced.html new file mode 100644 index 000000000..52c3009b6 --- /dev/null +++ b/documentation/advanced.html @@ -0,0 +1,89 @@ +<HTML> +<HEAD> + <TITLE>10 - Advanced FLTK</TITLE> +</HEAD> +<BODY> + +<H1 ALIGN="RIGHT"><A NAME="advanced">10 - Advanced FLTK</A></H1> + +<P>This chapter explains advanced programming and design topics +that will help you to get the most out of FLTK.</P> + +<H2><A NAME="multithreading">10.1 Multithreading</H2> + +<P>FLTK supports multithreaded application using a locking mechanism +based on "pthreads". We do not provide a threading interface +as part of the library. However a simple example how threads can +be implemented for all supported platforms can be found in +<tt>test/threads.h</tt> and <tt>test/threads.cxx</tt>. + +<P>To use the locking mechanism, the command line version of FLTK +must be compiled with <tt>--enable-threads</tt> set during the +<tt>configure</tt> process. IDE-based versions of FLTK are +automatically compiled with locking enabled if possible. + +<P>In <TT>main()</TT>, before calling <TT>Fl::run()</TT>, call +<TT>Fl::lock()</TT>. This will startup the runtime multithreading +support for your program. All callbacks and derived functions +like <tt>handle()</tt> and <tt>draw()</tt> will now be properly +locked. + +<pre> + main() { + <a href="Fl.html#Fl.lock">Fl::lock()</a>; + /* run thread */ + while(Fl::wait() > 0) { + if(<a href="Fl.html#Fl.thread_message">Fl::thread_message()</a>) { + /* process your data */ + } + } + } + +</pre> + +<P>You can now start as many threads as you like. From within +a thread (other than the main thread) FLTK calls must be wrapped +in the following code: + +<pre> + <a href="Fl.html#Fl.lock">Fl::lock()</a>; // avoid conflicting calls + ... // your code here + <a href="Fl.html#Fl.unlock">Fl::unlock()</a>; // allow other threads to access FLTK again + <a href="Fl.html#Fl.awake">Fl::awake(msg)</a>; // tells FLTK that another thread has made changes + +</pre> + +<P>FLTK supports multiple platforms, some of them which do not +allow any other but the main thread to handle system events and +open or close windows. The safe thing to do is to adhere to the +following rulesi for threads on all operating systems. + +<ul> + +<li>don't <tt>show()</tt> or <tt>hide()</tt>anything that contains +widgets derived from <tt>Fl_Window</tt>, including dialogs, file +choosers, subwindows or <tt>Fl_GL_Window</tt>s</li> + +<li>don't call <tt>Fl::wait()</tt>, <tt>Fl::flush()</tt> or any +related methods that will handle system messages</li> + +<li>don't start or cancel timers</li> + +<li>don't change window decorations or titles</li> + +<li><tt>make_current()</tt> may or may not work well for regular +windows, but should always work for <tt>Fl_GL_Window</tt>s to +allow for high speed rendering on graphics cards with multiple +pipelines</li> + +</ul> + +<P>See also: +<a href="Fl.html#Fl.lock">void lock()</A>, +<a href="Fl.html#Fl.unlock">void unlock()</A>, +<a href="Fl.html#Fl.awake">void awake(void *message)</A>, +<a href="Fl.html#Fl.thread_message">void *thread_message()</A>. + + +</BODY> +</HTML> |