sometimes called {\it light-weight processes}, but the fundamental difference
between threads and processes is that memory spaces of different processes are
separated while all threads share the same address space. While it makes it
-much easier to share common data between several threads, it also makes much
+much easier to share common data between several threads, it also makes it much
easier to shoot oneself in the foot, so careful use of synchronization objects
such as \helpref{mutexes}{wxmutex} and/or \helpref{critical sections}{wxcriticalsection} is recommended.
-There are two types of threads in wxWindows: {\it detached} and {\it joinable}
+There are two types of threads in wxWidgets: {\it detached} and {\it joinable}
ones, just as in the POSIX thread API (but unlike Win32 threads where all threads
are joinable). The difference between the two is that only joinable threads
can return a return code -- this is returned by the Wait() function. Detached
threads may be created on the stack although more usually they will be created
on the heap as well. Don't create global thread objects because they allocate
memory in their constructor, which will cause problems for the memory checking
-system.
+system. Finally, another consequence of the handling of the above is that you
+should never delete a detached thread yourself, as this will be done by the
+thread itself when it terminates.
\wxheading{Derived from}
\end{twocollist}
-\membersection{wxThread::\destruct{wxThread}}
+\membersection{wxThread::\destruct{wxThread}}\label{wxthreaddtor}
\func{}{\destruct{wxThread}}{\void}
Creates a new thread. The thread object is created in the suspended state, and you
should call \helpref{Run}{wxthreadrun} to start running it. You may optionally
specify the stack size to be allocated to it (Ignored on platforms that don't
-support setting it explicitly, eg. Unix).
+support setting it explicitly, eg. Unix system without
+\texttt{pthread\_attr\_setstacksize}). If you do not specify the stack size,
+the system's default value is used.
+
+{\bf Warning:} It is a good idea to explicitly specify a value as systems'
+default values vary from just a couple of KB on some systems (BSD and
+OS/2 systems) to one or several MB (Windows, Solaris, Linux). So, if you
+have a thread that requires more than just a few KB of memory, you will
+have mysterious problems on some platforms but not on the common ones. On the
+other hand, just indicating a large stack size by default will give you
+performance issues on those systems with small default stack since those
+typically use fully committed memory for the stack. On the contrary, if
+use a lot of threads (say several hundred), virtual adress space can get tight
+unless you explicitly specify a smaller amount of thread stack space for each
+thread.
+
\wxheading{Return value}
Calling \helpref{Delete}{wxthreaddelete} is a graceful way to terminate the
thread. It asks the thread to terminate and, if the thread code is well
-written, the thread will terminate after the next call to
+written, the thread will terminate after the next call to
\helpref{TestDestroy}{wxthreadtestdestroy} which should happen quite soon.
However, if the thread doesn't call \helpref{TestDestroy}{wxthreadtestdestroy}
The returned value is the thread exit code which is only useful for
joinable threads and is the value returned by \helpref{Wait}{wxthreadwait}.
-This function is called by wxWindows itself and should never be called
+This function is called by wxWidgets itself and should never be called
directly.
Returns \true if the thread is alive (i.e. started and not terminating).
-Note that this function can only be saely used with joinable threads, not
+Note that this function can only safely be used with joinable threads, not
detached ones as the latter delete themselves and so when the real thread is
-not alive any longer it is not possible to call this function neither because
-the wxThread object doesn't exist any more as well.
-
+no longer alive, it is not possible to call this function because
+the wxThread object no longer exists.
\membersection{wxThread::IsDetached}\label{wxthreadisdetached}
number of threads that the system tries to schedule to run in parallel.
The value of $0$ for {\it level} may be used to set the default one.
-Returns true on success or false otherwise (for example, if this function is
+Returns \true on success or false otherwise (for example, if this function is
not implemented for this platform -- currently everything except Solaris).
\membersection{wxThread::TestDestroy}\label{wxthreadtestdestroy}
-\func{bool}{TestDestroy}{\void}
+\func{virtual bool}{TestDestroy}{\void}
This function should be called periodically by the thread to ensure that calls
to \helpref{Pause}{wxthreadpause} and \helpref{Delete}{wxthreaddelete} will
-work. If it returns true, the thread should exit as soon as possible.
+work. If it returns \true, the thread should exit as soon as possible.
+
+Notice that under some platforms (POSIX), implementation of
+\helpref{Pause}{wxthreadpause} also relies on this function being called, so
+not calling it would prevent both stopping and suspending thread from working.
\membersection{wxThread::This}\label{wxthreadthis}
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