[uae] Re: How is the Mac OS X binary built?
- From: Richard Drummond <evilrich@xxxxxxxxxxxxxx>
- To: uae@xxxxxxxxxxxxx
- Date: Mon, 10 May 2004 14:43:12 -0500
Hi Byron
On Sunday 09 May 2004 11:20 pm, Byron Q. Desnoyers Winmill wrote:
> After adding the filesystem option to my .uaerc file, the binaries
> I build generate a bus error. This problem is not evident in the
> official binary (I'm using uae-0.8.25-20040302-osx-sdl.zip). It
> would be nice to build my own functional binaries for two reasons:
> X is faster than SDL under Mac OS X, and I like avoiding too many
> dependencies (ie. gtk+ and libsdl).
The problem is with pthreads under OS X. Semaphores don't work when UAE is
built for OS X using pthreads. I never had the time to track down what
exactly is causing the problem - either semaphores in the OS X implementation
of pthreads are broken, or are subtly different in some way from POSIX
semaphores.
> The problem appears to be in the filesys_thread().
> The bus error is generated when the following line is called:
> put_long (get_long (morelocks), get_long (ui->self->locklist));
> I have established that morelocks = 0, immediately after the call:
> morelocks = (uae_u32)read_comm_pipe_int_blocking (ui->unit_pipe);
> This is what it would return if td-none/thread.h was included,
> though there may be other circumstances when this would happen
> (because I really don't understand what is going on here :).
The pipe stuff in UAE is for IPC. It implements a primitive kind of
message-passing between threads. Of course, this requires semaphores for
mutual exclusion.
> I've tried building with a plain "./configure" and a ever so slightly
> less plain "./configure --disable-threads". The same chunk of code
> is being called in both cases (it doesn't look like it should be,
> if I believe the #ifdef). Of course, gtk+ and sdl aren't detected
> because they don't exist (well, the libraries for the latter are
> there -- but not the headers).
Threads are currently needed for the hard-drive emulation. In theory, they
shouldn't be. The virtual filesystem can be built not to use threads.
However, the hard file stuff does require threads - and it's currently not
possible to have the former without the latter. I've been meaning to sort
that out, primarily for this very reason - so that you can build in
hard-drive emulation without using threads.
In summary, the easy answer to your problem is either to build against SDL on
OS X or don't build hard-drive emulation. For a proper solution, we need to
find out what's going wrong with pthreads in OS X and/or to allow the
building of virtual filesystem emulation without hard file emulation (or
re-work the hardfile emulation so that it'll also work without threads).
Cheers,
Rich
Other related posts:
