Review for libpthread support
eischen at vigrid.com
Sun Oct 5 13:58:34 PDT 2003
On Sun, 5 Oct 2003, Jake Burkholder wrote:
> On Sunday 05 October 2003 13:46, Daniel Eischen wrote:
> > On Sun, 5 Oct 2003, Jake Burkholder wrote:
> > > On Sunday 05 October 2003 12:21, Daniel Eischen wrote:
> > > > Hi guys,
> > > >
> > > > I have a patch for adding libpthread support for sparc64. It's jake's
> > > > patch, with a few mods by myself. I'd like for some folks to look it
> > > > over. I haven't tested it; I need a couple of questions answered
> > > > first so I can fill in a missing piece.
> > > >
> > > > o Can someone look at the end of __thr_getcontext (line 524 of
> > > > the patch)? I need to test %i2 for NULL and branch to 1 if true.
> > > >
> > > > +/* bz %i2, 1f */
> > > > + stx %i1, [%i2]
> > > > +1: ldx [%sp], %i1 /* restore %i1 */
> > > > + ldx [%sp + 8], %i2 /* restore %i2 */
> > >
> > > brz. Beware of delay slots, the instruction after a branch is executed
> > > before the branch is taken.
> > OK.
> > > Use the locals as temporaries instead of using the stack, eg
> > What if a thread gets interrupted while using locals? _thr_setcontext()
> > is suppose to be able to resume a thread that was interrupted anywhere.
> > What if some library function used locals, thread T1 had a page
> > fault, and it's context was exported back to libpthread? The
> > library may run other threads before resuming T1 again.
> They're part of T1's context. They'll get saved on T1's stack on entry to the
> kernel to handle the page fault.
Oh, so they're not stored in the mcontext, but when resumed
they'll be popped off the stack.
Thanks, I'll use the local's then.
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