void * GC_mark_thread(void * id)
{
word my_mark_no = 0;
marker_sp[(word)id] = GC_approx_sp();
# ifdef IA64
marker_bsp[(word)id] = GC_save_regs_in_stack();
# endif
for (;; ++my_mark_no) {
/* GC_mark_no is passed only to allow GC_help_marker to terminate */
/* promptly. This is important if it were called from the signal */
/* handler or from the GC lock acquisition code. Under Linux, it's */
/* not safe to call it from a signal handler, since it uses mutexes */
/* and condition variables. Since it is called only here, the */
/* argument is unnecessary. */
if (my_mark_no < GC_mark_no || my_mark_no > GC_mark_no + 2) {
/* resynchronize if we get far off, e.g. because GC_mark_no */
/* wrapped. */
my_mark_no = GC_mark_no;
}
# ifdef DEBUG_THREADS
GC_printf("Starting mark helper for mark number %lu\n", my_mark_no);
# endif
GC_help_marker(my_mark_no);
}
}
/* ctxt is either a pointer to a ucontext_t we generated, or NULL. */
void GC_with_callee_saves_pushed(void (*fn)(ptr_t, void *),
ptr_t arg)
{
word dummy;
void * context = 0;
# if defined(HAVE_PUSH_REGS)
GC_push_regs();
# elif defined(UNIX_LIKE) && !defined(DARWIN) && !defined(ARM32)
/* Older versions of Darwin seem to lack getcontext(). */
/* ARM Linux often doesn't support a real getcontext(). */
ucontext_t ctxt;
if (getcontext(&ctxt) < 0)
ABORT ("Getcontext failed: Use another register retrieval method?");
context = &ctxt;
# if defined(SPARC) || defined(IA64)
/* On a register window machine, we need to save register */
/* contents on the stack for this to work. This may already be */
/* subsumed by the getcontext() call. */
{
GC_save_regs_ret_val = GC_save_regs_in_stack();
}
# endif /* register windows. */
# elif defined(HAVE_BUILTIN_UNWIND_INIT)
/* This was suggested by Richard Henderson as the way to */
/* force callee-save registers and register windows onto */
/* the stack. */
__builtin_unwind_init();
# else /* !HAVE_BUILTIN_UNWIND_INIT && !UNIX_LIKE */
/* && !HAVE_PUSH_REGS */
/* Generic code */
/* The idea is due to Parag Patel at HP. */
/* We're not sure whether he would like */
/* to be he acknowledged for it or not. */
jmp_buf regs;
register word * i = (word *) regs;
register ptr_t lim = (ptr_t)(regs) + (sizeof regs);
/* Setjmp doesn't always clear all of the buffer. */
/* That tends to preserve garbage. Clear it. */
for (; (char *)i < lim; i++) {
*i = 0;
}
# if defined(MSWIN32) || defined(MSWINCE) \
|| defined(UTS4) || defined(LINUX) || defined(EWS4800)
(void) setjmp(regs);
# else
(void) _setjmp(regs);
/* We don't want to mess with signals. According to */
/* SUSV3, setjmp() may or may not save signal mask. */
/* _setjmp won't, but is less portable. */
# endif
# endif /* !HAVE_PUSH_REGS ... */
fn(arg, context);
/* Strongly discourage the compiler from treating the above */
/* as a tail-call, since that would pop the register */
/* contents before we get a chance to look at them. */
GC_noop1((word)(&dummy));
}
