static void
fiber_set_stack_location(void)
{
rb_thread_t *th = GET_THREAD();
VALUE *ptr;
SET_MACHINE_STACK_END(&ptr);
th->machine_stack_start = (void*)(((VALUE)ptr & RB_PAGE_MASK) + STACK_UPPER((void *)&ptr, 0, RB_PAGE_SIZE));
}
static void
cont_save_machine_stack(rb_thread_t *th, rb_context_t *cont)
{
size_t size;
rb_thread_t *sth = &cont->saved_thread;
SET_MACHINE_STACK_END(&th->machine_stack_end);
#ifdef __ia64
th->machine_register_stack_end = rb_ia64_bsp();
#endif
if (th->machine_stack_start > th->machine_stack_end) {
size = cont->machine_stack_size = th->machine_stack_start - th->machine_stack_end;
cont->machine_stack_src = th->machine_stack_end;
}
else {
size = cont->machine_stack_size = th->machine_stack_end - th->machine_stack_start;
cont->machine_stack_src = th->machine_stack_start;
}
if (cont->machine_stack) {
REALLOC_N(cont->machine_stack, VALUE, size);
}
else {
cont->machine_stack = ALLOC_N(VALUE, size);
}
FLUSH_REGISTER_WINDOWS;
MEMCPY(cont->machine_stack, cont->machine_stack_src, VALUE, size);
#ifdef __ia64
rb_ia64_flushrs();
size = cont->machine_register_stack_size = th->machine_register_stack_end - th->machine_register_stack_start;
cont->machine_register_stack_src = th->machine_register_stack_start;
if (cont->machine_register_stack) {
REALLOC_N(cont->machine_register_stack, VALUE, size);
}
else {
cont->machine_register_stack = ALLOC_N(VALUE, size);
}
MEMCPY(cont->machine_register_stack, cont->machine_register_stack_src, VALUE, size);
#endif
sth->machine_stack_start = sth->machine_stack_end = 0;
#ifdef __ia64
sth->machine_register_stack_start = sth->machine_register_stack_end = 0;
#endif
}
static void
fiber_setcontext(rb_fiber_t *newfib, rb_fiber_t *oldfib)
{
rb_thread_t *th = GET_THREAD(), *sth = &newfib->cont.saved_thread;
if (newfib->status != RUNNING) {
fiber_initialize_machine_stack_context(newfib, FIBER_MACHINE_STACK_ALLOCATION_SIZE);
}
/* restore thread context */
cont_restore_thread(&newfib->cont);
th->machine_stack_maxsize = sth->machine_stack_maxsize;
if (sth->machine_stack_end && (newfib != oldfib)) {
rb_bug("fiber_setcontext: sth->machine_stack_end has non zero value");
}
/* save oldfib's machine stack */
if (oldfib->status != TERMINATED) {
STACK_GROW_DIR_DETECTION;
SET_MACHINE_STACK_END(&th->machine_stack_end);
if (STACK_DIR_UPPER(0, 1)) {
oldfib->cont.machine_stack_size = th->machine_stack_start - th->machine_stack_end;
oldfib->cont.machine_stack = th->machine_stack_end;
}
else {
oldfib->cont.machine_stack_size = th->machine_stack_end - th->machine_stack_start;
oldfib->cont.machine_stack = th->machine_stack_start;
}
}
/* exchange machine_stack_start between oldfib and newfib */
oldfib->cont.saved_thread.machine_stack_start = th->machine_stack_start;
th->machine_stack_start = sth->machine_stack_start;
/* oldfib->machine_stack_end should be NULL */
oldfib->cont.saved_thread.machine_stack_end = 0;
#ifndef _WIN32
if (!newfib->context.uc_stack.ss_sp && th->root_fiber != newfib->cont.self) {
rb_bug("non_root_fiber->context.uc_stac.ss_sp should not be NULL");
}
#endif
/* swap machine context */
#ifdef _WIN32
SwitchToFiber(newfib->fib_handle);
#else
swapcontext(&oldfib->context, &newfib->context);
#endif
}
