def switch(suspstack):
# suspstack has a handle to target, i.e. where to switch to
ll_assert(suspstack != gcrootfinder.oldsuspstack,
"stacklet: invalid use")
gcrootfinder.newsuspstack = suspstack
h = llop.gc_shadowstackref_context(llmemory.Address, suspstack)
h = llmemory.cast_adr_to_ptr(h, _c.handle)
prepare_old_suspstack()
h = _c.switch(h)
return get_result_suspstack(h)
def _new_callback(h, arg):
# We still have the old shadowstack active at this point; save it
# away, and start a fresh new one
oldsuspstack = gcrootfinder.oldsuspstack
h = llmemory.cast_ptr_to_adr(h)
llop.gc_save_current_state_away(lltype.Void,
oldsuspstack, h)
llop.gc_start_fresh_new_state(lltype.Void)
gcrootfinder.oldsuspstack = NULL_SUSPSTACK
#
newsuspstack = gcrootfinder.callback(oldsuspstack, arg)
#
# Finishing this stacklet.
gcrootfinder.oldsuspstack = NULL_SUSPSTACK
gcrootfinder.newsuspstack = newsuspstack
h = llop.gc_shadowstackref_context(llmemory.Address, newsuspstack)
return llmemory.cast_adr_to_ptr(h, _c.handle)
