1 20f5692b 2012-07-14 rsc #include "threadimpl.h"
 2 20f5692b 2012-07-14 rsc 
 3 20f5692b 2012-07-14 rsc void
 4 20f5692b 2012-07-14 rsc makecontext(ucontext_t *uc, void (*fn)(void), int argc, ...)
 5 20f5692b 2012-07-14 rsc {
 6 20f5692b 2012-07-14 rsc 	uintptr *sp;
 7 20f5692b 2012-07-14 rsc 	va_list arg;
 8 20f5692b 2012-07-14 rsc 
 9 20f5692b 2012-07-14 rsc //fprint(2, "makecontext %d\n", argc);
10 20f5692b 2012-07-14 rsc 	if(argc != 2)
11 20f5692b 2012-07-14 rsc 		sysfatal("libthread: makecontext misused");
12 20f5692b 2012-07-14 rsc 	va_start(arg, argc);
13 20f5692b 2012-07-14 rsc 	uc->mc.di = va_arg(arg, uint);
14 20f5692b 2012-07-14 rsc 	uc->mc.si = va_arg(arg, uint);
15 20f5692b 2012-07-14 rsc //fprint(2, "%ux %ux\n", uc->mc.di, uc->mc.si);
16 20f5692b 2012-07-14 rsc 	va_end(arg);
17 20f5692b 2012-07-14 rsc 
18 20f5692b 2012-07-14 rsc 	sp = (uintptr*)((char*)uc->uc_stack.ss_sp+uc->uc_stack.ss_size);
19 20f5692b 2012-07-14 rsc 	*--sp = 0;  // fn's return address
20 20f5692b 2012-07-14 rsc 	*--sp = (uintptr)fn;  // return address of setcontext
21 20f5692b 2012-07-14 rsc 	uc->mc.sp = (uintptr)sp;
22 20f5692b 2012-07-14 rsc }
23 20f5692b 2012-07-14 rsc 
24 20f5692b 2012-07-14 rsc int
25 20f5692b 2012-07-14 rsc swapcontext(ucontext_t *oucp, ucontext_t *ucp)
26 20f5692b 2012-07-14 rsc {
27 20f5692b 2012-07-14 rsc 	if(getcontext(oucp) == 0)
28 20f5692b 2012-07-14 rsc 		setcontext(ucp);
29 20f5692b 2012-07-14 rsc 	return 0;
30 20f5692b 2012-07-14 rsc }
31 20f5692b 2012-07-14 rsc 
32 20f5692b 2012-07-14 rsc