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/* Copyright (C) 2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <ucontext.h>
#define UC_M_PC 40
#define UC_M_NPC 48
extern int __getcontext (ucontext_t *ucp);
extern int __setcontext (const ucontext_t *ucp, int restoremask);
int
swapcontext (ucontext_t *oucp, const ucontext_t *ucp)
{
extern void __swapcontext_ret (void);
/* Save the current machine context to oucp. */
__getcontext (oucp);
/* Modify oucp to skip the __setcontext call on reactivation. */
*(long*)((char*)oucp+UC_M_PC) = (long)__swapcontext_ret;
*(long*)((char*)oucp+UC_M_NPC) = (long)__swapcontext_ret + 4;
/* Restore the machine context in ucp. */
__setcontext (ucp, 1);
return 0;
}
asm (" \n\
.text \n\
.type __swapcontext_ret, #function \n\
__swapcontext_ret: \n\
return %i7 + 8 \n\
clr %o0 \n\
.size __swapcontext_ret, .-__swapcontext_ret \n\
");
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