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/*
* GTK VNC Widget
*
* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
*
* This 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 2.0 of the License, or (at your option) any later version.
*
* This 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#undef _FORTIFY_SOURCE
#include "continuation.h"
/*
* va_args to makecontext() must be type 'int', so passing
* the pointer we need may require several int args. This
* union is a quick hack to let us do that
*/
union cc_arg {
void *p;
int i[2];
};
static void continuation_trampoline(int i0, int i1)
{
union cc_arg arg;
struct continuation *cc;
arg.i[0] = i0;
arg.i[1] = i1;
cc = arg.p;
if (_setjmp(cc->jmp) == 0) {
ucontext_t tmp;
swapcontext(&tmp, &cc->last);
}
cc->entry(cc);
}
int cc_init(struct continuation *cc)
{
volatile union cc_arg arg;
arg.p = cc;
if (getcontext(&cc->uc) == -1)
return -1;
cc->uc.uc_link = &cc->last;
cc->uc.uc_stack.ss_sp = cc->stack;
cc->uc.uc_stack.ss_size = cc->stack_size;
cc->uc.uc_stack.ss_flags = 0;
makecontext(&cc->uc, (void *)continuation_trampoline, 2, arg.i[0], arg.i[1]);
swapcontext(&cc->last, &cc->uc);
return 0;
}
int cc_release(struct continuation *cc)
{
if (cc->release)
return cc->release(cc);
return 0;
}
int cc_swap(struct continuation *from, struct continuation *to)
{
to->exited = 0;
if (getcontext(&to->last) == -1)
return -1;
else if (to->exited == 0)
to->exited = 1; // so when coroutine finishes
else if (to->exited == 1)
return 1; // it ends up here
if (_setjmp(from->jmp) == 0)
_longjmp(to->jmp, 1);
return 0;
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* tab-width: 8
* End:
*/
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