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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>
#include <sys/types.h>
#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include "coroutine.h"
int coroutine_release(struct coroutine *co)
{
return cc_release(&co->cc);
}
static int _coroutine_release(struct continuation *cc)
{
struct coroutine *co = container_of(cc, struct coroutine, cc);
if (co->release) {
int ret = co->release(co);
if (ret < 0)
return ret;
}
co->caller = NULL;
return 0;
}
static void coroutine_trampoline(struct continuation *cc)
{
struct coroutine *co = container_of(cc, struct coroutine, cc);
co->data = co->entry(co->data);
}
int coroutine_init(struct coroutine *co)
{
if (co->stack_size == 0)
co->stack_size = 16 << 20;
co->cc.stack_size = co->stack_size;
co->cc.stack = mmap(0, co->stack_size,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS,
-1, 0);
if (co->cc.stack == MAP_FAILED)
return -1;
co->cc.entry = coroutine_trampoline;
co->cc.release = _coroutine_release;
co->exited = 0;
return cc_init(&co->cc);
}
#if 0
static __thread struct coroutine leader;
static __thread struct coroutine *current;
#else
static struct coroutine leader;
static struct coroutine *current;
#endif
struct coroutine *coroutine_self(void)
{
if (current == NULL)
current = &leader;
return current;
}
void *coroutine_swap(struct coroutine *from, struct coroutine *to, void *arg)
{
int ret;
to->data = arg;
current = to;
ret = cc_swap(&from->cc, &to->cc);
if (ret == 0)
return from->data;
else if (ret == 1) {
coroutine_release(to);
current = &leader;
to->exited = 1;
return to->data;
}
return NULL;
}
void *coroutine_yieldto(struct coroutine *to, void *arg)
{
if (to->caller) {
fprintf(stderr, "Co-routine is re-entering itself\n");
abort();
}
to->caller = coroutine_self();
return coroutine_swap(coroutine_self(), to, arg);
}
void *coroutine_yield(void *arg)
{
struct coroutine *to = coroutine_self()->caller;
if (!to) {
fprintf(stderr, "Co-routine is yielding to no one\n");
abort();
}
coroutine_self()->caller = NULL;
return coroutine_swap(coroutine_self(), to, arg);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* tab-width: 8
* End:
*/
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