Archipelago » qemu

/*

 * QEMU coroutines

 *

 * Copyright IBM, Corp. 2011

 *

 * Authors:

 *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>

 *  Kevin Wolf         <kwolf@redhat.com>

 *

 * This work is licensed under the terms of the GNU LGPL, version 2 or later.

 * See the COPYING.LIB file in the top-level directory.

 *

 */

#include "trace.h"

#include "qemu-common.h"

#include "block/coroutine.h"

#include "block/coroutine_int.h"

Coroutine *qemu_coroutine_create(CoroutineEntry *entry)

{

    Coroutine *co = qemu_coroutine_new();

    co->entry = entry;

    return co;

}

static void coroutine_swap(Coroutine *from, Coroutine *to)

{

    CoroutineAction ret;

    ret = qemu_coroutine_switch(from, to, COROUTINE_YIELD);

    switch (ret) {

    case COROUTINE_YIELD:

        return;

    case COROUTINE_TERMINATE:

        trace_qemu_coroutine_terminate(to);

        qemu_coroutine_delete(to);

        return;

    default:

        abort();

    }

}

void qemu_coroutine_enter(Coroutine *co, void *opaque)

{

    Coroutine *self = qemu_coroutine_self();

    trace_qemu_coroutine_enter(self, co, opaque);

    if (co->caller) {

        fprintf(stderr, "Co-routine re-entered recursively\n");

        abort();

    }

    co->caller = self;

    co->entry_arg = opaque;

    coroutine_swap(self, co);

}

void coroutine_fn qemu_coroutine_yield(void)

{

    Coroutine *self = qemu_coroutine_self();

    Coroutine *to = self->caller;

    trace_qemu_coroutine_yield(self, to);

    if (!to) {

        fprintf(stderr, "Co-routine is yielding to no one\n");

        abort();

    }

    self->caller = NULL;

    coroutine_swap(self, to);

}