Archipelago » qemu

/*

 * Win32 coroutine initialization code

 *

 * Copyright (c) 2011 Kevin Wolf <kwolf@redhat.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "qemu-common.h"

#include "block/coroutine_int.h"

typedef struct

{

    Coroutine base;

    LPVOID fiber;

    CoroutineAction action;

} CoroutineWin32;

static __thread CoroutineWin32 leader;

static __thread Coroutine *current;

CoroutineAction qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,

                                      CoroutineAction action)

{

    CoroutineWin32 *from = DO_UPCAST(CoroutineWin32, base, from_);

    CoroutineWin32 *to = DO_UPCAST(CoroutineWin32, base, to_);

    current = to_;

    to->action = action;

    SwitchToFiber(to->fiber);

    return from->action;

}

static void CALLBACK coroutine_trampoline(void *co_)

{

    Coroutine *co = co_;

    while (true) {

        co->entry(co->entry_arg);

        qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE);

    }

}

Coroutine *qemu_coroutine_new(void)

{

    const size_t stack_size = 1 << 20;

    CoroutineWin32 *co;

    co = g_malloc0(sizeof(*co));

    co->fiber = CreateFiber(stack_size, coroutine_trampoline, &co->base);

    return &co->base;

}

void qemu_coroutine_delete(Coroutine *co_)

{

    CoroutineWin32 *co = DO_UPCAST(CoroutineWin32, base, co_);

    DeleteFiber(co->fiber);

    g_free(co);

}

Coroutine *qemu_coroutine_self(void)

{

    if (!current) {

        current = &leader.base;

        leader.fiber = ConvertThreadToFiber(NULL);

    }

    return current;

}

bool qemu_in_coroutine(void)

{

    return current && current->caller;

}