/*
 * Coroutine internals
 *
 * 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.
 */

#ifndef QEMU_COROUTINE_INT_H
#define QEMU_COROUTINE_INT_H

#include "qemu/queue.h"
#include "qemu/coroutine.h"

#ifdef CONFIG_SAFESTACK
/* Pointer to the unsafe stack, defined by the compiler */
extern __thread void *__safestack_unsafe_stack_ptr;
#endif

#define COROUTINE_STACK_SIZE (1 << 20)

typedef enum {
    COROUTINE_YIELD = 1,
    COROUTINE_TERMINATE = 2,
    COROUTINE_ENTER = 3,
} CoroutineAction;

struct Coroutine {
    CoroutineEntry *entry;
    void *entry_arg;
    Coroutine *caller;

    /* Only used when the coroutine has terminated.  */
    QSLIST_ENTRY(Coroutine) pool_next;

    size_t locks_held;

    /* Only used when the coroutine has yielded.  */
    AioContext *ctx;

    /* Used to catch and abort on illegal co-routine entry.
     * Will contain the name of the function that had first
     * scheduled the coroutine. */
    const char *scheduled;

    QSIMPLEQ_ENTRY(Coroutine) co_queue_next;

    /* Coroutines that should be woken up when we yield or terminate.
     * Only used when the coroutine is running.
     */
    QSIMPLEQ_HEAD(, Coroutine) co_queue_wakeup;

    QSLIST_ENTRY(Coroutine) co_scheduled_next;
};

Coroutine *qemu_coroutine_new(void);
void qemu_coroutine_delete(Coroutine *co);
CoroutineAction qemu_coroutine_switch(Coroutine *from, Coroutine *to,
                                      CoroutineAction action);

#endif