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/*
 * Copyright (c) 2006 Ondrej Palkovsky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */

/**
 * Asynchronous library
 *
 * The aim of this library is to provide a facility for writing programs which
 * utilize the asynchronous nature of HelenOS IPC, yet using a normal way of
 * programming.
 *
 * You should be able to write very simple multithreaded programs, the async
 * framework will automatically take care of most synchronization problems.
 *
 * Default semantics:
 * - async_send_*(): Send asynchronously. If the kernel refuses to send
 *                   more messages, [ try to get responses from kernel, if
 *                   nothing found, might try synchronous ]
 *
 * Example of use (pseudo C):
 *
 * 1) Multithreaded client application
 *
 *   fibril_create(fibril1, ...);
 *   fibril_create(fibril2, ...);
 *   ...
 *
 *   int fibril1(void *arg)
 *   {
 *     conn = ipc_connect_me_to();
 *     c1 = async_send(conn);
 *     c2 = async_send(conn);
 *     async_wait_for(c1);
 *     async_wait_for(c2);
 *     ...
 *   }
 *
 *
 * 2) Multithreaded server application
 *
 *   main()
 *   {
 *     async_manager();
 *   }
 *
 *   my_client_connection(icallid, *icall)
 *   {
 *     if (want_refuse) {
 *       ipc_answer_0(icallid, ELIMIT);
 *       return;
 *     }
 *     ipc_answer_0(icallid, EOK);
 *
 *     callid = async_get_call(&call);
 *     handle_call(callid, call);
 *     ipc_answer_2(callid, 1, 2, 3);
 *
 *     callid = async_get_call(&call);
 *     ...
 *   }
 *
 */

#include <futex.h>
#include <async.h>
#include <fibril.h>
#include <stdio.h>
#include <adt/hash_table.h>
#include <adt/list.h>
#include <ipc/ipc.h>
#include <assert.h>
#include <errno.h>
#include <sys/time.h>
#include <arch/barrier.h>
#include <bool.h>

atomic_t async_futex = FUTEX_INITIALIZER;

/** Structures of this type represent a waiting fibril. */
typedef struct {
    /** Expiration time. */
    struct timeval expires;
    
    /** If true, this struct is in the timeout list. */
    bool inlist;
    
    /** Timeout list link. */
    link_t link;
    
    /** Identification of and link to the waiting fibril. */
    fid_t fid;
    
    /** If true, this fibril is currently active. */
    bool active;
    
    /** If true, we have timed out. */
    bool timedout;
} awaiter_t;

typedef struct {
    awaiter_t wdata;
    
    /** If reply was received. */
    bool done;
    
    /** Pointer to where the answer data is stored. */
    ipc_call_t *dataptr;
    
    ipcarg_t retval;
} amsg_t;

/**
 * Structures of this type are used to group information about a call and a
 * message queue link.
 */
typedef struct {
    link_t link;
    ipc_callid_t callid;
    ipc_call_t call;
} msg_t;

typedef struct {
    awaiter_t wdata;
    
    /** Hash table link. */
    link_t link;
    
    /** Incoming phone hash. */
    ipcarg_t in_phone_hash;
    
    /** Messages that should be delivered to this fibril. */
    link_t msg_queue;
    
    /** Identification of the opening call. */
    ipc_callid_t callid;
    /** Call data of the opening call. */
    ipc_call_t call;
    
    /** Identification of the closing call. */
    ipc_callid_t close_callid;
    
    /** Fibril function that will be used to handle the connection. */
    void (*cfibril)(ipc_callid_t, ipc_call_t *);
} connection_t;

/** Identifier of the incoming connection handled by the current fibril. */
fibril_local connection_t *FIBRIL_connection;

static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);
static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call);

/**
 * Pointer to a fibril function that will be used to handle connections.
 */
static async_client_conn_t client_connection = default_client_connection;

/**
 * Pointer to a fibril function that will be used to handle interrupt
 * notifications.
 */
static async_client_conn_t interrupt_received = default_interrupt_received;

static hash_table_t conn_hash_table;
static LIST_INITIALIZE(timeout_list);

#define CONN_HASH_TABLE_CHAINS  32

/** Compute hash into the connection hash table based on the source phone hash.
 *
 * @param key Pointer to source phone hash.
 *
 * @return Index into the connection hash table.
 *
 */
static hash_index_t conn_hash(unsigned long *key)
{
    assert(key);
    return (((*key) >> 4) % CONN_HASH_TABLE_CHAINS);
}

/** Compare hash table item with a key.
 *
 * @param key  Array containing the source phone hash as the only item.
 * @param keys Expected 1 but ignored.
 * @param item Connection hash table item.
 *
 * @return True on match, false otherwise.
 *
 */
static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
{
    connection_t *hs = hash_table_get_instance(item, connection_t, link);
    return (key[0] == hs->in_phone_hash);
}

/** Connection hash table removal callback function.
 *
 * This function is called whenever a connection is removed from the connection
 * hash table.
 *
 * @param item Connection hash table item being removed.
 *
 */
static void conn_remove(link_t *item)
{
    free(hash_table_get_instance(item, connection_t, link));
}


/** Operations for the connection hash table. */
static hash_table_operations_t conn_hash_table_ops = {
    .hash = conn_hash,
    .compare = conn_compare,
    .remove_callback = conn_remove
};

/** Sort in current fibril's timeout request.
 *
 * @param wd Wait data of the current fibril.
 *
 */
static void insert_timeout(awaiter_t *wd)
{
    wd->timedout = false;
    wd->inlist = true;
    
    link_t *tmp = timeout_list.next;
    while (tmp != &timeout_list) {
        awaiter_t *cur = list_get_instance(tmp, awaiter_t, link);
        
        if (tv_gteq(&cur->expires, &wd->expires))
            break;
        
        tmp = tmp->next;
    }
    
    list_append(&wd->link, tmp);
}

/** Try to route a call to an appropriate connection fibril.
 *
 * If the proper connection fibril is found, a message with the call is added to
 * its message queue. If the fibril was not active, it is activated and all
 * timeouts are unregistered.
 *
 * @param callid Hash of the incoming call.
 * @param call   Data of the incoming call.
 *
 * @return False if the call doesn't match any connection.
 *         True if the call was passed to the respective connection fibril.
 *
 */
static bool route_call(ipc_callid_t callid, ipc_call_t *call)
{
    futex_down(&async_futex);
    
    unsigned long key = call->in_phone_hash;
    link_t *hlp = hash_table_find(&conn_hash_table, &key);
    
    if (!hlp) {
        futex_up(&async_futex);
        return false;
    }
    
    connection_t *conn = hash_table_get_instance(hlp, connection_t, link);
    
    msg_t *msg = malloc(sizeof(*msg));
    if (!msg) {
        futex_up(&async_futex);
        return false;
    }
    
    msg->callid = callid;
    msg->call = *call;
    list_append(&msg->link, &conn->msg_queue);
    
    if (IPC_GET_METHOD(*call) == IPC_M_PHONE_HUNGUP)
        conn->close_callid = callid;
    
    /* If the connection fibril is waiting for an event, activate it */
    if (!conn->wdata.active) {
        
        /* If in timeout list, remove it */
        if (conn->wdata.inlist) {
            conn->wdata.inlist = false;
            list_remove(&conn->wdata.link);
        }
        
        conn->wdata.active = true;
        fibril_add_ready(conn->wdata.fid);
    }
    
    futex_up(&async_futex);
    return true;
}

/** Notification fibril.
 *
 * When a notification arrives, a fibril with this implementing function is
 * created. It calls interrupt_received() and does the final cleanup.
 *
 * @param arg Message structure pointer.
 *
 * @return Always zero.
 *
 */
static int notification_fibril(void *arg)
{
    msg_t *msg = (msg_t *) arg;
    interrupt_received(msg->callid, &msg->call);
    
    free(msg);
    return 0;
}

/** Process interrupt notification.
 *
 * A new fibril is created which would process the notification.
 *
 * @param callid Hash of the incoming call.
 * @param call   Data of the incoming call.
 *
 * @return False if an error occured.
 *         True if the call was passed to the notification fibril.
 *
 */
static bool process_notification(ipc_callid_t callid, ipc_call_t *call)
{
    futex_down(&async_futex);
    
    msg_t *msg = malloc(sizeof(*msg));
    if (!msg) {
        futex_up(&async_futex);
        return false;
    }
    
    msg->callid = callid;
    msg->call = *call;
    
    fid_t fid = fibril_create(notification_fibril, msg);
    fibril_add_ready(fid);
    
    futex_up(&async_futex);
    return true;
}

/** Return new incoming message for the current (fibril-local) connection.
 *
 * @param call  Storage where the incoming call data will be stored.
 * @param usecs Timeout in microseconds. Zero denotes no timeout.
 *
 * @return If no timeout was specified, then a hash of the
 *         incoming call is returned. If a timeout is specified,
 *         then a hash of the incoming call is returned unless
 *         the timeout expires prior to receiving a message. In
 *         that case zero is returned.
 *
 */
ipc_callid_t async_get_call_timeout(ipc_call_t *call, suseconds_t usecs)
{
    assert(FIBRIL_connection);
    
    /* Why doing this?
     * GCC 4.1.0 coughs on FIBRIL_connection-> dereference.
     * GCC 4.1.1 happilly puts the rdhwr instruction in delay slot.
     *           I would never expect to find so many errors in
     *           a compiler.
     */
    connection_t *conn = FIBRIL_connection;
    
    futex_down(&async_futex);
    
    if (usecs) {
        gettimeofday(&conn->wdata.expires, NULL);
        tv_add(&conn->wdata.expires, usecs);
    } else
        conn->wdata.inlist = false;
    
    /* If nothing in queue, wait until something arrives */
    while (list_empty(&conn->msg_queue)) {
        if (usecs)
            insert_timeout(&conn->wdata);
        
        conn->wdata.active = false;
        
        /*
         * Note: the current fibril will be rescheduled either due to a
         * timeout or due to an arriving message destined to it. In the
         * former case, handle_expired_timeouts() and, in the latter
         * case, route_call() will perform the wakeup.
         */
        fibril_switch(FIBRIL_TO_MANAGER);
        
        /*
         * Futex is up after getting back from async_manager.
         * Get it again.
         */
        futex_down(&async_futex);
        if ((usecs) && (conn->wdata.timedout)
            && (list_empty(&conn->msg_queue))) {
            /* If we timed out -> exit */
            futex_up(&async_futex);
            return 0;
        }
    }
    
    msg_t *msg = list_get_instance(conn->msg_queue.next, msg_t, link);
    list_remove(&msg->link);
    
    ipc_callid_t callid = msg->callid;
    *call = msg->call;
    free(msg);
    
    futex_up(&async_futex);
    return callid;
}

/** Default fibril function that gets called to handle new connection.
 *
 * This function is defined as a weak symbol - to be redefined in user code.
 *
 * @param callid Hash of the incoming call.
 * @param call   Data of the incoming call.
 *
 */
static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
{
    ipc_answer_0(callid, ENOENT);
}

/** Default fibril function that gets called to handle interrupt notifications.
 *
 * This function is defined as a weak symbol - to be redefined in user code.
 *
 * @param callid Hash of the incoming call.
 * @param call   Data of the incoming call.
 *
 */
static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call)
{
}

/** Wrapper for client connection fibril.
 *
 * When a new connection arrives, a fibril with this implementing function is
 * created. It calls client_connection() and does the final cleanup.
 *
 * @param arg Connection structure pointer.
 *
 * @return Always zero.
 *
 */
static int connection_fibril(void *arg)
{
    /*
     * Setup fibril-local connection pointer and call client_connection().
     *
     */
    FIBRIL_connection = (connection_t *) arg;
    FIBRIL_connection->cfibril(FIBRIL_connection->callid,
        &FIBRIL_connection->call);
    
    /* Remove myself from the connection hash table */
    futex_down(&async_futex);
    unsigned long key = FIBRIL_connection->in_phone_hash;
    hash_table_remove(&conn_hash_table, &key, 1);
    futex_up(&async_futex);
    
    /* Answer all remaining messages with EHANGUP */
    while (!list_empty(&FIBRIL_connection->msg_queue)) {
        msg_t *msg;
        
        msg = list_get_instance(FIBRIL_connection->msg_queue.next,
            msg_t, link);
        list_remove(&msg->link);
        ipc_answer_0(msg->callid, EHANGUP);
        free(msg);
    }
    
    if (FIBRIL_connection->close_callid)
        ipc_answer_0(FIBRIL_connection->close_callid, EOK);
    
    return 0;
}

/** Create a new fibril for a new connection.
 *
 * Create new fibril for connection, fill in connection structures and inserts
 * it into the hash table, so that later we can easily do routing of messages to
 * particular fibrils.
 *
 * @param in_phone_hash Identification of the incoming connection.
 * @param callid        Hash of the opening IPC_M_CONNECT_ME_TO call.
 *                      If callid is zero, the connection was opened by
 *                      accepting the IPC_M_CONNECT_TO_ME call and this function
 *                      is called directly by the server.
 * @param call          Call data of the opening call.
 * @param cfibril       Fibril function that should be called upon opening the
 *                      connection.
 *
 * @return New fibril id or NULL on failure.
 *
 */
fid_t async_new_connection(ipcarg_t in_phone_hash, ipc_callid_t callid,
    ipc_call_t *call, void (*cfibril)(ipc_callid_t, ipc_call_t *))
{
    connection_t *conn = malloc(sizeof(*conn));
    if (!conn) {
        if (callid)
            ipc_answer_0(callid, ENOMEM);
        return NULL;
    }
    
    conn->in_phone_hash = in_phone_hash;
    list_initialize(&conn->msg_queue);
    conn->callid = callid;
    conn->close_callid = false;
    
    if (call)
        conn->call = *call;
    
    /* We will activate the fibril ASAP */
    conn->wdata.active = true;
    conn->cfibril = cfibril;
    conn->wdata.fid = fibril_create(connection_fibril, conn);
    
    if (!conn->wdata.fid) {
        free(conn);
        if (callid)
            ipc_answer_0(callid, ENOMEM);
        return NULL;
    }
    
    /* Add connection to the connection hash table */
    unsigned long key = conn->in_phone_hash;
    
    futex_down(&async_futex);
    hash_table_insert(&conn_hash_table, &key, &conn->link);
    futex_up(&async_futex);
    
    fibril_add_ready(conn->wdata.fid);
    
    return conn->wdata.fid;
}

/** Handle a call that was received.
 *
 * If the call has the IPC_M_CONNECT_ME_TO method, a new connection is created.
 * Otherwise the call is routed to its connection fibril.
 *
 * @param callid Hash of the incoming call.
 * @param call   Data of the incoming call.
 *
 */
static void handle_call(ipc_callid_t callid, ipc_call_t *call)
{
    /* Unrouted call - do some default behaviour */
    if ((callid & IPC_CALLID_NOTIFICATION)) {
        process_notification(callid, call);
        goto out;
    }
    
    switch (IPC_GET_METHOD(*call)) {
    case IPC_M_CONNECT_ME:
    case IPC_M_CONNECT_ME_TO:
        /* Open new connection with fibril etc. */
        async_new_connection(IPC_GET_ARG5(*call), callid, call,
            client_connection);
        goto out;
    }
    
    /* Try to route the call through the connection hash table */
    if (route_call(callid, call))
        goto out;
    
    /* Unknown call from unknown phone - hang it up */
    ipc_answer_0(callid, EHANGUP);
    return;
    
out:
    ;
}

/** Fire all timeouts that expired. */
static void handle_expired_timeouts(void)
{
    struct timeval tv;
    gettimeofday(&tv, NULL);
    
    futex_down(&async_futex);
    
    link_t *cur = timeout_list.next;
    while (cur != &timeout_list) {
        awaiter_t *waiter = list_get_instance(cur, awaiter_t, link);
        
        if (tv_gt(&waiter->expires, &tv))
            break;
        
        cur = cur->next;
        
        list_remove(&waiter->link);
        waiter->inlist = false;
        waiter->timedout = true;
        
        /*
         * Redundant condition?
         * The fibril should not be active when it gets here.
         */
        if (!waiter->active) {
            waiter->active = true;
            fibril_add_ready(waiter->fid);
        }
    }
    
    futex_up(&async_futex);
}

/** Endless loop dispatching incoming calls and answers.
 *
 * @return Never returns.
 *
 */
static int async_manager_worker(void)
{
    while (true) {
        if (fibril_switch(FIBRIL_FROM_MANAGER)) {
            futex_up(&async_futex); 
            /*
             * async_futex is always held when entering a manager
             * fibril.
             */
            continue;
        }
        
        futex_down(&async_futex);
        
        suseconds_t timeout;
        if (!list_empty(&timeout_list)) {
            awaiter_t *waiter = list_get_instance(timeout_list.next,
                awaiter_t, link);
            
            struct timeval tv;
            gettimeofday(&tv, NULL);
            
            if (tv_gteq(&tv, &waiter->expires)) {
                futex_up(&async_futex);
                handle_expired_timeouts();
                continue;
            } else
                timeout = tv_sub(&waiter->expires, &tv);
        } else
            timeout = SYNCH_NO_TIMEOUT;
        
        futex_up(&async_futex);
        
        ipc_call_t call;
        ipc_callid_t callid = ipc_wait_cycle(&call, timeout,
            SYNCH_FLAGS_NONE);
        
        if (!callid) {
            handle_expired_timeouts();
            continue;
        }
        
        if (callid & IPC_CALLID_ANSWERED)
            continue;
        
        handle_call(callid, &call);
    }
    
    return 0;
}

/** Function to start async_manager as a standalone fibril.
 *
 * When more kernel threads are used, one async manager should exist per thread.
 *
 * @param arg Unused.
 * @return Never returns.
 *
 */
static int async_manager_fibril(void *arg)
{
    futex_up(&async_futex);
    
    /*
     * async_futex is always locked when entering manager
     */
    async_manager_worker();
    
    return 0;
}

/** Add one manager to manager list. */
void async_create_manager(void)
{
    fid_t fid = fibril_create(async_manager_fibril, NULL);
    fibril_add_manager(fid);
}

/** Remove one manager from manager list */
void async_destroy_manager(void)
{
    fibril_remove_manager();
}

/** Initialize the async framework.
 *
 * @return Zero on success or an error code.
 */
int __async_init(void)
{
    if (!hash_table_create(&conn_hash_table, CONN_HASH_TABLE_CHAINS, 1,
        &conn_hash_table_ops)) {
        printf("%s: cannot create hash table\n", "async");
        return ENOMEM;
    }
    
    return 0;
}

/** Reply received callback.
 *
 * This function is called whenever a reply for an asynchronous message sent out
 * by the asynchronous framework is received.
 *
 * Notify the fibril which is waiting for this message that it has arrived.
 *
 * @param arg    Pointer to the asynchronous message record.
 * @param retval Value returned in the answer.
 * @param data   Call data of the answer.
 */
static void reply_received(void *arg, int retval, ipc_call_t *data)
{
    futex_down(&async_futex);
    
    amsg_t *msg = (amsg_t *) arg;
    msg->retval = retval;
    
    /* Copy data after futex_down, just in case the call was detached */
    if ((msg->dataptr) && (data))
        *msg->dataptr = *data;
    
    write_barrier();
    
    /* Remove message from timeout list */
    if (msg->wdata.inlist)
        list_remove(&msg->wdata.link);
    
    msg->done = true;
    if (!msg->wdata.active) {
        msg->wdata.active = true;
        fibril_add_ready(msg->wdata.fid);
    }
    
    futex_up(&async_futex);
}

/** Send message and return id of the sent message.
 *
 * The return value can be used as input for async_wait() to wait for
 * completion.
 *
 * @param phoneid Handle of the phone that will be used for the send.
 * @param method  Service-defined method.
 * @param arg1    Service-defined payload argument.
 * @param arg2    Service-defined payload argument.
 * @param arg3    Service-defined payload argument.
 * @param arg4    Service-defined payload argument.
 * @param dataptr If non-NULL, storage where the reply data will be
 *                stored.
 *
 * @return Hash of the sent message or 0 on error.
 *
 */
aid_t async_send_fast(int phoneid, ipcarg_t method, ipcarg_t arg1,
    ipcarg_t arg2, ipcarg_t arg3, ipcarg_t arg4, ipc_call_t *dataptr)
{
    amsg_t *msg = malloc(sizeof(*msg));
    
    if (!msg)
        return 0;
    
    msg->done = false;
    msg->dataptr = dataptr;
    
    msg->wdata.inlist = false;
    /* We may sleep in the next method, but it will use its own mechanism */
    msg->wdata.active = true;
    
    ipc_call_async_4(phoneid, method, arg1, arg2, arg3, arg4, msg,
        reply_received, true);
    
    return (aid_t) msg;
}

/** Send message and return id of the sent message
 *
 * The return value can be used as input for async_wait() to wait for
 * completion.
 *
 * @param phoneid Handle of the phone that will be used for the send.
 * @param method  Service-defined method.
 * @param arg1    Service-defined payload argument.
 * @param arg2    Service-defined payload argument.
 * @param arg3    Service-defined payload argument.
 * @param arg4    Service-defined payload argument.
 * @param arg5    Service-defined payload argument.
 * @param dataptr If non-NULL, storage where the reply data will be
 *                stored.
 *
 * @return Hash of the sent message or 0 on error.
 *
 */
aid_t async_send_slow(int phoneid, ipcarg_t method, ipcarg_t arg1,
    ipcarg_t arg2, ipcarg_t arg3, ipcarg_t arg4, ipcarg_t arg5,
    ipc_call_t *dataptr)
{
    amsg_t *msg = malloc(sizeof(*msg));
    
    if (!msg)
        return 0;
    
    msg->done = false;
    msg->dataptr = dataptr;
    
    msg->wdata.inlist = false;
    /* We may sleep in next method, but it will use its own mechanism */
    msg->wdata.active = true;
    
    ipc_call_async_5(phoneid, method, arg1, arg2, arg3, arg4, arg5, msg,
        reply_received, true);
    
    return (aid_t) msg;
}

/** Wait for a message sent by the async framework.
 *
 * @param amsgid Hash of the message to wait for.
 * @param retval Pointer to storage where the retval of the answer will
 *               be stored.
 *
 */
void async_wait_for(aid_t amsgid, ipcarg_t *retval)
{
    amsg_t *msg = (amsg_t *) amsgid;
    
    futex_down(&async_futex);
    if (msg->done) {
        futex_up(&async_futex);
        goto done;
    }
    
    msg->wdata.fid = fibril_get_id();
    msg->wdata.active = false;
    msg->wdata.inlist = false;
    
    /* Leave the async_futex locked when entering this function */
    fibril_switch(FIBRIL_TO_MANAGER);
    
    /* Futex is up automatically after fibril_switch */
    
done:
    if (retval)
        *retval = msg->retval;
    
    free(msg);
}

/** Wait for a message sent by the async framework, timeout variant.
 *
 * @param amsgid  Hash of the message to wait for.
 * @param retval  Pointer to storage where the retval of the answer will
 *                be stored.
 * @param timeout Timeout in microseconds.
 *
 * @return Zero on success, ETIMEOUT if the timeout has expired.
 *
 */
int async_wait_timeout(aid_t amsgid, ipcarg_t *retval, suseconds_t timeout)
{
    amsg_t *msg = (amsg_t *) amsgid;
    
    /* TODO: Let it go through the event read at least once */
    if (timeout < 0)
        return ETIMEOUT;
    
    futex_down(&async_futex);
    if (msg->done) {
        futex_up(&async_futex);
        goto done;
    }
    
    gettimeofday(&msg->wdata.expires, NULL);
    tv_add(&msg->wdata.expires, timeout);
    
    msg->wdata.fid = fibril_get_id();
    msg->wdata.active = false;
    insert_timeout(&msg->wdata);
    
    /* Leave the async_futex locked when entering this function */
    fibril_switch(FIBRIL_TO_MANAGER);
    
    /* Futex is up automatically after fibril_switch */
    
    if (!msg->done)
        return ETIMEOUT;
    
done:
    if (retval)
        *retval = msg->retval;
    
    free(msg);
    
    return 0;
}

/** Wait for specified time.
 *
 * The current fibril is suspended but the thread continues to execute.
 *
 * @param timeout Duration of the wait in microseconds.
 *
 */
void async_usleep(suseconds_t timeout)
{
    amsg_t *msg = malloc(sizeof(*msg));
    
    if (!msg)
        return;
    
    msg->wdata.fid = fibril_get_id();
    msg->wdata.active = false;
    
    gettimeofday(&msg->wdata.expires, NULL);
    tv_add(&msg->wdata.expires, timeout);
    
    futex_down(&async_futex);
    
    insert_timeout(&msg->wdata);
    
    /* Leave the async_futex locked when entering this function */
    fibril_switch(FIBRIL_TO_MANAGER);
    
    /* Futex is up automatically after fibril_switch() */
    
    free(msg);
}

/** Setter for client_connection function pointer.
 *
 * @param conn Function that will implement a new connection fibril.
 *
 */
void async_set_client_connection(async_client_conn_t conn)
{
    client_connection = conn;
}

/** Setter for interrupt_received function pointer.
 *
 * @param intr Function that will implement a new interrupt
 *             notification fibril.
 */
void async_set_interrupt_received(async_client_conn_t intr)
{
    interrupt_received = intr;
}

/** Pseudo-synchronous message sending - fast version.
 *
 * Send message asynchronously and return only after the reply arrives.
 *
 * This function can only transfer 4 register payload arguments. For
 * transferring more arguments, see the slower async_req_slow().
 *
 * @param phoneid Hash of the phone through which to make the call.
 * @param method  Method of the call.
 * @param arg1    Service-defined payload argument.
 * @param arg2    Service-defined payload argument.
 * @param arg3    Service-defined payload argument.
 * @param arg4    Service-defined payload argument.
 * @param r1      If non-NULL, storage for the 1st reply argument.
 * @param r2      If non-NULL, storage for the 2nd reply argument.
 * @param r3      If non-NULL, storage for the 3rd reply argument.
 * @param r4      If non-NULL, storage for the 4th reply argument.
 * @param r5      If non-NULL, storage for the 5th reply argument.
 *
 * @return Return code of the reply or a negative error code.
 *
 */
ipcarg_t async_req_fast(int phoneid, ipcarg_t method, ipcarg_t arg1,
    ipcarg_t arg2, ipcarg_t arg3, ipcarg_t arg4, ipcarg_t *r1, ipcarg_t *r2,
    ipcarg_t *r3, ipcarg_t *r4, ipcarg_t *r5)
{
    ipc_call_t result;
    aid_t eid = async_send_4(phoneid, method, arg1, arg2, arg3, arg4,
        &result);
    
    ipcarg_t rc;
    async_wait_for(eid, &rc);
    
    if (r1)
        *r1 = IPC_GET_ARG1(result);
    
    if (r2)
        *r2 = IPC_GET_ARG2(result);
    
    if (r3)
        *r3 = IPC_GET_ARG3(result);
    
    if (r4)
        *r4 = IPC_GET_ARG4(result);
    
    if (r5)
        *r5 = IPC_GET_ARG5(result);
    
    return rc;
}

/** Pseudo-synchronous message sending - slow version.
 *
 * Send message asynchronously and return only after the reply arrives.
 *
 * @param phoneid Hash of the phone through which to make the call.
 * @param method  Method of the call.
 * @param arg1    Service-defined payload argument.
 * @param arg2    Service-defined payload argument.
 * @param arg3    Service-defined payload argument.
 * @param arg4    Service-defined payload argument.
 * @param arg5    Service-defined payload argument.
 * @param r1      If non-NULL, storage for the 1st reply argument.
 * @param r2      If non-NULL, storage for the 2nd reply argument.
 * @param r3      If non-NULL, storage for the 3rd reply argument.
 * @param r4      If non-NULL, storage for the 4th reply argument.
 * @param r5      If non-NULL, storage for the 5th reply argument.
 *
 * @return Return code of the reply or a negative error code.
 *
 */
ipcarg_t async_req_slow(int phoneid, ipcarg_t method, ipcarg_t arg1,
    ipcarg_t arg2, ipcarg_t arg3, ipcarg_t arg4, ipcarg_t arg5, ipcarg_t *r1,
    ipcarg_t *r2, ipcarg_t *r3, ipcarg_t *r4, ipcarg_t *r5)
{
    ipc_call_t result;
    aid_t eid = async_send_5(phoneid, method, arg1, arg2, arg3, arg4, arg5,
        &result);
    
    ipcarg_t rc;
    async_wait_for(eid, &rc);
    
    if (r1)
        *r1 = IPC_GET_ARG1(result);
    
    if (r2)
        *r2 = IPC_GET_ARG2(result);
    
    if (r3)
        *r3 = IPC_GET_ARG3(result);
    
    if (r4)
        *r4 = IPC_GET_ARG4(result);
    
    if (r5)
        *r5 = IPC_GET_ARG5(result);
    
    return rc;
}

/** @}
 */