WebSVN – HelenOS-historic – Diff – /uspace/trunk/libc/generic/async.c


/*
 * 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.
 */
 
/**
 * Asynchronous library
 *
 * The aim of this library is facilitating writing programs utilizing
 * 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:
 * - 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:
 *
 * 1) Multithreaded client application
 *  create_thread(thread1);
 *  create_thread(thread2);
 *  ...
 *  
 *  thread1() {
 *        conn = ipc_connect_me_to();
 *        c1 = send(conn);
 *        c2 = send(conn);
 *        wait_for(c1);
 *        wait_for(c2);
 *  }
 *
 *
 * 2) Multithreaded server application
 * main() {
 *      async_manager();
 * }
 *
 *
 * client_connection(icallid, *icall) {
 *       if (want_refuse) {
 *           ipc_answer_fast(icallid, ELIMIT, 0, 0);
 *           return;
 *       }
 *       ipc_answer_fast(icallid, 0, 0, 0);
 *
 *       callid = async_get_call(&call);
 *       handle(callid, call);
 *       ipc_answer_fast(callid, 1,2,3);
 *
 *       callid = async_get_call(&call);
 *       ....
 * }
 *
 * TODO: Detaching/joining dead psthreads?
 */
#include <futex.h>
#include <async.h>
#include <psthread.h>
#include <stdio.h>
#include <libadt/hash_table.h>
#include <libadt/list.h>
#include <ipc/ipc.h>
#include <assert.h>
#include <errno.h>
#include <time.h>
#include <arch/barrier.h>
 
atomic_t async_futex = FUTEX_INITIALIZER;
static hash_table_t conn_hash_table;
static LIST_INITIALIZE(timeout_list);
 
typedef struct {
    struct timeval expires;      /**< Expiration time for waiting thread */
    int inlist;             /**< If true, this struct is in timeout list */
    link_t link;
 
    pstid_t ptid;                /**< Thread waiting for this message */
    int active;                  /**< If this thread is currently active */
    int timedout;                /**< If true, we timed out */
} awaiter_t;
 
typedef struct {
    awaiter_t wdata;
 
    int done;                    /**< If reply was received */
    ipc_call_t *dataptr;         /**< Pointer where the answer data
                      *   is stored */
    ipcarg_t retval;
} amsg_t;
 
typedef struct {
    link_t link;
    ipc_callid_t callid;
    ipc_call_t call;
} msg_t;
 
typedef struct {
    awaiter_t wdata;
 
    link_t link;             /**< Hash table link */
    ipcarg_t in_phone_hash;  /**< Incoming phone hash. */
    link_t msg_queue;        /**< Messages that should be delivered to this thread */
    /* Structures for connection opening packet */
    ipc_callid_t callid;
    ipc_call_t call;
    void (*cthread)(ipc_callid_t,ipc_call_t *);
} connection_t;
 
/** Identifier of incoming connection handled by current thread */
__thread connection_t *PS_connection;
/** If true, it is forbidden to use async_req functions and
 *  all preemption is disabled */
__thread int in_interrupt_handler;
 
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);
static async_client_conn_t client_connection = default_client_connection;
static async_client_conn_t interrupt_received = default_interrupt_received;
 
/** Add microseconds to give timeval */
static void tv_add(struct timeval *tv, suseconds_t usecs)
{
    tv->tv_sec += usecs / 1000000;
    tv->tv_usec += usecs % 1000000;
    if (tv->tv_usec > 1000000) {
        tv->tv_sec++;
        tv->tv_usec -= 1000000;
    }
}
 
/** Subtract 2 timevals, return microseconds difference */
static suseconds_t tv_sub(struct timeval *tv1, struct timeval *tv2)
{
    suseconds_t result;
 
    result = tv1->tv_usec - tv2->tv_usec;
    result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
 
    return result;
}
 
/** Compare timeval
 *
 * @return 1 if tv1 > tv2, otherwise 0
 */
static int tv_gt(struct timeval *tv1, struct timeval *tv2)
{
    if (tv1->tv_sec > tv2->tv_sec)
        return 1;
    if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
        return 1;
    return 0;
}
static int tv_gteq(struct timeval *tv1, struct timeval *tv2)
{
    if (tv1->tv_sec > tv2->tv_sec)
        return 1;
    if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
        return 1;
    return 0;
}
 
/* Hash table functions */
#define CONN_HASH_TABLE_CHAINS  32
 
static hash_index_t conn_hash(unsigned long *key)
{
    assert(key);
    return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
}
 
static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
{
    connection_t *hs;
 
    hs = hash_table_get_instance(item, connection_t, link);
   
    return key[0] == hs->in_phone_hash;
}
 
static void conn_remove(link_t *item)
{
    free(hash_table_get_instance(item, connection_t, link));
}
 
 
/** Operations for NS hash table. */
static hash_table_operations_t conn_hash_table_ops = {
    .hash = conn_hash,
    .compare = conn_compare,
    .remove_callback = conn_remove
};
 
/** Insert sort timeout msg into timeouts list
 *
 */
static void insert_timeout(awaiter_t *wd)
{
    link_t *tmp;
    awaiter_t *cur;
 
    wd->timedout = 0;
    wd->inlist = 1;
 
    tmp = timeout_list.next;
    while (tmp != &timeout_list) {
        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 thread
 *
 */
static int route_call(ipc_callid_t callid, ipc_call_t *call)
{
    connection_t *conn;
    msg_t *msg;
    link_t *hlp;
    unsigned long key;
 
    futex_down(&async_futex);
 
    key = call->in_phone_hash;
    hlp = hash_table_find(&conn_hash_table, &key);
    if (!hlp) {
        futex_up(&async_futex);
        return 0;
    }
    conn = hash_table_get_instance(hlp, connection_t, link);
 
    msg = malloc(sizeof(*msg));
    msg->callid = callid;
    msg->call = *call;
    list_append(&msg->link, &conn->msg_queue);
   
    /* If the call is waiting for event, run it */
    if (!conn->wdata.active) {
        /* If in timeout list, remove it */
        if (conn->wdata.inlist) {
            conn->wdata.inlist = 0;
            list_remove(&conn->wdata.link);
        }
        conn->wdata.active = 1;
        psthread_add_ready(conn->wdata.ptid);
    }
 
    futex_up(&async_futex);
 
    return 1;
}
 
/** Return new incoming message for current(thread-local) connection */
ipc_callid_t async_get_call_timeout(ipc_call_t *call, suseconds_t usecs)
{
    msg_t *msg;
    ipc_callid_t callid;
    connection_t *conn;
   
    assert(PS_connection);
    /* GCC 4.1.0 coughs on PS_connection-> dereference,
     * GCC 4.1.1 happilly puts the rdhwr instruction in delay slot.
     *           I would never expect to find so many errors in
     *           compiler *($&$(*&$
     */
    conn = PS_connection;
 
    futex_down(&async_futex);
 
    if (usecs) {
        gettimeofday(&conn->wdata.expires, NULL);
        tv_add(&conn->wdata.expires, usecs);
    } else {
        conn->wdata.inlist = 0;
    }
    /* If nothing in queue, wait until something appears */
    while (list_empty(&conn->msg_queue)) {
        if (usecs)
            insert_timeout(&conn->wdata);
 
        conn->wdata.active = 0;
        psthread_schedule_next_adv(PS_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 = list_get_instance(conn->msg_queue.next, msg_t, link);
    list_remove(&msg->link);
    callid = msg->callid;
    *call = msg->call;
    free(msg);
   
    futex_up(&async_futex);
    return callid;
}
 
/** Thread function that gets created on new connection
 *
 * This function is defined as a weak symbol - to be redefined in
 * user code.
 */
static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
{
    ipc_answer_fast(callid, ENOENT, 0, 0);
}
static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call)
{
}
 
/** Wrapper for client connection thread
 *
 * When new connection arrives, thread with this function is created.
 * It calls client_connection and does final cleanup.
 *
 * @parameter arg Connection structure pointer
 */
static int connection_thread(void  *arg)
{
    unsigned long key;
    msg_t *msg;
 
    /* Setup thread local connection pointer */
    PS_connection = (connection_t *)arg;
    PS_connection->cthread(PS_connection->callid, &PS_connection->call);
    /* Remove myself from connection hash table */
    futex_down(&async_futex);
    key = PS_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(&PS_connection->msg_queue)) {
        msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
        list_remove(&msg->link);
        ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
        free(msg);
    }
}
 
/** Create new thread for a new connection
 *
 * Creates new thread for connection, fills in connection
 * structures and inserts it into the hash table, so that
 * later we can easily do routing of messages to particular
 * threads.
 *
 * @param in_phone_hash Identification of the incoming connection
 * @param callid Callid of the IPC_M_CONNECT_ME_TO packet
 * @param call Call data of the opening packet
 * @param cthread Thread function that should be called upon
 *                opening the connection
 * @return New thread id
 */
pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,
                 ipc_call_t *call,
                 void (*cthread)(ipc_callid_t,ipc_call_t *))
{
    pstid_t ptid;
    connection_t *conn;
    unsigned long key;
 
    conn = malloc(sizeof(*conn));
    if (!conn) {
        ipc_answer_fast(callid, ENOMEM, 0, 0);
        return NULL;
    }
    conn->in_phone_hash = in_phone_hash;
    list_initialize(&conn->msg_queue);
    conn->callid = callid;
    if (call)
        conn->call = *call;
    conn->wdata.active = 1; /* We will activate it asap */
    conn->cthread = cthread;
 
    conn->wdata.ptid = psthread_create(connection_thread, conn);
    if (!conn->wdata.ptid) {
        free(conn);
        ipc_answer_fast(callid, ENOMEM, 0, 0);
        return NULL;
    }
    /* Add connection to hash table */
    key = conn->in_phone_hash;
    futex_down(&async_futex);
    hash_table_insert(&conn_hash_table, &key, &conn->link);
    futex_up(&async_futex);
 
    psthread_add_ready(conn->wdata.ptid);
 
    return conn->wdata.ptid;
}
 
/** Handle call that was received */
static void handle_call(ipc_callid_t callid, ipc_call_t *call)
{
    /* Unrouted call - do some default behaviour */
    switch (IPC_GET_METHOD(*call)) {
    case IPC_M_INTERRUPT:
        in_interrupt_handler = 1;
        (*interrupt_received)(callid,call);
        in_interrupt_handler = 0;
        return;
    case IPC_M_CONNECT_ME_TO:
        /* Open new connection with thread etc. */
        async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
        return;
    }
 
    /* Try to route call through connection tables */
    if (route_call(callid, call))
        return;
 
    /* Unknown call from unknown phone - hang it up */
    ipc_answer_fast(callid, EHANGUP, 0, 0);
}
 
/** Fire all timeouts that expired
 *
 */
static void handle_expired_timeouts(void)
{
    struct timeval tv;
    awaiter_t *waiter;
    link_t *cur;
 
    gettimeofday(&tv,NULL);
    futex_down(&async_futex);
 
    cur = timeout_list.next;
    while (cur != &timeout_list) {
        waiter = list_get_instance(cur,awaiter_t,link);
        if (tv_gt(&waiter->expires, &tv))
            break;
        cur = cur->next;
        list_remove(&waiter->link);
        waiter->inlist = 0;
        waiter->timedout = 1;
        /* Redundant condition? The thread should not
         * be active when it gets here.
         */
        if (!waiter->active) {
            waiter->active = 1;
            psthread_add_ready(waiter->ptid);
        }
    }
 
    futex_up(&async_futex);
}
 
/** Endless loop dispatching incoming calls and answers */
static int async_manager_worker(void)
{
    ipc_call_t call;
    ipc_callid_t callid;
    int timeout;
    awaiter_t *waiter;
    struct timeval tv;
 
    while (1) {
        if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
            futex_up(&async_futex); /* async_futex is always held
                        * when entering manager thread
                        */
            continue;
        }
        futex_down(&async_futex);
        if (!list_empty(&timeout_list)) {
            waiter = list_get_instance(timeout_list.next,awaiter_t,link);
            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);
 
        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);
    }
}
 
/** Function to start async_manager as a standalone thread
 *
 * When more kernel threads are used, one async manager should
 * exist per thread. The particular implementation may change,
 * currently one async_manager is started automatically per kernel
 * thread except main thread.
 */
static int async_manager_thread(void *arg)
{
 
    futex_up(&async_futex); /* async_futex is always locked when entering
                * manager */
    async_manager_worker();
}
 
/** Add one manager to manager list */
void async_create_manager(void)
{
    pstid_t ptid;
 
    ptid = psthread_create(async_manager_thread, NULL);
    psthread_add_manager(ptid);
}
 
/** Remove one manager from manager list */
void async_destroy_manager(void)
{
    psthread_remove_manager();
}
 
/** Initialize internal structures needed for async manager */
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;
    }
   
}
 
/** IPC handler for messages in async framework
 *
 * Notify thread that is waiting for this message, that it arrived
 */
static void reply_received(void *private, int retval,
               ipc_call_t *data)
{
    amsg_t *msg = (amsg_t *) private;
 
    msg->retval = retval;
 
    futex_down(&async_futex);
    /* Copy data after futex_down, just in case the
     * call was detached
     */
    if (msg->dataptr)
        *msg->dataptr = *data;
 
    write_barrier();
    /* Remove message from timeout list */
    if (msg->wdata.inlist)
        list_remove(&msg->wdata.link);
    msg->done = 1;
    if (! msg->wdata.active) {
        msg->wdata.active = 1;
        psthread_add_ready(msg->wdata.ptid);
    }
    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.
 */
aid_t async_send_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
           ipc_call_t *dataptr)
{
    amsg_t *msg;
 
    if (in_interrupt_handler) {
        printf("Cannot send asynchronou request in interrupt handler.\n");
        _exit(1);
    }
 
    msg = malloc(sizeof(*msg));
    msg->done = 0;
    msg->dataptr = dataptr;
 
    msg->wdata.active = 1; /* We may sleep in next method, but it
                * will use it's own mechanism */
    ipc_call_async_2(phoneid,method,arg1,arg2,msg,reply_received,1);
 
    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.
 */
aid_t async_send_3(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
           ipcarg_t arg3, ipc_call_t *dataptr)
{
    amsg_t *msg;
 
    if (in_interrupt_handler) {
        printf("Cannot send asynchronou request in interrupt handler.\n");
        _exit(1);
    }
 
    msg = malloc(sizeof(*msg));
    msg->done = 0;
    msg->dataptr = dataptr;
 
    msg->wdata.active = 1; /* We may sleep in next method, but it
                * will use it's own mechanism */
    ipc_call_async_3(phoneid,method,arg1,arg2,arg3, msg,reply_received,1);
 
    return (aid_t) msg;
}
 
/** Wait for a message sent by async framework
 *
 * @param amsgid Message ID to wait for
 * @param retval Pointer to variable where will be stored retval
 *               of the answered message. If NULL, it is ignored.
 *
 */
void async_wait_for(aid_t amsgid, ipcarg_t *retval)
{
    amsg_t *msg = (amsg_t *) amsgid;
    connection_t *conn;
 
    futex_down(&async_futex);
    if (msg->done) {
        futex_up(&async_futex);
        goto done;
    }
 
    msg->wdata.ptid = psthread_get_id();
    msg->wdata.active = 0;
    msg->wdata.inlist = 0;
    /* Leave locked async_futex when entering this function */
    psthread_schedule_next_adv(PS_TO_MANAGER);
    /* futex is up automatically after psthread_schedule_next...*/
done:
    if (retval)
        *retval = msg->retval;
    free(msg);
}
 
/** Wait for a message sent by async framework with timeout
 *
 * @param amsgid Message ID to wait for
 * @param retval Pointer to variable where will be stored retval
 *               of the answered message. If NULL, it is ignored.
 * @param timeout Timeout in usecs
 * @return 0 on success, ETIMEOUT if timeout expired
 *
 */
int async_wait_timeout(aid_t amsgid, ipcarg_t *retval, suseconds_t timeout)
{
    amsg_t *msg = (amsg_t *) amsgid;
    connection_t *conn;
 
    /* 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.ptid = psthread_get_id();
    msg->wdata.active = 0;
    insert_timeout(&msg->wdata);
 
    /* Leave locked async_futex when entering this function */
    psthread_schedule_next_adv(PS_TO_MANAGER);
    /* futex is up automatically after psthread_schedule_next...*/
 
    if (!msg->done)
        return ETIMEOUT;
 
done:
    if (retval)
        *retval = msg->retval;
    free(msg);
 
    return 0;
}
 
/** Wait specified time, but in the meantime handle incoming events
 *
 * @param timeout Time in microseconds to wait
 */
void async_usleep(suseconds_t timeout)
{
    amsg_t *msg;
   
    if (in_interrupt_handler) {
        printf("Cannot call async_usleep in interrupt handler.\n");
        _exit(1);
    }
 
    msg = malloc(sizeof(*msg));
    if (!msg)
        return;
 
    msg->wdata.ptid = psthread_get_id();
    msg->wdata.active = 0;
 
    gettimeofday(&msg->wdata.expires, NULL);
    tv_add(&msg->wdata.expires, timeout);
 
    futex_down(&async_futex);
    insert_timeout(&msg->wdata);
    /* Leave locked async_futex when entering this function */
    psthread_schedule_next_adv(PS_TO_MANAGER);
    /* futex is up automatically after psthread_schedule_next...*/
    free(msg);
}
 
/** Set function that is called, IPC_M_CONNECT_ME_TO is received
 *
 * @param conn Function that will form new psthread.
 */
void async_set_client_connection(async_client_conn_t conn)
{
    client_connection = conn;
}
void async_set_interrupt_received(async_client_conn_t conn)
{
    interrupt_received = conn;
}
 
/* Primitive functions for simple communication */
void async_msg_3(int phoneid, ipcarg_t method, ipcarg_t arg1,
         ipcarg_t arg2, ipcarg_t arg3)
{
    ipc_call_async_3(phoneid, method, arg1, arg2, arg3, NULL, NULL, !in_interrupt_handler);
}
 
void async_msg_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2)
{
    ipc_call_async_2(phoneid, method, arg1, arg2, NULL, NULL, !in_interrupt_handler);
}
 

Rev 1610	Rev 1614
1	/*	1	/*
2	* Copyright (C) 2006 Ondrej Palkovsky	2	* Copyright (C) 2006 Ondrej Palkovsky
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/**	29	/**
30	* Asynchronous library	30	* Asynchronous library
31	*	31	*
32	* The aim of this library is facilitating writing programs utilizing	32	* The aim of this library is facilitating writing programs utilizing
33	* the asynchronous nature of Helenos IPC, yet using a normal way	33	* the asynchronous nature of Helenos IPC, yet using a normal way
34	* of programming.	34	* of programming.
35	*	35	*
36	* You should be able to write very simple multithreaded programs,	36	* You should be able to write very simple multithreaded programs,
37	* the async framework will automatically take care of most synchronization	37	* the async framework will automatically take care of most synchronization
38	* problems.	38	* problems.
39	*	39	*
40	* Default semantics:	40	* Default semantics:
41	* - send() - send asynchronously. If the kernel refuses to send more	41	* - send() - send asynchronously. If the kernel refuses to send more
42	* messages, [ try to get responses from kernel, if nothing	42	* messages, [ try to get responses from kernel, if nothing
43	* found, might try synchronous ]	43	* found, might try synchronous ]
44	*	44	*
45	* Example of use:	45	* Example of use:
46	*	46	*
47	* 1) Multithreaded client application	47	* 1) Multithreaded client application
48	* create_thread(thread1);	48	* create_thread(thread1);
49	* create_thread(thread2);	49	* create_thread(thread2);
50	* ...	50	* ...
51	*	51	*
52	* thread1() {	52	* thread1() {
53	* conn = ipc_connect_me_to();	53	* conn = ipc_connect_me_to();
54	* c1 = send(conn);	54	* c1 = send(conn);
55	* c2 = send(conn);	55	* c2 = send(conn);
56	* wait_for(c1);	56	* wait_for(c1);
57	* wait_for(c2);	57	* wait_for(c2);
58	* }	58	* }
59	*	59	*
60	*	60	*
61	* 2) Multithreaded server application	61	* 2) Multithreaded server application
62	* main() {	62	* main() {
63	* async_manager();	63	* async_manager();
64	* }	64	* }
65	*	65	*
66	*	66	*
67	* client_connection(icallid, *icall) {	67	* client_connection(icallid, *icall) {
68	* if (want_refuse) {	68	* if (want_refuse) {
69	* ipc_answer_fast(icallid, ELIMIT, 0, 0);	69	* ipc_answer_fast(icallid, ELIMIT, 0, 0);
70	* return;	70	* return;
71	* }	71	* }
72	* ipc_answer_fast(icallid, 0, 0, 0);	72	* ipc_answer_fast(icallid, 0, 0, 0);
73	*	73	*
74	* callid = async_get_call(&call);	74	* callid = async_get_call(&call);
75	* handle(callid, call);	75	* handle(callid, call);
76	* ipc_answer_fast(callid, 1,2,3);	76	* ipc_answer_fast(callid, 1,2,3);
77	*	77	*
78	* callid = async_get_call(&call);	78	* callid = async_get_call(&call);
79	* ....	79	* ....
80	* }	80	* }
81	*	81	*
82	* TODO: Detaching/joining dead psthreads?	82	* TODO: Detaching/joining dead psthreads?
83	*/	83	*/
84	#include <futex.h>	84	#include <futex.h>
85	#include <async.h>	85	#include <async.h>
86	#include <psthread.h>	86	#include <psthread.h>
87	#include <stdio.h>	87	#include <stdio.h>
88	#include <libadt/hash_table.h>	88	#include <libadt/hash_table.h>
89	#include <libadt/list.h>	89	#include <libadt/list.h>
90	#include <ipc/ipc.h>	90	#include <ipc/ipc.h>
91	#include <assert.h>	91	#include <assert.h>
92	#include <errno.h>	92	#include <errno.h>
93	#include <time.h>	93	#include <time.h>
94	#include <arch/barrier.h>	94	#include <arch/barrier.h>
95		95
96	atomic_t async_futex = FUTEX_INITIALIZER;	96	atomic_t async_futex = FUTEX_INITIALIZER;
97	static hash_table_t conn_hash_table;	97	static hash_table_t conn_hash_table;
98	static LIST_INITIALIZE(timeout_list);	98	static LIST_INITIALIZE(timeout_list);
99		99
100	typedef struct {	100	typedef struct {
101	struct timeval expires; /*< Expiration time for waiting thread /	101	struct timeval expires; /*< Expiration time for waiting thread /
102	int inlist; /*< If true, this struct is in timeout list /	102	int inlist; /*< If true, this struct is in timeout list /
103	link_t link;	103	link_t link;
104		104
105	pstid_t ptid; /*< Thread waiting for this message /	105	pstid_t ptid; /*< Thread waiting for this message /
106	int active; /*< If this thread is currently active /	106	int active; /*< If this thread is currently active /
107	int timedout; /*< If true, we timed out /	107	int timedout; /*< If true, we timed out /
108	} awaiter_t;	108	} awaiter_t;
109		109
110	typedef struct {	110	typedef struct {
111	awaiter_t wdata;	111	awaiter_t wdata;
112		112
113	int done; /*< If reply was received /	113	int done; /*< If reply was received /
114	ipc_call_t dataptr; /*< Pointer where the answer data	114	ipc_call_t dataptr; /*< Pointer where the answer data
115	* is stored */	115	* is stored */
116	ipcarg_t retval;	116	ipcarg_t retval;
117	} amsg_t;	117	} amsg_t;
118		118
119	typedef struct {	119	typedef struct {
120	link_t link;	120	link_t link;
121	ipc_callid_t callid;	121	ipc_callid_t callid;
122	ipc_call_t call;	122	ipc_call_t call;
123	} msg_t;	123	} msg_t;
124		124
125	typedef struct {	125	typedef struct {
126	awaiter_t wdata;	126	awaiter_t wdata;
127		127
128	link_t link; /*< Hash table link /	128	link_t link; /*< Hash table link /
129	ipcarg_t in_phone_hash; /*< Incoming phone hash. /	129	ipcarg_t in_phone_hash; /*< Incoming phone hash. /
130	link_t msg_queue; /*< Messages that should be delivered to this thread /	130	link_t msg_queue; /*< Messages that should be delivered to this thread /
131	/* Structures for connection opening packet */	131	/* Structures for connection opening packet */
132	ipc_callid_t callid;	132	ipc_callid_t callid;
133	ipc_call_t call;	133	ipc_call_t call;
134	void (cthread)(ipc_callid_t,ipc_call_t );	134	void (cthread)(ipc_callid_t,ipc_call_t );
135	} connection_t;	135	} connection_t;
136		136
137	/** Identifier of incoming connection handled by current thread */	137	/** Identifier of incoming connection handled by current thread */
138	__thread connection_t *PS_connection;	138	__thread connection_t *PS_connection;
139	/** If true, it is forbidden to use async_req functions and	139	/** If true, it is forbidden to use async_req functions and
140	* all preemption is disabled */	140	* all preemption is disabled */
141	__thread int in_interrupt_handler;	141	__thread int in_interrupt_handler;
142		142
143	static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);	143	static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);
144	static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call);	144	static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call);
145	static async_client_conn_t client_connection = default_client_connection;	145	static async_client_conn_t client_connection = default_client_connection;
146	static async_client_conn_t interrupt_received = default_interrupt_received;	146	static async_client_conn_t interrupt_received = default_interrupt_received;
147		147
148	/** Add microseconds to give timeval */	148	/** Add microseconds to give timeval */
149	static void tv_add(struct timeval *tv, suseconds_t usecs)	149	static void tv_add(struct timeval *tv, suseconds_t usecs)
150	{	150	{
151	tv->tv_sec += usecs / 1000000;	151	tv->tv_sec += usecs / 1000000;
152	tv->tv_usec += usecs % 1000000;	152	tv->tv_usec += usecs % 1000000;
153	if (tv->tv_usec > 1000000) {	153	if (tv->tv_usec > 1000000) {
154	tv->tv_sec++;	154	tv->tv_sec++;
155	tv->tv_usec -= 1000000;	155	tv->tv_usec -= 1000000;
156	}	156	}
157	}	157	}
158		158
159	/** Subtract 2 timevals, return microseconds difference */	159	/** Subtract 2 timevals, return microseconds difference */
160	static suseconds_t tv_sub(struct timeval tv1, struct timeval tv2)	160	static suseconds_t tv_sub(struct timeval tv1, struct timeval tv2)
161	{	161	{
162	suseconds_t result;	162	suseconds_t result;
163		163
164	result = tv1->tv_usec - tv2->tv_usec;	164	result = tv1->tv_usec - tv2->tv_usec;
165	result += (tv1->tv_sec - tv2->tv_sec) * 1000000;	165	result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
166		166
167	return result;	167	return result;
168	}	168	}
169		169
170	/** Compare timeval	170	/** Compare timeval
171	*	171	*
172	* @return 1 if tv1 > tv2, otherwise 0	172	* @return 1 if tv1 > tv2, otherwise 0
173	*/	173	*/
174	static int tv_gt(struct timeval tv1, struct timeval tv2)	174	static int tv_gt(struct timeval tv1, struct timeval tv2)
175	{	175	{
176	if (tv1->tv_sec > tv2->tv_sec)	176	if (tv1->tv_sec > tv2->tv_sec)
177	return 1;	177	return 1;
178	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)	178	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
179	return 1;	179	return 1;
180	return 0;	180	return 0;
181	}	181	}
182	static int tv_gteq(struct timeval tv1, struct timeval tv2)	182	static int tv_gteq(struct timeval tv1, struct timeval tv2)
183	{	183	{
184	if (tv1->tv_sec > tv2->tv_sec)	184	if (tv1->tv_sec > tv2->tv_sec)
185	return 1;	185	return 1;
186	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)	186	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
187	return 1;	187	return 1;
188	return 0;	188	return 0;
189	}	189	}
190		190
191	/* Hash table functions */	191	/* Hash table functions */
192	#define CONN_HASH_TABLE_CHAINS 32	192	#define CONN_HASH_TABLE_CHAINS 32
193		193
194	static hash_index_t conn_hash(unsigned long *key)	194	static hash_index_t conn_hash(unsigned long *key)
195	{	195	{
196	assert(key);	196	assert(key);
197	return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;	197	return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
198	}	198	}
199		199
200	static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)	200	static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
201	{	201	{
202	connection_t *hs;	202	connection_t *hs;
203		203
204	hs = hash_table_get_instance(item, connection_t, link);	204	hs = hash_table_get_instance(item, connection_t, link);
205		205
206	return key[0] == hs->in_phone_hash;	206	return key[0] == hs->in_phone_hash;
207	}	207	}
208		208
209	static void conn_remove(link_t *item)	209	static void conn_remove(link_t *item)
210	{	210	{
211	free(hash_table_get_instance(item, connection_t, link));	211	free(hash_table_get_instance(item, connection_t, link));
212	}	212	}
213		213
214		214
215	/** Operations for NS hash table. */	215	/** Operations for NS hash table. */
216	static hash_table_operations_t conn_hash_table_ops = {	216	static hash_table_operations_t conn_hash_table_ops = {
217	.hash = conn_hash,	217	.hash = conn_hash,
218	.compare = conn_compare,	218	.compare = conn_compare,
219	.remove_callback = conn_remove	219	.remove_callback = conn_remove
220	};	220	};
221		221
222	/** Insert sort timeout msg into timeouts list	222	/** Insert sort timeout msg into timeouts list
223	*	223	*
224	*/	224	*/
225	static void insert_timeout(awaiter_t *wd)	225	static void insert_timeout(awaiter_t *wd)
226	{	226	{
227	link_t *tmp;	227	link_t *tmp;
228	awaiter_t *cur;	228	awaiter_t *cur;
229		229
230	wd->timedout = 0;	230	wd->timedout = 0;
231	wd->inlist = 1;	231	wd->inlist = 1;
232		232
233	tmp = timeout_list.next;	233	tmp = timeout_list.next;
234	while (tmp != &timeout_list) {	234	while (tmp != &timeout_list) {
235	cur = list_get_instance(tmp, awaiter_t, link);	235	cur = list_get_instance(tmp, awaiter_t, link);
236	if (tv_gteq(&cur->expires, &wd->expires))	236	if (tv_gteq(&cur->expires, &wd->expires))
237	break;	237	break;
238	tmp = tmp->next;	238	tmp = tmp->next;
239	}	239	}
240	list_append(&wd->link, tmp);	240	list_append(&wd->link, tmp);
241	}	241	}
242		242
243	/*************************************************/	243	/*************************************************/
244		244
245	/** Try to route a call to an appropriate connection thread	245	/** Try to route a call to an appropriate connection thread
246	*	246	*
247	*/	247	*/
248	static int route_call(ipc_callid_t callid, ipc_call_t *call)	248	static int route_call(ipc_callid_t callid, ipc_call_t *call)
249	{	249	{
250	connection_t *conn;	250	connection_t *conn;
251	msg_t *msg;	251	msg_t *msg;
252	link_t *hlp;	252	link_t *hlp;
253	unsigned long key;	253	unsigned long key;
254		254
255	futex_down(&async_futex);	255	futex_down(&async_futex);
256		256
257	key = call->in_phone_hash;	257	key = call->in_phone_hash;
258	hlp = hash_table_find(&conn_hash_table, &key);	258	hlp = hash_table_find(&conn_hash_table, &key);
259	if (!hlp) {	259	if (!hlp) {
260	futex_up(&async_futex);	260	futex_up(&async_futex);
261	return 0;	261	return 0;
262	}	262	}
263	conn = hash_table_get_instance(hlp, connection_t, link);	263	conn = hash_table_get_instance(hlp, connection_t, link);
264		264
265	msg = malloc(sizeof(*msg));	265	msg = malloc(sizeof(*msg));
266	msg->callid = callid;	266	msg->callid = callid;
267	msg->call = *call;	267	msg->call = *call;
268	list_append(&msg->link, &conn->msg_queue);	268	list_append(&msg->link, &conn->msg_queue);
269		269
270	/* If the call is waiting for event, run it */	270	/* If the call is waiting for event, run it */
271	if (!conn->wdata.active) {	271	if (!conn->wdata.active) {
272	/* If in timeout list, remove it */	272	/* If in timeout list, remove it */
273	if (conn->wdata.inlist) {	273	if (conn->wdata.inlist) {
274	conn->wdata.inlist = 0;	274	conn->wdata.inlist = 0;
275	list_remove(&conn->wdata.link);	275	list_remove(&conn->wdata.link);
276	}	276	}
277	conn->wdata.active = 1;	277	conn->wdata.active = 1;
278	psthread_add_ready(conn->wdata.ptid);	278	psthread_add_ready(conn->wdata.ptid);
279	}	279	}
280		280
281	futex_up(&async_futex);	281	futex_up(&async_futex);
282		282
283	return 1;	283	return 1;
284	}	284	}
285		285
286	/** Return new incoming message for current(thread-local) connection */	286	/** Return new incoming message for current(thread-local) connection */
287	ipc_callid_t async_get_call_timeout(ipc_call_t *call, suseconds_t usecs)	287	ipc_callid_t async_get_call_timeout(ipc_call_t *call, suseconds_t usecs)
288	{	288	{
289	msg_t *msg;	289	msg_t *msg;
290	ipc_callid_t callid;	290	ipc_callid_t callid;
291	connection_t *conn;	291	connection_t *conn;
292		292
293	assert(PS_connection);	293	assert(PS_connection);
294	/* GCC 4.1.0 coughs on PS_connection-> dereference,	294	/* GCC 4.1.0 coughs on PS_connection-> dereference,
295	* GCC 4.1.1 happilly puts the rdhwr instruction in delay slot.	295	* GCC 4.1.1 happilly puts the rdhwr instruction in delay slot.
296	* I would never expect to find so many errors in	296	* I would never expect to find so many errors in
297	* compiler ($&$(&$	297	* compiler ($&$(&$
298	*/	298	*/
299	conn = PS_connection;	299	conn = PS_connection;
300		300
301	futex_down(&async_futex);	301	futex_down(&async_futex);
302		302
303	if (usecs) {	303	if (usecs) {
304	gettimeofday(&conn->wdata.expires, NULL);	304	gettimeofday(&conn->wdata.expires, NULL);
305	tv_add(&conn->wdata.expires, usecs);	305	tv_add(&conn->wdata.expires, usecs);
306	} else {	306	} else {
307	conn->wdata.inlist = 0;	307	conn->wdata.inlist = 0;
308	}	308	}
309	/* If nothing in queue, wait until something appears */	309	/* If nothing in queue, wait until something appears */
310	while (list_empty(&conn->msg_queue)) {	310	while (list_empty(&conn->msg_queue)) {
311	if (usecs)	311	if (usecs)
312	insert_timeout(&conn->wdata);	312	insert_timeout(&conn->wdata);
313		313
314	conn->wdata.active = 0;	314	conn->wdata.active = 0;
315	psthread_schedule_next_adv(PS_TO_MANAGER);	315	psthread_schedule_next_adv(PS_TO_MANAGER);
316	/* Futex is up after getting back from async_manager	316	/* Futex is up after getting back from async_manager
317	* get it again */	317	* get it again */
318	futex_down(&async_futex);	318	futex_down(&async_futex);
319	if (usecs && conn->wdata.timedout && \	319	if (usecs && conn->wdata.timedout && \
320	list_empty(&conn->msg_queue)) {	320	list_empty(&conn->msg_queue)) {
321	/* If we timed out-> exit */	321	/* If we timed out-> exit */
322	futex_up(&async_futex);	322	futex_up(&async_futex);
323	return 0;	323	return 0;
324	}	324	}
325	}	325	}
326		326
327	msg = list_get_instance(conn->msg_queue.next, msg_t, link);	327	msg = list_get_instance(conn->msg_queue.next, msg_t, link);
328	list_remove(&msg->link);	328	list_remove(&msg->link);
329	callid = msg->callid;	329	callid = msg->callid;
330	*call = msg->call;	330	*call = msg->call;
331	free(msg);	331	free(msg);
332		332
333	futex_up(&async_futex);	333	futex_up(&async_futex);
334	return callid;	334	return callid;
335	}	335	}
336		336
337	/** Thread function that gets created on new connection	337	/** Thread function that gets created on new connection
338	*	338	*
339	* This function is defined as a weak symbol - to be redefined in	339	* This function is defined as a weak symbol - to be redefined in
340	* user code.	340	* user code.
341	*/	341	*/
342	static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)	342	static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
343	{	343	{
344	ipc_answer_fast(callid, ENOENT, 0, 0);	344	ipc_answer_fast(callid, ENOENT, 0, 0);
345	}	345	}
346	static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call)	346	static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call)
347	{	347	{
348	}	348	}
349		349
350	/** Wrapper for client connection thread	350	/** Wrapper for client connection thread
351	*	351	*
352	* When new connection arrives, thread with this function is created.	352	* When new connection arrives, thread with this function is created.
353	* It calls client_connection and does final cleanup.	353	* It calls client_connection and does final cleanup.
354	*	354	*
355	* @parameter arg Connection structure pointer	355	* @parameter arg Connection structure pointer
356	*/	356	*/
357	static int connection_thread(void *arg)	357	static int connection_thread(void *arg)
358	{	358	{
359	unsigned long key;	359	unsigned long key;
360	msg_t *msg;	360	msg_t *msg;
361		361
362	/* Setup thread local connection pointer */	362	/* Setup thread local connection pointer */
363	PS_connection = (connection_t *)arg;	363	PS_connection = (connection_t *)arg;
364	PS_connection->cthread(PS_connection->callid, &PS_connection->call);	364	PS_connection->cthread(PS_connection->callid, &PS_connection->call);
365	/* Remove myself from connection hash table */	365	/* Remove myself from connection hash table */
366	futex_down(&async_futex);	366	futex_down(&async_futex);
367	key = PS_connection->in_phone_hash;	367	key = PS_connection->in_phone_hash;
368	hash_table_remove(&conn_hash_table, &key, 1);	368	hash_table_remove(&conn_hash_table, &key, 1);
369	futex_up(&async_futex);	369	futex_up(&async_futex);
370	/* Answer all remaining messages with ehangup */	370	/* Answer all remaining messages with ehangup */
371	while (!list_empty(&PS_connection->msg_queue)) {	371	while (!list_empty(&PS_connection->msg_queue)) {
372	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);	372	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
373	list_remove(&msg->link);	373	list_remove(&msg->link);
374	ipc_answer_fast(msg->callid, EHANGUP, 0, 0);	374	ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
375	free(msg);	375	free(msg);
376	}	376	}
377	}	377	}
378		378
379	/** Create new thread for a new connection	379	/** Create new thread for a new connection
380	*	380	*
381	* Creates new thread for connection, fills in connection	381	* Creates new thread for connection, fills in connection
382	* structures and inserts it into the hash table, so that	382	* structures and inserts it into the hash table, so that
383	* later we can easily do routing of messages to particular	383	* later we can easily do routing of messages to particular
384	* threads.	384	* threads.
385	*	385	*
386	* @param in_phone_hash Identification of the incoming connection	386	* @param in_phone_hash Identification of the incoming connection
387	* @param callid Callid of the IPC_M_CONNECT_ME_TO packet	387	* @param callid Callid of the IPC_M_CONNECT_ME_TO packet
388	* @param call Call data of the opening packet	388	* @param call Call data of the opening packet
389	* @param cthread Thread function that should be called upon	389	* @param cthread Thread function that should be called upon
390	* opening the connection	390	* opening the connection
391	* @return New thread id	391	* @return New thread id
392	*/	392	*/
393	pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,	393	pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,
394	ipc_call_t *call,	394	ipc_call_t *call,
395	void (cthread)(ipc_callid_t,ipc_call_t ))	395	void (cthread)(ipc_callid_t,ipc_call_t ))
396	{	396	{
397	pstid_t ptid;	397	pstid_t ptid;
398	connection_t *conn;	398	connection_t *conn;
399	unsigned long key;	399	unsigned long key;
400		400
401	conn = malloc(sizeof(*conn));	401	conn = malloc(sizeof(*conn));
402	if (!conn) {	402	if (!conn) {
403	ipc_answer_fast(callid, ENOMEM, 0, 0);	403	ipc_answer_fast(callid, ENOMEM, 0, 0);
404	return NULL;	404	return NULL;
405	}	405	}
406	conn->in_phone_hash = in_phone_hash;	406	conn->in_phone_hash = in_phone_hash;
407	list_initialize(&conn->msg_queue);	407	list_initialize(&conn->msg_queue);
408	conn->callid = callid;	408	conn->callid = callid;
409	if (call)	409	if (call)
410	conn->call = *call;	410	conn->call = *call;
411	conn->wdata.active = 1; /* We will activate it asap */	411	conn->wdata.active = 1; /* We will activate it asap */
412	conn->cthread = cthread;	412	conn->cthread = cthread;
413		413
414	conn->wdata.ptid = psthread_create(connection_thread, conn);	414	conn->wdata.ptid = psthread_create(connection_thread, conn);
415	if (!conn->wdata.ptid) {	415	if (!conn->wdata.ptid) {
416	free(conn);	416	free(conn);
417	ipc_answer_fast(callid, ENOMEM, 0, 0);	417	ipc_answer_fast(callid, ENOMEM, 0, 0);
418	return NULL;	418	return NULL;
419	}	419	}
420	/* Add connection to hash table */	420	/* Add connection to hash table */
421	key = conn->in_phone_hash;	421	key = conn->in_phone_hash;
422	futex_down(&async_futex);	422	futex_down(&async_futex);
423	hash_table_insert(&conn_hash_table, &key, &conn->link);	423	hash_table_insert(&conn_hash_table, &key, &conn->link);
424	futex_up(&async_futex);	424	futex_up(&async_futex);
425		425
426	psthread_add_ready(conn->wdata.ptid);	426	psthread_add_ready(conn->wdata.ptid);
427		427
428	return conn->wdata.ptid;	428	return conn->wdata.ptid;
429	}	429	}
430		430
431	/** Handle call that was received */	431	/** Handle call that was received */
432	static void handle_call(ipc_callid_t callid, ipc_call_t *call)	432	static void handle_call(ipc_callid_t callid, ipc_call_t *call)
433	{	433	{
434	/* Unrouted call - do some default behaviour */	434	/* Unrouted call - do some default behaviour */
435	switch (IPC_GET_METHOD(*call)) {	435	switch (IPC_GET_METHOD(*call)) {
436	case IPC_M_INTERRUPT:	436	case IPC_M_INTERRUPT:
437	in_interrupt_handler = 1;	437	in_interrupt_handler = 1;
438	(*interrupt_received)(callid,call);	438	(*interrupt_received)(callid,call);
439	in_interrupt_handler = 0;	439	in_interrupt_handler = 0;
440	return;	440	return;
441	case IPC_M_CONNECT_ME_TO:	441	case IPC_M_CONNECT_ME_TO:
442	/* Open new connection with thread etc. */	442	/* Open new connection with thread etc. */
443	async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);	443	async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
444	return;	444	return;
445	}	445	}
446		446
447	/* Try to route call through connection tables */	447	/* Try to route call through connection tables */
448	if (route_call(callid, call))	448	if (route_call(callid, call))
449	return;	449	return;
450		450
451	/* Unknown call from unknown phone - hang it up */	451	/* Unknown call from unknown phone - hang it up */
452	ipc_answer_fast(callid, EHANGUP, 0, 0);	452	ipc_answer_fast(callid, EHANGUP, 0, 0);
453	}	453	}
454		454
455	/** Fire all timeouts that expired	455	/** Fire all timeouts that expired
456	*	456	*
457	*/	457	*/
458	static void handle_expired_timeouts(void)	458	static void handle_expired_timeouts(void)
459	{	459	{
460	struct timeval tv;	460	struct timeval tv;
461	awaiter_t *waiter;	461	awaiter_t *waiter;
462	link_t *cur;	462	link_t *cur;
463		463
464	gettimeofday(&tv,NULL);	464	gettimeofday(&tv,NULL);
465	futex_down(&async_futex);	465	futex_down(&async_futex);
466		466
467	cur = timeout_list.next;	467	cur = timeout_list.next;
468	while (cur != &timeout_list) {	468	while (cur != &timeout_list) {
469	waiter = list_get_instance(cur,awaiter_t,link);	469	waiter = list_get_instance(cur,awaiter_t,link);
470	if (tv_gt(&waiter->expires, &tv))	470	if (tv_gt(&waiter->expires, &tv))
471	break;	471	break;
472	cur = cur->next;	472	cur = cur->next;
473	list_remove(&waiter->link);	473	list_remove(&waiter->link);
474	waiter->inlist = 0;	474	waiter->inlist = 0;
475	waiter->timedout = 1;	475	waiter->timedout = 1;
476	/* Redundant condition? The thread should not	476	/* Redundant condition? The thread should not
477	* be active when it gets here.	477	* be active when it gets here.
478	*/	478	*/
479	if (!waiter->active) {	479	if (!waiter->active) {
480	waiter->active = 1;	480	waiter->active = 1;
481	psthread_add_ready(waiter->ptid);	481	psthread_add_ready(waiter->ptid);
482	}	482	}
483	}	483	}
484		484
485	futex_up(&async_futex);	485	futex_up(&async_futex);
486	}	486	}
487		487
488	/** Endless loop dispatching incoming calls and answers */	488	/** Endless loop dispatching incoming calls and answers */
489	static int async_manager_worker(void)	489	static int async_manager_worker(void)
490	{	490	{
491	ipc_call_t call;	491	ipc_call_t call;
492	ipc_callid_t callid;	492	ipc_callid_t callid;
493	int timeout;	493	int timeout;
494	awaiter_t *waiter;	494	awaiter_t *waiter;
495	struct timeval tv;	495	struct timeval tv;
496		496
497	while (1) {	497	while (1) {
498	if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {	498	if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
499	futex_up(&async_futex); /* async_futex is always held	499	futex_up(&async_futex); /* async_futex is always held
500	* when entering manager thread	500	* when entering manager thread

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/async.c @ 1648 – Rev 1610 → 1614