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 {
    pstid_t ptid;                /**< Thread waiting for this message */
    int active;                  /**< If this thread is currently active */
    int done;                    /**< If reply was received */
    ipc_call_t *dataptr;         /**< Pointer where the answer data
                      *   should be stored */
    struct timeval expires;      /**< Expiration time for waiting thread */
    int has_timeout;             /**< If true, this struct is in timeout list */
    link_t link;
 
    ipcarg_t retval;
} amsg_t;
 
typedef struct {
    link_t link;
    ipc_callid_t callid;
    ipc_call_t call;
} msg_t;
 
typedef struct {
    link_t link;
    ipcarg_t in_phone_hash;     /**< Incoming phone hash. */
    link_t msg_queue;              /**< Messages that should be delivered to this thread */
    pstid_t ptid;                /**< Thread associated with this connection */
    int active;                     /**< If this thread is currently active */
    /* Structures for connection opening packet */
    ipc_callid_t callid;
    ipc_call_t call;
    void (*cthread)(ipc_callid_t,ipc_call_t *);
} connection_t;
 
 
__thread connection_t *PS_connection;
 
static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);
static async_client_conn_t client_connection = default_client_connection;
 
/** 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
};
 
/*************************************************/
 
/** 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 (!conn->active) {
        conn->active = 1;
        psthread_add_ready(conn->ptid);
    }
 
    futex_up(&async_futex);
 
    return 1;
}
 
/** Return new incoming message for current(thread-local) connection */
ipc_callid_t async_get_call(ipc_call_t *call)
{
    msg_t *msg;
    ipc_callid_t callid;
   
    assert(PS_connection);
 
    futex_down(&async_futex);
 
    /* If nothing in queue, wait until something appears */
    if (list_empty(&PS_connection->msg_queue)) {
        PS_connection->active = 0;
        psthread_schedule_next_adv(PS_TO_MANAGER);
    }
   
    msg = list_get_instance(PS_connection->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);
}
 
/** Function that gets called on interrupt receival
 *
 * This function is defined as a weak symbol - to be redefined in
 * user code.
 */
void interrupt_received(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->ptid = psthread_create(connection_thread, conn);
    conn->callid = callid;
    if (call)
        conn->call = *call;
    conn->active = 1; /* We will activate it asap */
    conn->cthread = cthread;
    list_initialize(&conn->link);
    if (!conn->ptid) {
        free(conn);
        ipc_answer_fast(callid, ENOMEM, 0, 0);
        return NULL;
    }
    key = conn->in_phone_hash;
    futex_down(&async_futex);
    /* Add connection to hash table */
    hash_table_insert(&conn_hash_table, &key, &conn->link);
    futex_up(&async_futex);
 
    psthread_add_ready(conn->ptid);
 
    return conn->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:
        interrupt_received(call);
        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;
    amsg_t *amsg;
    link_t *cur;
 
    gettimeofday(&tv,NULL);
    futex_down(&async_futex);
 
    cur = timeout_list.next;
    while (cur != &timeout_list) {
        amsg = list_get_instance(cur,amsg_t,link);
        if (tv_gt(&amsg->expires, &tv))
            break;
        cur = cur->next;
        list_remove(&amsg->link);
        amsg->has_timeout = 0;
        /* Redundant condition? The thread should not
         * be active when it gets here.
         */
        if (!amsg->active) {
            amsg->active = 1;
            psthread_add_ready(amsg->ptid);        
        }
    }
 
    futex_up(&async_futex);
}
 
/** Endless loop dispatching incoming calls and answers */
int async_manager(void)
{
    ipc_call_t call;
    ipc_callid_t callid;
    int timeout;
    amsg_t *amsg;
    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)) {
            amsg = list_get_instance(timeout_list.next,amsg_t,link);
            gettimeofday(&tv,NULL);
            if (tv_gteq(&tv, &amsg->expires)) {
                handle_expired_timeouts();
                continue;
            } else
                timeout = tv_sub(&amsg->expires, &tv);
        } else
            timeout = SYNCH_NO_TIMEOUT;
        futex_up(&async_futex);
 
        callid = ipc_wait_cycle(&call, timeout, SYNCH_BLOCKING);
 
        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();
}
 
/** 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->has_timeout)
        list_remove(&msg->link);
    msg->done = 1;
    if (! msg->active) {
        msg->active = 1;
        psthread_add_ready(msg->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;
 
    msg = malloc(sizeof(*msg));
    msg->active = 1;
    msg->done = 0;
    msg->dataptr = dataptr;
    ipc_call_async_2(phoneid,method,arg1,arg2,msg,reply_received);
 
    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->ptid = psthread_get_id();
    msg->active = 0;
    msg->has_timeout = 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);
}
 
/** Insert sort timeout msg into timeouts list
 *
 * Assume async_futex is held
 */
static void insert_timeout(amsg_t *msg)
{
    link_t *tmp;
    amsg_t *cur;
 
    tmp = timeout_list.next;
    while (tmp != &timeout_list) {
        cur = list_get_instance(tmp, amsg_t, link);
        if (tv_gteq(&cur->expires, &msg->expires))
            break;
        tmp = tmp->next;
    }
    list_append(&msg->link, tmp);
}
 
/** 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;
 
    futex_down(&async_futex);
    if (msg->done) {
        futex_up(&async_futex);
        goto done;
    }
 
    msg->ptid = psthread_get_id();
    msg->active = 0;
    msg->has_timeout = 1;
 
    gettimeofday(&msg->expires, NULL);
    tv_add(&msg->expires, timeout);
    insert_timeout(msg);
 
    /* 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;
   
    msg = malloc(sizeof(*msg));
    if (!msg)
        return;
 
    msg->ptid = psthread_get_id();
    msg->active = 0;
    msg->has_timeout = 1;
 
    gettimeofday(&msg->expires, NULL);
    tv_add(&msg->expires, timeout);
 
    futex_down(&async_futex);
    insert_timeout(msg);
    /* 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;
}
 

Rev 1470	Rev 1490
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	pstid_t ptid; /*< Thread waiting for this message /	101	pstid_t ptid; /*< Thread waiting for this message /
102	int active; /*< If this thread is currently active /	102	int active; /*< If this thread is currently active /
103	int done; /*< If reply was received /	103	int done; /*< If reply was received /
104	ipc_call_t dataptr; /*< Pointer where the answer data	104	ipc_call_t dataptr; /*< Pointer where the answer data
105	* should be stored */	105	* should be stored */
106	struct timeval expires; /*< Expiration time for waiting thread /	106	struct timeval expires; /*< Expiration time for waiting thread /
107	int has_timeout; /*< If true, this struct is in timeout list /	107	int has_timeout; /*< If true, this struct is in timeout list /
108	link_t link;	108	link_t link;
109		109
110	ipcarg_t retval;	110	ipcarg_t retval;
111	} amsg_t;	111	} amsg_t;
112		112
113	typedef struct {	113	typedef struct {
114	link_t link;	114	link_t link;
115	ipc_callid_t callid;	115	ipc_callid_t callid;
116	ipc_call_t call;	116	ipc_call_t call;
117	} msg_t;	117	} msg_t;
118		118
119	typedef struct {	119	typedef struct {
120	link_t link;	120	link_t link;
121	ipcarg_t in_phone_hash; /*< Incoming phone hash. /	121	ipcarg_t in_phone_hash; /*< Incoming phone hash. /
122	link_t msg_queue; /*< Messages that should be delivered to this thread /	122	link_t msg_queue; /*< Messages that should be delivered to this thread /
123	pstid_t ptid; /*< Thread associated with this connection /	123	pstid_t ptid; /*< Thread associated with this connection /
124	int active; /*< If this thread is currently active /	124	int active; /*< If this thread is currently active /
125	/* Structures for connection opening packet */	125	/* Structures for connection opening packet */
126	ipc_callid_t callid;	126	ipc_callid_t callid;
127	ipc_call_t call;	127	ipc_call_t call;
128	void (cthread)(ipc_callid_t,ipc_call_t );	128	void (cthread)(ipc_callid_t,ipc_call_t );
129	} connection_t;	129	} connection_t;
130		130
-		131
131	__thread connection_t *PS_connection;	132	__thread connection_t *PS_connection;
132		133
-		134	static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);
-		135	static async_client_conn_t client_connection = default_client_connection;
-		136
133	/** Add microseconds to give timeval */	137	/** Add microseconds to give timeval */
134	static void tv_add(struct timeval *tv, suseconds_t usecs)	138	static void tv_add(struct timeval *tv, suseconds_t usecs)
135	{	139	{
136	tv->tv_sec += usecs / 1000000;	140	tv->tv_sec += usecs / 1000000;
137	tv->tv_usec += usecs % 1000000;	141	tv->tv_usec += usecs % 1000000;
138	if (tv->tv_usec > 1000000) {	142	if (tv->tv_usec > 1000000) {
139	tv->tv_sec++;	143	tv->tv_sec++;
140	tv->tv_usec -= 1000000;	144	tv->tv_usec -= 1000000;
141	}	145	}
142	}	146	}
143		147
144	/** Subtract 2 timevals, return microseconds difference */	148	/** Subtract 2 timevals, return microseconds difference */
145	static suseconds_t tv_sub(struct timeval tv1, struct timeval tv2)	149	static suseconds_t tv_sub(struct timeval tv1, struct timeval tv2)
146	{	150	{
147	suseconds_t result;	151	suseconds_t result;
148		152
149	result = tv1->tv_usec - tv2->tv_usec;	153	result = tv1->tv_usec - tv2->tv_usec;
150	result += (tv1->tv_sec - tv2->tv_sec) * 1000000;	154	result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
151		155
152	return result;	156	return result;
153	}	157	}
154		158
155	/** Compare timeval	159	/** Compare timeval
156	*	160	*
157	* @return 1 if tv1 > tv2, otherwise 0	161	* @return 1 if tv1 > tv2, otherwise 0
158	*/	162	*/
159	static int tv_gt(struct timeval tv1, struct timeval tv2)	163	static int tv_gt(struct timeval tv1, struct timeval tv2)
160	{	164	{
161	if (tv1->tv_sec > tv2->tv_sec)	165	if (tv1->tv_sec > tv2->tv_sec)
162	return 1;	166	return 1;
163	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)	167	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
164	return 1;	168	return 1;
165	return 0;	169	return 0;
166	}	170	}
167	static int tv_gteq(struct timeval tv1, struct timeval tv2)	171	static int tv_gteq(struct timeval tv1, struct timeval tv2)
168	{	172	{
169	if (tv1->tv_sec > tv2->tv_sec)	173	if (tv1->tv_sec > tv2->tv_sec)
170	return 1;	174	return 1;
171	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)	175	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
172	return 1;	176	return 1;
173	return 0;	177	return 0;
174	}	178	}
175		179
176	/* Hash table functions */	180	/* Hash table functions */
177	#define CONN_HASH_TABLE_CHAINS 32	181	#define CONN_HASH_TABLE_CHAINS 32
178		182
179	static hash_index_t conn_hash(unsigned long *key)	183	static hash_index_t conn_hash(unsigned long *key)
180	{	184	{
181	assert(key);	185	assert(key);
182	return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;	186	return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
183	}	187	}
184		188
185	static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)	189	static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
186	{	190	{
187	connection_t *hs;	191	connection_t *hs;
188		192
189	hs = hash_table_get_instance(item, connection_t, link);	193	hs = hash_table_get_instance(item, connection_t, link);
190		194
191	return key[0] == hs->in_phone_hash;	195	return key[0] == hs->in_phone_hash;
192	}	196	}
193		197
194	static void conn_remove(link_t *item)	198	static void conn_remove(link_t *item)
195	{	199	{
196	free(hash_table_get_instance(item, connection_t, link));	200	free(hash_table_get_instance(item, connection_t, link));
197	}	201	}
198		202
199		203
200	/** Operations for NS hash table. */	204	/** Operations for NS hash table. */
201	static hash_table_operations_t conn_hash_table_ops = {	205	static hash_table_operations_t conn_hash_table_ops = {
202	.hash = conn_hash,	206	.hash = conn_hash,
203	.compare = conn_compare,	207	.compare = conn_compare,
204	.remove_callback = conn_remove	208	.remove_callback = conn_remove
205	};	209	};
206		210
207	/*************************************************/	211	/*************************************************/
208		212
209	/** Try to route a call to an appropriate connection thread	213	/** Try to route a call to an appropriate connection thread
210	*	214	*
211	*/	215	*/
212	static int route_call(ipc_callid_t callid, ipc_call_t *call)	216	static int route_call(ipc_callid_t callid, ipc_call_t *call)
213	{	217	{
214	connection_t *conn;	218	connection_t *conn;
215	msg_t *msg;	219	msg_t *msg;
216	link_t *hlp;	220	link_t *hlp;
217	unsigned long key;	221	unsigned long key;
218		222
219	futex_down(&async_futex);	223	futex_down(&async_futex);
220		224
221	key = call->in_phone_hash;	225	key = call->in_phone_hash;
222	hlp = hash_table_find(&conn_hash_table, &key);	226	hlp = hash_table_find(&conn_hash_table, &key);
223	if (!hlp) {	227	if (!hlp) {
224	futex_up(&async_futex);	228	futex_up(&async_futex);
225	return 0;	229	return 0;
226	}	230	}
227	conn = hash_table_get_instance(hlp, connection_t, link);	231	conn = hash_table_get_instance(hlp, connection_t, link);
228		232
229	msg = malloc(sizeof(*msg));	233	msg = malloc(sizeof(*msg));
230	msg->callid = callid;	234	msg->callid = callid;
231	msg->call = *call;	235	msg->call = *call;
232	list_append(&msg->link, &conn->msg_queue);	236	list_append(&msg->link, &conn->msg_queue);
233		237
234	if (!conn->active) {	238	if (!conn->active) {
235	conn->active = 1;	239	conn->active = 1;
236	psthread_add_ready(conn->ptid);	240	psthread_add_ready(conn->ptid);
237	}	241	}
238		242
239	futex_up(&async_futex);	243	futex_up(&async_futex);
240		244
241	return 1;	245	return 1;
242	}	246	}
243		247
244	/** Return new incoming message for current(thread-local) connection */	248	/** Return new incoming message for current(thread-local) connection */
245	ipc_callid_t async_get_call(ipc_call_t *call)	249	ipc_callid_t async_get_call(ipc_call_t *call)
246	{	250	{
247	msg_t *msg;	251	msg_t *msg;
248	ipc_callid_t callid;	252	ipc_callid_t callid;
249		253
250	assert(PS_connection);	254	assert(PS_connection);
251		255
252	futex_down(&async_futex);	256	futex_down(&async_futex);
253		257
254	/* If nothing in queue, wait until something appears */	258	/* If nothing in queue, wait until something appears */
255	if (list_empty(&PS_connection->msg_queue)) {	259	if (list_empty(&PS_connection->msg_queue)) {
256	PS_connection->active = 0;	260	PS_connection->active = 0;
257	psthread_schedule_next_adv(PS_TO_MANAGER);	261	psthread_schedule_next_adv(PS_TO_MANAGER);
258	}	262	}
259		263
260	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);	264	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
261	list_remove(&msg->link);	265	list_remove(&msg->link);
262	callid = msg->callid;	266	callid = msg->callid;
263	*call = msg->call;	267	*call = msg->call;
264	free(msg);	268	free(msg);
265		269
266	futex_up(&async_futex);	270	futex_up(&async_futex);
267	return callid;	271	return callid;
268	}	272	}
269		273
270	/** Thread function that gets created on new connection	274	/** Thread function that gets created on new connection
271	*	275	*
272	* This function is defined as a weak symbol - to be redefined in	276	* This function is defined as a weak symbol - to be redefined in
273	* user code.	277	* user code.
274	*/	278	*/
275	void client_connection(ipc_callid_t callid, ipc_call_t *call)	279	static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
276	{	280	{
277	ipc_answer_fast(callid, ENOENT, 0, 0);	281	ipc_answer_fast(callid, ENOENT, 0, 0);
278	}	282	}
279		283
280	/** Function that gets called on interrupt receival	284	/** Function that gets called on interrupt receival
281	*	285	*
282	* This function is defined as a weak symbol - to be redefined in	286	* This function is defined as a weak symbol - to be redefined in
283	* user code.	287	* user code.
284	*/	288	*/
285	void interrupt_received(ipc_call_t *call)	289	void interrupt_received(ipc_call_t *call)
286	{	290	{
287	}	291	}
288		292
289		293
290	/** Wrapper for client connection thread	294	/** Wrapper for client connection thread
291	*	295	*
292	* When new connection arrives, thread with this function is created.	296	* When new connection arrives, thread with this function is created.
293	* It calls client_connection and does final cleanup.	297	* It calls client_connection and does final cleanup.
294	*	298	*
295	* @parameter arg Connection structure pointer	299	* @parameter arg Connection structure pointer
296	*/	300	*/
297	static int connection_thread(void *arg)	301	static int connection_thread(void *arg)
298	{	302	{
299	unsigned long key;	303	unsigned long key;
300	msg_t *msg;	304	msg_t *msg;
301		305
302	/* Setup thread local connection pointer */	306	/* Setup thread local connection pointer */
303	PS_connection = (connection_t *)arg;	307	PS_connection = (connection_t *)arg;
304	PS_connection->cthread(PS_connection->callid, &PS_connection->call);	308	PS_connection->cthread(PS_connection->callid, &PS_connection->call);
305		309
306	/* Remove myself from connection hash table */	310	/* Remove myself from connection hash table */
307	futex_down(&async_futex);	311	futex_down(&async_futex);
308	key = PS_connection->in_phone_hash;	312	key = PS_connection->in_phone_hash;
309	hash_table_remove(&conn_hash_table, &key, 1);	313	hash_table_remove(&conn_hash_table, &key, 1);
310	futex_up(&async_futex);	314	futex_up(&async_futex);
311	/* Answer all remaining messages with ehangup */	315	/* Answer all remaining messages with ehangup */
312	while (!list_empty(&PS_connection->msg_queue)) {	316	while (!list_empty(&PS_connection->msg_queue)) {
313	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);	317	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
314	list_remove(&msg->link);	318	list_remove(&msg->link);
315	ipc_answer_fast(msg->callid, EHANGUP, 0, 0);	319	ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
316	free(msg);	320	free(msg);
317	}	321	}
318	}	322	}
319		323
320	/** Create new thread for a new connection	324	/** Create new thread for a new connection
321	*	325	*
322	* Creates new thread for connection, fills in connection	326	* Creates new thread for connection, fills in connection
323	* structures and inserts it into the hash table, so that	327	* structures and inserts it into the hash table, so that
324	* later we can easily do routing of messages to particular	328	* later we can easily do routing of messages to particular
325	* threads.	329	* threads.
326	*	330	*
327	* @param in_phone_hash Identification of the incoming connection	331	* @param in_phone_hash Identification of the incoming connection
328	* @param callid Callid of the IPC_M_CONNECT_ME_TO packet	332	* @param callid Callid of the IPC_M_CONNECT_ME_TO packet
329	* @param call Call data of the opening packet	333	* @param call Call data of the opening packet
330	* @param cthread Thread function that should be called upon	334	* @param cthread Thread function that should be called upon
331	* opening the connection	335	* opening the connection
332	* @return New thread id	336	* @return New thread id
333	*/	337	*/
334	pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,	338	pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,
335	ipc_call_t *call,	339	ipc_call_t *call,
336	void (cthread)(ipc_callid_t,ipc_call_t ))	340	void (cthread)(ipc_callid_t,ipc_call_t ))
337	{	341	{
338	pstid_t ptid;	342	pstid_t ptid;
339	connection_t *conn;	343	connection_t *conn;
340	unsigned long key;	344	unsigned long key;
341		345
342	conn = malloc(sizeof(*conn));	346	conn = malloc(sizeof(*conn));
343	if (!conn) {	347	if (!conn) {
344	ipc_answer_fast(callid, ENOMEM, 0, 0);	348	ipc_answer_fast(callid, ENOMEM, 0, 0);
345	return NULL;	349	return NULL;
346	}	350	}
347	conn->in_phone_hash = in_phone_hash;	351	conn->in_phone_hash = in_phone_hash;
348	list_initialize(&conn->msg_queue);	352	list_initialize(&conn->msg_queue);
349	conn->ptid = psthread_create(connection_thread, conn);	353	conn->ptid = psthread_create(connection_thread, conn);
350	conn->callid = callid;	354	conn->callid = callid;
351	if (call)	355	if (call)
352	conn->call = *call;	356	conn->call = *call;
353	conn->active = 1; /* We will activate it asap */	357	conn->active = 1; /* We will activate it asap */
354	conn->cthread = cthread;	358	conn->cthread = cthread;
355	list_initialize(&conn->link);	359	list_initialize(&conn->link);
356	if (!conn->ptid) {	360	if (!conn->ptid) {
357	free(conn);	361	free(conn);
358	ipc_answer_fast(callid, ENOMEM, 0, 0);	362	ipc_answer_fast(callid, ENOMEM, 0, 0);
359	return NULL;	363	return NULL;
360	}	364	}
361	key = conn->in_phone_hash;	365	key = conn->in_phone_hash;
362	futex_down(&async_futex);	366	futex_down(&async_futex);
363	/* Add connection to hash table */	367	/* Add connection to hash table */
364	hash_table_insert(&conn_hash_table, &key, &conn->link);	368	hash_table_insert(&conn_hash_table, &key, &conn->link);
365	futex_up(&async_futex);	369	futex_up(&async_futex);
366		370
367	psthread_add_ready(conn->ptid);	371	psthread_add_ready(conn->ptid);
368		372
369	return conn->ptid;	373	return conn->ptid;
370	}	374	}
371		375
372	/** Handle call that was received */	376	/** Handle call that was received */
373	static void handle_call(ipc_callid_t callid, ipc_call_t *call)	377	static void handle_call(ipc_callid_t callid, ipc_call_t *call)
374	{	378	{
375	/* Unrouted call - do some default behaviour */	379	/* Unrouted call - do some default behaviour */
376	switch (IPC_GET_METHOD(*call)) {	380	switch (IPC_GET_METHOD(*call)) {
377	case IPC_M_INTERRUPT:	381	case IPC_M_INTERRUPT:
378	interrupt_received(call);	382	interrupt_received(call);
379	return;	383	return;
380	case IPC_M_CONNECT_ME_TO:	384	case IPC_M_CONNECT_ME_TO:
381	/* Open new connection with thread etc. */	385	/* Open new connection with thread etc. */
382	async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);	386	async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
383	return;	387	return;
384	}	388	}
385		389
386	/* Try to route call through connection tables */	390	/* Try to route call through connection tables */
387	if (route_call(callid, call))	391	if (route_call(callid, call))
388	return;	392	return;
389		393
390	/* Unknown call from unknown phone - hang it up */	394	/* Unknown call from unknown phone - hang it up */
391	ipc_answer_fast(callid, EHANGUP, 0, 0);	395	ipc_answer_fast(callid, EHANGUP, 0, 0);
392	}	396	}
393		397
394	/** Fire all timeouts that expired */	398	/** Fire all timeouts that expired */
395	static void handle_expired_timeouts(void)	399	static void handle_expired_timeouts(void)
396	{	400	{
397	struct timeval tv;	401	struct timeval tv;
398	amsg_t *amsg;	402	amsg_t *amsg;
399	link_t *cur;	403	link_t *cur;
400		404
401	gettimeofday(&tv,NULL);	405	gettimeofday(&tv,NULL);
402	futex_down(&async_futex);	406	futex_down(&async_futex);
403		407
404	cur = timeout_list.next;	408	cur = timeout_list.next;
405	while (cur != &timeout_list) {	409	while (cur != &timeout_list) {
406	amsg = list_get_instance(cur,amsg_t,link);	410	amsg = list_get_instance(cur,amsg_t,link);
407	if (tv_gt(&amsg->expires, &tv))	411	if (tv_gt(&amsg->expires, &tv))
408	break;	412	break;
409	cur = cur->next;	413	cur = cur->next;
410	list_remove(&amsg->link);	414	list_remove(&amsg->link);
411	amsg->has_timeout = 0;	415	amsg->has_timeout = 0;
412	/* Redundant condition? The thread should not	416	/* Redundant condition? The thread should not
413	* be active when it gets here.	417	* be active when it gets here.
414	*/	418	*/
415	if (!amsg->active) {	419	if (!amsg->active) {
416	amsg->active = 1;	420	amsg->active = 1;
417	psthread_add_ready(amsg->ptid);	421	psthread_add_ready(amsg->ptid);
418	}	422	}
419	}	423	}
420		424
421	futex_up(&async_futex);	425	futex_up(&async_futex);
422	}	426	}
423		427
424	/** Endless loop dispatching incoming calls and answers */	428	/** Endless loop dispatching incoming calls and answers */
425	int async_manager(void)	429	int async_manager(void)
426	{	430	{
427	ipc_call_t call;	431	ipc_call_t call;
428	ipc_callid_t callid;	432	ipc_callid_t callid;
429	int timeout;	433	int timeout;
430	amsg_t *amsg;	434	amsg_t *amsg;
431	struct timeval tv;	435	struct timeval tv;
432		436
433	while (1) {	437	while (1) {
434	if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {	438	if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
435	futex_up(&async_futex); /* async_futex is always held	439	futex_up(&async_futex); /* async_futex is always held
436	* when entering manager thread	440	* when entering manager thread
437	*/	441	*/
438	continue;	442	continue;
439	}	443	}
440	futex_down(&async_futex);	444	futex_down(&async_futex);
441	if (!list_empty(&timeout_list)) {	445	if (!list_empty(&timeout_list)) {
442	amsg = list_get_instance(timeout_list.next,amsg_t,link);	446	amsg = list_get_instance(timeout_list.next,amsg_t,link);
443	gettimeofday(&tv,NULL);	447	gettimeofday(&tv,NULL);
444	if (tv_gteq(&tv, &amsg->expires)) {	448	if (tv_gteq(&tv, &amsg->expires)) {
445	handle_expired_timeouts();	449	handle_expired_timeouts();
446	continue;	450	continue;
447	} else	451	} else
448	timeout = tv_sub(&amsg->expires, &tv);	452	timeout = tv_sub(&amsg->expires, &tv);
449	} else	453	} else
450	timeout = SYNCH_NO_TIMEOUT;	454	timeout = SYNCH_NO_TIMEOUT;
451	futex_up(&async_futex);	455	futex_up(&async_futex);
452		456
453	callid = ipc_wait_cycle(&call, timeout, SYNCH_BLOCKING);	457	callid = ipc_wait_cycle(&call, timeout, SYNCH_BLOCKING);
454		458
455	if (!callid) {	459	if (!callid) {
456	handle_expired_timeouts();	460	handle_expired_timeouts();
457	continue;	461	continue;
458	}	462	}
459		463
460	if (callid & IPC_CALLID_ANSWERED)	464	if (callid & IPC_CALLID_ANSWERED)
461	continue;	465	continue;
462		466
463	handle_call(callid, &call);	467	handle_call(callid, &call);
464	}	468	}
465	}	469	}
466		470
467	/** Function to start async_manager as a standalone thread	471	/** Function to start async_manager as a standalone thread
468	*	472	*
469	* When more kernel threads are used, one async manager should	473	* When more kernel threads are used, one async manager should
470	* exist per thread. The particular implementation may change,	474	* exist per thread. The particular implementation may change,
471	* currently one async_manager is started automatically per kernel	475	* currently one async_manager is started automatically per kernel
472	* thread except main thread.	476	* thread except main thread.
473	*/	477	*/
474	static int async_manager_thread(void *arg)	478	static int async_manager_thread(void *arg)
475	{	479	{
476	futex_up(&async_futex); /* async_futex is always locked when entering	480	futex_up(&async_futex); /* async_futex is always locked when entering
477	* manager */	481	* manager */
478	async_manager();	482	async_manager();
479	}	483	}
480		484
481	/** Add one manager to manager list */	485	/** Add one manager to manager list */
482	void async_create_manager(void)	486	void async_create_manager(void)
483	{	487	{
484	pstid_t ptid;	488	pstid_t ptid;
485		489
486	ptid = psthread_create(async_manager_thread, NULL);	490	ptid = psthread_create(async_manager_thread, NULL);
487	psthread_add_manager(ptid);	491	psthread_add_manager(ptid);
488	}	492	}
489		493
490	/** Remove one manager from manager list */	494	/** Remove one manager from manager list */
491	void async_destroy_manager(void)	495	void async_destroy_manager(void)
492	{	496	{
493	psthread_remove_manager();	497	psthread_remove_manager();
494	}	498	}
495		499
496	/** Initialize internal structures needed for async manager */	500	/** Initialize internal structures needed for async manager */

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/async.c @ 1653 – Rev 1470 → 1490