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;
 
/** 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.
 */
void 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);
}
 

Rev 1466	Rev 1470
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	__thread connection_t *PS_connection;	131	__thread connection_t *PS_connection;
132		132
133	/** Add microseconds to give timeval */	133	/** Add microseconds to give timeval */
134	static void tv_add(struct timeval *tv, suseconds_t usecs)	134	static void tv_add(struct timeval *tv, suseconds_t usecs)
135	{	135	{
136	tv->tv_sec += usecs / 1000000;	136	tv->tv_sec += usecs / 1000000;
137	tv->tv_usec += usecs % 1000000;	137	tv->tv_usec += usecs % 1000000;
138	if (tv->tv_usec > 1000000) {	138	if (tv->tv_usec > 1000000) {
139	tv->tv_sec++;	139	tv->tv_sec++;
140	tv->tv_usec -= 1000000;	140	tv->tv_usec -= 1000000;
141	}	141	}
142	}	142	}
143		143
144	/** Subtract 2 timevals, return microseconds difference */	144	/** Subtract 2 timevals, return microseconds difference */
145	static suseconds_t tv_sub(struct timeval tv1, struct timeval tv2)	145	static suseconds_t tv_sub(struct timeval tv1, struct timeval tv2)
146	{	146	{
147	suseconds_t result;	147	suseconds_t result;
148		148
149	result = tv1->tv_usec - tv2->tv_usec;	149	result = tv1->tv_usec - tv2->tv_usec;
150	result += (tv1->tv_sec - tv2->tv_sec) * 1000000;	150	result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
151		151
152	return result;	152	return result;
153	}	153	}
154		154
155	/** Compare timeval	155	/** Compare timeval
156	*	156	*
157	* @return 1 if tv1 > tv2, otherwise 0	157	* @return 1 if tv1 > tv2, otherwise 0
158	*/	158	*/
159	static int tv_gt(struct timeval tv1, struct timeval tv2)	159	static int tv_gt(struct timeval tv1, struct timeval tv2)
160	{	160	{
161	if (tv1->tv_sec > tv2->tv_sec)	161	if (tv1->tv_sec > tv2->tv_sec)
162	return 1;	162	return 1;
163	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)	163	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
164	return 1;	164	return 1;
165	return 0;	165	return 0;
166	}	166	}
167	static int tv_gteq(struct timeval tv1, struct timeval tv2)	167	static int tv_gteq(struct timeval tv1, struct timeval tv2)
168	{	168	{
169	if (tv1->tv_sec > tv2->tv_sec)	169	if (tv1->tv_sec > tv2->tv_sec)
170	return 1;	170	return 1;
171	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)	171	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
172	return 1;	172	return 1;
173	return 0;	173	return 0;
174	}	174	}
175		175
176	/* Hash table functions */	176	/* Hash table functions */
177	#define CONN_HASH_TABLE_CHAINS 32	177	#define CONN_HASH_TABLE_CHAINS 32
178		178
179	static hash_index_t conn_hash(unsigned long *key)	179	static hash_index_t conn_hash(unsigned long *key)
180	{	180	{
181	assert(key);	181	assert(key);
182	return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;	182	return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
183	}	183	}
184		184
185	static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)	185	static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
186	{	186	{
187	connection_t *hs;	187	connection_t *hs;
188		188
189	hs = hash_table_get_instance(item, connection_t, link);	189	hs = hash_table_get_instance(item, connection_t, link);
190		190
191	return key[0] == hs->in_phone_hash;	191	return key[0] == hs->in_phone_hash;
192	}	192	}
193		193
194	static void conn_remove(link_t *item)	194	static void conn_remove(link_t *item)
195	{	195	{
196	free(hash_table_get_instance(item, connection_t, link));	196	free(hash_table_get_instance(item, connection_t, link));
197	}	197	}
198		198
199		199
200	/** Operations for NS hash table. */	200	/** Operations for NS hash table. */
201	static hash_table_operations_t conn_hash_table_ops = {	201	static hash_table_operations_t conn_hash_table_ops = {
202	.hash = conn_hash,	202	.hash = conn_hash,
203	.compare = conn_compare,	203	.compare = conn_compare,
204	.remove_callback = conn_remove	204	.remove_callback = conn_remove
205	};	205	};
206		206
207	/*************************************************/	207	/*************************************************/
208		208
209	/** Try to route a call to an appropriate connection thread	209	/** Try to route a call to an appropriate connection thread
210	*	210	*
211	*/	211	*/
212	static int route_call(ipc_callid_t callid, ipc_call_t *call)	212	static int route_call(ipc_callid_t callid, ipc_call_t *call)
213	{	213	{
214	connection_t *conn;	214	connection_t *conn;
215	msg_t *msg;	215	msg_t *msg;
216	link_t *hlp;	216	link_t *hlp;
217	unsigned long key;	217	unsigned long key;
218		218
219	futex_down(&async_futex);	219	futex_down(&async_futex);
220		220
221	key = call->in_phone_hash;	221	key = call->in_phone_hash;
222	hlp = hash_table_find(&conn_hash_table, &key);	222	hlp = hash_table_find(&conn_hash_table, &key);
223	if (!hlp) {	223	if (!hlp) {
224	futex_up(&async_futex);	224	futex_up(&async_futex);
225	return 0;	225	return 0;
226	}	226	}
227	conn = hash_table_get_instance(hlp, connection_t, link);	227	conn = hash_table_get_instance(hlp, connection_t, link);
228		228
229	msg = malloc(sizeof(*msg));	229	msg = malloc(sizeof(*msg));
230	msg->callid = callid;	230	msg->callid = callid;
231	msg->call = *call;	231	msg->call = *call;
232	list_append(&msg->link, &conn->msg_queue);	232	list_append(&msg->link, &conn->msg_queue);
233		233
234	if (!conn->active) {	234	if (!conn->active) {
235	conn->active = 1;	235	conn->active = 1;
236	psthread_add_ready(conn->ptid);	236	psthread_add_ready(conn->ptid);
237	}	237	}
238		238
239	futex_up(&async_futex);	239	futex_up(&async_futex);
240		240
241	return 1;	241	return 1;
242	}	242	}
243		243
244	/** Return new incoming message for current(thread-local) connection */	244	/** Return new incoming message for current(thread-local) connection */
245	ipc_callid_t async_get_call(ipc_call_t *call)	245	ipc_callid_t async_get_call(ipc_call_t *call)
246	{	246	{
247	msg_t *msg;	247	msg_t *msg;
248	ipc_callid_t callid;	248	ipc_callid_t callid;
249	connection_t *conn;	-
250		249
251	assert(PS_connection);	250	assert(PS_connection);
252		251
253	futex_down(&async_futex);	252	futex_down(&async_futex);
254		253
255	conn = PS_connection;	-
256	/* If nothing in queue, wait until something appears */	254	/* If nothing in queue, wait until something appears */
257	if (list_empty(&conn->msg_queue)) {	255	if (list_empty(&PS_connection->msg_queue)) {
258	conn->active = 0;	256	PS_connection->active = 0;
259	psthread_schedule_next_adv(PS_TO_MANAGER);	257	psthread_schedule_next_adv(PS_TO_MANAGER);
260	}	258	}
261		259
262	msg = list_get_instance(conn->msg_queue.next, msg_t, link);	260	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
263	list_remove(&msg->link);	261	list_remove(&msg->link);
264	callid = msg->callid;	262	callid = msg->callid;
265	*call = msg->call;	263	*call = msg->call;
266	free(msg);	264	free(msg);
267		265
268	futex_up(&async_futex);	266	futex_up(&async_futex);
269	return callid;	267	return callid;
270	}	268	}
271		269
272	/** Thread function that gets created on new connection	270	/** Thread function that gets created on new connection
273	*	271	*
274	* This function is defined as a weak symbol - to be redefined in	272	* This function is defined as a weak symbol - to be redefined in
275	* user code.	273	* user code.
276	*/	274	*/
277	void client_connection(ipc_callid_t callid, ipc_call_t *call)	275	void client_connection(ipc_callid_t callid, ipc_call_t *call)
278	{	276	{
279	ipc_answer_fast(callid, ENOENT, 0, 0);	277	ipc_answer_fast(callid, ENOENT, 0, 0);
280	}	278	}
281		279
282	/** Function that gets called on interrupt receival	280	/** Function that gets called on interrupt receival
283	*	281	*
284	* This function is defined as a weak symbol - to be redefined in	282	* This function is defined as a weak symbol - to be redefined in
285	* user code.	283	* user code.
286	*/	284	*/
287	void interrupt_received(ipc_call_t *call)	285	void interrupt_received(ipc_call_t *call)
288	{	286	{
289	}	287	}
290		288
291		289
292	/** Wrapper for client connection thread	290	/** Wrapper for client connection thread
293	*	291	*
294	* When new connection arrives, thread with this function is created.	292	* When new connection arrives, thread with this function is created.
295	* It calls client_connection and does final cleanup.	293	* It calls client_connection and does final cleanup.
296	*	294	*
297	* @parameter arg Connection structure pointer	295	* @parameter arg Connection structure pointer
298	*/	296	*/
299	static int connection_thread(void *arg)	297	static int connection_thread(void *arg)
300	{	298	{
301	unsigned long key;	299	unsigned long key;
302	msg_t *msg;	300	msg_t *msg;
303	connection_t *conn;	-
304		301
305	/* Setup thread local connection pointer */	302	/* Setup thread local connection pointer */
306	PS_connection = (connection_t *)arg;	303	PS_connection = (connection_t *)arg;
307	conn = PS_connection;	-
308	conn->cthread(conn->callid, &conn->call);	304	PS_connection->cthread(PS_connection->callid, &PS_connection->call);
309		305
310	/* Remove myself from connection hash table */	306	/* Remove myself from connection hash table */
311	futex_down(&async_futex);	307	futex_down(&async_futex);
312	key = conn->in_phone_hash;	308	key = PS_connection->in_phone_hash;
313	hash_table_remove(&conn_hash_table, &key, 1);	309	hash_table_remove(&conn_hash_table, &key, 1);
314	futex_up(&async_futex);	310	futex_up(&async_futex);
315	/* Answer all remaining messages with ehangup */	311	/* Answer all remaining messages with ehangup */
316	while (!list_empty(&conn->msg_queue)) {	312	while (!list_empty(&PS_connection->msg_queue)) {
317	msg = list_get_instance(conn->msg_queue.next, msg_t, link);	313	msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
318	list_remove(&msg->link);	314	list_remove(&msg->link);
319	ipc_answer_fast(msg->callid, EHANGUP, 0, 0);	315	ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
320	free(msg);	316	free(msg);
321	}	317	}
322	}	318	}
323		319
324	/** Create new thread for a new connection	320	/** Create new thread for a new connection
325	*	321	*
326	* Creates new thread for connection, fills in connection	322	* Creates new thread for connection, fills in connection
327	* structures and inserts it into the hash table, so that	323	* structures and inserts it into the hash table, so that
328	* later we can easily do routing of messages to particular	324	* later we can easily do routing of messages to particular
329	* threads.	325	* threads.
330	*	326	*
331	* @param in_phone_hash Identification of the incoming connection	327	* @param in_phone_hash Identification of the incoming connection
332	* @param callid Callid of the IPC_M_CONNECT_ME_TO packet	328	* @param callid Callid of the IPC_M_CONNECT_ME_TO packet
333	* @param call Call data of the opening packet	329	* @param call Call data of the opening packet
334	* @param cthread Thread function that should be called upon	330	* @param cthread Thread function that should be called upon
335	* opening the connection	331	* opening the connection
336	* @return New thread id	332	* @return New thread id
337	*/	333	*/
338	pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,	334	pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,
339	ipc_call_t *call,	335	ipc_call_t *call,
340	void (cthread)(ipc_callid_t,ipc_call_t ))	336	void (cthread)(ipc_callid_t,ipc_call_t ))
341	{	337	{
342	pstid_t ptid;	338	pstid_t ptid;
343	connection_t *conn;	339	connection_t *conn;
344	unsigned long key;	340	unsigned long key;
345		341
346	conn = malloc(sizeof(*conn));	342	conn = malloc(sizeof(*conn));
347	if (!conn) {	343	if (!conn) {
348	ipc_answer_fast(callid, ENOMEM, 0, 0);	344	ipc_answer_fast(callid, ENOMEM, 0, 0);
349	return NULL;	345	return NULL;
350	}	346	}
351	conn->in_phone_hash = in_phone_hash;	347	conn->in_phone_hash = in_phone_hash;
352	list_initialize(&conn->msg_queue);	348	list_initialize(&conn->msg_queue);
353	conn->ptid = psthread_create(connection_thread, conn);	349	conn->ptid = psthread_create(connection_thread, conn);
354	conn->callid = callid;	350	conn->callid = callid;
355	if (call)	351	if (call)
356	conn->call = *call;	352	conn->call = *call;
357	conn->active = 1; /* We will activate it asap */	353	conn->active = 1; /* We will activate it asap */
358	conn->cthread = cthread;	354	conn->cthread = cthread;
359	list_initialize(&conn->link);	355	list_initialize(&conn->link);
360	if (!conn->ptid) {	356	if (!conn->ptid) {
361	free(conn);	357	free(conn);
362	ipc_answer_fast(callid, ENOMEM, 0, 0);	358	ipc_answer_fast(callid, ENOMEM, 0, 0);
363	return NULL;	359	return NULL;
364	}	360	}
365	key = conn->in_phone_hash;	361	key = conn->in_phone_hash;
366	futex_down(&async_futex);	362	futex_down(&async_futex);
367	/* Add connection to hash table */	363	/* Add connection to hash table */
368	hash_table_insert(&conn_hash_table, &key, &conn->link);	364	hash_table_insert(&conn_hash_table, &key, &conn->link);
369	futex_up(&async_futex);	365	futex_up(&async_futex);
370		366
371	psthread_add_ready(conn->ptid);	367	psthread_add_ready(conn->ptid);
372		368
373	return conn->ptid;	369	return conn->ptid;
374	}	370	}
375		371
376	/** Handle call that was received */	372	/** Handle call that was received */
377	static void handle_call(ipc_callid_t callid, ipc_call_t *call)	373	static void handle_call(ipc_callid_t callid, ipc_call_t *call)
378	{	374	{
379	/* Unrouted call - do some default behaviour */	375	/* Unrouted call - do some default behaviour */
380	switch (IPC_GET_METHOD(*call)) {	376	switch (IPC_GET_METHOD(*call)) {
381	case IPC_M_INTERRUPT:	377	case IPC_M_INTERRUPT:
382	interrupt_received(call);	378	interrupt_received(call);
383	return;	379	return;
384	case IPC_M_CONNECT_ME_TO:	380	case IPC_M_CONNECT_ME_TO:
385	/* Open new connection with thread etc. */	381	/* Open new connection with thread etc. */
386	async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);	382	async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
387	return;	383	return;
388	}	384	}
389		385
390	/* Try to route call through connection tables */	386	/* Try to route call through connection tables */
391	if (route_call(callid, call))	387	if (route_call(callid, call))
392	return;	388	return;
393		389
394	/* Unknown call from unknown phone - hang it up */	390	/* Unknown call from unknown phone - hang it up */
395	ipc_answer_fast(callid, EHANGUP, 0, 0);	391	ipc_answer_fast(callid, EHANGUP, 0, 0);
396	}	392	}
397		393
398	/** Fire all timeouts that expired */	394	/** Fire all timeouts that expired */
399	static void handle_expired_timeouts(void)	395	static void handle_expired_timeouts(void)
400	{	396	{
401	struct timeval tv;	397	struct timeval tv;
402	amsg_t *amsg;	398	amsg_t *amsg;
403	link_t *cur;	399	link_t *cur;
404		400
405	gettimeofday(&tv,NULL);	401	gettimeofday(&tv,NULL);
406	futex_down(&async_futex);	402	futex_down(&async_futex);
407		403
408	cur = timeout_list.next;	404	cur = timeout_list.next;
409	while (cur != &timeout_list) {	405	while (cur != &timeout_list) {
410	amsg = list_get_instance(cur,amsg_t,link);	406	amsg = list_get_instance(cur,amsg_t,link);
411	if (tv_gt(&amsg->expires, &tv))	407	if (tv_gt(&amsg->expires, &tv))
412	break;	408	break;
413	cur = cur->next;	409	cur = cur->next;
414	list_remove(&amsg->link);	410	list_remove(&amsg->link);
415	amsg->has_timeout = 0;	411	amsg->has_timeout = 0;
416	/* Redundant condition? The thread should not	412	/* Redundant condition? The thread should not
417	* be active when it gets here.	413	* be active when it gets here.
418	*/	414	*/
419	if (!amsg->active) {	415	if (!amsg->active) {
420	amsg->active = 1;	416	amsg->active = 1;
421	psthread_add_ready(amsg->ptid);	417	psthread_add_ready(amsg->ptid);
422	}	418	}
423	}	419	}
424		420
425	futex_up(&async_futex);	421	futex_up(&async_futex);
426	}	422	}
427		423
428	/** Endless loop dispatching incoming calls and answers */	424	/** Endless loop dispatching incoming calls and answers */
429	int async_manager(void)	425	int async_manager(void)
430	{	426	{
431	ipc_call_t call;	427	ipc_call_t call;
432	ipc_callid_t callid;	428	ipc_callid_t callid;
433	int timeout;	429	int timeout;
434	amsg_t *amsg;	430	amsg_t *amsg;
435	struct timeval tv;	431	struct timeval tv;
436		432
437	while (1) {	433	while (1) {
438	if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {	434	if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
439	futex_up(&async_futex); /* async_futex is always held	435	futex_up(&async_futex); /* async_futex is always held
440	* when entering manager thread	436	* when entering manager thread
441	*/	437	*/
442	continue;	438	continue;
443	}	439	}
444	futex_down(&async_futex);	440	futex_down(&async_futex);
445	if (!list_empty(&timeout_list)) {	441	if (!list_empty(&timeout_list)) {
446	amsg = list_get_instance(timeout_list.next,amsg_t,link);	442	amsg = list_get_instance(timeout_list.next,amsg_t,link);
447	gettimeofday(&tv,NULL);	443	gettimeofday(&tv,NULL);
448	if (tv_gteq(&tv, &amsg->expires)) {	444	if (tv_gteq(&tv, &amsg->expires)) {
449	handle_expired_timeouts();	445	handle_expired_timeouts();
450	continue;	446	continue;
451	} else	447	} else
452	timeout = tv_sub(&amsg->expires, &tv);	448	timeout = tv_sub(&amsg->expires, &tv);
453	} else	449	} else
454	timeout = SYNCH_NO_TIMEOUT;	450	timeout = SYNCH_NO_TIMEOUT;
455	futex_up(&async_futex);	451	futex_up(&async_futex);
456		452
457	callid = ipc_wait_cycle(&call, timeout, SYNCH_BLOCKING);	453	callid = ipc_wait_cycle(&call, timeout, SYNCH_BLOCKING);
458		454
459	if (!callid) {	455	if (!callid) {
460	handle_expired_timeouts();	456	handle_expired_timeouts();
461	continue;	457	continue;
462	}	458	}
463		459
464	if (callid & IPC_CALLID_ANSWERED)	460	if (callid & IPC_CALLID_ANSWERED)
465	continue;	461	continue;
466		462
467	handle_call(callid, &call);	463	handle_call(callid, &call);
468	}	464	}
469	}	465	}
470		466
471	/** Function to start async_manager as a standalone thread	467	/** Function to start async_manager as a standalone thread
472	*	468	*
473	* When more kernel threads are used, one async manager should	469	* When more kernel threads are used, one async manager should
474	* exist per thread. The particular implementation may change,	470	* exist per thread. The particular implementation may change,
475	* currently one async_manager is started automatically per kernel	471	* currently one async_manager is started automatically per kernel
476	* thread except main thread.	472	* thread except main thread.
477	*/	473	*/
478	static int async_manager_thread(void *arg)	474	static int async_manager_thread(void *arg)
479	{	475	{
480	futex_up(&async_futex); /* async_futex is always locked when entering	476	futex_up(&async_futex); /* async_futex is always locked when entering
481	* manager */	477	* manager */
482	async_manager();	478	async_manager();
483	}	479	}
484		480
485	/** Add one manager to manager list */	481	/** Add one manager to manager list */
486	void async_create_manager(void)	482	void async_create_manager(void)
487	{	483	{
488	pstid_t ptid;	484	pstid_t ptid;
489		485
490	ptid = psthread_create(async_manager_thread, NULL);	486	ptid = psthread_create(async_manager_thread, NULL);
491	psthread_add_manager(ptid);	487	psthread_add_manager(ptid);
492	}	488	}
493		489
494	/** Remove one manager from manager list */	490	/** Remove one manager from manager list */
495	void async_destroy_manager(void)	491	void async_destroy_manager(void)
496	{	492	{
497	psthread_remove_manager();	493	psthread_remove_manager();
498	}	494	}
499		495
500	/** Initialize internal structures needed for async manager */	496	/** Initialize internal structures needed for async manager */

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/async.c @ 1653 – Rev 1466 → 1470