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  1. /*
  2.  * Copyright (C) 2006 Ondrej Palkovsky
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  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
  15.  *   derived from this software without specific prior written permission.
  16.  *
  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
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  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
  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
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /**
  30.  * Asynchronous library
  31.  *
  32.  * The aim of this library is facilitating writing programs utilizing
  33.  * the asynchronous nature of Helenos IPC, yet using a normal way
  34.  * of programming.
  35.  *
  36.  * You should be able to write very simple multithreaded programs,
  37.  * the async framework will automatically take care of most synchronization
  38.  * problems.
  39.  *
  40.  * Default semantics:
  41.  * - send() - send asynchronously. If the kernel refuses to send more
  42.  *            messages, [ try to get responses from kernel, if nothing
  43.  *            found, might try synchronous ]
  44.  *
  45.  * Example of use:
  46.  *
  47.  * 1) Multithreaded client application
  48.  *  create_thread(thread1);
  49.  *  create_thread(thread2);
  50.  *  ...
  51.  *  
  52.  *  thread1() {
  53.  *        conn = ipc_connect_me_to();
  54.  *        c1 = send(conn);
  55.  *        c2 = send(conn);
  56.  *        wait_for(c1);
  57.  *        wait_for(c2);
  58.  *  }
  59.  *
  60.  *
  61.  * 2) Multithreaded server application
  62.  * main() {
  63.  *      async_manager();
  64.  * }
  65.  *
  66.  *
  67.  * client_connection(icallid, *icall) {
  68.  *       if (want_refuse) {
  69.  *           ipc_answer_fast(icallid, ELIMIT, 0, 0);
  70.  *           return;
  71.  *       }
  72.  *       ipc_answer_fast(icallid, 0, 0, 0);
  73.  *
  74.  *       callid = async_get_call(&call);
  75.  *       handle(callid, call);
  76.  *       ipc_answer_fast(callid, 1,2,3);
  77.  *
  78.  *       callid = async_get_call(&call);
  79.  *       ....
  80.  * }
  81.  *
  82.  * TODO: Detaching/joining dead psthreads?
  83.  */
  84. #include <futex.h>
  85. #include <async.h>
  86. #include <psthread.h>
  87. #include <stdio.h>
  88. #include <libadt/hash_table.h>
  89. #include <libadt/list.h>
  90. #include <ipc/ipc.h>
  91. #include <assert.h>
  92. #include <errno.h>
  93. #include <time.h>
  94. #include <arch/barrier.h>
  95.  
  96. atomic_t async_futex = FUTEX_INITIALIZER;
  97. static hash_table_t conn_hash_table;
  98. static LIST_INITIALIZE(timeout_list);
  99.  
  100. typedef struct {
  101.     struct timeval expires;      /**< Expiration time for waiting thread */
  102.     int inlist;             /**< If true, this struct is in timeout list */
  103.     link_t link;
  104.  
  105.     pstid_t ptid;                /**< Thread waiting for this message */
  106.     int active;                  /**< If this thread is currently active */
  107.     int timedout;                /**< If true, we timed out */
  108. } awaiter_t;
  109.  
  110. typedef struct {
  111.     awaiter_t wdata;
  112.  
  113.     int done;                    /**< If reply was received */
  114.     ipc_call_t *dataptr;         /**< Pointer where the answer data
  115.                       *   is stored */
  116.     ipcarg_t retval;
  117. } amsg_t;
  118.  
  119. typedef struct {
  120.     link_t link;
  121.     ipc_callid_t callid;
  122.     ipc_call_t call;
  123. } msg_t;
  124.  
  125. typedef struct {
  126.     awaiter_t wdata;
  127.  
  128.     link_t link;             /**< Hash table link */
  129.     ipcarg_t in_phone_hash;  /**< Incoming phone hash. */
  130.     link_t msg_queue;        /**< Messages that should be delivered to this thread */
  131.     /* Structures for connection opening packet */
  132.     ipc_callid_t callid;
  133.     ipc_call_t call;
  134.     void (*cthread)(ipc_callid_t,ipc_call_t *);
  135. } connection_t;
  136.  
  137.  
  138. __thread connection_t *PS_connection;
  139.  
  140. static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);
  141. static async_client_conn_t client_connection = default_client_connection;
  142.  
  143. /** Add microseconds to give timeval */
  144. static void tv_add(struct timeval *tv, suseconds_t usecs)
  145. {
  146.     tv->tv_sec += usecs / 1000000;
  147.     tv->tv_usec += usecs % 1000000;
  148.     if (tv->tv_usec > 1000000) {
  149.         tv->tv_sec++;
  150.         tv->tv_usec -= 1000000;
  151.     }
  152. }
  153.  
  154. /** Subtract 2 timevals, return microseconds difference */
  155. static suseconds_t tv_sub(struct timeval *tv1, struct timeval *tv2)
  156. {
  157.     suseconds_t result;
  158.  
  159.     result = tv1->tv_usec - tv2->tv_usec;
  160.     result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
  161.  
  162.     return result;
  163. }
  164.  
  165. /** Compare timeval
  166.  *
  167.  * @return 1 if tv1 > tv2, otherwise 0
  168.  */
  169. static int tv_gt(struct timeval *tv1, struct timeval *tv2)
  170. {
  171.     if (tv1->tv_sec > tv2->tv_sec)
  172.         return 1;
  173.     if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
  174.         return 1;
  175.     return 0;
  176. }
  177. static int tv_gteq(struct timeval *tv1, struct timeval *tv2)
  178. {
  179.     if (tv1->tv_sec > tv2->tv_sec)
  180.         return 1;
  181.     if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
  182.         return 1;
  183.     return 0;
  184. }
  185.  
  186. /* Hash table functions */
  187. #define CONN_HASH_TABLE_CHAINS  32
  188.  
  189. static hash_index_t conn_hash(unsigned long *key)
  190. {
  191.     assert(key);
  192.     return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
  193. }
  194.  
  195. static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
  196. {
  197.     connection_t *hs;
  198.  
  199.     hs = hash_table_get_instance(item, connection_t, link);
  200.    
  201.     return key[0] == hs->in_phone_hash;
  202. }
  203.  
  204. static void conn_remove(link_t *item)
  205. {
  206.     free(hash_table_get_instance(item, connection_t, link));
  207. }
  208.  
  209.  
  210. /** Operations for NS hash table. */
  211. static hash_table_operations_t conn_hash_table_ops = {
  212.     .hash = conn_hash,
  213.     .compare = conn_compare,
  214.     .remove_callback = conn_remove
  215. };
  216.  
  217. /** Insert sort timeout msg into timeouts list
  218.  *
  219.  * Assume async_futex is held
  220.  */
  221. static void insert_timeout(awaiter_t *wd)
  222. {
  223.     link_t *tmp;
  224.     awaiter_t *cur;
  225.  
  226.     wd->timedout = 0;
  227.  
  228.     tmp = timeout_list.next;
  229.     while (tmp != &timeout_list) {
  230.         cur = list_get_instance(tmp, awaiter_t, link);
  231.         if (tv_gteq(&cur->expires, &wd->expires))
  232.             break;
  233.         tmp = tmp->next;
  234.     }
  235.     list_append(&wd->link, tmp);
  236. }
  237.  
  238. /*************************************************/
  239.  
  240. /** Try to route a call to an appropriate connection thread
  241.  *
  242.  */
  243. static int route_call(ipc_callid_t callid, ipc_call_t *call)
  244. {
  245.     connection_t *conn;
  246.     msg_t *msg;
  247.     link_t *hlp;
  248.     unsigned long key;
  249.  
  250.     futex_down(&async_futex);
  251.  
  252.     key = call->in_phone_hash;
  253.     hlp = hash_table_find(&conn_hash_table, &key);
  254.     if (!hlp) {
  255.         futex_up(&async_futex);
  256.         return 0;
  257.     }
  258.     conn = hash_table_get_instance(hlp, connection_t, link);
  259.  
  260.     msg = malloc(sizeof(*msg));
  261.     msg->callid = callid;
  262.     msg->call = *call;
  263.     list_append(&msg->link, &conn->msg_queue);
  264.    
  265.     /* If the call is waiting for event, run it */
  266.     if (!conn->wdata.active) {
  267.         /* If in timeout list, remove it */
  268.         if (conn->wdata.inlist) {
  269.             conn->wdata.inlist = 0;
  270.             list_remove(&conn->wdata.link);
  271.         }
  272.         conn->wdata.active = 1;
  273.         psthread_add_ready(conn->wdata.ptid);
  274.     }
  275.  
  276.     futex_up(&async_futex);
  277.  
  278.     return 1;
  279. }
  280.  
  281. /** Return new incoming message for current(thread-local) connection */
  282. ipc_callid_t async_get_call_timeout(ipc_call_t *call, suseconds_t usecs)
  283. {
  284.     msg_t *msg;
  285.     ipc_callid_t callid;
  286.    
  287.     assert(PS_connection);
  288.  
  289.     futex_down(&async_futex);
  290.  
  291.     if (usecs) {
  292.         gettimeofday(&PS_connection->wdata.expires, NULL);
  293.         tv_add(&PS_connection->wdata.expires, usecs);
  294.     } else {
  295.         PS_connection->wdata.inlist = 0;
  296.     }
  297.     /* If nothing in queue, wait until something appears */
  298.     while (list_empty(&PS_connection->msg_queue)) {
  299.         if (usecs) {
  300.             PS_connection->wdata.inlist = 1;
  301.             insert_timeout(&PS_connection->wdata);
  302.         }
  303.         PS_connection->wdata.active = 0;
  304.         psthread_schedule_next_adv(PS_TO_MANAGER);
  305.         /* Futex is up after getting back from async_manager
  306.          * get it again */
  307.         futex_down(&async_futex);
  308.         if (usecs && PS_connection->wdata.timedout && \
  309.             list_empty(&PS_connection->msg_queue)) {
  310.             /* If we timed out-> exit */
  311.             futex_up(&async_futex);
  312.             return 0;
  313.         }
  314.     }
  315.    
  316.     msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
  317.     list_remove(&msg->link);
  318.     callid = msg->callid;
  319.     *call = msg->call;
  320.     free(msg);
  321.    
  322.     futex_up(&async_futex);
  323.     return callid;
  324. }
  325.  
  326. /** Thread function that gets created on new connection
  327.  *
  328.  * This function is defined as a weak symbol - to be redefined in
  329.  * user code.
  330.  */
  331. static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
  332. {
  333.     ipc_answer_fast(callid, ENOENT, 0, 0);
  334. }
  335.  
  336. /** Function that gets called on interrupt receival
  337.  *
  338.  * This function is defined as a weak symbol - to be redefined in
  339.  * user code.
  340.  */
  341. void interrupt_received(ipc_call_t *call)
  342. {
  343. }
  344.  
  345.  
  346. /** Wrapper for client connection thread
  347.  *
  348.  * When new connection arrives, thread with this function is created.
  349.  * It calls client_connection and does final cleanup.
  350.  *
  351.  * @parameter arg Connection structure pointer
  352.  */
  353. static int connection_thread(void  *arg)
  354. {
  355.     unsigned long key;
  356.     msg_t *msg;
  357.  
  358.     /* Setup thread local connection pointer */
  359.     PS_connection = (connection_t *)arg;
  360.     PS_connection->cthread(PS_connection->callid, &PS_connection->call);
  361.  
  362.     /* Remove myself from connection hash table */
  363.     futex_down(&async_futex);
  364.     key = PS_connection->in_phone_hash;
  365.     hash_table_remove(&conn_hash_table, &key, 1);
  366.     futex_up(&async_futex);
  367.     /* Answer all remaining messages with ehangup */
  368.     while (!list_empty(&PS_connection->msg_queue)) {
  369.         msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
  370.         list_remove(&msg->link);
  371.         ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
  372.         free(msg);
  373.     }
  374. }
  375.  
  376. /** Create new thread for a new connection
  377.  *
  378.  * Creates new thread for connection, fills in connection
  379.  * structures and inserts it into the hash table, so that
  380.  * later we can easily do routing of messages to particular
  381.  * threads.
  382.  *
  383.  * @param in_phone_hash Identification of the incoming connection
  384.  * @param callid Callid of the IPC_M_CONNECT_ME_TO packet
  385.  * @param call Call data of the opening packet
  386.  * @param cthread Thread function that should be called upon
  387.  *                opening the connection
  388.  * @return New thread id
  389.  */
  390. pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,
  391.                  ipc_call_t *call,
  392.                  void (*cthread)(ipc_callid_t,ipc_call_t *))
  393. {
  394.     pstid_t ptid;
  395.     connection_t *conn;
  396.     unsigned long key;
  397.  
  398.     conn = malloc(sizeof(*conn));
  399.     if (!conn) {
  400.         ipc_answer_fast(callid, ENOMEM, 0, 0);
  401.         return NULL;
  402.     }
  403.     conn->in_phone_hash = in_phone_hash;
  404.     list_initialize(&conn->msg_queue);
  405.     conn->callid = callid;
  406.     if (call)
  407.         conn->call = *call;
  408.     conn->wdata.active = 1; /* We will activate it asap */
  409.     conn->cthread = cthread;
  410.  
  411.     conn->wdata.ptid = psthread_create(connection_thread, conn);
  412.     if (!conn->wdata.ptid) {
  413.         free(conn);
  414.         ipc_answer_fast(callid, ENOMEM, 0, 0);
  415.         return NULL;
  416.     }
  417.     /* Add connection to hash table */
  418.     key = conn->in_phone_hash;
  419.     futex_down(&async_futex);
  420.     hash_table_insert(&conn_hash_table, &key, &conn->link);
  421.     futex_up(&async_futex);
  422.  
  423.     psthread_add_ready(conn->wdata.ptid);
  424.  
  425.     return conn->wdata.ptid;
  426. }
  427.  
  428. /** Handle call that was received */
  429. static void handle_call(ipc_callid_t callid, ipc_call_t *call)
  430. {
  431.     /* Unrouted call - do some default behaviour */
  432.     switch (IPC_GET_METHOD(*call)) {
  433.     case IPC_M_INTERRUPT:
  434.         interrupt_received(call);
  435.         return;
  436.     case IPC_M_CONNECT_ME_TO:
  437.         /* Open new connection with thread etc. */
  438.         async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
  439.         return;
  440.     }
  441.  
  442.     /* Try to route call through connection tables */
  443.     if (route_call(callid, call))
  444.         return;
  445.  
  446.     /* Unknown call from unknown phone - hang it up */
  447.     ipc_answer_fast(callid, EHANGUP, 0, 0);
  448. }
  449.  
  450. /** Fire all timeouts that expired */
  451. static void handle_expired_timeouts(void)
  452. {
  453.     struct timeval tv;
  454.     awaiter_t *waiter;
  455.     link_t *cur;
  456.  
  457.     gettimeofday(&tv,NULL);
  458.     futex_down(&async_futex);
  459.  
  460.     cur = timeout_list.next;
  461.     while (cur != &timeout_list) {
  462.         waiter = list_get_instance(cur,awaiter_t,link);
  463.         if (tv_gt(&waiter->expires, &tv))
  464.             break;
  465.         cur = cur->next;
  466.         list_remove(&waiter->link);
  467.         waiter->inlist = 0;
  468.         waiter->timedout = 1;
  469.         /* Redundant condition? The thread should not
  470.          * be active when it gets here.
  471.          */
  472.         if (!waiter->active) {
  473.             waiter->active = 1;
  474.             psthread_add_ready(waiter->ptid);
  475.         }
  476.     }
  477.  
  478.     futex_up(&async_futex);
  479. }
  480.  
  481. /** Endless loop dispatching incoming calls and answers */
  482. int async_manager(void)
  483. {
  484.     ipc_call_t call;
  485.     ipc_callid_t callid;
  486.     int timeout;
  487.     awaiter_t *waiter;
  488.     struct timeval tv;
  489.  
  490.     while (1) {
  491.         if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
  492.             futex_up(&async_futex); /* async_futex is always held
  493.                         * when entering manager thread
  494.                         */
  495.             continue;
  496.         }
  497.         futex_down(&async_futex);
  498.         if (!list_empty(&timeout_list)) {
  499.             waiter = list_get_instance(timeout_list.next,awaiter_t,link);
  500.             gettimeofday(&tv,NULL);
  501.             if (tv_gteq(&tv, &waiter->expires)) {
  502.                 handle_expired_timeouts();
  503.                 continue;
  504.             } else
  505.                 timeout = tv_sub(&waiter->expires, &tv);
  506.         } else
  507.             timeout = SYNCH_NO_TIMEOUT;
  508.         futex_up(&async_futex);
  509.  
  510.         callid = ipc_wait_cycle(&call, timeout, SYNCH_BLOCKING);
  511.  
  512.         if (!callid) {
  513.             handle_expired_timeouts();
  514.             continue;
  515.         }
  516.  
  517.         if (callid & IPC_CALLID_ANSWERED)
  518.             continue;
  519.  
  520.         handle_call(callid, &call);
  521.     }
  522. }
  523.  
  524. /** Function to start async_manager as a standalone thread
  525.  *
  526.  * When more kernel threads are used, one async manager should
  527.  * exist per thread. The particular implementation may change,
  528.  * currently one async_manager is started automatically per kernel
  529.  * thread except main thread.
  530.  */
  531. static int async_manager_thread(void *arg)
  532. {
  533.     futex_up(&async_futex); /* async_futex is always locked when entering
  534.                 * manager */
  535.     async_manager();
  536. }
  537.  
  538. /** Add one manager to manager list */
  539. void async_create_manager(void)
  540. {
  541.     pstid_t ptid;
  542.  
  543.     ptid = psthread_create(async_manager_thread, NULL);
  544.     psthread_add_manager(ptid);
  545. }
  546.  
  547. /** Remove one manager from manager list */
  548. void async_destroy_manager(void)
  549. {
  550.     psthread_remove_manager();
  551. }
  552.  
  553. /** Initialize internal structures needed for async manager */
  554. int _async_init(void)
  555. {
  556.     if (!hash_table_create(&conn_hash_table, CONN_HASH_TABLE_CHAINS, 1, &conn_hash_table_ops)) {
  557.         printf("%s: cannot create hash table\n", "async");
  558.         return ENOMEM;
  559.     }
  560.    
  561. }
  562.  
  563. /** IPC handler for messages in async framework
  564.  *
  565.  * Notify thread that is waiting for this message, that it arrived
  566.  */
  567. static void reply_received(void *private, int retval,
  568.                ipc_call_t *data)
  569. {
  570.     amsg_t *msg = (amsg_t *) private;
  571.  
  572.     msg->retval = retval;
  573.  
  574.     futex_down(&async_futex);
  575.     /* Copy data after futex_down, just in case the
  576.      * call was detached
  577.      */
  578.     if (msg->dataptr)
  579.         *msg->dataptr = *data;
  580.  
  581.     write_barrier();
  582.     /* Remove message from timeout list */
  583.     if (msg->wdata.inlist)
  584.         list_remove(&msg->wdata.link);
  585.     msg->done = 1;
  586.     if (! msg->wdata.active) {
  587.         msg->wdata.active = 1;
  588.         psthread_add_ready(msg->wdata.ptid);
  589.     }
  590.     futex_up(&async_futex);
  591. }
  592.  
  593. /** Send message and return id of the sent message
  594.  *
  595.  * The return value can be used as input for async_wait() to wait
  596.  * for completion.
  597.  */
  598. aid_t async_send_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
  599.            ipc_call_t *dataptr)
  600. {
  601.     amsg_t *msg;
  602.  
  603.     msg = malloc(sizeof(*msg));
  604.     msg->done = 0;
  605.     msg->dataptr = dataptr;
  606.  
  607.     msg->wdata.active = 1; /* We may sleep in next method, but it
  608.                 * will use it's own mechanism */
  609.     ipc_call_async_2(phoneid,method,arg1,arg2,msg,reply_received);
  610.  
  611.     return (aid_t) msg;
  612. }
  613.  
  614. /** Wait for a message sent by async framework
  615.  *
  616.  * @param amsgid Message ID to wait for
  617.  * @param retval Pointer to variable where will be stored retval
  618.  *               of the answered message. If NULL, it is ignored.
  619.  *
  620.  */
  621. void async_wait_for(aid_t amsgid, ipcarg_t *retval)
  622. {
  623.     amsg_t *msg = (amsg_t *) amsgid;
  624.     connection_t *conn;
  625.  
  626.     futex_down(&async_futex);
  627.     if (msg->done) {
  628.         futex_up(&async_futex);
  629.         goto done;
  630.     }
  631.  
  632.     msg->wdata.ptid = psthread_get_id();
  633.     msg->wdata.active = 0;
  634.     msg->wdata.inlist = 0;
  635.     /* Leave locked async_futex when entering this function */
  636.     psthread_schedule_next_adv(PS_TO_MANAGER);
  637.     /* futex is up automatically after psthread_schedule_next...*/
  638. done:
  639.     if (retval)
  640.         *retval = msg->retval;
  641.     free(msg);
  642. }
  643.  
  644. /** Wait for a message sent by async framework with timeout
  645.  *
  646.  * @param amsgid Message ID to wait for
  647.  * @param retval Pointer to variable where will be stored retval
  648.  *               of the answered message. If NULL, it is ignored.
  649.  * @param timeout Timeout in usecs
  650.  * @return 0 on success, ETIMEOUT if timeout expired
  651.  *
  652.  */
  653. int async_wait_timeout(aid_t amsgid, ipcarg_t *retval, suseconds_t timeout)
  654. {
  655.     amsg_t *msg = (amsg_t *) amsgid;
  656.     connection_t *conn;
  657.  
  658.     futex_down(&async_futex);
  659.     if (msg->done) {
  660.         futex_up(&async_futex);
  661.         goto done;
  662.     }
  663.  
  664.     gettimeofday(&msg->wdata.expires, NULL);
  665.     tv_add(&msg->wdata.expires, timeout);
  666.  
  667.     msg->wdata.ptid = psthread_get_id();
  668.     msg->wdata.active = 0;
  669.     msg->wdata.inlist = 1;
  670.  
  671.     insert_timeout(&msg->wdata);
  672.  
  673.     /* Leave locked async_futex when entering this function */
  674.     psthread_schedule_next_adv(PS_TO_MANAGER);
  675.     /* futex is up automatically after psthread_schedule_next...*/
  676.  
  677.     if (!msg->done)
  678.         return ETIMEOUT;
  679.  
  680. done:
  681.     if (retval)
  682.         *retval = msg->retval;
  683.     free(msg);
  684.  
  685.     return 0;
  686. }
  687.  
  688. /** Wait specified time, but in the meantime handle incoming events
  689.  *
  690.  * @param timeout Time in microseconds to wait
  691.  */
  692. void async_usleep(suseconds_t timeout)
  693. {
  694.     amsg_t *msg;
  695.    
  696.     msg = malloc(sizeof(*msg));
  697.     if (!msg)
  698.         return;
  699.  
  700.     msg->wdata.ptid = psthread_get_id();
  701.     msg->wdata.inlist = 1;
  702.     msg->wdata.active = 0;
  703.  
  704.     gettimeofday(&msg->wdata.expires, NULL);
  705.     tv_add(&msg->wdata.expires, timeout);
  706.  
  707.     futex_down(&async_futex);
  708.     insert_timeout(&msg->wdata);
  709.     /* Leave locked async_futex when entering this function */
  710.     psthread_schedule_next_adv(PS_TO_MANAGER);
  711.     /* futex is up automatically after psthread_schedule_next...*/
  712.     free(msg);
  713. }
  714.  
  715. /** Set function that is called, IPC_M_CONNECT_ME_TO is received
  716.  *
  717.  * @param conn Function that will form new psthread.
  718.  */
  719. void async_set_client_connection(async_client_conn_t conn)
  720. {
  721.     client_connection = conn;
  722. }
  723.