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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.     if (usecs < 0) /* TODO: let it get through the ipc_call once */
  290.         return 0;
  291.  
  292.     futex_down(&async_futex);
  293.  
  294.     if (usecs) {
  295.         gettimeofday(&PS_connection->wdata.expires, NULL);
  296.         tv_add(&PS_connection->wdata.expires, usecs);
  297.     } else {
  298.         PS_connection->wdata.inlist = 0;
  299.     }
  300.     /* If nothing in queue, wait until something appears */
  301.     while (list_empty(&PS_connection->msg_queue)) {
  302.         if (usecs) {
  303.             PS_connection->wdata.inlist = 1;
  304.             insert_timeout(&PS_connection->wdata);
  305.         }
  306.         PS_connection->wdata.active = 0;
  307.         psthread_schedule_next_adv(PS_TO_MANAGER);
  308.         /* Futex is up after getting back from async_manager
  309.          * get it again */
  310.         futex_down(&async_futex);
  311.         if (usecs && PS_connection->wdata.timedout && \
  312.             list_empty(&PS_connection->msg_queue)) {
  313.             /* If we timed out-> exit */
  314.             futex_up(&async_futex);
  315.             return 0;
  316.         }
  317.     }
  318.    
  319.     msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
  320.     list_remove(&msg->link);
  321.     callid = msg->callid;
  322.     *call = msg->call;
  323.     free(msg);
  324.    
  325.     futex_up(&async_futex);
  326.     return callid;
  327. }
  328.  
  329. /** Thread function that gets created on new connection
  330.  *
  331.  * This function is defined as a weak symbol - to be redefined in
  332.  * user code.
  333.  */
  334. static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
  335. {
  336.     ipc_answer_fast(callid, ENOENT, 0, 0);
  337. }
  338.  
  339. /** Function that gets called on interrupt receival
  340.  *
  341.  * This function is defined as a weak symbol - to be redefined in
  342.  * user code.
  343.  */
  344. void interrupt_received(ipc_call_t *call)
  345. {
  346. }
  347.  
  348.  
  349. /** Wrapper for client connection thread
  350.  *
  351.  * When new connection arrives, thread with this function is created.
  352.  * It calls client_connection and does final cleanup.
  353.  *
  354.  * @parameter arg Connection structure pointer
  355.  */
  356. static int connection_thread(void  *arg)
  357. {
  358.     unsigned long key;
  359.     msg_t *msg;
  360.  
  361.     /* Setup thread local connection pointer */
  362.     PS_connection = (connection_t *)arg;
  363.     PS_connection->cthread(PS_connection->callid, &PS_connection->call);
  364.  
  365.     /* Remove myself from connection hash table */
  366.     futex_down(&async_futex);
  367.     key = PS_connection->in_phone_hash;
  368.     hash_table_remove(&conn_hash_table, &key, 1);
  369.     futex_up(&async_futex);
  370.     /* Answer all remaining messages with ehangup */
  371.     while (!list_empty(&PS_connection->msg_queue)) {
  372.         msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
  373.         list_remove(&msg->link);
  374.         ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
  375.         free(msg);
  376.     }
  377. }
  378.  
  379. /** Create new thread for a new connection
  380.  *
  381.  * Creates new thread for connection, fills in connection
  382.  * structures and inserts it into the hash table, so that
  383.  * later we can easily do routing of messages to particular
  384.  * threads.
  385.  *
  386.  * @param in_phone_hash Identification of the incoming connection
  387.  * @param callid Callid of the IPC_M_CONNECT_ME_TO packet
  388.  * @param call Call data of the opening packet
  389.  * @param cthread Thread function that should be called upon
  390.  *                opening the connection
  391.  * @return New thread id
  392.  */
  393. pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,
  394.                  ipc_call_t *call,
  395.                  void (*cthread)(ipc_callid_t,ipc_call_t *))
  396. {
  397.     pstid_t ptid;
  398.     connection_t *conn;
  399.     unsigned long key;
  400.  
  401.     conn = malloc(sizeof(*conn));
  402.     if (!conn) {
  403.         ipc_answer_fast(callid, ENOMEM, 0, 0);
  404.         return NULL;
  405.     }
  406.     conn->in_phone_hash = in_phone_hash;
  407.     list_initialize(&conn->msg_queue);
  408.     conn->callid = callid;
  409.     if (call)
  410.         conn->call = *call;
  411.     conn->wdata.active = 1; /* We will activate it asap */
  412.     conn->cthread = cthread;
  413.  
  414.     conn->wdata.ptid = psthread_create(connection_thread, conn);
  415.     if (!conn->wdata.ptid) {
  416.         free(conn);
  417.         ipc_answer_fast(callid, ENOMEM, 0, 0);
  418.         return NULL;
  419.     }
  420.     /* Add connection to hash table */
  421.     key = conn->in_phone_hash;
  422.     futex_down(&async_futex);
  423.     hash_table_insert(&conn_hash_table, &key, &conn->link);
  424.     futex_up(&async_futex);
  425.  
  426.     psthread_add_ready(conn->wdata.ptid);
  427.  
  428.     return conn->wdata.ptid;
  429. }
  430.  
  431. /** Handle call that was received */
  432. static void handle_call(ipc_callid_t callid, ipc_call_t *call)
  433. {
  434.     /* Unrouted call - do some default behaviour */
  435.     switch (IPC_GET_METHOD(*call)) {
  436.     case IPC_M_INTERRUPT:
  437.         interrupt_received(call);
  438.         return;
  439.     case IPC_M_CONNECT_ME_TO:
  440.         /* Open new connection with thread etc. */
  441.         async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
  442.         return;
  443.     }
  444.  
  445.     /* Try to route call through connection tables */
  446.     if (route_call(callid, call))
  447.         return;
  448.  
  449.     /* Unknown call from unknown phone - hang it up */
  450.     ipc_answer_fast(callid, EHANGUP, 0, 0);
  451. }
  452.  
  453. /** Fire all timeouts that expired */
  454. static void handle_expired_timeouts(void)
  455. {
  456.     struct timeval tv;
  457.     awaiter_t *waiter;
  458.     link_t *cur;
  459.  
  460.     gettimeofday(&tv,NULL);
  461.     futex_down(&async_futex);
  462.  
  463.     cur = timeout_list.next;
  464.     while (cur != &timeout_list) {
  465.         waiter = list_get_instance(cur,awaiter_t,link);
  466.         if (tv_gt(&waiter->expires, &tv))
  467.             break;
  468.         cur = cur->next;
  469.         list_remove(&waiter->link);
  470.         waiter->inlist = 0;
  471.         waiter->timedout = 1;
  472.         /* Redundant condition? The thread should not
  473.          * be active when it gets here.
  474.          */
  475.         if (!waiter->active) {
  476.             waiter->active = 1;
  477.             psthread_add_ready(waiter->ptid);
  478.         }
  479.     }
  480.  
  481.     futex_up(&async_futex);
  482. }
  483.  
  484. /** Endless loop dispatching incoming calls and answers */
  485. int async_manager(void)
  486. {
  487.     ipc_call_t call;
  488.     ipc_callid_t callid;
  489.     int timeout;
  490.     awaiter_t *waiter;
  491.     struct timeval tv;
  492.  
  493.     while (1) {
  494.         if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
  495.             futex_up(&async_futex); /* async_futex is always held
  496.                         * when entering manager thread
  497.                         */
  498.             continue;
  499.         }
  500.         futex_down(&async_futex);
  501.         if (!list_empty(&timeout_list)) {
  502.             waiter = list_get_instance(timeout_list.next,awaiter_t,link);
  503.             gettimeofday(&tv,NULL);
  504.             if (tv_gteq(&tv, &waiter->expires)) {
  505.                 handle_expired_timeouts();
  506.                 continue;
  507.             } else
  508.                 timeout = tv_sub(&waiter->expires, &tv);
  509.         } else
  510.             timeout = SYNCH_NO_TIMEOUT;
  511.         futex_up(&async_futex);
  512.  
  513.         callid = ipc_wait_cycle(&call, timeout, SYNCH_FLAGS_NONE);
  514.  
  515.         if (!callid) {
  516.             handle_expired_timeouts();
  517.             continue;
  518.         }
  519.  
  520.         if (callid & IPC_CALLID_ANSWERED)
  521.             continue;
  522.  
  523.         handle_call(callid, &call);
  524.     }
  525. }
  526.  
  527. /** Function to start async_manager as a standalone thread
  528.  *
  529.  * When more kernel threads are used, one async manager should
  530.  * exist per thread. The particular implementation may change,
  531.  * currently one async_manager is started automatically per kernel
  532.  * thread except main thread.
  533.  */
  534. static int async_manager_thread(void *arg)
  535. {
  536.     futex_up(&async_futex); /* async_futex is always locked when entering
  537.                 * manager */
  538.     async_manager();
  539. }
  540.  
  541. /** Add one manager to manager list */
  542. void async_create_manager(void)
  543. {
  544.     pstid_t ptid;
  545.  
  546.     ptid = psthread_create(async_manager_thread, NULL);
  547.     psthread_add_manager(ptid);
  548. }
  549.  
  550. /** Remove one manager from manager list */
  551. void async_destroy_manager(void)
  552. {
  553.     psthread_remove_manager();
  554. }
  555.  
  556. /** Initialize internal structures needed for async manager */
  557. int _async_init(void)
  558. {
  559.     if (!hash_table_create(&conn_hash_table, CONN_HASH_TABLE_CHAINS, 1, &conn_hash_table_ops)) {
  560.         printf("%s: cannot create hash table\n", "async");
  561.         return ENOMEM;
  562.     }
  563.    
  564. }
  565.  
  566. /** IPC handler for messages in async framework
  567.  *
  568.  * Notify thread that is waiting for this message, that it arrived
  569.  */
  570. static void reply_received(void *private, int retval,
  571.                ipc_call_t *data)
  572. {
  573.     amsg_t *msg = (amsg_t *) private;
  574.  
  575.     msg->retval = retval;
  576.  
  577.     futex_down(&async_futex);
  578.     /* Copy data after futex_down, just in case the
  579.      * call was detached
  580.      */
  581.     if (msg->dataptr)
  582.         *msg->dataptr = *data;
  583.  
  584.     write_barrier();
  585.     /* Remove message from timeout list */
  586.     if (msg->wdata.inlist)
  587.         list_remove(&msg->wdata.link);
  588.     msg->done = 1;
  589.     if (! msg->wdata.active) {
  590.         msg->wdata.active = 1;
  591.         psthread_add_ready(msg->wdata.ptid);
  592.     }
  593.     futex_up(&async_futex);
  594. }
  595.  
  596. /** Send message and return id of the sent message
  597.  *
  598.  * The return value can be used as input for async_wait() to wait
  599.  * for completion.
  600.  */
  601. aid_t async_send_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
  602.            ipc_call_t *dataptr)
  603. {
  604.     amsg_t *msg;
  605.  
  606.     msg = malloc(sizeof(*msg));
  607.     msg->done = 0;
  608.     msg->dataptr = dataptr;
  609.  
  610.     msg->wdata.active = 1; /* We may sleep in next method, but it
  611.                 * will use it's own mechanism */
  612.     ipc_call_async_2(phoneid,method,arg1,arg2,msg,reply_received,1);
  613.  
  614.     return (aid_t) msg;
  615. }
  616.  
  617. /** Wait for a message sent by async framework
  618.  *
  619.  * @param amsgid Message ID to wait for
  620.  * @param retval Pointer to variable where will be stored retval
  621.  *               of the answered message. If NULL, it is ignored.
  622.  *
  623.  */
  624. void async_wait_for(aid_t amsgid, ipcarg_t *retval)
  625. {
  626.     amsg_t *msg = (amsg_t *) amsgid;
  627.     connection_t *conn;
  628.  
  629.     futex_down(&async_futex);
  630.     if (msg->done) {
  631.         futex_up(&async_futex);
  632.         goto done;
  633.     }
  634.  
  635.     msg->wdata.ptid = psthread_get_id();
  636.     msg->wdata.active = 0;
  637.     msg->wdata.inlist = 0;
  638.     /* Leave locked async_futex when entering this function */
  639.     psthread_schedule_next_adv(PS_TO_MANAGER);
  640.     /* futex is up automatically after psthread_schedule_next...*/
  641. done:
  642.     if (retval)
  643.         *retval = msg->retval;
  644.     free(msg);
  645. }
  646.  
  647. /** Wait for a message sent by async framework with timeout
  648.  *
  649.  * @param amsgid Message ID to wait for
  650.  * @param retval Pointer to variable where will be stored retval
  651.  *               of the answered message. If NULL, it is ignored.
  652.  * @param timeout Timeout in usecs
  653.  * @return 0 on success, ETIMEOUT if timeout expired
  654.  *
  655.  */
  656. int async_wait_timeout(aid_t amsgid, ipcarg_t *retval, suseconds_t timeout)
  657. {
  658.     amsg_t *msg = (amsg_t *) amsgid;
  659.     connection_t *conn;
  660.  
  661.     /* TODO: Let it go through the event read at least once */
  662.     if (timeout < 0)
  663.         return ETIMEOUT;
  664.  
  665.     futex_down(&async_futex);
  666.     if (msg->done) {
  667.         futex_up(&async_futex);
  668.         goto done;
  669.     }
  670.  
  671.     gettimeofday(&msg->wdata.expires, NULL);
  672.     tv_add(&msg->wdata.expires, timeout);
  673.  
  674.     msg->wdata.ptid = psthread_get_id();
  675.     msg->wdata.active = 0;
  676.     msg->wdata.inlist = 1;
  677.  
  678.     insert_timeout(&msg->wdata);
  679.  
  680.     /* Leave locked async_futex when entering this function */
  681.     psthread_schedule_next_adv(PS_TO_MANAGER);
  682.     /* futex is up automatically after psthread_schedule_next...*/
  683.  
  684.     if (!msg->done)
  685.         return ETIMEOUT;
  686.  
  687. done:
  688.     if (retval)
  689.         *retval = msg->retval;
  690.     free(msg);
  691.  
  692.     return 0;
  693. }
  694.  
  695. /** Wait specified time, but in the meantime handle incoming events
  696.  *
  697.  * @param timeout Time in microseconds to wait
  698.  */
  699. void async_usleep(suseconds_t timeout)
  700. {
  701.     amsg_t *msg;
  702.    
  703.     msg = malloc(sizeof(*msg));
  704.     if (!msg)
  705.         return;
  706.  
  707.     msg->wdata.ptid = psthread_get_id();
  708.     msg->wdata.inlist = 1;
  709.     msg->wdata.active = 0;
  710.  
  711.     gettimeofday(&msg->wdata.expires, NULL);
  712.     tv_add(&msg->wdata.expires, timeout);
  713.  
  714.     futex_down(&async_futex);
  715.     insert_timeout(&msg->wdata);
  716.     /* Leave locked async_futex when entering this function */
  717.     psthread_schedule_next_adv(PS_TO_MANAGER);
  718.     /* futex is up automatically after psthread_schedule_next...*/
  719.     free(msg);
  720. }
  721.  
  722. /** Set function that is called, IPC_M_CONNECT_ME_TO is received
  723.  *
  724.  * @param conn Function that will form new psthread.
  725.  */
  726. void async_set_client_connection(async_client_conn_t conn)
  727. {
  728.     client_connection = conn;
  729. }
  730.