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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. /** Identifier of incoming connection handled by current thread */
  138. __thread connection_t *PS_connection;
  139. /** If true, it is forbidden to use async_req functions and
  140.  *  all preemption is disabled */
  141. __thread int in_interrupt_handler;
  142.  
  143. static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);
  144. static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call);
  145. static async_client_conn_t client_connection = default_client_connection;
  146. static async_client_conn_t interrupt_received = default_interrupt_received;
  147.  
  148. /** Add microseconds to give timeval */
  149. static void tv_add(struct timeval *tv, suseconds_t usecs)
  150. {
  151.     tv->tv_sec += usecs / 1000000;
  152.     tv->tv_usec += usecs % 1000000;
  153.     if (tv->tv_usec > 1000000) {
  154.         tv->tv_sec++;
  155.         tv->tv_usec -= 1000000;
  156.     }
  157. }
  158.  
  159. /** Subtract 2 timevals, return microseconds difference */
  160. static suseconds_t tv_sub(struct timeval *tv1, struct timeval *tv2)
  161. {
  162.     suseconds_t result;
  163.  
  164.     result = tv1->tv_usec - tv2->tv_usec;
  165.     result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
  166.  
  167.     return result;
  168. }
  169.  
  170. /** Compare timeval
  171.  *
  172.  * @return 1 if tv1 > tv2, otherwise 0
  173.  */
  174. static int tv_gt(struct timeval *tv1, struct timeval *tv2)
  175. {
  176.     if (tv1->tv_sec > tv2->tv_sec)
  177.         return 1;
  178.     if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
  179.         return 1;
  180.     return 0;
  181. }
  182. static int tv_gteq(struct timeval *tv1, struct timeval *tv2)
  183. {
  184.     if (tv1->tv_sec > tv2->tv_sec)
  185.         return 1;
  186.     if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
  187.         return 1;
  188.     return 0;
  189. }
  190.  
  191. /* Hash table functions */
  192. #define CONN_HASH_TABLE_CHAINS  32
  193.  
  194. static hash_index_t conn_hash(unsigned long *key)
  195. {
  196.     assert(key);
  197.     return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
  198. }
  199.  
  200. static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
  201. {
  202.     connection_t *hs;
  203.  
  204.     hs = hash_table_get_instance(item, connection_t, link);
  205.    
  206.     return key[0] == hs->in_phone_hash;
  207. }
  208.  
  209. static void conn_remove(link_t *item)
  210. {
  211.     free(hash_table_get_instance(item, connection_t, link));
  212. }
  213.  
  214.  
  215. /** Operations for NS hash table. */
  216. static hash_table_operations_t conn_hash_table_ops = {
  217.     .hash = conn_hash,
  218.     .compare = conn_compare,
  219.     .remove_callback = conn_remove
  220. };
  221.  
  222. /** Insert sort timeout msg into timeouts list
  223.  *
  224.  */
  225. static void insert_timeout(awaiter_t *wd)
  226. {
  227.     link_t *tmp;
  228.     awaiter_t *cur;
  229.  
  230.     wd->timedout = 0;
  231.     wd->inlist = 1;
  232.  
  233.     tmp = timeout_list.next;
  234.     while (tmp != &timeout_list) {
  235.         cur = list_get_instance(tmp, awaiter_t, link);
  236.         if (tv_gteq(&cur->expires, &wd->expires))
  237.             break;
  238.         tmp = tmp->next;
  239.     }
  240.     list_append(&wd->link, tmp);
  241. }
  242.  
  243. /*************************************************/
  244.  
  245. /** Try to route a call to an appropriate connection thread
  246.  *
  247.  */
  248. static int route_call(ipc_callid_t callid, ipc_call_t *call)
  249. {
  250.     connection_t *conn;
  251.     msg_t *msg;
  252.     link_t *hlp;
  253.     unsigned long key;
  254.  
  255.     futex_down(&async_futex);
  256.  
  257.     key = call->in_phone_hash;
  258.     hlp = hash_table_find(&conn_hash_table, &key);
  259.     if (!hlp) {
  260.         futex_up(&async_futex);
  261.         return 0;
  262.     }
  263.     conn = hash_table_get_instance(hlp, connection_t, link);
  264.  
  265.     msg = malloc(sizeof(*msg));
  266.     msg->callid = callid;
  267.     msg->call = *call;
  268.     list_append(&msg->link, &conn->msg_queue);
  269.    
  270.     /* If the call is waiting for event, run it */
  271.     if (!conn->wdata.active) {
  272.         /* If in timeout list, remove it */
  273.         if (conn->wdata.inlist) {
  274.             conn->wdata.inlist = 0;
  275.             list_remove(&conn->wdata.link);
  276.         }
  277.         conn->wdata.active = 1;
  278.         psthread_add_ready(conn->wdata.ptid);
  279.     }
  280.  
  281.     futex_up(&async_futex);
  282.  
  283.     return 1;
  284. }
  285.  
  286. /** Return new incoming message for current(thread-local) connection */
  287. ipc_callid_t async_get_call_timeout(ipc_call_t *call, suseconds_t usecs)
  288. {
  289.     msg_t *msg;
  290.     ipc_callid_t callid;
  291.     connection_t *conn;
  292.    
  293.     assert(PS_connection);
  294.     /* GCC 4.1.0 coughs on PS_connection-> dereference,
  295.      * GCC 4.1.1 happilly puts the rdhwr instruction in delay slot.
  296.      *           I would never expect to find so many errors in
  297.      *           compiler *($&$(*&$
  298.      */
  299.     conn = PS_connection;
  300.  
  301.     futex_down(&async_futex);
  302.  
  303.     if (usecs) {
  304.         gettimeofday(&conn->wdata.expires, NULL);
  305.         tv_add(&conn->wdata.expires, usecs);
  306.     } else {
  307.         conn->wdata.inlist = 0;
  308.     }
  309.     /* If nothing in queue, wait until something appears */
  310.     while (list_empty(&conn->msg_queue)) {
  311.         if (usecs)
  312.             insert_timeout(&conn->wdata);
  313.  
  314.         conn->wdata.active = 0;
  315.         psthread_schedule_next_adv(PS_TO_MANAGER);
  316.         /* Futex is up after getting back from async_manager
  317.          * get it again */
  318.         futex_down(&async_futex);
  319.         if (usecs && conn->wdata.timedout && \
  320.             list_empty(&conn->msg_queue)) {
  321.             /* If we timed out-> exit */
  322.             futex_up(&async_futex);
  323.             return 0;
  324.         }
  325.     }
  326.    
  327.     msg = list_get_instance(conn->msg_queue.next, msg_t, link);
  328.     list_remove(&msg->link);
  329.     callid = msg->callid;
  330.     *call = msg->call;
  331.     free(msg);
  332.    
  333.     futex_up(&async_futex);
  334.     return callid;
  335. }
  336.  
  337. /** Thread function that gets created on new connection
  338.  *
  339.  * This function is defined as a weak symbol - to be redefined in
  340.  * user code.
  341.  */
  342. static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
  343. {
  344.     ipc_answer_fast(callid, ENOENT, 0, 0);
  345. }
  346. static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call)
  347. {
  348. }
  349.  
  350. /** Wrapper for client connection thread
  351.  *
  352.  * When new connection arrives, thread with this function is created.
  353.  * It calls client_connection and does final cleanup.
  354.  *
  355.  * @parameter arg Connection structure pointer
  356.  */
  357. static int connection_thread(void  *arg)
  358. {
  359.     unsigned long key;
  360.     msg_t *msg;
  361.  
  362.     /* Setup thread local connection pointer */
  363.     PS_connection = (connection_t *)arg;
  364.     PS_connection->cthread(PS_connection->callid, &PS_connection->call);
  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.         in_interrupt_handler = 1;
  438.         (*interrupt_received)(callid,call);
  439.         in_interrupt_handler = 0;
  440.         return;
  441.     case IPC_M_CONNECT_ME_TO:
  442.         /* Open new connection with thread etc. */
  443.         async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
  444.         return;
  445.     }
  446.  
  447.     /* Try to route call through connection tables */
  448.     if (route_call(callid, call))
  449.         return;
  450.  
  451.     /* Unknown call from unknown phone - hang it up */
  452.     ipc_answer_fast(callid, EHANGUP, 0, 0);
  453. }
  454.  
  455. /** Fire all timeouts that expired
  456.  *
  457.  */
  458. static void handle_expired_timeouts(void)
  459. {
  460.     struct timeval tv;
  461.     awaiter_t *waiter;
  462.     link_t *cur;
  463.  
  464.     gettimeofday(&tv,NULL);
  465.     futex_down(&async_futex);
  466.  
  467.     cur = timeout_list.next;
  468.     while (cur != &timeout_list) {
  469.         waiter = list_get_instance(cur,awaiter_t,link);
  470.         if (tv_gt(&waiter->expires, &tv))
  471.             break;
  472.         cur = cur->next;
  473.         list_remove(&waiter->link);
  474.         waiter->inlist = 0;
  475.         waiter->timedout = 1;
  476.         /* Redundant condition? The thread should not
  477.          * be active when it gets here.
  478.          */
  479.         if (!waiter->active) {
  480.             waiter->active = 1;
  481.             psthread_add_ready(waiter->ptid);
  482.         }
  483.     }
  484.  
  485.     futex_up(&async_futex);
  486. }
  487.  
  488. /** Endless loop dispatching incoming calls and answers */
  489. static int async_manager_worker(void)
  490. {
  491.     ipc_call_t call;
  492.     ipc_callid_t callid;
  493.     int timeout;
  494.     awaiter_t *waiter;
  495.     struct timeval tv;
  496.  
  497.     while (1) {
  498.         if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
  499.             futex_up(&async_futex); /* async_futex is always held
  500.                         * when entering manager thread
  501.                         */
  502.             continue;
  503.         }
  504.         futex_down(&async_futex);
  505.         if (!list_empty(&timeout_list)) {
  506.             waiter = list_get_instance(timeout_list.next,awaiter_t,link);
  507.             gettimeofday(&tv,NULL);
  508.             if (tv_gteq(&tv, &waiter->expires)) {
  509.                 futex_up(&async_futex);
  510.                 handle_expired_timeouts();
  511.                 continue;
  512.             } else
  513.                 timeout = tv_sub(&waiter->expires, &tv);
  514.         } else
  515.             timeout = SYNCH_NO_TIMEOUT;
  516.         futex_up(&async_futex);
  517.  
  518.         callid = ipc_wait_cycle(&call, timeout, SYNCH_FLAGS_NONE);
  519.  
  520.         if (!callid) {
  521.             handle_expired_timeouts();
  522.             continue;
  523.         }
  524.  
  525.         if (callid & IPC_CALLID_ANSWERED) {
  526.             continue;
  527.         }
  528.  
  529.         handle_call(callid, &call);
  530.     }
  531. }
  532.  
  533. /** Function to start async_manager as a standalone thread
  534.  *
  535.  * When more kernel threads are used, one async manager should
  536.  * exist per thread. The particular implementation may change,
  537.  * currently one async_manager is started automatically per kernel
  538.  * thread except main thread.
  539.  */
  540. static int async_manager_thread(void *arg)
  541. {
  542.     futex_up(&async_futex); /* async_futex is always locked when entering
  543.                 * manager */
  544.     async_manager_worker();
  545. }
  546.  
  547. /** Add one manager to manager list */
  548. void async_create_manager(void)
  549. {
  550.     pstid_t ptid;
  551.  
  552.     ptid = psthread_create(async_manager_thread, NULL);
  553.     psthread_add_manager(ptid);
  554. }
  555.  
  556. /** Remove one manager from manager list */
  557. void async_destroy_manager(void)
  558. {
  559.     psthread_remove_manager();
  560. }
  561.  
  562. /** Initialize internal structures needed for async manager */
  563. int _async_init(void)
  564. {
  565.     if (!hash_table_create(&conn_hash_table, CONN_HASH_TABLE_CHAINS, 1, &conn_hash_table_ops)) {
  566.         printf("%s: cannot create hash table\n", "async");
  567.         return ENOMEM;
  568.     }
  569.    
  570. }
  571.  
  572. /** IPC handler for messages in async framework
  573.  *
  574.  * Notify thread that is waiting for this message, that it arrived
  575.  */
  576. static void reply_received(void *private, int retval,
  577.                ipc_call_t *data)
  578. {
  579.     amsg_t *msg = (amsg_t *) private;
  580.  
  581.     msg->retval = retval;
  582.  
  583.     futex_down(&async_futex);
  584.     /* Copy data after futex_down, just in case the
  585.      * call was detached
  586.      */
  587.     if (msg->dataptr)
  588.         *msg->dataptr = *data;
  589.  
  590.     write_barrier();
  591.     /* Remove message from timeout list */
  592.     if (msg->wdata.inlist)
  593.         list_remove(&msg->wdata.link);
  594.     msg->done = 1;
  595.     if (! msg->wdata.active) {
  596.         msg->wdata.active = 1;
  597.         psthread_add_ready(msg->wdata.ptid);
  598.     }
  599.     futex_up(&async_futex);
  600. }
  601.  
  602. /** Send message and return id of the sent message
  603.  *
  604.  * The return value can be used as input for async_wait() to wait
  605.  * for completion.
  606.  */
  607. aid_t async_send_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
  608.            ipc_call_t *dataptr)
  609. {
  610.     amsg_t *msg;
  611.  
  612.     if (in_interrupt_handler) {
  613.         printf("Cannot send asynchronou request in interrupt handler.\n");
  614.         _exit(1);
  615.     }
  616.  
  617.     msg = malloc(sizeof(*msg));
  618.     msg->done = 0;
  619.     msg->dataptr = dataptr;
  620.  
  621.     msg->wdata.active = 1; /* We may sleep in next method, but it
  622.                 * will use it's own mechanism */
  623.     ipc_call_async_2(phoneid,method,arg1,arg2,msg,reply_received,1);
  624.  
  625.     return (aid_t) msg;
  626. }
  627.  
  628. /** Send message and return id of the sent message
  629.  *
  630.  * The return value can be used as input for async_wait() to wait
  631.  * for completion.
  632.  */
  633. aid_t async_send_3(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
  634.            ipcarg_t arg3, ipc_call_t *dataptr)
  635. {
  636.     amsg_t *msg;
  637.  
  638.     if (in_interrupt_handler) {
  639.         printf("Cannot send asynchronou request in interrupt handler.\n");
  640.         _exit(1);
  641.     }
  642.  
  643.     msg = malloc(sizeof(*msg));
  644.     msg->done = 0;
  645.     msg->dataptr = dataptr;
  646.  
  647.     msg->wdata.active = 1; /* We may sleep in next method, but it
  648.                 * will use it's own mechanism */
  649.     ipc_call_async_3(phoneid,method,arg1,arg2,arg3, msg,reply_received,1);
  650.  
  651.     return (aid_t) msg;
  652. }
  653.  
  654. /** Wait for a message sent by async framework
  655.  *
  656.  * @param amsgid Message ID to wait for
  657.  * @param retval Pointer to variable where will be stored retval
  658.  *               of the answered message. If NULL, it is ignored.
  659.  *
  660.  */
  661. void async_wait_for(aid_t amsgid, ipcarg_t *retval)
  662. {
  663.     amsg_t *msg = (amsg_t *) amsgid;
  664.     connection_t *conn;
  665.  
  666.     futex_down(&async_futex);
  667.     if (msg->done) {
  668.         futex_up(&async_futex);
  669.         goto done;
  670.     }
  671.  
  672.     msg->wdata.ptid = psthread_get_id();
  673.     msg->wdata.active = 0;
  674.     msg->wdata.inlist = 0;
  675.     /* Leave locked async_futex when entering this function */
  676.     psthread_schedule_next_adv(PS_TO_MANAGER);
  677.     /* futex is up automatically after psthread_schedule_next...*/
  678. done:
  679.     if (retval)
  680.         *retval = msg->retval;
  681.     free(msg);
  682. }
  683.  
  684. /** Wait for a message sent by async framework with timeout
  685.  *
  686.  * @param amsgid Message ID to wait for
  687.  * @param retval Pointer to variable where will be stored retval
  688.  *               of the answered message. If NULL, it is ignored.
  689.  * @param timeout Timeout in usecs
  690.  * @return 0 on success, ETIMEOUT if timeout expired
  691.  *
  692.  */
  693. int async_wait_timeout(aid_t amsgid, ipcarg_t *retval, suseconds_t timeout)
  694. {
  695.     amsg_t *msg = (amsg_t *) amsgid;
  696.     connection_t *conn;
  697.  
  698.     /* TODO: Let it go through the event read at least once */
  699.     if (timeout < 0)
  700.         return ETIMEOUT;
  701.  
  702.     futex_down(&async_futex);
  703.     if (msg->done) {
  704.         futex_up(&async_futex);
  705.         goto done;
  706.     }
  707.  
  708.     gettimeofday(&msg->wdata.expires, NULL);
  709.     tv_add(&msg->wdata.expires, timeout);
  710.  
  711.     msg->wdata.ptid = psthread_get_id();
  712.     msg->wdata.active = 0;
  713.     insert_timeout(&msg->wdata);
  714.  
  715.     /* Leave locked async_futex when entering this function */
  716.     psthread_schedule_next_adv(PS_TO_MANAGER);
  717.     /* futex is up automatically after psthread_schedule_next...*/
  718.  
  719.     if (!msg->done)
  720.         return ETIMEOUT;
  721.  
  722. done:
  723.     if (retval)
  724.         *retval = msg->retval;
  725.     free(msg);
  726.  
  727.     return 0;
  728. }
  729.  
  730. /** Wait specified time, but in the meantime handle incoming events
  731.  *
  732.  * @param timeout Time in microseconds to wait
  733.  */
  734. void async_usleep(suseconds_t timeout)
  735. {
  736.     amsg_t *msg;
  737.    
  738.     if (in_interrupt_handler) {
  739.         printf("Cannot call async_usleep in interrupt handler.\n");
  740.         _exit(1);
  741.     }
  742.  
  743.     msg = malloc(sizeof(*msg));
  744.     if (!msg)
  745.         return;
  746.  
  747.     msg->wdata.ptid = psthread_get_id();
  748.     msg->wdata.active = 0;
  749.  
  750.     gettimeofday(&msg->wdata.expires, NULL);
  751.     tv_add(&msg->wdata.expires, timeout);
  752.  
  753.     futex_down(&async_futex);
  754.     insert_timeout(&msg->wdata);
  755.     /* Leave locked async_futex when entering this function */
  756.     psthread_schedule_next_adv(PS_TO_MANAGER);
  757.     /* futex is up automatically after psthread_schedule_next...*/
  758.     free(msg);
  759. }
  760.  
  761. /** Set function that is called, IPC_M_CONNECT_ME_TO is received
  762.  *
  763.  * @param conn Function that will form new psthread.
  764.  */
  765. void async_set_client_connection(async_client_conn_t conn)
  766. {
  767.     client_connection = conn;
  768. }
  769. void async_set_interrupt_received(async_client_conn_t conn)
  770. {
  771.     interrupt_received = conn;
  772. }
  773.  
  774. /* Primitive functions for simple communication */
  775. void async_msg_3(int phoneid, ipcarg_t method, ipcarg_t arg1,
  776.          ipcarg_t arg2, ipcarg_t arg3)
  777. {
  778.     ipc_call_async_3(phoneid, method, arg1, arg2, arg3, NULL, NULL, !in_interrupt_handler);
  779. }
  780.  
  781. void async_msg_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2)
  782. {
  783.     ipc_call_async_2(phoneid, method, arg1, arg2, NULL, NULL, !in_interrupt_handler);
  784. }
  785.