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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. /** @addtogroup libc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. /**
  36.  * Asynchronous library
  37.  *
  38.  * The aim of this library is facilitating writing programs utilizing
  39.  * the asynchronous nature of Helenos IPC, yet using a normal way
  40.  * of programming.
  41.  *
  42.  * You should be able to write very simple multithreaded programs,
  43.  * the async framework will automatically take care of most synchronization
  44.  * problems.
  45.  *
  46.  * Default semantics:
  47.  * - send() - send asynchronously. If the kernel refuses to send more
  48.  *            messages, [ try to get responses from kernel, if nothing
  49.  *            found, might try synchronous ]
  50.  *
  51.  * Example of use:
  52.  *
  53.  * 1) Multithreaded client application
  54.  *  create_thread(thread1);
  55.  *  create_thread(thread2);
  56.  *  ...
  57.  *  
  58.  *  thread1() {
  59.  *        conn = ipc_connect_me_to();
  60.  *        c1 = send(conn);
  61.  *        c2 = send(conn);
  62.  *        wait_for(c1);
  63.  *        wait_for(c2);
  64.  *  }
  65.  *
  66.  *
  67.  * 2) Multithreaded server application
  68.  * main() {
  69.  *      async_manager();
  70.  * }
  71.  *
  72.  *
  73.  * client_connection(icallid, *icall) {
  74.  *       if (want_refuse) {
  75.  *           ipc_answer_fast(icallid, ELIMIT, 0, 0);
  76.  *           return;
  77.  *       }
  78.  *       ipc_answer_fast(icallid, 0, 0, 0);
  79.  *
  80.  *       callid = async_get_call(&call);
  81.  *       handle(callid, call);
  82.  *       ipc_answer_fast(callid, 1,2,3);
  83.  *
  84.  *       callid = async_get_call(&call);
  85.  *       ....
  86.  * }
  87.  *
  88.  * TODO: Detaching/joining dead psthreads?
  89.  */
  90. #include <futex.h>
  91. #include <async.h>
  92. #include <psthread.h>
  93. #include <stdio.h>
  94. #include <libadt/hash_table.h>
  95. #include <libadt/list.h>
  96. #include <ipc/ipc.h>
  97. #include <assert.h>
  98. #include <errno.h>
  99. #include <time.h>
  100. #include <arch/barrier.h>
  101.  
  102. atomic_t async_futex = FUTEX_INITIALIZER;
  103. static hash_table_t conn_hash_table;
  104. static LIST_INITIALIZE(timeout_list);
  105.  
  106. typedef struct {
  107.     struct timeval expires;      /**< Expiration time for waiting thread */
  108.     int inlist;             /**< If true, this struct is in timeout list */
  109.     link_t link;
  110.  
  111.     pstid_t ptid;                /**< Thread waiting for this message */
  112.     int active;                  /**< If this thread is currently active */
  113.     int timedout;                /**< If true, we timed out */
  114. } awaiter_t;
  115.  
  116. typedef struct {
  117.     awaiter_t wdata;
  118.  
  119.     int done;                    /**< If reply was received */
  120.     ipc_call_t *dataptr;         /**< Pointer where the answer data
  121.                       *   is stored */
  122.     ipcarg_t retval;
  123. } amsg_t;
  124.  
  125. typedef struct {
  126.     link_t link;
  127.     ipc_callid_t callid;
  128.     ipc_call_t call;
  129. } msg_t;
  130.  
  131. typedef struct {
  132.     awaiter_t wdata;
  133.  
  134.     link_t link;             /**< Hash table link */
  135.     ipcarg_t in_phone_hash;  /**< Incoming phone hash. */
  136.     link_t msg_queue;        /**< Messages that should be delivered to this thread */
  137.     /* Structures for connection opening packet */
  138.     ipc_callid_t callid;
  139.     ipc_call_t call;
  140.     ipc_callid_t close_callid; /* Identification of closing packet */
  141.     void (*cthread)(ipc_callid_t,ipc_call_t *);
  142. } connection_t;
  143.  
  144. /** Identifier of incoming connection handled by current thread */
  145. __thread connection_t *PS_connection;
  146. /** If true, it is forbidden to use async_req functions and
  147.  *  all preemption is disabled */
  148. __thread int in_interrupt_handler;
  149.  
  150. static void default_client_connection(ipc_callid_t callid, ipc_call_t *call);
  151. static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call);
  152. static async_client_conn_t client_connection = default_client_connection;
  153. static async_client_conn_t interrupt_received = default_interrupt_received;
  154.  
  155. /** Add microseconds to give timeval */
  156. static void tv_add(struct timeval *tv, suseconds_t usecs)
  157. {
  158.     tv->tv_sec += usecs / 1000000;
  159.     tv->tv_usec += usecs % 1000000;
  160.     if (tv->tv_usec > 1000000) {
  161.         tv->tv_sec++;
  162.         tv->tv_usec -= 1000000;
  163.     }
  164. }
  165.  
  166. /** Subtract 2 timevals, return microseconds difference */
  167. static suseconds_t tv_sub(struct timeval *tv1, struct timeval *tv2)
  168. {
  169.     suseconds_t result;
  170.  
  171.     result = tv1->tv_usec - tv2->tv_usec;
  172.     result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
  173.  
  174.     return result;
  175. }
  176.  
  177. /** Compare timeval
  178.  *
  179.  * @return 1 if tv1 > tv2, otherwise 0
  180.  */
  181. static int tv_gt(struct timeval *tv1, struct timeval *tv2)
  182. {
  183.     if (tv1->tv_sec > tv2->tv_sec)
  184.         return 1;
  185.     if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
  186.         return 1;
  187.     return 0;
  188. }
  189. static int tv_gteq(struct timeval *tv1, struct timeval *tv2)
  190. {
  191.     if (tv1->tv_sec > tv2->tv_sec)
  192.         return 1;
  193.     if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
  194.         return 1;
  195.     return 0;
  196. }
  197.  
  198. /* Hash table functions */
  199. #define CONN_HASH_TABLE_CHAINS  32
  200.  
  201. static hash_index_t conn_hash(unsigned long *key)
  202. {
  203.     assert(key);
  204.     return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
  205. }
  206.  
  207. static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
  208. {
  209.     connection_t *hs;
  210.  
  211.     hs = hash_table_get_instance(item, connection_t, link);
  212.    
  213.     return key[0] == hs->in_phone_hash;
  214. }
  215.  
  216. static void conn_remove(link_t *item)
  217. {
  218.     free(hash_table_get_instance(item, connection_t, link));
  219. }
  220.  
  221.  
  222. /** Operations for NS hash table. */
  223. static hash_table_operations_t conn_hash_table_ops = {
  224.     .hash = conn_hash,
  225.     .compare = conn_compare,
  226.     .remove_callback = conn_remove
  227. };
  228.  
  229. /** Insert sort timeout msg into timeouts list
  230.  *
  231.  */
  232. static void insert_timeout(awaiter_t *wd)
  233. {
  234.     link_t *tmp;
  235.     awaiter_t *cur;
  236.  
  237.     wd->timedout = 0;
  238.     wd->inlist = 1;
  239.  
  240.     tmp = timeout_list.next;
  241.     while (tmp != &timeout_list) {
  242.         cur = list_get_instance(tmp, awaiter_t, link);
  243.         if (tv_gteq(&cur->expires, &wd->expires))
  244.             break;
  245.         tmp = tmp->next;
  246.     }
  247.     list_append(&wd->link, tmp);
  248. }
  249.  
  250. /*************************************************/
  251.  
  252. /** Try to route a call to an appropriate connection thread
  253.  *
  254.  */
  255. static int route_call(ipc_callid_t callid, ipc_call_t *call)
  256. {
  257.     connection_t *conn;
  258.     msg_t *msg;
  259.     link_t *hlp;
  260.     unsigned long key;
  261.  
  262.     futex_down(&async_futex);
  263.  
  264.     key = call->in_phone_hash;
  265.     hlp = hash_table_find(&conn_hash_table, &key);
  266.     if (!hlp) {
  267.         futex_up(&async_futex);
  268.         return 0;
  269.     }
  270.     conn = hash_table_get_instance(hlp, connection_t, link);
  271.  
  272.     msg = malloc(sizeof(*msg));
  273.     msg->callid = callid;
  274.     msg->call = *call;
  275.     list_append(&msg->link, &conn->msg_queue);
  276.  
  277.     if (IPC_GET_METHOD(*call) == IPC_M_PHONE_HUNGUP)
  278.         conn->close_callid = callid;
  279.    
  280.     /* If the call is waiting for event, run it */
  281.     if (!conn->wdata.active) {
  282.         /* If in timeout list, remove it */
  283.         if (conn->wdata.inlist) {
  284.             conn->wdata.inlist = 0;
  285.             list_remove(&conn->wdata.link);
  286.         }
  287.         conn->wdata.active = 1;
  288.         psthread_add_ready(conn->wdata.ptid);
  289.     }
  290.  
  291.     futex_up(&async_futex);
  292.  
  293.     return 1;
  294. }
  295.  
  296. /** Return new incoming message for current(thread-local) connection */
  297. ipc_callid_t async_get_call_timeout(ipc_call_t *call, suseconds_t usecs)
  298. {
  299.     msg_t *msg;
  300.     ipc_callid_t callid;
  301.     connection_t *conn;
  302.    
  303.     assert(PS_connection);
  304.     /* GCC 4.1.0 coughs on PS_connection-> dereference,
  305.      * GCC 4.1.1 happilly puts the rdhwr instruction in delay slot.
  306.      *           I would never expect to find so many errors in
  307.      *           compiler *($&$(*&$
  308.      */
  309.     conn = PS_connection;
  310.  
  311.     futex_down(&async_futex);
  312.  
  313.     if (usecs) {
  314.         gettimeofday(&conn->wdata.expires, NULL);
  315.         tv_add(&conn->wdata.expires, usecs);
  316.     } else {
  317.         conn->wdata.inlist = 0;
  318.     }
  319.     /* If nothing in queue, wait until something appears */
  320.     while (list_empty(&conn->msg_queue)) {
  321.         if (usecs)
  322.             insert_timeout(&conn->wdata);
  323.  
  324.         conn->wdata.active = 0;
  325.         psthread_schedule_next_adv(PS_TO_MANAGER);
  326.         /* Futex is up after getting back from async_manager
  327.          * get it again */
  328.         futex_down(&async_futex);
  329.         if (usecs && conn->wdata.timedout && \
  330.             list_empty(&conn->msg_queue)) {
  331.             /* If we timed out-> exit */
  332.             futex_up(&async_futex);
  333.             return 0;
  334.         }
  335.     }
  336.    
  337.     msg = list_get_instance(conn->msg_queue.next, msg_t, link);
  338.     list_remove(&msg->link);
  339.     callid = msg->callid;
  340.     *call = msg->call;
  341.     free(msg);
  342.    
  343.     futex_up(&async_futex);
  344.     return callid;
  345. }
  346.  
  347. /** Thread function that gets created on new connection
  348.  *
  349.  * This function is defined as a weak symbol - to be redefined in
  350.  * user code.
  351.  */
  352. static void default_client_connection(ipc_callid_t callid, ipc_call_t *call)
  353. {
  354.     ipc_answer_fast(callid, ENOENT, 0, 0);
  355. }
  356. static void default_interrupt_received(ipc_callid_t callid, ipc_call_t *call)
  357. {
  358. }
  359.  
  360. /** Wrapper for client connection thread
  361.  *
  362.  * When new connection arrives, thread with this function is created.
  363.  * It calls client_connection and does final cleanup.
  364.  *
  365.  * @param arg Connection structure pointer
  366.  */
  367. static int connection_thread(void  *arg)
  368. {
  369.     unsigned long key;
  370.     msg_t *msg;
  371.     int close_answered = 0;
  372.  
  373.     /* Setup thread local connection pointer */
  374.     PS_connection = (connection_t *)arg;
  375.     PS_connection->cthread(PS_connection->callid, &PS_connection->call);
  376.    
  377.     /* Remove myself from connection hash table */
  378.     futex_down(&async_futex);
  379.     key = PS_connection->in_phone_hash;
  380.     hash_table_remove(&conn_hash_table, &key, 1);
  381.     futex_up(&async_futex);
  382.    
  383.     /* Answer all remaining messages with ehangup */
  384.     while (!list_empty(&PS_connection->msg_queue)) {
  385.         msg = list_get_instance(PS_connection->msg_queue.next, msg_t, link);
  386.         list_remove(&msg->link);
  387.         if (msg->callid == PS_connection->close_callid)
  388.             close_answered = 1;
  389.         ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
  390.         free(msg);
  391.     }
  392.     if (PS_connection->close_callid)
  393.         ipc_answer_fast(PS_connection->close_callid, 0, 0, 0);
  394.    
  395.     return 0;
  396. }
  397.  
  398. /** Create new thread for a new connection
  399.  *
  400.  * Creates new thread for connection, fills in connection
  401.  * structures and inserts it into the hash table, so that
  402.  * later we can easily do routing of messages to particular
  403.  * threads.
  404.  *
  405.  * @param in_phone_hash Identification of the incoming connection
  406.  * @param callid Callid of the IPC_M_CONNECT_ME_TO packet
  407.  * @param call Call data of the opening packet
  408.  * @param cthread Thread function that should be called upon
  409.  *                opening the connection
  410.  * @return New thread id
  411.  */
  412. 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 *))
  413. {
  414.     connection_t *conn;
  415.     unsigned long key;
  416.  
  417.     conn = malloc(sizeof(*conn));
  418.     if (!conn) {
  419.         ipc_answer_fast(callid, ENOMEM, 0, 0);
  420.         return NULL;
  421.     }
  422.     conn->in_phone_hash = in_phone_hash;
  423.     list_initialize(&conn->msg_queue);
  424.     conn->callid = callid;
  425.     conn->close_callid = 0;
  426.     if (call)
  427.         conn->call = *call;
  428.     conn->wdata.active = 1; /* We will activate it asap */
  429.     conn->cthread = cthread;
  430.  
  431.     conn->wdata.ptid = psthread_create(connection_thread, conn);
  432.     if (!conn->wdata.ptid) {
  433.         free(conn);
  434.         ipc_answer_fast(callid, ENOMEM, 0, 0);
  435.         return NULL;
  436.     }
  437.     /* Add connection to hash table */
  438.     key = conn->in_phone_hash;
  439.     futex_down(&async_futex);
  440.     hash_table_insert(&conn_hash_table, &key, &conn->link);
  441.     futex_up(&async_futex);
  442.  
  443.     psthread_add_ready(conn->wdata.ptid);
  444.  
  445.     return conn->wdata.ptid;
  446. }
  447.  
  448. /** Handle call that was received */
  449. static void handle_call(ipc_callid_t callid, ipc_call_t *call)
  450. {
  451.     /* Unrouted call - do some default behaviour */
  452.     if ((callid & IPC_CALLID_NOTIFICATION)) {
  453.         in_interrupt_handler = 1;
  454.         (*interrupt_received)(callid,call);
  455.         in_interrupt_handler = 0;
  456.         return;
  457.     }      
  458.  
  459.     switch (IPC_GET_METHOD(*call)) {
  460.     case IPC_M_CONNECT_ME_TO:
  461.         /* Open new connection with thread etc. */
  462.         async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
  463.         return;
  464.     }
  465.  
  466.     /* Try to route call through connection tables */
  467.     if (route_call(callid, call))
  468.         return;
  469.  
  470.     /* Unknown call from unknown phone - hang it up */
  471.     ipc_answer_fast(callid, EHANGUP, 0, 0);
  472. }
  473.  
  474. /** Fire all timeouts that expired
  475.  *
  476.  */
  477. static void handle_expired_timeouts(void)
  478. {
  479.     struct timeval tv;
  480.     awaiter_t *waiter;
  481.     link_t *cur;
  482.  
  483.     gettimeofday(&tv,NULL);
  484.     futex_down(&async_futex);
  485.  
  486.     cur = timeout_list.next;
  487.     while (cur != &timeout_list) {
  488.         waiter = list_get_instance(cur,awaiter_t,link);
  489.         if (tv_gt(&waiter->expires, &tv))
  490.             break;
  491.         cur = cur->next;
  492.         list_remove(&waiter->link);
  493.         waiter->inlist = 0;
  494.         waiter->timedout = 1;
  495.         /* Redundant condition? The thread should not
  496.          * be active when it gets here.
  497.          */
  498.         if (!waiter->active) {
  499.             waiter->active = 1;
  500.             psthread_add_ready(waiter->ptid);
  501.         }
  502.     }
  503.  
  504.     futex_up(&async_futex);
  505. }
  506.  
  507. /** Endless loop dispatching incoming calls and answers */
  508. static int async_manager_worker(void)
  509. {
  510.     ipc_call_t call;
  511.     ipc_callid_t callid;
  512.     int timeout;
  513.     awaiter_t *waiter;
  514.     struct timeval tv;
  515.  
  516.     while (1) {
  517.         if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
  518.             futex_up(&async_futex);
  519.             /* async_futex is always held
  520.              * when entering manager thread
  521.              */
  522.             continue;
  523.         }
  524.         futex_down(&async_futex);
  525.         if (!list_empty(&timeout_list)) {
  526.             waiter = list_get_instance(timeout_list.next,awaiter_t,link);
  527.             gettimeofday(&tv,NULL);
  528.             if (tv_gteq(&tv, &waiter->expires)) {
  529.                 futex_up(&async_futex);
  530.                 handle_expired_timeouts();
  531.                 continue;
  532.             } else
  533.                 timeout = tv_sub(&waiter->expires, &tv);
  534.         } else
  535.             timeout = SYNCH_NO_TIMEOUT;
  536.         futex_up(&async_futex);
  537.  
  538.         callid = ipc_wait_cycle(&call, timeout, SYNCH_FLAGS_NONE);
  539.  
  540.         if (!callid) {
  541.             handle_expired_timeouts();
  542.             continue;
  543.         }
  544.  
  545.         if (callid & IPC_CALLID_ANSWERED) {
  546.             continue;
  547.         }
  548.  
  549.         handle_call(callid, &call);
  550.     }
  551.    
  552.     return 0;
  553. }
  554.  
  555. /** Function to start async_manager as a standalone thread
  556.  *
  557.  * When more kernel threads are used, one async manager should
  558.  * exist per thread. The particular implementation may change,
  559.  * currently one async_manager is started automatically per kernel
  560.  * thread except main thread.
  561.  */
  562. static int async_manager_thread(void *arg)
  563. {
  564.     futex_up(&async_futex);
  565.     /* async_futex is always locked when entering
  566.      * manager */
  567.     async_manager_worker();
  568.    
  569.     return 0;
  570. }
  571.  
  572. /** Add one manager to manager list */
  573. void async_create_manager(void)
  574. {
  575.     pstid_t ptid;
  576.  
  577.     ptid = psthread_create(async_manager_thread, NULL);
  578.     psthread_add_manager(ptid);
  579. }
  580.  
  581. /** Remove one manager from manager list */
  582. void async_destroy_manager(void)
  583. {
  584.     psthread_remove_manager();
  585. }
  586.  
  587. /** Initialize internal structures needed for async manager */
  588. int _async_init(void)
  589. {
  590.     if (!hash_table_create(&conn_hash_table, CONN_HASH_TABLE_CHAINS, 1, &conn_hash_table_ops)) {
  591.         printf("%s: cannot create hash table\n", "async");
  592.         return ENOMEM;
  593.     }
  594.    
  595.     return 0;
  596. }
  597.  
  598. /** IPC handler for messages in async framework
  599.  *
  600.  * Notify thread that is waiting for this message, that it arrived
  601.  */
  602. static void reply_received(void *private, int retval,
  603.                ipc_call_t *data)
  604. {
  605.     amsg_t *msg = (amsg_t *) private;
  606.  
  607.     msg->retval = retval;
  608.  
  609.     futex_down(&async_futex);
  610.     /* Copy data after futex_down, just in case the
  611.      * call was detached
  612.      */
  613.     if (msg->dataptr)
  614.         *msg->dataptr = *data;
  615.  
  616.     write_barrier();
  617.     /* Remove message from timeout list */
  618.     if (msg->wdata.inlist)
  619.         list_remove(&msg->wdata.link);
  620.     msg->done = 1;
  621.     if (! msg->wdata.active) {
  622.         msg->wdata.active = 1;
  623.         psthread_add_ready(msg->wdata.ptid);
  624.     }
  625.     futex_up(&async_futex);
  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_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
  634.            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_2(phoneid,method,arg1,arg2,msg,reply_received,1);
  650.  
  651.     return (aid_t) msg;
  652. }
  653.  
  654. /** Send message and return id of the sent message
  655.  *
  656.  * The return value can be used as input for async_wait() to wait
  657.  * for completion.
  658.  */
  659. aid_t async_send_3(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
  660.            ipcarg_t arg3, ipc_call_t *dataptr)
  661. {
  662.     amsg_t *msg;
  663.  
  664.     if (in_interrupt_handler) {
  665.         printf("Cannot send asynchronou request in interrupt handler.\n");
  666.         _exit(1);
  667.     }
  668.  
  669.     msg = malloc(sizeof(*msg));
  670.     msg->done = 0;
  671.     msg->dataptr = dataptr;
  672.  
  673.     msg->wdata.active = 1; /* We may sleep in next method, but it
  674.                 * will use it's own mechanism */
  675.     ipc_call_async_3(phoneid,method,arg1,arg2,arg3, msg,reply_received,1);
  676.  
  677.     return (aid_t) msg;
  678. }
  679.  
  680. /** Wait for a message sent by async framework
  681.  *
  682.  * @param amsgid Message ID to wait for
  683.  * @param retval Pointer to variable where will be stored retval
  684.  *               of the answered message. If NULL, it is ignored.
  685.  *
  686.  */
  687. void async_wait_for(aid_t amsgid, ipcarg_t *retval)
  688. {
  689.     amsg_t *msg = (amsg_t *) amsgid;
  690.  
  691.     futex_down(&async_futex);
  692.     if (msg->done) {
  693.         futex_up(&async_futex);
  694.         goto done;
  695.     }
  696.  
  697.     msg->wdata.ptid = psthread_get_id();
  698.     msg->wdata.active = 0;
  699.     msg->wdata.inlist = 0;
  700.     /* Leave locked async_futex when entering this function */
  701.     psthread_schedule_next_adv(PS_TO_MANAGER);
  702.     /* futex is up automatically after psthread_schedule_next...*/
  703. done:
  704.     if (retval)
  705.         *retval = msg->retval;
  706.     free(msg);
  707. }
  708.  
  709. /** Wait for a message sent by async framework with timeout
  710.  *
  711.  * @param amsgid Message ID to wait for
  712.  * @param retval Pointer to variable where will be stored retval
  713.  *               of the answered message. If NULL, it is ignored.
  714.  * @param timeout Timeout in usecs
  715.  * @return 0 on success, ETIMEOUT if timeout expired
  716.  *
  717.  */
  718. int async_wait_timeout(aid_t amsgid, ipcarg_t *retval, suseconds_t timeout)
  719. {
  720.     amsg_t *msg = (amsg_t *) amsgid;
  721.  
  722.     /* TODO: Let it go through the event read at least once */
  723.     if (timeout < 0)
  724.         return ETIMEOUT;
  725.  
  726.     futex_down(&async_futex);
  727.     if (msg->done) {
  728.         futex_up(&async_futex);
  729.         goto done;
  730.     }
  731.  
  732.     gettimeofday(&msg->wdata.expires, NULL);
  733.     tv_add(&msg->wdata.expires, timeout);
  734.  
  735.     msg->wdata.ptid = psthread_get_id();
  736.     msg->wdata.active = 0;
  737.     insert_timeout(&msg->wdata);
  738.  
  739.     /* Leave locked async_futex when entering this function */
  740.     psthread_schedule_next_adv(PS_TO_MANAGER);
  741.     /* futex is up automatically after psthread_schedule_next...*/
  742.  
  743.     if (!msg->done)
  744.         return ETIMEOUT;
  745.  
  746. done:
  747.     if (retval)
  748.         *retval = msg->retval;
  749.     free(msg);
  750.  
  751.     return 0;
  752. }
  753.  
  754. /** Wait specified time, but in the meantime handle incoming events
  755.  *
  756.  * @param timeout Time in microseconds to wait
  757.  */
  758. void async_usleep(suseconds_t timeout)
  759. {
  760.     amsg_t *msg;
  761.    
  762.     if (in_interrupt_handler) {
  763.         printf("Cannot call async_usleep in interrupt handler.\n");
  764.         _exit(1);
  765.     }
  766.  
  767.     msg = malloc(sizeof(*msg));
  768.     if (!msg)
  769.         return;
  770.  
  771.     msg->wdata.ptid = psthread_get_id();
  772.     msg->wdata.active = 0;
  773.  
  774.     gettimeofday(&msg->wdata.expires, NULL);
  775.     tv_add(&msg->wdata.expires, timeout);
  776.  
  777.     futex_down(&async_futex);
  778.     insert_timeout(&msg->wdata);
  779.     /* Leave locked async_futex when entering this function */
  780.     psthread_schedule_next_adv(PS_TO_MANAGER);
  781.     /* futex is up automatically after psthread_schedule_next...*/
  782.     free(msg);
  783. }
  784.  
  785. /** Set function that is called, IPC_M_CONNECT_ME_TO is received
  786.  *
  787.  * @param conn Function that will form new psthread.
  788.  */
  789. void async_set_client_connection(async_client_conn_t conn)
  790. {
  791.     client_connection = conn;
  792. }
  793. void async_set_interrupt_received(async_client_conn_t conn)
  794. {
  795.     interrupt_received = conn;
  796. }
  797.  
  798. /* Primitive functions for simple communication */
  799. void async_msg_3(int phoneid, ipcarg_t method, ipcarg_t arg1,
  800.          ipcarg_t arg2, ipcarg_t arg3)
  801. {
  802.     ipc_call_async_3(phoneid, method, arg1, arg2, arg3, NULL, NULL, !in_interrupt_handler);
  803. }
  804.  
  805. void async_msg_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2)
  806. {
  807.     ipc_call_async_2(phoneid, method, arg1, arg2, NULL, NULL, !in_interrupt_handler);
  808. }
  809.  
  810. /** @}
  811.  */
  812.