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1351 palkovsky 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
 
1392 palkovsky 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() {
1407 palkovsky 63
 *      async_manager();
1392 palkovsky 64
 * }
65
 *
66
 *
1407 palkovsky 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);
1392 palkovsky 73
 *
1407 palkovsky 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);
1392 palkovsky 79
 *       ....
80
 * }
1404 palkovsky 81
 *
1405 decky 82
 * TODO: Detaching/joining dead psthreads?
1392 palkovsky 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>
1441 palkovsky 93
#include <time.h>
94
#include <arch/barrier.h>
1392 palkovsky 95
 
1463 palkovsky 96
atomic_t async_futex = FUTEX_INITIALIZER;
1392 palkovsky 97
static hash_table_t conn_hash_table;
1441 palkovsky 98
static LIST_INITIALIZE(timeout_list);
1392 palkovsky 99
 
100
typedef struct {
1427 palkovsky 101
    pstid_t ptid;                /**< Thread waiting for this message */
102
    int active;                  /**< If this thread is currently active */
103
    int done;                    /**< If reply was received */
104
    ipc_call_t *dataptr;         /**< Pointer where the answer data
105
                      *   should be stored */
1441 palkovsky 106
    struct timeval expires;      /**< Expiration time for waiting thread */
107
    int has_timeout;             /**< If true, this struct is in timeout list */
108
    link_t link;
109
 
1427 palkovsky 110
    ipcarg_t retval;
111
} amsg_t;
112
 
113
typedef struct {
1392 palkovsky 114
    link_t link;
115
    ipc_callid_t callid;
116
    ipc_call_t call;
117
} msg_t;
118
 
119
typedef struct {
120
    link_t link;
121
    ipcarg_t in_phone_hash;     /**< Incoming phone hash. */
122
    link_t msg_queue;              /**< Messages that should be delivered to this thread */
123
    pstid_t ptid;                /**< Thread associated with this connection */
124
    int active;                     /**< If this thread is currently active */
125
    /* Structures for connection opening packet */
126
    ipc_callid_t callid;
127
    ipc_call_t call;
1407 palkovsky 128
    void (*cthread)(ipc_callid_t,ipc_call_t *);
1392 palkovsky 129
} connection_t;
130
 
131
__thread connection_t *PS_connection;
132
 
1441 palkovsky 133
/** Add microseconds to give timeval */
134
static void tv_add(struct timeval *tv, suseconds_t usecs)
135
{
136
    tv->tv_sec += usecs / 1000000;
137
    tv->tv_usec += usecs % 1000000;
138
    if (tv->tv_usec > 1000000) {
139
        tv->tv_sec++;
140
        tv->tv_usec -= 1000000;
141
    }
142
}
143
 
144
/** Subtract 2 timevals, return microseconds difference */
145
static suseconds_t tv_sub(struct timeval *tv1, struct timeval *tv2)
146
{
147
    suseconds_t result;
148
 
149
    result = tv1->tv_usec - tv2->tv_usec;
150
    result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
151
 
152
    return result;
153
}
154
 
155
/** Compare timeval
156
 *
157
 * @return 1 if tv1 > tv2, otherwise 0
158
 */
159
static int tv_gt(struct timeval *tv1, struct timeval *tv2)
160
{
161
    if (tv1->tv_sec > tv2->tv_sec)
162
        return 1;
163
    if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
164
        return 1;
165
    return 0;
166
}
1466 palkovsky 167
static int tv_gteq(struct timeval *tv1, struct timeval *tv2)
168
{
169
    if (tv1->tv_sec > tv2->tv_sec)
170
        return 1;
171
    if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
172
        return 1;
173
    return 0;
174
}
1441 palkovsky 175
 
1392 palkovsky 176
/* Hash table functions */
1404 palkovsky 177
#define CONN_HASH_TABLE_CHAINS  32
1392 palkovsky 178
 
179
static hash_index_t conn_hash(unsigned long *key)
1351 palkovsky 180
{
1392 palkovsky 181
    assert(key);
1404 palkovsky 182
    return ((*key) >> 4) % CONN_HASH_TABLE_CHAINS;
1351 palkovsky 183
}
184
 
1392 palkovsky 185
static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
1351 palkovsky 186
{
1392 palkovsky 187
    connection_t *hs;
188
 
189
    hs = hash_table_get_instance(item, connection_t, link);
190
 
191
    return key[0] == hs->in_phone_hash;
1351 palkovsky 192
}
193
 
1392 palkovsky 194
static void conn_remove(link_t *item)
1351 palkovsky 195
{
1392 palkovsky 196
    free(hash_table_get_instance(item, connection_t, link));
1351 palkovsky 197
}
198
 
1392 palkovsky 199
 
200
/** Operations for NS hash table. */
201
static hash_table_operations_t conn_hash_table_ops = {
202
    .hash = conn_hash,
203
    .compare = conn_compare,
204
    .remove_callback = conn_remove
205
};
206
 
1427 palkovsky 207
/*************************************************/
208
 
1392 palkovsky 209
/** Try to route a call to an appropriate connection thread
210
 *
211
 */
212
static int route_call(ipc_callid_t callid, ipc_call_t *call)
1351 palkovsky 213
{
1392 palkovsky 214
    connection_t *conn;
215
    msg_t *msg;
216
    link_t *hlp;
217
    unsigned long key;
218
 
1427 palkovsky 219
    futex_down(&async_futex);
1392 palkovsky 220
 
221
    key = call->in_phone_hash;
222
    hlp = hash_table_find(&conn_hash_table, &key);
223
    if (!hlp) {
1427 palkovsky 224
        futex_up(&async_futex);
1392 palkovsky 225
        return 0;
1351 palkovsky 226
    }
1392 palkovsky 227
    conn = hash_table_get_instance(hlp, connection_t, link);
1351 palkovsky 228
 
1392 palkovsky 229
    msg = malloc(sizeof(*msg));
230
    msg->callid = callid;
231
    msg->call = *call;
232
    list_append(&msg->link, &conn->msg_queue);
233
 
234
    if (!conn->active) {
235
        conn->active = 1;
236
        psthread_add_ready(conn->ptid);
237
    }
1351 palkovsky 238
 
1427 palkovsky 239
    futex_up(&async_futex);
1392 palkovsky 240
 
241
    return 1;
242
}
243
 
1404 palkovsky 244
/** Return new incoming message for current(thread-local) connection */
1392 palkovsky 245
ipc_callid_t async_get_call(ipc_call_t *call)
246
{
247
    msg_t *msg;
248
    ipc_callid_t callid;
249
    connection_t *conn;
250
 
1466 palkovsky 251
    assert(PS_connection);
252
 
1427 palkovsky 253
    futex_down(&async_futex);
1392 palkovsky 254
 
255
    conn = PS_connection;
256
    /* If nothing in queue, wait until something appears */
257
    if (list_empty(&conn->msg_queue)) {
258
        conn->active = 0;
259
        psthread_schedule_next_adv(PS_TO_MANAGER);
1351 palkovsky 260
    }
261
 
1392 palkovsky 262
    msg = list_get_instance(conn->msg_queue.next, msg_t, link);
263
    list_remove(&msg->link);
264
    callid = msg->callid;
265
    *call = msg->call;
266
    free(msg);
267
 
1427 palkovsky 268
    futex_up(&async_futex);
1392 palkovsky 269
    return callid;
1351 palkovsky 270
}
271
 
1404 palkovsky 272
/** Thread function that gets created on new connection
273
 *
274
 * This function is defined as a weak symbol - to be redefined in
275
 * user code.
276
 */
1392 palkovsky 277
void client_connection(ipc_callid_t callid, ipc_call_t *call)
278
{
1404 palkovsky 279
    ipc_answer_fast(callid, ENOENT, 0, 0);
1392 palkovsky 280
}
1351 palkovsky 281
 
1453 palkovsky 282
/** Function that gets called on interrupt receival
1452 palkovsky 283
 *
284
 * This function is defined as a weak symbol - to be redefined in
285
 * user code.
286
 */
287
void interrupt_received(ipc_call_t *call)
288
{
289
}
290
 
291
 
1404 palkovsky 292
/** Wrapper for client connection thread
293
 *
294
 * When new connection arrives, thread with this function is created.
295
 * It calls client_connection and does final cleanup.
296
 *
297
 * @parameter arg Connection structure pointer
298
 */
1392 palkovsky 299
static int connection_thread(void  *arg)
1351 palkovsky 300
{
1404 palkovsky 301
    unsigned long key;
302
    msg_t *msg;
1408 palkovsky 303
    connection_t *conn;
1404 palkovsky 304
 
1392 palkovsky 305
    /* Setup thread local connection pointer */
306
    PS_connection = (connection_t *)arg;
1408 palkovsky 307
    conn = PS_connection;
308
    conn->cthread(conn->callid, &conn->call);
1392 palkovsky 309
 
1404 palkovsky 310
    /* Remove myself from connection hash table */
1427 palkovsky 311
    futex_down(&async_futex);
1408 palkovsky 312
    key = conn->in_phone_hash;
1404 palkovsky 313
    hash_table_remove(&conn_hash_table, &key, 1);
1427 palkovsky 314
    futex_up(&async_futex);
1404 palkovsky 315
    /* Answer all remaining messages with ehangup */
1408 palkovsky 316
    while (!list_empty(&conn->msg_queue)) {
317
        msg = list_get_instance(conn->msg_queue.next, msg_t, link);
1404 palkovsky 318
        list_remove(&msg->link);
319
        ipc_answer_fast(msg->callid, EHANGUP, 0, 0);
320
        free(msg);
321
    }
1351 palkovsky 322
}
1392 palkovsky 323
 
324
/** Create new thread for a new connection
325
 *
326
 * Creates new thread for connection, fills in connection
327
 * structures and inserts it into the hash table, so that
328
 * later we can easily do routing of messages to particular
329
 * threads.
1407 palkovsky 330
 *
1452 palkovsky 331
 * @param in_phone_hash Identification of the incoming connection
1407 palkovsky 332
 * @param callid Callid of the IPC_M_CONNECT_ME_TO packet
333
 * @param call Call data of the opening packet
334
 * @param cthread Thread function that should be called upon
335
 *                opening the connection
336
 * @return New thread id
1392 palkovsky 337
 */
1452 palkovsky 338
pstid_t async_new_connection(ipcarg_t in_phone_hash,ipc_callid_t callid,
339
                 ipc_call_t *call,
1407 palkovsky 340
                 void (*cthread)(ipc_callid_t,ipc_call_t *))
1392 palkovsky 341
{
342
    pstid_t ptid;
343
    connection_t *conn;
344
    unsigned long key;
345
 
346
    conn = malloc(sizeof(*conn));
347
    if (!conn) {
348
        ipc_answer_fast(callid, ENOMEM, 0, 0);
1407 palkovsky 349
        return NULL;
1392 palkovsky 350
    }
1452 palkovsky 351
    conn->in_phone_hash = in_phone_hash;
1392 palkovsky 352
    list_initialize(&conn->msg_queue);
353
    conn->ptid = psthread_create(connection_thread, conn);
354
    conn->callid = callid;
1453 palkovsky 355
    if (call)
356
        conn->call = *call;
1392 palkovsky 357
    conn->active = 1; /* We will activate it asap */
1407 palkovsky 358
    conn->cthread = cthread;
1392 palkovsky 359
    list_initialize(&conn->link);
360
    if (!conn->ptid) {
361
        free(conn);
362
        ipc_answer_fast(callid, ENOMEM, 0, 0);
1407 palkovsky 363
        return NULL;
1392 palkovsky 364
    }
365
    key = conn->in_phone_hash;
1427 palkovsky 366
    futex_down(&async_futex);
1392 palkovsky 367
    /* Add connection to hash table */
368
    hash_table_insert(&conn_hash_table, &key, &conn->link);
1427 palkovsky 369
    futex_up(&async_futex);
1392 palkovsky 370
 
371
    psthread_add_ready(conn->ptid);
1407 palkovsky 372
 
373
    return conn->ptid;
1392 palkovsky 374
}
375
 
1427 palkovsky 376
/** Handle call that was received */
1392 palkovsky 377
static void handle_call(ipc_callid_t callid, ipc_call_t *call)
378
{
1452 palkovsky 379
    /* Unrouted call - do some default behaviour */
1392 palkovsky 380
    switch (IPC_GET_METHOD(*call)) {
381
    case IPC_M_INTERRUPT:
1452 palkovsky 382
        interrupt_received(call);
383
        return;
1392 palkovsky 384
    case IPC_M_CONNECT_ME_TO:
385
        /* Open new connection with thread etc. */
1452 palkovsky 386
        async_new_connection(IPC_GET_ARG3(*call), callid, call, client_connection);
387
        return;
1392 palkovsky 388
    }
1452 palkovsky 389
 
390
    /* Try to route call through connection tables */
391
    if (route_call(callid, call))
392
        return;
393
 
394
    /* Unknown call from unknown phone - hang it up */
395
    ipc_answer_fast(callid, EHANGUP, 0, 0);
1392 palkovsky 396
}
397
 
1441 palkovsky 398
/** Fire all timeouts that expired */
399
static void handle_expired_timeouts(void)
400
{
401
    struct timeval tv;
402
    amsg_t *amsg;
403
    link_t *cur;
404
 
405
    gettimeofday(&tv,NULL);
406
    futex_down(&async_futex);
407
 
408
    cur = timeout_list.next;
409
    while (cur != &timeout_list) {
410
        amsg = list_get_instance(cur,amsg_t,link);
411
        if (tv_gt(&amsg->expires, &tv))
412
            break;
413
        cur = cur->next;
414
        list_remove(&amsg->link);
415
        amsg->has_timeout = 0;
416
        /* Redundant condition? The thread should not
417
         * be active when it gets here.
418
         */
419
        if (!amsg->active) {
420
            amsg->active = 1;
421
            psthread_add_ready(amsg->ptid);        
422
        }
423
    }
424
 
425
    futex_up(&async_futex);
426
}
427
 
1392 palkovsky 428
/** Endless loop dispatching incoming calls and answers */
1441 palkovsky 429
int async_manager(void)
1392 palkovsky 430
{
431
    ipc_call_t call;
432
    ipc_callid_t callid;
1435 palkovsky 433
    int timeout;
1441 palkovsky 434
    amsg_t *amsg;
435
    struct timeval tv;
1392 palkovsky 436
 
437
    while (1) {
438
        if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
1427 palkovsky 439
            futex_up(&async_futex); /* async_futex is always held
1392 palkovsky 440
                        * when entering manager thread
441
                        */
442
            continue;
443
        }
1441 palkovsky 444
        futex_down(&async_futex);
445
        if (!list_empty(&timeout_list)) {
446
            amsg = list_get_instance(timeout_list.next,amsg_t,link);
447
            gettimeofday(&tv,NULL);
1466 palkovsky 448
            if (tv_gteq(&tv, &amsg->expires)) {
1441 palkovsky 449
                handle_expired_timeouts();
450
                continue;
451
            } else
452
                timeout = tv_sub(&amsg->expires, &tv);
453
        } else
1435 palkovsky 454
            timeout = SYNCH_NO_TIMEOUT;
1441 palkovsky 455
        futex_up(&async_futex);
456
 
1435 palkovsky 457
        callid = ipc_wait_cycle(&call, timeout, SYNCH_BLOCKING);
1392 palkovsky 458
 
1435 palkovsky 459
        if (!callid) {
1441 palkovsky 460
            handle_expired_timeouts();
1435 palkovsky 461
            continue;
462
        }
463
 
1392 palkovsky 464
        if (callid & IPC_CALLID_ANSWERED)
465
            continue;
1427 palkovsky 466
 
1392 palkovsky 467
        handle_call(callid, &call);
468
    }
469
}
470
 
1404 palkovsky 471
/** Function to start async_manager as a standalone thread
472
 *
473
 * When more kernel threads are used, one async manager should
474
 * exist per thread. The particular implementation may change,
475
 * currently one async_manager is started automatically per kernel
476
 * thread except main thread.
477
 */
1392 palkovsky 478
static int async_manager_thread(void *arg)
479
{
1427 palkovsky 480
    futex_up(&async_futex); /* async_futex is always locked when entering
1392 palkovsky 481
                * manager */
482
    async_manager();
483
}
484
 
485
/** Add one manager to manager list */
486
void async_create_manager(void)
487
{
488
    pstid_t ptid;
489
 
490
    ptid = psthread_create(async_manager_thread, NULL);
491
    psthread_add_manager(ptid);
492
}
493
 
494
/** Remove one manager from manager list */
495
void async_destroy_manager(void)
496
{
497
    psthread_remove_manager();
498
}
499
 
500
/** Initialize internal structures needed for async manager */
501
int _async_init(void)
502
{
1404 palkovsky 503
    if (!hash_table_create(&conn_hash_table, CONN_HASH_TABLE_CHAINS, 1, &conn_hash_table_ops)) {
1392 palkovsky 504
        printf("%s: cannot create hash table\n", "async");
505
        return ENOMEM;
506
    }
507
 
508
}
1427 palkovsky 509
 
510
/** IPC handler for messages in async framework
511
 *
512
 * Notify thread that is waiting for this message, that it arrived
513
 */
514
static void reply_received(void *private, int retval,
515
               ipc_call_t *data)
516
{
517
    amsg_t *msg = (amsg_t *) private;
518
 
519
    msg->retval = retval;
520
 
521
    futex_down(&async_futex);
522
    /* Copy data after futex_down, just in case the
523
     * call was detached
524
     */
525
    if (msg->dataptr)
526
        *msg->dataptr = *data;
1435 palkovsky 527
 
1441 palkovsky 528
    write_barrier();
529
    /* Remove message from timeout list */
530
    if (msg->has_timeout)
531
        list_remove(&msg->link);
1427 palkovsky 532
    msg->done = 1;
533
    if (! msg->active) {
534
        msg->active = 1;
535
        psthread_add_ready(msg->ptid);
536
    }
537
    futex_up(&async_futex);
538
}
539
 
540
/** Send message and return id of the sent message
541
 *
542
 * The return value can be used as input for async_wait() to wait
543
 * for completion.
544
 */
545
aid_t async_send_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
546
           ipc_call_t *dataptr)
547
{
548
    amsg_t *msg;
549
 
550
    msg = malloc(sizeof(*msg));
551
    msg->active = 1;
552
    msg->done = 0;
553
    msg->dataptr = dataptr;
554
    ipc_call_async_2(phoneid,method,arg1,arg2,msg,reply_received);
555
 
556
    return (aid_t) msg;
557
}
558
 
559
/** Wait for a message sent by async framework
560
 *
561
 * @param amsgid Message ID to wait for
562
 * @param retval Pointer to variable where will be stored retval
563
 *               of the answered message. If NULL, it is ignored.
564
 *
565
 */
566
void async_wait_for(aid_t amsgid, ipcarg_t *retval)
567
{
568
    amsg_t *msg = (amsg_t *) amsgid;
569
    connection_t *conn;
570
 
571
    futex_down(&async_futex);
572
    if (msg->done) {
573
        futex_up(&async_futex);
574
        goto done;
575
    }
576
 
577
    msg->ptid = psthread_get_id();
578
    msg->active = 0;
1441 palkovsky 579
    msg->has_timeout = 0;
1427 palkovsky 580
    /* Leave locked async_futex when entering this function */
581
    psthread_schedule_next_adv(PS_TO_MANAGER);
582
    /* futex is up automatically after psthread_schedule_next...*/
583
done:
584
    if (retval)
585
        *retval = msg->retval;
586
    free(msg);
587
}
1435 palkovsky 588
 
1441 palkovsky 589
/** Insert sort timeout msg into timeouts list
590
 *
591
 * Assume async_futex is held
592
 */
593
static void insert_timeout(amsg_t *msg)
594
{
595
    link_t *tmp;
596
    amsg_t *cur;
1435 palkovsky 597
 
1441 palkovsky 598
    tmp = timeout_list.next;
599
    while (tmp != &timeout_list) {
600
        cur = list_get_instance(tmp, amsg_t, link);
1466 palkovsky 601
        if (tv_gteq(&cur->expires, &msg->expires))
1441 palkovsky 602
            break;
603
        tmp = tmp->next;
604
    }
605
    list_append(&msg->link, tmp);
606
}
1435 palkovsky 607
 
1441 palkovsky 608
/** Wait for a message sent by async framework with timeout
609
 *
610
 * @param amsgid Message ID to wait for
611
 * @param retval Pointer to variable where will be stored retval
612
 *               of the answered message. If NULL, it is ignored.
613
 * @param timeout Timeout in usecs
614
 * @return 0 on success, ETIMEOUT if timeout expired
615
 *
616
 */
617
int async_wait_timeout(aid_t amsgid, ipcarg_t *retval, suseconds_t timeout)
618
{
619
    amsg_t *msg = (amsg_t *) amsgid;
620
    connection_t *conn;
1435 palkovsky 621
 
1441 palkovsky 622
    futex_down(&async_futex);
623
    if (msg->done) {
624
        futex_up(&async_futex);
625
        goto done;
626
    }
1435 palkovsky 627
 
1441 palkovsky 628
    msg->ptid = psthread_get_id();
629
    msg->active = 0;
630
    msg->has_timeout = 1;
1435 palkovsky 631
 
1441 palkovsky 632
    gettimeofday(&msg->expires, NULL);
633
    tv_add(&msg->expires, timeout);
634
    insert_timeout(msg);
1435 palkovsky 635
 
1441 palkovsky 636
    /* Leave locked async_futex when entering this function */
637
    psthread_schedule_next_adv(PS_TO_MANAGER);
638
    /* futex is up automatically after psthread_schedule_next...*/
1435 palkovsky 639
 
1441 palkovsky 640
    if (!msg->done)
641
        return ETIMEOUT;
642
 
643
done:
644
    if (retval)
645
        *retval = msg->retval;
646
    free(msg);
647
 
648
    return 0;
649
}
650
 
1452 palkovsky 651
/** Wait specified time, but in the meantime handle incoming events
652
 *
653
 * @param timeout Time in microseconds to wait
654
 */
655
void async_usleep(suseconds_t timeout)
656
{
657
    amsg_t *msg;
658
 
659
    msg = malloc(sizeof(*msg));
660
    if (!msg)
661
        return;
662
 
663
    msg->ptid = psthread_get_id();
664
    msg->active = 0;
665
    msg->has_timeout = 1;
666
 
667
    gettimeofday(&msg->expires, NULL);
668
    tv_add(&msg->expires, timeout);
669
 
670
    futex_down(&async_futex);
671
    insert_timeout(msg);
672
    /* Leave locked async_futex when entering this function */
673
    psthread_schedule_next_adv(PS_TO_MANAGER);
674
    /* futex is up automatically after psthread_schedule_next...*/
675
    free(msg);
676
}