git.demorecorder.com Git - free-sw/xcb/libxcb/blob - src/xcb_in.c

   1 /* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
   2  *
   3  * Permission is hereby granted, free of charge, to any person obtaining a
   4  * copy of this software and associated documentation files (the "Software"),
   5  * to deal in the Software without restriction, including without limitation
   6  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   7  * and/or sell copies of the Software, and to permit persons to whom the
   8  * Software is furnished to do so, subject to the following conditions:
   9  *
  10  * The above copyright notice and this permission notice shall be included in
  11  * all copies or substantial portions of the Software.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  15  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  16  * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  17  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  18  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19  *
  20  * Except as contained in this notice, the names of the authors or their
  21  * institutions shall not be used in advertising or otherwise to promote the
  22  * sale, use or other dealings in this Software without prior written
  23  * authorization from the authors.
  24  */
  25
  26 /* Stuff that reads stuff from the server. */
  27
  28 #include <assert.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <stdio.h>
  33 #include <errno.h>
  34
  35 #include "xcb.h"
  36 #include "xcbext.h"
  37 #include "xcbint.h"
  38 #if USE_POLL
  39 #include <poll.h>
  40 #elif !defined _WIN32
  41 #include <sys/select.h>
  42 #endif
  43
  44 #ifdef _WIN32
  45 #include "xcb_windefs.h"
  46 #endif /* _WIN32 */
  47
  48 #define XCB_ERROR 0
  49 #define XCB_REPLY 1
  50 #define XCB_XGE_EVENT 35
  51
  52 struct event_list {
  53     xcb_generic_event_t *event;
  54     struct event_list *next;
  55 };
  56
  57 struct reply_list {
  58     void *reply;
  59     struct reply_list *next;
  60 };
  61
  62 typedef struct pending_reply {
  63     uint64_t first_request;
  64     uint64_t last_request;
  65     enum workarounds workaround;
  66     int flags;
  67     struct pending_reply *next;
  68 } pending_reply;
  69
  70 typedef struct reader_list {
  71     unsigned int request;
  72     pthread_cond_t *data;
  73     struct reader_list *next;
  74 } reader_list;
  75
  76 static void wake_up_next_reader(xcb_connection_t *c)
  77 {
  78     int pthreadret;
  79     if(c->in.readers)
  80         pthreadret = pthread_cond_signal(c->in.readers->data);
  81     else
  82         pthreadret = pthread_cond_signal(&c->in.event_cond);
  83     assert(pthreadret == 0);
  84 }
  85
  86 static int read_packet(xcb_connection_t *c)
  87 {
  88     xcb_generic_reply_t genrep;
  89     int length = 32;
  90     int eventlength = 0; /* length after first 32 bytes for GenericEvents */
  91     void *buf;
  92     pending_reply *pend = 0;
  93     struct event_list *event;
  94
  95     /* Wait for there to be enough data for us to read a whole packet */
  96     if(c->in.queue_len < length)
  97         return 0;
  98
  99     /* Get the response type, length, and sequence number. */
 100     memcpy(&genrep, c->in.queue, sizeof(genrep));
 101
 102     /* Compute 32-bit sequence number of this packet. */
 103     if((genrep.response_type & 0x7f) != XCB_KEYMAP_NOTIFY)
 104     {
 105         uint64_t lastread = c->in.request_read;
 106         c->in.request_read = (lastread & UINT64_C(0xffffffffffff0000)) | genrep.sequence;
 107         if(XCB_SEQUENCE_COMPARE(c->in.request_read, <, lastread))
 108             c->in.request_read += 0x10000;
 109         if(XCB_SEQUENCE_COMPARE(c->in.request_read, >, c->in.request_expected))
 110             c->in.request_expected = c->in.request_read;
 111
 112         if(c->in.request_read != lastread)
 113         {
 114             if(c->in.current_reply)
 115             {
 116                 _xcb_map_put(c->in.replies, lastread, c->in.current_reply);
 117                 c->in.current_reply = 0;
 118                 c->in.current_reply_tail = &c->in.current_reply;
 119             }
 120             c->in.request_completed = c->in.request_read - 1;
 121         }
 122
 123         while(c->in.pending_replies &&
 124               c->in.pending_replies->workaround != WORKAROUND_EXTERNAL_SOCKET_OWNER &&
 125               XCB_SEQUENCE_COMPARE (c->in.pending_replies->last_request, <=, c->in.request_completed))
 126         {
 127             pending_reply *oldpend = c->in.pending_replies;
 128             c->in.pending_replies = oldpend->next;
 129             if(!oldpend->next)
 130                 c->in.pending_replies_tail = &c->in.pending_replies;
 131             free(oldpend);
 132         }
 133
 134         if(genrep.response_type == XCB_ERROR)
 135             c->in.request_completed = c->in.request_read;
 136     }
 137
 138     if(genrep.response_type == XCB_ERROR || genrep.response_type == XCB_REPLY)
 139     {
 140         pend = c->in.pending_replies;
 141         if(pend &&
 142            !(XCB_SEQUENCE_COMPARE(pend->first_request, <=, c->in.request_read) &&
 143              (pend->workaround == WORKAROUND_EXTERNAL_SOCKET_OWNER ||
 144               XCB_SEQUENCE_COMPARE(c->in.request_read, <=, pend->last_request))))
 145             pend = 0;
 146     }
 147
 148     /* For reply packets, check that the entire packet is available. */
 149     if(genrep.response_type == XCB_REPLY)
 150     {
 151         if(pend && pend->workaround == WORKAROUND_GLX_GET_FB_CONFIGS_BUG)
 152         {
 153             uint32_t *p = (uint32_t *) c->in.queue;
 154             genrep.length = p[2] * p[3] * 2;
 155         }
 156         length += genrep.length * 4;
 157     }
 158
 159     /* XGE events may have sizes > 32 */
 160     if (genrep.response_type == XCB_XGE_EVENT)
 161     {
 162         eventlength = ((xcb_ge_event_t*)&genrep)->length * 4;
 163     }
 164
 165     buf = malloc(length + eventlength +
 166             (genrep.response_type == XCB_REPLY ? 0 : sizeof(uint32_t)));
 167     if(!buf)
 168     {
 169         _xcb_conn_shutdown(c);
 170         return 0;
 171     }
 172
 173     if(_xcb_in_read_block(c, buf, length) <= 0)
 174     {
 175         free(buf);
 176         return 0;
 177     }
 178
 179     /* pull in XGE event data if available, append after event struct */
 180     if (eventlength)
 181     {
 182         if(_xcb_in_read_block(c, &((xcb_generic_event_t*)buf)[1], eventlength) <= 0)
 183         {
 184             free(buf);
 185             return 0;
 186         }
 187     }
 188
 189     if(pend && (pend->flags & XCB_REQUEST_DISCARD_REPLY))
 190     {
 191         free(buf);
 192         return 1;
 193     }
 194
 195     if(genrep.response_type != XCB_REPLY)
 196         ((xcb_generic_event_t *) buf)->full_sequence = c->in.request_read;
 197
 198     /* reply, or checked error */
 199     if( genrep.response_type == XCB_REPLY ||
 200        (genrep.response_type == XCB_ERROR && pend && (pend->flags & XCB_REQUEST_CHECKED)))
 201     {
 202         reader_list *reader;
 203         struct reply_list *cur = malloc(sizeof(struct reply_list));
 204         if(!cur)
 205         {
 206             _xcb_conn_shutdown(c);
 207             free(buf);
 208             return 0;
 209         }
 210         cur->reply = buf;
 211         cur->next = 0;
 212         *c->in.current_reply_tail = cur;
 213         c->in.current_reply_tail = &cur->next;
 214         for(reader = c->in.readers;
 215             reader &&
 216             XCB_SEQUENCE_COMPARE_32(reader->request, <=, c->in.request_read);
 217             reader = reader->next)
 218         {
 219             if(XCB_SEQUENCE_COMPARE_32(reader->request, ==, c->in.request_read))
 220             {
 221                 pthread_cond_signal(reader->data);
 222                 break;
 223             }
 224         }
 225         return 1;
 226     }
 227
 228     /* event, or unchecked error */
 229     event = malloc(sizeof(struct event_list));
 230     if(!event)
 231     {
 232         _xcb_conn_shutdown(c);
 233         free(buf);
 234         return 0;
 235     }
 236     event->event = buf;
 237     event->next = 0;
 238     *c->in.events_tail = event;
 239     c->in.events_tail = &event->next;
 240     pthread_cond_signal(&c->in.event_cond);
 241     return 1; /* I have something for you... */
 242 }
 243
 244 static xcb_generic_event_t *get_event(xcb_connection_t *c)
 245 {
 246     struct event_list *cur = c->in.events;
 247     xcb_generic_event_t *ret;
 248     if(!c->in.events)
 249         return 0;
 250     ret = cur->event;
 251     c->in.events = cur->next;
 252     if(!cur->next)
 253         c->in.events_tail = &c->in.events;
 254     free(cur);
 255     return ret;
 256 }
 257
 258 static void free_reply_list(struct reply_list *head)
 259 {
 260     while(head)
 261     {
 262         struct reply_list *cur = head;
 263         head = cur->next;
 264         free(cur->reply);
 265         free(cur);
 266     }
 267 }
 268
 269 static int read_block(const int fd, void *buf, const ssize_t len)
 270 {
 271     int done = 0;
 272     while(done < len)
 273     {
 274 #ifndef _WIN32
 275         int ret = read(fd, ((char *) buf) + done, len - done);
 276 #else
 277         int ret = recv(fd, ((char *) buf) + done, len - done,0);
 278 #endif /* !_WIN32 */
 279
 280         if(ret > 0)
 281             done += ret;
 282 #ifndef _WIN32
 283         if(ret < 0 && errno == EAGAIN)
 284 #else
 285         if(ret == SOCKET_ERROR && WSAGetLastError() == WSAEWOULDBLOCK)
 286 #endif /* !_Win32 */
 287         {
 288 #if USE_POLL
 289             struct pollfd pfd;
 290             pfd.fd = fd;
 291             pfd.events = POLLIN;
 292             pfd.revents = 0;
 293             do {
 294                 ret = poll(&pfd, 1, -1);
 295             } while (ret == -1 && errno == EINTR);
 296 #else
 297             fd_set fds;
 298             FD_ZERO(&fds);
 299             FD_SET(fd, &fds);
 300
 301             /* Initializing errno here makes sure that for Win32 this loop will execute only once */
 302             errno = 0;
 303             do {
 304                 ret = select(fd + 1, &fds, 0, 0, 0);
 305             } while (ret == -1 && errno == EINTR);
 306 #endif /* USE_POLL */
 307         }
 308         if(ret <= 0)
 309             return ret;
 310     }
 311     return len;
 312 }
 313
 314 static int poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply, xcb_generic_error_t **error)
 315 {
 316     struct reply_list *head;
 317
 318     /* If an error occurred when issuing the request, fail immediately. */
 319     if(!request)
 320         head = 0;
 321     /* We've read requests past the one we want, so if it has replies we have
 322      * them all and they're in the replies map. */
 323     else if(XCB_SEQUENCE_COMPARE_32(request, <, c->in.request_read))
 324     {
 325         head = _xcb_map_remove(c->in.replies, request);
 326         if(head && head->next)
 327             _xcb_map_put(c->in.replies, request, head->next);
 328     }
 329     /* We're currently processing the responses to the request we want, and we
 330      * have a reply ready to return. So just return it without blocking. */
 331     else if(XCB_SEQUENCE_COMPARE_32(request, ==, c->in.request_read) && c->in.current_reply)
 332     {
 333         head = c->in.current_reply;
 334         c->in.current_reply = head->next;
 335         if(!head->next)
 336             c->in.current_reply_tail = &c->in.current_reply;
 337     }
 338     /* We know this request can't have any more replies, and we've already
 339      * established it doesn't have a reply now. Don't bother blocking. */
 340     else if(XCB_SEQUENCE_COMPARE_32(request, ==, c->in.request_completed))
 341         head = 0;
 342     /* We may have more replies on the way for this request: block until we're
 343      * sure. */
 344     else
 345         return 0;
 346
 347     if(error)
 348         *error = 0;
 349     *reply = 0;
 350
 351     if(head)
 352     {
 353         if(((xcb_generic_reply_t *) head->reply)->response_type == XCB_ERROR)
 354         {
 355             if(error)
 356                 *error = head->reply;
 357             else
 358                 free(head->reply);
 359         }
 360         else
 361             *reply = head->reply;
 362
 363         free(head);
 364     }
 365
 366     return 1;
 367 }
 368
 369 /* Public interface */
 370
 371 void *xcb_wait_for_reply(xcb_connection_t *c, unsigned int request, xcb_generic_error_t **e)
 372 {
 373     uint64_t widened_request;
 374     void *ret = 0;
 375     if(e)
 376         *e = 0;
 377     if(c->has_error)
 378         return 0;
 379
 380     pthread_mutex_lock(&c->iolock);
 381
 382     widened_request = (c->out.request & UINT64_C(0xffffffff00000000)) | request;
 383     if(widened_request > c->out.request)
 384         widened_request -= UINT64_C(1) << 32;
 385
 386     /* If this request has not been written yet, write it. */
 387     if(c->out.return_socket || _xcb_out_flush_to(c, widened_request))
 388     {
 389         pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
 390         reader_list reader;
 391         reader_list **prev_reader;
 392
 393         for(prev_reader = &c->in.readers;
 394             *prev_reader &&
 395             XCB_SEQUENCE_COMPARE_32((*prev_reader)->request, <=, request);
 396             prev_reader = &(*prev_reader)->next)
 397         {
 398             /* empty */;
 399         }
 400         reader.request = request;
 401         reader.data = &cond;
 402         reader.next = *prev_reader;
 403         *prev_reader = &reader;
 404
 405         while(!poll_for_reply(c, request, &ret, e))
 406             if(!_xcb_conn_wait(c, &cond, 0, 0))
 407                 break;
 408
 409         for(prev_reader = &c->in.readers;
 410             *prev_reader &&
 411             XCB_SEQUENCE_COMPARE_32((*prev_reader)->request, <=, request);
 412             prev_reader = &(*prev_reader)->next)
 413         {
 414             if(*prev_reader == &reader)
 415             {
 416                 *prev_reader = (*prev_reader)->next;
 417                 break;
 418             }
 419         }
 420         pthread_cond_destroy(&cond);
 421     }
 422
 423     wake_up_next_reader(c);
 424     pthread_mutex_unlock(&c->iolock);
 425     return ret;
 426 }
 427
 428 static void insert_pending_discard(xcb_connection_t *c, pending_reply **prev_next, uint64_t seq)
 429 {
 430     pending_reply *pend;
 431     pend = malloc(sizeof(*pend));
 432     if(!pend)
 433     {
 434         _xcb_conn_shutdown(c);
 435         return;
 436     }
 437
 438     pend->first_request = seq;
 439     pend->last_request = seq;
 440     pend->workaround = 0;
 441     pend->flags = XCB_REQUEST_DISCARD_REPLY;
 442     pend->next = *prev_next;
 443     *prev_next = pend;
 444
 445     if(!pend->next)
 446         c->in.pending_replies_tail = &pend->next;
 447 }
 448
 449 static void discard_reply(xcb_connection_t *c, unsigned int request)
 450 {
 451     pending_reply *pend = 0;
 452     pending_reply **prev_pend;
 453     uint64_t widened_request;
 454
 455     /* We've read requests past the one we want, so if it has replies we have
 456      * them all and they're in the replies map. */
 457     if(XCB_SEQUENCE_COMPARE_32(request, <, c->in.request_read))
 458     {
 459         struct reply_list *head;
 460         head = _xcb_map_remove(c->in.replies, request);
 461         while (head)
 462         {
 463             struct reply_list *next = head->next;
 464             free(head->reply);
 465             free(head);
 466             head = next;
 467         }
 468         return;
 469     }
 470
 471     /* We're currently processing the responses to the request we want, and we
 472      * have a reply ready to return. Free it, and mark the pend to free any further
 473      * replies. */
 474     if(XCB_SEQUENCE_COMPARE_32(request, ==, c->in.request_read) && c->in.current_reply)
 475     {
 476         struct reply_list *head;
 477         head = c->in.current_reply;
 478         c->in.current_reply = NULL;
 479         c->in.current_reply_tail = &c->in.current_reply;
 480         while (head)
 481         {
 482             struct reply_list *next = head->next;
 483             free(head->reply);
 484             free(head);
 485             head = next;
 486         }
 487
 488         pend = c->in.pending_replies;
 489         if(pend &&
 490             !(XCB_SEQUENCE_COMPARE(pend->first_request, <=, c->in.request_read) &&
 491              (pend->workaround == WORKAROUND_EXTERNAL_SOCKET_OWNER ||
 492               XCB_SEQUENCE_COMPARE(c->in.request_read, <=, pend->last_request))))
 493             pend = 0;
 494         if(pend)
 495             pend->flags |= XCB_REQUEST_DISCARD_REPLY;
 496         else
 497             insert_pending_discard(c, &c->in.pending_replies, c->in.request_read);
 498
 499         return;
 500     }
 501
 502     /* Walk the list of pending requests. Mark the first match for deletion. */
 503     for(prev_pend = &c->in.pending_replies; *prev_pend; prev_pend = &(*prev_pend)->next)
 504     {
 505         if(XCB_SEQUENCE_COMPARE_32((*prev_pend)->first_request, >, request))
 506             break;
 507
 508         if(XCB_SEQUENCE_COMPARE_32((*prev_pend)->first_request, ==, request))
 509         {
 510             /* Pending reply found. Mark for discard: */
 511             (*prev_pend)->flags |= XCB_REQUEST_DISCARD_REPLY;
 512             return;
 513         }
 514     }
 515
 516     /* Pending reply not found (likely due to _unchecked request). Create one: */
 517     widened_request = (c->out.request & UINT64_C(0xffffffff00000000)) | request;
 518     if(widened_request > c->out.request)
 519         widened_request -= UINT64_C(1) << 32;
 520
 521     insert_pending_discard(c, prev_pend, widened_request);
 522 }
 523
 524 void xcb_discard_reply(xcb_connection_t *c, unsigned int sequence)
 525 {
 526     if(c->has_error)
 527         return;
 528
 529     /* If an error occurred when issuing the request, fail immediately. */
 530     if(!sequence)
 531         return;
 532
 533     pthread_mutex_lock(&c->iolock);
 534     discard_reply(c, sequence);
 535     pthread_mutex_unlock(&c->iolock);
 536 }
 537
 538 int xcb_poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply, xcb_generic_error_t **error)
 539 {
 540     int ret;
 541     if(c->has_error)
 542     {
 543         *reply = 0;
 544         if(error)
 545             *error = 0;
 546         return 1; /* would not block */
 547     }
 548     assert(reply != 0);
 549     pthread_mutex_lock(&c->iolock);
 550     ret = poll_for_reply(c, request, reply, error);
 551     pthread_mutex_unlock(&c->iolock);
 552     return ret;
 553 }
 554
 555 xcb_generic_event_t *xcb_wait_for_event(xcb_connection_t *c)
 556 {
 557     xcb_generic_event_t *ret;
 558     if(c->has_error)
 559         return 0;
 560     pthread_mutex_lock(&c->iolock);
 561     /* get_event returns 0 on empty list. */
 562     while(!(ret = get_event(c)))
 563         if(!_xcb_conn_wait(c, &c->in.event_cond, 0, 0))
 564             break;
 565
 566     wake_up_next_reader(c);
 567     pthread_mutex_unlock(&c->iolock);
 568     return ret;
 569 }
 570
 571 xcb_generic_event_t *xcb_poll_for_event(xcb_connection_t *c)
 572 {
 573     xcb_generic_event_t *ret = 0;
 574     if(!c->has_error)
 575     {
 576         pthread_mutex_lock(&c->iolock);
 577         /* FIXME: follow X meets Z architecture changes. */
 578         ret = get_event(c);
 579         if(!ret && _xcb_in_read(c)) /* _xcb_in_read shuts down the connection on error */
 580             ret = get_event(c);
 581         pthread_mutex_unlock(&c->iolock);
 582     }
 583     return ret;
 584 }
 585
 586 xcb_generic_error_t *xcb_request_check(xcb_connection_t *c, xcb_void_cookie_t cookie)
 587 {
 588     /* FIXME: this could hold the lock to avoid syncing unnecessarily, but
 589      * that would require factoring the locking out of xcb_get_input_focus,
 590      * xcb_get_input_focus_reply, and xcb_wait_for_reply. */
 591     xcb_generic_error_t *ret;
 592     void *reply;
 593     if(c->has_error)
 594         return 0;
 595     if(XCB_SEQUENCE_COMPARE_32(cookie.sequence,>,c->in.request_expected)
 596        && XCB_SEQUENCE_COMPARE_32(cookie.sequence,>,c->in.request_completed))
 597     {
 598         free(xcb_get_input_focus_reply(c, xcb_get_input_focus(c), &ret));
 599         assert(!ret);
 600     }
 601     reply = xcb_wait_for_reply(c, cookie.sequence, &ret);
 602     assert(!reply);
 603     return ret;
 604 }
 605
 606 /* Private interface */
 607
 608 int _xcb_in_init(_xcb_in *in)
 609 {
 610     if(pthread_cond_init(&in->event_cond, 0))
 611         return 0;
 612     in->reading = 0;
 613
 614     in->queue_len = 0;
 615
 616     in->request_read = 0;
 617     in->request_completed = 0;
 618
 619     in->replies = _xcb_map_new();
 620     if(!in->replies)
 621         return 0;
 622
 623     in->current_reply_tail = &in->current_reply;
 624     in->events_tail = &in->events;
 625     in->pending_replies_tail = &in->pending_replies;
 626
 627     return 1;
 628 }
 629
 630 void _xcb_in_destroy(_xcb_in *in)
 631 {
 632     pthread_cond_destroy(&in->event_cond);
 633     free_reply_list(in->current_reply);
 634     _xcb_map_delete(in->replies, (void (*)(void *)) free_reply_list);
 635     while(in->events)
 636     {
 637         struct event_list *e = in->events;
 638         in->events = e->next;
 639         free(e->event);
 640         free(e);
 641     }
 642     while(in->pending_replies)
 643     {
 644         pending_reply *pend = in->pending_replies;
 645         in->pending_replies = pend->next;
 646         free(pend);
 647     }
 648 }
 649
 650 int _xcb_in_expect_reply(xcb_connection_t *c, uint64_t request, enum workarounds workaround, int flags)
 651 {
 652     pending_reply *pend = malloc(sizeof(pending_reply));
 653     assert(workaround != WORKAROUND_NONE || flags != 0);
 654     if(!pend)
 655     {
 656         _xcb_conn_shutdown(c);
 657         return 0;
 658     }
 659     pend->first_request = pend->last_request = request;
 660     pend->workaround = workaround;
 661     pend->flags = flags;
 662     pend->next = 0;
 663     *c->in.pending_replies_tail = pend;
 664     c->in.pending_replies_tail = &pend->next;
 665     return 1;
 666 }
 667
 668 void _xcb_in_replies_done(xcb_connection_t *c)
 669 {
 670     struct pending_reply *pend;
 671     if (c->in.pending_replies_tail != &c->in.pending_replies)
 672     {
 673         pend = container_of(c->in.pending_replies_tail, struct pending_reply, next);
 674         if(pend->workaround == WORKAROUND_EXTERNAL_SOCKET_OWNER)
 675         {
 676             pend->last_request = c->out.request;
 677             pend->workaround = WORKAROUND_NONE;
 678         }
 679     }
 680 }
 681
 682 int _xcb_in_read(xcb_connection_t *c)
 683 {
 684 #ifndef _WIN32
 685     int n = read(c->fd, c->in.queue + c->in.queue_len, sizeof(c->in.queue) - c->in.queue_len);
 686 #else
 687     int n = recv(c->fd, c->in.queue + c->in.queue_len, sizeof(c->in.queue) - c->in.queue_len,0);
 688 #endif /* !_WIN32 */
 689     if(n > 0)
 690         c->in.queue_len += n;
 691     while(read_packet(c))
 692         /* empty */;
 693 #ifndef _WIN32
 694     if((n > 0) || (n < 0 && errno == EAGAIN))
 695 #else
 696     if((n > 0) || (n < 0 && WSAGetLastError() == WSAEWOULDBLOCK))
 697 #endif /* !_WIN32 */
 698         return 1;
 699     _xcb_conn_shutdown(c);
 700     return 0;
 701 }
 702
 703 int _xcb_in_read_block(xcb_connection_t *c, void *buf, int len)
 704 {
 705     int done = c->in.queue_len;
 706     if(len < done)
 707         done = len;
 708
 709     memcpy(buf, c->in.queue, done);
 710     c->in.queue_len -= done;
 711     memmove(c->in.queue, c->in.queue + done, c->in.queue_len);
 712
 713     if(len > done)
 714     {
 715         int ret = read_block(c->fd, (char *) buf + done, len - done);
 716         if(ret <= 0)
 717         {
 718             _xcb_conn_shutdown(c);
 719             return ret;
 720         }
 721     }
 722
 723     return len;
 724 }