summaryrefslogtreecommitdiff
path: root/src/async-getprop.c
blob: 09f0a8bfb970e32b6b156d8590826f7920330b90 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
/* Asynchronous X property getting hack */

/*
 * Copyright (C) 2002 Havoc Pennington
 * Copyright (C) 1986, 1998  The Open Group
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation.
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name of The Open Group shall not be
 * used in advertising or otherwise to promote the sale, use or other dealings
 * in this Software without prior written authorization from The Open Group.
 */

#include <assert.h>

#undef DEBUG_SPEW
#ifdef DEBUG_SPEW
#include <stdio.h>
#endif

#include "async-getprop.h"

#define NEED_REPLIES
#include <X11/Xproto.h>
#include <X11/Xlibint.h>

#ifndef NULL
#define NULL ((void*)0)
#endif

typedef struct _ListNode ListNode;
typedef struct _AgPerDisplayData AgPerDisplayData;

struct _ListNode
{
  ListNode *next;
};

struct _AgGetPropertyTask
{
  ListNode node;
  
  AgPerDisplayData *dd;
  Window window;
  Atom property;

  unsigned long request_seq;
  int error;

  Atom actual_type;
  int  actual_format;

  unsigned long  n_items;
  unsigned long  bytes_after;
  unsigned char *data;

  Bool have_reply;
};

struct _AgPerDisplayData
{
  ListNode node;
  _XAsyncHandler async;
  
  Display *display;
  ListNode *pending_tasks;
  ListNode *pending_tasks_tail;
  ListNode *completed_tasks;
  ListNode *completed_tasks_tail;
  int n_tasks_pending;
  int n_tasks_completed;
};

static ListNode *display_datas = NULL;
static ListNode *display_datas_tail = NULL;

static void
append_to_list (ListNode **head,
                ListNode **tail,
                ListNode  *task)
{
  task->next = NULL;
  
  if (*tail == NULL)
    {
      assert (*head == NULL);
      *head = task;
      *tail = task;
    }
  else
    {
      (*tail)->next = task;
      *tail = task;
    }
}

static void
remove_from_list (ListNode **head,
                  ListNode **tail,
                  ListNode  *task)
{
  ListNode *prev;
  ListNode *node;

  prev = NULL;
  node = *head;
  while (node != NULL)
    {
      if (node == task)
        {
          if (prev)
            prev->next = node->next;
          else
            *head = node->next;

          if (node == *tail)
            *tail = prev;
          
          break;
        }
      
      prev = node;
      node = node->next;
    }

  /* can't remove what's not there */
  assert (node != NULL);

  node->next = NULL;
}

static void
move_to_completed (AgPerDisplayData  *dd,
                   AgGetPropertyTask *task)
{
  remove_from_list (&dd->pending_tasks,
                    &dd->pending_tasks_tail,
                    &task->node);
  
  append_to_list (&dd->completed_tasks,
                  &dd->completed_tasks_tail,
                  &task->node);

  dd->n_tasks_pending -= 1;
  dd->n_tasks_completed += 1;
}

static AgGetPropertyTask*
find_pending_by_request_sequence (AgPerDisplayData *dd,
                                  unsigned long     request_seq)
{
  ListNode *node;

  /* if the sequence is after our last pending task, we
   * aren't going to find a match
   */
  {
    AgGetPropertyTask *task = (AgGetPropertyTask*) dd->pending_tasks_tail;
    if (task != NULL)
      {
        if (task->request_seq < request_seq)
          return NULL;
        else if (task->request_seq == request_seq)
          return task; /* why not check this */
      }
  }

  /* Generally we should get replies in the order we sent
   * requests, so we should usually be using the task
   * at the head of the list, if we use any task at all.
   * I'm not sure this is 100% guaranteed, if it is,
   * it would be a big speedup.
   */
  
  node = dd->pending_tasks;
  while (node != NULL)
    {
      AgGetPropertyTask *task = (AgGetPropertyTask*) node;
      
      if (task->request_seq == request_seq)
        return task;
      
      node = node->next;
    }
  
  return NULL;
}

static Bool
async_get_property_handler (Display *dpy,
                            xReply  *rep,
                            char    *buf,
                            int      len,
                            XPointer data)
{
  xGetPropertyReply  replbuf;
  xGetPropertyReply *reply;
  AgGetPropertyTask *task;
  AgPerDisplayData *dd;
  int bytes_read;

  dd = (AgPerDisplayData*) data;
  
#if 0
  printf ("%s: seeing request seq %ld buflen %d\n", __FUNCTION__,
          dpy->last_request_read, len);
#endif
  
  task = find_pending_by_request_sequence (dd, dpy->last_request_read);

  if (task == NULL)
    return False;

  assert (dpy->last_request_read == task->request_seq);

  task->have_reply = True;
  move_to_completed (dd, task);
  
  /* read bytes so far */
  bytes_read = SIZEOF (xReply);

  if (rep->generic.type == X_Error)
    {
      xError errbuf;

      task->error = rep->error.errorCode;
      
#ifdef DEBUG_SPEW
      printf ("%s: error code = %d (ignoring error, eating %d bytes, generic.length = %ld)\n",
              __FUNCTION__, task->error, (SIZEOF (xError) - bytes_read),
              rep->generic.length);
#endif

      /* We return True (meaning we consumed the reply)
       * because otherwise it would invoke the X error handler,
       * and an async API is useless if you have to synchronously
       * trap X errors. Also GetProperty can always fail, pretty
       * much, so trapping errors is always what you want.
       *
       * We have to eat all the error reply data here.
       * (kind of a charade as we know sizeof(xError) == sizeof(xReply))
       *
       * Passing discard = True seems to break things; I don't understand
       * why, because there should be no extra data in an error reply,
       * right?
       */
      _XGetAsyncReply (dpy, (char *)&errbuf, rep, buf, len,
                       (SIZEOF (xError) - bytes_read) >> 2, /* in 32-bit words */
                       False); /* really seems like it should be True */
      
      return True;
    }

#ifdef DEBUG_SPEW
  printf ("%s: already read %d bytes reading %d more for total of %d; generic.length = %ld\n",
          __FUNCTION__, bytes_read, (SIZEOF (xGetPropertyReply) - bytes_read) >> 2,
          SIZEOF (xGetPropertyReply), rep->generic.length);
#endif

  /* (kind of a silly as we know sizeof(xGetPropertyReply) == sizeof(xReply)) */
  reply = (xGetPropertyReply *)
    _XGetAsyncReply (dpy, (char *)&replbuf, rep, buf, len,
                     (SIZEOF (xGetPropertyReply) - bytes_read) >> 2, /* in 32-bit words */
                     False); /* False means expecting more data to follow,
                              * don't eat the rest of the reply
                              */

  bytes_read = SIZEOF (xGetPropertyReply);

#ifdef DEBUG_SPEW
  printf ("%s: have reply propertyType = %ld format = %d n_items = %ld\n",
          __FUNCTION__, reply->propertyType, reply->format, reply->nItems);
#endif

  assert (task->data == NULL);

  /* This is all copied from XGetWindowProperty().  Not sure we should
   * LockDisplay(). Not sure I'm passing the right args to
   * XGetAsyncData(). Not sure about a lot of things.
   */

  /* LockDisplay (dpy); */

  if (reply->propertyType != None)
    {
      long nbytes, netbytes;

      /* this alignment macro from orbit2 */
#define ALIGN_VALUE(this, boundary) \
  (( ((unsigned long)(this)) + (((unsigned long)(boundary)) -1)) & (~(((unsigned long)(boundary))-1)))

      switch (reply->format)
        {
          /*
           * One extra byte is malloced than is needed to contain the property
           * data, but this last byte is null terminated and convenient for
           * returning string properties, so the client doesn't then have to
           * recopy the string to make it null terminated.
           */
        case 8:
          nbytes = reply->nItems;
          /* there's padding to word boundary */
          netbytes = ALIGN_VALUE (nbytes, 4);
          if (nbytes + 1 > 0 &&
              (task->data = (unsigned char *) Xmalloc ((unsigned)nbytes + 1)))
            {
#ifdef DEBUG_SPEW
              printf ("%s: already read %d bytes using %ld, more eating %ld more\n",
                      __FUNCTION__, bytes_read, nbytes, netbytes);
#endif
              /* _XReadPad (dpy, (char *) task->data, netbytes); */
              _XGetAsyncData (dpy, task->data, buf, len,
                              bytes_read, nbytes,
                              netbytes);
            }
          break;

        case 16:
          nbytes = reply->nItems * sizeof (short);
          netbytes = reply->nItems << 1;
          netbytes = ALIGN_VALUE (netbytes, 4); /* align to word boundary */
          if (nbytes + 1 > 0 &&
              (task->data = (unsigned char *) Xmalloc ((unsigned)nbytes + 1)))
            {
#ifdef DEBUG_SPEW
              printf ("%s: already read %d bytes using %ld more, eating %ld more\n",
                      __FUNCTION__, bytes_read, nbytes, netbytes);
#endif
              /* _XRead16Pad (dpy, (short *) task->data, netbytes); */
              _XGetAsyncData (dpy, task->data, buf, len,
                              bytes_read, nbytes, netbytes);
            }
          break;

        case 32:
          nbytes = reply->nItems * sizeof (long);
          netbytes = reply->nItems << 2;
          if (nbytes + 1 > 0 &&
              (task->data = (unsigned char *) Xmalloc ((unsigned)nbytes + 1)))
            {
#ifdef DEBUG_SPEW
              printf ("%s: already read %d bytes using %ld more, eating %ld more\n",
                      __FUNCTION__, bytes_read, nbytes, netbytes);
#endif
              /* _XRead32 (dpy, (long *) task->data, netbytes); */
              _XGetAsyncData (dpy, task->data, buf, len,
                              bytes_read, nbytes,
                              netbytes);
            }
          break;

        default:
          /*
           * This part of the code should never be reached.  If it is,
           * the server sent back a property with an invalid format.
           * This is a BadImplementation error.
           *
           * However this async GetProperty API doesn't report errors
           * via the standard X mechanism, so don't do anything about
           * it, other than store it in task->error.
           */
          {
#if 0
            xError error;
#endif
            
            task->error = BadImplementation;

#if 0
            error.sequenceNumber = task->request_seq;
            error.type = X_Error;
            error.majorCode = X_GetProperty;
            error.minorCode = 0;
            error.errorCode = BadImplementation;

            _XError (dpy, &error);
#endif
          }

          nbytes = netbytes = 0L;
          break;
        }

      if (task->data == NULL)
        {
          task->error = BadAlloc;

#ifdef DEBUG_SPEW
          printf ("%s: already read %d bytes eating %ld\n",
                  __FUNCTION__, bytes_read, netbytes);
#endif
          /* _XEatData (dpy, (unsigned long) netbytes); */
          _XGetAsyncData (dpy, NULL, buf, len,
                          bytes_read, 0, netbytes);

          /* UnlockDisplay (dpy); */
          return BadAlloc; /* not Success */
        }

      (task->data)[nbytes] = '\0';
    }

#ifdef DEBUG_SPEW
  printf ("%s: have data\n", __FUNCTION__);
#endif

  task->actual_type = reply->propertyType;
  task->actual_format = reply->format;
  task->n_items = reply->nItems;
  task->bytes_after = reply->bytesAfter;

  /* UnlockDisplay (dpy); */

  return True;
}

static AgPerDisplayData*
get_display_data (Display *display,
                  Bool     create)
{
  ListNode *node;
  AgPerDisplayData *dd;
  
  node = display_datas;
  while (node != NULL)
    {
      dd = (AgPerDisplayData*) node;
      
      if (dd->display == display)
        return dd;
      
      node = node->next;
    }

  if (!create)
    return NULL;
  
  dd = Xcalloc (1, sizeof (AgPerDisplayData));
  if (dd == NULL)
    return NULL;

  dd->display = display;
  dd->async.next = display->async_handlers;
  dd->async.handler = async_get_property_handler;
  dd->async.data = (XPointer) dd;
  dd->display->async_handlers = &dd->async;

  append_to_list (&display_datas,
                  &display_datas_tail,
                  &dd->node);
  
  return dd;
}

static void
maybe_free_display_data (AgPerDisplayData *dd)
{
  if (dd->pending_tasks == NULL &&
      dd->completed_tasks == NULL)
    {
      DeqAsyncHandler (dd->display, &dd->async);
      remove_from_list (&display_datas, &display_datas_tail,
                        &dd->node);
      XFree (dd);
    }
}

AgGetPropertyTask*
ag_task_create (Display *dpy,
                Window   window,
                Atom     property,
                long     offset,
                long     length,
                Bool     delete,
                Atom     req_type)
{
  AgGetPropertyTask *task;
  xGetPropertyReq *req;
  xError error;
  AgPerDisplayData *dd;  
  
  /* Fire up our request */
  LockDisplay (dpy);

  dd = get_display_data (dpy, True);
  if (dd == NULL)
    {
      UnlockDisplay (dpy);
      return NULL;
    }
  
  GetReq (GetProperty, req);
  req->window = window;
  req->property = property;
  req->type = req_type;
  req->delete = delete;
  req->longOffset = offset;
  req->longLength = length;

  error.sequenceNumber = dpy->request;

  /* Queue up our async task */
  task = Xcalloc (1, sizeof (AgGetPropertyTask));
  if (task == NULL)
    {
      UnlockDisplay (dpy);
      return NULL;
    }

  task->dd = dd;
  task->window = window;
  task->property = property;
  task->request_seq = dpy->request;

  append_to_list (&dd->pending_tasks,
                  &dd->pending_tasks_tail,
                  &task->node);
  dd->n_tasks_pending += 1;
  
  UnlockDisplay (dpy);

  SyncHandle ();

  return task;
}

static void
free_task (AgGetPropertyTask *task)
{
  remove_from_list (&task->dd->completed_tasks,
                    &task->dd->completed_tasks_tail,
                    &task->node);
  task->dd->n_tasks_completed -= 1;
  maybe_free_display_data (task->dd);
  XFree (task);
}

Status
ag_task_get_reply_and_free (AgGetPropertyTask  *task,
                            Atom               *actual_type,
                            int                *actual_format,
                            unsigned long      *nitems,
                            unsigned long      *bytesafter,
                            unsigned char     **prop)
{
  Display *dpy;

  *prop = NULL;

  dpy = task->dd->display; /* Xlib macros require a variable named "dpy" */
  
  if (task->error != Success)
    {
      Status s = task->error;

      free_task (task);
      
      return s;
    }

  if (!task->have_reply)
    {
      free_task (task);

      return BadAlloc; /* not Success */
    }

  *actual_type = task->actual_type;
  *actual_format = task->actual_format;
  *nitems = task->n_items;
  *bytesafter = task->bytes_after;

  *prop = task->data; /* pass out ownership of task->data */

  SyncHandle ();

  free_task (task);
  
  return Success;
}

Bool
ag_task_have_reply (AgGetPropertyTask *task)
{
  return task->have_reply;
}

Atom
ag_task_get_property (AgGetPropertyTask *task)
{
  return task->property;
}

Window
ag_task_get_window (AgGetPropertyTask *task)
{
  return task->window;
}

Display*
ag_task_get_display (AgGetPropertyTask *task)
{
  return task->dd->display;
}

AgGetPropertyTask*
ag_get_next_completed_task (Display *display)
{
  AgPerDisplayData *dd;

  dd = get_display_data (display, False);

  if (dd == NULL)
    return NULL;
  
#ifdef DEBUG_SPEW
  printf ("%d pending %d completed\n",
          dd->n_tasks_pending,
          dd->n_tasks_completed);
#endif

  return (AgGetPropertyTask*) dd->completed_tasks;
}