aboutsummaryrefslogtreecommitdiff
path: root/gdb/ser-mingw.c
blob: 79e186b842d0ab812082e3f3e4d72f1b671cf3af (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
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
/* Serial interface for local (hardwired) serial ports on Windows systems

   Copyright (C) 2006
   Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#include "defs.h"
#include "serial.h"
#include "ser-base.h"
#include "ser-tcp.h"

#include <windows.h>
#include <conio.h>

#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>

#include "gdb_assert.h"
#include "gdb_string.h"

void _initialize_ser_windows (void);

struct ser_windows_state
{
  int in_progress;
  OVERLAPPED ov;
  DWORD lastCommMask;
  HANDLE except_event;
};

/* Open up a real live device for serial I/O.  */

static int
ser_windows_open (struct serial *scb, const char *name)
{
  HANDLE h;
  struct ser_windows_state *state;
  COMMTIMEOUTS timeouts;

  /* Only allow COM ports.  */
  if (strncmp (name, "COM", 3) != 0)
    {
      errno = ENOENT;
      return -1;
    }

  h = CreateFile (name, GENERIC_READ | GENERIC_WRITE, 0, NULL,
		  OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
  if (h == INVALID_HANDLE_VALUE)
    {
      errno = ENOENT;
      return -1;
    }

  scb->fd = _open_osfhandle ((long) h, O_RDWR);
  if (scb->fd < 0)
    {
      errno = ENOENT;
      return -1;
    }

  if (!SetCommMask (h, EV_RXCHAR))
    {
      errno = EINVAL;
      return -1;
    }

  timeouts.ReadIntervalTimeout = MAXDWORD;
  timeouts.ReadTotalTimeoutConstant = 0;
  timeouts.ReadTotalTimeoutMultiplier = 0;
  timeouts.WriteTotalTimeoutConstant = 0;
  timeouts.WriteTotalTimeoutMultiplier = 0;
  if (!SetCommTimeouts (h, &timeouts))
    {
      errno = EINVAL;
      return -1;
    }

  state = xmalloc (sizeof (struct ser_windows_state));
  memset (state, 0, sizeof (struct ser_windows_state));
  scb->state = state;

  /* Create a manual reset event to watch the input buffer.  */
  state->ov.hEvent = CreateEvent (0, TRUE, FALSE, 0);

  /* Create a (currently unused) handle to record exceptions.  */
  state->except_event = CreateEvent (0, TRUE, FALSE, 0);

  return 0;
}

/* Wait for the output to drain away, as opposed to flushing (discarding)
   it.  */

static int
ser_windows_drain_output (struct serial *scb)
{
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);

  return (FlushFileBuffers (h) != 0) ? 0 : -1;
}

static int
ser_windows_flush_output (struct serial *scb)
{
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);

  return (PurgeComm (h, PURGE_TXCLEAR) != 0) ? 0 : -1;
}

static int
ser_windows_flush_input (struct serial *scb)
{
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);

  return (PurgeComm (h, PURGE_RXCLEAR) != 0) ? 0 : -1;
}

static int
ser_windows_send_break (struct serial *scb)
{
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);

  if (SetCommBreak (h) == 0)
    return -1;

  /* Delay for 250 milliseconds.  */
  Sleep (250);

  if (ClearCommBreak (h))
    return -1;

  return 0;
}

static void
ser_windows_raw (struct serial *scb)
{
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
  DCB state;

  if (GetCommState (h, &state) == 0)
    return;

  state.fParity = FALSE;
  state.fOutxCtsFlow = FALSE;
  state.fOutxDsrFlow = FALSE;
  state.fDtrControl = DTR_CONTROL_ENABLE;
  state.fDsrSensitivity = FALSE;
  state.fOutX = FALSE;
  state.fInX = FALSE;
  state.fNull = FALSE;
  state.fAbortOnError = FALSE;
  state.ByteSize = 8;
  state.Parity = NOPARITY;

  scb->current_timeout = 0;

  if (SetCommState (h, &state) == 0)
    warning (_("SetCommState failed\n"));
}

static int
ser_windows_setstopbits (struct serial *scb, int num)
{
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
  DCB state;

  if (GetCommState (h, &state) == 0)
    return -1;

  switch (num)
    {
    case SERIAL_1_STOPBITS:
      state.StopBits = ONESTOPBIT;
      break;
    case SERIAL_1_AND_A_HALF_STOPBITS:
      state.StopBits = ONE5STOPBITS;
      break;
    case SERIAL_2_STOPBITS:
      state.StopBits = TWOSTOPBITS;
      break;
    default:
      return 1;
    }

  return (SetCommState (h, &state) != 0) ? 0 : -1;
}

static int
ser_windows_setbaudrate (struct serial *scb, int rate)
{
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);
  DCB state;

  if (GetCommState (h, &state) == 0)
    return -1;

  state.BaudRate = rate;

  return (SetCommState (h, &state) != 0) ? 0 : -1;
}

static void
ser_windows_close (struct serial *scb)
{
  struct ser_windows_state *state;

  /* Stop any pending selects.  */
  CancelIo ((HANDLE) _get_osfhandle (scb->fd));
  state = scb->state;
  CloseHandle (state->ov.hEvent);
  CloseHandle (state->except_event);

  if (scb->fd < 0)
    return;

  close (scb->fd);
  scb->fd = -1;

  xfree (scb->state);
}

static void
ser_windows_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
{
  struct ser_windows_state *state;
  COMSTAT status;
  DWORD errors;
  HANDLE h = (HANDLE) _get_osfhandle (scb->fd);

  state = scb->state;

  *except = state->except_event;
  *read = state->ov.hEvent;

  if (state->in_progress)
    return;

  /* Reset the mask - we are only interested in any characters which
     arrive after this point, not characters which might have arrived
     and already been read.  */

  /* This really, really shouldn't be necessary - just the second one.
     But otherwise an internal flag for EV_RXCHAR does not get
     cleared, and we get a duplicated event, if the last batch
     of characters included at least two arriving close together.  */
  if (!SetCommMask (h, 0))
    warning (_("ser_windows_wait_handle: reseting mask failed"));

  if (!SetCommMask (h, EV_RXCHAR))
    warning (_("ser_windows_wait_handle: reseting mask failed (2)"));

  /* There's a potential race condition here; we must check cbInQue
     and not wait if that's nonzero.  */

  ClearCommError (h, &errors, &status);
  if (status.cbInQue > 0)
    {
      SetEvent (state->ov.hEvent);
      return;
    }

  state->in_progress = 1;
  ResetEvent (state->ov.hEvent);
  state->lastCommMask = -2;
  if (WaitCommEvent (h, &state->lastCommMask, &state->ov))
    {
      gdb_assert (state->lastCommMask & EV_RXCHAR);
      SetEvent (state->ov.hEvent);
    }
  else
    gdb_assert (GetLastError () == ERROR_IO_PENDING);
}

static int
ser_windows_read_prim (struct serial *scb, size_t count)
{
  struct ser_windows_state *state;
  OVERLAPPED ov;
  DWORD bytes_read, bytes_read_tmp;
  HANDLE h;
  gdb_byte *p;

  state = scb->state;
  if (state->in_progress)
    {
      WaitForSingleObject (state->ov.hEvent, INFINITE);
      state->in_progress = 0;
      ResetEvent (state->ov.hEvent);
    }

  memset (&ov, 0, sizeof (OVERLAPPED));
  ov.hEvent = CreateEvent (0, FALSE, FALSE, 0);
  h = (HANDLE) _get_osfhandle (scb->fd);

  if (!ReadFile (h, scb->buf, /* count */ 1, &bytes_read, &ov))
    {
      if (GetLastError () != ERROR_IO_PENDING
	  || !GetOverlappedResult (h, &ov, &bytes_read, TRUE))
	bytes_read = -1;
    }

  CloseHandle (ov.hEvent);
  return bytes_read;
}

static int
ser_windows_write_prim (struct serial *scb, const void *buf, size_t len)
{
  struct ser_windows_state *state;
  OVERLAPPED ov;
  DWORD bytes_written;
  HANDLE h;

  memset (&ov, 0, sizeof (OVERLAPPED));
  ov.hEvent = CreateEvent (0, FALSE, FALSE, 0);
  h = (HANDLE) _get_osfhandle (scb->fd);
  if (!WriteFile (h, buf, len, &bytes_written, &ov))
    {
      if (GetLastError () != ERROR_IO_PENDING
	  || !GetOverlappedResult (h, &ov, &bytes_written, TRUE))
	bytes_written = -1;
    }

  CloseHandle (ov.hEvent);
  return bytes_written;
}

struct ser_console_state
{
  HANDLE read_event;
  HANDLE except_event;

  HANDLE start_select;
  HANDLE stop_select;
  HANDLE exit_select;
  HANDLE have_stopped;

  HANDLE thread;
};

static DWORD WINAPI
console_select_thread (void *arg)
{
  struct serial *scb = arg;
  struct ser_console_state *state;
  int event_index;
  HANDLE h;

  state = scb->state;
  h = (HANDLE) _get_osfhandle (scb->fd);

  while (1)
    {
      HANDLE wait_events[2];
      INPUT_RECORD record;
      DWORD n_records;

      SetEvent (state->have_stopped);

      wait_events[0] = state->start_select;
      wait_events[1] = state->exit_select;

      if (WaitForMultipleObjects (2, wait_events, FALSE, INFINITE) != WAIT_OBJECT_0)
	return 0;

      ResetEvent (state->have_stopped);

    retry:
      wait_events[0] = state->stop_select;
      wait_events[1] = h;

      event_index = WaitForMultipleObjects (2, wait_events, FALSE, INFINITE);

      if (event_index == WAIT_OBJECT_0
	  || WaitForSingleObject (state->stop_select, 0) == WAIT_OBJECT_0)
	continue;

      if (event_index != WAIT_OBJECT_0 + 1)
	{
	  /* Wait must have failed; assume an error has occured, e.g.
	     the handle has been closed.  */
	  SetEvent (state->except_event);
	  continue;
	}

      /* We've got a pending event on the console.  See if it's
	 of interest.  */
      if (!PeekConsoleInput (h, &record, 1, &n_records) || n_records != 1)
	{
	  /* Something went wrong.  Maybe the console is gone.  */
	  SetEvent (state->except_event);
	  continue;
	}

      if (record.EventType == KEY_EVENT && record.Event.KeyEvent.bKeyDown)
	{
	  WORD keycode = record.Event.KeyEvent.wVirtualKeyCode;

	  /* Ignore events containing only control keys.  We must
	     recognize "enhanced" keys which we are interested in
	     reading via getch, if they do not map to ASCII.  But we
	     do not want to report input available for e.g. the
	     control key alone.  */

	  if (record.Event.KeyEvent.uChar.AsciiChar != 0
	      || keycode == VK_PRIOR
	      || keycode == VK_NEXT
	      || keycode == VK_END
	      || keycode == VK_HOME
	      || keycode == VK_LEFT
	      || keycode == VK_UP
	      || keycode == VK_RIGHT
	      || keycode == VK_DOWN
	      || keycode == VK_INSERT
	      || keycode == VK_DELETE)
	    {
	      /* This is really a keypress.  */
	      SetEvent (state->read_event);
	      continue;
	    }
	}

      /* Otherwise discard it and wait again.  */
      ReadConsoleInput (h, &record, 1, &n_records);
      goto retry;
    }
}

static int
fd_is_pipe (int fd)
{
  if (PeekNamedPipe ((HANDLE) _get_osfhandle (fd), NULL, 0, NULL, NULL, NULL))
    return 1;
  else
    return 0;
}

static DWORD WINAPI
pipe_select_thread (void *arg)
{
  struct serial *scb = arg;
  struct ser_console_state *state;
  int event_index;
  HANDLE h;

  state = scb->state;
  h = (HANDLE) _get_osfhandle (scb->fd);

  while (1)
    {
      HANDLE wait_events[2];
      DWORD n_avail;

      SetEvent (state->have_stopped);

      wait_events[0] = state->start_select;
      wait_events[1] = state->exit_select;

      if (WaitForMultipleObjects (2, wait_events, FALSE, INFINITE) != WAIT_OBJECT_0)
	return 0;

      ResetEvent (state->have_stopped);

    retry:
      if (!PeekNamedPipe (h, NULL, 0, NULL, &n_avail, NULL))
	{
	  SetEvent (state->except_event);
	  continue;
	}

      if (n_avail > 0)
	{
	  SetEvent (state->read_event);
	  continue;
	}

      /* Delay 10ms before checking again, but allow the stop event
	 to wake us.  */
      if (WaitForSingleObject (state->stop_select, 10) == WAIT_OBJECT_0)
	continue;

      goto retry;
    }
}

static void
ser_console_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
{
  struct ser_console_state *state = scb->state;

  if (state == NULL)
    {
      DWORD threadId;
      int is_tty;

      is_tty = isatty (scb->fd);
      if (!is_tty && !fd_is_pipe (scb->fd))
	{
	  *read = NULL;
	  *except = NULL;
	  return;
	}

      state = xmalloc (sizeof (struct ser_console_state));
      memset (state, 0, sizeof (struct ser_console_state));
      scb->state = state;

      /* Create auto reset events to wake, stop, and exit the select
	 thread.  */
      state->start_select = CreateEvent (0, FALSE, FALSE, 0);
      state->stop_select = CreateEvent (0, FALSE, FALSE, 0);
      state->exit_select = CreateEvent (0, FALSE, FALSE, 0);

      /* Create a manual reset event to signal whether the thread is
	 stopped.  This must be manual reset, because we may wait on
	 it multiple times without ever starting the thread.  */
      state->have_stopped = CreateEvent (0, TRUE, FALSE, 0);

      /* Create our own events to report read and exceptions separately.  */
      state->read_event = CreateEvent (0, FALSE, FALSE, 0);
      state->except_event = CreateEvent (0, FALSE, FALSE, 0);

      if (is_tty)
	state->thread = CreateThread (NULL, 0, console_select_thread, scb, 0,
				      &threadId);
      else
	state->thread = CreateThread (NULL, 0, pipe_select_thread, scb, 0,
				      &threadId);
    }

  *read = state->read_event;
  *except = state->except_event;

  /* Start from a blank state.  */
  ResetEvent (state->read_event);
  ResetEvent (state->except_event);
  ResetEvent (state->stop_select);

  /* First check for a key already in the buffer.  If there is one,
     we don't need a thread.  This also catches the second key of
     multi-character returns from getch, for instance for arrow
     keys.  The second half is in a C library internal buffer,
     and PeekConsoleInput will not find it.  */
  if (_kbhit ())
    {
      SetEvent (state->read_event);
      return;
    }

  /* Otherwise, start the select thread.  */
  SetEvent (state->start_select);
}

static void
ser_console_done_wait_handle (struct serial *scb)
{
  struct ser_console_state *state = scb->state;

  if (state == NULL)
    return;

  SetEvent (state->stop_select);
  WaitForSingleObject (state->have_stopped, INFINITE);
}

static void
ser_console_close (struct serial *scb)
{
  struct ser_console_state *state = scb->state;

  if (scb->state)
    {
      SetEvent (state->exit_select);

      WaitForSingleObject (state->thread, INFINITE);

      CloseHandle (state->start_select);
      CloseHandle (state->stop_select);
      CloseHandle (state->exit_select);
      CloseHandle (state->have_stopped);

      CloseHandle (state->read_event);
      CloseHandle (state->except_event);

      xfree (scb->state);
    }
}

struct ser_console_ttystate
{
  int is_a_tty;
};

static serial_ttystate
ser_console_get_tty_state (struct serial *scb)
{
  if (isatty (scb->fd))
    {
      struct ser_console_ttystate *state;
      state = (struct ser_console_ttystate *) xmalloc (sizeof *state);
      state->is_a_tty = 1;
      return state;
    }
  else
    return NULL;
}

struct pipe_state
{
  /* Since we use the pipe_select_thread for our select emulation,
     we need to place the state structure it requires at the front
     of our state.  */
  struct ser_console_state wait;

  /* The pex obj for our (one-stage) pipeline.  */
  struct pex_obj *pex;

  /* Streams for the pipeline's input and output.  */
  FILE *input, *output;
};

static struct pipe_state *
make_pipe_state (void)
{
  struct pipe_state *ps = XMALLOC (struct pipe_state);

  memset (ps, 0, sizeof (*ps));
  ps->wait.read_event = INVALID_HANDLE_VALUE;
  ps->wait.except_event = INVALID_HANDLE_VALUE;
  ps->wait.start_select = INVALID_HANDLE_VALUE;
  ps->wait.stop_select = INVALID_HANDLE_VALUE;

  return ps;
}

static void
free_pipe_state (struct pipe_state *ps)
{
  int saved_errno = errno;

  if (ps->wait.read_event != INVALID_HANDLE_VALUE)
    CloseHandle (ps->wait.read_event);
  if (ps->wait.except_event != INVALID_HANDLE_VALUE)
    CloseHandle (ps->wait.except_event);
  if (ps->wait.start_select != INVALID_HANDLE_VALUE)
    CloseHandle (ps->wait.start_select);

  /* If we have a select thread running, let the select thread free
     the stop event.  */
  if (ps->wait.stop_select != INVALID_HANDLE_VALUE)
    SetEvent (ps->wait.stop_select);

  /* Close the pipe to the child.  We must close the pipe before
     calling pex_free because pex_free will wait for the child to exit
     and the child will not exit until the pipe is closed.  */
  if (ps->input)
    fclose (ps->input);
  if (ps->pex)
    pex_free (ps->pex);
  /* pex_free closes ps->output.  */

  xfree (ps);

  errno = saved_errno;
}

static void
cleanup_pipe_state (void *untyped)
{
  struct pipe_state *ps = untyped;

  free_pipe_state (ps);
}

static int
pipe_windows_open (struct serial *scb, const char *name)
{
  char **argv = buildargv (name);
  struct cleanup *back_to = make_cleanup_freeargv (argv);
  if (! argv[0] || argv[0][0] == '\0')
    error ("missing child command");

  struct pipe_state *ps = make_pipe_state ();
  make_cleanup (cleanup_pipe_state, ps);

  ps->pex = pex_init (PEX_USE_PIPES, "target remote pipe", NULL);
  if (! ps->pex)
    goto fail;
  ps->input = pex_input_pipe (ps->pex, 1);
  if (! ps->input)
    goto fail;

  {
    int err;
    const char *err_msg
      = pex_run (ps->pex, PEX_SEARCH | PEX_BINARY_INPUT | PEX_BINARY_OUTPUT,
                 argv[0], argv, NULL, NULL,
                 &err);

    if (err_msg)
      {
        /* Our caller expects us to return -1, but all they'll do with
           it generally is print the message based on errno.  We have
           all the same information here, plus err_msg provided by
           pex_run, so we just raise the error here.  */
        if (err)
          error ("error starting child process '%s': %s: %s",
                 name, err_msg, safe_strerror (err));
        else
          error ("error starting child process '%s': %s",
                 name, err_msg);
      }
  }

  ps->output = pex_read_output (ps->pex, 1);
  if (! ps->output)
    goto fail;

  scb->fd = fileno (ps->output);
  scb->state = (void *) ps;

  discard_cleanups (back_to);
  return 0;

 fail:
  do_cleanups (back_to);
  return -1;
}


static void
pipe_windows_close (struct serial *scb)
{
  struct pipe_state *ps = scb->state;

  /* In theory, we should try to kill the subprocess here, but the pex
     interface doesn't give us enough information to do that.  Usually
     closing the input pipe will get the message across.  */

  free_pipe_state (ps);
}


static int
pipe_windows_read (struct serial *scb, size_t count)
{
  HANDLE pipeline_out = (HANDLE) _get_osfhandle (scb->fd);
  if (pipeline_out == INVALID_HANDLE_VALUE)
    return -1;

  DWORD available;
  if (! PeekNamedPipe (pipeline_out, NULL, 0, NULL, &available, NULL))
    return -1;

  if (count > available)
    count = available;

  DWORD bytes_read;
  if (! ReadFile (pipeline_out, scb->buf, count, &bytes_read, NULL))
    return -1;

  return bytes_read;
}


static int
pipe_windows_write (struct serial *scb, const void *buf, size_t count)
{
  struct pipe_state *ps = scb->state;
  int pipeline_in_fd = fileno (ps->input);
  if (pipeline_in_fd < 0)
    return -1;

  HANDLE pipeline_in = (HANDLE) _get_osfhandle (pipeline_in_fd);
  if (pipeline_in == INVALID_HANDLE_VALUE)
    return -1;

  DWORD written;
  if (! WriteFile (pipeline_in, buf, count, &written, NULL))
    return -1;

  return written;
}


static void
pipe_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
{
  struct pipe_state *ps = scb->state;

  /* Have we allocated our events yet?  */
  if (ps->wait.read_event == INVALID_HANDLE_VALUE)
    {
      DWORD threadId;

      /* Create auto reset events to wake and terminate the select thread.  */
      ps->wait.start_select = CreateEvent (0, FALSE, FALSE, 0);
      ps->wait.stop_select = CreateEvent (0, FALSE, FALSE, 0);

      /* Create our own events to report read and exceptions separately.
	 The exception event is currently never used.  */
      ps->wait.read_event = CreateEvent (0, FALSE, FALSE, 0);
      ps->wait.except_event = CreateEvent (0, FALSE, FALSE, 0);

      /* Start the select thread.  */
      CreateThread (NULL, 0, pipe_select_thread, scb, 0, &threadId);
    }

  ResetEvent (ps->wait.read_event);
  ResetEvent (ps->wait.except_event);

  SetEvent (ps->wait.start_select);

  *read = ps->wait.read_event;
  *except = ps->wait.except_event;
}


struct net_windows_state
{
  HANDLE read_event;
  HANDLE except_event;

  HANDLE start_select;
  HANDLE stop_select;
  HANDLE exit_select;
  HANDLE have_stopped;

  HANDLE sock_event;

  HANDLE thread;
};

static DWORD WINAPI
net_windows_select_thread (void *arg)
{
  struct serial *scb = arg;
  struct net_windows_state *state, state_copy;
  int event_index;

  state = scb->state;

  while (1)
    {
      HANDLE wait_events[2];
      WSANETWORKEVENTS events;

      SetEvent (state->have_stopped);

      wait_events[0] = state->start_select;
      wait_events[1] = state->exit_select;

      if (WaitForMultipleObjects (2, wait_events, FALSE, INFINITE) != WAIT_OBJECT_0)
	return 0;

      ResetEvent (state->have_stopped);

      wait_events[0] = state->stop_select;
      wait_events[1] = state->sock_event;

      event_index = WaitForMultipleObjects (2, wait_events, FALSE, INFINITE);

      if (event_index == WAIT_OBJECT_0
	  || WaitForSingleObject (state->stop_select, 0) == WAIT_OBJECT_0)
	continue;

      if (event_index != WAIT_OBJECT_0 + 1)
	{
	  /* Some error has occured.  Assume that this is an error
	     condition.  */
	  SetEvent (state->except_event);
	  continue;
	}

      /* Enumerate the internal network events, and reset the object that
	 signalled us to catch the next event.  */
      WSAEnumNetworkEvents (scb->fd, state->sock_event, &events);

      gdb_assert (events.lNetworkEvents & (FD_READ | FD_CLOSE));

      if (events.lNetworkEvents & FD_READ)
	SetEvent (state->read_event);

      if (events.lNetworkEvents & FD_CLOSE)
	SetEvent (state->except_event);
    }
}

static void
net_windows_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
{
  struct net_windows_state *state = scb->state;

  /* Start from a clean slate.  */
  ResetEvent (state->read_event);
  ResetEvent (state->except_event);
  ResetEvent (state->stop_select);

  *read = state->read_event;
  *except = state->except_event;

  /* Check any pending events.  This both avoids starting the thread
     unnecessarily, and handles stray FD_READ events (see below).  */
  if (WaitForSingleObject (state->sock_event, 0) == WAIT_OBJECT_0)
    {
      WSANETWORKEVENTS events;
      int any = 0;

      /* Enumerate the internal network events, and reset the object that
	 signalled us to catch the next event.  */
      WSAEnumNetworkEvents (scb->fd, state->sock_event, &events);

      /* You'd think that FD_READ or FD_CLOSE would be set here.  But,
	 sometimes, neither is.  I suspect that the FD_READ is set and
	 the corresponding event signalled while recv is running, and
	 the FD_READ is then lowered when recv consumes all the data,
	 but there's no way to un-signal the event.  This isn't a
	 problem for the call in net_select_thread, since any new
	 events after this point will not have been drained by recv.
	 It just means that we can't have the obvious assert here.  */

      /* If there is a read event, it might be still valid, or it might
	 not be - it may have been signalled before we last called
	 recv.  Double-check that there is data.  */
      if (events.lNetworkEvents & FD_READ)
	{
	  unsigned long available;

	  if (ioctlsocket (scb->fd, FIONREAD, &available) == 0
	      && available > 0)
	    {
	      SetEvent (state->read_event);
	      any = 1;
	    }
	  else
	    /* Oops, no data.  This call to recv will cause future
	       data to retrigger the event, e.g. while we are
	       in net_select_thread.  */
	    recv (scb->fd, NULL, 0, 0);
	}

      /* If there's a close event, then record it - it is obviously
	 still valid, and it will not be resignalled.  */
      if (events.lNetworkEvents & FD_CLOSE)
	{
	  SetEvent (state->except_event);
	  any = 1;
	}

      /* If we set either handle, there's no need to wake the thread.  */
      if (any)
	return;
    }

  /* Start the select thread.  */
  SetEvent (state->start_select);
}

static void
net_windows_done_wait_handle (struct serial *scb)
{
  struct net_windows_state *state = scb->state;

  SetEvent (state->stop_select);
  WaitForSingleObject (state->have_stopped, INFINITE);
}

static int
net_windows_open (struct serial *scb, const char *name)
{
  struct net_windows_state *state;
  int ret;
  DWORD threadId;

  ret = net_open (scb, name);
  if (ret != 0)
    return ret;

  state = xmalloc (sizeof (struct net_windows_state));
  memset (state, 0, sizeof (struct net_windows_state));
  scb->state = state;

  /* Create auto reset events to wake, stop, and exit the select
     thread.  */
  state->start_select = CreateEvent (0, FALSE, FALSE, 0);
  state->stop_select = CreateEvent (0, FALSE, FALSE, 0);
  state->exit_select = CreateEvent (0, FALSE, FALSE, 0);

  /* Create a manual reset event to signal whether the thread is
     stopped.  This must be manual reset, because we may wait on
     it multiple times without ever starting the thread.  */
  state->have_stopped = CreateEvent (0, TRUE, FALSE, 0);

  /* Associate an event with the socket.  */
  state->sock_event = CreateEvent (0, TRUE, FALSE, 0);
  WSAEventSelect (scb->fd, state->sock_event, FD_READ | FD_CLOSE);

  /* Create our own events to report read and close separately.  */
  state->read_event = CreateEvent (0, FALSE, FALSE, 0);
  state->except_event = CreateEvent (0, FALSE, FALSE, 0);

  /* And finally start the select thread.  */
  state->thread = CreateThread (NULL, 0, net_windows_select_thread, scb, 0,
				&threadId);

  return 0;
}


static void
net_windows_close (struct serial *scb)
{
  struct net_windows_state *state = scb->state;

  SetEvent (state->exit_select);
  WaitForSingleObject (state->thread, INFINITE);

  CloseHandle (state->read_event);
  CloseHandle (state->except_event);

  CloseHandle (state->start_select);
  CloseHandle (state->stop_select);
  CloseHandle (state->exit_select);
  CloseHandle (state->have_stopped);

  CloseHandle (state->sock_event);

  xfree (scb->state);

  net_close (scb);
}

void
_initialize_ser_windows (void)
{
  WSADATA wsa_data;
  struct serial_ops *ops;

  /* First register the serial port driver.  */

  ops = XMALLOC (struct serial_ops);
  memset (ops, 0, sizeof (struct serial_ops));
  ops->name = "hardwire";
  ops->next = 0;
  ops->open = ser_windows_open;
  ops->close = ser_windows_close;

  ops->flush_output = ser_windows_flush_output;
  ops->flush_input = ser_windows_flush_input;
  ops->send_break = ser_windows_send_break;

  /* These are only used for stdin; we do not need them for serial
     ports, so supply the standard dummies.  */
  ops->get_tty_state = ser_base_get_tty_state;
  ops->set_tty_state = ser_base_set_tty_state;
  ops->print_tty_state = ser_base_print_tty_state;
  ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;

  ops->go_raw = ser_windows_raw;
  ops->setbaudrate = ser_windows_setbaudrate;
  ops->setstopbits = ser_windows_setstopbits;
  ops->drain_output = ser_windows_drain_output;
  ops->readchar = ser_base_readchar;
  ops->write = ser_base_write;
  ops->async = ser_base_async;
  ops->read_prim = ser_windows_read_prim;
  ops->write_prim = ser_windows_write_prim;
  ops->wait_handle = ser_windows_wait_handle;

  serial_add_interface (ops);

  /* Next create the dummy serial driver used for terminals.  We only
     provide the TTY-related methods.  */

  ops = XMALLOC (struct serial_ops);
  memset (ops, 0, sizeof (struct serial_ops));

  ops->name = "terminal";
  ops->next = 0;

  ops->close = ser_console_close;
  ops->get_tty_state = ser_console_get_tty_state;
  ops->set_tty_state = ser_base_set_tty_state;
  ops->print_tty_state = ser_base_print_tty_state;
  ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
  ops->drain_output = ser_base_drain_output;
  ops->wait_handle = ser_console_wait_handle;
  ops->done_wait_handle = ser_console_done_wait_handle;

  serial_add_interface (ops);

  /* The pipe interface.  */

  ops = XMALLOC (struct serial_ops);
  memset (ops, 0, sizeof (struct serial_ops));
  ops->name = "pipe";
  ops->next = 0;
  ops->open = pipe_windows_open;
  ops->close = pipe_windows_close;
  ops->readchar = ser_base_readchar;
  ops->write = ser_base_write;
  ops->flush_output = ser_base_flush_output;
  ops->flush_input = ser_base_flush_input;
  ops->send_break = ser_base_send_break;
  ops->go_raw = ser_base_raw;
  ops->get_tty_state = ser_base_get_tty_state;
  ops->set_tty_state = ser_base_set_tty_state;
  ops->print_tty_state = ser_base_print_tty_state;
  ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
  ops->setbaudrate = ser_base_setbaudrate;
  ops->setstopbits = ser_base_setstopbits;
  ops->drain_output = ser_base_drain_output;
  ops->async = ser_base_async;
  ops->read_prim = pipe_windows_read;
  ops->write_prim = pipe_windows_write;
  ops->wait_handle = pipe_wait_handle;

  serial_add_interface (ops);

  /* If WinSock works, register the TCP/UDP socket driver.  */

  if (WSAStartup (MAKEWORD (1, 0), &wsa_data) != 0)
    /* WinSock is unavailable.  */
    return;

  ops = XMALLOC (struct serial_ops);
  memset (ops, 0, sizeof (struct serial_ops));
  ops->name = "tcp";
  ops->next = 0;
  ops->open = net_windows_open;
  ops->close = net_windows_close;
  ops->readchar = ser_base_readchar;
  ops->write = ser_base_write;
  ops->flush_output = ser_base_flush_output;
  ops->flush_input = ser_base_flush_input;
  ops->send_break = ser_base_send_break;
  ops->go_raw = ser_base_raw;
  ops->get_tty_state = ser_base_get_tty_state;
  ops->set_tty_state = ser_base_set_tty_state;
  ops->print_tty_state = ser_base_print_tty_state;
  ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
  ops->setbaudrate = ser_base_setbaudrate;
  ops->setstopbits = ser_base_setstopbits;
  ops->drain_output = ser_base_drain_output;
  ops->async = ser_base_async;
  ops->read_prim = net_read_prim;
  ops->write_prim = net_write_prim;
  ops->wait_handle = net_windows_wait_handle;
  ops->done_wait_handle = net_windows_done_wait_handle;
  serial_add_interface (ops);
}