summaryrefslogtreecommitdiffstats
path: root/win/tclWinChan.c
blob: 6308930dd36731fb561c15eba12db52752c321b8 (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
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
/*
 * tclWinChan.c
 *
 *	Channel drivers for Windows channels based on files, command pipes and
 *	TCP sockets.
 *
 * Copyright (c) 1995-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclWinInt.h"
#include "tclIO.h"

/*
 * State flags used in the info structures below.
 */

#define FILE_PENDING	(1<<0)	/* Message is pending in the queue. */
#define FILE_ASYNC	(1<<1)	/* Channel is non-blocking. */
#define FILE_APPEND	(1<<2)	/* File is in append mode. */

#define FILE_TYPE_SERIAL  (FILE_TYPE_PIPE+1)
#define FILE_TYPE_CONSOLE (FILE_TYPE_PIPE+2)

/*
 * The following structure contains per-instance data for a file based channel.
 */

typedef struct FileInfo {
    Tcl_Channel channel;	/* Pointer to channel structure. */
    int validMask;		/* OR'ed combination of TCL_READABLE,
				 * TCL_WRITABLE, or TCL_EXCEPTION: indicates
				 * which operations are valid on the file. */
    int watchMask;		/* OR'ed combination of TCL_READABLE,
				 * TCL_WRITABLE, or TCL_EXCEPTION: indicates
				 * which events should be reported. */
    int flags;			/* State flags, see above for a list. */
    HANDLE handle;		/* Input/output file. */
    struct FileInfo *nextPtr;	/* Pointer to next registered file. */
    int dirty;			/* Boolean flag. Set if the OS may have data
				 * pending on the channel. */
} FileInfo;

typedef struct ThreadSpecificData {
    /*
     * List of all file channels currently open.
     */

    FileInfo *firstFilePtr;
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;

/*
 * The following structure is what is added to the Tcl event queue when file
 * events are generated.
 */

typedef struct FileEvent {
    Tcl_Event header;		/* Information that is standard for all
				 * events. */
    FileInfo *infoPtr;		/* Pointer to file info structure. Note that
				 * we still have to verify that the file
				 * exists before dereferencing this
				 * pointer. */
} FileEvent;

/*
 * Static routines for this file:
 */

static int		FileBlockProc(ClientData instanceData, int mode);
static void		FileChannelExitHandler(ClientData clientData);
static void		FileCheckProc(ClientData clientData, int flags);
static int		FileCloseProc(ClientData instanceData,
			    Tcl_Interp *interp);
static int		FileClose2Proc(ClientData instanceData,
			    Tcl_Interp *interp, int flags);
static int		FileEventProc(Tcl_Event *evPtr, int flags);
static int		FileGetHandleProc(ClientData instanceData,
			    int direction, ClientData *handlePtr);
static ThreadSpecificData *FileInit(void);
static int		FileInputProc(ClientData instanceData, char *buf,
			    int toRead, int *errorCode);
static int		FileOutputProc(ClientData instanceData,
			    const char *buf, int toWrite, int *errorCode);
static int		FileSeekProc(ClientData instanceData, long offset,
			    int mode, int *errorCode);
static Tcl_WideInt	FileWideSeekProc(ClientData instanceData,
			    Tcl_WideInt offset, int mode, int *errorCode);
static void		FileSetupProc(ClientData clientData, int flags);
static void		FileWatchProc(ClientData instanceData, int mask);
static void		FileThreadActionProc(ClientData instanceData,
			    int action);
static int		FileTruncateProc(ClientData instanceData,
			    Tcl_WideInt length);
static DWORD		FileGetType(HANDLE handle);
static int		NativeIsComPort(const WCHAR *nativeName);
static Tcl_Channel OpenFileChannel(HANDLE handle, char *channelName,
			    int permissions, int appendMode);

/*
 * This structure describes the channel type structure for file based IO.
 */

static const Tcl_ChannelType fileChannelType = {
    "file",			/* Type name. */
    TCL_CHANNEL_VERSION_5,	/* v5 channel */
    FileCloseProc,		/* Close proc. */
    FileInputProc,		/* Input proc. */
    FileOutputProc,		/* Output proc. */
    FileSeekProc,		/* Seek proc. */
    NULL,			/* Set option proc. */
    NULL,			/* Get option proc. */
    FileWatchProc,		/* Set up the notifier to watch the channel. */
    FileGetHandleProc,		/* Get an OS handle from channel. */
	FileClose2Proc,		/* close2proc. */
    FileBlockProc,		/* Set blocking or non-blocking mode.*/
    NULL,			/* flush proc. */
    NULL,			/* handler proc. */
    FileWideSeekProc,		/* Wide seek proc. */
    FileThreadActionProc,	/* Thread action proc. */
    FileTruncateProc		/* Truncate proc. */
};

/*
 *----------------------------------------------------------------------
 *
 * FileInit --
 *
 *	This function creates the window used to simulate file events.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Creates a new window and creates an exit handler.
 *
 *----------------------------------------------------------------------
 */

static ThreadSpecificData *
FileInit(void)
{
    ThreadSpecificData *tsdPtr =
	    (ThreadSpecificData *)TclThreadDataKeyGet(&dataKey);

    if (tsdPtr == NULL) {
	tsdPtr = TCL_TSD_INIT(&dataKey);
	tsdPtr->firstFilePtr = NULL;
	Tcl_CreateEventSource(FileSetupProc, FileCheckProc, NULL);
	Tcl_CreateThreadExitHandler(FileChannelExitHandler, NULL);
    }
    return tsdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * FileChannelExitHandler --
 *
 *	This function is called to cleanup the channel driver before Tcl is
 *	unloaded.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Destroys the communication window.
 *
 *----------------------------------------------------------------------
 */

static void
FileChannelExitHandler(
    ClientData clientData)	/* Old window proc */
{
    (void)clientData;

    Tcl_DeleteEventSource(FileSetupProc, FileCheckProc, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * FileSetupProc --
 *
 *	This function is invoked before Tcl_DoOneEvent blocks waiting for an
 *	event.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Adjusts the block time if needed.
 *
 *----------------------------------------------------------------------
 */

void
FileSetupProc(
    ClientData data,		/* Not used. */
    int flags)			/* Event flags as passed to Tcl_DoOneEvent. */
{
    FileInfo *infoPtr;
    Tcl_Time blockTime = { 0, 0 };
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    (void)data;

    if (!(flags & TCL_FILE_EVENTS)) {
	return;
    }

    /*
     * Check to see if there is a ready file. If so, poll.
     */

    for (infoPtr = tsdPtr->firstFilePtr; infoPtr != NULL;
	    infoPtr = infoPtr->nextPtr) {
	if (infoPtr->watchMask) {
	    Tcl_SetMaxBlockTime(&blockTime);
	    break;
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * FileCheckProc --
 *
 *	This function is called by Tcl_DoOneEvent to check the file event
 *	source for events.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May queue an event.
 *
 *----------------------------------------------------------------------
 */

static void
FileCheckProc(
    ClientData data,		/* Not used. */
    int flags)			/* Event flags as passed to Tcl_DoOneEvent. */
{
    FileEvent *evPtr;
    FileInfo *infoPtr;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    (void)data;

    if (!(flags & TCL_FILE_EVENTS)) {
	return;
    }

    /*
     * Queue events for any ready files that don't already have events queued
     * (caused by persistent states that won't generate WinSock events).
     */

    for (infoPtr = tsdPtr->firstFilePtr; infoPtr != NULL;
	    infoPtr = infoPtr->nextPtr) {
	if (infoPtr->watchMask && !(infoPtr->flags & FILE_PENDING)) {
	    infoPtr->flags |= FILE_PENDING;
	    evPtr = (FileEvent *)ckalloc(sizeof(FileEvent));
	    evPtr->header.proc = FileEventProc;
	    evPtr->infoPtr = infoPtr;
	    Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * FileEventProc --
 *
 *	This function is invoked by Tcl_ServiceEvent when a file event reaches
 *	the front of the event queue. This function invokes Tcl_NotifyChannel
 *	on the file.
 *
 * Results:
 *	Returns 1 if the event was handled, meaning it should be removed from
 *	the queue. Returns 0 if the event was not handled, meaning it should
 *	stay on the queue. The only time the event isn't handled is if the
 *	TCL_FILE_EVENTS flag bit isn't set.
 *
 * Side effects:
 *	Whatever the notifier callback does.
 *
 *----------------------------------------------------------------------
 */

static int
FileEventProc(
    Tcl_Event *evPtr,		/* Event to service. */
    int flags)			/* Flags that indicate what events to handle,
				 * such as TCL_FILE_EVENTS. */
{
    FileEvent *fileEvPtr = (FileEvent *)evPtr;
    FileInfo *infoPtr;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!(flags & TCL_FILE_EVENTS)) {
	return 0;
    }

    /*
     * Search through the list of watched files for the one whose handle
     * matches the event. We do this rather than simply dereferencing the
     * handle in the event so that files can be deleted while the event is in
     * the queue.
     */

    for (infoPtr = tsdPtr->firstFilePtr; infoPtr != NULL;
	    infoPtr = infoPtr->nextPtr) {
	if (fileEvPtr->infoPtr == infoPtr) {
	    infoPtr->flags &= ~(FILE_PENDING);
	    Tcl_NotifyChannel(infoPtr->channel, infoPtr->watchMask);
	    break;
	}
    }
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * FileBlockProc --
 *
 *	Set blocking or non-blocking mode on channel.
 *
 * Results:
 *	0 if successful, errno when failed.
 *
 * Side effects:
 *	Sets the device into blocking or non-blocking mode.
 *
 *----------------------------------------------------------------------
 */

static int
FileBlockProc(
    ClientData instanceData,	/* Instance data for channel. */
    int mode)			/* TCL_MODE_BLOCKING or
				 * TCL_MODE_NONBLOCKING. */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;

    /*
     * Files on Windows can not be switched between blocking and nonblocking,
     * hence we have to emulate the behavior. This is done in the input
     * function by checking against a bit in the state. We set or unset the
     * bit here to cause the input function to emulate the correct behavior.
     */

    if (mode == TCL_MODE_NONBLOCKING) {
	infoPtr->flags |= FILE_ASYNC;
    } else {
	infoPtr->flags &= ~(FILE_ASYNC);
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * FileCloseProc/FileClose2Proc --
 *
 *	Closes the IO channel.
 *
 * Results:
 *	0 if successful, the value of errno if failed.
 *
 * Side effects:
 *	Closes the physical channel
 *
 *----------------------------------------------------------------------
 */

static int
FileCloseProc(
    ClientData instanceData,	/* Pointer to FileInfo structure. */
    Tcl_Interp *interp)		/* Not used. */
{
    FileInfo *fileInfoPtr = (FileInfo *)instanceData;
    FileInfo *infoPtr;
    ThreadSpecificData *tsdPtr;
    int errorCode = 0;
    (void)interp;

    /*
     * Remove the file from the watch list.
     */

    FileWatchProc(instanceData, 0);

    /*
     * Don't close the Win32 handle if the handle is a standard channel during
     * the thread exit process. Otherwise, one thread may kill the stdio of
     * another.
     */

    if (!TclInThreadExit()
	    || ((GetStdHandle(STD_INPUT_HANDLE) != fileInfoPtr->handle)
	    &&  (GetStdHandle(STD_OUTPUT_HANDLE) != fileInfoPtr->handle)
	    &&  (GetStdHandle(STD_ERROR_HANDLE) != fileInfoPtr->handle))) {
	if (CloseHandle(fileInfoPtr->handle) == FALSE) {
	    TclWinConvertError(GetLastError());
	    errorCode = errno;
	}
    }

    /*
     * See if this FileInfo* is still on the thread local list.
     */

    tsdPtr = TCL_TSD_INIT(&dataKey);
    for (infoPtr = tsdPtr->firstFilePtr; infoPtr != NULL;
	    infoPtr = infoPtr->nextPtr) {
	if (infoPtr == fileInfoPtr) {
	    /*
	     * This channel exists on the thread local list. It should have
	     * been removed by an earlier Threadaction call, but do that now
	     * since just deallocating fileInfoPtr would leave an deallocated
	     * pointer on the thread local list.
	     */

	    FileThreadActionProc(fileInfoPtr,TCL_CHANNEL_THREAD_REMOVE);
	    break;
	}
    }
    ckfree(fileInfoPtr);
    return errorCode;
}

static int
FileClose2Proc(
    ClientData instanceData,	/* Pointer to FileInfo structure. */
    Tcl_Interp *interp,		/* Not used. */
	int flags)
{
    if ((flags & (TCL_CLOSE_READ | TCL_CLOSE_WRITE)) == 0) {
	return FileCloseProc(instanceData, interp);
    }
    return EINVAL;
}

/*
 *----------------------------------------------------------------------
 *
 * FileSeekProc --
 *
 *	Seeks on a file-based channel. Returns the new position.
 *
 * Results:
 *	-1 if failed, the new position if successful. If failed, it also sets
 *	*errorCodePtr to the error code.
 *
 * Side effects:
 *	Moves the location at which the channel will be accessed in future
 *	operations.
 *
 *----------------------------------------------------------------------
 */

static int
FileSeekProc(
    ClientData instanceData,	/* File state. */
    long offset,		/* Offset to seek to. */
    int mode,			/* Relative to where should we seek? */
    int *errorCodePtr)		/* To store error code. */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;
    LONG newPos, newPosHigh, oldPos, oldPosHigh;
    DWORD moveMethod;

    *errorCodePtr = 0;
    if (mode == SEEK_SET) {
	moveMethod = FILE_BEGIN;
    } else if (mode == SEEK_CUR) {
	moveMethod = FILE_CURRENT;
    } else {
	moveMethod = FILE_END;
    }

    /*
     * Save our current place in case we need to roll-back the seek.
     */

    oldPosHigh = 0;
    oldPos = (int)SetFilePointer(infoPtr->handle, 0, &oldPosHigh, FILE_CURRENT);
    if (oldPos == (LONG)INVALID_SET_FILE_POINTER) {
	DWORD winError = GetLastError();

	if (winError != NO_ERROR) {
	    TclWinConvertError(winError);
	    *errorCodePtr = errno;
	    return -1;
	}
    }

    newPosHigh = (offset < 0 ? -1 : 0);
    newPos = (int)SetFilePointer(infoPtr->handle, offset, &newPosHigh, moveMethod);
    if (newPos == (LONG)INVALID_SET_FILE_POINTER) {
	DWORD winError = GetLastError();

	if (winError != NO_ERROR) {
	    TclWinConvertError(winError);
	    *errorCodePtr = errno;
	    return -1;
	}
    }

    /*
     * Check for expressability in our return type, and roll-back otherwise.
     */

    if (newPosHigh != 0) {
	*errorCodePtr = EOVERFLOW;
	SetFilePointer(infoPtr->handle, oldPos, &oldPosHigh, FILE_BEGIN);
	return -1;
    }
    return (int) newPos;
}

/*
 *----------------------------------------------------------------------
 *
 * FileWideSeekProc --
 *
 *	Seeks on a file-based channel. Returns the new position.
 *
 * Results:
 *	-1 if failed, the new position if successful. If failed, it also sets
 *	*errorCodePtr to the error code.
 *
 * Side effects:
 *	Moves the location at which the channel will be accessed in future
 *	operations.
 *
 *----------------------------------------------------------------------
 */

static Tcl_WideInt
FileWideSeekProc(
    ClientData instanceData,	/* File state. */
    Tcl_WideInt offset,		/* Offset to seek to. */
    int mode,			/* Relative to where should we seek? */
    int *errorCodePtr)		/* To store error code. */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;
    DWORD moveMethod;
    LONG newPos, newPosHigh;

    *errorCodePtr = 0;
    if (mode == SEEK_SET) {
	moveMethod = FILE_BEGIN;
    } else if (mode == SEEK_CUR) {
	moveMethod = FILE_CURRENT;
    } else {
	moveMethod = FILE_END;
    }

    newPosHigh = Tcl_WideAsLong(offset >> 32);
    newPos = (int)SetFilePointer(infoPtr->handle, Tcl_WideAsLong(offset),
	    &newPosHigh, moveMethod);
    if (newPos == (LONG)INVALID_SET_FILE_POINTER) {
	DWORD winError = GetLastError();

	if (winError != NO_ERROR) {
	    TclWinConvertError(winError);
	    *errorCodePtr = errno;
	    return -1;
	}
    }
    return (((Tcl_WideInt)((unsigned)newPos)) | (Tcl_LongAsWide(newPosHigh) << 32));
}

/*
 *----------------------------------------------------------------------
 *
 * FileTruncateProc --
 *
 *	Truncates a file-based channel. Returns the error code.
 *
 * Results:
 *	0 if successful, POSIX-y error code if it failed.
 *
 * Side effects:
 *	Truncates the file, may move file pointers too.
 *
 *----------------------------------------------------------------------
 */

static int
FileTruncateProc(
    ClientData instanceData,	/* File state. */
    Tcl_WideInt length)		/* Length to truncate at. */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;
    LONG newPos, newPosHigh, oldPos, oldPosHigh;

    /*
     * Save where we were...
     */

    oldPosHigh = 0;
    oldPos = (int)SetFilePointer(infoPtr->handle, 0, &oldPosHigh, FILE_CURRENT);
    if (oldPos == (LONG)INVALID_SET_FILE_POINTER) {
	DWORD winError = GetLastError();
	if (winError != NO_ERROR) {
	    TclWinConvertError(winError);
	    return errno;
	}
    }

    /*
     * Move to where we want to truncate
     */

    newPosHigh = Tcl_WideAsLong(length >> 32);
    newPos = (int)SetFilePointer(infoPtr->handle, Tcl_WideAsLong(length),
	    &newPosHigh, FILE_BEGIN);
    if (newPos == (LONG)INVALID_SET_FILE_POINTER) {
	DWORD winError = GetLastError();
	if (winError != NO_ERROR) {
	    TclWinConvertError(winError);
	    return errno;
	}
    }

    /*
     * Perform the truncation (unlike POSIX ftruncate(), we needed to move to
     * the location to truncate at first).
     */

    if (!SetEndOfFile(infoPtr->handle)) {
	TclWinConvertError(GetLastError());
	return errno;
    }

    /*
     * Move back. If this last step fails, we don't care; it's just a "best
     * effort" attempt to restore our file pointer to where it was.
     */

    SetFilePointer(infoPtr->handle, oldPos, &oldPosHigh, FILE_BEGIN);
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * FileInputProc --
 *
 *	Reads input from the IO channel into the buffer given. Returns count
 *	of how many bytes were actually read, and an error indication.
 *
 * Results:
 *	A count of how many bytes were read is returned and an error
 *	indication is returned in an output argument.
 *
 * Side effects:
 *	Reads input from the actual channel.
 *
 *----------------------------------------------------------------------
 */

static int
FileInputProc(
    ClientData instanceData,	/* File state. */
    char *buf,			/* Where to store data read. */
    int bufSize,		/* Num bytes available in buffer. */
    int *errorCode)		/* Where to store error code. */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;
    DWORD bytesRead;

    *errorCode = 0;

    /*
     * TODO: This comment appears to be out of date.  We *do* have a
     * console driver, over in tclWinConsole.c.  After some Windows
     * developer confirms, this comment should be revised.
     *
     * Note that we will block on reads from a console buffer until a full
     * line has been entered. The only way I know of to get around this is to
     * write a console driver. We should probably do this at some point, but
     * for now, we just block. The same problem exists for files being read
     * over the network.
     */

    if (ReadFile(infoPtr->handle, (LPVOID) buf, (DWORD) bufSize, &bytesRead,
	    (LPOVERLAPPED) NULL) != FALSE) {
	return (int)bytesRead;
    }

    TclWinConvertError(GetLastError());
    *errorCode = errno;
    if (errno == EPIPE) {
	return 0;
    }
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * FileOutputProc --
 *
 *	Writes the given output on the IO channel. Returns count of how many
 *	characters were actually written, and an error indication.
 *
 * Results:
 *	A count of how many characters were written is returned and an error
 *	indication is returned in an output argument.
 *
 * Side effects:
 *	Writes output on the actual channel.
 *
 *----------------------------------------------------------------------
 */

static int
FileOutputProc(
    ClientData instanceData,	/* File state. */
    const char *buf,		/* The data buffer. */
    int toWrite,		/* How many bytes to write? */
    int *errorCode)		/* Where to store error code. */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;
    DWORD bytesWritten;

    *errorCode = 0;

    /*
     * If we are writing to a file that was opened with O_APPEND, we need to
     * seek to the end of the file before writing the current buffer.
     */

    if (infoPtr->flags & FILE_APPEND) {
	SetFilePointer(infoPtr->handle, 0, NULL, FILE_END);
    }

    if (WriteFile(infoPtr->handle, (LPVOID) buf, (DWORD) toWrite,
	    &bytesWritten, (LPOVERLAPPED) NULL) == FALSE) {
	TclWinConvertError(GetLastError());
	*errorCode = errno;
	return -1;
    }
    infoPtr->dirty = 1;
    return (int)bytesWritten;
}

/*
 *----------------------------------------------------------------------
 *
 * FileWatchProc --
 *
 *	Called by the notifier to set up to watch for events on this channel.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
FileWatchProc(
    ClientData instanceData,	/* File state. */
    int mask)			/* What events to watch for; OR-ed combination
				 * of TCL_READABLE, TCL_WRITABLE and
				 * TCL_EXCEPTION. */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;
    Tcl_Time blockTime = { 0, 0 };

    /*
     * Since the file is always ready for events, we set the block time to
     * zero so we will poll.
     */

    infoPtr->watchMask = mask & infoPtr->validMask;
    if (infoPtr->watchMask) {
	Tcl_SetMaxBlockTime(&blockTime);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * FileGetHandleProc --
 *
 *	Called from Tcl_GetChannelHandle to retrieve OS handles from a file
 *	based channel.
 *
 * Results:
 *	Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if there is no
 *	handle for the specified direction.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
FileGetHandleProc(
    ClientData instanceData,	/* The file state. */
    int direction,		/* TCL_READABLE or TCL_WRITABLE */
    ClientData *handlePtr)	/* Where to store the handle.  */
{
    FileInfo *infoPtr = (FileInfo *)instanceData;

    if (direction & infoPtr->validMask) {
	*handlePtr = (ClientData) infoPtr->handle;
	return TCL_OK;
    } else {
	return TCL_ERROR;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclpOpenFileChannel --
 *
 *	Open an File based channel on Unix systems.
 *
 * Results:
 *	The new channel or NULL. If NULL, the output argument errorCodePtr is
 *	set to a POSIX error.
 *
 * Side effects:
 *	May open the channel and may cause creation of a file on the file
 *	system.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
TclpOpenFileChannel(
    Tcl_Interp *interp,		/* Interpreter for error reporting; can be
				 * NULL. */
    Tcl_Obj *pathPtr,		/* Name of file to open. */
    int mode,			/* POSIX mode. */
    int permissions)		/* If the open involves creating a file, with
				 * what modes to create it? */
{
    Tcl_Channel channel = 0;
    int channelPermissions = 0;
    DWORD accessMode = 0, createMode, shareMode, flags;
    const WCHAR *nativeName;
    HANDLE handle;
    char channelName[16 + TCL_INTEGER_SPACE];
    TclFile readFile = NULL, writeFile = NULL;

    nativeName = (const WCHAR *)Tcl_FSGetNativePath(pathPtr);
    if (nativeName == NULL) {
	if (interp != (Tcl_Interp *) NULL) {
	    Tcl_AppendResult(interp, "couldn't open \"",
	    TclGetString(pathPtr), "\": filename is invalid on this platform",
	    NULL);
	}
	return NULL;
    }

    switch (mode & (O_RDONLY | O_WRONLY | O_RDWR)) {
    case O_RDONLY:
	accessMode = GENERIC_READ;
	channelPermissions = TCL_READABLE;
	break;
    case O_WRONLY:
	accessMode = GENERIC_WRITE;
	channelPermissions = TCL_WRITABLE;
	break;
    case O_RDWR:
	accessMode = (GENERIC_READ | GENERIC_WRITE);
	channelPermissions = (TCL_READABLE | TCL_WRITABLE);
	break;
    default:
	Tcl_Panic("TclpOpenFileChannel: invalid mode value");
	break;
    }

    /*
     * Map the creation flags to the NT create mode.
     */

    switch (mode & (O_CREAT | O_EXCL | O_TRUNC)) {
    case (O_CREAT | O_EXCL):
    case (O_CREAT | O_EXCL | O_TRUNC):
	createMode = CREATE_NEW;
	break;
    case (O_CREAT | O_TRUNC):
	createMode = CREATE_ALWAYS;
	break;
    case O_CREAT:
	createMode = OPEN_ALWAYS;
	break;
    case O_TRUNC:
    case (O_TRUNC | O_EXCL):
	createMode = TRUNCATE_EXISTING;
	break;
    default:
	createMode = OPEN_EXISTING;
	break;
    }

    /*
     * [2413550] Avoid double-open of serial ports on Windows
     * Special handling for Windows serial ports by a "name-hint"
     * to directly open it with the OVERLAPPED flag set.
     */

    if( NativeIsComPort(nativeName) ) {

	handle = TclWinSerialOpen(INVALID_HANDLE_VALUE, nativeName, accessMode);
	if (handle == INVALID_HANDLE_VALUE) {
	    TclWinConvertError(GetLastError());
	    if (interp != (Tcl_Interp *) NULL) {
		Tcl_AppendResult(interp, "couldn't open serial \"",
			TclGetString(pathPtr), "\": ",
			Tcl_PosixError(interp), NULL);
	    }
	    return NULL;
	}

	/*
	* For natively-named Windows serial ports we are done.
	*/
	channel = TclWinOpenSerialChannel(handle, channelName,
		channelPermissions);

	return channel;
    }
    /*
     * If the file is being created, get the file attributes from the
     * permissions argument, else use the existing file attributes.
     */

    if (mode & O_CREAT) {
	if (permissions & S_IWRITE) {
	    flags = FILE_ATTRIBUTE_NORMAL;
	} else {
	    flags = FILE_ATTRIBUTE_READONLY;
	}
    } else {
	flags = GetFileAttributesW(nativeName);
	if (flags == 0xFFFFFFFF) {
	    flags = 0;
	}
    }

    /*
     * Set up the file sharing mode.  We want to allow simultaneous access.
     */

    shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;

    /*
     * Now we get to create the file.
     */

    handle = CreateFileW(nativeName, accessMode, shareMode,
	    NULL, createMode, flags, (HANDLE) NULL);

    if (handle == INVALID_HANDLE_VALUE) {
	DWORD err = GetLastError();

	if ((err & 0xFFFFL) == ERROR_OPEN_FAILED) {
	    err = (mode & O_CREAT) ? ERROR_FILE_EXISTS : ERROR_FILE_NOT_FOUND;
	}
	TclWinConvertError(err);
	if (interp != (Tcl_Interp *) NULL) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "couldn't open \"%s\": %s",
		    TclGetString(pathPtr), Tcl_PosixError(interp)));
	}
	return NULL;
    }

    channel = NULL;

    switch (FileGetType(handle)) {
    case FILE_TYPE_SERIAL:
	/*
	 * Natively named serial ports "com1-9", "\\\\.\\comXX" are
	 * already done with the code above.
	 * Here we handle all other serial port names.
	 *
	 * Reopen channel for OVERLAPPED operation. Normally this shouldn't
	 * fail, because the channel exists.
	 */

	handle = TclWinSerialOpen(handle, nativeName, accessMode);
	if (handle == INVALID_HANDLE_VALUE) {
	    TclWinConvertError(GetLastError());
	    if (interp != (Tcl_Interp *) NULL) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"couldn't reopen serial \"%s\": %s",
			TclGetString(pathPtr), Tcl_PosixError(interp)));
	    }
	    return NULL;
	}
	channel = TclWinOpenSerialChannel(handle, channelName,
		channelPermissions);
	break;
    case FILE_TYPE_CONSOLE:
	channel = TclWinOpenConsoleChannel(handle, channelName,
		channelPermissions);
	break;
    case FILE_TYPE_PIPE:
	if (channelPermissions & TCL_READABLE) {
	    readFile = TclWinMakeFile(handle);
	}
	if (channelPermissions & TCL_WRITABLE) {
	    writeFile = TclWinMakeFile(handle);
	}
	channel = TclpCreateCommandChannel(readFile, writeFile, NULL, 0, NULL);
	break;
    case FILE_TYPE_CHAR:
    case FILE_TYPE_DISK:
    case FILE_TYPE_UNKNOWN:
	channel = OpenFileChannel(handle, channelName,
		channelPermissions, (mode & O_APPEND) ? FILE_APPEND : 0);
	break;

    default:
	/*
	 * The handle is of an unknown type, probably /dev/nul equivalent or
	 * possibly a closed handle.
	 */

	channel = NULL;
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't open \"%s\": bad file type",
		TclGetString(pathPtr)));
	Tcl_SetErrorCode(interp, "TCL", "VALUE", "CHANNEL", "BAD_TYPE",
		NULL);
	break;
    }

    return channel;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_MakeFileChannel --
 *
 *	Creates a Tcl_Channel from an existing platform specific file handle.
 *
 * Results:
 *	The Tcl_Channel created around the preexisting file.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_MakeFileChannel(
    ClientData rawHandle,	/* OS level handle */
    int mode)			/* OR'ed combination of TCL_READABLE and
				 * TCL_WRITABLE to indicate file mode. */
{
#if defined(HAVE_NO_SEH) && !defined(_WIN64) && !defined(__clang__)
    TCLEXCEPTION_REGISTRATION registration;
#endif
    char channelName[16 + TCL_INTEGER_SPACE];
    Tcl_Channel channel = NULL;
    HANDLE handle = (HANDLE) rawHandle;
    HANDLE dupedHandle;
    TclFile readFile = NULL, writeFile = NULL;
    BOOL result;

    if (mode == 0) {
	return NULL;
    }

    switch (FileGetType(handle)) {
    case FILE_TYPE_SERIAL:
	channel = TclWinOpenSerialChannel(handle, channelName, mode);
	break;
    case FILE_TYPE_CONSOLE:
	channel = TclWinOpenConsoleChannel(handle, channelName, mode);
	break;
    case FILE_TYPE_PIPE:
	if (mode & TCL_READABLE) {
	    readFile = TclWinMakeFile(handle);
	}
	if (mode & TCL_WRITABLE) {
	    writeFile = TclWinMakeFile(handle);
	}
	channel = TclpCreateCommandChannel(readFile, writeFile, NULL, 0, NULL);
	break;

    case FILE_TYPE_DISK:
    case FILE_TYPE_CHAR:
	channel = OpenFileChannel(handle, channelName, mode, 0);
	break;

    case FILE_TYPE_UNKNOWN:
    default:
	/*
	 * The handle is of an unknown type. Test the validity of this OS
	 * handle by duplicating it, then closing the dupe. The Win32 API
	 * doesn't provide an IsValidHandle() function, so we have to emulate
	 * it here. This test will not work on a console handle reliably,
	 * which is why we can't test every handle that comes into this
	 * function in this way.
	 */

	result = DuplicateHandle(GetCurrentProcess(), handle,
		GetCurrentProcess(), &dupedHandle, 0, FALSE,
		DUPLICATE_SAME_ACCESS);

	if (result == 0) {
	    /*
	     * Unable to make a duplicate. It's definitely invalid at this
	     * point.
	     */

	    return NULL;
	}

	/*
	 * Use structured exception handling (Win32 SEH) to protect the close
	 * of this duped handle which might throw EXCEPTION_INVALID_HANDLE.
	 */

	result = 0;
#if defined(HAVE_NO_SEH) && !defined(_WIN64) && !defined(__clang__)
	/*
	 * Don't have SEH available, do things the hard way. Note that this
	 * needs to be one block of asm, to avoid stack imbalance; also, it is
	 * illegal for one asm block to contain a jump to another.
	 */

	__asm__ __volatile__ (

	    /*
	     * Pick up parameters before messing with the stack
	     */

	    "movl       %[dupedHandle], %%ebx"          "\n\t"

	    /*
	     * Construct an TCLEXCEPTION_REGISTRATION to protect the call to
	     * CloseHandle.
	     */

	    "leal       %[registration], %%edx"         "\n\t"
	    "movl       %%fs:0,         %%eax"          "\n\t"
	    "movl       %%eax,          0x0(%%edx)"     "\n\t" /* link */
	    "leal       1f,             %%eax"          "\n\t"
	    "movl       %%eax,          0x4(%%edx)"     "\n\t" /* handler */
	    "movl       %%ebp,          0x8(%%edx)"     "\n\t" /* ebp */
	    "movl       %%esp,          0xC(%%edx)"     "\n\t" /* esp */
	    "movl       $0,             0x10(%%edx)"    "\n\t" /* status */

	    /*
	     * Link the TCLEXCEPTION_REGISTRATION on the chain.
	     */

	    "movl       %%edx,          %%fs:0"         "\n\t"

	    /*
	     * Call CloseHandle(dupedHandle).
	     */

	    "pushl      %%ebx"                          "\n\t"
	    "call       _CloseHandle@4"                 "\n\t"

	    /*
	     * Come here on normal exit. Recover the TCLEXCEPTION_REGISTRATION
	     * and put a TRUE status return into it.
	     */

	    "movl       %%fs:0,         %%edx"          "\n\t"
	    "movl	$1,		%%eax"		"\n\t"
	    "movl       %%eax,          0x10(%%edx)"    "\n\t"
	    "jmp        2f"                             "\n"

	    /*
	     * Come here on an exception. Recover the TCLEXCEPTION_REGISTRATION
	     */

	    "1:"                                        "\t"
	    "movl       %%fs:0,         %%edx"          "\n\t"
	    "movl       0x8(%%edx),     %%edx"          "\n\t"

	    /*
	     * Come here however we exited. Restore context from the
	     * TCLEXCEPTION_REGISTRATION in case the stack is unbalanced.
	     */

	    "2:"                                        "\t"
	    "movl       0xC(%%edx),     %%esp"          "\n\t"
	    "movl       0x8(%%edx),     %%ebp"          "\n\t"
	    "movl       0x0(%%edx),     %%eax"          "\n\t"
	    "movl       %%eax,          %%fs:0"         "\n\t"

	    :
	    /* No outputs */
	    :
	    [registration]  "m"     (registration),
	    [dupedHandle]   "m"	    (dupedHandle)
	    :
	    "%eax", "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"
	    );
	result = registration.status;
#else
#ifndef HAVE_NO_SEH
	__try {
#endif
	    CloseHandle(dupedHandle);
	    result = 1;
#ifndef HAVE_NO_SEH
	} __except (EXCEPTION_EXECUTE_HANDLER) {}
#endif
#endif
	if (result == FALSE) {
	    return NULL;
	}

	/*
	 * Fall through, the handle is valid.
	 *
	 * Create the undefined channel, anyways, because we know the handle
	 * is valid to something.
	 */

	channel = OpenFileChannel(handle, channelName, mode, 0);
    }

    return channel;
}

/*
 *----------------------------------------------------------------------
 *
 * TclpGetDefaultStdChannel --
 *
 *	Constructs a channel for the specified standard OS handle.
 *
 * Results:
 *	Returns the specified default standard channel, or NULL.
 *
 * Side effects:
 *	May cause the creation of a standard channel and the underlying file.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
TclpGetDefaultStdChannel(
    int type)			/* One of TCL_STDIN, TCL_STDOUT, or
				 * TCL_STDERR. */
{
    Tcl_Channel channel;
    HANDLE handle;
    int mode = -1;
    const char *bufMode = NULL;
    DWORD handleId = (DWORD) -1;
				/* Standard handle to retrieve. */

    switch (type) {
    case TCL_STDIN:
	handleId = STD_INPUT_HANDLE;
	mode = TCL_READABLE;
	bufMode = "line";
	break;
    case TCL_STDOUT:
	handleId = STD_OUTPUT_HANDLE;
	mode = TCL_WRITABLE;
	bufMode = "line";
	break;
    case TCL_STDERR:
	handleId = STD_ERROR_HANDLE;
	mode = TCL_WRITABLE;
	bufMode = "none";
	break;
    default:
	Tcl_Panic("TclGetDefaultStdChannel: Unexpected channel type");
	break;
    }

    handle = GetStdHandle(handleId);

    /*
     * Note that we need to check for 0 because Windows may return 0 if this
     * is not a console mode application, even though this is not a valid
     * handle.
     */

    if ((handle == INVALID_HANDLE_VALUE) || (handle == 0)) {
	return (Tcl_Channel) NULL;
    }

    channel = Tcl_MakeFileChannel(handle, mode);

    if (channel == NULL) {
	return (Tcl_Channel) NULL;
    }

    /*
     * Set up the normal channel options for stdio handles.
     */

    if (Tcl_SetChannelOption(NULL,channel,"-translation","auto")!=TCL_OK ||
	    Tcl_SetChannelOption(NULL,channel,"-eofchar","\032 {}")!=TCL_OK ||
	    Tcl_SetChannelOption(NULL,channel,"-buffering",bufMode)!=TCL_OK) {
	Tcl_Close(NULL, channel);
	return (Tcl_Channel) NULL;
    }
    return channel;
}

/*
 *----------------------------------------------------------------------
 *
 * OpenFileChannel --
 *
 *	Constructs a File channel for the specified standard OS handle. This
 *	is a helper function to break up the construction of channels into
 *	File, Console, or Serial.
 *
 * Results:
 *	Returns the new channel, or NULL.
 *
 * Side effects:
 *	May open the channel and may cause creation of a file on the file
 *	system.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
OpenFileChannel(
    HANDLE handle,		/* Win32 HANDLE to swallow */
    char *channelName,		/* Buffer to receive channel name */
    int permissions,		/* OR'ed combination of TCL_READABLE,
				 * TCL_WRITABLE, or TCL_EXCEPTION, indicating
				 * which operations are valid on the file. */
    int appendMode)		/* OR'ed combination of bits indicating what
				 * additional configuration of the channel is
				 * present. */
{
    FileInfo *infoPtr;
    ThreadSpecificData *tsdPtr = FileInit();

    /*
     * See if a channel with this handle already exists.
     */

    for (infoPtr = tsdPtr->firstFilePtr; infoPtr != NULL;
	    infoPtr = infoPtr->nextPtr) {
	if (infoPtr->handle == (HANDLE) handle) {
	    return (permissions==infoPtr->validMask) ? infoPtr->channel : NULL;
	}
    }

    infoPtr = (FileInfo *)ckalloc(sizeof(FileInfo));

    /*
     * TIP #218. Removed the code inserting the new structure into the global
     * list. This is now handled in the thread action callbacks, and only
     * there.
     */

    infoPtr->nextPtr = NULL;
    infoPtr->validMask = permissions;
    infoPtr->watchMask = 0;
    infoPtr->flags = appendMode;
    infoPtr->handle = handle;
    infoPtr->dirty = 0;
    snprintf(channelName, 16 + TCL_INTEGER_SPACE, "file%" TCL_Z_MODIFIER "x", (size_t) infoPtr);

    infoPtr->channel = Tcl_CreateChannel(&fileChannelType, channelName,
	    infoPtr, permissions);

    /*
     * Files have default translation of AUTO and ^Z eof char, which means
     * that a ^Z will be accepted as EOF when reading.
     */

    Tcl_SetChannelOption(NULL, infoPtr->channel, "-translation", "auto");
    Tcl_SetChannelOption(NULL, infoPtr->channel, "-eofchar", "\032 {}");

    return infoPtr->channel;
}

/*
 *----------------------------------------------------------------------
 *
 * TclWinFlushDirtyChannels --
 *
 *	Flush all dirty channels to disk, so that requesting the size of any
 *	file returns the correct value.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information is actually written to disk now, rather than later. Don't
 *	call this too often, or there will be a performance hit (i.e. only
 *	call when we need to ask for the size of a file).
 *
 *----------------------------------------------------------------------
 */

void
TclWinFlushDirtyChannels(void)
{
    FileInfo *infoPtr;
    ThreadSpecificData *tsdPtr = FileInit();

    /*
     * Flush all channels which are dirty, i.e. may have data pending in the
     * OS.
     */

    for (infoPtr = tsdPtr->firstFilePtr; infoPtr != NULL;
	    infoPtr = infoPtr->nextPtr) {
	if (infoPtr->dirty) {
	    FlushFileBuffers(infoPtr->handle);
	    infoPtr->dirty = 0;
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * FileThreadActionProc --
 *
 *	Insert or remove any thread local refs to this channel.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Changes thread local list of valid channels.
 *
 *----------------------------------------------------------------------
 */

static void
FileThreadActionProc(
    ClientData instanceData,
    int action)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    FileInfo *infoPtr = ( FileInfo *)instanceData;

    if (action == TCL_CHANNEL_THREAD_INSERT) {
	infoPtr->nextPtr = tsdPtr->firstFilePtr;
	tsdPtr->firstFilePtr = infoPtr;
    } else {
	FileInfo **nextPtrPtr;
	int removed = 0;

	for (nextPtrPtr = &(tsdPtr->firstFilePtr); (*nextPtrPtr) != NULL;
		nextPtrPtr = &((*nextPtrPtr)->nextPtr)) {
	    if ((*nextPtrPtr) == infoPtr) {
		(*nextPtrPtr) = infoPtr->nextPtr;
		removed = 1;
		break;
	    }
	}

	/*
	 * This could happen if the channel was created in one thread and then
	 * moved to another without updating the thread local data in each
	 * thread.
	 */

	if (!removed) {
	    Tcl_Panic("file info ptr not on thread channel list");
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * FileGetType --
 *
 *	Given a file handle, return its type
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

DWORD
FileGetType(
    HANDLE handle)		/* Opened file handle */
{
    DWORD type;

    type = GetFileType(handle);

    /*
     * If the file is a character device, we need to try to figure out whether
     * it is a serial port, a console, or something else. We test for the
     * console case first because this is more common.
     */

    if ((type == FILE_TYPE_CHAR)
	    || ((type == FILE_TYPE_UNKNOWN) && !GetLastError())) {
	DWORD consoleParams;

	if (GetConsoleMode(handle, &consoleParams)) {
	    type = FILE_TYPE_CONSOLE;
	} else {
	    DCB dcb;

	    dcb.DCBlength = sizeof(DCB);
	    if (GetCommState(handle, &dcb)) {
		type = FILE_TYPE_SERIAL;
	    }
	}
    }

    return type;
}

 /*
 *----------------------------------------------------------------------
 *
 * NativeIsComPort --
 *
 *	Determines if a path refers to a Windows serial port.
 *	A simple and efficient solution is to use a "name hint" to detect
 *      COM ports by their filename instead of resorting to a syscall
 *	to detect serialness after the fact.
 *	The following patterns cover common serial port names:
 *	    COM[1-9]
 *	    \\.\COM[0-9]+
 *
 * Results:
 *	1 = serial port, 0 = not.
 *
 *----------------------------------------------------------------------
 */

static int
NativeIsComPort(
    const WCHAR *nativePath)	/* Path of file to access, native encoding. */
{
    const WCHAR *p = (const WCHAR *) nativePath;
    int i, len = (int)wcslen(p);

    /*
     * 1. Look for com[1-9]:?
     */

    if ( (len == 4) && (_wcsnicmp(p, L"com", 3) == 0) ) {
	/*
	* The 4th character must be a digit 1..9
	*/

	if ( (p[3] < L'1') || (p[3] > L'9') ) {
	    return 0;
	}
	return 1;
    }

    /*
     * 2. Look for \\.\com[0-9]+
     */

    if ((len >= 8) && (_wcsnicmp(p, L"\\\\.\\com", 7) == 0)) {
	/*
	* Charaters 8..end must be a digits 0..9
	*/

	for ( i=7; i<len; i++ ) {
	    if ( (p[i] < '0') || (p[i] > '9') ) {
		return 0;
	    }
	}
	return 1;
    }
    return 0;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */