aboutsummaryrefslogblamecommitdiffstats
path: root/erts/emulator/sys/win32/sys.c
blob: 15d4cd73619c06513598bb4f82c4d1d9cfa816d2 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
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
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
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
                   

                                                        



                                                                      
  


                                                                         
  

















                                        
 

                               
                                 



























                                                                                


                                                        




















                                                                             
                                                  
                                                              


                                                                             



































                                                                            

                                                        





















































                                                                             









                                                      




























































































































































































































































































































































































































































































                                                                                              





                                                                                  
     































                                                                                 
     
                                                                                








































                                                                                  








































                                                                                        































































































































































































































































































                                                                                     





                                                    



                                                                                
 







































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































                                                                                                
























































































































































































































































































































































                                                                             






                                     








                                                                 

                                                                





                                              
 











                                                      
                        

























































































































































                                                                                        
/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 1996-2010. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */
/*
 * system-dependent functions
 *
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include "sys.h"
#include "erl_alloc.h"
#include "erl_sys_driver.h"
#include "global.h"
#include "erl_threads.h"
#include "../../drivers/win32/win_con.h"



void erts_sys_init_float(void);

void erl_start(int, char**);
void erl_exit(int n, char*, ...);
void erl_error(char*, va_list);
void erl_crash_dump(char*, int, char*, ...);

/*
 * Microsoft-specific function to map a WIN32 error code to a Posix errno.
 */
extern void _dosmaperr(DWORD);

#ifdef ERL_RUN_SHARED_LIB
#ifdef __argc
#undef __argc
#endif
#define __argc e_argc
#ifdef __argv
#undef __argv
#endif
#define __argv e_argv
#endif

static void init_console();
static int get_and_remove_option(int* argc, char** argv, const char* option);
static char *get_and_remove_option2(int *argc, char **argv, 
				    const char *option);
static int init_async_io(struct async_io* aio, int use_threads);
static void release_async_io(struct async_io* aio, ErlDrvPort);
static void async_read_file(struct async_io* aio, LPVOID buf, DWORD numToRead);
static int async_write_file(struct async_io* aio, LPVOID buf, DWORD numToWrite);
static int get_overlapped_result(struct async_io* aio,
				 LPDWORD pBytesRead, BOOL wait);
static BOOL CreateChildProcess(char *, HANDLE, HANDLE,
			       HANDLE, LPHANDLE, BOOL,
			       LPVOID, LPTSTR, unsigned,
			       char **, int *);
static int create_pipe(LPHANDLE, LPHANDLE, BOOL, BOOL);
static int ApplicationType(const char* originalName, char fullPath[MAX_PATH],
			   BOOL search_in_path, BOOL handle_quotes,
			   int *error_return);

HANDLE erts_service_event;

#ifdef ERTS_SMP
static erts_smp_tsd_key_t win32_errstr_key;
#endif

static erts_smp_atomic_t pipe_creation_counter;

static erts_smp_mtx_t sys_driver_data_lock;


/* Results from ApplicationType is one of */
#define APPL_NONE 0
#define APPL_DOS  1
#define APPL_WIN3X 2
#define APPL_WIN32 3

static int driver_write(long, HANDLE, byte*, int);
static void common_stop(int);
static int create_file_thread(struct async_io* aio, int mode);
#ifdef ERTS_SMP
static void close_active_handles(ErlDrvPort, const HANDLE* handles, int cnt);
static DWORD WINAPI threaded_handle_closer(LPVOID param);
#endif
static DWORD WINAPI threaded_reader(LPVOID param);
static DWORD WINAPI threaded_writer(LPVOID param);
static DWORD WINAPI threaded_exiter(LPVOID param);

#ifdef DEBUG
static void debug_console(void);
#endif

BOOL WINAPI ctrl_handler(DWORD dwCtrlType);

#define PORT_BUFSIZ 4096

#define PORT_FREE (-1)
#define PORT_EXITING (-2)

#define DRV_BUF_ALLOC(SZ) \
  erts_alloc_fnf(ERTS_ALC_T_DRV_DATA_BUF, (SZ))
#define DRV_BUF_REALLOC(P, SZ) \
  erts_realloc_fnf(ERTS_ALC_T_DRV_DATA_BUF, (P), (SZ))
#define DRV_BUF_FREE(P) \
  erts_free(ERTS_ALC_T_DRV_DATA_BUF, (P))

/********************* General functions ****************************/

/*
 * Whether create_pipe() should use a named pipe or an anonymous.
 * (Named pipes are not supported on Windows 95.)
 */

static int max_files = 1024;

static BOOL use_named_pipes;
static BOOL win_console = FALSE;


static OSVERSIONINFO int_os_version;	/* Version information for Win32. */

#ifdef ERTS_SMP
static BOOL (WINAPI *fpCancelIoEx)(HANDLE,LPOVERLAPPED);
#endif

/* This is the system's main function (which may or may not be called "main")
   - do general system-dependent initialization
   - call erl_start() to parse arguments and do other init
*/

static erts_smp_atomic_t sys_misc_mem_sz;

HMODULE beam_module = NULL;

void erl_sys_init();

void erl_sys_args(int* argc, char** argv);

int nohup;
#ifndef __GNUC__
void erts_sys_invalid_parameter_handler(const wchar_t * expression,
                                        const wchar_t * function, 
                                        const wchar_t * file, 
                                        unsigned int line,
                                        uintptr_t pReserved
                                        )
{
#ifdef DEBUG
    fprintf(stderr,
	    "Debug: Invalid parameter\"%ls\" "
	    "(detected in \"%ls\" [%ls:%d]) \n", 
	    (expression) ? expression : L"(unknown)",
	    (function) ? function : L"(unknown)",
	    (file) ? file : L"(unknown)",
	    line);
#endif
    return;
}
#endif

void sys_primitive_init(HMODULE beam)
{
#ifndef __GNUC__
    /* Initialize this module handle (the beam.dll module handle) and 
       take care of the standard library's aggressive invalid parameter 
       handling... */
    _set_invalid_parameter_handler(&erts_sys_invalid_parameter_handler);
#endif
    beam_module = (HMODULE) beam;
}

Uint
erts_sys_misc_mem_sz(void)
{
    Uint res = (Uint) erts_check_io_size();
    res += (Uint) erts_smp_atomic_read(&sys_misc_mem_sz);
    return res;
}

/*
 * Reset the terminal to the original settings on exit
 */
void sys_tty_reset(int exit_code)
{
    if (exit_code > 0)
	ConWaitForExit();
    else
	ConNormalExit();
}

void erl_sys_args(int* argc, char** argv)
{
    char *event_name;
    nohup = get_and_remove_option(argc, argv, "-nohup");

#ifdef DEBUG
    /*
     * Start a debug console if -console option given.
     */

    if (get_and_remove_option(argc, argv, "-console")) {
	debug_console();
    }
#endif

    if (nohup && (event_name = get_and_remove_option2(argc, argv, 
						      "-service_event"))) {
	if ((erts_service_event = 
	     OpenEvent(EVENT_ALL_ACCESS,FALSE,event_name)) == NULL) {
	    erts_fprintf(stderr,
			 "Warning: could not open service event: %s\r\n", 
			 event_name);
	}	    
    } else {
	erts_service_event = NULL;
    }

#ifdef DEBUG
    /*
     * Given the "-threads" option, always use threads instead of
     * named pipes.
     */

    if (get_and_remove_option(argc, argv, "-threads")) {
	use_named_pipes = FALSE;
    }
#endif
}

void
erts_sys_prepare_crash_dump(void)
{
    /* Windows - free file descriptors are hopefully available */
    return;
}

static void
init_console()
{
    char* mode = erts_read_env("ERL_CONSOLE_MODE");

    if (!mode || strcmp(mode, "window") == 0) {
	win_console = TRUE;
	ConInit();
	/*nohup = 0;*/
    } else if (strncmp(mode, "tty:", 4) == 0) {
	if (mode[5] == 'c') {
	    setvbuf(stdout, NULL, _IONBF, 0);
	}
	if (mode[6] == 'c') {
	    setvbuf(stderr, NULL, _IONBF, 0);
	}
    }

    erts_free_read_env(mode);
}

int sys_max_files() 
{
    return max_files;
}

/*
 * Looks for the given option in the argv vector.  If it is found,
 * it will be removed from the argv vector.
 *
 * If the return value indicates that the option was found and removed,
 * it is the responsibility of the caller to decrement the value of argc.
 *
 * Returns: 0 if the option wasn't found, 1 if it was found
 */

static int
get_and_remove_option(argc, argv, option)
    int* argc;			/* Number of arguments. */
    char* argv[];		/* The argument vector. */
    const char* option;		/* Option to search for and remove. */
{
    int i;

    for (i = 1; i < *argc; i++) {
	if (strcmp(argv[i], option) == 0) {
	    (*argc)--;
	    while (i < *argc) {
		argv[i] = argv[i+1];
		i++;
	    }
	    argv[i] = NULL;
	    return 1;
	}
    }
    return 0;
}

static char *get_and_remove_option2(int *argc, char **argv, 
				    const char *option)
{
    char *ret;
    int i;

    for (i = 1; i < *argc; i++) {
	if (strcmp(argv[i], option) == 0) {
	    if (i+1 < *argc) {
		ret = argv[i+1];
		(*argc) -= 2;
		while (i < *argc) {
		    argv[i] = argv[i+2];
		    i++;
		}
		argv[i] = NULL;
		return ret;
	    }
	}
    }
    return NULL;
}
    

/************************** OS info *******************************/

/* Used by erlang:info/1. */
/* (This code was formerly in drv.XXX/XXX_os_drv.c) */

char os_type[] = "win32";

void
os_flavor(namebuf, size)
char* namebuf;			/* Where to return the name. */
unsigned size;			/* Size of name buffer. */
{
    switch (int_os_version.dwPlatformId) {
    case VER_PLATFORM_WIN32_WINDOWS:
	strcpy(namebuf, "windows");
	break;
    case VER_PLATFORM_WIN32_NT:
	strcpy(namebuf, "nt");
	break;
    default:			/* Can't happen. */
	strcpy(namebuf, "unknown");
	break;
    }
}

void
os_version(pMajor, pMinor, pBuild)
int* pMajor;			/* Pointer to major version. */
int* pMinor;			/* Pointer to minor version. */
int* pBuild;			/* Pointer to build number. */
{
  *pMajor = int_os_version.dwMajorVersion;
  *pMinor = int_os_version.dwMinorVersion;
  *pBuild = int_os_version.dwBuildNumber;
}

/************************** Port I/O *******************************/

/* I. Common stuff */

/* II. The spawn/fd/vanilla drivers */

/*
 * Definitions for driver flags.
 */

#define DF_OVR_READY	1	/* Overlapped result is ready. */
#define DF_EXIT_THREAD	2	/* The thread should exit. */
#define DF_XLAT_CR	4	/* The thread should translate CRs. */
#define DF_DROP_IF_INVH 8       /* Drop packages instead of crash if
				   invalid handle (stderr) */

#define OV_BUFFER_PTR(dp) ((LPVOID) ((dp)->ov.Internal))
#define OV_NUM_TO_READ(dp) ((dp)->ov.InternalHigh)

/*
 * This data is used to make overlapped I/O operations work on both
 * Windows NT (using true overlapped I/O) and Windows 95 (using threads).
 */

typedef struct async_io {
  unsigned flags;		/* Driver flags, definitions found above. */
  HANDLE thread;		/* If -1, overlapped I/O is used (Windows NT).
				 * Otherwise, it is the handle of the thread used
				 * for simulating overlapped I/O (Windows 95 and
				 * the console for Windows NT).
				 */
  HANDLE fd;			/* Handle for file or pipe. */
#ifdef ERTS_SMP
  int async_io_active;          /* if true, a close of the file will signal the event in ov */
#endif
  OVERLAPPED ov;		/* Control structure for overlapped reading.
				 * When overlapped reading is simulated with
				 * a thread, the fields are used as follows:
				 *   ov.Internal - Read buffer.
				 *   ov.InternalHigh - Number of bytes to read.
				 * See macros above.
				 */
  HANDLE ioAllowed;		/* The thread will wait for this event
				 * before starting a new read or write.
				 */
  DWORD pendingError;		/* Used to delay presentating an error to Erlang
				 * until the check_io function is entered.
				 */
  DWORD bytesTransferred;	/* Bytes read or write in the last operation.
				 * Valid only when DF_OVR_READY is set.
				 */
} AsyncIo;


/*
 * Input thread for fd_driver (if fd_driver is running).
 */
static AsyncIo* fd_driver_input = NULL;
static BOOL (WINAPI *fpSetHandleInformation)(HANDLE,DWORD,DWORD);

/*
 * This data is used by the spawn and vanilla drivers.
 * There will be one entry for each port, even if the input
 * and output HANDLES are different.  Since handles are not
 * guaranteed to be small numbers in Win32, we cannot index
 * with them.  I.e. the index for each entry is not equal to
 * none of the file handles.
 */

typedef struct driver_data {
    int totalNeeded;		/* Total number of bytes needed to fill
				 * up the packet header or packet. */
    int bytesInBuffer;		/* Number of bytes read so far in
				 * the input buffer.
				 */
    int inBufSize;		/* Size of input buffer. */
    byte *inbuf;		/* Buffer to use for overlapped read. */
    int outBufSize;		/* Size of output buffer. */
    byte *outbuf;		/* Buffer to use for overlapped write. */
    ErlDrvPort port_num;		/* The port number. */
    int packet_bytes;		/* 0: continous stream, 1, 2, or 4: the number
				 * of bytes in the packet header.
				 */
    HANDLE port_pid;		/* PID of the port process. */
    AsyncIo in;			/* Control block for overlapped reading. */
    AsyncIo out;		/* Control block for overlapped writing. */
    int report_exit;            /* Do report exit status for the port */
} DriverData;

static DriverData* driver_data;	/* Pointer to array of driver data. */

/* Driver interfaces */
static ErlDrvData spawn_start(ErlDrvPort, char*, SysDriverOpts*);
static ErlDrvData fd_start(ErlDrvPort, char*, SysDriverOpts*);
static ErlDrvData vanilla_start(ErlDrvPort, char*, SysDriverOpts*);
static int spawn_init(void);
static int fd_init(void);
static void fd_stop(ErlDrvData);
static void stop(ErlDrvData);
static void output(ErlDrvData, char*, int);
static void ready_input(ErlDrvData, ErlDrvEvent);
static void ready_output(ErlDrvData, ErlDrvEvent);
static void stop_select(ErlDrvEvent, void*);

struct erl_drv_entry spawn_driver_entry = {
    spawn_init,
    spawn_start,
    stop,
    output,
    ready_input,
    ready_output,
    "spawn",
    NULL, /* finish */
    NULL, /* handle */
    NULL, /* control */
    NULL, /* timeout */
    NULL, /* outputv */
    NULL, /* ready_async */
    NULL, /* flush */
    NULL, /* call */
    NULL, /* event */
    ERL_DRV_EXTENDED_MARKER,
    ERL_DRV_EXTENDED_MAJOR_VERSION,
    ERL_DRV_EXTENDED_MINOR_VERSION,
    0,	/* ERL_DRV_FLAGs */
    NULL,
    NULL, /* process_exit */
    stop_select
};

#ifdef HARD_POLL_DEBUG
extern void poll_debug_set_active_fd(ErtsSysFdType fd);
extern void poll_debug_read_begin(ErtsSysFdType fd);
extern void poll_debug_read_done(ErtsSysFdType fd, int bytes);
extern void poll_debug_async_initialized(ErtsSysFdType fd);
extern void poll_debug_async_immediate(ErtsSysFdType fd, int bytes);
extern void poll_debug_write_begin(ErtsSysFdType fd);
extern void poll_debug_write_done(ErtsSysFdType fd, int bytes);
#endif

extern int null_func(void);

struct erl_drv_entry fd_driver_entry = {
    fd_init,
    fd_start,
    fd_stop,
    output,
    ready_input,
    ready_output,
    "fd",
    NULL, /* finish */
    NULL, /* handle */
    NULL, /* control */
    NULL, /* timeout */
    NULL, /* outputv */
    NULL, /* ready_async */
    NULL, /* flush */
    NULL, /* call */
    NULL, /* event */
    ERL_DRV_EXTENDED_MARKER,
    ERL_DRV_EXTENDED_MAJOR_VERSION,
    ERL_DRV_EXTENDED_MINOR_VERSION,
    0,	/* ERL_DRV_FLAGs */
    NULL,
    NULL, /* process_exit */
    stop_select
};

struct erl_drv_entry vanilla_driver_entry = {
    null_func,
    vanilla_start,
    stop,
    output,
    ready_input,
    ready_output,
    "vanilla",
    NULL, /* finish */
    NULL, /* handle */
    NULL, /* control */
    NULL, /* timeout */
    NULL, /* outputv */
    NULL, /* ready_async */
    NULL, /* flush */
    NULL, /* call */
    NULL, /* event */
    ERL_DRV_EXTENDED_MARKER,
    ERL_DRV_EXTENDED_MAJOR_VERSION,
    ERL_DRV_EXTENDED_MINOR_VERSION,
    0,	/* ERL_DRV_FLAGs */
    NULL,
    NULL, /* process_exit */
    stop_select
};

#if defined(USE_THREADS) && !defined(ERTS_SMP)

static int  async_drv_init(void);
static ErlDrvData async_drv_start(ErlDrvPort, char*, SysDriverOpts*);
static void async_drv_stop(ErlDrvData);
static void async_drv_input(ErlDrvData, ErlDrvEvent);

/* INTERNAL use only */

void null_output(ErlDrvData drv_data, char* buf, int len)
{
}

void null_ready_output(ErlDrvData drv_data, ErlDrvEvent event)
{
}

struct erl_drv_entry async_driver_entry = {
    async_drv_init,
    async_drv_start,
    async_drv_stop,
    null_output,
    async_drv_input,
    null_ready_output,
    "async",
    NULL, /* finish */
    NULL, /* handle */
    NULL, /* control */
    NULL, /* timeout */
    NULL, /* outputv */
    NULL, /* ready_async */
    NULL, /* flush */
    NULL, /* call */
    NULL, /* event */
    ERL_DRV_EXTENDED_MARKER,
    ERL_DRV_EXTENDED_MAJOR_VERSION,
    ERL_DRV_EXTENDED_MINOR_VERSION,
    0,	/* ERL_DRV_FLAGs */
    NULL,
    NULL, /* process_exit */
    stop_select
};

#endif

/*
 * Initialises a DriverData structure.
 *
 * Results: Returns a pointer to a DriverData structure, or NULL
 * if the initialsation failed.
 */

static DriverData*
new_driver_data(port_num, packet_bytes, wait_objs_required, use_threads)
    int port_num;		/* The port number. */
    int packet_bytes;		/* Number of bytes in header. */
    int wait_objs_required;	/* The number objects this port is going
				/* wait for (typically 1 or 2). */
    int use_threads;		/* TRUE if threads are intended to be used. */
{
    DriverData* dp;
    
    erts_smp_mtx_lock(&sys_driver_data_lock);

    DEBUGF(("new_driver_data(port_num %d, pb %d)\n",
	    port_num, packet_bytes));

    /*
     * We used to test first at all that there is enough room in the
     * array used by WaitForMultipleObjects(), but that is not necessary
     * any more, since driver_select() can't fail.
     */

    /*
     * Search for a free slot.
     */

    for (dp = driver_data; dp < driver_data+max_files; dp++) {
	if (dp->port_num == PORT_FREE) {
	    dp->bytesInBuffer = 0;
	    dp->totalNeeded = packet_bytes;
	    dp->inBufSize = PORT_BUFSIZ;
	    dp->inbuf = DRV_BUF_ALLOC(dp->inBufSize);
	    if (dp->inbuf == NULL) {
		erts_smp_mtx_unlock(&sys_driver_data_lock);
		return NULL;
	    }
	    erts_smp_atomic_add(&sys_misc_mem_sz, dp->inBufSize);
	    dp->outBufSize = 0;
	    dp->outbuf = NULL;
	    dp->port_num = port_num;
	    dp->packet_bytes = packet_bytes;
	    dp->port_pid = INVALID_HANDLE_VALUE;
	    if (init_async_io(&dp->in, use_threads) == -1)
		break;
	    if (init_async_io(&dp->out, use_threads) == -1)
		break;
	    erts_smp_mtx_unlock(&sys_driver_data_lock);
	    return dp;
	}
    }

    /*
     * Error or no free driver data.
     */

    if (dp < driver_data+max_files) {
	release_async_io(&dp->in, dp->port_num);
	release_async_io(&dp->out, dp->port_num);
    }
    erts_smp_mtx_unlock(&sys_driver_data_lock);
    return NULL;
}

static void
release_driver_data(DriverData* dp)
{
    erts_smp_mtx_lock(&sys_driver_data_lock);

#ifdef ERTS_SMP
    if (fpCancelIoEx != NULL) {
	if (dp->in.thread == (HANDLE) -1 && dp->in.fd != INVALID_HANDLE_VALUE) {
	    (*fpCancelIoEx)(dp->in.fd, NULL);
	}
	if (dp->out.thread == (HANDLE) -1 && dp->out.fd != INVALID_HANDLE_VALUE) {
	    (*fpCancelIoEx)(dp->out.fd, NULL);
	}
    }
    else {
	/* This is a workaround for the fact that CancelIo cant cancel
	   requests issued by another thread and that we cant use
	   CancelIoEx as that's only availabele in Vista etc.
	   R14: Avoid scheduler deadlock by only wait for 10ms, and then spawn
	    a thread that will keep waiting in in order to close handles. */
	HANDLE handles[2];
	int i = 0;
	int timeout = 10;
	if(dp->in.async_io_active && dp->in.fd != INVALID_HANDLE_VALUE) {
	    CloseHandle(dp->in.fd);
	    dp->in.fd = INVALID_HANDLE_VALUE;
	    DEBUGF(("Waiting for the in event thingie"));
	    if (WaitForSingleObject(dp->in.ov.hEvent,timeout) == WAIT_TIMEOUT) {
		handles[i++] = dp->in.ov.hEvent;
		dp->in.ov.hEvent = NULL;
		timeout = 0;
	    }
	    DEBUGF(("...done\n"));
	}
	if(dp->out.async_io_active && dp->out.fd != INVALID_HANDLE_VALUE) {
	    CloseHandle(dp->out.fd);
	    dp->out.fd = INVALID_HANDLE_VALUE;
	    DEBUGF(("Waiting for the out event thingie"));
	    if (WaitForSingleObject(dp->out.ov.hEvent,timeout) == WAIT_TIMEOUT) {
		handles[i++] = dp->out.ov.hEvent;
		dp->out.ov.hEvent = NULL;
	    }
	    DEBUGF(("...done\n"));
	}
	if (i > 0) {
	    close_active_handles(dp->port_num, handles, i);
	}
    }
#else
	if (dp->in.thread == (HANDLE) -1 && dp->in.fd != INVALID_HANDLE_VALUE) {
	     CancelIo(dp->in.fd); 
	}
	if (dp->out.thread == (HANDLE) -1 && dp->out.fd != INVALID_HANDLE_VALUE) {
	    CancelIo(dp->out.fd); 
	}
#endif

    if (dp->inbuf != NULL) {
	ASSERT(erts_smp_atomic_read(&sys_misc_mem_sz) >= dp->inBufSize);
	erts_smp_atomic_add(&sys_misc_mem_sz, -1*dp->inBufSize);
	DRV_BUF_FREE(dp->inbuf);
	dp->inBufSize = 0;
	dp->inbuf = NULL;
    }
    ASSERT(dp->inBufSize == 0);

    if (dp->outbuf != NULL) {
	ASSERT(erts_smp_atomic_read(&sys_misc_mem_sz) >= dp->outBufSize);
	erts_smp_atomic_add(&sys_misc_mem_sz, -1*dp->outBufSize);
	DRV_BUF_FREE(dp->outbuf);
	dp->outBufSize = 0;
	dp->outbuf = NULL;
    }
    ASSERT(dp->outBufSize == 0);

    if (dp->port_pid != INVALID_HANDLE_VALUE) {
	CloseHandle(dp->port_pid);
	dp->port_pid = INVALID_HANDLE_VALUE;
    }

    release_async_io(&dp->in, dp->port_num);
    release_async_io(&dp->out, dp->port_num);

    /*
     * This must be last, because this function might be executed from
     * the exit thread.
     */

    dp->port_num = PORT_FREE;
    erts_smp_mtx_unlock(&sys_driver_data_lock);
}

#ifdef ERTS_SMP

struct handles_to_be_closed
{
    int cnt;
    HANDLE handles[2];
};

static void close_active_handles(ErlDrvPort port_num, const HANDLE* handles, int cnt)
{
    DWORD tid;
    HANDLE thread;
    int i;
    struct handles_to_be_closed* htbc = erts_alloc(ERTS_ALC_T_DRV_TAB,
						   sizeof(struct handles_to_be_closed));
    htbc->cnt = cnt;
    for (i=0; i < cnt; ++i) {
	htbc->handles[i] = handles[i];
	(void) driver_select(port_num, (ErlDrvEvent)handles[i],
			     ERL_DRV_USE_NO_CALLBACK, 0);
    }
    thread = (HANDLE *) _beginthreadex(NULL, 0, threaded_handle_closer, htbc, 0, &tid);
    CloseHandle(thread);
}


static DWORD WINAPI
threaded_handle_closer(LPVOID param)
{
    struct handles_to_be_closed* htbc = (struct handles_to_be_closed*) param;
    int i;
    DEBUGF(("threaded_handle_closer waiting for %d handles\r\n",htbc->cnt));
    WaitForMultipleObjects(htbc->cnt, htbc->handles, TRUE, INFINITE);
    for (i=0; i < htbc->cnt; ++i) {
	CloseHandle(htbc->handles[i]);
    }
    erts_free(ERTS_ALC_T_DRV_TAB, htbc);
    DEBUGF(("threaded_handle_closer terminating\r\n"));
    return 0;
}
#endif /* ERTS_SMP */

/*
 * Stores input and output file descriptors in the DriverData structure,
 * and calls driver_select().
 *
 * This function fortunately can't fail!
 */

static ErlDrvData
set_driver_data(dp, ifd, ofd, read_write, report_exit)
    DriverData* dp;
    HANDLE ifd;
    HANDLE ofd;
    int read_write;
    int report_exit;
{
    int index = dp - driver_data;
    int result;

    dp->in.fd = ifd;
    dp->out.fd = ofd;
    dp->report_exit = report_exit;

    if (read_write & DO_READ) {
	result = driver_select(dp->port_num, (ErlDrvEvent)dp->in.ov.hEvent,
			       ERL_DRV_READ|ERL_DRV_USE, 1);
	ASSERT(result != -1);
	async_read_file(&dp->in, dp->inbuf, dp->inBufSize);
    }

    if (read_write & DO_WRITE) {
	result = driver_select(dp->port_num, (ErlDrvEvent)dp->out.ov.hEvent,
			       ERL_DRV_WRITE|ERL_DRV_USE, 1);
	ASSERT(result != -1);
    }
    return (ErlDrvData)index;
}

/*
 * Initialises an AsyncIo structure.
 */

static int
init_async_io(AsyncIo* aio, int use_threads)
{
    aio->flags = 0;
    aio->thread = (HANDLE) -1;
    aio->fd = INVALID_HANDLE_VALUE;
    aio->ov.hEvent = NULL;
    aio->ov.Offset = 0L;
    aio->ov.OffsetHigh = 0L;
    aio->ioAllowed = NULL;
    aio->pendingError = 0;
    aio->bytesTransferred = 0;
#ifdef ERTS_SMP
    aio->async_io_active = 0;
#endif
    aio->ov.hEvent = CreateManualEvent(FALSE);
    if (aio->ov.hEvent == NULL)
	return -1;
    if (use_threads) {
	aio->ioAllowed = CreateAutoEvent(FALSE);
	if (aio->ioAllowed == NULL)
	    return -1;
    }
    return 0;
}

/*
 * Releases everything allocated in an AsyncIo structure.
 */  

static void
release_async_io(AsyncIo* aio, ErlDrvPort port_num)
{
    aio->flags = 0;

    if (aio->thread != (HANDLE) -1)
	CloseHandle(aio->thread);
    aio->thread = (HANDLE) -1;

    if (aio->fd != INVALID_HANDLE_VALUE)
	CloseHandle(aio->fd);
    aio->fd = INVALID_HANDLE_VALUE;

    if (aio->ov.hEvent != NULL) {
	(void) driver_select(port_num,
			     (ErlDrvEvent)aio->ov.hEvent,
			     ERL_DRV_USE, 0);
	/* was CloseHandle(aio->ov.hEvent); */
    }

    aio->ov.hEvent = NULL;

    if (aio->ioAllowed != NULL)
	CloseHandle(aio->ioAllowed);
    aio->ioAllowed = NULL;
}

/* ----------------------------------------------------------------------
 * async_read_file --
 *	Initiaties an asynchronous file read, or simulates that using
 *	the thread associated with this driver data.  To get the results,
 *	call get_overlapped_result().
 *
 * Results:
 *	None.
 * ----------------------------------------------------------------------
 */

static void
async_read_file(aio, buf, numToRead)
    AsyncIo* aio;		/* Pointer to driver data. */
    LPVOID buf;			/* Pointer to buffer to receive data. */
    DWORD numToRead;		/* Number of bytes to read. */
{
    aio->pendingError = NO_ERROR;
#ifdef HARD_POLL_DEBUG
    poll_debug_async_initialized(aio->ov.hEvent);
#endif
    if (aio->thread != (HANDLE) -1) {
	DEBUGF(("async_read_file: signaling thread 0x%x, event 0x%x\n",
		aio->thread, aio->ioAllowed));
	OV_BUFFER_PTR(aio) = buf;
	OV_NUM_TO_READ(aio) = numToRead;
	ResetEvent(aio->ov.hEvent);
	SetEvent(aio->ioAllowed);
    } else {
#ifdef ERTS_SMP
	aio->async_io_active = 1; /* Will get 0 when the event actually happened */
#endif
	if (ReadFile(aio->fd, buf, numToRead,
		     &aio->bytesTransferred, &aio->ov)) {
	    DEBUGF(("async_read_file: ReadFile() suceeded: %d bytes\n",
		    aio->bytesTransferred));
#ifdef HARD_POLL_DEBUG
	    poll_debug_async_immediate(aio->ov.hEvent, aio->bytesTransferred);
#endif
	    aio->flags |= DF_OVR_READY;
	    SetEvent(aio->ov.hEvent);
	} else {
	    DWORD error = GetLastError();
	    if (error != ERROR_IO_PENDING) {
#ifdef HARD_POLL_DEBUG
		poll_debug_async_immediate(aio->ov.hEvent, 0);
#endif
		aio->pendingError = error;
		SetEvent(aio->ov.hEvent);
	    }
	    DEBUGF(("async_read_file: ReadFile() -> %s\n", win32_errorstr(error)));
	}
    }
}

/* ----------------------------------------------------------------------
 * async_write_file --
 *	Initiaties an asynchronous file write, or simulates that using
 *	the output thread associated with this driver data. 
 *	To get the results, call get_overlapped_result().
 *
 * Results:
 *	None.
 * ----------------------------------------------------------------------
 */
static int
async_write_file(aio, buf, numToWrite)
    AsyncIo* aio;		/* Pointer to async control block. */
    LPVOID buf;			/* Pointer to buffer with data to write. */
    DWORD numToWrite;		/* Number of bytes to write. */
{
    aio->pendingError = NO_ERROR;
    if (aio->thread != (HANDLE) -1) {
	DEBUGF(("async_write_file: signaling thread 0x%x, event 0x%x\n",
		aio->thread, aio->ioAllowed));
	OV_BUFFER_PTR(aio) = buf;
	OV_NUM_TO_READ(aio) = numToWrite;
	ResetEvent(aio->ov.hEvent);
	SetEvent(aio->ioAllowed);
    } else {
#ifdef ERTS_SMP
	aio->async_io_active = 1; /* Will get 0 when the event actually happened */
#endif
	if (WriteFile(aio->fd, buf, numToWrite,
		      &aio->bytesTransferred, &aio->ov)) {
	    DEBUGF(("async_write_file: WriteFile() suceeded: %d bytes\n",
		    aio->bytesTransferred));
#ifdef ERTS_SMP
	    aio->async_io_active = 0; /* The event will not be signalled */
#endif
	    ResetEvent(aio->ov.hEvent);
	    return TRUE;
	} else {
	    DWORD error = GetLastError();
	    if (error != ERROR_IO_PENDING) {
		aio->pendingError = error;
		SetEvent(aio->ov.hEvent);
	    }
	    DEBUGF(("async_write_file: WriteFile() -> %s\n", win32_errorstr(error)));
	}
    }
    return FALSE;
}

/* ----------------------------------------------------------------------
 * get_overlapped_result --
 *
 * Results:
 *	Returns the error code for the overlapped result, or NO_ERROR
 *	if no error.
 * ----------------------------------------------------------------------
 */
static int
get_overlapped_result(aio, pBytesRead, wait)
    AsyncIo* aio;		/* Pointer to async control block. */
    LPDWORD pBytesRead;		/* Where to place the number of bytes
				 * transferred.
				 */
    BOOL wait;			/* If true, wait until result is ready. */
{
    DWORD error = NO_ERROR;	/* Error status from last function. */

    if (aio->thread != (HANDLE) -1) {

	/*
	 * Simulate overlapped io with a thread.
	 */
	DEBUGF(("get_overlapped_result: about to wait for event 0x%x\n",
		aio->ov.hEvent));
	error = WaitForSingleObject(aio->ov.hEvent, wait ? INFINITE : 0);
	switch (error) {
	case WAIT_OBJECT_0:
	    error = aio->pendingError;
	    aio->pendingError = NO_ERROR;
	    *pBytesRead = aio->bytesTransferred;
	    ResetEvent(aio->ov.hEvent);
	    DEBUGF(("get_overlapped_result -> %s\n",
		    win32_errorstr(error)));
	    return error;
	case WAIT_TIMEOUT:
	    DEBUGF(("get_overlapped_result -> %s\n",
		    ERROR_IO_INCOMPLETE));
	    return ERROR_IO_INCOMPLETE;
	case WAIT_FAILED:		/* XXX: Shouldn't happen? */
	    error = GetLastError();
	    DEBUGF(("get_overlapped_result (WAIT_FAILED) -> %s\n",
		    win32_errorstr(error)));
	    return error;
	}
    } else if (aio->pendingError != NO_ERROR) { /* Pending error. */
	error = aio->pendingError;
	aio->pendingError = NO_ERROR;
	ResetEvent(aio->ov.hEvent);
	DEBUGF(("get_overlapped_result: pending error: %s\n",
		win32_errorstr(error)));
	return error;
    } else if (aio->flags & DF_OVR_READY) { /* Operation succeded. */
	aio->flags &= ~DF_OVR_READY;
	*pBytesRead = aio->bytesTransferred;
	ResetEvent(aio->ov.hEvent);
	DEBUGF(("get_overlapped_result: delayed success: %d bytes\n",
		aio->bytesTransferred));
    } else if (!GetOverlappedResult(aio->fd, &aio->ov, pBytesRead, wait)) {
	error = GetLastError();
	ResetEvent(aio->ov.hEvent);
	DEBUGF(("get_overlapped_result: error: %s\n", win32_errorstr(error)));
	return error;
    } else {			/* Success. */
	DEBUGF(("get_overlapped_result: success\n"));
	ResetEvent(aio->ov.hEvent);
    }
    return NO_ERROR;
}
  
static int
fd_init(void)
{
    char kernel_dll_name[] = "kernel32";
    HMODULE module;
    module = GetModuleHandle(kernel_dll_name);
    fpSetHandleInformation = (module != NULL) ? 
	(BOOL (WINAPI *)(HANDLE,DWORD,DWORD)) 
	GetProcAddress(module,"SetHandleInformation") : 
	NULL;

    return 0;
}
static int
spawn_init()
{
    int i;
#ifdef ERTS_SMP
    HMODULE module = GetModuleHandle("kernel32");
    fpCancelIoEx = (module != NULL) ?
	(BOOL (WINAPI *)(HANDLE,LPOVERLAPPED))
      GetProcAddress(module,"CancelIoEx") : NULL;
    DEBUGF(("fpCancelIoEx = %p\r\n", fpCancelIoEx));
#endif
    driver_data = (struct driver_data *)
	erts_alloc(ERTS_ALC_T_DRV_TAB, max_files * sizeof(struct driver_data));
    erts_smp_atomic_add(&sys_misc_mem_sz, max_files*sizeof(struct driver_data));
    for (i = 0; i < max_files; i++)
	driver_data[i].port_num = PORT_FREE;

    return 0;
}

static ErlDrvData
spawn_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
{
    HANDLE hToChild = INVALID_HANDLE_VALUE; /* Write handle to child. */
    HANDLE hFromChild = INVALID_HANDLE_VALUE; /* Read handle from child. */
    HANDLE hChildStdin = INVALID_HANDLE_VALUE;		/* Child's stdin. */
    HANDLE hChildStdout = INVALID_HANDLE_VALUE;	/* Child's stout. */
    HANDLE hChildStderr = INVALID_HANDLE_VALUE;	/* Child's sterr. */
    int close_child_stderr = 0;
    DriverData* dp;		/* Pointer to driver data. */
    ErlDrvData retval = ERL_DRV_ERROR_GENERAL; /* Return value. */
    int ok;
    int neededSelects = 0;
    SECURITY_ATTRIBUTES sa = {sizeof(SECURITY_ATTRIBUTES), NULL, TRUE};
    char* envir = opts->envir;
    int errno_return = -1;
    
    if (opts->read_write & DO_READ)
	neededSelects++;
    if (opts->read_write & DO_WRITE)
	neededSelects++;

    if ((dp = new_driver_data(port_num, opts->packet_bytes, neededSelects,
			      !use_named_pipes)) == NULL)
	return ERL_DRV_ERROR_GENERAL;

    /*
     * Create two pipes to communicate with the port program.
     */

    if (opts->read_write & DO_READ) {
	if (!create_pipe(&hFromChild, &hChildStdout, FALSE, 
			 opts->overlapped_io))
	    goto error;
    } else {
	hChildStdout = CreateFile("nul", GENERIC_WRITE, 0,
				  &sa, OPEN_EXISTING,
				  FILE_ATTRIBUTE_NORMAL, NULL);
	DEBUGF(("Created nul file for hChildStdout = %d\n",hChildStdout));
    }
    if (opts->read_write & DO_WRITE) {
	if (!create_pipe(&hChildStdin, &hToChild, TRUE, opts->overlapped_io)) {
	    CloseHandle(hFromChild);
	    hFromChild = INVALID_HANDLE_VALUE;
	    CloseHandle(hChildStdout);
	    goto error;
	}
    } else {
	hChildStdin = CreateFile("nul", GENERIC_READ, 0,
				 &sa, OPEN_EXISTING,
				 FILE_ATTRIBUTE_NORMAL, NULL);
	DEBUGF(("Created nul file for hChildStdin = %d\n",hChildStdin));
    }	

    /*
     * Make sure that standard error is valid handle, because a Command Prompt
     * window not work properly otherwise.  We leave standard error alone if
     * it is okay and no redirection was specified.
     */
    hChildStderr = GetStdHandle(STD_ERROR_HANDLE);
    if (opts->redir_stderr) {
	hChildStderr = hChildStdout;
    } else if (hChildStderr == INVALID_HANDLE_VALUE || hChildStderr == 0) {
	hChildStderr = CreateFile("nul", GENERIC_WRITE, 0, &sa, OPEN_EXISTING,
				  FILE_ATTRIBUTE_NORMAL, NULL);
	close_child_stderr = 1;
    }
    if (fpSetHandleInformation != NULL) {
	(*fpSetHandleInformation)(hChildStderr, HANDLE_FLAG_INHERIT, 1);
    }
    /*
     * Spawn the port program.
     */

    DEBUGF(("Spawning \"%s\"\n", name));
    envir = win_build_environment(envir);
    ok = CreateChildProcess(name, 
			    hChildStdin, 
			    hChildStdout,
			    hChildStderr,
			    &dp->port_pid,
			    opts->hide_window,
			    (LPVOID) envir,
			    (LPTSTR) opts->wd,
			    opts->spawn_type,
			    opts->argv, 
			    &errno_return);
    CloseHandle(hChildStdin);
    CloseHandle(hChildStdout);
    if (close_child_stderr && hChildStderr != INVALID_HANDLE_VALUE &&
	hChildStderr != 0) {
	CloseHandle(hChildStderr);
    }
    if (envir != NULL) {
	erts_free(ERTS_ALC_T_ENVIRONMENT, envir);
    }

    if (!ok) {
	dp->port_pid = INVALID_HANDLE_VALUE;
	if (errno_return >= 0) {
	    retval = ERL_DRV_ERROR_ERRNO;
	} 
    } else {
	if (!use_named_pipes) {
	    if ((opts->read_write & DO_READ) &&
		!create_file_thread(&dp->in, DO_READ))
		goto error;
	    if ((opts->read_write & DO_WRITE) &&
		!create_file_thread(&dp->out, DO_WRITE)) {
		dp->in.flags = DF_EXIT_THREAD;
		SetEvent(dp->in.ioAllowed);
		WaitForSingleObject(dp->in.thread, INFINITE);
		dp->in.thread = (HANDLE) -1;
		goto error;
	    }
	}
#ifdef HARD_POLL_DEBUG
	if (strncmp(name,"inet_gethost",12) == 0) {
	    erts_printf("Debugging \"%s\"\n", name);
	    poll_debug_set_active_fd(dp->in.ov.hEvent);
	}
#endif
	retval = set_driver_data(dp, hFromChild, hToChild, opts->read_write,
				 opts->exit_status);
    }
    
    if (retval != ERL_DRV_ERROR_GENERAL && retval != ERL_DRV_ERROR_ERRNO)
	return retval;
    
 error:
    if (hFromChild != INVALID_HANDLE_VALUE)
	CloseHandle(hFromChild);
    if (hToChild != INVALID_HANDLE_VALUE)
	CloseHandle(hToChild);
    release_driver_data(dp);
    if (retval == ERL_DRV_ERROR_ERRNO) {
	errno = errno_return;
    }
    return retval;
}

static int
create_file_thread(AsyncIo* aio, int mode)
{
    DWORD tid;			/* Id for thread. */

    aio->thread = (HANDLE)
	_beginthreadex(NULL, 0, 
		       (mode & DO_WRITE) ? threaded_writer : threaded_reader,
		       aio, 0, &tid);

    return aio->thread != (HANDLE) -1;
}

/* 
 *  A helper function used by CreateChildProcess().
 *  Parses a command line with arguments and returns the length of the
 *  first part containing the program name.
 *  Example: input = "\"Program Files\"\\erl arg1 arg2"
 *  gives 19 as result.
 *  The length returned is equivalent with length(argv[0]) if the
 *  comman line should have been prepared by _setargv for the main function
*/
int parse_command(char* cmd){
#define NORMAL 2
#define STRING 1
#define STOP 0
    int i =0;
    int state = NORMAL;
    while (cmd[i]) {
	switch (cmd[i]) {
	case '"':
	    if (state == NORMAL) 
		state = STRING;
	    else
		state = NORMAL;
	    break;
	case '\\':
	    if ((state == STRING) && (cmd[i+1]=='"'))
		i++;
	    break;
	case ' ':
	    if (state == NORMAL)
		state = STOP;
	    break;
	default:
	    break;
	}
	if (state == STOP) {
	    return i;
	}
	i++;
    }
    return i;
}

BOOL need_quotes(char *str)
{
    int in_quote = 0;
    int backslashed = 0;
    int naked_space = 0;
    while (*str != '\0') {
	switch (*str) {
	case '\\' :
	    backslashed = !backslashed;
	    break;
	case '"':
	    if (backslashed) {
		backslashed=0;
	    } else {
		in_quote = !in_quote;
	    }
	    break;
	case ' ':
	    backslashed = 0;
	    if (!(backslashed || in_quote)) {
		naked_space++;
	    }
	    break;
	default:
	    backslashed = 0;
	}
	++str;
    }
    return (naked_space > 0);
}
	    
	    

/*
 *----------------------------------------------------------------------
 *
 * CreateChildProcess --
 *
 *	Create a child process that has pipes as its 
 *	standard input, output, and error.  The child process runs
 *	synchronously under Win32s and asynchronously under Windows NT
 *	and Windows 95, and runs with the same environment variables
 *	as the creating process.
 *
 *	The complete Windows search path is searched to find the specified 
 *	executable.  If an executable by the given name is not found, 
 *	automatically tries appending ".com", ".exe", and ".bat" to the 
 *	executable name.
 *
 * Results:
 *	The return value is FALSE if there was a problem creating the child process.  
 *      Otherwise, the return value is 0 and *phPid is
 *	filled with the process id of the child process.
 * 
 * Side effects:
 *	A process is created.
 *	
 *----------------------------------------------------------------------
 */

static BOOL
CreateChildProcess
(
 char *origcmd,  /* Command line for child process (including
		  * name of executable). Or whole executable if st is
		  * ERTS_SPAWN_EXECUTABLE
		  */
 HANDLE hStdin,  /* The standard input handle for child. */
 HANDLE hStdout, /* The standard output handle for child. */ 
 HANDLE hStderr, /* The standard error handle for child. */
 LPHANDLE phPid, /* Pointer to variable to received PID. */
 BOOL hide,      /* Hide the window unconditionally. */
 LPVOID env,     /* Environment for the child */
 LPTSTR wd,      /* Working dir for the child */
 unsigned st,    /* Flags for spawn, tells us how to interpret origcmd */
 char **argv,     /* Argument vector if given. */
 int *errno_return /* Place to put an errno in in case of failure */
 )
{ 
    PROCESS_INFORMATION piProcInfo = {0};
    STARTUPINFO siStartInfo = {0};
    BOOL ok = FALSE;
    int applType;
    /* Not to be changed for different types of executables */
    int staticCreateFlags = GetPriorityClass(GetCurrentProcess()); 
    int createFlags = DETACHED_PROCESS;
    char *newcmdline = NULL;
    char execPath[MAX_PATH];
    int cmdlength;
    char* thecommand;
    LPTSTR appname = NULL;
    HANDLE hProcess = GetCurrentProcess();
    
    *errno_return = -1;

    siStartInfo.cb = sizeof(STARTUPINFO); 
    siStartInfo.dwFlags = STARTF_USESTDHANDLES;
    siStartInfo.hStdInput = hStdin;
    siStartInfo.hStdOutput = hStdout;
    siStartInfo.hStdError = hStderr;


    if (st != ERTS_SPAWN_EXECUTABLE) {
	/*
	 * Parse out the program name from the command line (it can be quoted and
	 * contain spaces).
	 */
	newcmdline = erts_alloc(ERTS_ALC_T_TMP, 2048);
	cmdlength = parse_command(origcmd);
	thecommand = (char *) erts_alloc(ERTS_ALC_T_TMP, cmdlength+1);
	strncpy(thecommand, origcmd, cmdlength);
	thecommand[cmdlength] = '\0';
	DEBUGF(("spawn command: %s\n", thecommand));
    
	applType = ApplicationType(thecommand, execPath, TRUE, 
				   TRUE, errno_return);
	DEBUGF(("ApplicationType returned for (%s) is %d\n", thecommand, applType));
	erts_free(ERTS_ALC_T_TMP, (void *) thecommand);
	if (applType == APPL_NONE) {
	    erts_free(ERTS_ALC_T_TMP,newcmdline);
	    return FALSE;
	}
	newcmdline[0] = '\0'; 

	if (applType == APPL_DOS) {
	    /*
	     * Under NT, 16-bit DOS applications will not run unless they
	     * can be attached to a console.  Run the 16-bit program as
	     * a normal process inside of a hidden console application,
	     * and then run that hidden console as a detached process.
	     */
	    
	    siStartInfo.wShowWindow = SW_HIDE;
	    siStartInfo.dwFlags |= STARTF_USESHOWWINDOW;
	    createFlags = CREATE_NEW_CONSOLE;
	    strcat(newcmdline, "cmd.exe /c ");
	} else if (hide) {
	    DEBUGF(("hiding window\n"));
	    siStartInfo.wShowWindow = SW_HIDE;
	    siStartInfo.dwFlags |= STARTF_USESHOWWINDOW;
	    createFlags = 0;
	}

	strcat(newcmdline, execPath);
	strcat(newcmdline, origcmd+cmdlength);
    } else { /* ERTS_SPAWN_EXECUTABLE */
	int run_cmd = 0;
	applType = ApplicationType(origcmd, execPath, FALSE, FALSE, 
				   errno_return);
	if (applType == APPL_NONE) {
	    return FALSE;
	} 
	if (applType == APPL_DOS) {
		/*
		 * See comment above
		 */
		
		siStartInfo.wShowWindow = SW_HIDE;
		siStartInfo.dwFlags |= STARTF_USESHOWWINDOW;
		createFlags = CREATE_NEW_CONSOLE;
		run_cmd = 1;
	} else if (hide) {
		DEBUGF(("hiding window\n"));
		siStartInfo.wShowWindow = SW_HIDE;
		siStartInfo.dwFlags |= STARTF_USESHOWWINDOW;
		createFlags = 0;
	}
	if (run_cmd) {
	    char cmdPath[MAX_PATH];
	    int cmdType;
	    cmdType = ApplicationType("cmd.exe", cmdPath, TRUE, FALSE, errno_return);
	    if (cmdType == APPL_NONE || cmdType == APPL_DOS) {
		return FALSE;
	    }
	    appname = (char *) erts_alloc(ERTS_ALC_T_TMP, strlen(cmdPath)+1);
	    strcpy(appname,cmdPath);
	} else {
	    appname = (char *) erts_alloc(ERTS_ALC_T_TMP, strlen(execPath)+1);
	    strcpy(appname,execPath);
	}
	if (argv == NULL) {
	    BOOL orig_need_q = need_quotes(execPath);
	    char *ptr;
	    int ocl = strlen(execPath);
	    if (run_cmd) {
		newcmdline = (char *) erts_alloc(ERTS_ALC_T_TMP, 
						 ocl + ((orig_need_q) ? 3 : 1)
						 + 11);
		memcpy(newcmdline,"cmd.exe /c ",11);
		ptr = newcmdline + 11;
	    } else {
		newcmdline = (char *) erts_alloc(ERTS_ALC_T_TMP, 
						 ocl + ((orig_need_q) ? 3 : 1));
		ptr = newcmdline;
	    }
	    if (orig_need_q) {
		*ptr++ = '"';
	    }
	    memcpy(ptr,execPath,ocl);
	    ptr += ocl;
	    if (orig_need_q) {
		*ptr++ = '"';
	    }
	    *ptr = '\0';
	} else {
	    int sum = 1; /* '\0' */
	    char **ar = argv;
	    char *n;
	    char *save_arg0 = NULL;
	    if (argv[0] == erts_default_arg0 || run_cmd) {
		save_arg0 = argv[0];
		argv[0] = execPath;
	    }
	    if (run_cmd) {
		sum += 11; /* cmd.exe /c */
	    }
	    while (*ar != NULL) {
		sum += strlen(*ar);
		if (need_quotes(*ar)) {
		    sum += 2; /* quotes */
		}
		sum++; /* space */
		++ar;
	    }
	    ar = argv;
	    newcmdline = erts_alloc(ERTS_ALC_T_TMP, sum);
	    n = newcmdline;
	    if (run_cmd) {
		memcpy(n,"cmd.exe /c ",11);
		n += 11;
	    }
	    while (*ar != NULL) {
		int q = need_quotes(*ar);
		sum = strlen(*ar);
		if (q) {
		    *n++ = '"';
		}
		memcpy(n,*ar,sum);
		n += sum;
		if (q) {
		    *n++ = '"';
		}
		*n++ = ' ';
		++ar;
	    }
	    ASSERT(n > newcmdline);
	    *(n-1) = '\0';
	    if (save_arg0 != NULL) {
		argv[0] = save_arg0;
	    }
	}	    
	    
    }
    DEBUGF(("Creating child process: %s, createFlags = %d\n", newcmdline, createFlags));
    ok = CreateProcess(appname, 
		       newcmdline, 
		       NULL, 
		       NULL, 
		       TRUE, 
		       createFlags | staticCreateFlags, 
		       env, 
		       wd, 
		       &siStartInfo, 
		       &piProcInfo);

    if (newcmdline != NULL) {
	    erts_free(ERTS_ALC_T_TMP,newcmdline);
    }	
    if (appname != NULL) {
	    erts_free(ERTS_ALC_T_TMP,appname);
    }	
    if (!ok) {
	DEBUGF(("CreateProcess failed: %s\n", last_error()));
	if (*errno_return < 0) {
	    *errno_return = EACCES;
	}
	return FALSE;
    }
    CloseHandle(piProcInfo.hThread); /* Necessary to avoid resource leak. */
    *phPid = piProcInfo.hProcess;
    
    if (applType == APPL_DOS) {
	WaitForSingleObject(hProcess, 50);
    }
    
    /* 
     * When an application spawns a process repeatedly, a new thread 
     * instance will be created for each process but the previous 
     * instances may not be cleaned up.  This results in a significant 
     * virtual memory loss each time the process is spawned.  If there 
     * is a WaitForInputIdle() call between CreateProcess() and
     * CloseHandle(), the problem does not occur. PSS ID Number: Q124121
     */
    
    WaitForInputIdle(piProcInfo.hProcess, 5000);
    
    return ok;
}

/* 
 * Note, inheritRead == FALSE means "inhetitWrite", i e one of the
 * pipe ends is always expected to be inherited. The pipe end that should 
 * be inherited is opened without overlapped io flags, as the child program
 * would expect stdout not to demand overlapped I/O. 
 */
static int create_pipe(HANDLE *phRead, HANDLE *phWrite, BOOL inheritRead, BOOL overlapped_io)
{
    SECURITY_ATTRIBUTES sa = {sizeof(SECURITY_ATTRIBUTES), NULL, TRUE};
    char pipe_name[128];	/* Name of pipe. */
    Uint calls;

    /*
     * If we should't use named pipes, create anonmous pipes.
     */

    if (!use_named_pipes) {
	int success;
	HANDLE non_inherited;	/* Non-inherited copy of handle. */

	if (!CreatePipe(phRead, phWrite, &sa, 0)) {
	    DEBUGF(("Error creating anonyomous pipe: %s\n", last_error()));
	    return FALSE;
	}

	if (inheritRead) {
	    success = DuplicateHandle(GetCurrentProcess(), *phWrite,
				      GetCurrentProcess(), &non_inherited, 0,
				      FALSE, DUPLICATE_SAME_ACCESS);
	    CloseHandle(*phWrite);
	    *phWrite = non_inherited;
	} else {
	    success = DuplicateHandle(GetCurrentProcess(), *phRead,
				      GetCurrentProcess(), &non_inherited, 0,
				      FALSE, DUPLICATE_SAME_ACCESS);
	    CloseHandle(*phRead);
	    *phRead = non_inherited;
	}
	return success;
    }


    /*
     * Otherwise, create named pipes.
     */

    calls = (Uint) erts_smp_atomic_inctest(&pipe_creation_counter);
    sprintf(pipe_name, "\\\\.\\pipe\\erlang44_%d_%d",
	    getpid(), calls);

    DEBUGF(("Creating pipe %s\n", pipe_name));
    sa.bInheritHandle = inheritRead;
    if ((*phRead = CreateNamedPipe(pipe_name,
				   PIPE_ACCESS_INBOUND | 
				   ((inheritRead && !overlapped_io) ? 0 : FILE_FLAG_OVERLAPPED),
				   PIPE_TYPE_BYTE | PIPE_READMODE_BYTE,
				   1,
				   0,
				   0,
				   2000,
				   &sa)) == NULL) {
	DEBUGF(("Error creating pipe: %s\n", last_error()));
	return FALSE;
    }
  
    sa.bInheritHandle = !inheritRead;
    if ((*phWrite = CreateFile(pipe_name,
			       GENERIC_WRITE,
			       0, /* No sharing */
			       &sa,
			       OPEN_EXISTING,
			       FILE_ATTRIBUTE_NORMAL | 
			       ((inheritRead || overlapped_io) ? FILE_FLAG_OVERLAPPED : 0),
			       NULL)) == INVALID_HANDLE_VALUE) {
	CloseHandle(*phRead);
	DEBUGF(("Error opening other end of pipe: %s\n", last_error()));
	return FALSE;
    }
    return TRUE;
}




static int ApplicationType
(
 const char *originalName, /* Name of the application to find. */ 
 char fullPath[MAX_PATH],  /* Filled with complete path to 
			    * application. */
 BOOL search_in_path,      /* If we should search the system wide path */
 BOOL handle_quotes,       /* If we should handle quotes around executable */
 int *error_return         /* A place to put an error code */
 )
{
    int applType, i;
    HANDLE hFile;
    char *ext, *rest;
    char buf[2];
    DWORD read;
    IMAGE_DOS_HEADER header;
    static char extensions[][5] = {"", ".com", ".exe", ".bat"};
    int is_quoted;
    int len;

    /* Look for the program as an external program.  First try the name
     * as it is, then try adding .com, .exe, and .bat, in that order, to
     * the name, looking for an executable.
     * NOTE! that we does not support execution of .com programs on Windows NT
     * 
     *
     * Using the raw SearchPath() procedure doesn't do quite what is 
     * necessary.  If the name of the executable already contains a '.' 
     * character, it will not try appending the specified extension when
     * searching (in other words, SearchPath will not find the program 
     * "a.b.exe" if the arguments specified "a.b" and ".exe").   
     * So, first look for the file as it is named.  Then manually append 
     * the extensions, looking for a match.  (')
     */

    len = strlen(originalName);
    is_quoted = handle_quotes && len > 0 && originalName[0] == '"' && 
	originalName[len-1] == '"';

    applType = APPL_NONE;
    *error_return = ENOENT;
    for (i = 0; i < (int) (sizeof(extensions) / sizeof(extensions[0])); i++) {
	if(is_quoted) {
	   lstrcpyn(fullPath, originalName+1, MAX_PATH - 7); 
	   len = strlen(fullPath);
	   if(len > 0) {
	       fullPath[len-1] = '\0';
	   }
	} else {
	    lstrcpyn(fullPath, originalName, MAX_PATH - 5);
	}
	lstrcat(fullPath, extensions[i]);
	SearchPath((search_in_path) ? NULL : ".", fullPath, NULL, MAX_PATH, fullPath, &rest);

	/*
	 * Ignore matches on directories or data files, return if identified
	 * a known type.
	 */

	if (GetFileAttributes(fullPath) & FILE_ATTRIBUTE_DIRECTORY) {
	    continue;
	}

	ext = strrchr(fullPath, '.');
	if ((ext != NULL) && (strcmpi(ext, ".bat") == 0)) {
	    *error_return = EACCES;
	    applType = APPL_DOS;
	    break;
	}

	hFile = CreateFile(fullPath, GENERIC_READ, FILE_SHARE_READ, NULL, 
		OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
	if (hFile == INVALID_HANDLE_VALUE) {
	    continue;
	}

	*error_return = EACCES; /* If considered an error, 
				    it's an access error */
	header.e_magic = 0;
	ReadFile(hFile, (void *) &header, sizeof(header), &read, NULL);
	if (header.e_magic != IMAGE_DOS_SIGNATURE) {
	    /* 
	     * Doesn't have the magic number for relocatable executables.  If 
	     * filename ends with .com, assume it's a DOS application anyhow.
	     * Note that we didn't make this assumption at first, because some
	     * supposed .com files are really 32-bit executables with all the
	     * magic numbers and everything.  
	     */

	    CloseHandle(hFile);
	    if ((ext != NULL) && (strcmpi(ext, ".com") == 0)) {
		applType = APPL_DOS;
		break;
	    }
	    continue;
	}
	if (header.e_lfarlc != sizeof(header)) {
	    /* 
	     * All Windows 3.X and Win32 and some DOS programs have this value
	     * set here.  If it doesn't, assume that since it already had the 
	     * other magic number it was a DOS application.
	     */

	    CloseHandle(hFile);
	    applType = APPL_DOS;
	    break;
	}

	/* 
	 * The DWORD at header.e_lfanew points to yet another magic number.
	 */

	buf[0] = '\0';
	SetFilePointer(hFile, header.e_lfanew, NULL, FILE_BEGIN);
	ReadFile(hFile, (void *) buf, 2, &read, NULL);
	CloseHandle(hFile);

	if ((buf[0] == 'L') && (buf[1] == 'E')) {
	    applType = APPL_DOS;
	} else if ((buf[0] == 'N') && (buf[1] == 'E')) {
	    applType = APPL_WIN3X;
	} else if ((buf[0] == 'P') && (buf[1] == 'E')) {
	    applType = APPL_WIN32;
	} else {
	    continue;
	}
	break;
    }

    if (applType == APPL_NONE) {
	return APPL_NONE;
    }

    if ((applType == APPL_DOS) || (applType == APPL_WIN3X)) {
	/* 
	 * Replace long path name of executable with short path name for 
	 * 16-bit applications.  Otherwise the application may not be able
	 * to correctly parse its own command line to separate off the 
	 * application name from the arguments.
	 */

	GetShortPathName(fullPath, fullPath, MAX_PATH);
    }
    if (is_quoted) {
	/* restore quotes on quoted program name */
	len = strlen(fullPath);
	memmove(fullPath+1,fullPath,len);
	fullPath[0]='"';
	fullPath[len+1]='"';
	fullPath[len+2]='\0';
    }
    return applType;
}

/*
 * Thread function used to emulate overlapped reading.
 */

DWORD WINAPI
threaded_reader(LPVOID param)
{
    AsyncIo* aio = (AsyncIo *) param;
    HANDLE thread = GetCurrentThread();
    char* buf;
    DWORD numToRead;
  
    for (;;) {
	WaitForSingleObject(aio->ioAllowed, INFINITE);
	if (aio->flags & DF_EXIT_THREAD)
	    break;
	buf = OV_BUFFER_PTR(aio);
	numToRead = OV_NUM_TO_READ(aio);
	aio->pendingError = 0;
	if (!ReadFile(aio->fd, buf, numToRead, &aio->bytesTransferred, NULL))
	    aio->pendingError = GetLastError();
	else if (aio->flags & DF_XLAT_CR) {
	    char *s;
	    int n;
	    
	    n = aio->bytesTransferred;
	    for (s = buf; s < buf+n; s++) {
		if (*s == '\r') {
		    if (s < buf + n - 1 && s[1] == '\n') {
			memmove(s, s+1, (buf+n - s - 1));
			--n;
		    } else {
			*s = '\n';
		    }
		}
	    }
	    aio->bytesTransferred = n;
	}
	SetEvent(aio->ov.hEvent);
	if ((aio->flags & DF_XLAT_CR) == 0 && aio->bytesTransferred == 0) {
	    break;
	}
	if (aio->pendingError != NO_ERROR) {
	    break;
	}
	if (aio->flags & DF_EXIT_THREAD)
	    break;
    }
    return 0;
}

/*
 * Thread function used to emulate overlapped writing
 */

DWORD WINAPI
threaded_writer(LPVOID param)
{
    AsyncIo* aio = (AsyncIo *) param;
    HANDLE thread = GetCurrentThread();
    char* buf;
    DWORD numToWrite;
    int ok;
  
    for (;;) {
	WaitForSingleObject(aio->ioAllowed, INFINITE);
	if (aio->flags & DF_EXIT_THREAD)
	    break;
	buf = OV_BUFFER_PTR(aio);
	numToWrite = OV_NUM_TO_READ(aio);
	aio->pendingError = 0;
	ok = WriteFile(aio->fd, buf, numToWrite, &aio->bytesTransferred, NULL);
	if (!ok) {
	    aio->pendingError = GetLastError();
	    if (aio->pendingError == ERROR_INVALID_HANDLE && 
		aio->flags & DF_DROP_IF_INVH) {
		/* This is standard error and we'we got an 
		   invalid standard error FD (non-inheritable) from parent. 
		   Just drop the message and be happy. */
		aio->pendingError = 0;
		aio->bytesTransferred = numToWrite;
	    } else if (aio->pendingError == ERROR_NOT_ENOUGH_MEMORY) {
		/* This could be a console, which limits utput to 64kbytes, 
		   which might translate to less on a unicode system. 
		   Try 16k chunks and see if it works before giving up. */
		int done = 0;
		DWORD transferred;
		aio->pendingError = 0;
		aio->bytesTransferred = 0;
		ok = 1;
		while (ok && (numToWrite - done) > 0x4000) {
		    ok = WriteFile(aio->fd, buf + done, 0x4000, &transferred, NULL);
		    aio->bytesTransferred += transferred;
		    done += 0x4000;
		}
		if (ok && (numToWrite - done) > 0) {
		    ok = WriteFile(aio->fd, buf + done, (numToWrite - done), 
				   &transferred, NULL);
		    aio->bytesTransferred += transferred;
		}
		if (!ok) {
		    aio->pendingError = GetLastError();
		}  
	    }
	}
	SetEvent(aio->ov.hEvent);
	if (aio->pendingError != NO_ERROR || aio->bytesTransferred == 0)
	    break;
	if (aio->flags & DF_EXIT_THREAD)
	    break;
    }
    CloseHandle(aio->fd);
    aio->fd = INVALID_HANDLE_VALUE;
    return 0;
}

static HANDLE
translate_fd(int fd)
{
    DWORD access;
    HANDLE handle;

    switch (fd) {
    case 0:
	access = GENERIC_READ;
	handle = GetStdHandle(STD_INPUT_HANDLE);
	break;
    case 1:
	access = GENERIC_WRITE;
	handle = GetStdHandle(STD_OUTPUT_HANDLE);
	break;
    case 2:
	access = GENERIC_WRITE;
	handle = GetStdHandle(STD_ERROR_HANDLE);
	break;
    default:
	return (HANDLE) fd;
    }
    DEBUGF(("translate_fd(%d) -> std(%d)\n", fd, handle));

    if (handle == INVALID_HANDLE_VALUE || handle == 0) {
	handle = CreateFile("nul", access, 0,
			    NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    }
    DEBUGF(("translate_fd(%d) -> %d\n", fd, handle));
    return handle;
}

static ErlDrvData
fd_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
{
    DriverData* dp;
    int is_std_error = (opts->ofd == 2);
    
    opts->ifd = (int) translate_fd(opts->ifd);
    opts->ofd = (int) translate_fd(opts->ofd);
    if ((dp = new_driver_data(port_num, opts->packet_bytes, 2, TRUE)) == NULL)
	return ERL_DRV_ERROR_GENERAL;
    
    if (!create_file_thread(&dp->in, DO_READ)) {
	dp->port_num = PORT_FREE;
	return ERL_DRV_ERROR_GENERAL;
    }

    if (!create_file_thread(&dp->out, DO_WRITE)) {
	dp->port_num = PORT_FREE;
	return ERL_DRV_ERROR_GENERAL;
    }
    
    fd_driver_input = &(dp->in);
    dp->in.flags = DF_XLAT_CR;
    if (is_std_error) {
	dp->out.flags |= DF_DROP_IF_INVH; /* Just drop messages if stderror
					     is an invalid handle */
    }
    return set_driver_data(dp, opts->ifd, opts->ofd, opts->read_write, 0);
}

static void fd_stop(ErlDrvData d)
{
  int fd = (int)d;
  /*
   * I don't know a clean way to terminate the threads
   * (TerminateThread() doesn't release the stack),
   * so will we'll let the threads live.  Normally, the fd
   * driver is only used to support the -oldshell option,
   * so this shouldn't be a problem in practice.
   *
   * Since we will not attempt to terminate the threads,
   * better not close the input or output files either.
   */

  driver_data[fd].in.thread = (HANDLE) -1;
  driver_data[fd].out.thread = (HANDLE) -1;
  driver_data[fd].in.fd = INVALID_HANDLE_VALUE;
  driver_data[fd].out.fd = INVALID_HANDLE_VALUE;

  /*return */ common_stop(fd);
}

static ErlDrvData
vanilla_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
{
    HANDLE ofd,ifd;
    DriverData* dp;
    DWORD access;		/* Access mode: GENERIC_READ, GENERIC_WRITE. */
    DWORD crFlags;
    HANDLE this_process = GetCurrentProcess();

    access = 0;
    if (opts->read_write == DO_READ)
	access |= GENERIC_READ;
    if (opts->read_write == DO_WRITE)
	access |= GENERIC_WRITE;

    if (opts->read_write == DO_READ)
	crFlags = OPEN_EXISTING;
    else if (opts->read_write == DO_WRITE)
	crFlags = CREATE_ALWAYS;
    else
	crFlags = OPEN_ALWAYS;

    if ((dp = new_driver_data(port_num, opts->packet_bytes, 2, FALSE)) == NULL)
	return ERL_DRV_ERROR_GENERAL;
    ofd = CreateFile(name, access, FILE_SHARE_READ | FILE_SHARE_WRITE,
		    NULL, crFlags, FILE_ATTRIBUTE_NORMAL, NULL);
    if (!DuplicateHandle(this_process, (HANDLE) ofd,	
			 this_process, &ifd, 0,
			 FALSE, DUPLICATE_SAME_ACCESS)) {
	CloseHandle(ofd);
	ofd = INVALID_HANDLE_VALUE;
    }
    if (ofd == INVALID_HANDLE_VALUE)
	return ERL_DRV_ERROR_GENERAL;
    return set_driver_data(dp, ifd, ofd, opts->read_write,0);
}

static void
stop(ErlDrvData index)
{
    common_stop((int)index);
}

static void common_stop(int index)
{
    DriverData* dp = driver_data+index;

    DEBUGF(("common_stop(%d)\n", index));

    if (dp->in.ov.hEvent != NULL) {
	(void) driver_select(dp->port_num,
			     (ErlDrvEvent)dp->in.ov.hEvent,
			     ERL_DRV_READ, 0);
    }
    if (dp->out.ov.hEvent != NULL) {
	(void) driver_select(dp->port_num,
			     (ErlDrvEvent)dp->out.ov.hEvent,
			     ERL_DRV_WRITE, 0);
    }    

    if (dp->out.thread == (HANDLE) -1 && dp->in.thread == (HANDLE) -1) {
	release_driver_data(dp);
    } else {
	/*
	 * If there are read or write threads, start a thread which will
	 * wait for them to finish.
	 */
	HANDLE thread;
	DWORD tid;
	dp->port_num = PORT_EXITING;
	thread = (HANDLE *) _beginthreadex(NULL, 0, threaded_exiter, dp, 0, &tid);
	CloseHandle(thread);
    }
}

DWORD WINAPI
threaded_exiter(LPVOID param)
{
    DriverData* dp = (DriverData *) param;
    HANDLE handles[2];
    int i;

    /*
     * Ask the threads to terminated.
     *
     * Note that we can't reliable test the state of the ioAllowed event,
     * because it is an auto reset event.  Therefore, always set the
     * exit flag and signal the event.
     */

    i = 0;
    if (dp->out.thread != (HANDLE) -1) {
	dp->out.flags = DF_EXIT_THREAD;
	SetEvent(dp->out.ioAllowed);
	handles[i++] = dp->out.thread;
    }
    if (dp->in.thread != (HANDLE) -1) {
	dp->in.flags = DF_EXIT_THREAD;
	SetEvent(dp->in.ioAllowed);
	handles[i++] = dp->in.thread;
    }

    /*
     * If we were lucky, the following happened above:
     * 	1) The output thread terminated (and closed the pipe).
     *  2) As a consequence of that, the port program received
     *     EOF on its standard input.
     *  3) Hopefully, because of (2), the port program terminated.
     *  4) Because of (3), the input thread terminated.
     *
     * But this might need some time; therefore, we must wait for
     * both threads to terminate.
     */

    if (i > 0) {
	switch (WaitForMultipleObjects(i, handles, TRUE, 5000)) {
	case WAIT_TIMEOUT:
	    DEBUGF(("Timeout waiting for %d threads failed\n", i));
	    break;
	case WAIT_FAILED:
	    DEBUGF(("Wait for %d threads failed: %s\n",
		    i, win32_errorstr(GetLastError())));
	    break;
	default:
	    break;
	}
    }

    /*
     * Wait for threads to terminate didn't help.  Now use some force.
     * TerminateThread() is *not* a good idea, because it doesn't clean
     * up the thread's stack.
     *
     * Instead we well terminate the port program and wait for the
     * threads to terminate themselves when they receive end of file.
     */

    if (dp->out.thread != (HANDLE) -1) {
	int error;

	if (WaitForSingleObject(dp->out.thread, 0) == WAIT_OBJECT_0) {
	    CloseHandle(dp->out.thread);
	    dp->out.thread = (HANDLE) -1;
	} else if (dp->port_pid != INVALID_HANDLE_VALUE) {
	    DEBUGF(("Killing port process 0x%x (output thread)\n", dp->port_pid));
	    TerminateProcess(dp->port_pid, 0);
	    if (!CloseHandle(dp->port_pid))
	        DEBUGF(("Failed to close output handle!!!\n"));
	    dp->port_pid = INVALID_HANDLE_VALUE;
	    DEBUGF(("Waiting for output thread 0x%x to finish\n", dp->out.thread));
	    error = WaitForSingleObject(dp->out.thread, INFINITE);
	}
    }
    
    if (dp->in.thread != (HANDLE) -1) {
	if (WaitForSingleObject(dp->in.thread, 0) == WAIT_OBJECT_0) {
	    CloseHandle(dp->in.thread);
	    dp->in.thread = (HANDLE) -1;
	} else if (dp->port_pid != INVALID_HANDLE_VALUE) {
	    DEBUGF(("Killing port process 0x%x (input thread)\n", dp->port_pid));
	    TerminateProcess(dp->port_pid, 0);
	    if (!CloseHandle(dp->port_pid))
	        DEBUGF(("Failed to close input handle!!!\n"));
	    dp->port_pid = INVALID_HANDLE_VALUE;

	    DEBUGF(("Waiting for input thread 0x%x to finish\n", dp->in.thread));
	    switch (WaitForSingleObject(dp->in.thread, INFINITE)) {
	    case WAIT_OBJECT_0:
		CloseHandle(dp->in.thread);
		dp->in.thread = (HANDLE) -1;
		break;
	    default:
		DEBUGF(("Wait for input thread to finish failed: %s\n",
			win32_errorstr(GetLastError())));
		break;
	    }
	}
    }

    release_driver_data(dp);
    return 0;
}

/* ----------------------------------------------------------------------
 * output --
 * 	Outputs data from Erlang to the port program.
 *
 * Results:
 *	Returns the actual number of bytes written (including the
 *	packet header) or -1 if an error occurred.
 * ----------------------------------------------------------------------
 */

static void
output(ErlDrvData drv_data, char* buf, int len)
/*     long drv_data;		/* The slot to use in the driver data table.
				 * For Windows NT, this is *NOT* a file handle.
				 * The handle is found in the driver data.
				 */
/*     char *buf;			/* Pointer to data to write to the port program. */
/*     int len;			/* Number of bytes to write. */
{
    DriverData* dp;
    int pb;			/* The header size for this port. */
    int port_num;		/* The actual port number (for diagnostics). */
    char* current;

    dp = driver_data + (int)drv_data;
    if ((port_num = dp->port_num) == -1)
	return ; /*-1;*/

    pb = dp->packet_bytes;

    if ((pb+len) == 0)
	return ; /* 0; */

    /*
     * Check that the message can be sent with given header length.
     */

    if ((pb == 2 && len > 65535) || (pb == 1 && len > 255)) {
	driver_failure_posix(port_num, EINVAL);
	return ; /* -1; */
    }

    /*
     * Allocate memory for both the message and the header.
     */

    ASSERT(dp->outbuf == NULL);
    ASSERT(dp->outBufSize == 0);

    ASSERT(!dp->outbuf);
    dp->outbuf = DRV_BUF_ALLOC(pb+len);
    if (!dp->outbuf) {
	driver_failure_posix(port_num, ENOMEM);
	return ; /* -1; */
    }

    dp->outBufSize = pb+len;
    erts_smp_atomic_add(&sys_misc_mem_sz, dp->outBufSize);

    /*
     * Store header bytes (if any).
     */

    current = dp->outbuf;
    switch (pb) {
    case 4:
	*current++ = (len >> 24) & 255;
	*current++ = (len >> 16) & 255;
    case 2:
	*current++ = (len >> 8) & 255;
    case 1:
	*current++ = len & 255;
    }

    /*
     * Start the write.
     */

    if (len)
	memcpy(current, buf, len);
    
    if (!async_write_file(&dp->out, dp->outbuf, pb+len)) {
	set_busy_port(port_num, 1);
    } else {
	dp->out.ov.Offset += pb+len; /* For vanilla driver. */
	/* XXX OffsetHigh should be changed too. */
	ASSERT(erts_smp_atomic_read(&sys_misc_mem_sz) >= dp->outBufSize);
	erts_smp_atomic_add(&sys_misc_mem_sz, -1*dp->outBufSize);
	DRV_BUF_FREE(dp->outbuf);
	dp->outBufSize = 0;
	dp->outbuf = NULL;
    }
    /*return 0;*/
}


/* ----------------------------------------------------------------------
 * ready_input --
 *	This function is called (indirectly) from check_io() when an
 *	event object has been signaled, indicating that there is
 *	something to read on the corresponding file handle.
 *
 *	If the port is working in the continous stream mode (packet_bytes == 0),
 *	whatever data read will be sent straight to Erlang.
 *
 * Results:
 *	Always 0.
 * ----------------------------------------------------------------------
 */

static void
ready_input(ErlDrvData drv_data, ErlDrvEvent ready_event)
/*     long drv_data;		/* Driver data. */
/*     HANDLE ready_event;	/* The handle for the ready event. */
{
    int error = 0;		/* The error code (assume initially no errors). */
    DWORD bytesRead;		/* Number of bytes read. */
    DriverData* dp;
    int pb;

    dp = driver_data+(int)drv_data;
    pb = dp->packet_bytes;
#ifdef ERTS_SMP
    if(dp->in.thread == (HANDLE) -1) {
	dp->in.async_io_active = 0;
    }
#endif
    DEBUGF(("ready_input: dp %p, event 0x%x\n", dp, ready_event));

    /*
     * Evaluate the result of the overlapped read.
     */

#ifdef HARD_POLL_DEBUG
     poll_debug_read_begin(dp->in.ov.hEvent);
#endif

    error = get_overlapped_result(&dp->in, &bytesRead, TRUE);

#ifdef HARD_POLL_DEBUG
    poll_debug_read_done(dp->in.ov.hEvent,bytesRead);
#endif

    if (error == NO_ERROR) {
	if (pb == 0) { /* Continous stream. */
#ifdef DEBUG
	    DEBUGF(("ready_input: %d: ", bytesRead));
	    erl_bin_write(dp->inbuf, 16, bytesRead);
	    DEBUGF(("\n"));
#endif
	    driver_output(dp->port_num, dp->inbuf, bytesRead);
	} else {			/* Packet mode */
	    dp->bytesInBuffer += bytesRead;

	    /*
	     * Loop until we've exhausted the data in the buffer.
	     */

	    for (;;) {

		/*
		 * Check for completion of a header read.
		 */

		if (dp->bytesInBuffer >= dp->totalNeeded &&
		    dp->totalNeeded == pb) {

		    /*
		     * We have successfully read the packet header
		     * (and perhaps even the packet).  Get the packet size
		     * from the header and update dp->totalNeeded to include
		     * the packet size.
		     */

		    int packet_size = 0;
		    unsigned char *header = (unsigned char *) dp->inbuf;
		    
		    switch (pb) {
		    case 4:
			packet_size = (packet_size << 8) | *header++;
			packet_size = (packet_size << 8) | *header++;
		    case 2:
			packet_size = (packet_size << 8) | *header++;
		    case 1:
			packet_size = (packet_size << 8) | *header++;
		    }
		    
		    dp->totalNeeded += packet_size;
		    
		    /*
		     * Make sure that the receive buffer is big enough.
		     */
		    
		    if (dp->inBufSize < dp->totalNeeded) {
			char* new_buf;
		    
			new_buf = DRV_BUF_REALLOC(dp->inbuf, dp->totalNeeded);
			if (new_buf == NULL) {
			    error = ERROR_NOT_ENOUGH_MEMORY;
			    break; /* Break out of loop into error handler. */
			}
			ASSERT(erts_smp_atomic_read(&sys_misc_mem_sz) >= dp->inBufSize);
			erts_smp_atomic_add(&sys_misc_mem_sz,
					    dp->totalNeeded - dp->inBufSize);
			dp->inBufSize = dp->totalNeeded;
			dp->inbuf = new_buf;
		    }
		}
		
		/*
		 * Check for completion of a packet read.
		 */
		
		if (dp->bytesInBuffer < dp->totalNeeded) {
		    /*
		     * Not enough bytes in the buffer.  Break out of
		     * the loop and initiate a new read.
		     */

		    break;
		} else {
		    
		    /*
		     * We have successfully read a complete packet, which
		     * can be passed to Erlang.
		     */
		    
		    driver_output(dp->port_num, dp->inbuf+pb, dp->totalNeeded-pb);
		    
		    /*
		     * Update the number of bytes remaining in the buffer,
		     * and move the data remaining (if any) to the beginning
		     * of the buffer.
		     */
		    
		    dp->bytesInBuffer -= dp->totalNeeded;
		    if (dp->bytesInBuffer > 0) {
			memmove(dp->inbuf, dp->inbuf+dp->totalNeeded,
				dp->bytesInBuffer);
		    }
		    
		    /*
		     * Indicate that we need the size of a header, and
		     * go through the loop once more (to either process
		     * remaining bytes or initiate reading more).
		     */
		    
		    dp->totalNeeded = pb;
		}
	    }
	}
    }

    /*
     * Start a new overlapped read, or report the error.
     */

    if (error == NO_ERROR) {
	async_read_file(&dp->in, dp->inbuf+dp->bytesInBuffer,
			dp->inBufSize - dp->bytesInBuffer);
    } else {
	DEBUGF(("ready_input(): error: %s\n", win32_errorstr(error)));
	if (error == ERROR_BROKEN_PIPE || error == ERROR_HANDLE_EOF) {
	    /* Maybe check exit status */
	    if (dp->report_exit) {
		DWORD exitcode;
		if (GetExitCodeProcess(dp->port_pid, &exitcode) &&
		    exitcode != STILL_ACTIVE) {
		    driver_report_exit(dp->port_num, exitcode);
		}
	    }
	    driver_failure_eof(dp->port_num);
	} else {			/* Report real errors. */
	    int error = GetLastError();
	    (void) driver_select(dp->port_num, ready_event, ERL_DRV_READ, 0);
	    _dosmaperr(error);
	    driver_failure_posix(dp->port_num, errno);
	}
    }

    /*return 0;*/
}

static void
ready_output(ErlDrvData drv_data, ErlDrvEvent ready_event)
{
    DWORD bytesWritten;
    DriverData* dp = driver_data + (int)drv_data;
    int error;

#ifdef ERTS_SMP
    if(dp->out.thread == (HANDLE) -1) {
	dp->out.async_io_active = 0;
    }
#endif
    DEBUGF(("ready_output(%d, 0x%x)\n", drv_data, ready_event));
    set_busy_port(dp->port_num, 0);
    if (!(dp->outbuf)) {
	/* Happens because event sometimes get signalled during a succesful
	   write... */
	return;
    }
    ASSERT(erts_smp_atomic_read(&sys_misc_mem_sz) >= dp->outBufSize);
    erts_smp_atomic_add(&sys_misc_mem_sz, -1*dp->outBufSize);
    DRV_BUF_FREE(dp->outbuf);
    dp->outBufSize = 0;
    dp->outbuf = NULL;
#ifdef HARD_POLL_DEBUG
    poll_debug_write_begin(dp->out.ov.hEvent);
#endif
    error = get_overlapped_result(&dp->out, &bytesWritten, TRUE);
#ifdef HARD_POLL_DEBUG
    poll_debug_write_done(dp->out.ov.hEvent,bytesWritten);
#endif

    if (error == NO_ERROR) {
	dp->out.ov.Offset += bytesWritten; /* For vanilla driver. */
	return ; /* 0; */
    }

    (void) driver_select(dp->port_num, ready_event, ERL_DRV_WRITE, 0);
    _dosmaperr(error);
    driver_failure_posix(dp->port_num, errno);
    /* return 0; */
}

static void stop_select(ErlDrvEvent e, void* _)
{
    CloseHandle((HANDLE)e);
}

/* Fills in the systems representation of the beam process identifier.
** The Pid is put in STRING representation in the supplied buffer,
** no interpretation of this should be done by the rest of the
** emulator. The buffer should be at least 21 bytes long.
*/
void sys_get_pid(char *buffer){
    DWORD p = GetCurrentProcessId();
    /* The pid is scalar and is an unsigned long. */
    sprintf(buffer,"%lu",(unsigned long) p);
}

void
sys_init_io(void)
{
    
    /* Now heres an icky one... This is called before drivers are, so we
       can change our view of the number of open files possible.
       We estimate the number to twice the amount of ports. 
       We really dont know on windows, do we? */
    max_files = 2*erts_max_ports;
    
#ifdef USE_THREADS
#ifdef ERTS_SMP
    if (init_async(-1) < 0)
	erl_exit(1, "Failed to initialize async-threads\n");
#else
    {
	/* This is special stuff, starting a driver from the 
	 * system routines, but is a nice way of handling stuff
	 * the erlang way
	 */
	SysDriverOpts dopts;
	int ret;

	sys_memset((void*)&dopts, 0, sizeof(SysDriverOpts));
	add_driver_entry(&async_driver_entry);
	ret = erts_open_driver(NULL, NIL, "async", &dopts, NULL);
	DEBUGF(("open_driver = %d\n", ret));
	if (ret < 0)
	    erl_exit(1, "Failed to open async driver\n");
	erts_port[ret].status |= ERTS_PORT_SFLG_IMMORTAL;
    }
#endif
#endif
}

#ifdef ERTS_SMP
void
erts_sys_main_thread(void)
{
    HANDLE dummy;
#ifdef ERTS_ENABLE_LOCK_CHECK
    erts_lc_set_thread_name("parent_thread");
#endif
    dummy = CreateEvent(NULL, FALSE, FALSE, NULL);
    for(;;) {
	WaitForSingleObject(dummy, INFINITE);
    }
}
#endif

void erts_sys_alloc_init(void)
{
}

void *erts_sys_alloc(ErtsAlcType_t t, void *x, Uint sz)
{
    return malloc((size_t) sz);
}

void *erts_sys_realloc(ErtsAlcType_t t, void *x, void *p, Uint sz)
{
    return realloc(p, (size_t) sz);
}

void erts_sys_free(ErtsAlcType_t t, void *x, void *p)
{
    free(p);
}

static Preload* preloaded = NULL;
static unsigned* res_name = NULL;
static int num_preloaded = 0;

/* Return a pointer to a vector of names of preloaded modules */

Preload* sys_preloaded(void)
{
    HRSRC hRes;
    unsigned char* data;

#define GETWORD(p) (0[p] | 1[p] << 8)
#define GETDWORD(p) (GETWORD(p) | GETWORD(p+2) << 16)


    if (preloaded == NULL) {
	int i;
    ASSERT(beam_module != NULL);
    hRes = FindResource(beam_module, 0, "ERLANG_DICT");
    /* We might have a resource compiler laying out the 0 resource with
       "0" as a textual name instead... */
    if (hRes == NULL) {
	hRes = FindResource(beam_module, "0", "ERLANG_DICT");
    }
    if (hRes == NULL) {
	DWORD n = GetLastError();
	fprintf(stderr, "No ERLANG_DICT resource\n");
	exit(1);
    }
    data = (unsigned char *) LoadResource(beam_module, hRes);
    
    num_preloaded = GETWORD(data);
    if (num_preloaded == 0) {
	fprintf(stderr, "No preloaded modules\n");
	exit(1);
    }

    data += 2;
    preloaded = erts_alloc(ERTS_ALC_T_PRELOADED,
			   (num_preloaded+1)*sizeof(Preload));
    res_name = erts_alloc(ERTS_ALC_T_PRELOADED,
			  (num_preloaded+1)*sizeof(unsigned));
    erts_smp_atomic_add(&sys_misc_mem_sz,
			(num_preloaded+1)*sizeof(Preload)
			    + (num_preloaded+1)*sizeof(unsigned));
    for (i = 0; i < num_preloaded; i++) {
	int n;
	
	preloaded[i].size = GETDWORD(data);
	data += 4;
	res_name[i] = GETWORD(data);
	data += 2;
	n = GETWORD(data);
	data += 2;
	preloaded[i].name = erts_alloc(ERTS_ALC_T_PRELOADED, n+1);
	erts_smp_atomic_add(&sys_misc_mem_sz, n+1);
	sys_memcpy(preloaded[i].name, data, n);
	preloaded[i].name[n] = '\0';
	data += n;
	DEBUGF(("name: %s; size: %d; resource: %p\n",
		preloaded[i].name, preloaded[i].size, res_name[i]));
    }
    preloaded[i].name = NULL;
    }
    
#undef GETWORD
#undef GETDWORD
    return preloaded;
}

/* Return a pointer to preloaded code for module "module" */
unsigned char* sys_preload_begin(Preload* pp)
{
    HRSRC hRes;
    unsigned resource;
    
    ASSERT(beam_module != NULL);

    resource = res_name[pp-preloaded];
    DEBUGF(("Loading name: %s; size: %d; resource: %p\n",
	    pp->name, pp->size, resource));
    hRes = FindResource(beam_module, (char *) resource, "ERLANG_CODE");
    return pp->code = LoadResource(beam_module, hRes);
}

/* Clean up if allocated */
void sys_preload_end(Preload* pp)
{
}

/* Read a key from console */

int
sys_get_key(int fd)
{
    ASSERT(fd == 0);

    if (win_console) {
        return ConGetKey();
    }

    /*
     * Black magic follows. (Code stolen from get_overlapped_result())
     */

    if (fd_driver_input != NULL && fd_driver_input->thread != (HANDLE)-1) {
	DWORD error;
	int key;

	error = WaitForSingleObject(fd_driver_input->ov.hEvent, INFINITE);
	if (error == WAIT_OBJECT_0) {
	    if (fd_driver_input->bytesTransferred > 0) {
		int n;
		int i;
		char* buf = OV_BUFFER_PTR(fd_driver_input);

		fd_driver_input->bytesTransferred--;
		n = fd_driver_input->bytesTransferred;
		key = buf[0];
		for (i = n; i > 0; i--) {
		    buf[i-1] = buf[i];
		}
		return key;
	    }
	}
    }
    return '*';		/* Error! */
}

/*
 * Returns a human-readable description of the last error.
 * The returned pointer will be valid only as long as last-error()
 * isn't called again.
 */

char* win32_errorstr(int error)
{
#ifdef SMP
  LPTSTR lpBufPtr = erts_smp_tsd_get(win32_errstr_key);
#else
  static LPTSTR lpBufPtr = NULL;
#endif
  if (lpBufPtr) {
      LocalFree(lpBufPtr);
  }
  FormatMessage(
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
		FORMAT_MESSAGE_IGNORE_INSERTS,
		NULL,
		error,
		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
		(LPTSTR) &lpBufPtr,
		0,
		NULL);
  SetLastError(error);
#ifdef ERTS_SMP
  erts_smp_tsd_set(win32_errstr_key,lpBufPtr);
#endif
  return lpBufPtr;
}

char* last_error(void)
{
  return win32_errorstr(GetLastError());
}

static void* sys_func_memzero(void* s, size_t n)
{
    return sys_memzero(s, n);
}

#ifdef DEBUG
static HANDLE hDebugWrite = INVALID_HANDLE_VALUE;

void erl_debug(char *fmt,...)
{
  char sbuf[1024];		/* Temporary buffer. */
  DWORD written;		/* Actual number of chars written. */
  va_list va;

  if (hDebugWrite != INVALID_HANDLE_VALUE) {
    va_start(va, fmt);
    vsprintf(sbuf, fmt, va);
    WriteFile(hDebugWrite, sbuf, strlen(sbuf), &written, NULL);
    va_end(va);
  }
}

static void debug_console(void)
{
  HANDLE hRead;			/* Handle to read end of pipe. */
  SECURITY_ATTRIBUTES sa;
  PROCESS_INFORMATION procInfo;
  STARTUPINFO startInfo;
  BOOL ok;

  /*
   * Create a pipe for communicating with the sub process.
   */

  sa.nLength = sizeof(sa);
  sa.lpSecurityDescriptor = NULL;
  sa.bInheritHandle = TRUE;
  if (!CreatePipe(&hRead, &hDebugWrite, &sa, 0)) {
    fprintf(stderr, "Failed to create pipe: %d\n", 
	    GetLastError());
    exit(1);
  }

  startInfo.cb = sizeof(STARTUPINFO);
  startInfo.lpTitle = "Erlang Debug Log";
  startInfo.lpReserved = NULL; 
  startInfo.lpReserved2 = NULL; 
  startInfo.cbReserved2 = 0; 
  startInfo.lpDesktop = NULL;  
  startInfo.dwFlags = STARTF_USESTDHANDLES;
  startInfo.hStdInput = hRead;

  /* The following handles are not intended to be used. */
  startInfo.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
  startInfo.hStdError = GetStdHandle(STD_ERROR_HANDLE);

  ok = CreateProcess(NULL,
		     "erl_log.exe", /* Application */
		     NULL,	/* Process security attributes. */
		     NULL,	/* Thread security attributes. */
		     TRUE,	/* Handle inheritance flag. */
		     CREATE_NEW_CONSOLE, /* Flags. */
		     NULL,	/* Environment. */
		     NULL,	/* Current directory. */
		     &startInfo,/* Startup info. */
		     &procInfo	/* Process information. */
		     );

  CloseHandle(hRead); 

  if (ok) {
    /*
     * Since we don't use these, close them at once to avoid a resource
     * leak.
     */
    CloseHandle(procInfo.hProcess);
    CloseHandle(procInfo.hThread);
  } else {
    fprintf(stderr, "Create process failed: %s\n", last_error());
    exit(1);
  }
}

void
erl_bin_write(buf, sz, max)
     unsigned char* buf;
     int sz;
     int max;
{
  int i, imax;
  char comma[5] = ",";

  if (hDebugWrite == INVALID_HANDLE_VALUE)
    return;

  if (!sz)
    return;
  if (sz > max)
    imax = max;
  else
    imax = sz;
  
  for (i=0; i<imax; i++) {
    if (i == imax-1) {
      if (sz > max)
	strcpy(comma, ",...");
      else
	comma[0] = 0;
    }
    if (isdigit(buf[i]))
      erl_debug("%u%s", (int)(buf[i]), comma);
    else {
      if (isalpha(buf[i])) {
	erl_debug("%c%s", buf[i], comma);
      }
      else
	erl_debug("%u%s", (int)(buf[i]), comma);
    }
  }
}

void
erl_assert_error(char* expr, char* file, int line)
{   
    char message[1024];

    sprintf(message, "File %hs, line %d: %hs", file, line, expr);
    MessageBox(GetActiveWindow(), message, "Assertion failed",
	       MB_OK | MB_ICONERROR);
#if 0
    erl_crash_dump(file, line, "Assertion failed: %hs\n", expr);
#endif
    DebugBreak();
}

#endif /* DEBUG */
	    
static void
check_supported_os_version(void)
{
#if defined(_WIN32_WINNT)
    {
	DWORD major = (_WIN32_WINNT >> 8) & 0xff;
	DWORD minor = _WIN32_WINNT & 0xff;

	if (int_os_version.dwPlatformId != VER_PLATFORM_WIN32_NT
	    || int_os_version.dwMajorVersion < major
	    || (int_os_version.dwMajorVersion == major
		&& int_os_version.dwMinorVersion < minor))
	    erl_exit(-1,
		     "Windows version not supported "
		     "(min required: winnt %d.%d)\n",
		     major, minor);
    }
#else
    erl_exit(-1,
	     "Windows version not supported "
	     "(min required: win %d.%d)\n",
	     nt_major, nt_minor);
#endif
}

#ifdef USE_THREADS
#ifdef ERTS_ENABLE_LOCK_COUNT
static void
thr_create_prepare_child(void *vtcdp)
{
    erts_lcnt_thread_setup();
}
#endif /* ERTS_ENABLE_LOCK_COUNT */
#endif /* USE_THREADS */

void
erts_sys_pre_init(void)
{
    int_os_version.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
    GetVersionEx(&int_os_version);
    check_supported_os_version();
#ifdef USE_THREADS
    {
	erts_thr_init_data_t eid = ERTS_THR_INIT_DATA_DEF_INITER;
#ifdef ERTS_ENABLE_LOCK_COUNT
	eid.thread_create_child_func = thr_create_prepare_child;
#endif
	erts_thr_init(&eid);
#ifdef ERTS_ENABLE_LOCK_COUNT
	erts_lcnt_init();
#endif
    }
#endif
    erts_smp_atomic_init(&sys_misc_mem_sz, 0);
}

void noinherit_std_handle(DWORD type)
{
    HANDLE h = GetStdHandle(type);
    if (h != 0 && h != INVALID_HANDLE_VALUE) {
	SetHandleInformation(h,HANDLE_FLAG_INHERIT,0);
    }
}
	    

void erl_sys_init(void)
{
    HANDLE handle;

    erts_sys_env_init();

    noinherit_std_handle(STD_OUTPUT_HANDLE);
    noinherit_std_handle(STD_INPUT_HANDLE);
    noinherit_std_handle(STD_ERROR_HANDLE);


    erts_smp_mtx_init(&sys_driver_data_lock, "sys_driver_data_lock");

#ifdef ERTS_SMP
    erts_smp_tsd_key_create(&win32_errstr_key);
#endif
    erts_smp_atomic_init(&pipe_creation_counter,0);
    /*
     * Test if we have named pipes or not.
     */

    switch (int_os_version.dwPlatformId) {
    case VER_PLATFORM_WIN32_WINDOWS:
	DEBUGF(("Running on Windows 95"));
	use_named_pipes = FALSE;
	break;
    case VER_PLATFORM_WIN32_NT:
	DEBUGF(("Running on Windows NT"));
#ifdef DISABLE_NAMED_PIPES
	use_named_pipes = FALSE;
#else
	use_named_pipes = TRUE;
#endif
	break;
    default:			/* Unsupported platform. */
	exit(1);
    }
    DEBUGF((" %d.%d, build %d, %s\n",
	    int_os_version.dwMajorVersion, int_os_version.dwMinorVersion,
	    int_os_version.dwBuildNumber, int_os_version.szCSDVersion));

    ASSERT(beam_module != NULL);
    init_console();

    /*
     * The following makes sure that the current directory for the current drive
     * is remembered (in the environment).
     */  

    chdir(".");

    /*
     * Make sure that the standard error handle is valid.
     */
    handle = GetStdHandle(STD_ERROR_HANDLE);
    if (handle == INVALID_HANDLE_VALUE || handle == 0) {
	SetStdHandle(STD_ERROR_HANDLE, GetStdHandle(STD_OUTPUT_HANDLE));
    }
    erts_sys_init_float();
    erts_init_check_io();

    /* Suppress windows error message popups */
    SetErrorMode(SetErrorMode(0) |
		 SEM_FAILCRITICALERRORS | SEM_NOOPENFILEERRORBOX); 
}

#ifdef ERTS_SMP
void
erts_sys_schedule_interrupt(int set)
{
    erts_check_io_interrupt(set);
}

void
erts_sys_schedule_interrupt_timed(int set, long msec)
{
    erts_check_io_interrupt_timed(set, msec);
}
#endif

/*
 * Called from schedule() when it runs out of runnable processes,
 * or when Erlang code has performed INPUT_REDUCTIONS reduction
 * steps. runnable == 0 iff there are no runnable Erlang processes.
 */
void
erl_sys_schedule(int runnable)
{
#ifdef ERTS_SMP
    erts_check_io(!runnable);
    ERTS_SMP_LC_ASSERT(!ERTS_LC_IS_BLOCKING);
#else
    erts_check_io_interrupt(0);
    if (runnable) {
	erts_check_io(0);	/* Poll for I/O */
	check_async_ready();	/* Check async completions */
    } else {
	erts_check_io(check_async_ready() ? 0 : 1);
    }
#endif
}

#if defined(USE_THREADS) && !defined(ERTS_SMP)
/*
 * Async operation support.
 */

static ErlDrvEvent async_drv_event;

void
sys_async_ready(int fd)
{
    SetEvent((HANDLE)async_drv_event);
}

static int
async_drv_init(void)
{
    async_drv_event = (ErlDrvEvent) NULL;
    return 0;
}

static ErlDrvData
async_drv_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
{
    if (async_drv_event != (ErlDrvEvent) NULL) {
	return ERL_DRV_ERROR_GENERAL;
    }
    if ((async_drv_event = (ErlDrvEvent)CreateAutoEvent(FALSE)) == (ErlDrvEvent) NULL) {
	return ERL_DRV_ERROR_GENERAL;
    }

    driver_select(port_num, async_drv_event, ERL_DRV_READ|ERL_DRV_USE, 1);
    if (init_async(async_drv_event) < 0) {
	return ERL_DRV_ERROR_GENERAL;
    }
    return (ErlDrvData)port_num;
}

static void
async_drv_stop(ErlDrvData port_num)
{
    exit_async();
    driver_select((ErlDrvPort)port_num, async_drv_event, ERL_DRV_READ|ERL_DRV_USE, 0);
    /*CloseHandle((HANDLE)async_drv_event);*/
    async_drv_event = (ErlDrvEvent) NULL;
}


static void
async_drv_input(ErlDrvData port_num, ErlDrvEvent e) 
{
    check_async_ready();

    /*
     * Our event is auto-resetting.
     */
}

#endif