dlls/krnl386.exe16/task.c

   1 /*
   2  * Task functions
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <stdarg.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <assert.h>
  28 #ifdef HAVE_UNISTD_H
  29 # include <unistd.h>
  30 #endif
  31
  32 #include "windef.h"
  33 #include "winbase.h"
  34 #include "wingdi.h"
  35 #include "winnt.h"
  36 #include "wownt32.h"
  37 #include "winuser.h"
  38
  39 #include "wine/winbase16.h"
  40 #include "winternl.h"
  41 #include "kernel16_private.h"
  42
  43 #include "wine/debug.h"
  44
  45 WINE_DEFAULT_DEBUG_CHANNEL(task);
  46
  47 #include "pshpack1.h"
  48
  49 struct thunk
  50 {
  51     BYTE      movw;
  52     HANDLE16  instance;
  53     BYTE      ljmp;
  54     FARPROC16 func;
  55 };
  56
  57 /* Segment containing MakeProcInstance() thunks */
  58 typedef struct
  59 {
  60     WORD  next;       /* Selector of next segment */
  61     WORD  magic;      /* Thunks signature */
  62     WORD  unused;
  63     WORD  free;       /* Head of the free list */
  64     struct thunk thunks[1];
  65 } THUNKS;
  66
  67 #include "poppack.h"
  68
  69 #define THUNK_MAGIC  ('P' | ('T' << 8))
  70
  71   /* Min. number of thunks allocated when creating a new segment */
  72 #define MIN_THUNKS  32
  73
  74 #define TDB_MAGIC    ('T' | ('D' << 8))
  75
  76 static THHOOK DefaultThhook;
  77 THHOOK *pThhook = &DefaultThhook;
  78
  79 #define hFirstTask   (pThhook->HeadTDB)
  80 #define hLockedTask  (pThhook->LockTDB)
  81
  82 static UINT16 nTaskCount = 0;
  83
  84 static HTASK16 initial_task, main_task;
  85
  86 /***********************************************************************
  87  *           TASK_InstallTHHook
  88  */
  89 void TASK_InstallTHHook( THHOOK *pNewThhook )
  90 {
  91      THHOOK *pOldThhook = pThhook;
  92
  93      pThhook = pNewThhook? pNewThhook : &DefaultThhook;
  94
  95      *pThhook = *pOldThhook;
  96 }
  97
  98 /***********************************************************************
  99  *           TASK_GetPtr
 100  */
 101 static TDB *TASK_GetPtr( HTASK16 hTask )
 102 {
 103     return GlobalLock16( hTask );
 104 }
 105
 106
 107 /***********************************************************************
 108  *           TASK_GetCurrent
 109  */
 110 TDB *TASK_GetCurrent(void)
 111 {
 112     return TASK_GetPtr( GetCurrentTask() );
 113 }
 114
 115
 116 /***********************************************************************
 117  *           TASK_LinkTask
 118  */
 119 static void TASK_LinkTask( HTASK16 hTask )
 120 {
 121     HTASK16 *prevTask;
 122     TDB *pTask;
 123
 124     if (!(pTask = TASK_GetPtr( hTask ))) return;
 125     prevTask = &hFirstTask;
 126     while (*prevTask)
 127     {
 128         TDB *prevTaskPtr = TASK_GetPtr( *prevTask );
 129         if (prevTaskPtr->priority >= pTask->priority) break;
 130         prevTask = &prevTaskPtr->hNext;
 131     }
 132     pTask->hNext = *prevTask;
 133     *prevTask = hTask;
 134     nTaskCount++;
 135 }
 136
 137
 138 /***********************************************************************
 139  *           TASK_UnlinkTask
 140  */
 141 static void TASK_UnlinkTask( HTASK16 hTask )
 142 {
 143     HTASK16 *prevTask;
 144     TDB *pTask;
 145
 146     prevTask = &hFirstTask;
 147     while (*prevTask && (*prevTask != hTask))
 148     {
 149         pTask = TASK_GetPtr( *prevTask );
 150         prevTask = &pTask->hNext;
 151     }
 152     if (*prevTask)
 153     {
 154         pTask = TASK_GetPtr( *prevTask );
 155         *prevTask = pTask->hNext;
 156         pTask->hNext = 0;
 157         nTaskCount--;
 158     }
 159 }
 160
 161
 162 /***********************************************************************
 163  *           TASK_CreateThunks
 164  *
 165  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 166  * and containing 'count' entries.
 167  */
 168 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 169 {
 170     int i;
 171     THUNKS *pThunk;
 172
 173     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 174     pThunk->next = 0;
 175     pThunk->magic = THUNK_MAGIC;
 176     pThunk->free = FIELD_OFFSET( THUNKS, thunks );
 177     for (i = 0; i < count-1; i++)
 178         *(WORD *)&pThunk->thunks[i] = FIELD_OFFSET( THUNKS, thunks[i+1] );
 179     *(WORD *)&pThunk->thunks[i] = 0;  /* Last thunk */
 180 }
 181
 182
 183 /***********************************************************************
 184  *           TASK_AllocThunk
 185  *
 186  * Allocate a thunk for MakeProcInstance().
 187  */
 188 static SEGPTR TASK_AllocThunk(void)
 189 {
 190     TDB *pTask;
 191     THUNKS *pThunk;
 192     WORD sel, base;
 193
 194     if (!(pTask = TASK_GetCurrent())) return 0;
 195     sel = pTask->hCSAlias;
 196     pThunk = (THUNKS *)pTask->thunks;
 197     base = (char *)pThunk - (char *)pTask;
 198     while (!pThunk->free)
 199     {
 200         sel = pThunk->next;
 201         if (!sel)  /* Allocate a new segment */
 202         {
 203             sel = GLOBAL_Alloc( GMEM_FIXED, FIELD_OFFSET( THUNKS, thunks[MIN_THUNKS] ),
 204                                 pTask->hPDB, WINE_LDT_FLAGS_CODE );
 205             if (!sel) return 0;
 206             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 207             pThunk->next = sel;
 208         }
 209         pThunk = GlobalLock16( sel );
 210         base = 0;
 211     }
 212     base += pThunk->free;
 213     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 214     return MAKESEGPTR( sel, base );
 215 }
 216
 217
 218 /***********************************************************************
 219  *           TASK_FreeThunk
 220  *
 221  * Free a MakeProcInstance() thunk.
 222  */
 223 static BOOL TASK_FreeThunk( SEGPTR thunk )
 224 {
 225     TDB *pTask;
 226     THUNKS *pThunk;
 227     WORD sel, base;
 228
 229     if (!(pTask = TASK_GetCurrent())) return FALSE;
 230     sel = pTask->hCSAlias;
 231     pThunk = (THUNKS *)pTask->thunks;
 232     base = (char *)pThunk - (char *)pTask;
 233     while (sel && (sel != HIWORD(thunk)))
 234     {
 235         sel = pThunk->next;
 236         pThunk = GlobalLock16( sel );
 237         base = 0;
 238     }
 239     if (!sel) return FALSE;
 240     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 241     pThunk->free = LOWORD(thunk) - base;
 242     return TRUE;
 243 }
 244
 245
 246 /***********************************************************************
 247  *           TASK_Create
 248  *
 249  * NOTE: This routine might be called by a Win32 thread. Thus, we need
 250  *       to be careful to protect global data structures. We do this
 251  *       by entering the Win16Lock while linking the task into the
 252  *       global task list.
 253  */
 254 static TDB *TASK_Create( NE_MODULE *pModule, UINT16 cmdShow, LPCSTR cmdline, BYTE len )
 255 {
 256     HTASK16 hTask;
 257     TDB *pTask;
 258     FARPROC16 proc;
 259     char curdir[MAX_PATH];
 260     HMODULE16 hModule = pModule ? pModule->self : 0;
 261
 262       /* Allocate the task structure */
 263
 264     hTask = GlobalAlloc16( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB) );
 265     if (!hTask) return NULL;
 266     pTask = TASK_GetPtr( hTask );
 267     FarSetOwner16( hTask, hModule );
 268
 269     /* Fill the task structure */
 270
 271     pTask->hSelf = hTask;
 272
 273     pTask->version       = pModule ? pModule->ne_expver : 0x0400;
 274     pTask->hModule       = hModule;
 275     pTask->hParent       = GetCurrentTask();
 276     pTask->magic         = TDB_MAGIC;
 277     pTask->nCmdShow      = cmdShow;
 278
 279     GetCurrentDirectoryA( sizeof(curdir), curdir );
 280     GetShortPathNameA( curdir, curdir, sizeof(curdir) );
 281     pTask->curdrive = (curdir[0] - 'A') | 0x80;
 282     lstrcpynA( pTask->curdir, curdir + 2, sizeof(pTask->curdir) );
 283
 284       /* Create the thunks block */
 285
 286     TASK_CreateThunks( hTask, (char *)pTask->thunks - (char *)pTask, 7 );
 287
 288       /* Copy the module name */
 289
 290     if (hModule)
 291     {
 292         char name[sizeof(pTask->module_name)+1];
 293         size_t len;
 294         GetModuleName16( hModule, name, sizeof(name) );
 295         len = strlen(name) + 1;
 296         memcpy(pTask->module_name, name, min(len,sizeof(pTask->module_name)));
 297         pTask->compat_flags = GetProfileIntA( "Compatibility", name, 0 );
 298     }
 299
 300       /* Allocate a selector for the PDB */
 301
 302     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB16),
 303                                       hModule, WINE_LDT_FLAGS_DATA );
 304
 305       /* Fill the PDB */
 306
 307     pTask->pdb.int20 = 0x20cd;
 308     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 309     proc = GetProcAddress16( GetModuleHandle16("KERNEL"), "DOS3Call" );
 310     memcpy( &pTask->pdb.dispatcher[1], &proc, sizeof(proc) );
 311     pTask->pdb.savedint22 = 0;
 312     pTask->pdb.savedint23 = 0;
 313     pTask->pdb.savedint24 = 0;
 314     pTask->pdb.fileHandlesPtr =
 315         MAKESEGPTR( GlobalHandleToSel16(pTask->hPDB), FIELD_OFFSET( PDB16, fileHandles ));
 316     pTask->pdb.hFileHandles = 0;
 317     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 318     /* FIXME: should we make a copy of the environment? */
 319     pTask->pdb.environment    = SELECTOROF(GetDOSEnvironment16());
 320     pTask->pdb.nbFiles        = 20;
 321
 322     /* Fill the command line */
 323
 324     if (!cmdline)
 325     {
 326         cmdline = GetCommandLineA();
 327         /* remove the first word (program name) */
 328         if (*cmdline == '"')
 329             if (!(cmdline = strchr( cmdline+1, '"' ))) cmdline = GetCommandLineA();
 330         while (*cmdline && (*cmdline != ' ') && (*cmdline != '\t')) cmdline++;
 331         while ((*cmdline == ' ') || (*cmdline == '\t')) cmdline++;
 332         len = strlen(cmdline);
 333     }
 334     if (len >= sizeof(pTask->pdb.cmdLine)) len = sizeof(pTask->pdb.cmdLine)-1;
 335     pTask->pdb.cmdLine[0] = len;
 336     memcpy( pTask->pdb.cmdLine + 1, cmdline, len );
 337     /* pTask->pdb.cmdLine[len+1] = 0; */
 338
 339     TRACE("cmdline='%.*s' task=%04x\n", len, cmdline, hTask );
 340
 341       /* Allocate a code segment alias for the TDB */
 342
 343     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, pTask, sizeof(TDB),
 344                                           pTask->hPDB, WINE_LDT_FLAGS_CODE );
 345
 346       /* Default DTA overwrites command line */
 347
 348     pTask->dta = MAKESEGPTR( pTask->hPDB, FIELD_OFFSET( PDB16, cmdLine ));
 349
 350     /* Create scheduler event for 16-bit tasks */
 351
 352     if ( !(pTask->flags & TDBF_WIN32) )
 353         NtCreateEvent( &pTask->hEvent, EVENT_ALL_ACCESS, NULL, NotificationEvent, FALSE );
 354
 355     if (!initial_task) initial_task = hTask;
 356
 357     return pTask;
 358 }
 359
 360
 361 /***********************************************************************
 362  *           TASK_DeleteTask
 363  */
 364 static void TASK_DeleteTask( HTASK16 hTask )
 365 {
 366     TDB *pTask;
 367     HGLOBAL16 hPDB;
 368
 369     if (!(pTask = TASK_GetPtr( hTask ))) return;
 370     hPDB = pTask->hPDB;
 371
 372     pTask->magic = 0xdead; /* invalidate signature */
 373
 374     /* Free the selector aliases */
 375
 376     GLOBAL_FreeBlock( pTask->hCSAlias );
 377     GLOBAL_FreeBlock( pTask->hPDB );
 378
 379     /* Free the task module */
 380
 381     FreeModule16( pTask->hModule );
 382
 383     /* Free the task structure itself */
 384
 385     GlobalFree16( hTask );
 386
 387     /* Free all memory used by this task (including the 32-bit stack, */
 388     /* the environment block and the thunk segments). */
 389
 390     GlobalFreeAll16( hPDB );
 391 }
 392
 393
 394 /***********************************************************************
 395  *           TASK_CreateMainTask
 396  *
 397  * Create a task for the main (32-bit) process.
 398  */
 399 void TASK_CreateMainTask(void)
 400 {
 401     TDB *pTask;
 402     STARTUPINFOA startup_info;
 403     UINT cmdShow = 1; /* SW_SHOWNORMAL but we don't want to include winuser.h here */
 404
 405     GetStartupInfoA( &startup_info );
 406     if (startup_info.dwFlags & STARTF_USESHOWWINDOW) cmdShow = startup_info.wShowWindow;
 407     pTask = TASK_Create( NULL, cmdShow, NULL, 0 );
 408     if (!pTask)
 409     {
 410         ERR("could not create task for main process\n");
 411         ExitProcess(1);
 412     }
 413
 414     pTask->flags        |= TDBF_WIN32;
 415     pTask->hInstance     = 0;
 416     pTask->hPrevInstance = 0;
 417     pTask->teb           = NtCurrentTeb();
 418
 419     /* Add the task to the linked list */
 420     /* (no need to get the win16 lock, we are the only thread at this point) */
 421     TASK_LinkTask( pTask->hSelf );
 422     main_task = pTask->hSelf;
 423 }
 424
 425
 426 struct create_data
 427 {
 428     TDB                 *task;
 429     WIN16_SUBSYSTEM_TIB *tib;
 430 };
 431
 432 /* allocate the win16 TIB for a new 16-bit task */
 433 static WIN16_SUBSYSTEM_TIB *allocate_win16_tib( TDB *pTask )
 434 {
 435     WCHAR path[MAX_PATH];
 436     WIN16_SUBSYSTEM_TIB *tib;
 437     UNICODE_STRING *curdir;
 438     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 439
 440     if (!(tib = HeapAlloc( GetProcessHeap(), 0, sizeof(*tib) ))) return NULL;
 441     MultiByteToWideChar( CP_ACP, 0, NE_MODULE_NAME(pModule), -1, path, MAX_PATH );
 442     GetLongPathNameW( path, path, MAX_PATH );
 443     if (RtlCreateUnicodeString( &tib->exe_str, path )) tib->exe_name = &tib->exe_str;
 444     else tib->exe_name = NULL;
 445
 446     RtlAcquirePebLock();
 447     if (NtCurrentTeb()->Tib.SubSystemTib)
 448         curdir = &((WIN16_SUBSYSTEM_TIB *)NtCurrentTeb()->Tib.SubSystemTib)->curdir.DosPath;
 449     else
 450         curdir = &NtCurrentTeb()->Peb->ProcessParameters->CurrentDirectory.DosPath;
 451     tib->curdir.DosPath.MaximumLength = sizeof(tib->curdir_buffer);
 452     tib->curdir.DosPath.Length = min( curdir->Length, tib->curdir.DosPath.MaximumLength-sizeof(WCHAR) );
 453     tib->curdir.DosPath.Buffer = tib->curdir_buffer;
 454     tib->curdir.Handle = 0;
 455     memcpy( tib->curdir_buffer, curdir->Buffer, tib->curdir.DosPath.Length );
 456     tib->curdir_buffer[tib->curdir.DosPath.Length/sizeof(WCHAR)] = 0;
 457     RtlReleasePebLock();
 458     return tib;
 459 }
 460
 461 static inline void free_win16_tib( WIN16_SUBSYSTEM_TIB *tib )
 462 {
 463     if (tib->exe_name) RtlFreeUnicodeString( tib->exe_name );
 464     HeapFree( GetProcessHeap(), 0, tib );
 465 }
 466
 467 /* startup routine for a new 16-bit thread */
 468 static DWORD CALLBACK task_start( LPVOID p )
 469 {
 470     struct create_data *data = p;
 471     TDB *pTask = data->task;
 472     DWORD ret;
 473
 474     kernel_get_thread_data()->htask16 = pTask->hSelf;
 475     NtCurrentTeb()->Tib.SubSystemTib = data->tib;
 476     HeapFree( GetProcessHeap(), 0, data );
 477
 478     _EnterWin16Lock();
 479     TASK_LinkTask( pTask->hSelf );
 480     pTask->teb = NtCurrentTeb();
 481     ret = NE_StartTask();
 482     _LeaveWin16Lock();
 483     return ret;
 484 }
 485
 486
 487 /***********************************************************************
 488  *           TASK_SpawnTask
 489  *
 490  * Spawn a new 16-bit task.
 491  */
 492 HTASK16 TASK_SpawnTask( NE_MODULE *pModule, WORD cmdShow,
 493                         LPCSTR cmdline, BYTE len, HANDLE *hThread )
 494 {
 495     struct create_data *data = NULL;
 496     WIN16_SUBSYSTEM_TIB *tib;
 497     TDB *pTask;
 498
 499     if (!(pTask = TASK_Create( pModule, cmdShow, cmdline, len ))) return 0;
 500     if (!(tib = allocate_win16_tib( pTask ))) goto failed;
 501     if (!(data = HeapAlloc( GetProcessHeap(), 0, sizeof(*data)))) goto failed;
 502     data->task = pTask;
 503     data->tib = tib;
 504     if (!(*hThread = CreateThread( NULL, 0, task_start, data, 0, NULL ))) goto failed;
 505     return pTask->hSelf;
 506
 507 failed:
 508     if (tib) free_win16_tib( tib );
 509     HeapFree( GetProcessHeap(), 0, data );
 510     TASK_DeleteTask( pTask->hSelf );
 511     return 0;
 512 }
 513
 514
 515 /***********************************************************************
 516  *           TASK_GetTaskFromThread
 517  */
 518 HTASK16 TASK_GetTaskFromThread( DWORD thread )
 519 {
 520     TDB *p = TASK_GetPtr( hFirstTask );
 521     while (p)
 522     {
 523         if (p->teb->ClientId.UniqueThread == (HANDLE)thread) return p->hSelf;
 524         p = TASK_GetPtr( p->hNext );
 525     }
 526     return 0;
 527 }
 528
 529
 530 /***********************************************************************
 531  *           TASK_CallTaskSignalProc
 532  */
 533 static void TASK_CallTaskSignalProc( UINT16 uCode, HANDLE16 hTaskOrModule )
 534 {
 535     WORD args[5];
 536     TDB *pTask = TASK_GetCurrent();
 537
 538     if ( !pTask || !pTask->userhandler ) return;
 539
 540     args[4] = hTaskOrModule;
 541     args[3] = uCode;
 542     args[2] = 0;
 543     args[1] = pTask->hInstance;
 544     args[0] = pTask->hQueue;
 545     WOWCallback16Ex( (DWORD)pTask->userhandler, WCB16_PASCAL, sizeof(args), args, NULL );
 546 }
 547
 548
 549 /***********************************************************************
 550  *           TASK_ExitTask
 551  */
 552 void TASK_ExitTask(void)
 553 {
 554     WIN16_SUBSYSTEM_TIB *tib;
 555     TDB *pTask;
 556     DWORD lockCount;
 557
 558     /* Enter the Win16Lock to protect global data structures */
 559     _EnterWin16Lock();
 560
 561     pTask = TASK_GetCurrent();
 562     if ( !pTask )
 563     {
 564         _LeaveWin16Lock();
 565         return;
 566     }
 567
 568     TRACE("Killing task %04x\n", pTask->hSelf );
 569
 570     /* Perform USER cleanup */
 571
 572     TASK_CallTaskSignalProc( USIG16_TERMINATION, pTask->hSelf );
 573
 574     /* Remove the task from the list to be sure we never switch back to it */
 575     TASK_UnlinkTask( pTask->hSelf );
 576
 577     if (!nTaskCount || (nTaskCount == 1 && hFirstTask == initial_task))
 578     {
 579         TRACE("this is the last task, exiting\n" );
 580         ExitKernel16();
 581     }
 582
 583     pTask->nEvents = 0;
 584
 585     if ( hLockedTask == pTask->hSelf )
 586         hLockedTask = 0;
 587
 588     TASK_DeleteTask( pTask->hSelf );
 589
 590     if ((tib = NtCurrentTeb()->Tib.SubSystemTib))
 591     {
 592         free_win16_tib( tib );
 593         NtCurrentTeb()->Tib.SubSystemTib = NULL;
 594     }
 595
 596     /* ... and completely release the Win16Lock, just in case. */
 597     ReleaseThunkLock( &lockCount );
 598 }
 599
 600
 601 /***********************************************************************
 602  *           ExitKernel (KERNEL.2)
 603  *
 604  * Clean-up everything and exit the Wine process.
 605  */
 606 void WINAPI ExitKernel16(void)
 607 {
 608     WriteOutProfiles16();
 609     TerminateProcess( GetCurrentProcess(), 0 );
 610 }
 611
 612
 613 /***********************************************************************
 614  *           InitTask  (KERNEL.91)
 615  *
 616  * Called by the application startup code.
 617  */
 618 void WINAPI InitTask16( CONTEXT *context )
 619 {
 620     TDB *pTask;
 621     INSTANCEDATA *pinstance;
 622     SEGPTR ptr;
 623
 624     context->Eax = 0;
 625     if (!(pTask = TASK_GetCurrent())) return;
 626
 627     /* Note: we need to trust that BX/CX contain the stack/heap sizes,
 628        as some apps, notably Visual Basic apps, *modify* the heap/stack
 629        size of the instance data segment before calling InitTask() */
 630
 631     /* Initialize the INSTANCEDATA structure */
 632     pinstance = MapSL( MAKESEGPTR(CURRENT_DS, 0) );
 633     pinstance->stackmin    = OFFSETOF(NtCurrentTeb()->WOW32Reserved) + sizeof( STACK16FRAME );
 634     pinstance->stackbottom = pinstance->stackmin; /* yup, that's right. Confused me too. */
 635     pinstance->stacktop    = ( pinstance->stackmin > LOWORD(context->Ebx) ?
 636                                pinstance->stackmin - LOWORD(context->Ebx) : 0 ) + 150;
 637
 638     /* Initialize the local heap */
 639     if (LOWORD(context->Ecx))
 640         LocalInit16( GlobalHandleToSel16(pTask->hInstance), 0, LOWORD(context->Ecx) );
 641
 642     /* Initialize implicitly loaded DLLs */
 643     NE_InitializeDLLs( pTask->hModule );
 644     NE_DllProcessAttach( pTask->hModule );
 645
 646     /* Registers on return are:
 647      * ax     1 if OK, 0 on error
 648      * cx     stack limit in bytes
 649      * dx     cmdShow parameter
 650      * si     instance handle of the previous instance
 651      * di     instance handle of the new task
 652      * es:bx  pointer to command line inside PSP
 653      *
 654      * 0 (=%bp) is pushed on the stack
 655      */
 656     ptr = stack16_push( sizeof(WORD) );
 657     *(WORD *)MapSL(ptr) = 0;
 658     context->Esp -= 2;
 659
 660     context->Eax = 1;
 661
 662     if (!pTask->pdb.cmdLine[0]) context->Ebx = 0x80;
 663     else
 664     {
 665         LPBYTE p = &pTask->pdb.cmdLine[1];
 666         while ((*p == ' ') || (*p == '\t')) p++;
 667         context->Ebx = 0x80 + (p - pTask->pdb.cmdLine);
 668     }
 669     context->Ecx   = pinstance->stacktop;
 670     context->Edx   = pTask->nCmdShow;
 671     context->Esi   = (DWORD)pTask->hPrevInstance;
 672     context->Edi   = (DWORD)pTask->hInstance;
 673     context->SegEs = (WORD)pTask->hPDB;
 674 }
 675
 676
 677 /***********************************************************************
 678  *           WaitEvent  (KERNEL.30)
 679  */
 680 BOOL16 WINAPI WaitEvent16( HTASK16 hTask )
 681 {
 682     TDB *pTask;
 683
 684     if (!hTask) hTask = GetCurrentTask();
 685     pTask = TASK_GetPtr( hTask );
 686
 687     if (pTask->flags & TDBF_WIN32)
 688     {
 689         FIXME("called for Win32 thread (%04x)!\n", GetCurrentThreadId());
 690         return TRUE;
 691     }
 692
 693     if (pTask->nEvents > 0)
 694     {
 695         pTask->nEvents--;
 696         return FALSE;
 697     }
 698
 699     if (pTask->teb == NtCurrentTeb())
 700     {
 701         DWORD lockCount;
 702
 703         NtResetEvent( pTask->hEvent, NULL );
 704         ReleaseThunkLock( &lockCount );
 705         SYSLEVEL_CheckNotLevel( 1 );
 706         WaitForSingleObject( pTask->hEvent, INFINITE );
 707         RestoreThunkLock( lockCount );
 708         if (pTask->nEvents > 0) pTask->nEvents--;
 709     }
 710     else FIXME("for other task %04x cur=%04x\n",pTask->hSelf,GetCurrentTask());
 711
 712     return TRUE;
 713 }
 714
 715
 716 /***********************************************************************
 717  *           PostEvent  (KERNEL.31)
 718  */
 719 void WINAPI PostEvent16( HTASK16 hTask )
 720 {
 721     TDB *pTask;
 722
 723     if (!hTask) hTask = GetCurrentTask();
 724     if (!(pTask = TASK_GetPtr( hTask ))) return;
 725
 726     if (pTask->flags & TDBF_WIN32)
 727     {
 728         FIXME("called for Win32 thread (%04x)!\n", (DWORD)pTask->teb->ClientId.UniqueThread );
 729         return;
 730     }
 731
 732     pTask->nEvents++;
 733
 734     if (pTask->nEvents == 1) NtSetEvent( pTask->hEvent, NULL );
 735 }
 736
 737
 738 /***********************************************************************
 739  *           SetPriority  (KERNEL.32)
 740  */
 741 void WINAPI SetPriority16( HTASK16 hTask, INT16 delta )
 742 {
 743     TDB *pTask;
 744     INT16 newpriority;
 745
 746     if (!hTask) hTask = GetCurrentTask();
 747     if (!(pTask = TASK_GetPtr( hTask ))) return;
 748     newpriority = pTask->priority + delta;
 749     if (newpriority < -32) newpriority = -32;
 750     else if (newpriority > 15) newpriority = 15;
 751
 752     pTask->priority = newpriority + 1;
 753     TASK_UnlinkTask( pTask->hSelf );
 754     TASK_LinkTask( pTask->hSelf );
 755     pTask->priority--;
 756 }
 757
 758
 759 /***********************************************************************
 760  *           LockCurrentTask  (KERNEL.33)
 761  */
 762 HTASK16 WINAPI LockCurrentTask16( BOOL16 bLock )
 763 {
 764     if (bLock) hLockedTask = GetCurrentTask();
 765     else hLockedTask = 0;
 766     return hLockedTask;
 767 }
 768
 769
 770 /***********************************************************************
 771  *           IsTaskLocked  (KERNEL.122)
 772  */
 773 HTASK16 WINAPI IsTaskLocked16(void)
 774 {
 775     return hLockedTask;
 776 }
 777
 778
 779 /***********************************************************************
 780  *           OldYield  (KERNEL.117)
 781  */
 782 void WINAPI OldYield16(void)
 783 {
 784    DWORD count;
 785
 786    ReleaseThunkLock(&count);
 787    RestoreThunkLock(count);
 788 }
 789
 790 /***********************************************************************
 791  *           WIN32_OldYield  (KERNEL.447)
 792  */
 793 void WINAPI WIN32_OldYield16(void)
 794 {
 795    DWORD count;
 796
 797    ReleaseThunkLock(&count);
 798    RestoreThunkLock(count);
 799 }
 800
 801 /***********************************************************************
 802  *           DirectedYield  (KERNEL.150)
 803  */
 804 void WINAPI DirectedYield16( HTASK16 hTask )
 805 {
 806     OldYield16();
 807 }
 808
 809 /***********************************************************************
 810  *           Yield  (KERNEL.29)
 811  */
 812 void WINAPI Yield16(void)
 813 {
 814     TDB *pCurTask = TASK_GetCurrent();
 815
 816     if (pCurTask && pCurTask->hQueue)
 817     {
 818         HMODULE mod = GetModuleHandleA( "user32.dll" );
 819         if (mod)
 820         {
 821             BOOL (WINAPI *pPeekMessageW)( MSG *msg, HWND hwnd, UINT first, UINT last, UINT flags );
 822             pPeekMessageW = (void *)GetProcAddress( mod, "PeekMessageW" );
 823             if (pPeekMessageW)
 824             {
 825                 MSG msg;
 826                 pPeekMessageW( &msg, 0, 0, 0, PM_REMOVE | PM_QS_SENDMESSAGE );
 827                 return;
 828             }
 829         }
 830     }
 831     OldYield16();
 832 }
 833
 834 /***********************************************************************
 835  *           KERNEL_490  (KERNEL.490)
 836  */
 837 HTASK16 WINAPI KERNEL_490( HTASK16 someTask )
 838 {
 839     if ( !someTask ) return 0;
 840
 841     FIXME("(%04x): stub\n", someTask );
 842     return 0;
 843 }
 844
 845 /***********************************************************************
 846  *           MakeProcInstance  (KERNEL.51)
 847  */
 848 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 849 {
 850     struct thunk *thunk;
 851     BYTE *lfunc;
 852     SEGPTR thunkaddr;
 853     WORD hInstanceSelector;
 854
 855     hInstanceSelector = GlobalHandleToSel16(hInstance);
 856
 857     TRACE("(%p, %04x);\n", func, hInstance);
 858
 859     if (!HIWORD(func)) {
 860       /* Win95 actually protects via SEH, but this is better for debugging */
 861       WARN("Ouch ! Called with invalid func %p !\n", func);
 862       return NULL;
 863     }
 864
 865     if ( (GlobalHandleToSel16(CURRENT_DS) != hInstanceSelector)
 866       && (hInstance != 0)
 867       && (hInstance != 0xffff) )
 868     {
 869         /* calling MPI with a foreign DSEG is invalid ! */
 870         WARN("Problem with hInstance? Got %04x, using %04x instead\n",
 871                    hInstance,CURRENT_DS);
 872     }
 873
 874     /* Always use the DSEG that MPI was entered with.
 875      * We used to set hInstance to GetTaskDS16(), but this should be wrong
 876      * as CURRENT_DS provides the DSEG value we need.
 877      * ("calling" DS, *not* "task" DS !) */
 878     hInstanceSelector = CURRENT_DS;
 879     hInstance = GlobalHandle16(hInstanceSelector);
 880
 881     /* no thunking for DLLs */
 882     if (NE_GetPtr(FarGetOwner16(hInstance))->ne_flags & NE_FFLAGS_LIBMODULE)
 883         return func;
 884
 885     thunkaddr = TASK_AllocThunk();
 886     if (!thunkaddr) return NULL;
 887     thunk = MapSL( thunkaddr );
 888     lfunc = MapSL( (SEGPTR)func );
 889
 890     TRACE("(%p,%04x): got thunk %08x\n", func, hInstance, thunkaddr );
 891     if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) || /* movw %ds, %ax */
 892         ((lfunc[0]==0x1e) && (lfunc[1]==0x58))    /* pushw %ds, popw %ax */
 893     ) {
 894         WARN("This was the (in)famous \"thunk useless\" warning. We thought we have to overwrite with nop;nop;, but this isn't true.\n");
 895     }
 896
 897     thunk->movw     = 0xb8;    /* movw instance, %ax */
 898     thunk->instance = hInstanceSelector;
 899     thunk->ljmp     = 0xea;    /* ljmp func */
 900     thunk->func     = func;
 901     return (FARPROC16)thunkaddr;
 902     /* CX reg indicates if thunkaddr != NULL, implement if needed */
 903 }
 904
 905
 906 /***********************************************************************
 907  *           FreeProcInstance  (KERNEL.52)
 908  */
 909 void WINAPI FreeProcInstance16( FARPROC16 func )
 910 {
 911     TRACE("(%p)\n", func );
 912     TASK_FreeThunk( (SEGPTR)func );
 913 }
 914
 915 /**********************************************************************
 916  *          TASK_GetCodeSegment
 917  *
 918  * Helper function for GetCodeHandle/GetCodeInfo: Retrieve the module
 919  * and logical segment number of a given code segment.
 920  *
 921  * 'proc' either *is* already a pair of module handle and segment number,
 922  * in which case there's nothing to do.  Otherwise, it is a pointer to
 923  * a function, and we need to retrieve the code segment.  If the pointer
 924  * happens to point to a thunk, we'll retrieve info about the code segment
 925  * where the function pointed to by the thunk resides, not the thunk itself.
 926  *
 927  * FIXME: if 'proc' is a SNOOP16 return stub, we should retrieve info about
 928  *        the function the snoop code will return to ...
 929  *
 930  */
 931 static BOOL TASK_GetCodeSegment( FARPROC16 proc, NE_MODULE **ppModule,
 932                                  SEGTABLEENTRY **ppSeg, int *pSegNr )
 933 {
 934     NE_MODULE *pModule = NULL;
 935     SEGTABLEENTRY *pSeg = NULL;
 936     int segNr=0;
 937
 938     /* Try pair of module handle / segment number */
 939     pModule = GlobalLock16( HIWORD( proc ) );
 940     if ( pModule && pModule->ne_magic == IMAGE_OS2_SIGNATURE )
 941     {
 942         segNr = LOWORD( proc );
 943         if ( segNr && segNr <= pModule->ne_cseg )
 944             pSeg = NE_SEG_TABLE( pModule ) + segNr-1;
 945     }
 946
 947     /* Try thunk or function */
 948     else
 949     {
 950         BYTE *thunk = MapSL( (SEGPTR)proc );
 951         WORD selector;
 952
 953         if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
 954             selector = thunk[6] + (thunk[7] << 8);
 955         else
 956             selector = HIWORD( proc );
 957
 958         pModule = NE_GetPtr( GlobalHandle16( selector ) );
 959         pSeg = pModule? NE_SEG_TABLE( pModule ) : NULL;
 960
 961         if ( pModule )
 962             for ( segNr = 1; segNr <= pModule->ne_cseg; segNr++, pSeg++ )
 963                 if ( GlobalHandleToSel16(pSeg->hSeg) == selector )
 964                     break;
 965
 966         if ( pModule && segNr > pModule->ne_cseg )
 967             pSeg = NULL;
 968     }
 969
 970     /* Abort if segment not found */
 971
 972     if ( !pModule || !pSeg )
 973         return FALSE;
 974
 975     /* Return segment data */
 976
 977     if ( ppModule ) *ppModule = pModule;
 978     if ( ppSeg    ) *ppSeg    = pSeg;
 979     if ( pSegNr   ) *pSegNr   = segNr;
 980
 981     return TRUE;
 982 }
 983
 984 /**********************************************************************
 985  *          GetCodeHandle    (KERNEL.93)
 986  */
 987 HANDLE16 WINAPI GetCodeHandle16( FARPROC16 proc )
 988 {
 989     SEGTABLEENTRY *pSeg;
 990
 991     if ( !TASK_GetCodeSegment( proc, NULL, &pSeg, NULL ) )
 992         return 0;
 993
 994     return pSeg->hSeg;
 995 }
 996
 997 /**********************************************************************
 998  *          GetCodeInfo    (KERNEL.104)
 999  */
1000 BOOL16 WINAPI GetCodeInfo16( FARPROC16 proc, SEGINFO *segInfo )
1001 {
1002     NE_MODULE *pModule;
1003     SEGTABLEENTRY *pSeg;
1004     int segNr;
1005
1006     if ( !TASK_GetCodeSegment( proc, &pModule, &pSeg, &segNr ) )
1007         return FALSE;
1008
1009     /* Fill in segment information */
1010
1011     segInfo->offSegment = pSeg->filepos;
1012     segInfo->cbSegment  = pSeg->size;
1013     segInfo->flags      = pSeg->flags;
1014     segInfo->cbAlloc    = pSeg->minsize;
1015     segInfo->h          = pSeg->hSeg;
1016     segInfo->alignShift = pModule->ne_align;
1017
1018     if ( segNr == pModule->ne_autodata )
1019         segInfo->cbAlloc += pModule->ne_heap + pModule->ne_stack;
1020
1021     /* Return module handle in %es */
1022
1023     CURRENT_STACK16->es = GlobalHandleToSel16( pModule->self );
1024
1025     return TRUE;
1026 }
1027
1028
1029 /**********************************************************************
1030  *          DefineHandleTable    (KERNEL.94)
1031  */
1032 BOOL16 WINAPI DefineHandleTable16( WORD wOffset )
1033 {
1034     FIXME("(%04x): stub ?\n", wOffset);
1035     return TRUE;
1036 }
1037
1038
1039 /***********************************************************************
1040  *           SetTaskQueue  (KERNEL.34)
1041  */
1042 HQUEUE16 WINAPI SetTaskQueue16( HTASK16 hTask, HQUEUE16 hQueue )
1043 {
1044     FIXME( "stub, should not get called\n" );
1045     return 0xbeef;
1046 }
1047
1048
1049 /***********************************************************************
1050  *           GetTaskQueue  (KERNEL.35)
1051  */
1052 HQUEUE16 WINAPI GetTaskQueue16( HTASK16 hTask )
1053 {
1054     FIXME( "stub, should not get called\n" );
1055     return 0xbeef;
1056 }
1057
1058 /***********************************************************************
1059  *           SetThreadQueue  (KERNEL.463)
1060  */
1061 HQUEUE16 WINAPI SetThreadQueue16( DWORD thread, HQUEUE16 hQueue )
1062 {
1063     FIXME( "stub, should not get called\n" );
1064     return 0xbeef;
1065 }
1066
1067 /***********************************************************************
1068  *           GetThreadQueue  (KERNEL.464)
1069  */
1070 HQUEUE16 WINAPI GetThreadQueue16( DWORD thread )
1071 {
1072     FIXME( "stub, should not get called\n" );
1073     return 0xbeef;
1074 }
1075
1076 /***********************************************************************
1077  *           SetFastQueue  (KERNEL.624)
1078  */
1079 VOID WINAPI SetFastQueue16( DWORD thread, HQUEUE16 hQueue )
1080 {
1081     FIXME( "stub, should not get called\n" );
1082 }
1083
1084 /***********************************************************************
1085  *           GetFastQueue  (KERNEL.625)
1086  */
1087 HQUEUE16 WINAPI GetFastQueue16( void )
1088 {
1089     FIXME( "stub, should not get called\n" );
1090     return 0xbeef;
1091 }
1092
1093 /***********************************************************************
1094  *           SwitchStackTo   (KERNEL.108)
1095  */
1096 void WINAPI SwitchStackTo16( WORD seg, WORD ptr, WORD top )
1097 {
1098     STACK16FRAME *oldFrame, *newFrame;
1099     INSTANCEDATA *pData;
1100     UINT16 copySize;
1101
1102     if (!(pData = GlobalLock16( seg ))) return;
1103     TRACE("old=%04x:%04x new=%04x:%04x\n",
1104           SELECTOROF( NtCurrentTeb()->WOW32Reserved ),
1105           OFFSETOF( NtCurrentTeb()->WOW32Reserved ), seg, ptr );
1106
1107     /* Save the old stack */
1108
1109     oldFrame = CURRENT_STACK16;
1110     /* pop frame + args and push bp */
1111     pData->old_ss_sp   = (SEGPTR)NtCurrentTeb()->WOW32Reserved + sizeof(STACK16FRAME)
1112                            + 2 * sizeof(WORD);
1113     *(WORD *)MapSL(pData->old_ss_sp) = oldFrame->bp;
1114     pData->stacktop    = top;
1115     pData->stackmin    = ptr;
1116     pData->stackbottom = ptr;
1117
1118     /* Switch to the new stack */
1119
1120     /* Note: we need to take the 3 arguments into account; otherwise,
1121      * the stack will underflow upon return from this function.
1122      */
1123     copySize = oldFrame->bp - OFFSETOF(pData->old_ss_sp);
1124     copySize += 3 * sizeof(WORD) + sizeof(STACK16FRAME);
1125     NtCurrentTeb()->WOW32Reserved = (void *)MAKESEGPTR( seg, ptr - copySize );
1126     newFrame = CURRENT_STACK16;
1127
1128     /* Copy the stack frame and the local variables to the new stack */
1129
1130     memmove( newFrame, oldFrame, copySize );
1131     newFrame->bp = ptr;
1132     *(WORD *)MapSL( MAKESEGPTR( seg, ptr ) ) = 0;  /* clear previous bp */
1133 }
1134
1135
1136 /***********************************************************************
1137  *           SwitchStackBack   (KERNEL.109)
1138  */
1139 void WINAPI SwitchStackBack16( CONTEXT *context )
1140 {
1141     STACK16FRAME *oldFrame, *newFrame;
1142     INSTANCEDATA *pData;
1143
1144     if (!(pData = GlobalLock16(SELECTOROF(NtCurrentTeb()->WOW32Reserved))))
1145         return;
1146     if (!pData->old_ss_sp)
1147     {
1148         WARN("No previous SwitchStackTo\n" );
1149         return;
1150     }
1151     TRACE("restoring stack %04x:%04x\n",
1152           SELECTOROF(pData->old_ss_sp), OFFSETOF(pData->old_ss_sp) );
1153
1154     oldFrame = CURRENT_STACK16;
1155
1156     /* Pop bp from the previous stack */
1157
1158     context->Ebp = (context->Ebp & ~0xffff) | *(WORD *)MapSL(pData->old_ss_sp);
1159     pData->old_ss_sp += sizeof(WORD);
1160
1161     /* Switch back to the old stack */
1162
1163     NtCurrentTeb()->WOW32Reserved = (void *)(pData->old_ss_sp - sizeof(STACK16FRAME));
1164     context->SegSs = SELECTOROF(pData->old_ss_sp);
1165     context->Esp   = OFFSETOF(pData->old_ss_sp) - sizeof(DWORD); /*ret addr*/
1166     pData->old_ss_sp = 0;
1167
1168     /* Build a stack frame for the return */
1169
1170     newFrame = CURRENT_STACK16;
1171     newFrame->frame32     = oldFrame->frame32;
1172     newFrame->module_cs   = oldFrame->module_cs;
1173     newFrame->callfrom_ip = oldFrame->callfrom_ip;
1174     newFrame->entry_ip    = oldFrame->entry_ip;
1175 }
1176
1177
1178 /***********************************************************************
1179  *           GetTaskQueueDS  (KERNEL.118)
1180  */
1181 void WINAPI GetTaskQueueDS16(void)
1182 {
1183     CURRENT_STACK16->ds = GlobalHandleToSel16( GetTaskQueue16(0) );
1184 }
1185
1186
1187 /***********************************************************************
1188  *           GetTaskQueueES  (KERNEL.119)
1189  */
1190 void WINAPI GetTaskQueueES16(void)
1191 {
1192     CURRENT_STACK16->es = GlobalHandleToSel16( GetTaskQueue16(0) );
1193 }
1194
1195
1196 /***********************************************************************
1197  *           GetCurrentTask   (KERNEL32.@)
1198  */
1199 HTASK16 WINAPI GetCurrentTask(void)
1200 {
1201     HTASK16 ret = kernel_get_thread_data()->htask16;
1202     if (!ret) ret = main_task;
1203     return ret;
1204 }
1205
1206 /***********************************************************************
1207  *           GetCurrentTask   (KERNEL.36)
1208  */
1209 DWORD WINAPI WIN16_GetCurrentTask(void)
1210 {
1211     /* This is the version used by relay code; the first task is */
1212     /* returned in the high word of the result */
1213     return MAKELONG( GetCurrentTask(), hFirstTask );
1214 }
1215
1216
1217 /***********************************************************************
1218  *           GetCurrentPDB   (KERNEL.37)
1219  *
1220  * UNDOC: returns PSP of KERNEL in high word
1221  */
1222 DWORD WINAPI GetCurrentPDB16(void)
1223 {
1224     TDB *pTask;
1225
1226     if (!(pTask = TASK_GetCurrent())) return 0;
1227     return MAKELONG(pTask->hPDB, 0); /* FIXME */
1228 }
1229
1230
1231 /***********************************************************************
1232  *           GetCurPID   (KERNEL.157)
1233  */
1234 DWORD WINAPI GetCurPID16( DWORD unused )
1235 {
1236     return 0;
1237 }
1238
1239
1240 /***********************************************************************
1241  *           GetInstanceData   (KERNEL.54)
1242  */
1243 INT16 WINAPI GetInstanceData16( HINSTANCE16 instance, WORD buffer, INT16 len )
1244 {
1245     char *ptr = GlobalLock16( instance );
1246     if (!ptr || !len) return 0;
1247     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1248     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1249     return len;
1250 }
1251
1252
1253 /***********************************************************************
1254  *           GetExeVersion   (KERNEL.105)
1255  */
1256 WORD WINAPI GetExeVersion16(void)
1257 {
1258     TDB *pTask;
1259
1260     if (!(pTask = TASK_GetCurrent())) return 0;
1261     return pTask->version;
1262 }
1263
1264
1265 /***********************************************************************
1266  *           SetErrorMode   (KERNEL.107)
1267  */
1268 UINT16 WINAPI SetErrorMode16( UINT16 mode )
1269 {
1270     TDB *pTask;
1271     if (!(pTask = TASK_GetCurrent())) return 0;
1272     pTask->error_mode = mode;
1273     return SetErrorMode( mode );
1274 }
1275
1276
1277 /***********************************************************************
1278  *           GetNumTasks   (KERNEL.152)
1279  */
1280 UINT16 WINAPI GetNumTasks16(void)
1281 {
1282     return nTaskCount;
1283 }
1284
1285
1286 /***********************************************************************
1287  *           GetTaskDS   (KERNEL.155)
1288  *
1289  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1290  * I don't think we need to bother with this.
1291  */
1292 HINSTANCE16 WINAPI GetTaskDS16(void)
1293 {
1294     TDB *pTask;
1295
1296     if (!(pTask = TASK_GetCurrent())) return 0;
1297     return GlobalHandleToSel16(pTask->hInstance);
1298 }
1299
1300 /***********************************************************************
1301  *           GetDummyModuleHandleDS   (KERNEL.602)
1302  */
1303 WORD WINAPI GetDummyModuleHandleDS16(void)
1304 {
1305     TDB *pTask;
1306     WORD selector;
1307
1308     if (!(pTask = TASK_GetCurrent())) return 0;
1309     if (!(pTask->flags & TDBF_WIN32)) return 0;
1310     selector = GlobalHandleToSel16( pTask->hModule );
1311     CURRENT_DS = selector;
1312     return selector;
1313 }
1314
1315 /***********************************************************************
1316  *           IsTask   (KERNEL.320)
1317  */
1318 BOOL16 WINAPI IsTask16( HTASK16 hTask )
1319 {
1320     TDB *pTask;
1321
1322     if (!(pTask = TASK_GetPtr( hTask ))) return FALSE;
1323     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1324     return (pTask->magic == TDB_MAGIC);
1325 }
1326
1327
1328 /***********************************************************************
1329  *           IsWinOldApTask   (KERNEL.158)
1330  */
1331 BOOL16 WINAPI IsWinOldApTask16( HTASK16 hTask )
1332 {
1333     /* should return bit 0 of byte 0x48 in PSP */
1334     return FALSE;
1335 }
1336
1337 /***********************************************************************
1338  *           SetTaskSignalProc   (KERNEL.38)
1339  */
1340 FARPROC16 WINAPI SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1341 {
1342     TDB *pTask;
1343     FARPROC16 oldProc;
1344
1345     if (!hTask) hTask = GetCurrentTask();
1346     if (!(pTask = TASK_GetPtr( hTask ))) return NULL;
1347     oldProc = pTask->userhandler;
1348     pTask->userhandler = proc;
1349     return oldProc;
1350 }
1351
1352 /***********************************************************************
1353  *           SetSigHandler   (KERNEL.140)
1354  */
1355 WORD WINAPI SetSigHandler16( FARPROC16 newhandler, FARPROC16* oldhandler,
1356                            UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1357 {
1358     FIXME("(%p,%p,%p,%d,%d), unimplemented.\n",
1359           newhandler,oldhandler,oldmode,newmode,flag );
1360
1361     if (flag != 1) return 0;
1362     if (!newmode) newhandler = NULL;  /* Default handler */
1363     if (newmode != 4)
1364     {
1365         TDB *pTask;
1366
1367         if (!(pTask = TASK_GetCurrent())) return 0;
1368         if (oldmode) *oldmode = pTask->signal_flags;
1369         pTask->signal_flags = newmode;
1370         if (oldhandler) *oldhandler = pTask->sighandler;
1371         pTask->sighandler = newhandler;
1372     }
1373     return 0;
1374 }
1375
1376
1377 /***********************************************************************
1378  *           GlobalNotify   (KERNEL.154)
1379  *
1380  * Note that GlobalNotify does _not_ return the old NotifyProc
1381  * -- contrary to LocalNotify !!
1382  */
1383 VOID WINAPI GlobalNotify16( FARPROC16 proc )
1384 {
1385     TDB *pTask;
1386
1387     if (!(pTask = TASK_GetCurrent())) return;
1388     pTask->discardhandler = proc;
1389 }
1390
1391
1392 /***********************************************************************
1393  *           GetExePtrHelper
1394  */
1395 static inline HMODULE16 GetExePtrHelper( HANDLE16 handle, HTASK16 *hTask )
1396 {
1397     char *ptr;
1398     HANDLE16 owner;
1399
1400       /* Check for module handle */
1401
1402     if (!(ptr = GlobalLock16( handle ))) return 0;
1403     if (((NE_MODULE *)ptr)->ne_magic == IMAGE_OS2_SIGNATURE) return handle;
1404
1405       /* Search for this handle inside all tasks */
1406
1407     *hTask = hFirstTask;
1408     while (*hTask)
1409     {
1410         TDB *pTask = TASK_GetPtr( *hTask );
1411         if ((*hTask == handle) ||
1412             (pTask->hInstance == handle) ||
1413             (pTask->hQueue == handle) ||
1414             (pTask->hPDB == handle)) return pTask->hModule;
1415         *hTask = pTask->hNext;
1416     }
1417
1418       /* Check the owner for module handle */
1419
1420     owner = FarGetOwner16( handle );
1421     if (!(ptr = GlobalLock16( owner ))) return 0;
1422     if (((NE_MODULE *)ptr)->ne_magic == IMAGE_OS2_SIGNATURE) return owner;
1423
1424       /* Search for the owner inside all tasks */
1425
1426     *hTask = hFirstTask;
1427     while (*hTask)
1428     {
1429         TDB *pTask = TASK_GetPtr( *hTask );
1430         if ((*hTask == owner) ||
1431             (pTask->hInstance == owner) ||
1432             (pTask->hQueue == owner) ||
1433             (pTask->hPDB == owner)) return pTask->hModule;
1434         *hTask = pTask->hNext;
1435     }
1436
1437     return 0;
1438 }
1439
1440 /***********************************************************************
1441  *           GetExePtr   (KERNEL.133)
1442  */
1443 HMODULE16 WINAPI WIN16_GetExePtr( HANDLE16 handle )
1444 {
1445     HTASK16 hTask = 0;
1446     HMODULE16 hModule = GetExePtrHelper( handle, &hTask );
1447     STACK16FRAME *frame = CURRENT_STACK16;
1448     frame->ecx = hModule;
1449     if (hTask) frame->es = hTask;
1450     return hModule;
1451 }
1452
1453
1454 /***********************************************************************
1455  *           K228   (KERNEL.228)
1456  */
1457 HMODULE16 WINAPI GetExePtr( HANDLE16 handle )
1458 {
1459     HTASK16 hTask = 0;
1460     return GetExePtrHelper( handle, &hTask );
1461 }
1462
1463
1464 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND hWnd, LPCSTR text, LPCSTR title, UINT type);
1465
1466 /**************************************************************************
1467  *           FatalAppExit   (KERNEL.137)
1468  */
1469 void WINAPI FatalAppExit16( UINT16 action, LPCSTR str )
1470 {
1471     TDB *pTask = TASK_GetCurrent();
1472
1473     if (!pTask || !(pTask->error_mode & SEM_NOGPFAULTERRORBOX))
1474     {
1475         HMODULE mod = GetModuleHandleA( "user32.dll" );
1476         if (mod)
1477         {
1478             MessageBoxA_funcptr pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
1479             if (pMessageBoxA)
1480             {
1481                 pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
1482                 goto done;
1483             }
1484         }
1485         ERR( "%s\n", debugstr_a(str) );
1486     }
1487  done:
1488     ExitThread(0xff);
1489 }
1490
1491
1492 /***********************************************************************
1493  *           GetAppCompatFlags   (KERNEL.354)
1494  */
1495 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1496 {
1497     TDB *pTask;
1498
1499     if (!hTask) hTask = GetCurrentTask();
1500     if (!(pTask=TASK_GetPtr( hTask ))) return 0;
1501     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1502     return pTask->compat_flags;
1503 }
1504
1505
1506 /***********************************************************************
1507  *           GetDOSEnvironment     (KERNEL.131)
1508  *
1509  * Note: the environment is allocated once, it doesn't track changes
1510  * made using the Win32 API. This shouldn't matter.
1511  *
1512  * Format of a 16-bit environment block:
1513  * ASCIIZ   string 1 (xx=yy format)
1514  * ...
1515  * ASCIIZ   string n
1516  * BYTE     0
1517  * WORD     1
1518  * ASCIIZ   program name (e.g. C:\WINDOWS\SYSTEM\KRNL386.EXE)
1519  */
1520 SEGPTR WINAPI GetDOSEnvironment16(void)
1521 {
1522     static const char ENV_program_name[] = "C:\\WINDOWS\\SYSTEM\\KRNL386.EXE";
1523     static HGLOBAL16 handle;  /* handle to the 16 bit environment */
1524
1525     if (!handle)
1526     {
1527         DWORD size;
1528         LPSTR p, env;
1529
1530         p = env = GetEnvironmentStringsA();
1531         while (*p) p += strlen(p) + 1;
1532         p++;  /* skip last null */
1533         size = (p - env) + sizeof(WORD) + sizeof(ENV_program_name);
1534         handle = GlobalAlloc16( GMEM_FIXED, size );
1535         if (handle)
1536         {
1537             WORD one = 1;
1538             LPSTR env16 = GlobalLock16( handle );
1539             memcpy( env16, env, p - env );
1540             memcpy( env16 + (p - env), &one, sizeof(one));
1541             memcpy( env16 + (p - env) + sizeof(WORD), ENV_program_name, sizeof(ENV_program_name));
1542             GlobalUnlock16( handle );
1543         }
1544         FreeEnvironmentStringsA( env );
1545     }
1546     return WOWGlobalLock16( handle );
1547 }