dlls/kernel32/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 "toolhelp.h"
  42 #include "kernel_private.h"
  43 #include "kernel16_private.h"
  44
  45 #include "wine/debug.h"
  46
  47 WINE_DEFAULT_DEBUG_CHANNEL(task);
  48 WINE_DECLARE_DEBUG_CHANNEL(toolhelp);
  49
  50 #include "pshpack1.h"
  51
  52 struct thunk
  53 {
  54     BYTE      movw;
  55     HANDLE16  instance;
  56     BYTE      ljmp;
  57     FARPROC16 func;
  58 };
  59
  60 /* Segment containing MakeProcInstance() thunks */
  61 typedef struct
  62 {
  63     WORD  next;       /* Selector of next segment */
  64     WORD  magic;      /* Thunks signature */
  65     WORD  unused;
  66     WORD  free;       /* Head of the free list */
  67     struct thunk thunks[1];
  68 } THUNKS;
  69
  70 #include "poppack.h"
  71
  72 #define THUNK_MAGIC  ('P' | ('T' << 8))
  73
  74   /* Min. number of thunks allocated when creating a new segment */
  75 #define MIN_THUNKS  32
  76
  77 #define TDB_MAGIC    ('T' | ('D' << 8))
  78
  79 static THHOOK DefaultThhook;
  80 THHOOK *pThhook = &DefaultThhook;
  81
  82 #define hFirstTask   (pThhook->HeadTDB)
  83 #define hLockedTask  (pThhook->LockTDB)
  84
  85 static UINT16 nTaskCount = 0;
  86
  87 static HTASK16 initial_task, main_task;
  88
  89 /***********************************************************************
  90  *           TASK_InstallTHHook
  91  */
  92 void TASK_InstallTHHook( THHOOK *pNewThhook )
  93 {
  94      THHOOK *pOldThhook = pThhook;
  95
  96      pThhook = pNewThhook? pNewThhook : &DefaultThhook;
  97
  98      *pThhook = *pOldThhook;
  99 }
 100
 101 /***********************************************************************
 102  *           TASK_GetPtr
 103  */
 104 static TDB *TASK_GetPtr( HTASK16 hTask )
 105 {
 106     return GlobalLock16( hTask );
 107 }
 108
 109
 110 /***********************************************************************
 111  *           TASK_GetCurrent
 112  */
 113 TDB *TASK_GetCurrent(void)
 114 {
 115     return TASK_GetPtr( GetCurrentTask() );
 116 }
 117
 118
 119 /***********************************************************************
 120  *           TASK_LinkTask
 121  */
 122 static void TASK_LinkTask( HTASK16 hTask )
 123 {
 124     HTASK16 *prevTask;
 125     TDB *pTask;
 126
 127     if (!(pTask = TASK_GetPtr( hTask ))) return;
 128     prevTask = &hFirstTask;
 129     while (*prevTask)
 130     {
 131         TDB *prevTaskPtr = TASK_GetPtr( *prevTask );
 132         if (prevTaskPtr->priority >= pTask->priority) break;
 133         prevTask = &prevTaskPtr->hNext;
 134     }
 135     pTask->hNext = *prevTask;
 136     *prevTask = hTask;
 137     nTaskCount++;
 138 }
 139
 140
 141 /***********************************************************************
 142  *           TASK_UnlinkTask
 143  */
 144 static void TASK_UnlinkTask( HTASK16 hTask )
 145 {
 146     HTASK16 *prevTask;
 147     TDB *pTask;
 148
 149     prevTask = &hFirstTask;
 150     while (*prevTask && (*prevTask != hTask))
 151     {
 152         pTask = TASK_GetPtr( *prevTask );
 153         prevTask = &pTask->hNext;
 154     }
 155     if (*prevTask)
 156     {
 157         pTask = TASK_GetPtr( *prevTask );
 158         *prevTask = pTask->hNext;
 159         pTask->hNext = 0;
 160         nTaskCount--;
 161     }
 162 }
 163
 164
 165 /***********************************************************************
 166  *           TASK_CreateThunks
 167  *
 168  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 169  * and containing 'count' entries.
 170  */
 171 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 172 {
 173     int i;
 174     THUNKS *pThunk;
 175
 176     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 177     pThunk->next = 0;
 178     pThunk->magic = THUNK_MAGIC;
 179     pThunk->free = FIELD_OFFSET( THUNKS, thunks );
 180     for (i = 0; i < count-1; i++)
 181         *(WORD *)&pThunk->thunks[i] = FIELD_OFFSET( THUNKS, thunks[i+1] );
 182     *(WORD *)&pThunk->thunks[i] = 0;  /* Last thunk */
 183 }
 184
 185
 186 /***********************************************************************
 187  *           TASK_AllocThunk
 188  *
 189  * Allocate a thunk for MakeProcInstance().
 190  */
 191 static SEGPTR TASK_AllocThunk(void)
 192 {
 193     TDB *pTask;
 194     THUNKS *pThunk;
 195     WORD sel, base;
 196
 197     if (!(pTask = TASK_GetCurrent())) return 0;
 198     sel = pTask->hCSAlias;
 199     pThunk = (THUNKS *)pTask->thunks;
 200     base = (char *)pThunk - (char *)pTask;
 201     while (!pThunk->free)
 202     {
 203         sel = pThunk->next;
 204         if (!sel)  /* Allocate a new segment */
 205         {
 206             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 207                                 pTask->hPDB, WINE_LDT_FLAGS_CODE );
 208             if (!sel) return 0;
 209             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 210             pThunk->next = sel;
 211         }
 212         pThunk = (THUNKS *)GlobalLock16( sel );
 213         base = 0;
 214     }
 215     base += pThunk->free;
 216     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 217     return MAKESEGPTR( sel, base );
 218 }
 219
 220
 221 /***********************************************************************
 222  *           TASK_FreeThunk
 223  *
 224  * Free a MakeProcInstance() thunk.
 225  */
 226 static BOOL TASK_FreeThunk( SEGPTR thunk )
 227 {
 228     TDB *pTask;
 229     THUNKS *pThunk;
 230     WORD sel, base;
 231
 232     if (!(pTask = TASK_GetCurrent())) return 0;
 233     sel = pTask->hCSAlias;
 234     pThunk = (THUNKS *)pTask->thunks;
 235     base = (char *)pThunk - (char *)pTask;
 236     while (sel && (sel != HIWORD(thunk)))
 237     {
 238         sel = pThunk->next;
 239         pThunk = (THUNKS *)GlobalLock16( sel );
 240         base = 0;
 241     }
 242     if (!sel) return FALSE;
 243     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 244     pThunk->free = LOWORD(thunk) - base;
 245     return TRUE;
 246 }
 247
 248
 249 /***********************************************************************
 250  *           TASK_Create
 251  *
 252  * NOTE: This routine might be called by a Win32 thread. Thus, we need
 253  *       to be careful to protect global data structures. We do this
 254  *       by entering the Win16Lock while linking the task into the
 255  *       global task list.
 256  */
 257 static TDB *TASK_Create( NE_MODULE *pModule, UINT16 cmdShow, LPCSTR cmdline, BYTE len )
 258 {
 259     HTASK16 hTask;
 260     TDB *pTask;
 261     FARPROC16 proc;
 262     char curdir[MAX_PATH];
 263     HMODULE16 hModule = pModule ? pModule->self : 0;
 264
 265       /* Allocate the task structure */
 266
 267     hTask = GlobalAlloc16( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB) );
 268     if (!hTask) return NULL;
 269     pTask = TASK_GetPtr( hTask );
 270     FarSetOwner16( hTask, hModule );
 271
 272     /* Fill the task structure */
 273
 274     pTask->hSelf = hTask;
 275
 276     pTask->version       = pModule ? pModule->ne_expver : 0x0400;
 277     pTask->hModule       = hModule;
 278     pTask->hParent       = GetCurrentTask();
 279     pTask->magic         = TDB_MAGIC;
 280     pTask->nCmdShow      = cmdShow;
 281
 282     GetCurrentDirectoryA( sizeof(curdir), curdir );
 283     GetShortPathNameA( curdir, curdir, sizeof(curdir) );
 284     pTask->curdrive = (curdir[0] - 'A') | 0x80;
 285     lstrcpynA( pTask->curdir, curdir + 2, sizeof(pTask->curdir) );
 286
 287       /* Create the thunks block */
 288
 289     TASK_CreateThunks( hTask, (char *)pTask->thunks - (char *)pTask, 7 );
 290
 291       /* Copy the module name */
 292
 293     if (hModule)
 294     {
 295         char name[sizeof(pTask->module_name)+1];
 296         size_t len;
 297         GetModuleName16( hModule, name, sizeof(name) );
 298         len = strlen(name) + 1;
 299         memcpy(pTask->module_name, name, min(len,sizeof(pTask->module_name)));
 300         pTask->compat_flags = GetProfileIntA( "Compatibility", name, 0 );
 301     }
 302
 303       /* Allocate a selector for the PDB */
 304
 305     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB16),
 306                                       hModule, WINE_LDT_FLAGS_DATA );
 307
 308       /* Fill the PDB */
 309
 310     pTask->pdb.int20 = 0x20cd;
 311     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 312     proc = GetProcAddress16( GetModuleHandle16("KERNEL"), "DOS3Call" );
 313     memcpy( &pTask->pdb.dispatcher[1], &proc, sizeof(proc) );
 314     pTask->pdb.savedint22 = 0;
 315     pTask->pdb.savedint23 = 0;
 316     pTask->pdb.savedint24 = 0;
 317     pTask->pdb.fileHandlesPtr =
 318         MAKESEGPTR( GlobalHandleToSel16(pTask->hPDB), FIELD_OFFSET( PDB16, fileHandles ));
 319     pTask->pdb.hFileHandles = 0;
 320     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 321     /* FIXME: should we make a copy of the environment? */
 322     pTask->pdb.environment    = SELECTOROF(GetDOSEnvironment16());
 323     pTask->pdb.nbFiles        = 20;
 324
 325     /* Fill the command line */
 326
 327     if (!cmdline)
 328     {
 329         cmdline = GetCommandLineA();
 330         /* remove the first word (program name) */
 331         if (*cmdline == '"')
 332             if (!(cmdline = strchr( cmdline+1, '"' ))) cmdline = GetCommandLineA();
 333         while (*cmdline && (*cmdline != ' ') && (*cmdline != '\t')) cmdline++;
 334         while ((*cmdline == ' ') || (*cmdline == '\t')) cmdline++;
 335         len = strlen(cmdline);
 336     }
 337     if (len >= sizeof(pTask->pdb.cmdLine)) len = sizeof(pTask->pdb.cmdLine)-1;
 338     pTask->pdb.cmdLine[0] = len;
 339     memcpy( pTask->pdb.cmdLine + 1, cmdline, len );
 340     /* pTask->pdb.cmdLine[len+1] = 0; */
 341
 342     TRACE("cmdline='%.*s' task=%04x\n", len, cmdline, hTask );
 343
 344       /* Allocate a code segment alias for the TDB */
 345
 346     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 347                                           sizeof(TDB), pTask->hPDB, WINE_LDT_FLAGS_CODE );
 348
 349       /* Default DTA overwrites command line */
 350
 351     pTask->dta = MAKESEGPTR( pTask->hPDB, FIELD_OFFSET( PDB16, cmdLine ));
 352
 353     /* Create scheduler event for 16-bit tasks */
 354
 355     if ( !(pTask->flags & TDBF_WIN32) )
 356         NtCreateEvent( &pTask->hEvent, EVENT_ALL_ACCESS, NULL, TRUE, FALSE );
 357
 358     if (!initial_task) initial_task = hTask;
 359
 360     return pTask;
 361 }
 362
 363
 364 /***********************************************************************
 365  *           TASK_DeleteTask
 366  */
 367 static void TASK_DeleteTask( HTASK16 hTask )
 368 {
 369     TDB *pTask;
 370     HGLOBAL16 hPDB;
 371
 372     if (!(pTask = TASK_GetPtr( hTask ))) return;
 373     hPDB = pTask->hPDB;
 374
 375     pTask->magic = 0xdead; /* invalidate signature */
 376
 377     /* Free the selector aliases */
 378
 379     GLOBAL_FreeBlock( pTask->hCSAlias );
 380     GLOBAL_FreeBlock( pTask->hPDB );
 381
 382     /* Free the task module */
 383
 384     FreeModule16( pTask->hModule );
 385
 386     /* Free the task structure itself */
 387
 388     GlobalFree16( hTask );
 389
 390     /* Free all memory used by this task (including the 32-bit stack, */
 391     /* the environment block and the thunk segments). */
 392
 393     GlobalFreeAll16( hPDB );
 394 }
 395
 396
 397 /***********************************************************************
 398  *           TASK_CreateMainTask
 399  *
 400  * Create a task for the main (32-bit) process.
 401  */
 402 void TASK_CreateMainTask(void)
 403 {
 404     TDB *pTask;
 405     STARTUPINFOA startup_info;
 406     UINT cmdShow = 1; /* SW_SHOWNORMAL but we don't want to include winuser.h here */
 407
 408     GetStartupInfoA( &startup_info );
 409     if (startup_info.dwFlags & STARTF_USESHOWWINDOW) cmdShow = startup_info.wShowWindow;
 410     pTask = TASK_Create( NULL, cmdShow, NULL, 0 );
 411     if (!pTask)
 412     {
 413         ERR("could not create task for main process\n");
 414         ExitProcess(1);
 415     }
 416
 417     pTask->flags        |= TDBF_WIN32;
 418     pTask->hInstance     = 0;
 419     pTask->hPrevInstance = 0;
 420     pTask->teb           = NtCurrentTeb();
 421
 422     /* Add the task to the linked list */
 423     /* (no need to get the win16 lock, we are the only thread at this point) */
 424     TASK_LinkTask( pTask->hSelf );
 425     main_task = pTask->hSelf;
 426 }
 427
 428
 429 struct create_data
 430 {
 431     TDB                 *task;
 432     WIN16_SUBSYSTEM_TIB *tib;
 433 };
 434
 435 /* allocate the win16 TIB for a new 16-bit task */
 436 static WIN16_SUBSYSTEM_TIB *allocate_win16_tib( TDB *pTask )
 437 {
 438     WCHAR path[MAX_PATH];
 439     WIN16_SUBSYSTEM_TIB *tib;
 440     UNICODE_STRING *curdir;
 441     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 442
 443     if (!(tib = HeapAlloc( GetProcessHeap(), 0, sizeof(*tib) ))) return NULL;
 444     MultiByteToWideChar( CP_ACP, 0, NE_MODULE_NAME(pModule), -1, path, MAX_PATH );
 445     GetLongPathNameW( path, path, MAX_PATH );
 446     if (RtlCreateUnicodeString( &tib->exe_str, path )) tib->exe_name = &tib->exe_str;
 447     else tib->exe_name = NULL;
 448
 449     RtlAcquirePebLock();
 450     if (NtCurrentTeb()->Tib.SubSystemTib)
 451         curdir = &((WIN16_SUBSYSTEM_TIB *)NtCurrentTeb()->Tib.SubSystemTib)->curdir.DosPath;
 452     else
 453         curdir = &NtCurrentTeb()->Peb->ProcessParameters->CurrentDirectory.DosPath;
 454     tib->curdir.DosPath.MaximumLength = sizeof(tib->curdir_buffer);
 455     tib->curdir.DosPath.Length = min( curdir->Length, tib->curdir.DosPath.MaximumLength-sizeof(WCHAR) );
 456     tib->curdir.DosPath.Buffer = tib->curdir_buffer;
 457     tib->curdir.Handle = 0;
 458     memcpy( tib->curdir_buffer, curdir->Buffer, tib->curdir.DosPath.Length );
 459     tib->curdir_buffer[tib->curdir.DosPath.Length/sizeof(WCHAR)] = 0;
 460     RtlReleasePebLock();
 461     return tib;
 462 }
 463
 464 static inline void free_win16_tib( WIN16_SUBSYSTEM_TIB *tib )
 465 {
 466     if (tib->exe_name) RtlFreeUnicodeString( tib->exe_name );
 467     HeapFree( GetProcessHeap(), 0, tib );
 468 }
 469
 470 /* startup routine for a new 16-bit thread */
 471 static DWORD CALLBACK task_start( LPVOID p )
 472 {
 473     struct create_data *data = p;
 474     TDB *pTask = data->task;
 475     DWORD ret;
 476
 477     kernel_get_thread_data()->htask16 = pTask->hSelf;
 478     NtCurrentTeb()->Tib.SubSystemTib = data->tib;
 479     HeapFree( GetProcessHeap(), 0, data );
 480
 481     _EnterWin16Lock();
 482     TASK_LinkTask( pTask->hSelf );
 483     pTask->teb = NtCurrentTeb();
 484     ret = NE_StartTask();
 485     _LeaveWin16Lock();
 486     return ret;
 487 }
 488
 489
 490 /***********************************************************************
 491  *           TASK_SpawnTask
 492  *
 493  * Spawn a new 16-bit task.
 494  */
 495 HTASK16 TASK_SpawnTask( NE_MODULE *pModule, WORD cmdShow,
 496                         LPCSTR cmdline, BYTE len, HANDLE *hThread )
 497 {
 498     struct create_data *data = NULL;
 499     WIN16_SUBSYSTEM_TIB *tib;
 500     TDB *pTask;
 501
 502     if (!(pTask = TASK_Create( pModule, cmdShow, cmdline, len ))) return 0;
 503     if (!(tib = allocate_win16_tib( pTask ))) goto failed;
 504     if (!(data = HeapAlloc( GetProcessHeap(), 0, sizeof(*data)))) goto failed;
 505     data->task = pTask;
 506     data->tib = tib;
 507     if (!(*hThread = CreateThread( NULL, 0, task_start, data, 0, NULL ))) goto failed;
 508     return pTask->hSelf;
 509
 510 failed:
 511     if (tib) free_win16_tib( tib );
 512     HeapFree( GetProcessHeap(), 0, data );
 513     TASK_DeleteTask( pTask->hSelf );
 514     return 0;
 515 }
 516
 517
 518 /***********************************************************************
 519  *           TASK_GetTaskFromThread
 520  */
 521 HTASK16 TASK_GetTaskFromThread( DWORD thread )
 522 {
 523     TDB *p = TASK_GetPtr( hFirstTask );
 524     while (p)
 525     {
 526         if (p->teb->ClientId.UniqueThread == (HANDLE)thread) return p->hSelf;
 527         p = TASK_GetPtr( p->hNext );
 528     }
 529     return 0;
 530 }
 531
 532
 533 /***********************************************************************
 534  *           TASK_CallTaskSignalProc
 535  */
 536 static void TASK_CallTaskSignalProc( UINT16 uCode, HANDLE16 hTaskOrModule )
 537 {
 538     WORD args[5];
 539     TDB *pTask = TASK_GetCurrent();
 540
 541     if ( !pTask || !pTask->userhandler ) return;
 542
 543     args[4] = hTaskOrModule;
 544     args[3] = uCode;
 545     args[2] = 0;
 546     args[1] = pTask->hInstance;
 547     args[0] = pTask->hQueue;
 548     WOWCallback16Ex( (DWORD)pTask->userhandler, WCB16_PASCAL, sizeof(args), args, NULL );
 549 }
 550
 551
 552 /***********************************************************************
 553  *           TASK_ExitTask
 554  */
 555 void TASK_ExitTask(void)
 556 {
 557     WIN16_SUBSYSTEM_TIB *tib;
 558     TDB *pTask;
 559     DWORD lockCount;
 560
 561     /* Enter the Win16Lock to protect global data structures */
 562     _EnterWin16Lock();
 563
 564     pTask = TASK_GetCurrent();
 565     if ( !pTask )
 566     {
 567         _LeaveWin16Lock();
 568         return;
 569     }
 570
 571     TRACE("Killing task %04x\n", pTask->hSelf );
 572
 573     /* Perform USER cleanup */
 574
 575     TASK_CallTaskSignalProc( USIG16_TERMINATION, pTask->hSelf );
 576
 577     /* Remove the task from the list to be sure we never switch back to it */
 578     TASK_UnlinkTask( pTask->hSelf );
 579
 580     if (!nTaskCount || (nTaskCount == 1 && hFirstTask == initial_task))
 581     {
 582         TRACE("this is the last task, exiting\n" );
 583         ExitKernel16();
 584     }
 585
 586     pTask->nEvents = 0;
 587
 588     if ( hLockedTask == pTask->hSelf )
 589         hLockedTask = 0;
 590
 591     TASK_DeleteTask( pTask->hSelf );
 592
 593     if ((tib = NtCurrentTeb()->Tib.SubSystemTib))
 594     {
 595         free_win16_tib( tib );
 596         NtCurrentTeb()->Tib.SubSystemTib = NULL;
 597     }
 598
 599     /* ... and completely release the Win16Lock, just in case. */
 600     ReleaseThunkLock( &lockCount );
 601 }
 602
 603
 604 /***********************************************************************
 605  *           ExitKernel (KERNEL.2)
 606  *
 607  * Clean-up everything and exit the Wine process.
 608  */
 609 void WINAPI ExitKernel16(void)
 610 {
 611     WriteOutProfiles16();
 612     TerminateProcess( GetCurrentProcess(), 0 );
 613 }
 614
 615
 616 /***********************************************************************
 617  *           InitTask  (KERNEL.91)
 618  *
 619  * Called by the application startup code.
 620  */
 621 void WINAPI InitTask16( CONTEXT86 *context )
 622 {
 623     TDB *pTask;
 624     INSTANCEDATA *pinstance;
 625     SEGPTR ptr;
 626
 627     context->Eax = 0;
 628     if (!(pTask = TASK_GetCurrent())) return;
 629
 630     /* Note: we need to trust that BX/CX contain the stack/heap sizes,
 631        as some apps, notably Visual Basic apps, *modify* the heap/stack
 632        size of the instance data segment before calling InitTask() */
 633
 634     /* Initialize the INSTANCEDATA structure */
 635     pinstance = MapSL( MAKESEGPTR(CURRENT_DS, 0) );
 636     pinstance->stackmin    = OFFSETOF(NtCurrentTeb()->WOW32Reserved) + sizeof( STACK16FRAME );
 637     pinstance->stackbottom = pinstance->stackmin; /* yup, that's right. Confused me too. */
 638     pinstance->stacktop    = ( pinstance->stackmin > LOWORD(context->Ebx) ?
 639                                pinstance->stackmin - LOWORD(context->Ebx) : 0 ) + 150;
 640
 641     /* Initialize the local heap */
 642     if (LOWORD(context->Ecx))
 643         LocalInit16( GlobalHandleToSel16(pTask->hInstance), 0, LOWORD(context->Ecx) );
 644
 645     /* Initialize implicitly loaded DLLs */
 646     NE_InitializeDLLs( pTask->hModule );
 647     NE_DllProcessAttach( pTask->hModule );
 648
 649     /* Registers on return are:
 650      * ax     1 if OK, 0 on error
 651      * cx     stack limit in bytes
 652      * dx     cmdShow parameter
 653      * si     instance handle of the previous instance
 654      * di     instance handle of the new task
 655      * es:bx  pointer to command line inside PSP
 656      *
 657      * 0 (=%bp) is pushed on the stack
 658      */
 659     ptr = stack16_push( sizeof(WORD) );
 660     *(WORD *)MapSL(ptr) = 0;
 661     context->Esp -= 2;
 662
 663     context->Eax = 1;
 664
 665     if (!pTask->pdb.cmdLine[0]) context->Ebx = 0x80;
 666     else
 667     {
 668         LPBYTE p = &pTask->pdb.cmdLine[1];
 669         while ((*p == ' ') || (*p == '\t')) p++;
 670         context->Ebx = 0x80 + (p - pTask->pdb.cmdLine);
 671     }
 672     context->Ecx   = pinstance->stacktop;
 673     context->Edx   = pTask->nCmdShow;
 674     context->Esi   = (DWORD)pTask->hPrevInstance;
 675     context->Edi   = (DWORD)pTask->hInstance;
 676     context->SegEs = (WORD)pTask->hPDB;
 677 }
 678
 679
 680 /***********************************************************************
 681  *           WaitEvent  (KERNEL.30)
 682  */
 683 BOOL16 WINAPI WaitEvent16( HTASK16 hTask )
 684 {
 685     TDB *pTask;
 686
 687     if (!hTask) hTask = GetCurrentTask();
 688     pTask = TASK_GetPtr( hTask );
 689
 690     if (pTask->flags & TDBF_WIN32)
 691     {
 692         FIXME("called for Win32 thread (%04x)!\n", GetCurrentThreadId());
 693         return TRUE;
 694     }
 695
 696     if (pTask->nEvents > 0)
 697     {
 698         pTask->nEvents--;
 699         return FALSE;
 700     }
 701
 702     if (pTask->teb == NtCurrentTeb())
 703     {
 704         DWORD lockCount;
 705
 706         NtResetEvent( pTask->hEvent, NULL );
 707         ReleaseThunkLock( &lockCount );
 708         SYSLEVEL_CheckNotLevel( 1 );
 709         WaitForSingleObject( pTask->hEvent, INFINITE );
 710         RestoreThunkLock( lockCount );
 711         if (pTask->nEvents > 0) pTask->nEvents--;
 712     }
 713     else FIXME("for other task %04x cur=%04x\n",pTask->hSelf,GetCurrentTask());
 714
 715     return TRUE;
 716 }
 717
 718
 719 /***********************************************************************
 720  *           PostEvent  (KERNEL.31)
 721  */
 722 void WINAPI PostEvent16( HTASK16 hTask )
 723 {
 724     TDB *pTask;
 725
 726     if (!hTask) hTask = GetCurrentTask();
 727     if (!(pTask = TASK_GetPtr( hTask ))) return;
 728
 729     if (pTask->flags & TDBF_WIN32)
 730     {
 731         FIXME("called for Win32 thread (%04x)!\n", (DWORD)pTask->teb->ClientId.UniqueThread );
 732         return;
 733     }
 734
 735     pTask->nEvents++;
 736
 737     if (pTask->nEvents == 1) NtSetEvent( pTask->hEvent, NULL );
 738 }
 739
 740
 741 /***********************************************************************
 742  *           SetPriority  (KERNEL.32)
 743  */
 744 void WINAPI SetPriority16( HTASK16 hTask, INT16 delta )
 745 {
 746     TDB *pTask;
 747     INT16 newpriority;
 748
 749     if (!hTask) hTask = GetCurrentTask();
 750     if (!(pTask = TASK_GetPtr( hTask ))) return;
 751     newpriority = pTask->priority + delta;
 752     if (newpriority < -32) newpriority = -32;
 753     else if (newpriority > 15) newpriority = 15;
 754
 755     pTask->priority = newpriority + 1;
 756     TASK_UnlinkTask( pTask->hSelf );
 757     TASK_LinkTask( pTask->hSelf );
 758     pTask->priority--;
 759 }
 760
 761
 762 /***********************************************************************
 763  *           LockCurrentTask  (KERNEL.33)
 764  */
 765 HTASK16 WINAPI LockCurrentTask16( BOOL16 bLock )
 766 {
 767     if (bLock) hLockedTask = GetCurrentTask();
 768     else hLockedTask = 0;
 769     return hLockedTask;
 770 }
 771
 772
 773 /***********************************************************************
 774  *           IsTaskLocked  (KERNEL.122)
 775  */
 776 HTASK16 WINAPI IsTaskLocked16(void)
 777 {
 778     return hLockedTask;
 779 }
 780
 781
 782 /***********************************************************************
 783  *           OldYield  (KERNEL.117)
 784  */
 785 void WINAPI OldYield16(void)
 786 {
 787    DWORD count;
 788
 789    ReleaseThunkLock(&count);
 790    RestoreThunkLock(count);
 791 }
 792
 793 /***********************************************************************
 794  *           WIN32_OldYield  (KERNEL.447)
 795  */
 796 void WINAPI WIN32_OldYield16(void)
 797 {
 798    DWORD count;
 799
 800    ReleaseThunkLock(&count);
 801    RestoreThunkLock(count);
 802 }
 803
 804 /***********************************************************************
 805  *           DirectedYield  (KERNEL.150)
 806  */
 807 void WINAPI DirectedYield16( HTASK16 hTask )
 808 {
 809     OldYield16();
 810 }
 811
 812 /***********************************************************************
 813  *           Yield  (KERNEL.29)
 814  */
 815 void WINAPI Yield16(void)
 816 {
 817     TDB *pCurTask = TASK_GetCurrent();
 818
 819     if (pCurTask && pCurTask->hQueue)
 820     {
 821         HMODULE mod = GetModuleHandleA( "user32.dll" );
 822         if (mod)
 823         {
 824             FARPROC proc = GetProcAddress( mod, "UserYield16" );
 825             if (proc)
 826             {
 827                 proc();
 828                 return;
 829             }
 830         }
 831     }
 832     OldYield16();
 833 }
 834
 835 /***********************************************************************
 836  *           KERNEL_490  (KERNEL.490)
 837  */
 838 HTASK16 WINAPI KERNEL_490( HTASK16 someTask )
 839 {
 840     if ( !someTask ) return 0;
 841
 842     FIXME("(%04x): stub\n", someTask );
 843     return 0;
 844 }
 845
 846 /***********************************************************************
 847  *           MakeProcInstance  (KERNEL.51)
 848  */
 849 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 850 {
 851     struct thunk *thunk;
 852     BYTE *lfunc;
 853     SEGPTR thunkaddr;
 854     WORD hInstanceSelector;
 855
 856     hInstanceSelector = GlobalHandleToSel16(hInstance);
 857
 858     TRACE("(%p, %04x);\n", func, hInstance);
 859
 860     if (!HIWORD(func)) {
 861       /* Win95 actually protects via SEH, but this is better for debugging */
 862       WARN("Ouch ! Called with invalid func %p !\n", func);
 863       return NULL;
 864     }
 865
 866     if ( (GlobalHandleToSel16(CURRENT_DS) != hInstanceSelector)
 867       && (hInstance != 0)
 868       && (hInstance != 0xffff) )
 869     {
 870         /* calling MPI with a foreign DSEG is invalid ! */
 871         WARN("Problem with hInstance? Got %04x, using %04x instead\n",
 872                    hInstance,CURRENT_DS);
 873     }
 874
 875     /* Always use the DSEG that MPI was entered with.
 876      * We used to set hInstance to GetTaskDS16(), but this should be wrong
 877      * as CURRENT_DS provides the DSEG value we need.
 878      * ("calling" DS, *not* "task" DS !) */
 879     hInstanceSelector = CURRENT_DS;
 880     hInstance = GlobalHandle16(hInstanceSelector);
 881
 882     /* no thunking for DLLs */
 883     if (NE_GetPtr(FarGetOwner16(hInstance))->ne_flags & NE_FFLAGS_LIBMODULE)
 884         return func;
 885
 886     thunkaddr = TASK_AllocThunk();
 887     if (!thunkaddr) return NULL;
 888     thunk = MapSL( thunkaddr );
 889     lfunc = MapSL( (SEGPTR)func );
 890
 891     TRACE("(%p,%04x): got thunk %08x\n", func, hInstance, thunkaddr );
 892     if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) || /* movw %ds, %ax */
 893         ((lfunc[0]==0x1e) && (lfunc[1]==0x58))    /* pushw %ds, popw %ax */
 894     ) {
 895         WARN("This was the (in)famous \"thunk useless\" warning. We thought we have to overwrite with nop;nop;, but this isn't true.\n");
 896     }
 897
 898     thunk->movw     = 0xb8;    /* movw instance, %ax */
 899     thunk->instance = hInstanceSelector;
 900     thunk->ljmp     = 0xea;    /* ljmp func */
 901     thunk->func     = func;
 902     return (FARPROC16)thunkaddr;
 903     /* CX reg indicates if thunkaddr != NULL, implement if needed */
 904 }
 905
 906
 907 /***********************************************************************
 908  *           FreeProcInstance  (KERNEL.52)
 909  */
 910 void WINAPI FreeProcInstance16( FARPROC16 func )
 911 {
 912     TRACE("(%p)\n", func );
 913     TASK_FreeThunk( (SEGPTR)func );
 914 }
 915
 916 /**********************************************************************
 917  *          TASK_GetCodeSegment
 918  *
 919  * Helper function for GetCodeHandle/GetCodeInfo: Retrieve the module
 920  * and logical segment number of a given code segment.
 921  *
 922  * 'proc' either *is* already a pair of module handle and segment number,
 923  * in which case there's nothing to do.  Otherwise, it is a pointer to
 924  * a function, and we need to retrieve the code segment.  If the pointer
 925  * happens to point to a thunk, we'll retrieve info about the code segment
 926  * where the function pointed to by the thunk resides, not the thunk itself.
 927  *
 928  * FIXME: if 'proc' is a SNOOP16 return stub, we should retrieve info about
 929  *        the function the snoop code will return to ...
 930  *
 931  */
 932 static BOOL TASK_GetCodeSegment( FARPROC16 proc, NE_MODULE **ppModule,
 933                                  SEGTABLEENTRY **ppSeg, int *pSegNr )
 934 {
 935     NE_MODULE *pModule = NULL;
 936     SEGTABLEENTRY *pSeg = NULL;
 937     int segNr=0;
 938
 939     /* Try pair of module handle / segment number */
 940     pModule = (NE_MODULE *) GlobalLock16( HIWORD( proc ) );
 941     if ( pModule && pModule->ne_magic == IMAGE_OS2_SIGNATURE )
 942     {
 943         segNr = LOWORD( proc );
 944         if ( segNr && segNr <= pModule->ne_cseg )
 945             pSeg = NE_SEG_TABLE( pModule ) + segNr-1;
 946     }
 947
 948     /* Try thunk or function */
 949     else
 950     {
 951         BYTE *thunk = MapSL( (SEGPTR)proc );
 952         WORD selector;
 953
 954         if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
 955             selector = thunk[6] + (thunk[7] << 8);
 956         else
 957             selector = HIWORD( proc );
 958
 959         pModule = NE_GetPtr( GlobalHandle16( selector ) );
 960         pSeg = pModule? NE_SEG_TABLE( pModule ) : NULL;
 961
 962         if ( pModule )
 963             for ( segNr = 1; segNr <= pModule->ne_cseg; segNr++, pSeg++ )
 964                 if ( GlobalHandleToSel16(pSeg->hSeg) == selector )
 965                     break;
 966
 967         if ( pModule && segNr > pModule->ne_cseg )
 968             pSeg = NULL;
 969     }
 970
 971     /* Abort if segment not found */
 972
 973     if ( !pModule || !pSeg )
 974         return FALSE;
 975
 976     /* Return segment data */
 977
 978     if ( ppModule ) *ppModule = pModule;
 979     if ( ppSeg    ) *ppSeg    = pSeg;
 980     if ( pSegNr   ) *pSegNr   = segNr;
 981
 982     return TRUE;
 983 }
 984
 985 /**********************************************************************
 986  *          GetCodeHandle    (KERNEL.93)
 987  */
 988 HANDLE16 WINAPI GetCodeHandle16( FARPROC16 proc )
 989 {
 990     SEGTABLEENTRY *pSeg;
 991
 992     if ( !TASK_GetCodeSegment( proc, NULL, &pSeg, NULL ) )
 993         return 0;
 994
 995     return pSeg->hSeg;
 996 }
 997
 998 /**********************************************************************
 999  *          GetCodeInfo    (KERNEL.104)
1000  */
1001 BOOL16 WINAPI GetCodeInfo16( FARPROC16 proc, SEGINFO *segInfo )
1002 {
1003     NE_MODULE *pModule;
1004     SEGTABLEENTRY *pSeg;
1005     int segNr;
1006
1007     if ( !TASK_GetCodeSegment( proc, &pModule, &pSeg, &segNr ) )
1008         return FALSE;
1009
1010     /* Fill in segment information */
1011
1012     segInfo->offSegment = pSeg->filepos;
1013     segInfo->cbSegment  = pSeg->size;
1014     segInfo->flags      = pSeg->flags;
1015     segInfo->cbAlloc    = pSeg->minsize;
1016     segInfo->h          = pSeg->hSeg;
1017     segInfo->alignShift = pModule->ne_align;
1018
1019     if ( segNr == pModule->ne_autodata )
1020         segInfo->cbAlloc += pModule->ne_heap + pModule->ne_stack;
1021
1022     /* Return module handle in %es */
1023
1024     CURRENT_STACK16->es = GlobalHandleToSel16( pModule->self );
1025
1026     return TRUE;
1027 }
1028
1029
1030 /**********************************************************************
1031  *          DefineHandleTable    (KERNEL.94)
1032  */
1033 BOOL16 WINAPI DefineHandleTable16( WORD wOffset )
1034 {
1035     FIXME("(%04x): stub ?\n", wOffset);
1036     return TRUE;
1037 }
1038
1039
1040 /***********************************************************************
1041  *           SetTaskQueue  (KERNEL.34)
1042  */
1043 HQUEUE16 WINAPI SetTaskQueue16( HTASK16 hTask, HQUEUE16 hQueue )
1044 {
1045     FIXME( "stub, should not get called\n" );
1046     return 0xbeef;
1047 }
1048
1049
1050 /***********************************************************************
1051  *           GetTaskQueue  (KERNEL.35)
1052  */
1053 HQUEUE16 WINAPI GetTaskQueue16( HTASK16 hTask )
1054 {
1055     FIXME( "stub, should not get called\n" );
1056     return 0xbeef;
1057 }
1058
1059 /***********************************************************************
1060  *           SetThreadQueue  (KERNEL.463)
1061  */
1062 HQUEUE16 WINAPI SetThreadQueue16( DWORD thread, HQUEUE16 hQueue )
1063 {
1064     FIXME( "stub, should not get called\n" );
1065     return 0xbeef;
1066 }
1067
1068 /***********************************************************************
1069  *           GetThreadQueue  (KERNEL.464)
1070  */
1071 HQUEUE16 WINAPI GetThreadQueue16( DWORD thread )
1072 {
1073     FIXME( "stub, should not get called\n" );
1074     return 0xbeef;
1075 }
1076
1077 /***********************************************************************
1078  *           SetFastQueue  (KERNEL.624)
1079  */
1080 VOID WINAPI SetFastQueue16( DWORD thread, HQUEUE16 hQueue )
1081 {
1082     FIXME( "stub, should not get called\n" );
1083 }
1084
1085 /***********************************************************************
1086  *           GetFastQueue  (KERNEL.625)
1087  */
1088 HQUEUE16 WINAPI GetFastQueue16( void )
1089 {
1090     FIXME( "stub, should not get called\n" );
1091     return 0xbeef;
1092 }
1093
1094 /***********************************************************************
1095  *           SwitchStackTo   (KERNEL.108)
1096  */
1097 void WINAPI SwitchStackTo16( WORD seg, WORD ptr, WORD top )
1098 {
1099     STACK16FRAME *oldFrame, *newFrame;
1100     INSTANCEDATA *pData;
1101     UINT16 copySize;
1102
1103     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
1104     TRACE("old=%04x:%04x new=%04x:%04x\n",
1105           SELECTOROF( NtCurrentTeb()->WOW32Reserved ),
1106           OFFSETOF( NtCurrentTeb()->WOW32Reserved ), seg, ptr );
1107
1108     /* Save the old stack */
1109
1110     oldFrame = CURRENT_STACK16;
1111     /* pop frame + args and push bp */
1112     pData->old_ss_sp   = (SEGPTR)NtCurrentTeb()->WOW32Reserved + sizeof(STACK16FRAME)
1113                            + 2 * sizeof(WORD);
1114     *(WORD *)MapSL(pData->old_ss_sp) = oldFrame->bp;
1115     pData->stacktop    = top;
1116     pData->stackmin    = ptr;
1117     pData->stackbottom = ptr;
1118
1119     /* Switch to the new stack */
1120
1121     /* Note: we need to take the 3 arguments into account; otherwise,
1122      * the stack will underflow upon return from this function.
1123      */
1124     copySize = oldFrame->bp - OFFSETOF(pData->old_ss_sp);
1125     copySize += 3 * sizeof(WORD) + sizeof(STACK16FRAME);
1126     NtCurrentTeb()->WOW32Reserved = (void *)MAKESEGPTR( seg, ptr - copySize );
1127     newFrame = CURRENT_STACK16;
1128
1129     /* Copy the stack frame and the local variables to the new stack */
1130
1131     memmove( newFrame, oldFrame, copySize );
1132     newFrame->bp = ptr;
1133     *(WORD *)MapSL( MAKESEGPTR( seg, ptr ) ) = 0;  /* clear previous bp */
1134 }
1135
1136
1137 /***********************************************************************
1138  *           SwitchStackBack   (KERNEL.109)
1139  */
1140 void WINAPI SwitchStackBack16( CONTEXT86 *context )
1141 {
1142     STACK16FRAME *oldFrame, *newFrame;
1143     INSTANCEDATA *pData;
1144
1145     if (!(pData = (INSTANCEDATA *)GlobalLock16(SELECTOROF(NtCurrentTeb()->WOW32Reserved))))
1146         return;
1147     if (!pData->old_ss_sp)
1148     {
1149         WARN("No previous SwitchStackTo\n" );
1150         return;
1151     }
1152     TRACE("restoring stack %04x:%04x\n",
1153           SELECTOROF(pData->old_ss_sp), OFFSETOF(pData->old_ss_sp) );
1154
1155     oldFrame = CURRENT_STACK16;
1156
1157     /* Pop bp from the previous stack */
1158
1159     context->Ebp = (context->Ebp & ~0xffff) | *(WORD *)MapSL(pData->old_ss_sp);
1160     pData->old_ss_sp += sizeof(WORD);
1161
1162     /* Switch back to the old stack */
1163
1164     NtCurrentTeb()->WOW32Reserved = (void *)(pData->old_ss_sp - sizeof(STACK16FRAME));
1165     context->SegSs = SELECTOROF(pData->old_ss_sp);
1166     context->Esp   = OFFSETOF(pData->old_ss_sp) - sizeof(DWORD); /*ret addr*/
1167     pData->old_ss_sp = 0;
1168
1169     /* Build a stack frame for the return */
1170
1171     newFrame = CURRENT_STACK16;
1172     newFrame->frame32     = oldFrame->frame32;
1173     newFrame->module_cs   = oldFrame->module_cs;
1174     newFrame->callfrom_ip = oldFrame->callfrom_ip;
1175     newFrame->entry_ip    = oldFrame->entry_ip;
1176 }
1177
1178
1179 /***********************************************************************
1180  *           GetTaskQueueDS  (KERNEL.118)
1181  */
1182 void WINAPI GetTaskQueueDS16(void)
1183 {
1184     CURRENT_STACK16->ds = GlobalHandleToSel16( GetTaskQueue16(0) );
1185 }
1186
1187
1188 /***********************************************************************
1189  *           GetTaskQueueES  (KERNEL.119)
1190  */
1191 void WINAPI GetTaskQueueES16(void)
1192 {
1193     CURRENT_STACK16->es = GlobalHandleToSel16( GetTaskQueue16(0) );
1194 }
1195
1196
1197 /***********************************************************************
1198  *           GetCurrentTask   (KERNEL32.@)
1199  */
1200 HTASK16 WINAPI GetCurrentTask(void)
1201 {
1202     HTASK16 ret = kernel_get_thread_data()->htask16;
1203     if (!ret) ret = main_task;
1204     return ret;
1205 }
1206
1207 /***********************************************************************
1208  *           GetCurrentTask   (KERNEL.36)
1209  */
1210 DWORD WINAPI WIN16_GetCurrentTask(void)
1211 {
1212     /* This is the version used by relay code; the first task is */
1213     /* returned in the high word of the result */
1214     return MAKELONG( GetCurrentTask(), hFirstTask );
1215 }
1216
1217
1218 /***********************************************************************
1219  *           GetCurrentPDB   (KERNEL.37)
1220  *
1221  * UNDOC: returns PSP of KERNEL in high word
1222  */
1223 DWORD WINAPI GetCurrentPDB16(void)
1224 {
1225     TDB *pTask;
1226
1227     if (!(pTask = TASK_GetCurrent())) return 0;
1228     return MAKELONG(pTask->hPDB, 0); /* FIXME */
1229 }
1230
1231
1232 /***********************************************************************
1233  *           GetCurPID   (KERNEL.157)
1234  */
1235 DWORD WINAPI GetCurPID16( DWORD unused )
1236 {
1237     return 0;
1238 }
1239
1240
1241 /***********************************************************************
1242  *           GetInstanceData   (KERNEL.54)
1243  */
1244 INT16 WINAPI GetInstanceData16( HINSTANCE16 instance, WORD buffer, INT16 len )
1245 {
1246     char *ptr = (char *)GlobalLock16( instance );
1247     if (!ptr || !len) return 0;
1248     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1249     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1250     return len;
1251 }
1252
1253
1254 /***********************************************************************
1255  *           GetExeVersion   (KERNEL.105)
1256  */
1257 WORD WINAPI GetExeVersion16(void)
1258 {
1259     TDB *pTask;
1260
1261     if (!(pTask = TASK_GetCurrent())) return 0;
1262     return pTask->version;
1263 }
1264
1265
1266 /***********************************************************************
1267  *           SetErrorMode   (KERNEL.107)
1268  */
1269 UINT16 WINAPI SetErrorMode16( UINT16 mode )
1270 {
1271     TDB *pTask;
1272     if (!(pTask = TASK_GetCurrent())) return 0;
1273     pTask->error_mode = mode;
1274     return SetErrorMode( mode );
1275 }
1276
1277
1278 /***********************************************************************
1279  *           GetNumTasks   (KERNEL.152)
1280  */
1281 UINT16 WINAPI GetNumTasks16(void)
1282 {
1283     return nTaskCount;
1284 }
1285
1286
1287 /***********************************************************************
1288  *           GetTaskDS   (KERNEL.155)
1289  *
1290  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1291  * I don't think we need to bother with this.
1292  */
1293 HINSTANCE16 WINAPI GetTaskDS16(void)
1294 {
1295     TDB *pTask;
1296
1297     if (!(pTask = TASK_GetCurrent())) return 0;
1298     return GlobalHandleToSel16(pTask->hInstance);
1299 }
1300
1301 /***********************************************************************
1302  *           GetDummyModuleHandleDS   (KERNEL.602)
1303  */
1304 WORD WINAPI GetDummyModuleHandleDS16(void)
1305 {
1306     TDB *pTask;
1307     WORD selector;
1308
1309     if (!(pTask = TASK_GetCurrent())) return 0;
1310     if (!(pTask->flags & TDBF_WIN32)) return 0;
1311     selector = GlobalHandleToSel16( pTask->hModule );
1312     CURRENT_DS = selector;
1313     return selector;
1314 }
1315
1316 /***********************************************************************
1317  *           IsTask   (KERNEL.320)
1318  */
1319 BOOL16 WINAPI IsTask16( HTASK16 hTask )
1320 {
1321     TDB *pTask;
1322
1323     if (!(pTask = TASK_GetPtr( hTask ))) return FALSE;
1324     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1325     return (pTask->magic == TDB_MAGIC);
1326 }
1327
1328
1329 /***********************************************************************
1330  *           IsWinOldApTask   (KERNEL.158)
1331  */
1332 BOOL16 WINAPI IsWinOldApTask16( HTASK16 hTask )
1333 {
1334     /* should return bit 0 of byte 0x48 in PSP */
1335     return FALSE;
1336 }
1337
1338 /***********************************************************************
1339  *           SetTaskSignalProc   (KERNEL.38)
1340  */
1341 FARPROC16 WINAPI SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1342 {
1343     TDB *pTask;
1344     FARPROC16 oldProc;
1345
1346     if (!hTask) hTask = GetCurrentTask();
1347     if (!(pTask = TASK_GetPtr( hTask ))) return NULL;
1348     oldProc = pTask->userhandler;
1349     pTask->userhandler = proc;
1350     return oldProc;
1351 }
1352
1353 /***********************************************************************
1354  *           SetSigHandler   (KERNEL.140)
1355  */
1356 WORD WINAPI SetSigHandler16( FARPROC16 newhandler, FARPROC16* oldhandler,
1357                            UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1358 {
1359     FIXME("(%p,%p,%p,%d,%d), unimplemented.\n",
1360           newhandler,oldhandler,oldmode,newmode,flag );
1361
1362     if (flag != 1) return 0;
1363     if (!newmode) newhandler = NULL;  /* Default handler */
1364     if (newmode != 4)
1365     {
1366         TDB *pTask;
1367
1368         if (!(pTask = TASK_GetCurrent())) return 0;
1369         if (oldmode) *oldmode = pTask->signal_flags;
1370         pTask->signal_flags = newmode;
1371         if (oldhandler) *oldhandler = pTask->sighandler;
1372         pTask->sighandler = newhandler;
1373     }
1374     return 0;
1375 }
1376
1377
1378 /***********************************************************************
1379  *           GlobalNotify   (KERNEL.154)
1380  *
1381  * Note that GlobalNotify does _not_ return the old NotifyProc
1382  * -- contrary to LocalNotify !!
1383  */
1384 VOID WINAPI GlobalNotify16( FARPROC16 proc )
1385 {
1386     TDB *pTask;
1387
1388     if (!(pTask = TASK_GetCurrent())) return;
1389     pTask->discardhandler = proc;
1390 }
1391
1392
1393 /***********************************************************************
1394  *           GetExePtrHelper
1395  */
1396 static inline HMODULE16 GetExePtrHelper( HANDLE16 handle, HTASK16 *hTask )
1397 {
1398     char *ptr;
1399     HANDLE16 owner;
1400
1401       /* Check for module handle */
1402
1403     if (!(ptr = GlobalLock16( handle ))) return 0;
1404     if (((NE_MODULE *)ptr)->ne_magic == IMAGE_OS2_SIGNATURE) return handle;
1405
1406       /* Search for this handle inside all tasks */
1407
1408     *hTask = hFirstTask;
1409     while (*hTask)
1410     {
1411         TDB *pTask = TASK_GetPtr( *hTask );
1412         if ((*hTask == handle) ||
1413             (pTask->hInstance == handle) ||
1414             (pTask->hQueue == handle) ||
1415             (pTask->hPDB == handle)) return pTask->hModule;
1416         *hTask = pTask->hNext;
1417     }
1418
1419       /* Check the owner for module handle */
1420
1421     owner = FarGetOwner16( handle );
1422     if (!(ptr = GlobalLock16( owner ))) return 0;
1423     if (((NE_MODULE *)ptr)->ne_magic == IMAGE_OS2_SIGNATURE) return owner;
1424
1425       /* Search for the owner inside all tasks */
1426
1427     *hTask = hFirstTask;
1428     while (*hTask)
1429     {
1430         TDB *pTask = TASK_GetPtr( *hTask );
1431         if ((*hTask == owner) ||
1432             (pTask->hInstance == owner) ||
1433             (pTask->hQueue == owner) ||
1434             (pTask->hPDB == owner)) return pTask->hModule;
1435         *hTask = pTask->hNext;
1436     }
1437
1438     return 0;
1439 }
1440
1441 /***********************************************************************
1442  *           GetExePtr   (KERNEL.133)
1443  */
1444 HMODULE16 WINAPI WIN16_GetExePtr( HANDLE16 handle )
1445 {
1446     HTASK16 hTask = 0;
1447     HMODULE16 hModule = GetExePtrHelper( handle, &hTask );
1448     STACK16FRAME *frame = CURRENT_STACK16;
1449     frame->ecx = hModule;
1450     if (hTask) frame->es = hTask;
1451     return hModule;
1452 }
1453
1454
1455 /***********************************************************************
1456  *           K228   (KERNEL.228)
1457  */
1458 HMODULE16 WINAPI GetExePtr( HANDLE16 handle )
1459 {
1460     HTASK16 hTask = 0;
1461     return GetExePtrHelper( handle, &hTask );
1462 }
1463
1464
1465 /***********************************************************************
1466  *           TaskFirst   (TOOLHELP.63)
1467  */
1468 BOOL16 WINAPI TaskFirst16( TASKENTRY *lpte )
1469 {
1470     lpte->hNext = hFirstTask;
1471     return TaskNext16( lpte );
1472 }
1473
1474
1475 /***********************************************************************
1476  *           TaskNext   (TOOLHELP.64)
1477  */
1478 BOOL16 WINAPI TaskNext16( TASKENTRY *lpte )
1479 {
1480     TDB *pTask;
1481     INSTANCEDATA *pInstData;
1482
1483     TRACE_(toolhelp)("(%p): task=%04x\n", lpte, lpte->hNext );
1484     if (!lpte->hNext) return FALSE;
1485
1486     /* make sure that task and hInstance are valid (skip initial Wine task !) */
1487     while (1) {
1488         pTask = TASK_GetPtr( lpte->hNext );
1489         if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1490         if (pTask->hInstance)
1491             break;
1492         lpte->hNext = pTask->hNext;
1493     }
1494     pInstData = MapSL( MAKESEGPTR( GlobalHandleToSel16(pTask->hInstance), 0 ) );
1495     lpte->hTask         = lpte->hNext;
1496     lpte->hTaskParent   = pTask->hParent;
1497     lpte->hInst         = pTask->hInstance;
1498     lpte->hModule       = pTask->hModule;
1499     lpte->wSS           = SELECTOROF( pTask->teb->WOW32Reserved );
1500     lpte->wSP           = OFFSETOF( pTask->teb->WOW32Reserved );
1501     lpte->wStackTop     = pInstData->stacktop;
1502     lpte->wStackMinimum = pInstData->stackmin;
1503     lpte->wStackBottom  = pInstData->stackbottom;
1504     lpte->wcEvents      = pTask->nEvents;
1505     lpte->hQueue        = pTask->hQueue;
1506     lstrcpynA( lpte->szModule, pTask->module_name, sizeof(lpte->szModule) );
1507     lpte->wPSPOffset    = 0x100;  /*??*/
1508     lpte->hNext         = pTask->hNext;
1509     return TRUE;
1510 }
1511
1512
1513 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND hWnd, LPCSTR text, LPCSTR title, UINT type);
1514
1515 /**************************************************************************
1516  *           FatalAppExit   (KERNEL.137)
1517  */
1518 void WINAPI FatalAppExit16( UINT16 action, LPCSTR str )
1519 {
1520     TDB *pTask = TASK_GetCurrent();
1521
1522     if (!pTask || !(pTask->error_mode & SEM_NOGPFAULTERRORBOX))
1523     {
1524         HMODULE mod = GetModuleHandleA( "user32.dll" );
1525         if (mod)
1526         {
1527             MessageBoxA_funcptr pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
1528             if (pMessageBoxA)
1529             {
1530                 pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
1531                 goto done;
1532             }
1533         }
1534         ERR( "%s\n", debugstr_a(str) );
1535     }
1536  done:
1537     ExitThread(0xff);
1538 }
1539
1540
1541 /***********************************************************************
1542  *           TerminateApp   (TOOLHELP.77)
1543  *
1544  * See "Undocumented Windows".
1545  */
1546 void WINAPI TerminateApp16(HTASK16 hTask, WORD wFlags)
1547 {
1548     if (hTask && hTask != GetCurrentTask())
1549     {
1550         FIXME("cannot terminate task %x\n", hTask);
1551         return;
1552     }
1553
1554     if (wFlags & NO_UAE_BOX)
1555     {
1556         UINT16 old_mode;
1557         old_mode = SetErrorMode16(0);
1558         SetErrorMode16(old_mode|SEM_NOGPFAULTERRORBOX);
1559     }
1560     FatalAppExit16( 0, NULL );
1561
1562     /* hmm, we're still alive ?? */
1563
1564     /* check undocumented flag */
1565     if (!(wFlags & 0x8000))
1566         TASK_CallTaskSignalProc( USIG16_TERMINATION, hTask );
1567
1568     /* UndocWin says to call int 0x21/0x4c exit=0xff here,
1569        but let's just call ExitThread */
1570     ExitThread(0xff);
1571 }
1572
1573
1574 /***********************************************************************
1575  *           GetAppCompatFlags   (KERNEL.354)
1576  */
1577 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1578 {
1579     TDB *pTask;
1580
1581     if (!hTask) hTask = GetCurrentTask();
1582     if (!(pTask=TASK_GetPtr( hTask ))) return 0;
1583     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1584     return pTask->compat_flags;
1585 }
1586
1587
1588 /***********************************************************************
1589  *           GetDOSEnvironment     (KERNEL.131)
1590  *
1591  * Note: the environment is allocated once, it doesn't track changes
1592  * made using the Win32 API. This shouldn't matter.
1593  *
1594  * Format of a 16-bit environment block:
1595  * ASCIIZ   string 1 (xx=yy format)
1596  * ...
1597  * ASCIIZ   string n
1598  * BYTE     0
1599  * WORD     1
1600  * ASCIIZ   program name (e.g. C:\WINDOWS\SYSTEM\KRNL386.EXE)
1601  */
1602 SEGPTR WINAPI GetDOSEnvironment16(void)
1603 {
1604     static const char ENV_program_name[] = "C:\\WINDOWS\\SYSTEM\\KRNL386.EXE";
1605     static HGLOBAL16 handle;  /* handle to the 16 bit environment */
1606
1607     if (!handle)
1608     {
1609         DWORD size;
1610         LPSTR p, env;
1611
1612         p = env = GetEnvironmentStringsA();
1613         while (*p) p += strlen(p) + 1;
1614         p++;  /* skip last null */
1615         size = (p - env) + sizeof(WORD) + sizeof(ENV_program_name);
1616         handle = GlobalAlloc16( GMEM_FIXED, size );
1617         if (handle)
1618         {
1619             WORD one = 1;
1620             LPSTR env16 = GlobalLock16( handle );
1621             memcpy( env16, env, p - env );
1622             memcpy( env16 + (p - env), &one, sizeof(one));
1623             memcpy( env16 + (p - env) + sizeof(WORD), ENV_program_name, sizeof(ENV_program_name));
1624             GlobalUnlock16( handle );
1625         }
1626         FreeEnvironmentStringsA( env );
1627     }
1628     return WOWGlobalLock16( handle );
1629 }