loader/task.c

   1 /*
   2  * Task functions
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  */
   6
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <assert.h>
  10 #include <unistd.h>
  11
  12 #include "wine/winbase16.h"
  13 #include "user.h"
  14 #include "callback.h"
  15 #include "drive.h"
  16 #include "file.h"
  17 #include "global.h"
  18 #include "instance.h"
  19 #include "message.h"
  20 #include "miscemu.h"
  21 #include "module.h"
  22 #include "neexe.h"
  23 #include "peexe.h"
  24 #include "pe_image.h"
  25 #include "process.h"
  26 #include "queue.h"
  27 #include "selectors.h"
  28 #include "stackframe.h"
  29 #include "task.h"
  30 #include "thread.h"
  31 #include "toolhelp.h"
  32 #include "winnt.h"
  33 #include "winsock.h"
  34 #include "thread.h"
  35 #include "syslevel.h"
  36 #include "debugtools.h"
  37 #include "dosexe.h"
  38 #include "dde_proc.h"
  39 #include "services.h"
  40 #include "server.h"
  41
  42 DECLARE_DEBUG_CHANNEL(relay)
  43 DECLARE_DEBUG_CHANNEL(task)
  44 DECLARE_DEBUG_CHANNEL(toolhelp)
  45
  46   /* Min. number of thunks allocated when creating a new segment */
  47 #define MIN_THUNKS  32
  48
  49   /* Pointer to function to switch to a larger stack */
  50 int (*IF1632_CallLargeStack)( int (*func)(), void *arg ) = NULL;
  51
  52   /* Pointer to debugger callback routine */
  53 void (*TASK_AddTaskEntryBreakpoint)( HTASK16 hTask ) = NULL;
  54
  55 static THHOOK DefaultThhook = { 0 };
  56 THHOOK *pThhook = &DefaultThhook;
  57
  58 #define hCurrentTask (pThhook->CurTDB)
  59 #define hFirstTask   (pThhook->HeadTDB)
  60 #define hLockedTask  (pThhook->LockTDB)
  61
  62 static UINT16 nTaskCount = 0;
  63
  64
  65 /***********************************************************************
  66  *           TASK_InstallTHHook
  67  */
  68 void TASK_InstallTHHook( THHOOK *pNewThhook )
  69 {
  70      THHOOK *pOldThhook = pThhook;
  71
  72      pThhook = pNewThhook? pNewThhook : &DefaultThhook;
  73
  74      *pThhook = *pOldThhook;
  75 }
  76
  77 /***********************************************************************
  78  *           TASK_GetNextTask
  79  */
  80 HTASK16 TASK_GetNextTask( HTASK16 hTask )
  81 {
  82     TDB* pTask = (TDB*)GlobalLock16(hTask);
  83
  84     if (pTask->hNext) return pTask->hNext;
  85     return (hFirstTask != hTask) ? hFirstTask : 0;
  86 }
  87
  88 /***********************************************************************
  89  *           TASK_LinkTask
  90  */
  91 static void TASK_LinkTask( HTASK16 hTask )
  92 {
  93     HTASK16 *prevTask;
  94     TDB *pTask;
  95
  96     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
  97     prevTask = &hFirstTask;
  98     while (*prevTask)
  99     {
 100         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
 101         if (prevTaskPtr->priority >= pTask->priority) break;
 102         prevTask = &prevTaskPtr->hNext;
 103     }
 104     pTask->hNext = *prevTask;
 105     *prevTask = hTask;
 106     nTaskCount++;
 107 }
 108
 109
 110 /***********************************************************************
 111  *           TASK_UnlinkTask
 112  */
 113 static void TASK_UnlinkTask( HTASK16 hTask )
 114 {
 115     HTASK16 *prevTask;
 116     TDB *pTask;
 117
 118     prevTask = &hFirstTask;
 119     while (*prevTask && (*prevTask != hTask))
 120     {
 121         pTask = (TDB *)GlobalLock16( *prevTask );
 122         prevTask = &pTask->hNext;
 123     }
 124     if (*prevTask)
 125     {
 126         pTask = (TDB *)GlobalLock16( *prevTask );
 127         *prevTask = pTask->hNext;
 128         pTask->hNext = 0;
 129         nTaskCount--;
 130     }
 131 }
 132
 133
 134 /***********************************************************************
 135  *           TASK_CreateThunks
 136  *
 137  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 138  * and containing 'count' entries.
 139  */
 140 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 141 {
 142     int i;
 143     WORD free;
 144     THUNKS *pThunk;
 145
 146     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 147     pThunk->next = 0;
 148     pThunk->magic = THUNK_MAGIC;
 149     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 150     free = pThunk->free;
 151     for (i = 0; i < count-1; i++)
 152     {
 153         free += 8;  /* Offset of next thunk */
 154         pThunk->thunks[4*i] = free;
 155     }
 156     pThunk->thunks[4*i] = 0;  /* Last thunk */
 157 }
 158
 159
 160 /***********************************************************************
 161  *           TASK_AllocThunk
 162  *
 163  * Allocate a thunk for MakeProcInstance().
 164  */
 165 static SEGPTR TASK_AllocThunk( HTASK16 hTask )
 166 {
 167     TDB *pTask;
 168     THUNKS *pThunk;
 169     WORD sel, base;
 170
 171     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 172     sel = pTask->hCSAlias;
 173     pThunk = &pTask->thunks;
 174     base = (int)pThunk - (int)pTask;
 175     while (!pThunk->free)
 176     {
 177         sel = pThunk->next;
 178         if (!sel)  /* Allocate a new segment */
 179         {
 180             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 181                                 pTask->hPDB, TRUE, FALSE, FALSE );
 182             if (!sel) return (SEGPTR)0;
 183             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 184             pThunk->next = sel;
 185         }
 186         pThunk = (THUNKS *)GlobalLock16( sel );
 187         base = 0;
 188     }
 189     base += pThunk->free;
 190     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 191     return PTR_SEG_OFF_TO_SEGPTR( sel, base );
 192 }
 193
 194
 195 /***********************************************************************
 196  *           TASK_FreeThunk
 197  *
 198  * Free a MakeProcInstance() thunk.
 199  */
 200 static BOOL TASK_FreeThunk( HTASK16 hTask, SEGPTR thunk )
 201 {
 202     TDB *pTask;
 203     THUNKS *pThunk;
 204     WORD sel, base;
 205
 206     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 207     sel = pTask->hCSAlias;
 208     pThunk = &pTask->thunks;
 209     base = (int)pThunk - (int)pTask;
 210     while (sel && (sel != HIWORD(thunk)))
 211     {
 212         sel = pThunk->next;
 213         pThunk = (THUNKS *)GlobalLock16( sel );
 214         base = 0;
 215     }
 216     if (!sel) return FALSE;
 217     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 218     pThunk->free = LOWORD(thunk) - base;
 219     return TRUE;
 220 }
 221
 222
 223 /***********************************************************************
 224  *           TASK_CallToStart
 225  *
 226  * 32-bit entry point for a new task. This function is responsible for
 227  * setting up the registers and jumping to the 16-bit entry point.
 228  */
 229 void TASK_CallToStart(void)
 230 {
 231     TDB *pTask = (TDB *)GlobalLock16( GetCurrentTask() );
 232     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 233     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 234     CONTEXT context;
 235
 236     /* Add task to 16-bit scheduler pool */
 237     TASK_Reschedule();
 238
 239     /* Registers at initialization must be:
 240      * ax   zero
 241      * bx   stack size in bytes
 242      * cx   heap size in bytes
 243      * si   previous app instance
 244      * di   current app instance
 245      * bp   zero
 246      * es   selector to the PSP
 247      * ds   dgroup of the application
 248      * ss   stack selector
 249      * sp   top of the stack
 250      */
 251
 252     memset( &context, 0, sizeof(context) );
 253     CS_reg(&context)  = GlobalHandleToSel16(pSegTable[pModule->cs - 1].hSeg);
 254     DS_reg(&context)  = GlobalHandleToSel16(pSegTable[pModule->dgroup - 1].hSeg);
 255     ES_reg(&context)  = pTask->hPDB;
 256     EIP_reg(&context) = pModule->ip;
 257     EBX_reg(&context) = pModule->stack_size;
 258     ECX_reg(&context) = pModule->heap_size;
 259     EDI_reg(&context) = context.SegDs;
 260
 261     TRACE_(task)("Starting main program: cs:ip=%04lx:%04x ds=%04lx ss:sp=%04x:%04x\n",
 262                   CS_reg(&context), IP_reg(&context), DS_reg(&context),
 263                   SELECTOROF(pTask->teb->cur_stack),
 264                   OFFSETOF(pTask->teb->cur_stack) );
 265
 266     Callbacks->CallRegisterShortProc( &context, 0 );
 267 }
 268
 269
 270 /***********************************************************************
 271  *           TASK_Create
 272  *
 273  * NOTE: This routine might be called by a Win32 thread. Thus, we need
 274  *       to be careful to protect global data structures. We do this
 275  *       by entering the Win16Lock while linking the task into the
 276  *       global task list.
 277  */
 278 BOOL TASK_Create( NE_MODULE *pModule, HINSTANCE16 hInstance,
 279                   HINSTANCE16 hPrevInstance, UINT16 cmdShow)
 280 {
 281     HTASK16 hTask;
 282     TDB *pTask;
 283     LPSTR cmd_line;
 284     WORD sp;
 285     char name[10];
 286     PDB *pdb32 = PROCESS_Current();
 287     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 288
 289       /* Allocate the task structure */
 290
 291     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 292                           pModule->self, FALSE, FALSE, FALSE );
 293     if (!hTask) return FALSE;
 294     pTask = (TDB *)GlobalLock16( hTask );
 295
 296     /* Fill the task structure */
 297
 298     pTask->nEvents       = 0;
 299     pTask->hSelf         = hTask;
 300     pTask->flags         = 0;
 301
 302     if (pModule->flags & NE_FFLAGS_WIN32)
 303         pTask->flags    |= TDBF_WIN32;
 304     if (pModule->lpDosTask)
 305         pTask->flags    |= TDBF_WINOLDAP;
 306
 307     pTask->version       = pModule->expected_version;
 308     pTask->hInstance     = hInstance? hInstance : pModule->self;
 309     pTask->hPrevInstance = hPrevInstance;
 310     pTask->hModule       = pModule->self;
 311     pTask->hParent       = GetCurrentTask();
 312     pTask->magic         = TDB_MAGIC;
 313     pTask->nCmdShow      = cmdShow;
 314     pTask->teb           = NtCurrentTeb();
 315     pTask->curdrive      = DRIVE_GetCurrentDrive() | 0x80;
 316     strcpy( pTask->curdir, "\\" );
 317     lstrcpynA( pTask->curdir + 1, DRIVE_GetDosCwd( DRIVE_GetCurrentDrive() ),
 318                  sizeof(pTask->curdir) - 1 );
 319
 320       /* Create the thunks block */
 321
 322     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 323
 324       /* Copy the module name */
 325
 326     GetModuleName16( pModule->self, name, sizeof(name) );
 327     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 328
 329       /* Allocate a selector for the PDB */
 330
 331     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB16),
 332                                     pModule->self, FALSE, FALSE, FALSE, NULL );
 333
 334       /* Fill the PDB */
 335
 336     pTask->pdb.int20 = 0x20cd;
 337     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 338     PUT_DWORD(&pTask->pdb.dispatcher[1], (DWORD)NE_GetEntryPoint(
 339            GetModuleHandle16("KERNEL"), 102 ));  /* KERNEL.102 is DOS3Call() */
 340     pTask->pdb.savedint22 = INT_GetPMHandler( 0x22 );
 341     pTask->pdb.savedint23 = INT_GetPMHandler( 0x23 );
 342     pTask->pdb.savedint24 = INT_GetPMHandler( 0x24 );
 343     pTask->pdb.fileHandlesPtr =
 344         PTR_SEG_OFF_TO_SEGPTR( GlobalHandleToSel16(pTask->hPDB),
 345                                (int)&((PDB16 *)0)->fileHandles );
 346     pTask->pdb.hFileHandles = 0;
 347     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 348     pTask->pdb.environment    = pdb32->env_db->env_sel;
 349     pTask->pdb.nbFiles        = 20;
 350
 351     /* Fill the command line */
 352
 353     cmd_line = pdb32->env_db->cmd_line;
 354     while (*cmd_line && (*cmd_line != ' ') && (*cmd_line != '\t')) cmd_line++;
 355     while ((*cmd_line == ' ') || (*cmd_line == '\t')) cmd_line++;
 356     lstrcpynA( pTask->pdb.cmdLine+1, cmd_line, sizeof(pTask->pdb.cmdLine)-1);
 357     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 358
 359       /* Get the compatibility flags */
 360
 361     pTask->compat_flags = GetProfileIntA( "Compatibility", name, 0 );
 362
 363       /* Allocate a code segment alias for the TDB */
 364
 365     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 366                                           sizeof(TDB), pTask->hPDB, TRUE,
 367                                           FALSE, FALSE, NULL );
 368
 369       /* Set the owner of the environment block */
 370
 371     FarSetOwner16( pTask->pdb.environment, pTask->hPDB );
 372
 373       /* Default DTA overwrites command-line */
 374
 375     pTask->dta = PTR_SEG_OFF_TO_SEGPTR( pTask->hPDB,
 376                                 (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 377
 378     /* Create scheduler event for 16-bit tasks */
 379
 380     if ( !(pTask->flags & TDBF_WIN32) )
 381     {
 382         pTask->hEvent = CreateEventA( NULL, TRUE, FALSE, NULL );
 383         pTask->hEvent = ConvertToGlobalHandle( pTask->hEvent );
 384     }
 385
 386     /* Enter task handle into thread and process */
 387
 388     pTask->teb->htask16 = pTask->teb->process->task = hTask;
 389     TRACE_(task)("module='%s' cmdline='%s' task=%04x\n", name, cmd_line, hTask );
 390
 391     /* If we have a DGROUP/hInstance, use it for 16-bit stack */
 392
 393     if ( hInstance )
 394     {
 395         if (!(sp = pModule->sp))
 396             sp = pSegTable[pModule->ss-1].minsize + pModule->stack_size;
 397         sp &= ~1;  sp -= sizeof(STACK16FRAME);
 398         pTask->teb->cur_stack = PTR_SEG_OFF_TO_SEGPTR( hInstance, sp );
 399     }
 400
 401     /* If requested, add entry point breakpoint */
 402
 403     if ( TASK_AddTaskEntryBreakpoint )
 404         TASK_AddTaskEntryBreakpoint( hTask );
 405
 406     /* Add the task to the linked list */
 407
 408     SYSLEVEL_EnterWin16Lock();
 409     TASK_LinkTask( hTask );
 410     SYSLEVEL_LeaveWin16Lock();
 411
 412     return TRUE;
 413 }
 414
 415 /***********************************************************************
 416  *           TASK_DeleteTask
 417  */
 418 static void TASK_DeleteTask( HTASK16 hTask )
 419 {
 420     TDB *pTask;
 421     HGLOBAL16 hPDB;
 422
 423     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 424     hPDB = pTask->hPDB;
 425
 426     pTask->magic = 0xdead; /* invalidate signature */
 427
 428     /* Delete the Win32 part of the task */
 429
 430 /*    PROCESS_FreePDB( pTask->teb->process ); FIXME */
 431 /*    K32OBJ_DecCount( &pTask->teb->header ); FIXME */
 432
 433     /* Free the selector aliases */
 434
 435     GLOBAL_FreeBlock( pTask->hCSAlias );
 436     GLOBAL_FreeBlock( pTask->hPDB );
 437
 438     /* Free the task module */
 439
 440     FreeModule16( pTask->hModule );
 441
 442     /* Free the task structure itself */
 443
 444     GlobalFree16( hTask );
 445
 446     /* Free all memory used by this task (including the 32-bit stack, */
 447     /* the environment block and the thunk segments). */
 448
 449     GlobalFreeAll16( hPDB );
 450 }
 451
 452 /***********************************************************************
 453  *           TASK_KillTask
 454  */
 455 void TASK_KillTask( HTASK16 hTask )
 456 {
 457     TDB *pTask;
 458
 459     /* Enter the Win16Lock to protect global data structures */
 460     SYSLEVEL_EnterWin16Lock();
 461
 462     if ( !hTask ) hTask = GetCurrentTask();
 463     pTask = (TDB *)GlobalLock16( hTask );
 464     if ( !pTask )
 465     {
 466         SYSLEVEL_LeaveWin16Lock();
 467         return;
 468     }
 469
 470     TRACE_(task)("Killing task %04x\n", hTask );
 471
 472     /* Delete active sockets */
 473
 474     if( pTask->pwsi )
 475         WINSOCK_DeleteTaskWSI( pTask, pTask->pwsi );
 476
 477 #ifdef MZ_SUPPORTED
 478 {
 479     /* Kill DOS VM task */
 480     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 481     if ( pModule->lpDosTask )
 482         MZ_KillModule( pModule->lpDosTask );
 483 }
 484 #endif
 485
 486     /* Perform USER cleanup */
 487
 488     if (pTask->userhandler)
 489         pTask->userhandler( hTask, USIG16_TERMINATION, 0,
 490                             pTask->hInstance, pTask->hQueue );
 491
 492     PROCESS_CallUserSignalProc( USIG_PROCESS_EXIT, 0 );
 493     PROCESS_CallUserSignalProc( USIG_THREAD_EXIT, 0 );     /* FIXME */
 494     PROCESS_CallUserSignalProc( USIG_PROCESS_DESTROY, 0 );
 495
 496     if (nTaskCount <= 1)
 497     {
 498         TRACE_(task)("this is the last task, exiting\n" );
 499         ExitKernel16();
 500     }
 501
 502     /* FIXME: Hack! Send a message to the initial task so that
 503      * the GetMessage wakes up and the initial task can check whether
 504      * it is the only remaining one and terminate itself ...
 505      * The initial task should probably install hooks or something
 506      * to get informed about task termination :-/
 507      */
 508     Callout.PostAppMessage16( PROCESS_Initial()->task, WM_NULL, 0, 0 );
 509
 510     /* Remove the task from the list to be sure we never switch back to it */
 511     TASK_UnlinkTask( hTask );
 512     if( nTaskCount )
 513     {
 514         TDB* p = (TDB *)GlobalLock16( hFirstTask );
 515         while( p )
 516         {
 517             if( p->hYieldTo == hTask ) p->hYieldTo = 0;
 518             p = (TDB *)GlobalLock16( p->hNext );
 519         }
 520     }
 521
 522     pTask->nEvents = 0;
 523
 524     if ( hLockedTask == hTask )
 525         hLockedTask = 0;
 526
 527     TASK_DeleteTask( hTask );
 528
 529     /* When deleting the current task ... */
 530     if ( hTask == hCurrentTask )
 531     {
 532         DWORD lockCount;
 533
 534         /* ... schedule another one ... */
 535         TASK_Reschedule();
 536
 537         /* ... and completely release the Win16Lock, just in case. */
 538         ReleaseThunkLock( &lockCount );
 539
 540         return;
 541     }
 542
 543     SYSLEVEL_LeaveWin16Lock();
 544 }
 545
 546 /***********************************************************************
 547  *           TASK_Reschedule
 548  *
 549  * This is where all the magic of task-switching happens!
 550  *
 551  * 16-bit Windows performs non-preemptive (cooperative) multitasking.
 552  * This means that each 16-bit task runs until it voluntarily yields
 553  * control, at which point the scheduler gets active and selects the
 554  * next task to run.
 555  *
 556  * In Wine, all processes, even 16-bit ones, are scheduled preemptively
 557  * by the standard scheduler of the underlying OS.  As many 16-bit apps
 558  * *rely* on the behaviour of the Windows scheduler, however, we have
 559  * to simulate that behaviour.
 560  *
 561  * This is achieved as follows: every 16-bit task is at time (except
 562  * during task creation and deletion) in one of two states: either it
 563  * is the one currently running, then the global variable hCurrentTask
 564  * contains its task handle, or it is not currently running, then it
 565  * is blocked on a special scheduler event, a global handle to which
 566  * is stored in the task struct.
 567  *
 568  * When the current task yields control, this routine gets called. Its
 569  * purpose is to determine the next task to be active, signal the
 570  * scheduler event of that task, and then put the current task to sleep
 571  * waiting for *its* scheduler event to get signalled again.
 572  *
 573  * This routine can get called in a few other special situations as well:
 574  *
 575  * - On creation of a 16-bit task, the Unix process executing the task
 576  *   calls TASK_Reschedule once it has completed its initialization.
 577  *   At this point, the task needs to be blocked until its scheduler
 578  *   event is signalled the first time (this will be done by the parent
 579  *   process to get the task up and running).
 580  *
 581  * - When the task currently running terminates itself, this routine gets
 582  *   called and has to schedule another task, *without* blocking the
 583  *   terminating task.
 584  *
 585  * - When a 32-bit thread posts an event for a 16-bit task, it might be
 586  *   the case that *no* 16-bit task is currently running.  In this case
 587  *   the task that has now an event pending is to be scheduled.
 588  *
 589  */
 590 void TASK_Reschedule(void)
 591 {
 592     TDB *pOldTask = NULL, *pNewTask = NULL;
 593     HTASK16 hOldTask = 0, hNewTask = 0;
 594     enum { MODE_YIELD, MODE_SLEEP, MODE_WAKEUP } mode;
 595     DWORD lockCount;
 596
 597     SYSLEVEL_EnterWin16Lock();
 598
 599     /* Check what we need to do */
 600     hOldTask = GetCurrentTask();
 601     pOldTask = (TDB *)GlobalLock16( hOldTask );
 602     TRACE_(task)( "entered with hCurrentTask %04x by hTask %04x (pid %d)\n",
 603                   hCurrentTask, hOldTask, getpid() );
 604
 605     if ( pOldTask && THREAD_IsWin16( NtCurrentTeb() ) )
 606     {
 607         /* We are called by an active (non-deleted) 16-bit task */
 608
 609         /* If we don't even have a current task, or else the current
 610            task has yielded, we'll need to schedule a new task and
 611            (possibly) put the calling task to sleep.  Otherwise, we
 612            only block the caller. */
 613
 614         if ( !hCurrentTask || hCurrentTask == hOldTask )
 615             mode = MODE_YIELD;
 616         else
 617             mode = MODE_SLEEP;
 618     }
 619     else
 620     {
 621         /* We are called by a deleted 16-bit task or a 32-bit thread */
 622
 623         /* The only situation where we need to do something is if we
 624            now do not have a current task.  Then, we'll need to wake up
 625            some task that has events pending. */
 626
 627         if ( !hCurrentTask || hCurrentTask == hOldTask )
 628             mode = MODE_WAKEUP;
 629         else
 630         {
 631             /* nothing to do */
 632             SYSLEVEL_LeaveWin16Lock();
 633             return;
 634         }
 635     }
 636
 637     /* Find a task to yield to: check for DirectedYield() */
 638     if ( mode == MODE_YIELD && pOldTask && pOldTask->hYieldTo )
 639     {
 640         hNewTask = pOldTask->hYieldTo;
 641         pNewTask = (TDB *)GlobalLock16( hNewTask );
 642         if( !pNewTask || !pNewTask->nEvents) hNewTask = 0;
 643         pOldTask->hYieldTo = 0;
 644     }
 645
 646     /* Find a task to yield to: check for pending events */
 647     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && !hNewTask )
 648     {
 649         hNewTask = hFirstTask;
 650         while (hNewTask)
 651         {
 652             pNewTask = (TDB *)GlobalLock16( hNewTask );
 653
 654             TRACE_(task)( "\ttask = %04x, events = %i\n",
 655                           hNewTask, pNewTask->nEvents );
 656
 657             if (pNewTask->nEvents) break;
 658             hNewTask = pNewTask->hNext;
 659         }
 660         if (hLockedTask && (hNewTask != hLockedTask)) hNewTask = 0;
 661     }
 662
 663     /* If we are still the task with highest priority, just return ... */
 664     if ( mode == MODE_YIELD && hNewTask == hCurrentTask )
 665     {
 666         TRACE_(task)("returning to the current task (%04x)\n", hCurrentTask );
 667         SYSLEVEL_LeaveWin16Lock();
 668
 669         /* Allow Win32 threads to thunk down even while a Win16 task is
 670            in a tight PeekMessage() or Yield() loop ... */
 671         ReleaseThunkLock( &lockCount );
 672         RestoreThunkLock( lockCount );
 673         return;
 674     }
 675
 676     /* If no task to yield to found, suspend 16-bit scheduler ... */
 677     if ( mode == MODE_YIELD && !hNewTask )
 678     {
 679         TRACE_(task)("No currently active task\n");
 680         hCurrentTask = 0;
 681     }
 682
 683     /* If we found a task to wake up, do it ... */
 684     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && hNewTask )
 685     {
 686         TRACE_(task)("Switching to task %04x (%.8s)\n",
 687                       hNewTask, pNewTask->module_name );
 688
 689         pNewTask->priority++;
 690         TASK_UnlinkTask( hNewTask );
 691         TASK_LinkTask( hNewTask );
 692         pNewTask->priority--;
 693
 694         hCurrentTask = hNewTask;
 695         SetEvent( pNewTask->hEvent );
 696
 697         /* This is set just in case some app reads it ... */
 698         pNewTask->ss_sp = pNewTask->teb->cur_stack;
 699     }
 700
 701     /* If we need to put the current task to sleep, do it ... */
 702     if ( (mode == MODE_YIELD || mode == MODE_SLEEP) && hOldTask != hCurrentTask )
 703     {
 704         ResetEvent( pOldTask->hEvent );
 705
 706         ReleaseThunkLock( &lockCount );
 707         SYSLEVEL_CheckNotLevel( 1 );
 708         WaitForSingleObject( pOldTask->hEvent, INFINITE );
 709         RestoreThunkLock( lockCount );
 710     }
 711
 712     SYSLEVEL_LeaveWin16Lock();
 713 }
 714
 715 /***********************************************************************
 716  *           InitTask  (KERNEL.91)
 717  *
 718  * Called by the application startup code.
 719  */
 720 void WINAPI InitTask16( CONTEXT *context )
 721 {
 722     TDB *pTask;
 723     NE_MODULE *pModule;
 724     SEGTABLEENTRY *pSegTable;
 725     INSTANCEDATA *pinstance;
 726     LONG stacklow, stackhi;
 727
 728     if (context) EAX_reg(context) = 0;
 729     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
 730     if (!(pModule = NE_GetPtr( pTask->hModule ))) return;
 731
 732     /* Initialize implicitly loaded DLLs */
 733     NE_InitializeDLLs( pTask->hModule );
 734
 735     if (context)
 736     {
 737         /* Registers on return are:
 738          * ax     1 if OK, 0 on error
 739          * cx     stack limit in bytes
 740          * dx     cmdShow parameter
 741          * si     instance handle of the previous instance
 742          * di     instance handle of the new task
 743          * es:bx  pointer to command-line inside PSP
 744          *
 745          * 0 (=%bp) is pushed on the stack
 746          */
 747         SEGPTR ptr = STACK16_PUSH( pTask->teb, sizeof(WORD) );
 748         *(WORD *)PTR_SEG_TO_LIN(ptr) = 0;
 749         SP_reg(context) -= 2;
 750
 751         EAX_reg(context) = 1;
 752
 753         if (!pTask->pdb.cmdLine[0]) EBX_reg(context) = 0x80;
 754         else
 755         {
 756             LPBYTE p = &pTask->pdb.cmdLine[1];
 757             while ((*p == ' ') || (*p == '\t')) p++;
 758             EBX_reg(context) = 0x80 + (p - pTask->pdb.cmdLine);
 759         }
 760         ECX_reg(context) = pModule->stack_size;
 761         EDX_reg(context) = pTask->nCmdShow;
 762         ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 763         EDI_reg(context) = (DWORD)pTask->hInstance;
 764         ES_reg (context) = (WORD)pTask->hPDB;
 765     }
 766
 767     /* Initialize the local heap */
 768     if ( pModule->heap_size )
 769     {
 770         LocalInit16( pTask->hInstance, 0, pModule->heap_size );
 771     }
 772
 773     /* Initialize the INSTANCEDATA structure */
 774     pSegTable = NE_SEG_TABLE( pModule );
 775     stacklow = pSegTable[pModule->ss - 1].minsize;
 776     stackhi  = stacklow + pModule->stack_size;
 777     if (stackhi > 0xffff) stackhi = 0xffff;
 778     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 779     pinstance->stackbottom = stackhi; /* yup, that's right. Confused me too. */
 780     pinstance->stacktop    = stacklow;
 781     pinstance->stackmin    = OFFSETOF( pTask->teb->cur_stack );
 782 }
 783
 784
 785 /***********************************************************************
 786  *           WaitEvent  (KERNEL.30)
 787  */
 788 BOOL16 WINAPI WaitEvent16( HTASK16 hTask )
 789 {
 790     TDB *pTask;
 791
 792     if (!hTask) hTask = GetCurrentTask();
 793     pTask = (TDB *)GlobalLock16( hTask );
 794
 795     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 796     {
 797         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 798         return TRUE;
 799     }
 800
 801     if (pTask->nEvents > 0)
 802     {
 803         pTask->nEvents--;
 804         return FALSE;
 805     }
 806     TASK_Reschedule();
 807
 808     /* When we get back here, we have an event */
 809
 810     if (pTask->nEvents > 0) pTask->nEvents--;
 811     return TRUE;
 812 }
 813
 814
 815 /***********************************************************************
 816  *           PostEvent  (KERNEL.31)
 817  */
 818 void WINAPI PostEvent16( HTASK16 hTask )
 819 {
 820     TDB *pTask;
 821
 822     if (!hTask) hTask = GetCurrentTask();
 823     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 824
 825     if ( !THREAD_IsWin16( pTask->teb ) )
 826     {
 827         FIXME_(task)("called for Win32 thread (%04x)!\n", pTask->teb->teb_sel );
 828         return;
 829     }
 830
 831     pTask->nEvents++;
 832
 833     /* If we are a 32-bit task, we might need to wake up the 16-bit scheduler */
 834     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 835         TASK_Reschedule();
 836 }
 837
 838
 839 /***********************************************************************
 840  *           SetPriority  (KERNEL.32)
 841  */
 842 void WINAPI SetPriority16( HTASK16 hTask, INT16 delta )
 843 {
 844     TDB *pTask;
 845     INT16 newpriority;
 846
 847     if (!hTask) hTask = GetCurrentTask();
 848     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 849     newpriority = pTask->priority + delta;
 850     if (newpriority < -32) newpriority = -32;
 851     else if (newpriority > 15) newpriority = 15;
 852
 853     pTask->priority = newpriority + 1;
 854     TASK_UnlinkTask( hTask );
 855     TASK_LinkTask( hTask );
 856     pTask->priority--;
 857 }
 858
 859
 860 /***********************************************************************
 861  *           LockCurrentTask  (KERNEL.33)
 862  */
 863 HTASK16 WINAPI LockCurrentTask16( BOOL16 bLock )
 864 {
 865     if (bLock) hLockedTask = GetCurrentTask();
 866     else hLockedTask = 0;
 867     return hLockedTask;
 868 }
 869
 870
 871 /***********************************************************************
 872  *           IsTaskLocked  (KERNEL.122)
 873  */
 874 HTASK16 WINAPI IsTaskLocked16(void)
 875 {
 876     return hLockedTask;
 877 }
 878
 879
 880 /***********************************************************************
 881  *           OldYield  (KERNEL.117)
 882  */
 883 void WINAPI OldYield16(void)
 884 {
 885     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 886
 887     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 888     {
 889         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 890         return;
 891     }
 892
 893     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 894     TASK_Reschedule();
 895     if (pCurTask) pCurTask->nEvents--;
 896 }
 897
 898
 899 /***********************************************************************
 900  *           DirectedYield  (KERNEL.150)
 901  */
 902 void WINAPI DirectedYield16( HTASK16 hTask )
 903 {
 904     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 905
 906     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 907     {
 908         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 909         return;
 910     }
 911
 912     TRACE_(task)("%04x: DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 913
 914     pCurTask->hYieldTo = hTask;
 915     OldYield16();
 916
 917     TRACE_(task)("%04x: back from DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 918 }
 919
 920 /***********************************************************************
 921  *           Yield16  (KERNEL.29)
 922  */
 923 void WINAPI Yield16(void)
 924 {
 925     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 926
 927     if (pCurTask) pCurTask->hYieldTo = 0;
 928     if (pCurTask && pCurTask->hQueue) Callout.UserYield16();
 929     else OldYield16();
 930 }
 931
 932 /***********************************************************************
 933  *           KERNEL_490  (KERNEL.490)
 934  */
 935 HTASK16 WINAPI KERNEL_490( HTASK16 someTask )
 936 {
 937     if ( !someTask ) return 0;
 938
 939     FIXME_(task)("(%04x): stub\n", someTask );
 940     return 0;
 941 }
 942
 943 /***********************************************************************
 944  *           MakeProcInstance16  (KERNEL.51)
 945  */
 946 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 947 {
 948     BYTE *thunk,*lfunc;
 949     SEGPTR thunkaddr;
 950
 951     if (!func) {
 952       ERR_(task)("Ouch ! MakeProcInstance called with func == NULL !\n");
 953       return (FARPROC16)0; /* Windows seems to do the same */
 954     }
 955     if (!hInstance) hInstance = CURRENT_DS;
 956     thunkaddr = TASK_AllocThunk( GetCurrentTask() );
 957     if (!thunkaddr) return (FARPROC16)0;
 958     thunk = PTR_SEG_TO_LIN( thunkaddr );
 959     lfunc = PTR_SEG_TO_LIN( func );
 960
 961     TRACE_(task)("(%08lx,%04x): got thunk %08lx\n",
 962                   (DWORD)func, hInstance, (DWORD)thunkaddr );
 963     if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) ||
 964         ((lfunc[0]==0x1e) && (lfunc[1]==0x58))
 965     ) {
 966         FIXME_(task)("thunk would be useless for %p, overwriting with nop;nop;\n", func );
 967         lfunc[0]=0x90; /* nop */
 968         lfunc[1]=0x90; /* nop */
 969     }
 970
 971     *thunk++ = 0xb8;    /* movw instance, %ax */
 972     *thunk++ = (BYTE)(hInstance & 0xff);
 973     *thunk++ = (BYTE)(hInstance >> 8);
 974     *thunk++ = 0xea;    /* ljmp func */
 975     *(DWORD *)thunk = (DWORD)func;
 976     return (FARPROC16)thunkaddr;
 977 }
 978
 979
 980 /***********************************************************************
 981  *           FreeProcInstance16  (KERNEL.52)
 982  */
 983 void WINAPI FreeProcInstance16( FARPROC16 func )
 984 {
 985     TRACE_(task)("(%08lx)\n", (DWORD)func );
 986     TASK_FreeThunk( GetCurrentTask(), (SEGPTR)func );
 987 }
 988
 989
 990 /**********************************************************************
 991  *          GetCodeHandle    (KERNEL.93)
 992  */
 993 HANDLE16 WINAPI GetCodeHandle16( FARPROC16 proc )
 994 {
 995     HANDLE16 handle;
 996     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
 997
 998     /* Return the code segment containing 'proc'. */
 999     /* Not sure if this is really correct (shouldn't matter that much). */
1000
1001     /* Check if it is really a thunk */
1002     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1003         handle = GlobalHandle16( thunk[6] + (thunk[7] << 8) );
1004     else
1005         handle = GlobalHandle16( HIWORD(proc) );
1006
1007     return handle;
1008 }
1009
1010 /**********************************************************************
1011  *          GetCodeInfo    (KERNEL.104)
1012  */
1013 VOID WINAPI GetCodeInfo16( FARPROC16 proc, SEGINFO *segInfo )
1014 {
1015     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
1016     NE_MODULE *pModule = NULL;
1017     SEGTABLEENTRY *pSeg = NULL;
1018     WORD segNr;
1019
1020     /* proc is either a thunk, or else a pair of module handle
1021        and segment number. In the first case, we also need to
1022        extract module and segment number. */
1023
1024     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1025     {
1026         WORD selector = thunk[6] + (thunk[7] << 8);
1027         pModule = NE_GetPtr( GlobalHandle16( selector ) );
1028         pSeg = pModule? NE_SEG_TABLE( pModule ) : NULL;
1029
1030         if ( pModule )
1031             for ( segNr = 0; segNr < pModule->seg_count; segNr++, pSeg++ )
1032                 if ( GlobalHandleToSel16(pSeg->hSeg) == selector )
1033                     break;
1034
1035         if ( pModule && segNr >= pModule->seg_count )
1036             pSeg = NULL;
1037     }
1038     else
1039     {
1040         pModule = NE_GetPtr( HIWORD( proc ) );
1041         segNr   = LOWORD( proc );
1042
1043         if ( pModule && segNr < pModule->seg_count )
1044             pSeg = NE_SEG_TABLE( pModule ) + segNr;
1045     }
1046
1047     /* fill in segment information */
1048
1049     segInfo->offSegment = pSeg? pSeg->filepos : 0;
1050     segInfo->cbSegment  = pSeg? pSeg->size : 0;
1051     segInfo->flags      = pSeg? pSeg->flags : 0;
1052     segInfo->cbAlloc    = pSeg? pSeg->minsize : 0;
1053     segInfo->h          = pSeg? pSeg->hSeg : 0;
1054     segInfo->alignShift = pModule? pModule->alignment : 0;
1055 }
1056
1057
1058 /**********************************************************************
1059  *          DefineHandleTable16    (KERNEL.94)
1060  */
1061 BOOL16 WINAPI DefineHandleTable16( WORD wOffset )
1062 {
1063     return TRUE;  /* FIXME */
1064 }
1065
1066
1067 /***********************************************************************
1068  *           SetTaskQueue  (KERNEL.34)
1069  */
1070 HQUEUE16 WINAPI SetTaskQueue16( HTASK16 hTask, HQUEUE16 hQueue )
1071 {
1072     HQUEUE16 hPrev;
1073     TDB *pTask;
1074
1075     if (!hTask) hTask = GetCurrentTask();
1076     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1077
1078     hPrev = pTask->hQueue;
1079     pTask->hQueue = hQueue;
1080
1081     return hPrev;
1082 }
1083
1084
1085 /***********************************************************************
1086  *           GetTaskQueue  (KERNEL.35)
1087  */
1088 HQUEUE16 WINAPI GetTaskQueue16( HTASK16 hTask )
1089 {
1090     TDB *pTask;
1091
1092     if (!hTask) hTask = GetCurrentTask();
1093     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1094     return pTask->hQueue;
1095 }
1096
1097 /***********************************************************************
1098  *           SetThreadQueue  (KERNEL.463)
1099  */
1100 HQUEUE16 WINAPI SetThreadQueue16( DWORD thread, HQUEUE16 hQueue )
1101 {
1102     TEB *teb = thread? THREAD_IdToTEB( thread ) : NtCurrentTeb();
1103     HQUEUE16 oldQueue = teb? teb->queue : 0;
1104
1105     if ( teb )
1106     {
1107         teb->queue = hQueue;
1108
1109         if ( GetTaskQueue16( teb->process->task ) == oldQueue )
1110             SetTaskQueue16( teb->process->task, hQueue );
1111     }
1112
1113     return oldQueue;
1114 }
1115
1116 /***********************************************************************
1117  *           GetThreadQueue  (KERNEL.464)
1118  */
1119 HQUEUE16 WINAPI GetThreadQueue16( DWORD thread )
1120 {
1121     TEB *teb = NULL;
1122     if ( !thread )
1123         teb = NtCurrentTeb();
1124     else if ( HIWORD(thread) )
1125         teb = THREAD_IdToTEB( thread );
1126     else if ( IsTask16( (HTASK16)thread ) )
1127         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1128
1129     return (HQUEUE16)(teb? teb->queue : 0);
1130 }
1131
1132 /***********************************************************************
1133  *           SetFastQueue  (KERNEL.624)
1134  */
1135 VOID WINAPI SetFastQueue16( DWORD thread, HANDLE hQueue )
1136 {
1137     TEB *teb = NULL;
1138     if ( !thread )
1139         teb = NtCurrentTeb();
1140     else if ( HIWORD(thread) )
1141         teb = THREAD_IdToTEB( thread );
1142     else if ( IsTask16( (HTASK16)thread ) )
1143         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1144
1145     if ( teb ) teb->queue = (HQUEUE16) hQueue;
1146 }
1147
1148 /***********************************************************************
1149  *           GetFastQueue  (KERNEL.625)
1150  */
1151 HANDLE WINAPI GetFastQueue16( void )
1152 {
1153     TEB *teb = NtCurrentTeb();
1154     if (!teb) return 0;
1155
1156     if (!teb->queue)
1157         Callout.InitThreadInput16( 0, THREAD_IsWin16(teb)? 4 : 5 );
1158
1159     if (!teb->queue)
1160         FIXME_(task)("(): should initialize thread-local queue, expect failure!\n" );
1161
1162     return (HANDLE)teb->queue;
1163 }
1164
1165 /***********************************************************************
1166  *           SwitchStackTo   (KERNEL.108)
1167  */
1168 void WINAPI SwitchStackTo16( WORD seg, WORD ptr, WORD top )
1169 {
1170     TDB *pTask;
1171     STACK16FRAME *oldFrame, *newFrame;
1172     INSTANCEDATA *pData;
1173     UINT16 copySize;
1174
1175     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1176     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
1177     TRACE_(task)("old=%04x:%04x new=%04x:%04x\n",
1178                   SELECTOROF( pTask->teb->cur_stack ),
1179                   OFFSETOF( pTask->teb->cur_stack ), seg, ptr );
1180
1181     /* Save the old stack */
1182
1183     oldFrame = THREAD_STACK16( pTask->teb );
1184     /* pop frame + args and push bp */
1185     pData->old_ss_sp   = pTask->teb->cur_stack + sizeof(STACK16FRAME)
1186                            + 2 * sizeof(WORD);
1187     *(WORD *)PTR_SEG_TO_LIN(pData->old_ss_sp) = oldFrame->bp;
1188     pData->stacktop    = top;
1189     pData->stackmin    = ptr;
1190     pData->stackbottom = ptr;
1191
1192     /* Switch to the new stack */
1193
1194     /* Note: we need to take the 3 arguments into account; otherwise,
1195      * the stack will underflow upon return from this function.
1196      */
1197     copySize = oldFrame->bp - OFFSETOF(pData->old_ss_sp);
1198     copySize += 3 * sizeof(WORD) + sizeof(STACK16FRAME);
1199     pTask->teb->cur_stack = PTR_SEG_OFF_TO_SEGPTR( seg, ptr - copySize );
1200     newFrame = THREAD_STACK16( pTask->teb );
1201
1202     /* Copy the stack frame and the local variables to the new stack */
1203
1204     memmove( newFrame, oldFrame, copySize );
1205     newFrame->bp = ptr;
1206     *(WORD *)PTR_SEG_OFF_TO_LIN( seg, ptr ) = 0;  /* clear previous bp */
1207 }
1208
1209
1210 /***********************************************************************
1211  *           SwitchStackBack   (KERNEL.109)
1212  */
1213 void WINAPI SwitchStackBack16( CONTEXT *context )
1214 {
1215     STACK16FRAME *oldFrame, *newFrame;
1216     INSTANCEDATA *pData;
1217
1218     if (!(pData = (INSTANCEDATA *)GlobalLock16(SELECTOROF(NtCurrentTeb()->cur_stack))))
1219         return;
1220     if (!pData->old_ss_sp)
1221     {
1222         WARN_(task)("No previous SwitchStackTo\n" );
1223         return;
1224     }
1225     TRACE_(task)("restoring stack %04x:%04x\n",
1226                  SELECTOROF(pData->old_ss_sp), OFFSETOF(pData->old_ss_sp) );
1227
1228     oldFrame = CURRENT_STACK16;
1229
1230     /* Pop bp from the previous stack */
1231
1232     BP_reg(context) = *(WORD *)PTR_SEG_TO_LIN(pData->old_ss_sp);
1233     pData->old_ss_sp += sizeof(WORD);
1234
1235     /* Switch back to the old stack */
1236
1237     NtCurrentTeb()->cur_stack = pData->old_ss_sp - sizeof(STACK16FRAME);
1238     SS_reg(context)  = SELECTOROF(pData->old_ss_sp);
1239     ESP_reg(context) = OFFSETOF(pData->old_ss_sp) - sizeof(DWORD); /*ret addr*/
1240     pData->old_ss_sp = 0;
1241
1242     /* Build a stack frame for the return */
1243
1244     newFrame = CURRENT_STACK16;
1245     newFrame->frame32 = oldFrame->frame32;
1246     if (TRACE_ON(relay))
1247     {
1248         newFrame->entry_ip = oldFrame->entry_ip;
1249         newFrame->entry_cs = oldFrame->entry_cs;
1250     }
1251 }
1252
1253
1254 /***********************************************************************
1255  *           GetTaskQueueDS  (KERNEL.118)
1256  */
1257 void WINAPI GetTaskQueueDS16( CONTEXT *context )
1258 {
1259     DS_reg(context) = GlobalHandleToSel16( GetTaskQueue16(0) );
1260 }
1261
1262
1263 /***********************************************************************
1264  *           GetTaskQueueES  (KERNEL.119)
1265  */
1266 void WINAPI GetTaskQueueES16( CONTEXT *context )
1267 {
1268     ES_reg(context) = GlobalHandleToSel16( GetTaskQueue16(0) );
1269 }
1270
1271
1272 /***********************************************************************
1273  *           GetCurrentTask   (KERNEL.36)
1274  */
1275 HTASK16 WINAPI GetCurrentTask(void)
1276 {
1277     return PROCESS_Current()->task;
1278 }
1279
1280 DWORD WINAPI WIN16_GetCurrentTask(void)
1281 {
1282     /* This is the version used by relay code; the first task is */
1283     /* returned in the high word of the result */
1284     return MAKELONG( GetCurrentTask(), hFirstTask );
1285 }
1286
1287
1288 /***********************************************************************
1289  *           GetCurrentPDB   (KERNEL.37)
1290  *
1291  * UNDOC: returns PSP of KERNEL in high word
1292  */
1293 DWORD WINAPI GetCurrentPDB16(void)
1294 {
1295     TDB *pTask;
1296
1297     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1298     return MAKELONG(pTask->hPDB, 0); /* FIXME */
1299 }
1300
1301
1302 /***********************************************************************
1303  *           GetInstanceData   (KERNEL.54)
1304  */
1305 INT16 WINAPI GetInstanceData16( HINSTANCE16 instance, WORD buffer, INT16 len )
1306 {
1307     char *ptr = (char *)GlobalLock16( instance );
1308     if (!ptr || !len) return 0;
1309     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1310     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1311     return len;
1312 }
1313
1314
1315 /***********************************************************************
1316  *           GetExeVersion   (KERNEL.105)
1317  */
1318 WORD WINAPI GetExeVersion16(void)
1319 {
1320     TDB *pTask;
1321
1322     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1323     return pTask->version;
1324 }
1325
1326
1327 /***********************************************************************
1328  *           SetErrorMode16   (KERNEL.107)
1329  */
1330 UINT16 WINAPI SetErrorMode16( UINT16 mode )
1331 {
1332     TDB *pTask;
1333     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1334     pTask->error_mode = mode;
1335     return SetErrorMode( mode );
1336 }
1337
1338
1339 /***********************************************************************
1340  *           GetDOSEnvironment   (KERNEL.131)
1341  */
1342 SEGPTR WINAPI GetDOSEnvironment16(void)
1343 {
1344     TDB *pTask;
1345
1346     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1347     return PTR_SEG_OFF_TO_SEGPTR( pTask->pdb.environment, 0 );
1348 }
1349
1350
1351 /***********************************************************************
1352  *           GetNumTasks   (KERNEL.152)
1353  */
1354 UINT16 WINAPI GetNumTasks16(void)
1355 {
1356     return nTaskCount;
1357 }
1358
1359
1360 /***********************************************************************
1361  *           GetTaskDS   (KERNEL.155)
1362  *
1363  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1364  * I don't think we need to bother with this.
1365  */
1366 HINSTANCE16 WINAPI GetTaskDS16(void)
1367 {
1368     TDB *pTask;
1369
1370     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1371     return pTask->hInstance;
1372 }
1373
1374 /***********************************************************************
1375  *           GetDummyModuleHandleDS   (KERNEL.602)
1376  */
1377 VOID WINAPI GetDummyModuleHandleDS16( CONTEXT *context )
1378 {
1379     TDB *pTask;
1380     WORD selector;
1381
1382     AX_reg( context ) = 0;
1383     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1384     if (!(pTask->flags & TDBF_WIN32)) return;
1385
1386     selector = GlobalHandleToSel16( pTask->hModule );
1387     DS_reg( context ) = selector;
1388     AX_reg( context ) = selector;
1389 }
1390
1391 /***********************************************************************
1392  *           IsTask   (KERNEL.320)
1393  */
1394 BOOL16 WINAPI IsTask16( HTASK16 hTask )
1395 {
1396     TDB *pTask;
1397
1398     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1399     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1400     return (pTask->magic == TDB_MAGIC);
1401 }
1402
1403
1404 /***********************************************************************
1405  *           SetTaskSignalProc   (KERNEL.38)
1406  *
1407  * Real 16-bit interface is provided by the THUNK_SetTaskSignalProc.
1408  */
1409 FARPROC16 WINAPI SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1410 {
1411     TDB *pTask;
1412     FARPROC16 oldProc;
1413
1414     if (!hTask) hTask = GetCurrentTask();
1415     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return NULL;
1416     oldProc = (FARPROC16)pTask->userhandler;
1417     pTask->userhandler = (USERSIGNALPROC)proc;
1418     return oldProc;
1419 }
1420
1421
1422 /***********************************************************************
1423  *           SetSigHandler   (KERNEL.140)
1424  */
1425 WORD WINAPI SetSigHandler16( FARPROC16 newhandler, FARPROC16* oldhandler,
1426                            UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1427 {
1428     FIXME_(task)("(%p,%p,%p,%d,%d), unimplemented.\n",
1429           newhandler,oldhandler,oldmode,newmode,flag );
1430
1431     if (flag != 1) return 0;
1432     if (!newmode) newhandler = NULL;  /* Default handler */
1433     if (newmode != 4)
1434     {
1435         TDB *pTask;
1436
1437         if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1438         if (oldmode) *oldmode = pTask->signal_flags;
1439         pTask->signal_flags = newmode;
1440         if (oldhandler) *oldhandler = pTask->sighandler;
1441         pTask->sighandler = newhandler;
1442     }
1443     return 0;
1444 }
1445
1446
1447 /***********************************************************************
1448  *           GlobalNotify   (KERNEL.154)
1449  *
1450  * Note that GlobalNotify does _not_ return the old NotifyProc
1451  * -- contrary to LocalNotify !!
1452  */
1453 VOID WINAPI GlobalNotify16( FARPROC16 proc )
1454 {
1455     TDB *pTask;
1456
1457     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1458     pTask->discardhandler = proc;
1459 }
1460
1461
1462 /***********************************************************************
1463  *           GetExePtr   (KERNEL.133)
1464  */
1465 static HMODULE16 GetExePtrHelper( HANDLE16 handle, HTASK16 *hTask )
1466 {
1467     char *ptr;
1468     HANDLE16 owner;
1469
1470       /* Check for module handle */
1471
1472     if (!(ptr = GlobalLock16( handle ))) return 0;
1473     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return handle;
1474
1475       /* Search for this handle inside all tasks */
1476
1477     *hTask = hFirstTask;
1478     while (*hTask)
1479     {
1480         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1481         if ((*hTask == handle) ||
1482             (pTask->hInstance == handle) ||
1483             (pTask->hQueue == handle) ||
1484             (pTask->hPDB == handle)) return pTask->hModule;
1485         *hTask = pTask->hNext;
1486     }
1487
1488       /* Check the owner for module handle */
1489
1490     owner = FarGetOwner16( handle );
1491     if (!(ptr = GlobalLock16( owner ))) return 0;
1492     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return owner;
1493
1494       /* Search for the owner inside all tasks */
1495
1496     *hTask = hFirstTask;
1497     while (*hTask)
1498     {
1499         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1500         if ((*hTask == owner) ||
1501             (pTask->hInstance == owner) ||
1502             (pTask->hQueue == owner) ||
1503             (pTask->hPDB == owner)) return pTask->hModule;
1504         *hTask = pTask->hNext;
1505     }
1506
1507     return 0;
1508 }
1509
1510 HMODULE16 WINAPI GetExePtr( HANDLE16 handle )
1511 {
1512     HTASK16 dummy;
1513     return GetExePtrHelper( handle, &dummy );
1514 }
1515
1516 void WINAPI WIN16_GetExePtr( CONTEXT *context )
1517 {
1518     WORD *stack = PTR_SEG_OFF_TO_LIN(SS_reg(context), SP_reg(context));
1519     HANDLE16 handle = (HANDLE16)stack[2];
1520     HTASK16 hTask = 0;
1521     HMODULE16 hModule;
1522
1523     hModule = GetExePtrHelper( handle, &hTask );
1524
1525     AX_reg(context) = CX_reg(context) = hModule;
1526     if (hTask) ES_reg(context) = hTask;
1527 }
1528
1529 /***********************************************************************
1530  *           TaskFirst   (TOOLHELP.63)
1531  */
1532 BOOL16 WINAPI TaskFirst16( TASKENTRY *lpte )
1533 {
1534     lpte->hNext = hFirstTask;
1535     return TaskNext16( lpte );
1536 }
1537
1538
1539 /***********************************************************************
1540  *           TaskNext   (TOOLHELP.64)
1541  */
1542 BOOL16 WINAPI TaskNext16( TASKENTRY *lpte )
1543 {
1544     TDB *pTask;
1545     INSTANCEDATA *pInstData;
1546
1547     TRACE_(toolhelp)("(%p): task=%04x\n", lpte, lpte->hNext );
1548     if (!lpte->hNext) return FALSE;
1549     pTask = (TDB *)GlobalLock16( lpte->hNext );
1550     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1551     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1552     lpte->hTask         = lpte->hNext;
1553     lpte->hTaskParent   = pTask->hParent;
1554     lpte->hInst         = pTask->hInstance;
1555     lpte->hModule       = pTask->hModule;
1556     lpte->wSS           = SELECTOROF( pTask->teb->cur_stack );
1557     lpte->wSP           = OFFSETOF( pTask->teb->cur_stack );
1558     lpte->wStackTop     = pInstData->stacktop;
1559     lpte->wStackMinimum = pInstData->stackmin;
1560     lpte->wStackBottom  = pInstData->stackbottom;
1561     lpte->wcEvents      = pTask->nEvents;
1562     lpte->hQueue        = pTask->hQueue;
1563     strncpy( lpte->szModule, pTask->module_name, 8 );
1564     lpte->szModule[8]   = '\0';
1565     lpte->wPSPOffset    = 0x100;  /*??*/
1566     lpte->hNext         = pTask->hNext;
1567     return TRUE;
1568 }
1569
1570
1571 /***********************************************************************
1572  *           TaskFindHandle   (TOOLHELP.65)
1573  */
1574 BOOL16 WINAPI TaskFindHandle16( TASKENTRY *lpte, HTASK16 hTask )
1575 {
1576     lpte->hNext = hTask;
1577     return TaskNext16( lpte );
1578 }
1579
1580
1581 /***********************************************************************
1582  *           GetAppCompatFlags16   (KERNEL.354)
1583  */
1584 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1585 {
1586     return GetAppCompatFlags( hTask );
1587 }
1588
1589
1590 /***********************************************************************
1591  *           GetAppCompatFlags32   (USER32.206)
1592  */
1593 DWORD WINAPI GetAppCompatFlags( HTASK hTask )
1594 {
1595     TDB *pTask;
1596
1597     if (!hTask) hTask = GetCurrentTask();
1598     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1599     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1600     return pTask->compat_flags;
1601 }