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/port.h"
  13 #include "wine/winbase16.h"
  14 #include "ntddk.h"
  15 #include "callback.h"
  16 #include "drive.h"
  17 #include "file.h"
  18 #include "global.h"
  19 #include "instance.h"
  20 #include "miscemu.h"
  21 #include "module.h"
  22 #include "queue.h"
  23 #include "selectors.h"
  24 #include "stackframe.h"
  25 #include "task.h"
  26 #include "thread.h"
  27 #include "toolhelp.h"
  28 #include "winnt.h"
  29 #include "syslevel.h"
  30 #include "winsock.h"
  31 #include "debugtools.h"
  32 #include "services.h"
  33 #include "server.h"
  34
  35
  36 DEFAULT_DEBUG_CHANNEL(task);
  37 DECLARE_DEBUG_CHANNEL(relay);
  38 DECLARE_DEBUG_CHANNEL(toolhelp);
  39
  40   /* Min. number of thunks allocated when creating a new segment */
  41 #define MIN_THUNKS  32
  42
  43
  44 static THHOOK DefaultThhook;
  45 THHOOK *pThhook = &DefaultThhook;
  46
  47 #define hCurrentTask (pThhook->CurTDB)
  48 #define hFirstTask   (pThhook->HeadTDB)
  49 #define hLockedTask  (pThhook->LockTDB)
  50
  51 static UINT16 nTaskCount = 0;
  52
  53 static HTASK initial_task;
  54
  55 /***********************************************************************
  56  *           TASK_InstallTHHook
  57  */
  58 void TASK_InstallTHHook( THHOOK *pNewThhook )
  59 {
  60      THHOOK *pOldThhook = pThhook;
  61
  62      pThhook = pNewThhook? pNewThhook : &DefaultThhook;
  63
  64      *pThhook = *pOldThhook;
  65 }
  66
  67 /***********************************************************************
  68  *           TASK_GetNextTask
  69  */
  70 HTASK16 TASK_GetNextTask( HTASK16 hTask )
  71 {
  72     TDB* pTask = (TDB*)GlobalLock16(hTask);
  73
  74     if (pTask->hNext) return pTask->hNext;
  75     return (hFirstTask != hTask) ? hFirstTask : 0;
  76 }
  77
  78 /***********************************************************************
  79  *           TASK_LinkTask
  80  */
  81 static void TASK_LinkTask( HTASK16 hTask )
  82 {
  83     HTASK16 *prevTask;
  84     TDB *pTask;
  85
  86     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
  87     prevTask = &hFirstTask;
  88     while (*prevTask)
  89     {
  90         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
  91         if (prevTaskPtr->priority >= pTask->priority) break;
  92         prevTask = &prevTaskPtr->hNext;
  93     }
  94     pTask->hNext = *prevTask;
  95     *prevTask = hTask;
  96     nTaskCount++;
  97 }
  98
  99
 100 /***********************************************************************
 101  *           TASK_UnlinkTask
 102  */
 103 static void TASK_UnlinkTask( HTASK16 hTask )
 104 {
 105     HTASK16 *prevTask;
 106     TDB *pTask;
 107
 108     prevTask = &hFirstTask;
 109     while (*prevTask && (*prevTask != hTask))
 110     {
 111         pTask = (TDB *)GlobalLock16( *prevTask );
 112         prevTask = &pTask->hNext;
 113     }
 114     if (*prevTask)
 115     {
 116         pTask = (TDB *)GlobalLock16( *prevTask );
 117         *prevTask = pTask->hNext;
 118         pTask->hNext = 0;
 119         nTaskCount--;
 120     }
 121 }
 122
 123
 124 /***********************************************************************
 125  *           TASK_CreateThunks
 126  *
 127  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 128  * and containing 'count' entries.
 129  */
 130 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 131 {
 132     int i;
 133     WORD free;
 134     THUNKS *pThunk;
 135
 136     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 137     pThunk->next = 0;
 138     pThunk->magic = THUNK_MAGIC;
 139     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 140     free = pThunk->free;
 141     for (i = 0; i < count-1; i++)
 142     {
 143         free += 8;  /* Offset of next thunk */
 144         pThunk->thunks[4*i] = free;
 145     }
 146     pThunk->thunks[4*i] = 0;  /* Last thunk */
 147 }
 148
 149
 150 /***********************************************************************
 151  *           TASK_AllocThunk
 152  *
 153  * Allocate a thunk for MakeProcInstance().
 154  */
 155 static SEGPTR TASK_AllocThunk( HTASK16 hTask )
 156 {
 157     TDB *pTask;
 158     THUNKS *pThunk;
 159     WORD sel, base;
 160
 161     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 162     sel = pTask->hCSAlias;
 163     pThunk = &pTask->thunks;
 164     base = (int)pThunk - (int)pTask;
 165     while (!pThunk->free)
 166     {
 167         sel = pThunk->next;
 168         if (!sel)  /* Allocate a new segment */
 169         {
 170             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 171                                 pTask->hPDB, WINE_LDT_FLAGS_CODE );
 172             if (!sel) return (SEGPTR)0;
 173             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 174             pThunk->next = sel;
 175         }
 176         pThunk = (THUNKS *)GlobalLock16( sel );
 177         base = 0;
 178     }
 179     base += pThunk->free;
 180     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 181     return MAKESEGPTR( sel, base );
 182 }
 183
 184
 185 /***********************************************************************
 186  *           TASK_FreeThunk
 187  *
 188  * Free a MakeProcInstance() thunk.
 189  */
 190 static BOOL TASK_FreeThunk( HTASK16 hTask, SEGPTR thunk )
 191 {
 192     TDB *pTask;
 193     THUNKS *pThunk;
 194     WORD sel, base;
 195
 196     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 197     sel = pTask->hCSAlias;
 198     pThunk = &pTask->thunks;
 199     base = (int)pThunk - (int)pTask;
 200     while (sel && (sel != HIWORD(thunk)))
 201     {
 202         sel = pThunk->next;
 203         pThunk = (THUNKS *)GlobalLock16( sel );
 204         base = 0;
 205     }
 206     if (!sel) return FALSE;
 207     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 208     pThunk->free = LOWORD(thunk) - base;
 209     return TRUE;
 210 }
 211
 212
 213 /***********************************************************************
 214  *           TASK_Create
 215  *
 216  * NOTE: This routine might be called by a Win32 thread. Thus, we need
 217  *       to be careful to protect global data structures. We do this
 218  *       by entering the Win16Lock while linking the task into the
 219  *       global task list.
 220  */
 221 static TDB *TASK_Create( NE_MODULE *pModule, UINT16 cmdShow, TEB *teb, LPCSTR cmdline, BYTE len )
 222 {
 223     HTASK16 hTask;
 224     TDB *pTask;
 225     char name[10];
 226
 227       /* Allocate the task structure */
 228
 229     hTask = GlobalAlloc16( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB) );
 230     if (!hTask) return NULL;
 231     pTask = (TDB *)GlobalLock16( hTask );
 232     FarSetOwner16( hTask, pModule->self );
 233
 234     /* Fill the task structure */
 235
 236     pTask->hSelf = hTask;
 237
 238     if (teb && teb->tibflags & TEBF_WIN32)
 239     {
 240         pTask->flags        |= TDBF_WIN32;
 241         pTask->hInstance     = pModule->self;
 242         pTask->hPrevInstance = 0;
 243         /* NOTE: for 16-bit tasks, the instance handles are updated later on
 244            in NE_InitProcess */
 245     }
 246
 247     pTask->version       = pModule->expected_version;
 248     pTask->hModule       = pModule->self;
 249     pTask->hParent       = GetCurrentTask();
 250     pTask->magic         = TDB_MAGIC;
 251     pTask->nCmdShow      = cmdShow;
 252     pTask->teb           = teb;
 253     pTask->curdrive      = DRIVE_GetCurrentDrive() | 0x80;
 254     strcpy( pTask->curdir, "\\" );
 255     lstrcpynA( pTask->curdir + 1, DRIVE_GetDosCwd( DRIVE_GetCurrentDrive() ),
 256                  sizeof(pTask->curdir) - 1 );
 257
 258       /* Create the thunks block */
 259
 260     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 261
 262       /* Copy the module name */
 263
 264     GetModuleName16( pModule->self, name, sizeof(name) );
 265     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 266
 267       /* Allocate a selector for the PDB */
 268
 269     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB16),
 270                                       pModule->self, WINE_LDT_FLAGS_DATA );
 271
 272       /* Fill the PDB */
 273
 274     pTask->pdb.int20 = 0x20cd;
 275     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 276     PUT_UA_DWORD(&pTask->pdb.dispatcher[1],
 277                  (DWORD)GetProcAddress16( GetModuleHandle16("KERNEL"), "DOS3Call" ));
 278     pTask->pdb.savedint22 = INT_GetPMHandler( 0x22 );
 279     pTask->pdb.savedint23 = INT_GetPMHandler( 0x23 );
 280     pTask->pdb.savedint24 = INT_GetPMHandler( 0x24 );
 281     pTask->pdb.fileHandlesPtr =
 282         MAKESEGPTR( GlobalHandleToSel16(pTask->hPDB), (int)&((PDB16 *)0)->fileHandles );
 283     pTask->pdb.hFileHandles = 0;
 284     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 285     /* FIXME: should we make a copy of the environment? */
 286     pTask->pdb.environment    = SELECTOROF(GetDOSEnvironment16());
 287     pTask->pdb.nbFiles        = 20;
 288
 289     /* Fill the command line */
 290
 291     if (!cmdline)
 292     {
 293         cmdline = GetCommandLineA();
 294         /* remove the first word (program name) */
 295         if (*cmdline == '"')
 296             if (!(cmdline = strchr( cmdline+1, '"' ))) cmdline = GetCommandLineA();
 297         while (*cmdline && (*cmdline != ' ') && (*cmdline != '\t')) cmdline++;
 298         while ((*cmdline == ' ') || (*cmdline == '\t')) cmdline++;
 299         len = strlen(cmdline);
 300     }
 301     if (len >= sizeof(pTask->pdb.cmdLine)) len = sizeof(pTask->pdb.cmdLine)-1;
 302     pTask->pdb.cmdLine[0] = len;
 303     memcpy( pTask->pdb.cmdLine + 1, cmdline, len );
 304     /* pTask->pdb.cmdLine[len+1] = 0; */
 305
 306     TRACE("module='%s' cmdline='%.*s' task=%04x\n", name, len, cmdline, hTask );
 307
 308       /* Get the compatibility flags */
 309
 310     pTask->compat_flags = GetProfileIntA( "Compatibility", name, 0 );
 311
 312       /* Allocate a code segment alias for the TDB */
 313
 314     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 315                                           sizeof(TDB), pTask->hPDB, WINE_LDT_FLAGS_CODE );
 316
 317       /* Default DTA overwrites command line */
 318
 319     pTask->dta = MAKESEGPTR( pTask->hPDB, (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 320
 321     /* Create scheduler event for 16-bit tasks */
 322
 323     if ( !(pTask->flags & TDBF_WIN32) )
 324         NtCreateEvent( &pTask->hEvent, EVENT_ALL_ACCESS, NULL, TRUE, FALSE );
 325
 326     /* Enter task handle into thread */
 327
 328     if (teb) teb->htask16 = hTask;
 329     if (!initial_task) initial_task = hTask;
 330
 331     return pTask;
 332 }
 333
 334
 335 /***********************************************************************
 336  *           TASK_DeleteTask
 337  */
 338 static void TASK_DeleteTask( HTASK16 hTask )
 339 {
 340     TDB *pTask;
 341     HGLOBAL16 hPDB;
 342
 343     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 344     hPDB = pTask->hPDB;
 345
 346     pTask->magic = 0xdead; /* invalidate signature */
 347
 348     /* Free the selector aliases */
 349
 350     GLOBAL_FreeBlock( pTask->hCSAlias );
 351     GLOBAL_FreeBlock( pTask->hPDB );
 352
 353     /* Free the task module */
 354
 355     FreeModule16( pTask->hModule );
 356
 357     /* Free the task structure itself */
 358
 359     GlobalFree16( hTask );
 360
 361     /* Free all memory used by this task (including the 32-bit stack, */
 362     /* the environment block and the thunk segments). */
 363
 364     GlobalFreeAll16( hPDB );
 365 }
 366
 367
 368 /***********************************************************************
 369  *           TASK_CreateMainTask
 370  *
 371  * Create a task for the main (32-bit) process.
 372  */
 373 void TASK_CreateMainTask(void)
 374 {
 375     TDB *pTask;
 376     STARTUPINFOA startup_info;
 377     UINT cmdShow = 1; /* SW_SHOWNORMAL but we don't want to include winuser.h here */
 378
 379     GetStartupInfoA( &startup_info );
 380     if (startup_info.dwFlags & STARTF_USESHOWWINDOW) cmdShow = startup_info.wShowWindow;
 381     pTask = TASK_Create( (NE_MODULE *)GlobalLock16( MapHModuleLS(GetModuleHandleA(0)) ),
 382                          cmdShow, NtCurrentTeb(), NULL, 0 );
 383     if (!pTask)
 384     {
 385         ERR("could not create task for main process\n");
 386         ExitProcess(1);
 387     }
 388
 389     /* Add the task to the linked list */
 390     /* (no need to get the win16 lock, we are the only thread at this point) */
 391     TASK_LinkTask( pTask->hSelf );
 392 }
 393
 394
 395 /* startup routine for a new 16-bit thread */
 396 static DWORD CALLBACK task_start( TDB *pTask )
 397 {
 398     DWORD ret;
 399
 400     NtCurrentTeb()->tibflags &= ~TEBF_WIN32;
 401     NtCurrentTeb()->htask16 = pTask->hSelf;
 402
 403     _EnterWin16Lock();
 404     TASK_LinkTask( pTask->hSelf );
 405     pTask->teb = NtCurrentTeb();
 406     ret = NE_StartTask();
 407     _LeaveWin16Lock();
 408     return ret;
 409 }
 410
 411
 412 /***********************************************************************
 413  *           TASK_SpawnTask
 414  *
 415  * Spawn a new 16-bit task.
 416  */
 417 HTASK TASK_SpawnTask( NE_MODULE *pModule, WORD cmdShow, LPCSTR cmdline, BYTE len, HANDLE *hThread )
 418 {
 419     TDB *pTask;
 420
 421     if (!(pTask = TASK_Create( pModule, cmdShow, NULL, cmdline, len ))) return 0;
 422     if (!(*hThread = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)task_start, pTask, 0, NULL )))
 423     {
 424         TASK_DeleteTask( pTask->hSelf );
 425         return 0;
 426     }
 427     return pTask->hSelf;
 428 }
 429
 430
 431 /***********************************************************************
 432  *           TASK_KillTask
 433  */
 434 void TASK_ExitTask(void)
 435 {
 436     TDB *pTask;
 437     DWORD lockCount;
 438
 439     /* Enter the Win16Lock to protect global data structures */
 440     _EnterWin16Lock();
 441
 442     pTask = (TDB *)GlobalLock16( GetCurrentTask() );
 443     if ( !pTask )
 444     {
 445         _LeaveWin16Lock();
 446         return;
 447     }
 448
 449     TRACE("Killing task %04x\n", pTask->hSelf );
 450
 451     /* Perform USER cleanup */
 452
 453     TASK_CallTaskSignalProc( USIG16_TERMINATION, pTask->hSelf );
 454     PROCESS_CallUserSignalProc( USIG_PROCESS_EXIT, 0 );
 455     PROCESS_CallUserSignalProc( USIG_THREAD_EXIT, 0 );
 456     PROCESS_CallUserSignalProc( USIG_PROCESS_DESTROY, 0 );
 457
 458     /* Remove the task from the list to be sure we never switch back to it */
 459     TASK_UnlinkTask( pTask->hSelf );
 460
 461     if (!nTaskCount || (nTaskCount == 1 && hFirstTask == initial_task))
 462     {
 463         TRACE("this is the last task, exiting\n" );
 464         ExitKernel16();
 465     }
 466
 467     if( nTaskCount )
 468     {
 469         TDB* p = (TDB *)GlobalLock16( hFirstTask );
 470         while( p )
 471         {
 472             if( p->hYieldTo == pTask->hSelf ) p->hYieldTo = 0;
 473             p = (TDB *)GlobalLock16( p->hNext );
 474         }
 475     }
 476
 477     pTask->nEvents = 0;
 478
 479     if ( hLockedTask == pTask->hSelf )
 480         hLockedTask = 0;
 481
 482     TASK_DeleteTask( pTask->hSelf );
 483
 484     /* ... schedule another one ... */
 485     TASK_Reschedule();
 486
 487     /* ... and completely release the Win16Lock, just in case. */
 488     ReleaseThunkLock( &lockCount );
 489 }
 490
 491 /***********************************************************************
 492  *           TASK_Reschedule
 493  *
 494  * This is where all the magic of task-switching happens!
 495  *
 496  * 16-bit Windows performs non-preemptive (cooperative) multitasking.
 497  * This means that each 16-bit task runs until it voluntarily yields
 498  * control, at which point the scheduler gets active and selects the
 499  * next task to run.
 500  *
 501  * In Wine, all processes, even 16-bit ones, are scheduled preemptively
 502  * by the standard scheduler of the underlying OS.  As many 16-bit apps
 503  * *rely* on the behaviour of the Windows scheduler, however, we have
 504  * to simulate that behaviour.
 505  *
 506  * This is achieved as follows: every 16-bit task is at time (except
 507  * during task creation and deletion) in one of two states: either it
 508  * is the one currently running, then the global variable hCurrentTask
 509  * contains its task handle, or it is not currently running, then it
 510  * is blocked on a special scheduler event, a global handle which
 511  * is stored in the task struct.
 512  *
 513  * When the current task yields control, this routine gets called. Its
 514  * purpose is to determine the next task to be active, signal the
 515  * scheduler event of that task, and then put the current task to sleep
 516  * waiting for *its* scheduler event to get signalled again.
 517  *
 518  * This routine can get called in a few other special situations as well:
 519  *
 520  * - On creation of a 16-bit task, the Unix process executing the task
 521  *   calls TASK_Reschedule once it has completed its initialization.
 522  *   At this point, the task needs to be blocked until its scheduler
 523  *   event is signalled the first time (this will be done by the parent
 524  *   process to get the task up and running).
 525  *
 526  * - When the task currently running terminates itself, this routine gets
 527  *   called and has to schedule another task, *without* blocking the
 528  *   terminating task.
 529  *
 530  * - When a 32-bit thread posts an event for a 16-bit task, it might be
 531  *   the case that *no* 16-bit task is currently running.  In this case
 532  *   the task that has now an event pending is to be scheduled.
 533  *
 534  */
 535 void TASK_Reschedule(void)
 536 {
 537     TDB *pOldTask = NULL, *pNewTask = NULL;
 538     HTASK16 hOldTask = 0, hNewTask = 0;
 539     enum { MODE_YIELD, MODE_SLEEP, MODE_WAKEUP } mode;
 540     DWORD lockCount;
 541
 542     _EnterWin16Lock();
 543
 544     /* Check what we need to do */
 545     hOldTask = GetCurrentTask();
 546     pOldTask = (TDB *)GlobalLock16( hOldTask );
 547     TRACE( "entered with hCurrentTask %04x by hTask %04x (pid %ld)\n",
 548            hCurrentTask, hOldTask, (long) getpid() );
 549
 550     if ( pOldTask && THREAD_IsWin16( NtCurrentTeb() ) )
 551     {
 552         /* We are called by an active (non-deleted) 16-bit task */
 553
 554         /* If we don't even have a current task, or else the current
 555            task has yielded, we'll need to schedule a new task and
 556            (possibly) put the calling task to sleep.  Otherwise, we
 557            only block the caller. */
 558
 559         if ( !hCurrentTask || hCurrentTask == hOldTask )
 560             mode = MODE_YIELD;
 561         else
 562             mode = MODE_SLEEP;
 563     }
 564     else
 565     {
 566         /* We are called by a deleted 16-bit task or a 32-bit thread */
 567
 568         /* The only situation where we need to do something is if we
 569            now do not have a current task.  Then, we'll need to wake up
 570            some task that has events pending. */
 571
 572         if ( !hCurrentTask || hCurrentTask == hOldTask )
 573             mode = MODE_WAKEUP;
 574         else
 575         {
 576             /* nothing to do */
 577             _LeaveWin16Lock();
 578             return;
 579         }
 580     }
 581
 582     /* Find a task to yield to: check for DirectedYield() */
 583     if ( mode == MODE_YIELD && pOldTask && pOldTask->hYieldTo )
 584     {
 585         hNewTask = pOldTask->hYieldTo;
 586         pNewTask = (TDB *)GlobalLock16( hNewTask );
 587         if( !pNewTask || !pNewTask->nEvents || !pNewTask->teb) hNewTask = 0;
 588         pOldTask->hYieldTo = 0;
 589     }
 590
 591     /* Find a task to yield to: check for pending events */
 592     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && !hNewTask )
 593     {
 594         hNewTask = hFirstTask;
 595         while (hNewTask)
 596         {
 597             pNewTask = (TDB *)GlobalLock16( hNewTask );
 598
 599             TRACE( "\ttask = %04x, events = %i\n", hNewTask, pNewTask->nEvents );
 600
 601             if (pNewTask->nEvents) break;
 602             hNewTask = pNewTask->hNext;
 603         }
 604         if (hLockedTask && (hNewTask != hLockedTask)) hNewTask = 0;
 605     }
 606
 607     /* If we are still the task with highest priority, just return ... */
 608     if ( mode == MODE_YIELD && hNewTask && hNewTask == hCurrentTask )
 609     {
 610         TRACE("returning to the current task (%04x)\n", hCurrentTask );
 611         _LeaveWin16Lock();
 612
 613         /* Allow Win32 threads to thunk down even while a Win16 task is
 614            in a tight PeekMessage() or Yield() loop ... */
 615         ReleaseThunkLock( &lockCount );
 616         RestoreThunkLock( lockCount );
 617         return;
 618     }
 619
 620     /* If no task to yield to found, suspend 16-bit scheduler ... */
 621     if ( mode == MODE_YIELD && !hNewTask )
 622     {
 623         TRACE("No currently active task\n");
 624         hCurrentTask = 0;
 625     }
 626
 627     /* If we found a task to wake up, do it ... */
 628     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && hNewTask )
 629     {
 630         TRACE("Switching to task %04x (%.8s)\n",
 631                       hNewTask, pNewTask->module_name );
 632
 633         pNewTask->priority++;
 634         TASK_UnlinkTask( hNewTask );
 635         TASK_LinkTask( hNewTask );
 636         pNewTask->priority--;
 637
 638         hCurrentTask = hNewTask;
 639         NtSetEvent( pNewTask->hEvent, NULL );
 640
 641         /* This is set just in case some app reads it ... */
 642         pNewTask->ss_sp = pNewTask->teb->cur_stack;
 643     }
 644
 645     /* If we need to put the current task to sleep, do it ... */
 646     if ( (mode == MODE_YIELD || mode == MODE_SLEEP) && hOldTask != hCurrentTask )
 647     {
 648         NtResetEvent( pOldTask->hEvent, NULL );
 649
 650         ReleaseThunkLock( &lockCount );
 651         SYSLEVEL_CheckNotLevel( 1 );
 652         WaitForSingleObject( pOldTask->hEvent, INFINITE );
 653         RestoreThunkLock( lockCount );
 654     }
 655
 656     _LeaveWin16Lock();
 657 }
 658
 659 /***********************************************************************
 660  *           InitTask  (KERNEL.91)
 661  *
 662  * Called by the application startup code.
 663  */
 664 void WINAPI InitTask16( CONTEXT86 *context )
 665 {
 666     TDB *pTask;
 667     INSTANCEDATA *pinstance;
 668     SEGPTR ptr;
 669
 670     context->Eax = 0;
 671     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
 672
 673     /* Note: we need to trust that BX/CX contain the stack/heap sizes,
 674        as some apps, notably Visual Basic apps, *modify* the heap/stack
 675        size of the instance data segment before calling InitTask() */
 676
 677     /* Initialize the INSTANCEDATA structure */
 678     pinstance = MapSL( MAKESEGPTR(CURRENT_DS, 0) );
 679     pinstance->stackmin    = OFFSETOF( pTask->teb->cur_stack ) + sizeof( STACK16FRAME );
 680     pinstance->stackbottom = pinstance->stackmin; /* yup, that's right. Confused me too. */
 681     pinstance->stacktop    = ( pinstance->stackmin > LOWORD(context->Ebx) ?
 682                                pinstance->stackmin - LOWORD(context->Ebx) : 0 ) + 150;
 683
 684     /* Initialize the local heap */
 685     if (LOWORD(context->Ecx))
 686         LocalInit16( GlobalHandleToSel16(pTask->hInstance), 0, LOWORD(context->Ecx) );
 687
 688     /* Initialize implicitly loaded DLLs */
 689     NE_InitializeDLLs( pTask->hModule );
 690     NE_DllProcessAttach( pTask->hModule );
 691
 692     /* Registers on return are:
 693      * ax     1 if OK, 0 on error
 694      * cx     stack limit in bytes
 695      * dx     cmdShow parameter
 696      * si     instance handle of the previous instance
 697      * di     instance handle of the new task
 698      * es:bx  pointer to command line inside PSP
 699      *
 700      * 0 (=%bp) is pushed on the stack
 701      */
 702     ptr = stack16_push( sizeof(WORD) );
 703     *(WORD *)MapSL(ptr) = 0;
 704     context->Esp -= 2;
 705
 706     context->Eax = 1;
 707
 708     if (!pTask->pdb.cmdLine[0]) context->Ebx = 0x80;
 709     else
 710     {
 711         LPBYTE p = &pTask->pdb.cmdLine[1];
 712         while ((*p == ' ') || (*p == '\t')) p++;
 713         context->Ebx = 0x80 + (p - pTask->pdb.cmdLine);
 714     }
 715     context->Ecx   = pinstance->stacktop;
 716     context->Edx   = pTask->nCmdShow;
 717     context->Esi   = (DWORD)pTask->hPrevInstance;
 718     context->Edi   = (DWORD)pTask->hInstance;
 719     context->SegEs = (WORD)pTask->hPDB;
 720 }
 721
 722
 723 /***********************************************************************
 724  *           WaitEvent  (KERNEL.30)
 725  */
 726 BOOL16 WINAPI WaitEvent16( HTASK16 hTask )
 727 {
 728     TDB *pTask;
 729
 730     if (!hTask) hTask = GetCurrentTask();
 731     pTask = (TDB *)GlobalLock16( hTask );
 732
 733     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 734     {
 735         FIXME("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 736         return TRUE;
 737     }
 738
 739     if (pTask->nEvents > 0)
 740     {
 741         pTask->nEvents--;
 742         return FALSE;
 743     }
 744     TASK_Reschedule();
 745
 746     /* When we get back here, we have an event */
 747
 748     if (pTask->nEvents > 0) pTask->nEvents--;
 749     return TRUE;
 750 }
 751
 752
 753 /***********************************************************************
 754  *           PostEvent  (KERNEL.31)
 755  */
 756 void WINAPI PostEvent16( HTASK16 hTask )
 757 {
 758     TDB *pTask;
 759
 760     if (!hTask) hTask = GetCurrentTask();
 761     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 762
 763     if ( !THREAD_IsWin16( pTask->teb ) )
 764     {
 765         FIXME("called for Win32 thread (%04x)!\n", pTask->teb->teb_sel );
 766         return;
 767     }
 768
 769     pTask->nEvents++;
 770
 771     /* If we are a 32-bit task, we might need to wake up the 16-bit scheduler */
 772     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 773         TASK_Reschedule();
 774 }
 775
 776
 777 /***********************************************************************
 778  *           SetPriority  (KERNEL.32)
 779  */
 780 void WINAPI SetPriority16( HTASK16 hTask, INT16 delta )
 781 {
 782     TDB *pTask;
 783     INT16 newpriority;
 784
 785     if (!hTask) hTask = GetCurrentTask();
 786     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 787     newpriority = pTask->priority + delta;
 788     if (newpriority < -32) newpriority = -32;
 789     else if (newpriority > 15) newpriority = 15;
 790
 791     pTask->priority = newpriority + 1;
 792     TASK_UnlinkTask( hTask );
 793     TASK_LinkTask( hTask );
 794     pTask->priority--;
 795 }
 796
 797
 798 /***********************************************************************
 799  *           LockCurrentTask  (KERNEL.33)
 800  */
 801 HTASK16 WINAPI LockCurrentTask16( BOOL16 bLock )
 802 {
 803     if (bLock) hLockedTask = GetCurrentTask();
 804     else hLockedTask = 0;
 805     return hLockedTask;
 806 }
 807
 808
 809 /***********************************************************************
 810  *           IsTaskLocked  (KERNEL.122)
 811  */
 812 HTASK16 WINAPI IsTaskLocked16(void)
 813 {
 814     return hLockedTask;
 815 }
 816
 817
 818 /***********************************************************************
 819  *           OldYield  (KERNEL.117)
 820  */
 821 void WINAPI OldYield16(void)
 822 {
 823     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 824
 825     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 826     {
 827         FIXME("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 828         return;
 829     }
 830
 831     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 832     TASK_Reschedule();
 833     if (pCurTask) pCurTask->nEvents--;
 834 }
 835
 836 /***********************************************************************
 837  *           WIN32_OldYield16  (KERNEL.447)
 838  */
 839 void WINAPI WIN32_OldYield16(void)
 840 {
 841    DWORD count;
 842
 843    ReleaseThunkLock(&count);
 844    RestoreThunkLock(count);
 845 }
 846
 847 /***********************************************************************
 848  *           DirectedYield  (KERNEL.150)
 849  */
 850 void WINAPI DirectedYield16( HTASK16 hTask )
 851 {
 852     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 853
 854     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 855     {
 856         FIXME("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 857         return;
 858     }
 859
 860     TRACE("%04x: DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 861
 862     pCurTask->hYieldTo = hTask;
 863     OldYield16();
 864
 865     TRACE("%04x: back from DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 866 }
 867
 868 /***********************************************************************
 869  *           Yield16  (KERNEL.29)
 870  */
 871 void WINAPI Yield16(void)
 872 {
 873     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 874
 875     if (pCurTask) pCurTask->hYieldTo = 0;
 876     if (pCurTask && pCurTask->hQueue && Callout.UserYield16) Callout.UserYield16();
 877     else OldYield16();
 878 }
 879
 880 /***********************************************************************
 881  *           KERNEL_490  (KERNEL.490)
 882  */
 883 HTASK16 WINAPI KERNEL_490( HTASK16 someTask )
 884 {
 885     if ( !someTask ) return 0;
 886
 887     FIXME("(%04x): stub\n", someTask );
 888     return 0;
 889 }
 890
 891 /***********************************************************************
 892  *           MakeProcInstance16  (KERNEL.51)
 893  */
 894 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 895 {
 896     BYTE *thunk,*lfunc;
 897     SEGPTR thunkaddr;
 898     WORD hInstanceSelector;
 899
 900     hInstanceSelector = GlobalHandleToSel16(hInstance);
 901
 902     TRACE("(%08lx, %04x);\n", (DWORD)func, hInstance);
 903
 904     if (!HIWORD(func)) {
 905       /* Win95 actually protects via SEH, but this is better for debugging */
 906       WARN("Ouch ! Called with invalid func 0x%08lx !\n", (DWORD)func);
 907       return (FARPROC16)0;
 908     }
 909
 910     if (hInstance)
 911     {
 912         if ( (!(hInstance & 4)) ||
 913              ((hInstance != 0xffff) && IS_SELECTOR_FREE(hInstance|7)) )
 914         {
 915             WARN("Invalid hInstance (%04x) passed to MakeProcInstance !\n",
 916                 hInstance);
 917             return 0;
 918         }
 919     }
 920
 921     if ( (GlobalHandleToSel16(CURRENT_DS) != hInstanceSelector)
 922       && (hInstance != 0)
 923       && (hInstance != 0xffff) )
 924     {
 925         /* calling MPI with a foreign DSEG is invalid ! */
 926         WARN("Problem with hInstance? Got %04x, using %04x instead\n",
 927                    hInstance,CURRENT_DS);
 928     }
 929
 930     /* Always use the DSEG that MPI was entered with.
 931      * We used to set hInstance to GetTaskDS16(), but this should be wrong
 932      * as CURRENT_DS provides the DSEG value we need.
 933      * ("calling" DS, *not* "task" DS !) */
 934     hInstanceSelector = CURRENT_DS;
 935     hInstance = GlobalHandle16(hInstanceSelector);
 936
 937     /* no thunking for DLLs */
 938     if (NE_GetPtr(FarGetOwner16(hInstance))->flags & NE_FFLAGS_LIBMODULE)
 939         return func;
 940
 941     thunkaddr = TASK_AllocThunk( GetCurrentTask() );
 942     if (!thunkaddr) return (FARPROC16)0;
 943     thunk = MapSL( thunkaddr );
 944     lfunc = MapSL( (SEGPTR)func );
 945
 946     TRACE("(%08lx,%04x): got thunk %08lx\n",
 947           (DWORD)func, hInstance, (DWORD)thunkaddr );
 948     if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) || /* movw %ds, %ax */
 949         ((lfunc[0]==0x1e) && (lfunc[1]==0x58))    /* pushw %ds, popw %ax */
 950     ) {
 951         WARN("This was the (in)famous \"thunk useless\" warning. We thought we have to overwrite with nop;nop;, but this isn't true.\n");
 952     }
 953
 954     *thunk++ = 0xb8;    /* movw instance, %ax */
 955     *thunk++ = (BYTE)(hInstanceSelector & 0xff);
 956     *thunk++ = (BYTE)(hInstanceSelector >> 8);
 957     *thunk++ = 0xea;    /* ljmp func */
 958     *(DWORD *)thunk = (DWORD)func;
 959     return (FARPROC16)thunkaddr;
 960     /* CX reg indicates if thunkaddr != NULL, implement if needed */
 961 }
 962
 963
 964 /***********************************************************************
 965  *           FreeProcInstance16  (KERNEL.52)
 966  */
 967 void WINAPI FreeProcInstance16( FARPROC16 func )
 968 {
 969     TRACE("(%08lx)\n", (DWORD)func );
 970     TASK_FreeThunk( GetCurrentTask(), (SEGPTR)func );
 971 }
 972
 973 /**********************************************************************
 974  *          TASK_GetCodeSegment
 975  *
 976  * Helper function for GetCodeHandle/GetCodeInfo: Retrieve the module
 977  * and logical segment number of a given code segment.
 978  *
 979  * 'proc' either *is* already a pair of module handle and segment number,
 980  * in which case there's nothing to do.  Otherwise, it is a pointer to
 981  * a function, and we need to retrieve the code segment.  If the pointer
 982  * happens to point to a thunk, we'll retrieve info about the code segment
 983  * where the function pointed to by the thunk resides, not the thunk itself.
 984  *
 985  * FIXME: if 'proc' is a SNOOP16 return stub, we should retrieve info about
 986  *        the function the snoop code will return to ...
 987  *
 988  */
 989 static BOOL TASK_GetCodeSegment( FARPROC16 proc, NE_MODULE **ppModule,
 990                                  SEGTABLEENTRY **ppSeg, int *pSegNr )
 991 {
 992     NE_MODULE *pModule = NULL;
 993     SEGTABLEENTRY *pSeg = NULL;
 994     int segNr=0;
 995
 996     /* Try pair of module handle / segment number */
 997     pModule = (NE_MODULE *) GlobalLock16( HIWORD( proc ) );
 998     if ( pModule && pModule->magic == IMAGE_OS2_SIGNATURE )
 999     {
1000         segNr = LOWORD( proc );
1001         if ( segNr && segNr <= pModule->seg_count )
1002             pSeg = NE_SEG_TABLE( pModule ) + segNr-1;
1003     }
1004
1005     /* Try thunk or function */
1006     else
1007     {
1008         BYTE *thunk = MapSL( (SEGPTR)proc );
1009         WORD selector;
1010
1011         if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1012             selector = thunk[6] + (thunk[7] << 8);
1013         else
1014             selector = HIWORD( proc );
1015
1016         pModule = NE_GetPtr( GlobalHandle16( selector ) );
1017         pSeg = pModule? NE_SEG_TABLE( pModule ) : NULL;
1018
1019         if ( pModule )
1020             for ( segNr = 1; segNr <= pModule->seg_count; segNr++, pSeg++ )
1021                 if ( GlobalHandleToSel16(pSeg->hSeg) == selector )
1022                     break;
1023
1024         if ( pModule && segNr > pModule->seg_count )
1025             pSeg = NULL;
1026     }
1027
1028     /* Abort if segment not found */
1029
1030     if ( !pModule || !pSeg )
1031         return FALSE;
1032
1033     /* Return segment data */
1034
1035     if ( ppModule ) *ppModule = pModule;
1036     if ( ppSeg    ) *ppSeg    = pSeg;
1037     if ( pSegNr   ) *pSegNr   = segNr;
1038
1039     return TRUE;
1040 }
1041
1042 /**********************************************************************
1043  *          GetCodeHandle    (KERNEL.93)
1044  */
1045 HANDLE16 WINAPI GetCodeHandle16( FARPROC16 proc )
1046 {
1047     SEGTABLEENTRY *pSeg;
1048
1049     if ( !TASK_GetCodeSegment( proc, NULL, &pSeg, NULL ) )
1050         return (HANDLE16)0;
1051
1052     return pSeg->hSeg;
1053 }
1054
1055 /**********************************************************************
1056  *          GetCodeInfo    (KERNEL.104)
1057  */
1058 BOOL16 WINAPI GetCodeInfo16( FARPROC16 proc, SEGINFO *segInfo )
1059 {
1060     NE_MODULE *pModule;
1061     SEGTABLEENTRY *pSeg;
1062     int segNr;
1063
1064     if ( !TASK_GetCodeSegment( proc, &pModule, &pSeg, &segNr ) )
1065         return FALSE;
1066
1067     /* Fill in segment information */
1068
1069     segInfo->offSegment = pSeg->filepos;
1070     segInfo->cbSegment  = pSeg->size;
1071     segInfo->flags      = pSeg->flags;
1072     segInfo->cbAlloc    = pSeg->minsize;
1073     segInfo->h          = pSeg->hSeg;
1074     segInfo->alignShift = pModule->alignment;
1075
1076     if ( segNr == pModule->dgroup )
1077         segInfo->cbAlloc += pModule->heap_size + pModule->stack_size;
1078
1079     /* Return module handle in %es */
1080
1081     CURRENT_STACK16->es = GlobalHandleToSel16( pModule->self );
1082
1083     return TRUE;
1084 }
1085
1086
1087 /**********************************************************************
1088  *          DefineHandleTable16    (KERNEL.94)
1089  */
1090 BOOL16 WINAPI DefineHandleTable16( WORD wOffset )
1091 {
1092     FIXME("(%04x): stub ?\n", wOffset);
1093     return TRUE;
1094 }
1095
1096
1097 /***********************************************************************
1098  *           SetTaskQueue  (KERNEL.34)
1099  */
1100 HQUEUE16 WINAPI SetTaskQueue16( HTASK16 hTask, HQUEUE16 hQueue )
1101 {
1102     HQUEUE16 hPrev;
1103     TDB *pTask;
1104
1105     if (!hTask) hTask = GetCurrentTask();
1106     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1107
1108     hPrev = pTask->hQueue;
1109     pTask->hQueue = hQueue;
1110
1111     return hPrev;
1112 }
1113
1114
1115 /***********************************************************************
1116  *           GetTaskQueue  (KERNEL.35)
1117  */
1118 HQUEUE16 WINAPI GetTaskQueue16( HTASK16 hTask )
1119 {
1120     TDB *pTask;
1121
1122     if (!hTask) hTask = GetCurrentTask();
1123     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1124     return pTask->hQueue;
1125 }
1126
1127 /***********************************************************************
1128  *           SetThreadQueue  (KERNEL.463)
1129  */
1130 HQUEUE16 WINAPI SetThreadQueue16( DWORD thread, HQUEUE16 hQueue )
1131 {
1132     TEB *teb = thread? THREAD_IdToTEB( thread ) : NtCurrentTeb();
1133     HQUEUE16 oldQueue = teb? teb->queue : 0;
1134
1135     if ( teb )
1136     {
1137         teb->queue = hQueue;
1138
1139         if ( GetTaskQueue16( teb->htask16 ) == oldQueue )
1140             SetTaskQueue16( teb->htask16, hQueue );
1141     }
1142
1143     return oldQueue;
1144 }
1145
1146 /***********************************************************************
1147  *           GetThreadQueue  (KERNEL.464)
1148  */
1149 HQUEUE16 WINAPI GetThreadQueue16( DWORD thread )
1150 {
1151     TEB *teb = NULL;
1152     if ( !thread )
1153         teb = NtCurrentTeb();
1154     else if ( HIWORD(thread) )
1155         teb = THREAD_IdToTEB( thread );
1156     else if ( IsTask16( (HTASK16)thread ) )
1157         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1158
1159     return (HQUEUE16)(teb? teb->queue : 0);
1160 }
1161
1162 /***********************************************************************
1163  *           SetFastQueue  (KERNEL.624)
1164  */
1165 VOID WINAPI SetFastQueue16( DWORD thread, HANDLE hQueue )
1166 {
1167     TEB *teb = NULL;
1168     if ( !thread )
1169         teb = NtCurrentTeb();
1170     else if ( HIWORD(thread) )
1171         teb = THREAD_IdToTEB( thread );
1172     else if ( IsTask16( (HTASK16)thread ) )
1173         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1174
1175     if ( teb ) teb->queue = (HQUEUE16) hQueue;
1176 }
1177
1178 /***********************************************************************
1179  *           GetFastQueue  (KERNEL.625)
1180  */
1181 HANDLE WINAPI GetFastQueue16( void )
1182 {
1183     TEB *teb = NtCurrentTeb();
1184     if (!teb) return 0;
1185
1186     if (!teb->queue)
1187     {
1188         if (!Callout.InitThreadInput16)
1189         {
1190             THUNK_InitCallout();
1191             if (!Callout.InitThreadInput16)
1192             {
1193                 FIXME("InitThreadInput16 callout not found, trouble ahead\n");
1194                 return 0;
1195             }
1196         }
1197         Callout.InitThreadInput16( 0, THREAD_IsWin16(teb)? 4 : 5 );
1198
1199         if (!teb->queue)
1200             FIXME("(): should initialize thread-local queue, expect failure!\n" );
1201     }
1202
1203     return (HANDLE)teb->queue;
1204 }
1205
1206 /***********************************************************************
1207  *           SwitchStackTo   (KERNEL.108)
1208  */
1209 void WINAPI SwitchStackTo16( WORD seg, WORD ptr, WORD top )
1210 {
1211     TDB *pTask;
1212     STACK16FRAME *oldFrame, *newFrame;
1213     INSTANCEDATA *pData;
1214     UINT16 copySize;
1215
1216     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1217     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
1218     TRACE("old=%04x:%04x new=%04x:%04x\n",
1219           SELECTOROF( pTask->teb->cur_stack ),
1220           OFFSETOF( pTask->teb->cur_stack ), seg, ptr );
1221
1222     /* Save the old stack */
1223
1224     oldFrame = THREAD_STACK16( pTask->teb );
1225     /* pop frame + args and push bp */
1226     pData->old_ss_sp   = pTask->teb->cur_stack + sizeof(STACK16FRAME)
1227                            + 2 * sizeof(WORD);
1228     *(WORD *)MapSL(pData->old_ss_sp) = oldFrame->bp;
1229     pData->stacktop    = top;
1230     pData->stackmin    = ptr;
1231     pData->stackbottom = ptr;
1232
1233     /* Switch to the new stack */
1234
1235     /* Note: we need to take the 3 arguments into account; otherwise,
1236      * the stack will underflow upon return from this function.
1237      */
1238     copySize = oldFrame->bp - OFFSETOF(pData->old_ss_sp);
1239     copySize += 3 * sizeof(WORD) + sizeof(STACK16FRAME);
1240     pTask->teb->cur_stack = MAKESEGPTR( seg, ptr - copySize );
1241     newFrame = THREAD_STACK16( pTask->teb );
1242
1243     /* Copy the stack frame and the local variables to the new stack */
1244
1245     memmove( newFrame, oldFrame, copySize );
1246     newFrame->bp = ptr;
1247     *(WORD *)MapSL( MAKESEGPTR( seg, ptr ) ) = 0;  /* clear previous bp */
1248 }
1249
1250
1251 /***********************************************************************
1252  *           SwitchStackBack   (KERNEL.109)
1253  */
1254 void WINAPI SwitchStackBack16( CONTEXT86 *context )
1255 {
1256     STACK16FRAME *oldFrame, *newFrame;
1257     INSTANCEDATA *pData;
1258
1259     if (!(pData = (INSTANCEDATA *)GlobalLock16(SELECTOROF(NtCurrentTeb()->cur_stack))))
1260         return;
1261     if (!pData->old_ss_sp)
1262     {
1263         WARN("No previous SwitchStackTo\n" );
1264         return;
1265     }
1266     TRACE("restoring stack %04x:%04x\n",
1267           SELECTOROF(pData->old_ss_sp), OFFSETOF(pData->old_ss_sp) );
1268
1269     oldFrame = CURRENT_STACK16;
1270
1271     /* Pop bp from the previous stack */
1272
1273     BP_reg(context) = *(WORD *)MapSL(pData->old_ss_sp);
1274     pData->old_ss_sp += sizeof(WORD);
1275
1276     /* Switch back to the old stack */
1277
1278     NtCurrentTeb()->cur_stack = pData->old_ss_sp - sizeof(STACK16FRAME);
1279     context->SegSs = SELECTOROF(pData->old_ss_sp);
1280     context->Esp   = OFFSETOF(pData->old_ss_sp) - sizeof(DWORD); /*ret addr*/
1281     pData->old_ss_sp = 0;
1282
1283     /* Build a stack frame for the return */
1284
1285     newFrame = CURRENT_STACK16;
1286     newFrame->frame32     = oldFrame->frame32;
1287     newFrame->module_cs   = oldFrame->module_cs;
1288     newFrame->callfrom_ip = oldFrame->callfrom_ip;
1289     newFrame->entry_ip    = oldFrame->entry_ip;
1290 }
1291
1292
1293 /***********************************************************************
1294  *           GetTaskQueueDS16  (KERNEL.118)
1295  */
1296 void WINAPI GetTaskQueueDS16(void)
1297 {
1298     CURRENT_STACK16->ds = GlobalHandleToSel16( GetTaskQueue16(0) );
1299 }
1300
1301
1302 /***********************************************************************
1303  *           GetTaskQueueES16  (KERNEL.119)
1304  */
1305 void WINAPI GetTaskQueueES16(void)
1306 {
1307     CURRENT_STACK16->es = GlobalHandleToSel16( GetTaskQueue16(0) );
1308 }
1309
1310
1311 /***********************************************************************
1312  *           GetCurrentTask   (KERNEL.36)
1313  */
1314 HTASK16 WINAPI GetCurrentTask(void)
1315 {
1316     return NtCurrentTeb()->htask16;
1317 }
1318
1319 DWORD WINAPI WIN16_GetCurrentTask(void)
1320 {
1321     /* This is the version used by relay code; the first task is */
1322     /* returned in the high word of the result */
1323     return MAKELONG( GetCurrentTask(), hFirstTask );
1324 }
1325
1326
1327 /***********************************************************************
1328  *           GetCurrentPDB   (KERNEL.37)
1329  *
1330  * UNDOC: returns PSP of KERNEL in high word
1331  */
1332 DWORD WINAPI GetCurrentPDB16(void)
1333 {
1334     TDB *pTask;
1335
1336     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1337     return MAKELONG(pTask->hPDB, 0); /* FIXME */
1338 }
1339
1340
1341 /***********************************************************************
1342  *           GetCurPID16   (KERNEL.157)
1343  */
1344 DWORD WINAPI GetCurPID16( DWORD unused )
1345 {
1346     return 0;
1347 }
1348
1349
1350 /***********************************************************************
1351  *           GetInstanceData   (KERNEL.54)
1352  */
1353 INT16 WINAPI GetInstanceData16( HINSTANCE16 instance, WORD buffer, INT16 len )
1354 {
1355     char *ptr = (char *)GlobalLock16( instance );
1356     if (!ptr || !len) return 0;
1357     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1358     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1359     return len;
1360 }
1361
1362
1363 /***********************************************************************
1364  *           GetExeVersion   (KERNEL.105)
1365  */
1366 WORD WINAPI GetExeVersion16(void)
1367 {
1368     TDB *pTask;
1369
1370     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1371     return pTask->version;
1372 }
1373
1374
1375 /***********************************************************************
1376  *           SetErrorMode16   (KERNEL.107)
1377  */
1378 UINT16 WINAPI SetErrorMode16( UINT16 mode )
1379 {
1380     TDB *pTask;
1381     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1382     pTask->error_mode = mode;
1383     return SetErrorMode( mode );
1384 }
1385
1386
1387 /***********************************************************************
1388  *           GetNumTasks   (KERNEL.152)
1389  */
1390 UINT16 WINAPI GetNumTasks16(void)
1391 {
1392     return nTaskCount;
1393 }
1394
1395
1396 /***********************************************************************
1397  *           GetTaskDS   (KERNEL.155)
1398  *
1399  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1400  * I don't think we need to bother with this.
1401  */
1402 HINSTANCE16 WINAPI GetTaskDS16(void)
1403 {
1404     TDB *pTask;
1405
1406     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1407     return GlobalHandleToSel16(pTask->hInstance);
1408 }
1409
1410 /***********************************************************************
1411  *           GetDummyModuleHandleDS   (KERNEL.602)
1412  */
1413 WORD WINAPI GetDummyModuleHandleDS16(void)
1414 {
1415     TDB *pTask;
1416     WORD selector;
1417
1418     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1419     if (!(pTask->flags & TDBF_WIN32)) return 0;
1420     selector = GlobalHandleToSel16( pTask->hModule );
1421     CURRENT_DS = selector;
1422     return selector;
1423 }
1424
1425 /***********************************************************************
1426  *           IsTask   (KERNEL.320)
1427  *           IsTask16 (KERNEL32.@)
1428  */
1429 BOOL16 WINAPI IsTask16( HTASK16 hTask )
1430 {
1431     TDB *pTask;
1432
1433     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1434     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1435     return (pTask->magic == TDB_MAGIC);
1436 }
1437
1438
1439 /***********************************************************************
1440  *           IsWinOldApTask16   (KERNEL.158)
1441  */
1442 BOOL16 WINAPI IsWinOldApTask16( HTASK16 hTask )
1443 {
1444     /* should return bit 0 of byte 0x48 in PSP */
1445     return FALSE;
1446 }
1447
1448 /***********************************************************************
1449  *           SetTaskSignalProc   (KERNEL.38)
1450  */
1451 FARPROC16 WINAPI SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1452 {
1453     TDB *pTask;
1454     FARPROC16 oldProc;
1455
1456     if (!hTask) hTask = GetCurrentTask();
1457     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return NULL;
1458     oldProc = pTask->userhandler;
1459     pTask->userhandler = proc;
1460     return oldProc;
1461 }
1462
1463 /***********************************************************************
1464  *           TASK_CallTaskSignalProc
1465  */
1466 /* ### start build ### */
1467 extern WORD CALLBACK TASK_CallTo16_word_wwwww(FARPROC16,WORD,WORD,WORD,WORD,WORD);
1468 /* ### stop build ### */
1469 void TASK_CallTaskSignalProc( UINT16 uCode, HANDLE16 hTaskOrModule )
1470 {
1471     TDB *pTask = (TDB *)GlobalLock16( GetCurrentTask() );
1472     if ( !pTask || !pTask->userhandler ) return;
1473
1474     TASK_CallTo16_word_wwwww( pTask->userhandler,
1475                               hTaskOrModule, uCode, 0,
1476                               pTask->hInstance, pTask->hQueue );
1477 }
1478
1479 /***********************************************************************
1480  *           SetSigHandler   (KERNEL.140)
1481  */
1482 WORD WINAPI SetSigHandler16( FARPROC16 newhandler, FARPROC16* oldhandler,
1483                            UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1484 {
1485     FIXME("(%p,%p,%p,%d,%d), unimplemented.\n",
1486           newhandler,oldhandler,oldmode,newmode,flag );
1487
1488     if (flag != 1) return 0;
1489     if (!newmode) newhandler = NULL;  /* Default handler */
1490     if (newmode != 4)
1491     {
1492         TDB *pTask;
1493
1494         if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1495         if (oldmode) *oldmode = pTask->signal_flags;
1496         pTask->signal_flags = newmode;
1497         if (oldhandler) *oldhandler = pTask->sighandler;
1498         pTask->sighandler = newhandler;
1499     }
1500     return 0;
1501 }
1502
1503
1504 /***********************************************************************
1505  *           GlobalNotify   (KERNEL.154)
1506  *
1507  * Note that GlobalNotify does _not_ return the old NotifyProc
1508  * -- contrary to LocalNotify !!
1509  */
1510 VOID WINAPI GlobalNotify16( FARPROC16 proc )
1511 {
1512     TDB *pTask;
1513
1514     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1515     pTask->discardhandler = proc;
1516 }
1517
1518
1519 /***********************************************************************
1520  *           GetExePtr   (KERNEL.133)
1521  */
1522 static inline HMODULE16 GetExePtrHelper( HANDLE16 handle, HTASK16 *hTask )
1523 {
1524     char *ptr;
1525     HANDLE16 owner;
1526
1527       /* Check for module handle */
1528
1529     if (!(ptr = GlobalLock16( handle ))) return 0;
1530     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return handle;
1531
1532       /* Search for this handle inside all tasks */
1533
1534     *hTask = hFirstTask;
1535     while (*hTask)
1536     {
1537         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1538         if ((*hTask == handle) ||
1539             (pTask->hInstance == handle) ||
1540             (pTask->hQueue == handle) ||
1541             (pTask->hPDB == handle)) return pTask->hModule;
1542         *hTask = pTask->hNext;
1543     }
1544
1545       /* Check the owner for module handle */
1546
1547     owner = FarGetOwner16( handle );
1548     if (!(ptr = GlobalLock16( owner ))) return 0;
1549     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return owner;
1550
1551       /* Search for the owner inside all tasks */
1552
1553     *hTask = hFirstTask;
1554     while (*hTask)
1555     {
1556         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1557         if ((*hTask == owner) ||
1558             (pTask->hInstance == owner) ||
1559             (pTask->hQueue == owner) ||
1560             (pTask->hPDB == owner)) return pTask->hModule;
1561         *hTask = pTask->hNext;
1562     }
1563
1564     return 0;
1565 }
1566
1567 /**********************************************************************/
1568
1569 HMODULE16 WINAPI WIN16_GetExePtr( HANDLE16 handle )
1570 {
1571     HTASK16 hTask = 0;
1572     HMODULE16 hModule = GetExePtrHelper( handle, &hTask );
1573     STACK16FRAME *frame = CURRENT_STACK16;
1574     frame->ecx = hModule;
1575     if (hTask) frame->es = hTask;
1576     return hModule;
1577 }
1578
1579 /**********************************************************************/
1580
1581 HMODULE16 WINAPI GetExePtr( HANDLE16 handle )
1582 {
1583     HTASK16 hTask = 0;
1584     return GetExePtrHelper( handle, &hTask );
1585 }
1586
1587
1588 /***********************************************************************
1589  *           TaskFirst   (TOOLHELP.63)
1590  */
1591 BOOL16 WINAPI TaskFirst16( TASKENTRY *lpte )
1592 {
1593     lpte->hNext = hFirstTask;
1594     return TaskNext16( lpte );
1595 }
1596
1597
1598 /***********************************************************************
1599  *           TaskNext   (TOOLHELP.64)
1600  */
1601 BOOL16 WINAPI TaskNext16( TASKENTRY *lpte )
1602 {
1603     TDB *pTask;
1604     INSTANCEDATA *pInstData;
1605
1606     TRACE_(toolhelp)("(%p): task=%04x\n", lpte, lpte->hNext );
1607     if (!lpte->hNext) return FALSE;
1608
1609     /* make sure that task and hInstance are valid (skip initial Wine task !) */
1610     while (1) {
1611         pTask = (TDB *)GlobalLock16( lpte->hNext );
1612         if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1613         if (pTask->hInstance)
1614             break;
1615         lpte->hNext = pTask->hNext;
1616     }
1617     pInstData = MapSL( MAKESEGPTR( GlobalHandleToSel16(pTask->hInstance), 0 ) );
1618     lpte->hTask         = lpte->hNext;
1619     lpte->hTaskParent   = pTask->hParent;
1620     lpte->hInst         = pTask->hInstance;
1621     lpte->hModule       = pTask->hModule;
1622     lpte->wSS           = SELECTOROF( pTask->teb->cur_stack );
1623     lpte->wSP           = OFFSETOF( pTask->teb->cur_stack );
1624     lpte->wStackTop     = pInstData->stacktop;
1625     lpte->wStackMinimum = pInstData->stackmin;
1626     lpte->wStackBottom  = pInstData->stackbottom;
1627     lpte->wcEvents      = pTask->nEvents;
1628     lpte->hQueue        = pTask->hQueue;
1629     lstrcpynA( lpte->szModule, pTask->module_name, sizeof(lpte->szModule) );
1630     lpte->wPSPOffset    = 0x100;  /*??*/
1631     lpte->hNext         = pTask->hNext;
1632     return TRUE;
1633 }
1634
1635
1636 /***********************************************************************
1637  *           TaskFindHandle   (TOOLHELP.65)
1638  */
1639 BOOL16 WINAPI TaskFindHandle16( TASKENTRY *lpte, HTASK16 hTask )
1640 {
1641     lpte->hNext = hTask;
1642     return TaskNext16( lpte );
1643 }
1644
1645
1646 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND hWnd, LPCSTR text, LPCSTR title, UINT type);
1647
1648 /**************************************************************************
1649  *           FatalAppExit16   (KERNEL.137)
1650  */
1651 void WINAPI FatalAppExit16( UINT16 action, LPCSTR str )
1652 {
1653     TDB *pTask = (TDB *)GlobalLock16( GetCurrentTask() );
1654
1655     if (!pTask || !(pTask->error_mode & SEM_NOGPFAULTERRORBOX))
1656     {
1657         HMODULE mod = GetModuleHandleA( "user32.dll" );
1658         if (mod)
1659         {
1660             MessageBoxA_funcptr pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
1661             if (pMessageBoxA)
1662             {
1663                 pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
1664                 goto done;
1665             }
1666         }
1667         ERR( "%s\n", debugstr_a(str) );
1668     }
1669  done:
1670     ExitThread(0xff);
1671 }
1672
1673
1674 /***********************************************************************
1675  *           TerminateApp16   (TOOLHELP.77)
1676  *
1677  * See "Undocumented Windows".
1678  */
1679 void WINAPI TerminateApp16(HTASK16 hTask, WORD wFlags)
1680 {
1681     if (hTask && hTask != GetCurrentTask())
1682     {
1683         FIXME("cannot terminate task %x\n", hTask);
1684         return;
1685     }
1686
1687     if (wFlags & NO_UAE_BOX)
1688     {
1689         UINT16 old_mode;
1690         old_mode = SetErrorMode16(0);
1691         SetErrorMode16(old_mode|SEM_NOGPFAULTERRORBOX);
1692     }
1693     FatalAppExit16( 0, NULL );
1694
1695     /* hmm, we're still alive ?? */
1696
1697     /* check undocumented flag */
1698     if (!(wFlags & 0x8000))
1699         TASK_CallTaskSignalProc( USIG16_TERMINATION, hTask );
1700
1701     /* UndocWin says to call int 0x21/0x4c exit=0xff here,
1702        but let's just call ExitThread */
1703     ExitThread(0xff);
1704 }
1705
1706
1707 /***********************************************************************
1708  *           GetAppCompatFlags16   (KERNEL.354)
1709  */
1710 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1711 {
1712     return GetAppCompatFlags( hTask );
1713 }
1714
1715
1716 /***********************************************************************
1717  *           GetAppCompatFlags   (USER32.206)
1718  */
1719 DWORD WINAPI GetAppCompatFlags( HTASK hTask )
1720 {
1721     TDB *pTask;
1722
1723     if (!hTask) hTask = GetCurrentTask();
1724     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1725     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1726     return pTask->compat_flags;
1727 }