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 "syslevel.h"
  35 #include "debugtools.h"
  36 #include "dosexe.h"
  37 #include "services.h"
  38 #include "server.h"
  39
  40 DEFAULT_DEBUG_CHANNEL(task)
  41 DECLARE_DEBUG_CHANNEL(relay)
  42 DECLARE_DEBUG_CHANNEL(toolhelp)
  43
  44   /* Min. number of thunks allocated when creating a new segment */
  45 #define MIN_THUNKS  32
  46
  47   /* Pointer to function to switch to a larger stack */
  48 int (*IF1632_CallLargeStack)( int (*func)(), void *arg ) = NULL;
  49
  50 static THHOOK DefaultThhook = { 0 };
  51 THHOOK *pThhook = &DefaultThhook;
  52
  53 #define hCurrentTask (pThhook->CurTDB)
  54 #define hFirstTask   (pThhook->HeadTDB)
  55 #define hLockedTask  (pThhook->LockTDB)
  56
  57 static UINT16 nTaskCount = 0;
  58
  59
  60 /***********************************************************************
  61  *           TASK_InstallTHHook
  62  */
  63 void TASK_InstallTHHook( THHOOK *pNewThhook )
  64 {
  65      THHOOK *pOldThhook = pThhook;
  66
  67      pThhook = pNewThhook? pNewThhook : &DefaultThhook;
  68
  69      *pThhook = *pOldThhook;
  70 }
  71
  72 /***********************************************************************
  73  *           TASK_GetNextTask
  74  */
  75 HTASK16 TASK_GetNextTask( HTASK16 hTask )
  76 {
  77     TDB* pTask = (TDB*)GlobalLock16(hTask);
  78
  79     if (pTask->hNext) return pTask->hNext;
  80     return (hFirstTask != hTask) ? hFirstTask : 0;
  81 }
  82
  83 /***********************************************************************
  84  *           TASK_LinkTask
  85  */
  86 static void TASK_LinkTask( HTASK16 hTask )
  87 {
  88     HTASK16 *prevTask;
  89     TDB *pTask;
  90
  91     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
  92     prevTask = &hFirstTask;
  93     while (*prevTask)
  94     {
  95         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
  96         if (prevTaskPtr->priority >= pTask->priority) break;
  97         prevTask = &prevTaskPtr->hNext;
  98     }
  99     pTask->hNext = *prevTask;
 100     *prevTask = hTask;
 101     nTaskCount++;
 102 }
 103
 104
 105 /***********************************************************************
 106  *           TASK_UnlinkTask
 107  */
 108 static void TASK_UnlinkTask( HTASK16 hTask )
 109 {
 110     HTASK16 *prevTask;
 111     TDB *pTask;
 112
 113     prevTask = &hFirstTask;
 114     while (*prevTask && (*prevTask != hTask))
 115     {
 116         pTask = (TDB *)GlobalLock16( *prevTask );
 117         prevTask = &pTask->hNext;
 118     }
 119     if (*prevTask)
 120     {
 121         pTask = (TDB *)GlobalLock16( *prevTask );
 122         *prevTask = pTask->hNext;
 123         pTask->hNext = 0;
 124         nTaskCount--;
 125     }
 126 }
 127
 128
 129 /***********************************************************************
 130  *           TASK_CreateThunks
 131  *
 132  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 133  * and containing 'count' entries.
 134  */
 135 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 136 {
 137     int i;
 138     WORD free;
 139     THUNKS *pThunk;
 140
 141     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 142     pThunk->next = 0;
 143     pThunk->magic = THUNK_MAGIC;
 144     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 145     free = pThunk->free;
 146     for (i = 0; i < count-1; i++)
 147     {
 148         free += 8;  /* Offset of next thunk */
 149         pThunk->thunks[4*i] = free;
 150     }
 151     pThunk->thunks[4*i] = 0;  /* Last thunk */
 152 }
 153
 154
 155 /***********************************************************************
 156  *           TASK_AllocThunk
 157  *
 158  * Allocate a thunk for MakeProcInstance().
 159  */
 160 static SEGPTR TASK_AllocThunk( HTASK16 hTask )
 161 {
 162     TDB *pTask;
 163     THUNKS *pThunk;
 164     WORD sel, base;
 165
 166     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 167     sel = pTask->hCSAlias;
 168     pThunk = &pTask->thunks;
 169     base = (int)pThunk - (int)pTask;
 170     while (!pThunk->free)
 171     {
 172         sel = pThunk->next;
 173         if (!sel)  /* Allocate a new segment */
 174         {
 175             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 176                                 pTask->hPDB, TRUE, FALSE, FALSE );
 177             if (!sel) return (SEGPTR)0;
 178             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 179             pThunk->next = sel;
 180         }
 181         pThunk = (THUNKS *)GlobalLock16( sel );
 182         base = 0;
 183     }
 184     base += pThunk->free;
 185     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 186     return PTR_SEG_OFF_TO_SEGPTR( sel, base );
 187 }
 188
 189
 190 /***********************************************************************
 191  *           TASK_FreeThunk
 192  *
 193  * Free a MakeProcInstance() thunk.
 194  */
 195 static BOOL TASK_FreeThunk( HTASK16 hTask, SEGPTR thunk )
 196 {
 197     TDB *pTask;
 198     THUNKS *pThunk;
 199     WORD sel, base;
 200
 201     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 202     sel = pTask->hCSAlias;
 203     pThunk = &pTask->thunks;
 204     base = (int)pThunk - (int)pTask;
 205     while (sel && (sel != HIWORD(thunk)))
 206     {
 207         sel = pThunk->next;
 208         pThunk = (THUNKS *)GlobalLock16( sel );
 209         base = 0;
 210     }
 211     if (!sel) return FALSE;
 212     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 213     pThunk->free = LOWORD(thunk) - base;
 214     return TRUE;
 215 }
 216
 217
 218 /***********************************************************************
 219  *           TASK_CallToStart
 220  *
 221  * 32-bit entry point for a new task. This function is responsible for
 222  * setting up the registers and jumping to the 16-bit entry point.
 223  */
 224 void TASK_CallToStart(void)
 225 {
 226     TDB *pTask = (TDB *)GlobalLock16( GetCurrentTask() );
 227     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 228     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 229     CONTEXT86 context;
 230
 231     /* Add task to 16-bit scheduler pool */
 232     TASK_Reschedule();
 233
 234     /* Registers at initialization must be:
 235      * ax   zero
 236      * bx   stack size in bytes
 237      * cx   heap size in bytes
 238      * si   previous app instance
 239      * di   current app instance
 240      * bp   zero
 241      * es   selector to the PSP
 242      * ds   dgroup of the application
 243      * ss   stack selector
 244      * sp   top of the stack
 245      */
 246
 247     memset( &context, 0, sizeof(context) );
 248     CS_reg(&context)  = GlobalHandleToSel16(pSegTable[pModule->cs - 1].hSeg);
 249     DS_reg(&context)  = GlobalHandleToSel16(pTask->hInstance);
 250     ES_reg(&context)  = pTask->hPDB;
 251     EIP_reg(&context) = pModule->ip;
 252     EBX_reg(&context) = pModule->stack_size;
 253     ECX_reg(&context) = pModule->heap_size;
 254     EDI_reg(&context) = pTask->hInstance;
 255     ESI_reg(&context) = pTask->hPrevInstance;
 256
 257     TRACE("Starting main program: cs:ip=%04lx:%04lx ds=%04lx ss:sp=%04x:%04x\n",
 258           CS_reg(&context), EIP_reg(&context), DS_reg(&context),
 259           SELECTOROF(pTask->teb->cur_stack),
 260           OFFSETOF(pTask->teb->cur_stack) );
 261
 262     Callbacks->CallRegisterShortProc( &context, 0 );
 263 }
 264
 265
 266 /***********************************************************************
 267  *           TASK_Create
 268  *
 269  * NOTE: This routine might be called by a Win32 thread. Thus, we need
 270  *       to be careful to protect global data structures. We do this
 271  *       by entering the Win16Lock while linking the task into the
 272  *       global task list.
 273  */
 274 BOOL TASK_Create( NE_MODULE *pModule, UINT16 cmdShow)
 275 {
 276     HTASK16 hTask;
 277     TDB *pTask;
 278     LPSTR cmd_line;
 279     char name[10];
 280     PDB *pdb32 = PROCESS_Current();
 281
 282       /* Allocate the task structure */
 283
 284     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 285                           pModule->self, FALSE, FALSE, FALSE );
 286     if (!hTask) return FALSE;
 287     pTask = (TDB *)GlobalLock16( hTask );
 288
 289     /* Fill the task structure */
 290
 291     pTask->nEvents       = 0;
 292     pTask->hSelf         = hTask;
 293     pTask->flags         = 0;
 294
 295     if (pModule->flags & NE_FFLAGS_WIN32)
 296         pTask->flags    |= TDBF_WIN32;
 297     if (pModule->lpDosTask)
 298         pTask->flags    |= TDBF_WINOLDAP;
 299
 300     pTask->hInstance     = pModule->self;
 301     pTask->hPrevInstance = 0;
 302     /* NOTE: for 16-bit tasks, the instance handles are updated later on
 303              in NE_InitProcess */
 304
 305     pTask->version       = pModule->expected_version;
 306     pTask->hModule       = pModule->self;
 307     pTask->hParent       = GetCurrentTask();
 308     pTask->magic         = TDB_MAGIC;
 309     pTask->nCmdShow      = cmdShow;
 310     pTask->teb           = NtCurrentTeb();
 311     pTask->curdrive      = DRIVE_GetCurrentDrive() | 0x80;
 312     strcpy( pTask->curdir, "\\" );
 313     lstrcpynA( pTask->curdir + 1, DRIVE_GetDosCwd( DRIVE_GetCurrentDrive() ),
 314                  sizeof(pTask->curdir) - 1 );
 315
 316       /* Create the thunks block */
 317
 318     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 319
 320       /* Copy the module name */
 321
 322     GetModuleName16( pModule->self, name, sizeof(name) );
 323     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 324
 325       /* Allocate a selector for the PDB */
 326
 327     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB16),
 328                                     pModule->self, FALSE, FALSE, FALSE, NULL );
 329
 330       /* Fill the PDB */
 331
 332     pTask->pdb.int20 = 0x20cd;
 333     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 334     PUT_DWORD(&pTask->pdb.dispatcher[1], (DWORD)NE_GetEntryPoint(
 335            GetModuleHandle16("KERNEL"), 102 ));  /* KERNEL.102 is DOS3Call() */
 336     pTask->pdb.savedint22 = INT_GetPMHandler( 0x22 );
 337     pTask->pdb.savedint23 = INT_GetPMHandler( 0x23 );
 338     pTask->pdb.savedint24 = INT_GetPMHandler( 0x24 );
 339     pTask->pdb.fileHandlesPtr =
 340         PTR_SEG_OFF_TO_SEGPTR( GlobalHandleToSel16(pTask->hPDB),
 341                                (int)&((PDB16 *)0)->fileHandles );
 342     pTask->pdb.hFileHandles = 0;
 343     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 344     pTask->pdb.environment    = pdb32->env_db->env_sel;
 345     pTask->pdb.nbFiles        = 20;
 346
 347     /* Fill the command line */
 348
 349     cmd_line = pdb32->env_db->cmd_line;
 350     while (*cmd_line && (*cmd_line != ' ') && (*cmd_line != '\t')) cmd_line++;
 351     while ((*cmd_line == ' ') || (*cmd_line == '\t')) cmd_line++;
 352     lstrcpynA( pTask->pdb.cmdLine+1, cmd_line, sizeof(pTask->pdb.cmdLine)-1);
 353     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 354
 355       /* Get the compatibility flags */
 356
 357     pTask->compat_flags = GetProfileIntA( "Compatibility", name, 0 );
 358
 359       /* Allocate a code segment alias for the TDB */
 360
 361     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 362                                           sizeof(TDB), pTask->hPDB, TRUE,
 363                                           FALSE, FALSE, NULL );
 364
 365       /* Set the owner of the environment block */
 366
 367     FarSetOwner16( pTask->pdb.environment, pTask->hPDB );
 368
 369       /* Default DTA overwrites command-line */
 370
 371     pTask->dta = PTR_SEG_OFF_TO_SEGPTR( pTask->hPDB,
 372                                 (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 373
 374     /* Create scheduler event for 16-bit tasks */
 375
 376     if ( !(pTask->flags & TDBF_WIN32) )
 377     {
 378         pTask->hEvent = CreateEventA( NULL, TRUE, FALSE, NULL );
 379         pTask->hEvent = ConvertToGlobalHandle( pTask->hEvent );
 380     }
 381
 382     /* Enter task handle into thread and process */
 383
 384     pTask->teb->htask16 = pTask->teb->process->task = hTask;
 385     TRACE("module='%s' cmdline='%s' task=%04x\n", name, cmd_line, hTask );
 386
 387     /* Add the task to the linked list */
 388
 389     SYSLEVEL_EnterWin16Lock();
 390     TASK_LinkTask( hTask );
 391     SYSLEVEL_LeaveWin16Lock();
 392
 393     return TRUE;
 394 }
 395
 396 /***********************************************************************
 397  *           TASK_DeleteTask
 398  */
 399 static void TASK_DeleteTask( HTASK16 hTask )
 400 {
 401     TDB *pTask;
 402     HGLOBAL16 hPDB;
 403
 404     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 405     hPDB = pTask->hPDB;
 406
 407     pTask->magic = 0xdead; /* invalidate signature */
 408
 409     /* Delete the Win32 part of the task */
 410
 411 /*    PROCESS_FreePDB( pTask->teb->process ); FIXME */
 412 /*    K32OBJ_DecCount( &pTask->teb->header ); FIXME */
 413
 414     /* Free the selector aliases */
 415
 416     GLOBAL_FreeBlock( pTask->hCSAlias );
 417     GLOBAL_FreeBlock( pTask->hPDB );
 418
 419     /* Free the task module */
 420
 421     FreeModule16( pTask->hModule );
 422
 423     /* Free the task structure itself */
 424
 425     GlobalFree16( hTask );
 426
 427     /* Free all memory used by this task (including the 32-bit stack, */
 428     /* the environment block and the thunk segments). */
 429
 430     GlobalFreeAll16( hPDB );
 431 }
 432
 433 /***********************************************************************
 434  *           TASK_KillTask
 435  */
 436 void TASK_KillTask( HTASK16 hTask )
 437 {
 438     TDB *pTask;
 439
 440     /* Enter the Win16Lock to protect global data structures */
 441     SYSLEVEL_EnterWin16Lock();
 442
 443     if ( !hTask ) hTask = GetCurrentTask();
 444     pTask = (TDB *)GlobalLock16( hTask );
 445     if ( !pTask )
 446     {
 447         SYSLEVEL_LeaveWin16Lock();
 448         return;
 449     }
 450
 451     TRACE("Killing task %04x\n", hTask );
 452
 453 #ifdef MZ_SUPPORTED
 454 {
 455     /* Kill DOS VM task */
 456     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 457     if ( pModule->lpDosTask )
 458         MZ_KillModule( pModule->lpDosTask );
 459 }
 460 #endif
 461
 462     /* Perform USER cleanup */
 463
 464     TASK_CallTaskSignalProc( USIG16_TERMINATION, hTask );
 465     PROCESS_CallUserSignalProc( USIG_PROCESS_EXIT, 0, 0 );
 466     PROCESS_CallUserSignalProc( USIG_THREAD_EXIT, GetCurrentThreadId(), 0 );
 467     PROCESS_CallUserSignalProc( USIG_PROCESS_DESTROY, 0, 0 );
 468
 469     if (nTaskCount <= 1)
 470     {
 471         TRACE("this is the last task, exiting\n" );
 472         ExitKernel16();
 473     }
 474
 475     /* FIXME: Hack! Send a message to the initial task so that
 476      * the GetMessage wakes up and the initial task can check whether
 477      * it is the only remaining one and terminate itself ...
 478      * The initial task should probably install hooks or something
 479      * to get informed about task termination :-/
 480      */
 481     Callout.PostAppMessage16( PROCESS_Initial()->task, WM_NULL, 0, 0 );
 482
 483     /* Remove the task from the list to be sure we never switch back to it */
 484     TASK_UnlinkTask( hTask );
 485     if( nTaskCount )
 486     {
 487         TDB* p = (TDB *)GlobalLock16( hFirstTask );
 488         while( p )
 489         {
 490             if( p->hYieldTo == hTask ) p->hYieldTo = 0;
 491             p = (TDB *)GlobalLock16( p->hNext );
 492         }
 493     }
 494
 495     pTask->nEvents = 0;
 496
 497     if ( hLockedTask == hTask )
 498         hLockedTask = 0;
 499
 500     TASK_DeleteTask( hTask );
 501
 502     /* When deleting the current task ... */
 503     if ( hTask == hCurrentTask )
 504     {
 505         DWORD lockCount;
 506
 507         /* ... schedule another one ... */
 508         TASK_Reschedule();
 509
 510         /* ... and completely release the Win16Lock, just in case. */
 511         ReleaseThunkLock( &lockCount );
 512
 513         return;
 514     }
 515
 516     SYSLEVEL_LeaveWin16Lock();
 517 }
 518
 519 /***********************************************************************
 520  *           TASK_Reschedule
 521  *
 522  * This is where all the magic of task-switching happens!
 523  *
 524  * 16-bit Windows performs non-preemptive (cooperative) multitasking.
 525  * This means that each 16-bit task runs until it voluntarily yields
 526  * control, at which point the scheduler gets active and selects the
 527  * next task to run.
 528  *
 529  * In Wine, all processes, even 16-bit ones, are scheduled preemptively
 530  * by the standard scheduler of the underlying OS.  As many 16-bit apps
 531  * *rely* on the behaviour of the Windows scheduler, however, we have
 532  * to simulate that behaviour.
 533  *
 534  * This is achieved as follows: every 16-bit task is at time (except
 535  * during task creation and deletion) in one of two states: either it
 536  * is the one currently running, then the global variable hCurrentTask
 537  * contains its task handle, or it is not currently running, then it
 538  * is blocked on a special scheduler event, a global handle to which
 539  * is stored in the task struct.
 540  *
 541  * When the current task yields control, this routine gets called. Its
 542  * purpose is to determine the next task to be active, signal the
 543  * scheduler event of that task, and then put the current task to sleep
 544  * waiting for *its* scheduler event to get signalled again.
 545  *
 546  * This routine can get called in a few other special situations as well:
 547  *
 548  * - On creation of a 16-bit task, the Unix process executing the task
 549  *   calls TASK_Reschedule once it has completed its initialization.
 550  *   At this point, the task needs to be blocked until its scheduler
 551  *   event is signalled the first time (this will be done by the parent
 552  *   process to get the task up and running).
 553  *
 554  * - When the task currently running terminates itself, this routine gets
 555  *   called and has to schedule another task, *without* blocking the
 556  *   terminating task.
 557  *
 558  * - When a 32-bit thread posts an event for a 16-bit task, it might be
 559  *   the case that *no* 16-bit task is currently running.  In this case
 560  *   the task that has now an event pending is to be scheduled.
 561  *
 562  */
 563 void TASK_Reschedule(void)
 564 {
 565     TDB *pOldTask = NULL, *pNewTask = NULL;
 566     HTASK16 hOldTask = 0, hNewTask = 0;
 567     enum { MODE_YIELD, MODE_SLEEP, MODE_WAKEUP } mode;
 568     DWORD lockCount;
 569
 570     SYSLEVEL_EnterWin16Lock();
 571
 572     /* Check what we need to do */
 573     hOldTask = GetCurrentTask();
 574     pOldTask = (TDB *)GlobalLock16( hOldTask );
 575     TRACE( "entered with hCurrentTask %04x by hTask %04x (pid %ld)\n",
 576            hCurrentTask, hOldTask, (long) getpid() );
 577
 578     if ( pOldTask && THREAD_IsWin16( NtCurrentTeb() ) )
 579     {
 580         /* We are called by an active (non-deleted) 16-bit task */
 581
 582         /* If we don't even have a current task, or else the current
 583            task has yielded, we'll need to schedule a new task and
 584            (possibly) put the calling task to sleep.  Otherwise, we
 585            only block the caller. */
 586
 587         if ( !hCurrentTask || hCurrentTask == hOldTask )
 588             mode = MODE_YIELD;
 589         else
 590             mode = MODE_SLEEP;
 591     }
 592     else
 593     {
 594         /* We are called by a deleted 16-bit task or a 32-bit thread */
 595
 596         /* The only situation where we need to do something is if we
 597            now do not have a current task.  Then, we'll need to wake up
 598            some task that has events pending. */
 599
 600         if ( !hCurrentTask || hCurrentTask == hOldTask )
 601             mode = MODE_WAKEUP;
 602         else
 603         {
 604             /* nothing to do */
 605             SYSLEVEL_LeaveWin16Lock();
 606             return;
 607         }
 608     }
 609
 610     /* Find a task to yield to: check for DirectedYield() */
 611     if ( mode == MODE_YIELD && pOldTask && pOldTask->hYieldTo )
 612     {
 613         hNewTask = pOldTask->hYieldTo;
 614         pNewTask = (TDB *)GlobalLock16( hNewTask );
 615         if( !pNewTask || !pNewTask->nEvents) hNewTask = 0;
 616         pOldTask->hYieldTo = 0;
 617     }
 618
 619     /* Find a task to yield to: check for pending events */
 620     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && !hNewTask )
 621     {
 622         hNewTask = hFirstTask;
 623         while (hNewTask)
 624         {
 625             pNewTask = (TDB *)GlobalLock16( hNewTask );
 626
 627             TRACE( "\ttask = %04x, events = %i\n", hNewTask, pNewTask->nEvents );
 628
 629             if (pNewTask->nEvents) break;
 630             hNewTask = pNewTask->hNext;
 631         }
 632         if (hLockedTask && (hNewTask != hLockedTask)) hNewTask = 0;
 633     }
 634
 635     /* If we are still the task with highest priority, just return ... */
 636     if ( mode == MODE_YIELD && hNewTask == hCurrentTask )
 637     {
 638         TRACE("returning to the current task (%04x)\n", hCurrentTask );
 639         SYSLEVEL_LeaveWin16Lock();
 640
 641         /* Allow Win32 threads to thunk down even while a Win16 task is
 642            in a tight PeekMessage() or Yield() loop ... */
 643         ReleaseThunkLock( &lockCount );
 644         RestoreThunkLock( lockCount );
 645         return;
 646     }
 647
 648     /* If no task to yield to found, suspend 16-bit scheduler ... */
 649     if ( mode == MODE_YIELD && !hNewTask )
 650     {
 651         TRACE("No currently active task\n");
 652         hCurrentTask = 0;
 653     }
 654
 655     /* If we found a task to wake up, do it ... */
 656     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && hNewTask )
 657     {
 658         TRACE("Switching to task %04x (%.8s)\n",
 659                       hNewTask, pNewTask->module_name );
 660
 661         pNewTask->priority++;
 662         TASK_UnlinkTask( hNewTask );
 663         TASK_LinkTask( hNewTask );
 664         pNewTask->priority--;
 665
 666         hCurrentTask = hNewTask;
 667         SetEvent( pNewTask->hEvent );
 668
 669         /* This is set just in case some app reads it ... */
 670         pNewTask->ss_sp = pNewTask->teb->cur_stack;
 671     }
 672
 673     /* If we need to put the current task to sleep, do it ... */
 674     if ( (mode == MODE_YIELD || mode == MODE_SLEEP) && hOldTask != hCurrentTask )
 675     {
 676         ResetEvent( pOldTask->hEvent );
 677
 678         ReleaseThunkLock( &lockCount );
 679         SYSLEVEL_CheckNotLevel( 1 );
 680         WaitForSingleObject( pOldTask->hEvent, INFINITE );
 681         RestoreThunkLock( lockCount );
 682     }
 683
 684     SYSLEVEL_LeaveWin16Lock();
 685 }
 686
 687 /***********************************************************************
 688  *           InitTask  (KERNEL.91)
 689  *
 690  * Called by the application startup code.
 691  */
 692 void WINAPI InitTask16( CONTEXT86 *context )
 693 {
 694     TDB *pTask;
 695     INSTANCEDATA *pinstance;
 696     SEGPTR ptr;
 697
 698     EAX_reg(context) = 0;
 699     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
 700
 701     /* Note: we need to trust that BX/CX contain the stack/heap sizes,
 702        as some apps, notably Visual Basic apps, *modify* the heap/stack
 703        size of the instance data segment before calling InitTask() */
 704
 705     /* Initialize the INSTANCEDATA structure */
 706     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 707     pinstance->stackmin    = OFFSETOF( pTask->teb->cur_stack );
 708     pinstance->stackbottom = pinstance->stackmin; /* yup, that's right. Confused me too. */
 709     pinstance->stacktop    = ( pinstance->stackmin > BX_reg(context)?
 710                                pinstance->stackmin - BX_reg(context) : 0 ) + 150;
 711
 712     /* Initialize the local heap */
 713     if ( CX_reg(context) )
 714         LocalInit16( pTask->hInstance, 0, CX_reg(context) );
 715
 716     /* Initialize implicitly loaded DLLs */
 717     NE_InitializeDLLs( pTask->hModule );
 718     NE_DllProcessAttach( pTask->hModule );
 719
 720     /* Registers on return are:
 721      * ax     1 if OK, 0 on error
 722      * cx     stack limit in bytes
 723      * dx     cmdShow parameter
 724      * si     instance handle of the previous instance
 725      * di     instance handle of the new task
 726      * es:bx  pointer to command-line inside PSP
 727      *
 728      * 0 (=%bp) is pushed on the stack
 729      */
 730     ptr = stack16_push( sizeof(WORD) );
 731     *(WORD *)PTR_SEG_TO_LIN(ptr) = 0;
 732     ESP_reg(context) -= 2;
 733
 734     EAX_reg(context) = 1;
 735
 736     if (!pTask->pdb.cmdLine[0]) EBX_reg(context) = 0x80;
 737     else
 738     {
 739         LPBYTE p = &pTask->pdb.cmdLine[1];
 740         while ((*p == ' ') || (*p == '\t')) p++;
 741         EBX_reg(context) = 0x80 + (p - pTask->pdb.cmdLine);
 742     }
 743     ECX_reg(context) = pinstance->stacktop;
 744     EDX_reg(context) = pTask->nCmdShow;
 745     ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 746     EDI_reg(context) = (DWORD)pTask->hInstance;
 747     ES_reg (context) = (WORD)pTask->hPDB;
 748 }
 749
 750
 751 /***********************************************************************
 752  *           WaitEvent  (KERNEL.30)
 753  */
 754 BOOL16 WINAPI WaitEvent16( HTASK16 hTask )
 755 {
 756     TDB *pTask;
 757
 758     if (!hTask) hTask = GetCurrentTask();
 759     pTask = (TDB *)GlobalLock16( hTask );
 760
 761     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 762     {
 763         FIXME("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 764         return TRUE;
 765     }
 766
 767     if (pTask->nEvents > 0)
 768     {
 769         pTask->nEvents--;
 770         return FALSE;
 771     }
 772     TASK_Reschedule();
 773
 774     /* When we get back here, we have an event */
 775
 776     if (pTask->nEvents > 0) pTask->nEvents--;
 777     return TRUE;
 778 }
 779
 780
 781 /***********************************************************************
 782  *           PostEvent  (KERNEL.31)
 783  */
 784 void WINAPI PostEvent16( HTASK16 hTask )
 785 {
 786     TDB *pTask;
 787
 788     if (!hTask) hTask = GetCurrentTask();
 789     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 790
 791     if ( !THREAD_IsWin16( pTask->teb ) )
 792     {
 793         FIXME("called for Win32 thread (%04x)!\n", pTask->teb->teb_sel );
 794         return;
 795     }
 796
 797     pTask->nEvents++;
 798
 799     /* If we are a 32-bit task, we might need to wake up the 16-bit scheduler */
 800     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 801         TASK_Reschedule();
 802 }
 803
 804
 805 /***********************************************************************
 806  *           SetPriority  (KERNEL.32)
 807  */
 808 void WINAPI SetPriority16( HTASK16 hTask, INT16 delta )
 809 {
 810     TDB *pTask;
 811     INT16 newpriority;
 812
 813     if (!hTask) hTask = GetCurrentTask();
 814     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 815     newpriority = pTask->priority + delta;
 816     if (newpriority < -32) newpriority = -32;
 817     else if (newpriority > 15) newpriority = 15;
 818
 819     pTask->priority = newpriority + 1;
 820     TASK_UnlinkTask( hTask );
 821     TASK_LinkTask( hTask );
 822     pTask->priority--;
 823 }
 824
 825
 826 /***********************************************************************
 827  *           LockCurrentTask  (KERNEL.33)
 828  */
 829 HTASK16 WINAPI LockCurrentTask16( BOOL16 bLock )
 830 {
 831     if (bLock) hLockedTask = GetCurrentTask();
 832     else hLockedTask = 0;
 833     return hLockedTask;
 834 }
 835
 836
 837 /***********************************************************************
 838  *           IsTaskLocked  (KERNEL.122)
 839  */
 840 HTASK16 WINAPI IsTaskLocked16(void)
 841 {
 842     return hLockedTask;
 843 }
 844
 845
 846 /***********************************************************************
 847  *           OldYield  (KERNEL.117)
 848  */
 849 void WINAPI OldYield16(void)
 850 {
 851     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 852
 853     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 854     {
 855         FIXME("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 856         return;
 857     }
 858
 859     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 860     TASK_Reschedule();
 861     if (pCurTask) pCurTask->nEvents--;
 862 }
 863
 864 /***********************************************************************
 865  *           WIN32_OldYield16  (KERNEL.447)
 866  */
 867 void WINAPI WIN32_OldYield16(void)
 868 {
 869    DWORD count;
 870
 871    ReleaseThunkLock(&count);
 872    RestoreThunkLock(count);
 873 }
 874
 875 /***********************************************************************
 876  *           DirectedYield  (KERNEL.150)
 877  */
 878 void WINAPI DirectedYield16( HTASK16 hTask )
 879 {
 880     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 881
 882     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 883     {
 884         FIXME("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 885         return;
 886     }
 887
 888     TRACE("%04x: DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 889
 890     pCurTask->hYieldTo = hTask;
 891     OldYield16();
 892
 893     TRACE("%04x: back from DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 894 }
 895
 896 /***********************************************************************
 897  *           Yield16  (KERNEL.29)
 898  */
 899 void WINAPI Yield16(void)
 900 {
 901     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 902
 903     if (pCurTask) pCurTask->hYieldTo = 0;
 904     if (pCurTask && pCurTask->hQueue) Callout.UserYield16();
 905     else OldYield16();
 906 }
 907
 908 /***********************************************************************
 909  *           KERNEL_490  (KERNEL.490)
 910  */
 911 HTASK16 WINAPI KERNEL_490( HTASK16 someTask )
 912 {
 913     if ( !someTask ) return 0;
 914
 915     FIXME("(%04x): stub\n", someTask );
 916     return 0;
 917 }
 918
 919 /***********************************************************************
 920  *           MakeProcInstance16  (KERNEL.51)
 921  */
 922 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 923 {
 924     BYTE *thunk,*lfunc;
 925     SEGPTR thunkaddr;
 926
 927     if (!func) {
 928       ERR("Ouch ! MakeProcInstance called with func == NULL !\n");
 929       return (FARPROC16)0; /* Windows seems to do the same */
 930     }
 931     if ( GetTaskDS16() !=hInstance )
 932     {
 933         ERR("Problem with hInstance? Got %04x, using %04x instead\n",
 934                    hInstance,GetTaskDS16());
 935         hInstance = GetTaskDS16();
 936     }
 937     if (!hInstance) hInstance = CURRENT_DS;
 938     thunkaddr = TASK_AllocThunk( GetCurrentTask() );
 939     if (!thunkaddr) return (FARPROC16)0;
 940     thunk = PTR_SEG_TO_LIN( thunkaddr );
 941     lfunc = PTR_SEG_TO_LIN( func );
 942
 943     TRACE("(%08lx,%04x): got thunk %08lx\n",
 944           (DWORD)func, hInstance, (DWORD)thunkaddr );
 945     if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) ||
 946         ((lfunc[0]==0x1e) && (lfunc[1]==0x58))
 947     ) {
 948         FIXME("thunk would be useless for %p, overwriting with nop;nop;\n", func );
 949         lfunc[0]=0x90; /* nop */
 950         lfunc[1]=0x90; /* nop */
 951     }
 952
 953     *thunk++ = 0xb8;    /* movw instance, %ax */
 954     *thunk++ = (BYTE)(hInstance & 0xff);
 955     *thunk++ = (BYTE)(hInstance >> 8);
 956     *thunk++ = 0xea;    /* ljmp func */
 957     *(DWORD *)thunk = (DWORD)func;
 958     return (FARPROC16)thunkaddr;
 959 }
 960
 961
 962 /***********************************************************************
 963  *           FreeProcInstance16  (KERNEL.52)
 964  */
 965 void WINAPI FreeProcInstance16( FARPROC16 func )
 966 {
 967     TRACE("(%08lx)\n", (DWORD)func );
 968     TASK_FreeThunk( GetCurrentTask(), (SEGPTR)func );
 969 }
 970
 971 /**********************************************************************
 972  *          TASK_GetCodeSegment
 973  *
 974  * Helper function for GetCodeHandle/GetCodeInfo: Retrieve the module
 975  * and logical segment number of a given code segment.
 976  *
 977  * 'proc' either *is* already a pair of module handle and segment number,
 978  * in which case there's nothing to do.  Otherwise, it is a pointer to
 979  * a function, and we need to retrieve the code segment.  If the pointer
 980  * happens to point to a thunk, we'll retrieve info about the code segment
 981  * where the function pointed to by the thunk resides, not the thunk itself.
 982  *
 983  * FIXME: if 'proc' is a SNOOP16 return stub, we should retrieve info about
 984  *        the function the snoop code will return to ...
 985  *
 986  */
 987 static BOOL TASK_GetCodeSegment( FARPROC16 proc, NE_MODULE **ppModule,
 988                                  SEGTABLEENTRY **ppSeg, int *pSegNr )
 989 {
 990     NE_MODULE *pModule = NULL;
 991     SEGTABLEENTRY *pSeg = NULL;
 992     int segNr;
 993
 994     /* Try pair of module handle / segment number */
 995     pModule = (NE_MODULE *) GlobalLock16( HIWORD( proc ) );
 996     if ( pModule && pModule->magic == IMAGE_OS2_SIGNATURE )
 997     {
 998         segNr = LOWORD( proc );
 999         if ( segNr && segNr <= pModule->seg_count )
1000             pSeg = NE_SEG_TABLE( pModule ) + segNr-1;
1001     }
1002
1003     /* Try thunk or function */
1004     else
1005     {
1006         BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
1007         WORD selector;
1008
1009         if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1010             selector = thunk[6] + (thunk[7] << 8);
1011         else
1012             selector = HIWORD( proc );
1013
1014         pModule = NE_GetPtr( GlobalHandle16( selector ) );
1015         pSeg = pModule? NE_SEG_TABLE( pModule ) : NULL;
1016
1017         if ( pModule )
1018             for ( segNr = 1; segNr <= pModule->seg_count; segNr++, pSeg++ )
1019                 if ( GlobalHandleToSel16(pSeg->hSeg) == selector )
1020                     break;
1021
1022         if ( pModule && segNr > pModule->seg_count )
1023             pSeg = NULL;
1024     }
1025
1026     /* Abort if segment not found */
1027
1028     if ( !pModule || !pSeg )
1029         return FALSE;
1030
1031     /* Return segment data */
1032
1033     if ( ppModule ) *ppModule = pModule;
1034     if ( ppSeg    ) *ppSeg    = pSeg;
1035     if ( pSegNr   ) *pSegNr   = segNr;
1036
1037     return TRUE;
1038 }
1039
1040 /**********************************************************************
1041  *          GetCodeHandle    (KERNEL.93)
1042  */
1043 HANDLE16 WINAPI GetCodeHandle16( FARPROC16 proc )
1044 {
1045     SEGTABLEENTRY *pSeg;
1046
1047     if ( !TASK_GetCodeSegment( proc, NULL, &pSeg, NULL ) )
1048         return (HANDLE16)0;
1049
1050     return pSeg->hSeg;
1051 }
1052
1053 /**********************************************************************
1054  *          GetCodeInfo    (KERNEL.104)
1055  */
1056 BOOL16 WINAPI GetCodeInfo16( FARPROC16 proc, SEGINFO *segInfo )
1057 {
1058     NE_MODULE *pModule;
1059     SEGTABLEENTRY *pSeg;
1060     int segNr;
1061
1062     if ( !TASK_GetCodeSegment( proc, &pModule, &pSeg, &segNr ) )
1063         return FALSE;
1064
1065     /* Fill in segment information */
1066
1067     segInfo->offSegment = pSeg->filepos;
1068     segInfo->cbSegment  = pSeg->size;
1069     segInfo->flags      = pSeg->flags;
1070     segInfo->cbAlloc    = pSeg->minsize;
1071     segInfo->h          = pSeg->hSeg;
1072     segInfo->alignShift = pModule->alignment;
1073
1074     if ( segNr == pModule->dgroup )
1075         segInfo->cbAlloc += pModule->heap_size + pModule->stack_size;
1076
1077     /* Return module handle in %es */
1078
1079     CURRENT_STACK16->es = GlobalHandleToSel16( pModule->self );
1080
1081     return TRUE;
1082 }
1083
1084
1085 /**********************************************************************
1086  *          DefineHandleTable16    (KERNEL.94)
1087  */
1088 BOOL16 WINAPI DefineHandleTable16( WORD wOffset )
1089 {
1090     return TRUE;  /* FIXME */
1091 }
1092
1093
1094 /***********************************************************************
1095  *           SetTaskQueue  (KERNEL.34)
1096  */
1097 HQUEUE16 WINAPI SetTaskQueue16( HTASK16 hTask, HQUEUE16 hQueue )
1098 {
1099     HQUEUE16 hPrev;
1100     TDB *pTask;
1101
1102     if (!hTask) hTask = GetCurrentTask();
1103     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1104
1105     hPrev = pTask->hQueue;
1106     pTask->hQueue = hQueue;
1107
1108     return hPrev;
1109 }
1110
1111
1112 /***********************************************************************
1113  *           GetTaskQueue  (KERNEL.35)
1114  */
1115 HQUEUE16 WINAPI GetTaskQueue16( HTASK16 hTask )
1116 {
1117     TDB *pTask;
1118
1119     if (!hTask) hTask = GetCurrentTask();
1120     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1121     return pTask->hQueue;
1122 }
1123
1124 /***********************************************************************
1125  *           SetThreadQueue  (KERNEL.463)
1126  */
1127 HQUEUE16 WINAPI SetThreadQueue16( DWORD thread, HQUEUE16 hQueue )
1128 {
1129     TEB *teb = thread? THREAD_IdToTEB( thread ) : NtCurrentTeb();
1130     HQUEUE16 oldQueue = teb? teb->queue : 0;
1131
1132     if ( teb )
1133     {
1134         teb->queue = hQueue;
1135
1136         if ( GetTaskQueue16( teb->process->task ) == oldQueue )
1137             SetTaskQueue16( teb->process->task, hQueue );
1138     }
1139
1140     return oldQueue;
1141 }
1142
1143 /***********************************************************************
1144  *           GetThreadQueue  (KERNEL.464)
1145  */
1146 HQUEUE16 WINAPI GetThreadQueue16( DWORD thread )
1147 {
1148     TEB *teb = NULL;
1149     if ( !thread )
1150         teb = NtCurrentTeb();
1151     else if ( HIWORD(thread) )
1152         teb = THREAD_IdToTEB( thread );
1153     else if ( IsTask16( (HTASK16)thread ) )
1154         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1155
1156     return (HQUEUE16)(teb? teb->queue : 0);
1157 }
1158
1159 /***********************************************************************
1160  *           SetFastQueue  (KERNEL.624)
1161  */
1162 VOID WINAPI SetFastQueue16( DWORD thread, HANDLE hQueue )
1163 {
1164     TEB *teb = NULL;
1165     if ( !thread )
1166         teb = NtCurrentTeb();
1167     else if ( HIWORD(thread) )
1168         teb = THREAD_IdToTEB( thread );
1169     else if ( IsTask16( (HTASK16)thread ) )
1170         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1171
1172     if ( teb ) teb->queue = (HQUEUE16) hQueue;
1173 }
1174
1175 /***********************************************************************
1176  *           GetFastQueue  (KERNEL.625)
1177  */
1178 HANDLE WINAPI GetFastQueue16( void )
1179 {
1180     TEB *teb = NtCurrentTeb();
1181     if (!teb) return 0;
1182
1183     if (!teb->queue)
1184         Callout.InitThreadInput16( 0, THREAD_IsWin16(teb)? 4 : 5 );
1185
1186     if (!teb->queue)
1187         FIXME("(): should initialize thread-local queue, expect failure!\n" );
1188
1189     return (HANDLE)teb->queue;
1190 }
1191
1192 /***********************************************************************
1193  *           SwitchStackTo   (KERNEL.108)
1194  */
1195 void WINAPI SwitchStackTo16( WORD seg, WORD ptr, WORD top )
1196 {
1197     TDB *pTask;
1198     STACK16FRAME *oldFrame, *newFrame;
1199     INSTANCEDATA *pData;
1200     UINT16 copySize;
1201
1202     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1203     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
1204     TRACE("old=%04x:%04x new=%04x:%04x\n",
1205           SELECTOROF( pTask->teb->cur_stack ),
1206           OFFSETOF( pTask->teb->cur_stack ), seg, ptr );
1207
1208     /* Save the old stack */
1209
1210     oldFrame = THREAD_STACK16( pTask->teb );
1211     /* pop frame + args and push bp */
1212     pData->old_ss_sp   = pTask->teb->cur_stack + sizeof(STACK16FRAME)
1213                            + 2 * sizeof(WORD);
1214     *(WORD *)PTR_SEG_TO_LIN(pData->old_ss_sp) = oldFrame->bp;
1215     pData->stacktop    = top;
1216     pData->stackmin    = ptr;
1217     pData->stackbottom = ptr;
1218
1219     /* Switch to the new stack */
1220
1221     /* Note: we need to take the 3 arguments into account; otherwise,
1222      * the stack will underflow upon return from this function.
1223      */
1224     copySize = oldFrame->bp - OFFSETOF(pData->old_ss_sp);
1225     copySize += 3 * sizeof(WORD) + sizeof(STACK16FRAME);
1226     pTask->teb->cur_stack = PTR_SEG_OFF_TO_SEGPTR( seg, ptr - copySize );
1227     newFrame = THREAD_STACK16( pTask->teb );
1228
1229     /* Copy the stack frame and the local variables to the new stack */
1230
1231     memmove( newFrame, oldFrame, copySize );
1232     newFrame->bp = ptr;
1233     *(WORD *)PTR_SEG_OFF_TO_LIN( seg, ptr ) = 0;  /* clear previous bp */
1234 }
1235
1236
1237 /***********************************************************************
1238  *           SwitchStackBack   (KERNEL.109)
1239  */
1240 void WINAPI SwitchStackBack16( CONTEXT86 *context )
1241 {
1242     STACK16FRAME *oldFrame, *newFrame;
1243     INSTANCEDATA *pData;
1244
1245     if (!(pData = (INSTANCEDATA *)GlobalLock16(SELECTOROF(NtCurrentTeb()->cur_stack))))
1246         return;
1247     if (!pData->old_ss_sp)
1248     {
1249         WARN("No previous SwitchStackTo\n" );
1250         return;
1251     }
1252     TRACE("restoring stack %04x:%04x\n",
1253           SELECTOROF(pData->old_ss_sp), OFFSETOF(pData->old_ss_sp) );
1254
1255     oldFrame = CURRENT_STACK16;
1256
1257     /* Pop bp from the previous stack */
1258
1259     BP_reg(context) = *(WORD *)PTR_SEG_TO_LIN(pData->old_ss_sp);
1260     pData->old_ss_sp += sizeof(WORD);
1261
1262     /* Switch back to the old stack */
1263
1264     NtCurrentTeb()->cur_stack = pData->old_ss_sp - sizeof(STACK16FRAME);
1265     SS_reg(context)  = SELECTOROF(pData->old_ss_sp);
1266     ESP_reg(context) = OFFSETOF(pData->old_ss_sp) - sizeof(DWORD); /*ret addr*/
1267     pData->old_ss_sp = 0;
1268
1269     /* Build a stack frame for the return */
1270
1271     newFrame = CURRENT_STACK16;
1272     newFrame->frame32     = oldFrame->frame32;
1273     newFrame->module_cs   = oldFrame->module_cs;
1274     newFrame->callfrom_ip = oldFrame->callfrom_ip;
1275     newFrame->entry_ip    = oldFrame->entry_ip;
1276 }
1277
1278
1279 /***********************************************************************
1280  *           GetTaskQueueDS16  (KERNEL.118)
1281  */
1282 void WINAPI GetTaskQueueDS16(void)
1283 {
1284     CURRENT_STACK16->ds = GlobalHandleToSel16( GetTaskQueue16(0) );
1285 }
1286
1287
1288 /***********************************************************************
1289  *           GetTaskQueueES16  (KERNEL.119)
1290  */
1291 void WINAPI GetTaskQueueES16(void)
1292 {
1293     CURRENT_STACK16->es = GlobalHandleToSel16( GetTaskQueue16(0) );
1294 }
1295
1296
1297 /***********************************************************************
1298  *           GetCurrentTask   (KERNEL.36)
1299  */
1300 HTASK16 WINAPI GetCurrentTask(void)
1301 {
1302     return PROCESS_Current()->task;
1303 }
1304
1305 DWORD WINAPI WIN16_GetCurrentTask(void)
1306 {
1307     /* This is the version used by relay code; the first task is */
1308     /* returned in the high word of the result */
1309     return MAKELONG( GetCurrentTask(), hFirstTask );
1310 }
1311
1312
1313 /***********************************************************************
1314  *           GetCurrentPDB   (KERNEL.37)
1315  *
1316  * UNDOC: returns PSP of KERNEL in high word
1317  */
1318 DWORD WINAPI GetCurrentPDB16(void)
1319 {
1320     TDB *pTask;
1321
1322     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1323     return MAKELONG(pTask->hPDB, 0); /* FIXME */
1324 }
1325
1326
1327 /***********************************************************************
1328  *           GetCurPID16   (KERNEL.157)
1329  */
1330 DWORD WINAPI GetCurPID16( DWORD unused )
1331 {
1332     return 0;
1333 }
1334
1335
1336 /***********************************************************************
1337  *           GetInstanceData   (KERNEL.54)
1338  */
1339 INT16 WINAPI GetInstanceData16( HINSTANCE16 instance, WORD buffer, INT16 len )
1340 {
1341     char *ptr = (char *)GlobalLock16( instance );
1342     if (!ptr || !len) return 0;
1343     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1344     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1345     return len;
1346 }
1347
1348
1349 /***********************************************************************
1350  *           GetExeVersion   (KERNEL.105)
1351  */
1352 WORD WINAPI GetExeVersion16(void)
1353 {
1354     TDB *pTask;
1355
1356     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1357     return pTask->version;
1358 }
1359
1360
1361 /***********************************************************************
1362  *           SetErrorMode16   (KERNEL.107)
1363  */
1364 UINT16 WINAPI SetErrorMode16( UINT16 mode )
1365 {
1366     TDB *pTask;
1367     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1368     pTask->error_mode = mode;
1369     return SetErrorMode( mode );
1370 }
1371
1372
1373 /***********************************************************************
1374  *           GetDOSEnvironment   (KERNEL.131)
1375  */
1376 SEGPTR WINAPI GetDOSEnvironment16(void)
1377 {
1378     TDB *pTask;
1379
1380     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1381     return PTR_SEG_OFF_TO_SEGPTR( pTask->pdb.environment, 0 );
1382 }
1383
1384
1385 /***********************************************************************
1386  *           GetNumTasks   (KERNEL.152)
1387  */
1388 UINT16 WINAPI GetNumTasks16(void)
1389 {
1390     return nTaskCount;
1391 }
1392
1393
1394 /***********************************************************************
1395  *           GetTaskDS   (KERNEL.155)
1396  *
1397  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1398  * I don't think we need to bother with this.
1399  */
1400 HINSTANCE16 WINAPI GetTaskDS16(void)
1401 {
1402     TDB *pTask;
1403
1404     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1405     return pTask->hInstance;
1406 }
1407
1408 /***********************************************************************
1409  *           GetDummyModuleHandleDS   (KERNEL.602)
1410  */
1411 WORD WINAPI GetDummyModuleHandleDS16(void)
1412 {
1413     TDB *pTask;
1414     WORD selector;
1415
1416     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1417     if (!(pTask->flags & TDBF_WIN32)) return 0;
1418     selector = GlobalHandleToSel16( pTask->hModule );
1419     CURRENT_DS = selector;
1420     return selector;
1421 }
1422
1423 /***********************************************************************
1424  *           IsTask   (KERNEL.320)
1425  */
1426 BOOL16 WINAPI IsTask16( HTASK16 hTask )
1427 {
1428     TDB *pTask;
1429
1430     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1431     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1432     return (pTask->magic == TDB_MAGIC);
1433 }
1434
1435
1436 /***********************************************************************
1437  *           IsWinOldApTask16   (KERNEL.158)
1438  */
1439 BOOL16 WINAPI IsWinOldApTask16( HTASK16 hTask )
1440 {
1441     /* should return bit 0 of byte 0x48 in PSP */
1442     return FALSE;
1443 }
1444
1445 /***********************************************************************
1446  *           SetTaskSignalProc   (KERNEL.38)
1447  */
1448 FARPROC16 WINAPI SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1449 {
1450     TDB *pTask;
1451     FARPROC16 oldProc;
1452
1453     if (!hTask) hTask = GetCurrentTask();
1454     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return NULL;
1455     oldProc = pTask->userhandler;
1456     pTask->userhandler = proc;
1457     return oldProc;
1458 }
1459
1460 /***********************************************************************
1461  *           TASK_CallTaskSignalProc
1462  */
1463 /* ### start build ### */
1464 extern WORD CALLBACK TASK_CallTo16_word_wwwww(FARPROC16,WORD,WORD,WORD,WORD,WORD);
1465 /* ### stop build ### */
1466 void TASK_CallTaskSignalProc( UINT16 uCode, HANDLE16 hTaskOrModule )
1467 {
1468     TDB *pTask = (TDB *)GlobalLock16( GetCurrentTask() );
1469     if ( !pTask || !pTask->userhandler ) return;
1470
1471     TASK_CallTo16_word_wwwww( pTask->userhandler,
1472                               hTaskOrModule, uCode, 0,
1473                               pTask->hInstance, pTask->hQueue );
1474 }
1475
1476 /***********************************************************************
1477  *           SetSigHandler   (KERNEL.140)
1478  */
1479 WORD WINAPI SetSigHandler16( FARPROC16 newhandler, FARPROC16* oldhandler,
1480                            UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1481 {
1482     FIXME("(%p,%p,%p,%d,%d), unimplemented.\n",
1483           newhandler,oldhandler,oldmode,newmode,flag );
1484
1485     if (flag != 1) return 0;
1486     if (!newmode) newhandler = NULL;  /* Default handler */
1487     if (newmode != 4)
1488     {
1489         TDB *pTask;
1490
1491         if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1492         if (oldmode) *oldmode = pTask->signal_flags;
1493         pTask->signal_flags = newmode;
1494         if (oldhandler) *oldhandler = pTask->sighandler;
1495         pTask->sighandler = newhandler;
1496     }
1497     return 0;
1498 }
1499
1500
1501 /***********************************************************************
1502  *           GlobalNotify   (KERNEL.154)
1503  *
1504  * Note that GlobalNotify does _not_ return the old NotifyProc
1505  * -- contrary to LocalNotify !!
1506  */
1507 VOID WINAPI GlobalNotify16( FARPROC16 proc )
1508 {
1509     TDB *pTask;
1510
1511     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1512     pTask->discardhandler = proc;
1513 }
1514
1515
1516 /***********************************************************************
1517  *           GetExePtr   (KERNEL.133)
1518  */
1519 static inline HMODULE16 GetExePtrHelper( HANDLE16 handle, HTASK16 *hTask )
1520 {
1521     char *ptr;
1522     HANDLE16 owner;
1523
1524       /* Check for module handle */
1525
1526     if (!(ptr = GlobalLock16( handle ))) return 0;
1527     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return handle;
1528
1529       /* Search for this handle inside all tasks */
1530
1531     *hTask = hFirstTask;
1532     while (*hTask)
1533     {
1534         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1535         if ((*hTask == handle) ||
1536             (pTask->hInstance == handle) ||
1537             (pTask->hQueue == handle) ||
1538             (pTask->hPDB == handle)) return pTask->hModule;
1539         *hTask = pTask->hNext;
1540     }
1541
1542       /* Check the owner for module handle */
1543
1544     owner = FarGetOwner16( handle );
1545     if (!(ptr = GlobalLock16( owner ))) return 0;
1546     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return owner;
1547
1548       /* Search for the owner inside all tasks */
1549
1550     *hTask = hFirstTask;
1551     while (*hTask)
1552     {
1553         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1554         if ((*hTask == owner) ||
1555             (pTask->hInstance == owner) ||
1556             (pTask->hQueue == owner) ||
1557             (pTask->hPDB == owner)) return pTask->hModule;
1558         *hTask = pTask->hNext;
1559     }
1560
1561     return 0;
1562 }
1563
1564 HMODULE16 WINAPI WIN16_GetExePtr( HANDLE16 handle )
1565 {
1566     HTASK16 hTask = 0;
1567     HMODULE16 hModule = GetExePtrHelper( handle, &hTask );
1568     STACK16FRAME *frame = CURRENT_STACK16;
1569     frame->ecx = hModule;
1570     if (hTask) frame->es = hTask;
1571     return hModule;
1572 }
1573
1574 HMODULE16 WINAPI GetExePtr( HANDLE16 handle )
1575 {
1576     HTASK16 hTask = 0;
1577     return GetExePtrHelper( handle, &hTask );
1578 }
1579
1580
1581 /***********************************************************************
1582  *           TaskFirst   (TOOLHELP.63)
1583  */
1584 BOOL16 WINAPI TaskFirst16( TASKENTRY *lpte )
1585 {
1586     lpte->hNext = hFirstTask;
1587     return TaskNext16( lpte );
1588 }
1589
1590
1591 /***********************************************************************
1592  *           TaskNext   (TOOLHELP.64)
1593  */
1594 BOOL16 WINAPI TaskNext16( TASKENTRY *lpte )
1595 {
1596     TDB *pTask;
1597     INSTANCEDATA *pInstData;
1598
1599     TRACE_(toolhelp)("(%p): task=%04x\n", lpte, lpte->hNext );
1600     if (!lpte->hNext) return FALSE;
1601     pTask = (TDB *)GlobalLock16( lpte->hNext );
1602     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1603     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1604     lpte->hTask         = lpte->hNext;
1605     lpte->hTaskParent   = pTask->hParent;
1606     lpte->hInst         = pTask->hInstance;
1607     lpte->hModule       = pTask->hModule;
1608     lpte->wSS           = SELECTOROF( pTask->teb->cur_stack );
1609     lpte->wSP           = OFFSETOF( pTask->teb->cur_stack );
1610     lpte->wStackTop     = pInstData->stacktop;
1611     lpte->wStackMinimum = pInstData->stackmin;
1612     lpte->wStackBottom  = pInstData->stackbottom;
1613     lpte->wcEvents      = pTask->nEvents;
1614     lpte->hQueue        = pTask->hQueue;
1615     lstrcpynA( lpte->szModule, pTask->module_name, sizeof(lpte->szModule) );
1616     lpte->wPSPOffset    = 0x100;  /*??*/
1617     lpte->hNext         = pTask->hNext;
1618     return TRUE;
1619 }
1620
1621
1622 /***********************************************************************
1623  *           TaskFindHandle   (TOOLHELP.65)
1624  */
1625 BOOL16 WINAPI TaskFindHandle16( TASKENTRY *lpte, HTASK16 hTask )
1626 {
1627     lpte->hNext = hTask;
1628     return TaskNext16( lpte );
1629 }
1630
1631
1632 /***********************************************************************
1633  *           GetAppCompatFlags16   (KERNEL.354)
1634  */
1635 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1636 {
1637     return GetAppCompatFlags( hTask );
1638 }
1639
1640
1641 /***********************************************************************
1642  *           GetAppCompatFlags32   (USER32.206)
1643  */
1644 DWORD WINAPI GetAppCompatFlags( HTASK hTask )
1645 {
1646     TDB *pTask;
1647
1648     if (!hTask) hTask = GetCurrentTask();
1649     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1650     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1651     return pTask->compat_flags;
1652 }