loader/task.c

   1 /*
   2  * Task functions
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  */
   6
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <assert.h>
  10 #include <unistd.h>
  11
  12 #include "wine/winbase16.h"
  13 #include "user.h"
  14 #include "callback.h"
  15 #include "drive.h"
  16 #include "file.h"
  17 #include "global.h"
  18 #include "instance.h"
  19 #include "message.h"
  20 #include "miscemu.h"
  21 #include "module.h"
  22 #include "neexe.h"
  23 #include "peexe.h"
  24 #include "pe_image.h"
  25 #include "process.h"
  26 #include "queue.h"
  27 #include "selectors.h"
  28 #include "stackframe.h"
  29 #include "task.h"
  30 #include "thread.h"
  31 #include "toolhelp.h"
  32 #include "winnt.h"
  33 #include "winsock.h"
  34 #include "thread.h"
  35 #include "syslevel.h"
  36 #include "debugtools.h"
  37 #include "dosexe.h"
  38 #include "services.h"
  39 #include "server.h"
  40
  41 DECLARE_DEBUG_CHANNEL(relay)
  42 DECLARE_DEBUG_CHANNEL(task)
  43 DECLARE_DEBUG_CHANNEL(toolhelp)
  44
  45   /* Min. number of thunks allocated when creating a new segment */
  46 #define MIN_THUNKS  32
  47
  48   /* Pointer to function to switch to a larger stack */
  49 int (*IF1632_CallLargeStack)( int (*func)(), void *arg ) = NULL;
  50
  51 static THHOOK DefaultThhook = { 0 };
  52 THHOOK *pThhook = &DefaultThhook;
  53
  54 #define hCurrentTask (pThhook->CurTDB)
  55 #define hFirstTask   (pThhook->HeadTDB)
  56 #define hLockedTask  (pThhook->LockTDB)
  57
  58 static UINT16 nTaskCount = 0;
  59
  60
  61 /***********************************************************************
  62  *           TASK_InstallTHHook
  63  */
  64 void TASK_InstallTHHook( THHOOK *pNewThhook )
  65 {
  66      THHOOK *pOldThhook = pThhook;
  67
  68      pThhook = pNewThhook? pNewThhook : &DefaultThhook;
  69
  70      *pThhook = *pOldThhook;
  71 }
  72
  73 /***********************************************************************
  74  *           TASK_GetNextTask
  75  */
  76 HTASK16 TASK_GetNextTask( HTASK16 hTask )
  77 {
  78     TDB* pTask = (TDB*)GlobalLock16(hTask);
  79
  80     if (pTask->hNext) return pTask->hNext;
  81     return (hFirstTask != hTask) ? hFirstTask : 0;
  82 }
  83
  84 /***********************************************************************
  85  *           TASK_LinkTask
  86  */
  87 static void TASK_LinkTask( HTASK16 hTask )
  88 {
  89     HTASK16 *prevTask;
  90     TDB *pTask;
  91
  92     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
  93     prevTask = &hFirstTask;
  94     while (*prevTask)
  95     {
  96         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
  97         if (prevTaskPtr->priority >= pTask->priority) break;
  98         prevTask = &prevTaskPtr->hNext;
  99     }
 100     pTask->hNext = *prevTask;
 101     *prevTask = hTask;
 102     nTaskCount++;
 103 }
 104
 105
 106 /***********************************************************************
 107  *           TASK_UnlinkTask
 108  */
 109 static void TASK_UnlinkTask( HTASK16 hTask )
 110 {
 111     HTASK16 *prevTask;
 112     TDB *pTask;
 113
 114     prevTask = &hFirstTask;
 115     while (*prevTask && (*prevTask != hTask))
 116     {
 117         pTask = (TDB *)GlobalLock16( *prevTask );
 118         prevTask = &pTask->hNext;
 119     }
 120     if (*prevTask)
 121     {
 122         pTask = (TDB *)GlobalLock16( *prevTask );
 123         *prevTask = pTask->hNext;
 124         pTask->hNext = 0;
 125         nTaskCount--;
 126     }
 127 }
 128
 129
 130 /***********************************************************************
 131  *           TASK_CreateThunks
 132  *
 133  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 134  * and containing 'count' entries.
 135  */
 136 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 137 {
 138     int i;
 139     WORD free;
 140     THUNKS *pThunk;
 141
 142     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 143     pThunk->next = 0;
 144     pThunk->magic = THUNK_MAGIC;
 145     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 146     free = pThunk->free;
 147     for (i = 0; i < count-1; i++)
 148     {
 149         free += 8;  /* Offset of next thunk */
 150         pThunk->thunks[4*i] = free;
 151     }
 152     pThunk->thunks[4*i] = 0;  /* Last thunk */
 153 }
 154
 155
 156 /***********************************************************************
 157  *           TASK_AllocThunk
 158  *
 159  * Allocate a thunk for MakeProcInstance().
 160  */
 161 static SEGPTR TASK_AllocThunk( HTASK16 hTask )
 162 {
 163     TDB *pTask;
 164     THUNKS *pThunk;
 165     WORD sel, base;
 166
 167     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 168     sel = pTask->hCSAlias;
 169     pThunk = &pTask->thunks;
 170     base = (int)pThunk - (int)pTask;
 171     while (!pThunk->free)
 172     {
 173         sel = pThunk->next;
 174         if (!sel)  /* Allocate a new segment */
 175         {
 176             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 177                                 pTask->hPDB, TRUE, FALSE, FALSE );
 178             if (!sel) return (SEGPTR)0;
 179             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 180             pThunk->next = sel;
 181         }
 182         pThunk = (THUNKS *)GlobalLock16( sel );
 183         base = 0;
 184     }
 185     base += pThunk->free;
 186     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 187     return PTR_SEG_OFF_TO_SEGPTR( sel, base );
 188 }
 189
 190
 191 /***********************************************************************
 192  *           TASK_FreeThunk
 193  *
 194  * Free a MakeProcInstance() thunk.
 195  */
 196 static BOOL TASK_FreeThunk( HTASK16 hTask, SEGPTR thunk )
 197 {
 198     TDB *pTask;
 199     THUNKS *pThunk;
 200     WORD sel, base;
 201
 202     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 203     sel = pTask->hCSAlias;
 204     pThunk = &pTask->thunks;
 205     base = (int)pThunk - (int)pTask;
 206     while (sel && (sel != HIWORD(thunk)))
 207     {
 208         sel = pThunk->next;
 209         pThunk = (THUNKS *)GlobalLock16( sel );
 210         base = 0;
 211     }
 212     if (!sel) return FALSE;
 213     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 214     pThunk->free = LOWORD(thunk) - base;
 215     return TRUE;
 216 }
 217
 218
 219 /***********************************************************************
 220  *           TASK_CallToStart
 221  *
 222  * 32-bit entry point for a new task. This function is responsible for
 223  * setting up the registers and jumping to the 16-bit entry point.
 224  */
 225 void TASK_CallToStart(void)
 226 {
 227     TDB *pTask = (TDB *)GlobalLock16( GetCurrentTask() );
 228     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 229     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 230     CONTEXT86 context;
 231
 232     /* Add task to 16-bit scheduler pool */
 233     TASK_Reschedule();
 234
 235     /* Registers at initialization must be:
 236      * ax   zero
 237      * bx   stack size in bytes
 238      * cx   heap size in bytes
 239      * si   previous app instance
 240      * di   current app instance
 241      * bp   zero
 242      * es   selector to the PSP
 243      * ds   dgroup of the application
 244      * ss   stack selector
 245      * sp   top of the stack
 246      */
 247
 248     memset( &context, 0, sizeof(context) );
 249     CS_reg(&context)  = GlobalHandleToSel16(pSegTable[pModule->cs - 1].hSeg);
 250     DS_reg(&context)  = GlobalHandleToSel16(pTask->hInstance);
 251     ES_reg(&context)  = pTask->hPDB;
 252     EIP_reg(&context) = pModule->ip;
 253     EBX_reg(&context) = pModule->stack_size;
 254     ECX_reg(&context) = pModule->heap_size;
 255     EDI_reg(&context) = pTask->hInstance;
 256     ESI_reg(&context) = pTask->hPrevInstance;
 257
 258     TRACE_(task)("Starting main program: cs:ip=%04lx:%04lx ds=%04lx ss:sp=%04x:%04x\n",
 259                   CS_reg(&context), EIP_reg(&context), DS_reg(&context),
 260                   SELECTOROF(pTask->teb->cur_stack),
 261                   OFFSETOF(pTask->teb->cur_stack) );
 262
 263     Callbacks->CallRegisterShortProc( &context, 0 );
 264 }
 265
 266
 267 /***********************************************************************
 268  *           TASK_Create
 269  *
 270  * NOTE: This routine might be called by a Win32 thread. Thus, we need
 271  *       to be careful to protect global data structures. We do this
 272  *       by entering the Win16Lock while linking the task into the
 273  *       global task list.
 274  */
 275 BOOL TASK_Create( NE_MODULE *pModule, UINT16 cmdShow)
 276 {
 277     HTASK16 hTask;
 278     TDB *pTask;
 279     LPSTR cmd_line;
 280     char name[10];
 281     PDB *pdb32 = PROCESS_Current();
 282
 283       /* Allocate the task structure */
 284
 285     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 286                           pModule->self, FALSE, FALSE, FALSE );
 287     if (!hTask) return FALSE;
 288     pTask = (TDB *)GlobalLock16( hTask );
 289
 290     /* Fill the task structure */
 291
 292     pTask->nEvents       = 0;
 293     pTask->hSelf         = hTask;
 294     pTask->flags         = 0;
 295
 296     if (pModule->flags & NE_FFLAGS_WIN32)
 297         pTask->flags    |= TDBF_WIN32;
 298     if (pModule->lpDosTask)
 299         pTask->flags    |= TDBF_WINOLDAP;
 300
 301     pTask->hInstance     = pModule->self;
 302     pTask->hPrevInstance = 0;
 303     /* NOTE: for 16-bit tasks, the instance handles are updated later on
 304              in NE_InitProcess */
 305
 306     pTask->version       = pModule->expected_version;
 307     pTask->hModule       = pModule->self;
 308     pTask->hParent       = GetCurrentTask();
 309     pTask->magic         = TDB_MAGIC;
 310     pTask->nCmdShow      = cmdShow;
 311     pTask->teb           = NtCurrentTeb();
 312     pTask->curdrive      = DRIVE_GetCurrentDrive() | 0x80;
 313     strcpy( pTask->curdir, "\\" );
 314     lstrcpynA( pTask->curdir + 1, DRIVE_GetDosCwd( DRIVE_GetCurrentDrive() ),
 315                  sizeof(pTask->curdir) - 1 );
 316
 317       /* Create the thunks block */
 318
 319     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 320
 321       /* Copy the module name */
 322
 323     GetModuleName16( pModule->self, name, sizeof(name) );
 324     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 325
 326       /* Allocate a selector for the PDB */
 327
 328     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB16),
 329                                     pModule->self, FALSE, FALSE, FALSE, NULL );
 330
 331       /* Fill the PDB */
 332
 333     pTask->pdb.int20 = 0x20cd;
 334     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 335     PUT_DWORD(&pTask->pdb.dispatcher[1], (DWORD)NE_GetEntryPoint(
 336            GetModuleHandle16("KERNEL"), 102 ));  /* KERNEL.102 is DOS3Call() */
 337     pTask->pdb.savedint22 = INT_GetPMHandler( 0x22 );
 338     pTask->pdb.savedint23 = INT_GetPMHandler( 0x23 );
 339     pTask->pdb.savedint24 = INT_GetPMHandler( 0x24 );
 340     pTask->pdb.fileHandlesPtr =
 341         PTR_SEG_OFF_TO_SEGPTR( GlobalHandleToSel16(pTask->hPDB),
 342                                (int)&((PDB16 *)0)->fileHandles );
 343     pTask->pdb.hFileHandles = 0;
 344     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 345     pTask->pdb.environment    = pdb32->env_db->env_sel;
 346     pTask->pdb.nbFiles        = 20;
 347
 348     /* Fill the command line */
 349
 350     cmd_line = pdb32->env_db->cmd_line;
 351     while (*cmd_line && (*cmd_line != ' ') && (*cmd_line != '\t')) cmd_line++;
 352     while ((*cmd_line == ' ') || (*cmd_line == '\t')) cmd_line++;
 353     lstrcpynA( pTask->pdb.cmdLine+1, cmd_line, sizeof(pTask->pdb.cmdLine)-1);
 354     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 355
 356       /* Get the compatibility flags */
 357
 358     pTask->compat_flags = GetProfileIntA( "Compatibility", name, 0 );
 359
 360       /* Allocate a code segment alias for the TDB */
 361
 362     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 363                                           sizeof(TDB), pTask->hPDB, TRUE,
 364                                           FALSE, FALSE, NULL );
 365
 366       /* Set the owner of the environment block */
 367
 368     FarSetOwner16( pTask->pdb.environment, pTask->hPDB );
 369
 370       /* Default DTA overwrites command-line */
 371
 372     pTask->dta = PTR_SEG_OFF_TO_SEGPTR( pTask->hPDB,
 373                                 (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 374
 375     /* Create scheduler event for 16-bit tasks */
 376
 377     if ( !(pTask->flags & TDBF_WIN32) )
 378     {
 379         pTask->hEvent = CreateEventA( NULL, TRUE, FALSE, NULL );
 380         pTask->hEvent = ConvertToGlobalHandle( pTask->hEvent );
 381     }
 382
 383     /* Enter task handle into thread and process */
 384
 385     pTask->teb->htask16 = pTask->teb->process->task = hTask;
 386     TRACE_(task)("module='%s' cmdline='%s' task=%04x\n", name, cmd_line, hTask );
 387
 388     /* Add the task to the linked list */
 389
 390     SYSLEVEL_EnterWin16Lock();
 391     TASK_LinkTask( hTask );
 392     SYSLEVEL_LeaveWin16Lock();
 393
 394     return TRUE;
 395 }
 396
 397 /***********************************************************************
 398  *           TASK_DeleteTask
 399  */
 400 static void TASK_DeleteTask( HTASK16 hTask )
 401 {
 402     TDB *pTask;
 403     HGLOBAL16 hPDB;
 404
 405     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 406     hPDB = pTask->hPDB;
 407
 408     pTask->magic = 0xdead; /* invalidate signature */
 409
 410     /* Delete the Win32 part of the task */
 411
 412 /*    PROCESS_FreePDB( pTask->teb->process ); FIXME */
 413 /*    K32OBJ_DecCount( &pTask->teb->header ); FIXME */
 414
 415     /* Free the selector aliases */
 416
 417     GLOBAL_FreeBlock( pTask->hCSAlias );
 418     GLOBAL_FreeBlock( pTask->hPDB );
 419
 420     /* Free the task module */
 421
 422     FreeModule16( pTask->hModule );
 423
 424     /* Free the task structure itself */
 425
 426     GlobalFree16( hTask );
 427
 428     /* Free all memory used by this task (including the 32-bit stack, */
 429     /* the environment block and the thunk segments). */
 430
 431     GlobalFreeAll16( hPDB );
 432 }
 433
 434 /***********************************************************************
 435  *           TASK_KillTask
 436  */
 437 void TASK_KillTask( HTASK16 hTask )
 438 {
 439     TDB *pTask;
 440
 441     /* Enter the Win16Lock to protect global data structures */
 442     SYSLEVEL_EnterWin16Lock();
 443
 444     if ( !hTask ) hTask = GetCurrentTask();
 445     pTask = (TDB *)GlobalLock16( hTask );
 446     if ( !pTask )
 447     {
 448         SYSLEVEL_LeaveWin16Lock();
 449         return;
 450     }
 451
 452     TRACE_(task)("Killing task %04x\n", hTask );
 453
 454     /* Delete active sockets */
 455
 456     if( pTask->pwsi )
 457         WINSOCK_DeleteTaskWSI( pTask, pTask->pwsi );
 458
 459 #ifdef MZ_SUPPORTED
 460 {
 461     /* Kill DOS VM task */
 462     NE_MODULE *pModule = NE_GetPtr( pTask->hModule );
 463     if ( pModule->lpDosTask )
 464         MZ_KillModule( pModule->lpDosTask );
 465 }
 466 #endif
 467
 468     /* Perform USER cleanup */
 469
 470     if (pTask->userhandler)
 471         pTask->userhandler( hTask, USIG16_TERMINATION, 0,
 472                             pTask->hInstance, pTask->hQueue );
 473
 474     PROCESS_CallUserSignalProc( USIG_PROCESS_EXIT, 0 );
 475     PROCESS_CallUserSignalProc( USIG_THREAD_EXIT, 0 );     /* FIXME */
 476     PROCESS_CallUserSignalProc( USIG_PROCESS_DESTROY, 0 );
 477
 478     if (nTaskCount <= 1)
 479     {
 480         TRACE_(task)("this is the last task, exiting\n" );
 481         ExitKernel16();
 482     }
 483
 484     /* FIXME: Hack! Send a message to the initial task so that
 485      * the GetMessage wakes up and the initial task can check whether
 486      * it is the only remaining one and terminate itself ...
 487      * The initial task should probably install hooks or something
 488      * to get informed about task termination :-/
 489      */
 490     Callout.PostAppMessage16( PROCESS_Initial()->task, WM_NULL, 0, 0 );
 491
 492     /* Remove the task from the list to be sure we never switch back to it */
 493     TASK_UnlinkTask( hTask );
 494     if( nTaskCount )
 495     {
 496         TDB* p = (TDB *)GlobalLock16( hFirstTask );
 497         while( p )
 498         {
 499             if( p->hYieldTo == hTask ) p->hYieldTo = 0;
 500             p = (TDB *)GlobalLock16( p->hNext );
 501         }
 502     }
 503
 504     pTask->nEvents = 0;
 505
 506     if ( hLockedTask == hTask )
 507         hLockedTask = 0;
 508
 509     TASK_DeleteTask( hTask );
 510
 511     /* When deleting the current task ... */
 512     if ( hTask == hCurrentTask )
 513     {
 514         DWORD lockCount;
 515
 516         /* ... schedule another one ... */
 517         TASK_Reschedule();
 518
 519         /* ... and completely release the Win16Lock, just in case. */
 520         ReleaseThunkLock( &lockCount );
 521
 522         return;
 523     }
 524
 525     SYSLEVEL_LeaveWin16Lock();
 526 }
 527
 528 /***********************************************************************
 529  *           TASK_Reschedule
 530  *
 531  * This is where all the magic of task-switching happens!
 532  *
 533  * 16-bit Windows performs non-preemptive (cooperative) multitasking.
 534  * This means that each 16-bit task runs until it voluntarily yields
 535  * control, at which point the scheduler gets active and selects the
 536  * next task to run.
 537  *
 538  * In Wine, all processes, even 16-bit ones, are scheduled preemptively
 539  * by the standard scheduler of the underlying OS.  As many 16-bit apps
 540  * *rely* on the behaviour of the Windows scheduler, however, we have
 541  * to simulate that behaviour.
 542  *
 543  * This is achieved as follows: every 16-bit task is at time (except
 544  * during task creation and deletion) in one of two states: either it
 545  * is the one currently running, then the global variable hCurrentTask
 546  * contains its task handle, or it is not currently running, then it
 547  * is blocked on a special scheduler event, a global handle to which
 548  * is stored in the task struct.
 549  *
 550  * When the current task yields control, this routine gets called. Its
 551  * purpose is to determine the next task to be active, signal the
 552  * scheduler event of that task, and then put the current task to sleep
 553  * waiting for *its* scheduler event to get signalled again.
 554  *
 555  * This routine can get called in a few other special situations as well:
 556  *
 557  * - On creation of a 16-bit task, the Unix process executing the task
 558  *   calls TASK_Reschedule once it has completed its initialization.
 559  *   At this point, the task needs to be blocked until its scheduler
 560  *   event is signalled the first time (this will be done by the parent
 561  *   process to get the task up and running).
 562  *
 563  * - When the task currently running terminates itself, this routine gets
 564  *   called and has to schedule another task, *without* blocking the
 565  *   terminating task.
 566  *
 567  * - When a 32-bit thread posts an event for a 16-bit task, it might be
 568  *   the case that *no* 16-bit task is currently running.  In this case
 569  *   the task that has now an event pending is to be scheduled.
 570  *
 571  */
 572 void TASK_Reschedule(void)
 573 {
 574     TDB *pOldTask = NULL, *pNewTask = NULL;
 575     HTASK16 hOldTask = 0, hNewTask = 0;
 576     enum { MODE_YIELD, MODE_SLEEP, MODE_WAKEUP } mode;
 577     DWORD lockCount;
 578
 579     SYSLEVEL_EnterWin16Lock();
 580
 581     /* Check what we need to do */
 582     hOldTask = GetCurrentTask();
 583     pOldTask = (TDB *)GlobalLock16( hOldTask );
 584     TRACE_(task)( "entered with hCurrentTask %04x by hTask %04x (pid %ld)\n",
 585                   hCurrentTask, hOldTask, (long) getpid() );
 586
 587     if ( pOldTask && THREAD_IsWin16( NtCurrentTeb() ) )
 588     {
 589         /* We are called by an active (non-deleted) 16-bit task */
 590
 591         /* If we don't even have a current task, or else the current
 592            task has yielded, we'll need to schedule a new task and
 593            (possibly) put the calling task to sleep.  Otherwise, we
 594            only block the caller. */
 595
 596         if ( !hCurrentTask || hCurrentTask == hOldTask )
 597             mode = MODE_YIELD;
 598         else
 599             mode = MODE_SLEEP;
 600     }
 601     else
 602     {
 603         /* We are called by a deleted 16-bit task or a 32-bit thread */
 604
 605         /* The only situation where we need to do something is if we
 606            now do not have a current task.  Then, we'll need to wake up
 607            some task that has events pending. */
 608
 609         if ( !hCurrentTask || hCurrentTask == hOldTask )
 610             mode = MODE_WAKEUP;
 611         else
 612         {
 613             /* nothing to do */
 614             SYSLEVEL_LeaveWin16Lock();
 615             return;
 616         }
 617     }
 618
 619     /* Find a task to yield to: check for DirectedYield() */
 620     if ( mode == MODE_YIELD && pOldTask && pOldTask->hYieldTo )
 621     {
 622         hNewTask = pOldTask->hYieldTo;
 623         pNewTask = (TDB *)GlobalLock16( hNewTask );
 624         if( !pNewTask || !pNewTask->nEvents) hNewTask = 0;
 625         pOldTask->hYieldTo = 0;
 626     }
 627
 628     /* Find a task to yield to: check for pending events */
 629     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && !hNewTask )
 630     {
 631         hNewTask = hFirstTask;
 632         while (hNewTask)
 633         {
 634             pNewTask = (TDB *)GlobalLock16( hNewTask );
 635
 636             TRACE_(task)( "\ttask = %04x, events = %i\n",
 637                           hNewTask, pNewTask->nEvents );
 638
 639             if (pNewTask->nEvents) break;
 640             hNewTask = pNewTask->hNext;
 641         }
 642         if (hLockedTask && (hNewTask != hLockedTask)) hNewTask = 0;
 643     }
 644
 645     /* If we are still the task with highest priority, just return ... */
 646     if ( mode == MODE_YIELD && hNewTask == hCurrentTask )
 647     {
 648         TRACE_(task)("returning to the current task (%04x)\n", hCurrentTask );
 649         SYSLEVEL_LeaveWin16Lock();
 650
 651         /* Allow Win32 threads to thunk down even while a Win16 task is
 652            in a tight PeekMessage() or Yield() loop ... */
 653         ReleaseThunkLock( &lockCount );
 654         RestoreThunkLock( lockCount );
 655         return;
 656     }
 657
 658     /* If no task to yield to found, suspend 16-bit scheduler ... */
 659     if ( mode == MODE_YIELD && !hNewTask )
 660     {
 661         TRACE_(task)("No currently active task\n");
 662         hCurrentTask = 0;
 663     }
 664
 665     /* If we found a task to wake up, do it ... */
 666     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && hNewTask )
 667     {
 668         TRACE_(task)("Switching to task %04x (%.8s)\n",
 669                       hNewTask, pNewTask->module_name );
 670
 671         pNewTask->priority++;
 672         TASK_UnlinkTask( hNewTask );
 673         TASK_LinkTask( hNewTask );
 674         pNewTask->priority--;
 675
 676         hCurrentTask = hNewTask;
 677         SetEvent( pNewTask->hEvent );
 678
 679         /* This is set just in case some app reads it ... */
 680         pNewTask->ss_sp = pNewTask->teb->cur_stack;
 681     }
 682
 683     /* If we need to put the current task to sleep, do it ... */
 684     if ( (mode == MODE_YIELD || mode == MODE_SLEEP) && hOldTask != hCurrentTask )
 685     {
 686         ResetEvent( pOldTask->hEvent );
 687
 688         ReleaseThunkLock( &lockCount );
 689         SYSLEVEL_CheckNotLevel( 1 );
 690         WaitForSingleObject( pOldTask->hEvent, INFINITE );
 691         RestoreThunkLock( lockCount );
 692     }
 693
 694     SYSLEVEL_LeaveWin16Lock();
 695 }
 696
 697 /***********************************************************************
 698  *           InitTask  (KERNEL.91)
 699  *
 700  * Called by the application startup code.
 701  */
 702 void WINAPI InitTask16( CONTEXT86 *context )
 703 {
 704     TDB *pTask;
 705     INSTANCEDATA *pinstance;
 706     SEGPTR ptr;
 707
 708     EAX_reg(context) = 0;
 709     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
 710
 711     /* Note: we need to trust that BX/CX contain the stack/heap sizes,
 712        as some apps, notably Visual Basic apps, *modify* the heap/stack
 713        size of the instance data segment before calling InitTask() */
 714
 715     /* Initialize the INSTANCEDATA structure */
 716     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 717     pinstance->stackmin    = OFFSETOF( pTask->teb->cur_stack );
 718     pinstance->stackbottom = pinstance->stackmin; /* yup, that's right. Confused me too. */
 719     pinstance->stacktop    = ( pinstance->stackmin > BX_reg(context)?
 720                                pinstance->stackmin - BX_reg(context) : 0 ) + 150;
 721
 722     /* Initialize the local heap */
 723     if ( CX_reg(context) )
 724         LocalInit16( pTask->hInstance, 0, CX_reg(context) );
 725
 726     /* Initialize implicitly loaded DLLs */
 727     NE_InitializeDLLs( pTask->hModule );
 728
 729     /* Registers on return are:
 730      * ax     1 if OK, 0 on error
 731      * cx     stack limit in bytes
 732      * dx     cmdShow parameter
 733      * si     instance handle of the previous instance
 734      * di     instance handle of the new task
 735      * es:bx  pointer to command-line inside PSP
 736      *
 737      * 0 (=%bp) is pushed on the stack
 738      */
 739     ptr = stack16_push( sizeof(WORD) );
 740     *(WORD *)PTR_SEG_TO_LIN(ptr) = 0;
 741     ESP_reg(context) -= 2;
 742
 743     EAX_reg(context) = 1;
 744
 745     if (!pTask->pdb.cmdLine[0]) EBX_reg(context) = 0x80;
 746     else
 747     {
 748         LPBYTE p = &pTask->pdb.cmdLine[1];
 749         while ((*p == ' ') || (*p == '\t')) p++;
 750         EBX_reg(context) = 0x80 + (p - pTask->pdb.cmdLine);
 751     }
 752     ECX_reg(context) = pinstance->stacktop;
 753     EDX_reg(context) = pTask->nCmdShow;
 754     ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 755     EDI_reg(context) = (DWORD)pTask->hInstance;
 756     ES_reg (context) = (WORD)pTask->hPDB;
 757 }
 758
 759
 760 /***********************************************************************
 761  *           WaitEvent  (KERNEL.30)
 762  */
 763 BOOL16 WINAPI WaitEvent16( HTASK16 hTask )
 764 {
 765     TDB *pTask;
 766
 767     if (!hTask) hTask = GetCurrentTask();
 768     pTask = (TDB *)GlobalLock16( hTask );
 769
 770     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 771     {
 772         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 773         return TRUE;
 774     }
 775
 776     if (pTask->nEvents > 0)
 777     {
 778         pTask->nEvents--;
 779         return FALSE;
 780     }
 781     TASK_Reschedule();
 782
 783     /* When we get back here, we have an event */
 784
 785     if (pTask->nEvents > 0) pTask->nEvents--;
 786     return TRUE;
 787 }
 788
 789
 790 /***********************************************************************
 791  *           PostEvent  (KERNEL.31)
 792  */
 793 void WINAPI PostEvent16( HTASK16 hTask )
 794 {
 795     TDB *pTask;
 796
 797     if (!hTask) hTask = GetCurrentTask();
 798     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 799
 800     if ( !THREAD_IsWin16( pTask->teb ) )
 801     {
 802         FIXME_(task)("called for Win32 thread (%04x)!\n", pTask->teb->teb_sel );
 803         return;
 804     }
 805
 806     pTask->nEvents++;
 807
 808     /* If we are a 32-bit task, we might need to wake up the 16-bit scheduler */
 809     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 810         TASK_Reschedule();
 811 }
 812
 813
 814 /***********************************************************************
 815  *           SetPriority  (KERNEL.32)
 816  */
 817 void WINAPI SetPriority16( HTASK16 hTask, INT16 delta )
 818 {
 819     TDB *pTask;
 820     INT16 newpriority;
 821
 822     if (!hTask) hTask = GetCurrentTask();
 823     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 824     newpriority = pTask->priority + delta;
 825     if (newpriority < -32) newpriority = -32;
 826     else if (newpriority > 15) newpriority = 15;
 827
 828     pTask->priority = newpriority + 1;
 829     TASK_UnlinkTask( hTask );
 830     TASK_LinkTask( hTask );
 831     pTask->priority--;
 832 }
 833
 834
 835 /***********************************************************************
 836  *           LockCurrentTask  (KERNEL.33)
 837  */
 838 HTASK16 WINAPI LockCurrentTask16( BOOL16 bLock )
 839 {
 840     if (bLock) hLockedTask = GetCurrentTask();
 841     else hLockedTask = 0;
 842     return hLockedTask;
 843 }
 844
 845
 846 /***********************************************************************
 847  *           IsTaskLocked  (KERNEL.122)
 848  */
 849 HTASK16 WINAPI IsTaskLocked16(void)
 850 {
 851     return hLockedTask;
 852 }
 853
 854
 855 /***********************************************************************
 856  *           OldYield  (KERNEL.117)
 857  */
 858 void WINAPI OldYield16(void)
 859 {
 860     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 861
 862     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 863     {
 864         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 865         return;
 866     }
 867
 868     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 869     TASK_Reschedule();
 870     if (pCurTask) pCurTask->nEvents--;
 871 }
 872
 873 /***********************************************************************
 874  *           WIN32_OldYield16  (KERNEL.447)
 875  */
 876 void WINAPI WIN32_OldYield16(void)
 877 {
 878    DWORD count;
 879
 880    ReleaseThunkLock(&count);
 881    RestoreThunkLock(count);
 882 }
 883
 884 /***********************************************************************
 885  *           DirectedYield  (KERNEL.150)
 886  */
 887 void WINAPI DirectedYield16( HTASK16 hTask )
 888 {
 889     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 890
 891     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 892     {
 893         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 894         return;
 895     }
 896
 897     TRACE_(task)("%04x: DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 898
 899     pCurTask->hYieldTo = hTask;
 900     OldYield16();
 901
 902     TRACE_(task)("%04x: back from DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 903 }
 904
 905 /***********************************************************************
 906  *           Yield16  (KERNEL.29)
 907  */
 908 void WINAPI Yield16(void)
 909 {
 910     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 911
 912     if (pCurTask) pCurTask->hYieldTo = 0;
 913     if (pCurTask && pCurTask->hQueue) Callout.UserYield16();
 914     else OldYield16();
 915 }
 916
 917 /***********************************************************************
 918  *           KERNEL_490  (KERNEL.490)
 919  */
 920 HTASK16 WINAPI KERNEL_490( HTASK16 someTask )
 921 {
 922     if ( !someTask ) return 0;
 923
 924     FIXME_(task)("(%04x): stub\n", someTask );
 925     return 0;
 926 }
 927
 928 /***********************************************************************
 929  *           MakeProcInstance16  (KERNEL.51)
 930  */
 931 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 932 {
 933     BYTE *thunk,*lfunc;
 934     SEGPTR thunkaddr;
 935
 936     if (!func) {
 937       ERR_(task)("Ouch ! MakeProcInstance called with func == NULL !\n");
 938       return (FARPROC16)0; /* Windows seems to do the same */
 939     }
 940     if (!hInstance) hInstance = CURRENT_DS;
 941     thunkaddr = TASK_AllocThunk( GetCurrentTask() );
 942     if (!thunkaddr) return (FARPROC16)0;
 943     thunk = PTR_SEG_TO_LIN( thunkaddr );
 944     lfunc = PTR_SEG_TO_LIN( func );
 945
 946     TRACE_(task)("(%08lx,%04x): got thunk %08lx\n",
 947                   (DWORD)func, hInstance, (DWORD)thunkaddr );
 948     if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) ||
 949         ((lfunc[0]==0x1e) && (lfunc[1]==0x58))
 950     ) {
 951         FIXME_(task)("thunk would be useless for %p, overwriting with nop;nop;\n", func );
 952         lfunc[0]=0x90; /* nop */
 953         lfunc[1]=0x90; /* nop */
 954     }
 955
 956     *thunk++ = 0xb8;    /* movw instance, %ax */
 957     *thunk++ = (BYTE)(hInstance & 0xff);
 958     *thunk++ = (BYTE)(hInstance >> 8);
 959     *thunk++ = 0xea;    /* ljmp func */
 960     *(DWORD *)thunk = (DWORD)func;
 961     return (FARPROC16)thunkaddr;
 962 }
 963
 964
 965 /***********************************************************************
 966  *           FreeProcInstance16  (KERNEL.52)
 967  */
 968 void WINAPI FreeProcInstance16( FARPROC16 func )
 969 {
 970     TRACE_(task)("(%08lx)\n", (DWORD)func );
 971     TASK_FreeThunk( GetCurrentTask(), (SEGPTR)func );
 972 }
 973
 974
 975 /**********************************************************************
 976  *          GetCodeHandle    (KERNEL.93)
 977  */
 978 HANDLE16 WINAPI GetCodeHandle16( FARPROC16 proc )
 979 {
 980     HANDLE16 handle;
 981     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
 982
 983     /* Return the code segment containing 'proc'. */
 984     /* Not sure if this is really correct (shouldn't matter that much). */
 985
 986     /* Check if it is really a thunk */
 987     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
 988         handle = GlobalHandle16( thunk[6] + (thunk[7] << 8) );
 989     else
 990         handle = GlobalHandle16( HIWORD(proc) );
 991
 992     return handle;
 993 }
 994
 995 /**********************************************************************
 996  *          GetCodeInfo    (KERNEL.104)
 997  */
 998 VOID WINAPI GetCodeInfo16( FARPROC16 proc, SEGINFO *segInfo )
 999 {
1000     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
1001     NE_MODULE *pModule = NULL;
1002     SEGTABLEENTRY *pSeg = NULL;
1003     WORD segNr;
1004
1005     /* proc is either a thunk, or else a pair of module handle
1006        and segment number. In the first case, we also need to
1007        extract module and segment number. */
1008
1009     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1010     {
1011         WORD selector = thunk[6] + (thunk[7] << 8);
1012         pModule = NE_GetPtr( GlobalHandle16( selector ) );
1013         pSeg = pModule? NE_SEG_TABLE( pModule ) : NULL;
1014
1015         if ( pModule )
1016             for ( segNr = 0; segNr < pModule->seg_count; segNr++, pSeg++ )
1017                 if ( GlobalHandleToSel16(pSeg->hSeg) == selector )
1018                     break;
1019
1020         if ( pModule && segNr >= pModule->seg_count )
1021             pSeg = NULL;
1022     }
1023     else
1024     {
1025         pModule = NE_GetPtr( HIWORD( proc ) );
1026         segNr   = LOWORD( proc );
1027
1028         if ( pModule && segNr < pModule->seg_count )
1029             pSeg = NE_SEG_TABLE( pModule ) + segNr;
1030     }
1031
1032     /* fill in segment information */
1033
1034     segInfo->offSegment = pSeg? pSeg->filepos : 0;
1035     segInfo->cbSegment  = pSeg? pSeg->size : 0;
1036     segInfo->flags      = pSeg? pSeg->flags : 0;
1037     segInfo->cbAlloc    = pSeg? pSeg->minsize : 0;
1038     segInfo->h          = pSeg? pSeg->hSeg : 0;
1039     segInfo->alignShift = pModule? pModule->alignment : 0;
1040 }
1041
1042
1043 /**********************************************************************
1044  *          DefineHandleTable16    (KERNEL.94)
1045  */
1046 BOOL16 WINAPI DefineHandleTable16( WORD wOffset )
1047 {
1048     return TRUE;  /* FIXME */
1049 }
1050
1051
1052 /***********************************************************************
1053  *           SetTaskQueue  (KERNEL.34)
1054  */
1055 HQUEUE16 WINAPI SetTaskQueue16( HTASK16 hTask, HQUEUE16 hQueue )
1056 {
1057     HQUEUE16 hPrev;
1058     TDB *pTask;
1059
1060     if (!hTask) hTask = GetCurrentTask();
1061     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1062
1063     hPrev = pTask->hQueue;
1064     pTask->hQueue = hQueue;
1065
1066     return hPrev;
1067 }
1068
1069
1070 /***********************************************************************
1071  *           GetTaskQueue  (KERNEL.35)
1072  */
1073 HQUEUE16 WINAPI GetTaskQueue16( HTASK16 hTask )
1074 {
1075     TDB *pTask;
1076
1077     if (!hTask) hTask = GetCurrentTask();
1078     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1079     return pTask->hQueue;
1080 }
1081
1082 /***********************************************************************
1083  *           SetThreadQueue  (KERNEL.463)
1084  */
1085 HQUEUE16 WINAPI SetThreadQueue16( DWORD thread, HQUEUE16 hQueue )
1086 {
1087     TEB *teb = thread? THREAD_IdToTEB( thread ) : NtCurrentTeb();
1088     HQUEUE16 oldQueue = teb? teb->queue : 0;
1089
1090     if ( teb )
1091     {
1092         teb->queue = hQueue;
1093
1094         if ( GetTaskQueue16( teb->process->task ) == oldQueue )
1095             SetTaskQueue16( teb->process->task, hQueue );
1096     }
1097
1098     return oldQueue;
1099 }
1100
1101 /***********************************************************************
1102  *           GetThreadQueue  (KERNEL.464)
1103  */
1104 HQUEUE16 WINAPI GetThreadQueue16( DWORD thread )
1105 {
1106     TEB *teb = NULL;
1107     if ( !thread )
1108         teb = NtCurrentTeb();
1109     else if ( HIWORD(thread) )
1110         teb = THREAD_IdToTEB( thread );
1111     else if ( IsTask16( (HTASK16)thread ) )
1112         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1113
1114     return (HQUEUE16)(teb? teb->queue : 0);
1115 }
1116
1117 /***********************************************************************
1118  *           SetFastQueue  (KERNEL.624)
1119  */
1120 VOID WINAPI SetFastQueue16( DWORD thread, HANDLE hQueue )
1121 {
1122     TEB *teb = NULL;
1123     if ( !thread )
1124         teb = NtCurrentTeb();
1125     else if ( HIWORD(thread) )
1126         teb = THREAD_IdToTEB( thread );
1127     else if ( IsTask16( (HTASK16)thread ) )
1128         teb = ((TDB *)GlobalLock16( (HANDLE16)thread ))->teb;
1129
1130     if ( teb ) teb->queue = (HQUEUE16) hQueue;
1131 }
1132
1133 /***********************************************************************
1134  *           GetFastQueue  (KERNEL.625)
1135  */
1136 HANDLE WINAPI GetFastQueue16( void )
1137 {
1138     TEB *teb = NtCurrentTeb();
1139     if (!teb) return 0;
1140
1141     if (!teb->queue)
1142         Callout.InitThreadInput16( 0, THREAD_IsWin16(teb)? 4 : 5 );
1143
1144     if (!teb->queue)
1145         FIXME_(task)("(): should initialize thread-local queue, expect failure!\n" );
1146
1147     return (HANDLE)teb->queue;
1148 }
1149
1150 /***********************************************************************
1151  *           SwitchStackTo   (KERNEL.108)
1152  */
1153 void WINAPI SwitchStackTo16( WORD seg, WORD ptr, WORD top )
1154 {
1155     TDB *pTask;
1156     STACK16FRAME *oldFrame, *newFrame;
1157     INSTANCEDATA *pData;
1158     UINT16 copySize;
1159
1160     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1161     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
1162     TRACE_(task)("old=%04x:%04x new=%04x:%04x\n",
1163                   SELECTOROF( pTask->teb->cur_stack ),
1164                   OFFSETOF( pTask->teb->cur_stack ), seg, ptr );
1165
1166     /* Save the old stack */
1167
1168     oldFrame = THREAD_STACK16( pTask->teb );
1169     /* pop frame + args and push bp */
1170     pData->old_ss_sp   = pTask->teb->cur_stack + sizeof(STACK16FRAME)
1171                            + 2 * sizeof(WORD);
1172     *(WORD *)PTR_SEG_TO_LIN(pData->old_ss_sp) = oldFrame->bp;
1173     pData->stacktop    = top;
1174     pData->stackmin    = ptr;
1175     pData->stackbottom = ptr;
1176
1177     /* Switch to the new stack */
1178
1179     /* Note: we need to take the 3 arguments into account; otherwise,
1180      * the stack will underflow upon return from this function.
1181      */
1182     copySize = oldFrame->bp - OFFSETOF(pData->old_ss_sp);
1183     copySize += 3 * sizeof(WORD) + sizeof(STACK16FRAME);
1184     pTask->teb->cur_stack = PTR_SEG_OFF_TO_SEGPTR( seg, ptr - copySize );
1185     newFrame = THREAD_STACK16( pTask->teb );
1186
1187     /* Copy the stack frame and the local variables to the new stack */
1188
1189     memmove( newFrame, oldFrame, copySize );
1190     newFrame->bp = ptr;
1191     *(WORD *)PTR_SEG_OFF_TO_LIN( seg, ptr ) = 0;  /* clear previous bp */
1192 }
1193
1194
1195 /***********************************************************************
1196  *           SwitchStackBack   (KERNEL.109)
1197  */
1198 void WINAPI SwitchStackBack16( CONTEXT86 *context )
1199 {
1200     STACK16FRAME *oldFrame, *newFrame;
1201     INSTANCEDATA *pData;
1202
1203     if (!(pData = (INSTANCEDATA *)GlobalLock16(SELECTOROF(NtCurrentTeb()->cur_stack))))
1204         return;
1205     if (!pData->old_ss_sp)
1206     {
1207         WARN_(task)("No previous SwitchStackTo\n" );
1208         return;
1209     }
1210     TRACE_(task)("restoring stack %04x:%04x\n",
1211                  SELECTOROF(pData->old_ss_sp), OFFSETOF(pData->old_ss_sp) );
1212
1213     oldFrame = CURRENT_STACK16;
1214
1215     /* Pop bp from the previous stack */
1216
1217     BP_reg(context) = *(WORD *)PTR_SEG_TO_LIN(pData->old_ss_sp);
1218     pData->old_ss_sp += sizeof(WORD);
1219
1220     /* Switch back to the old stack */
1221
1222     NtCurrentTeb()->cur_stack = pData->old_ss_sp - sizeof(STACK16FRAME);
1223     SS_reg(context)  = SELECTOROF(pData->old_ss_sp);
1224     ESP_reg(context) = OFFSETOF(pData->old_ss_sp) - sizeof(DWORD); /*ret addr*/
1225     pData->old_ss_sp = 0;
1226
1227     /* Build a stack frame for the return */
1228
1229     newFrame = CURRENT_STACK16;
1230     newFrame->frame32     = oldFrame->frame32;
1231     newFrame->module_cs   = oldFrame->module_cs;
1232     newFrame->callfrom_ip = oldFrame->callfrom_ip;
1233     newFrame->entry_ip    = oldFrame->entry_ip;
1234 }
1235
1236
1237 /***********************************************************************
1238  *           GetTaskQueueDS16  (KERNEL.118)
1239  */
1240 void WINAPI GetTaskQueueDS16(void)
1241 {
1242     CURRENT_STACK16->ds = GlobalHandleToSel16( GetTaskQueue16(0) );
1243 }
1244
1245
1246 /***********************************************************************
1247  *           GetTaskQueueES16  (KERNEL.119)
1248  */
1249 void WINAPI GetTaskQueueES16(void)
1250 {
1251     CURRENT_STACK16->es = GlobalHandleToSel16( GetTaskQueue16(0) );
1252 }
1253
1254
1255 /***********************************************************************
1256  *           GetCurrentTask   (KERNEL.36)
1257  */
1258 HTASK16 WINAPI GetCurrentTask(void)
1259 {
1260     return PROCESS_Current()->task;
1261 }
1262
1263 DWORD WINAPI WIN16_GetCurrentTask(void)
1264 {
1265     /* This is the version used by relay code; the first task is */
1266     /* returned in the high word of the result */
1267     return MAKELONG( GetCurrentTask(), hFirstTask );
1268 }
1269
1270
1271 /***********************************************************************
1272  *           GetCurrentPDB   (KERNEL.37)
1273  *
1274  * UNDOC: returns PSP of KERNEL in high word
1275  */
1276 DWORD WINAPI GetCurrentPDB16(void)
1277 {
1278     TDB *pTask;
1279
1280     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1281     return MAKELONG(pTask->hPDB, 0); /* FIXME */
1282 }
1283
1284
1285 /***********************************************************************
1286  *           GetCurPID16   (KERNEL.157)
1287  */
1288 DWORD WINAPI GetCurPID16( DWORD unused )
1289 {
1290     return 0;
1291 }
1292
1293
1294 /***********************************************************************
1295  *           GetInstanceData   (KERNEL.54)
1296  */
1297 INT16 WINAPI GetInstanceData16( HINSTANCE16 instance, WORD buffer, INT16 len )
1298 {
1299     char *ptr = (char *)GlobalLock16( instance );
1300     if (!ptr || !len) return 0;
1301     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1302     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1303     return len;
1304 }
1305
1306
1307 /***********************************************************************
1308  *           GetExeVersion   (KERNEL.105)
1309  */
1310 WORD WINAPI GetExeVersion16(void)
1311 {
1312     TDB *pTask;
1313
1314     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1315     return pTask->version;
1316 }
1317
1318
1319 /***********************************************************************
1320  *           SetErrorMode16   (KERNEL.107)
1321  */
1322 UINT16 WINAPI SetErrorMode16( UINT16 mode )
1323 {
1324     TDB *pTask;
1325     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1326     pTask->error_mode = mode;
1327     return SetErrorMode( mode );
1328 }
1329
1330
1331 /***********************************************************************
1332  *           GetDOSEnvironment   (KERNEL.131)
1333  */
1334 SEGPTR WINAPI GetDOSEnvironment16(void)
1335 {
1336     TDB *pTask;
1337
1338     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1339     return PTR_SEG_OFF_TO_SEGPTR( pTask->pdb.environment, 0 );
1340 }
1341
1342
1343 /***********************************************************************
1344  *           GetNumTasks   (KERNEL.152)
1345  */
1346 UINT16 WINAPI GetNumTasks16(void)
1347 {
1348     return nTaskCount;
1349 }
1350
1351
1352 /***********************************************************************
1353  *           GetTaskDS   (KERNEL.155)
1354  *
1355  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1356  * I don't think we need to bother with this.
1357  */
1358 HINSTANCE16 WINAPI GetTaskDS16(void)
1359 {
1360     TDB *pTask;
1361
1362     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1363     return pTask->hInstance;
1364 }
1365
1366 /***********************************************************************
1367  *           GetDummyModuleHandleDS   (KERNEL.602)
1368  */
1369 WORD WINAPI GetDummyModuleHandleDS16(void)
1370 {
1371     TDB *pTask;
1372     WORD selector;
1373
1374     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1375     if (!(pTask->flags & TDBF_WIN32)) return 0;
1376     selector = GlobalHandleToSel16( pTask->hModule );
1377     CURRENT_DS = selector;
1378     return selector;
1379 }
1380
1381 /***********************************************************************
1382  *           IsTask   (KERNEL.320)
1383  */
1384 BOOL16 WINAPI IsTask16( HTASK16 hTask )
1385 {
1386     TDB *pTask;
1387
1388     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1389     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1390     return (pTask->magic == TDB_MAGIC);
1391 }
1392
1393
1394 /***********************************************************************
1395  *           IsWinOldApTask16   (KERNEL.158)
1396  */
1397 BOOL16 WINAPI IsWinOldApTask16( HTASK16 hTask )
1398 {
1399     /* should return bit 0 of byte 0x48 in PSP */
1400     return FALSE;
1401 }
1402
1403 /***********************************************************************
1404  *           SetTaskSignalProc   (KERNEL.38)
1405  *
1406  * Real 16-bit interface is provided by the THUNK_SetTaskSignalProc.
1407  */
1408 FARPROC16 WINAPI SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1409 {
1410     TDB *pTask;
1411     FARPROC16 oldProc;
1412
1413     if (!hTask) hTask = GetCurrentTask();
1414     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return NULL;
1415     oldProc = (FARPROC16)pTask->userhandler;
1416     pTask->userhandler = (USERSIGNALPROC)proc;
1417     return oldProc;
1418 }
1419
1420
1421 /***********************************************************************
1422  *           SetSigHandler   (KERNEL.140)
1423  */
1424 WORD WINAPI SetSigHandler16( FARPROC16 newhandler, FARPROC16* oldhandler,
1425                            UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1426 {
1427     FIXME_(task)("(%p,%p,%p,%d,%d), unimplemented.\n",
1428           newhandler,oldhandler,oldmode,newmode,flag );
1429
1430     if (flag != 1) return 0;
1431     if (!newmode) newhandler = NULL;  /* Default handler */
1432     if (newmode != 4)
1433     {
1434         TDB *pTask;
1435
1436         if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return 0;
1437         if (oldmode) *oldmode = pTask->signal_flags;
1438         pTask->signal_flags = newmode;
1439         if (oldhandler) *oldhandler = pTask->sighandler;
1440         pTask->sighandler = newhandler;
1441     }
1442     return 0;
1443 }
1444
1445
1446 /***********************************************************************
1447  *           GlobalNotify   (KERNEL.154)
1448  *
1449  * Note that GlobalNotify does _not_ return the old NotifyProc
1450  * -- contrary to LocalNotify !!
1451  */
1452 VOID WINAPI GlobalNotify16( FARPROC16 proc )
1453 {
1454     TDB *pTask;
1455
1456     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
1457     pTask->discardhandler = proc;
1458 }
1459
1460
1461 /***********************************************************************
1462  *           GetExePtr   (KERNEL.133)
1463  */
1464 static inline HMODULE16 GetExePtrHelper( HANDLE16 handle, HTASK16 *hTask )
1465 {
1466     char *ptr;
1467     HANDLE16 owner;
1468
1469       /* Check for module handle */
1470
1471     if (!(ptr = GlobalLock16( handle ))) return 0;
1472     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return handle;
1473
1474       /* Search for this handle inside all tasks */
1475
1476     *hTask = hFirstTask;
1477     while (*hTask)
1478     {
1479         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1480         if ((*hTask == handle) ||
1481             (pTask->hInstance == handle) ||
1482             (pTask->hQueue == handle) ||
1483             (pTask->hPDB == handle)) return pTask->hModule;
1484         *hTask = pTask->hNext;
1485     }
1486
1487       /* Check the owner for module handle */
1488
1489     owner = FarGetOwner16( handle );
1490     if (!(ptr = GlobalLock16( owner ))) return 0;
1491     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return owner;
1492
1493       /* Search for the owner inside all tasks */
1494
1495     *hTask = hFirstTask;
1496     while (*hTask)
1497     {
1498         TDB *pTask = (TDB *)GlobalLock16( *hTask );
1499         if ((*hTask == owner) ||
1500             (pTask->hInstance == owner) ||
1501             (pTask->hQueue == owner) ||
1502             (pTask->hPDB == owner)) return pTask->hModule;
1503         *hTask = pTask->hNext;
1504     }
1505
1506     return 0;
1507 }
1508
1509 HMODULE16 WINAPI WIN16_GetExePtr( HANDLE16 handle )
1510 {
1511     HTASK16 hTask = 0;
1512     HMODULE16 hModule = GetExePtrHelper( handle, &hTask );
1513     STACK16FRAME *frame = CURRENT_STACK16;
1514     frame->ecx = hModule;
1515     if (hTask) frame->es = hTask;
1516     return hModule;
1517 }
1518
1519 HMODULE16 WINAPI GetExePtr( HANDLE16 handle )
1520 {
1521     HTASK16 hTask = 0;
1522     return GetExePtrHelper( handle, &hTask );
1523 }
1524
1525
1526 /***********************************************************************
1527  *           TaskFirst   (TOOLHELP.63)
1528  */
1529 BOOL16 WINAPI TaskFirst16( TASKENTRY *lpte )
1530 {
1531     lpte->hNext = hFirstTask;
1532     return TaskNext16( lpte );
1533 }
1534
1535
1536 /***********************************************************************
1537  *           TaskNext   (TOOLHELP.64)
1538  */
1539 BOOL16 WINAPI TaskNext16( TASKENTRY *lpte )
1540 {
1541     TDB *pTask;
1542     INSTANCEDATA *pInstData;
1543
1544     TRACE_(toolhelp)("(%p): task=%04x\n", lpte, lpte->hNext );
1545     if (!lpte->hNext) return FALSE;
1546     pTask = (TDB *)GlobalLock16( lpte->hNext );
1547     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1548     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1549     lpte->hTask         = lpte->hNext;
1550     lpte->hTaskParent   = pTask->hParent;
1551     lpte->hInst         = pTask->hInstance;
1552     lpte->hModule       = pTask->hModule;
1553     lpte->wSS           = SELECTOROF( pTask->teb->cur_stack );
1554     lpte->wSP           = OFFSETOF( pTask->teb->cur_stack );
1555     lpte->wStackTop     = pInstData->stacktop;
1556     lpte->wStackMinimum = pInstData->stackmin;
1557     lpte->wStackBottom  = pInstData->stackbottom;
1558     lpte->wcEvents      = pTask->nEvents;
1559     lpte->hQueue        = pTask->hQueue;
1560     strncpy( lpte->szModule, pTask->module_name, 8 );
1561     lpte->szModule[8]   = '\0';
1562     lpte->wPSPOffset    = 0x100;  /*??*/
1563     lpte->hNext         = pTask->hNext;
1564     return TRUE;
1565 }
1566
1567
1568 /***********************************************************************
1569  *           TaskFindHandle   (TOOLHELP.65)
1570  */
1571 BOOL16 WINAPI TaskFindHandle16( TASKENTRY *lpte, HTASK16 hTask )
1572 {
1573     lpte->hNext = hTask;
1574     return TaskNext16( lpte );
1575 }
1576
1577
1578 /***********************************************************************
1579  *           GetAppCompatFlags16   (KERNEL.354)
1580  */
1581 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1582 {
1583     return GetAppCompatFlags( hTask );
1584 }
1585
1586
1587 /***********************************************************************
1588  *           GetAppCompatFlags32   (USER32.206)
1589  */
1590 DWORD WINAPI GetAppCompatFlags( HTASK hTask )
1591 {
1592     TDB *pTask;
1593
1594     if (!hTask) hTask = GetCurrentTask();
1595     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1596     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1597     return pTask->compat_flags;
1598 }