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     TASK_CallTaskSignalProc( USIG16_TERMINATION, hTask );
 471     PROCESS_CallUserSignalProc( USIG_PROCESS_EXIT, 0 );
 472     PROCESS_CallUserSignalProc( USIG_THREAD_EXIT, 0 );     /* FIXME */
 473     PROCESS_CallUserSignalProc( USIG_PROCESS_DESTROY, 0 );
 474
 475     if (nTaskCount <= 1)
 476     {
 477         TRACE_(task)("this is the last task, exiting\n" );
 478         ExitKernel16();
 479     }
 480
 481     /* FIXME: Hack! Send a message to the initial task so that
 482      * the GetMessage wakes up and the initial task can check whether
 483      * it is the only remaining one and terminate itself ...
 484      * The initial task should probably install hooks or something
 485      * to get informed about task termination :-/
 486      */
 487     Callout.PostAppMessage16( PROCESS_Initial()->task, WM_NULL, 0, 0 );
 488
 489     /* Remove the task from the list to be sure we never switch back to it */
 490     TASK_UnlinkTask( hTask );
 491     if( nTaskCount )
 492     {
 493         TDB* p = (TDB *)GlobalLock16( hFirstTask );
 494         while( p )
 495         {
 496             if( p->hYieldTo == hTask ) p->hYieldTo = 0;
 497             p = (TDB *)GlobalLock16( p->hNext );
 498         }
 499     }
 500
 501     pTask->nEvents = 0;
 502
 503     if ( hLockedTask == hTask )
 504         hLockedTask = 0;
 505
 506     TASK_DeleteTask( hTask );
 507
 508     /* When deleting the current task ... */
 509     if ( hTask == hCurrentTask )
 510     {
 511         DWORD lockCount;
 512
 513         /* ... schedule another one ... */
 514         TASK_Reschedule();
 515
 516         /* ... and completely release the Win16Lock, just in case. */
 517         ReleaseThunkLock( &lockCount );
 518
 519         return;
 520     }
 521
 522     SYSLEVEL_LeaveWin16Lock();
 523 }
 524
 525 /***********************************************************************
 526  *           TASK_Reschedule
 527  *
 528  * This is where all the magic of task-switching happens!
 529  *
 530  * 16-bit Windows performs non-preemptive (cooperative) multitasking.
 531  * This means that each 16-bit task runs until it voluntarily yields
 532  * control, at which point the scheduler gets active and selects the
 533  * next task to run.
 534  *
 535  * In Wine, all processes, even 16-bit ones, are scheduled preemptively
 536  * by the standard scheduler of the underlying OS.  As many 16-bit apps
 537  * *rely* on the behaviour of the Windows scheduler, however, we have
 538  * to simulate that behaviour.
 539  *
 540  * This is achieved as follows: every 16-bit task is at time (except
 541  * during task creation and deletion) in one of two states: either it
 542  * is the one currently running, then the global variable hCurrentTask
 543  * contains its task handle, or it is not currently running, then it
 544  * is blocked on a special scheduler event, a global handle to which
 545  * is stored in the task struct.
 546  *
 547  * When the current task yields control, this routine gets called. Its
 548  * purpose is to determine the next task to be active, signal the
 549  * scheduler event of that task, and then put the current task to sleep
 550  * waiting for *its* scheduler event to get signalled again.
 551  *
 552  * This routine can get called in a few other special situations as well:
 553  *
 554  * - On creation of a 16-bit task, the Unix process executing the task
 555  *   calls TASK_Reschedule once it has completed its initialization.
 556  *   At this point, the task needs to be blocked until its scheduler
 557  *   event is signalled the first time (this will be done by the parent
 558  *   process to get the task up and running).
 559  *
 560  * - When the task currently running terminates itself, this routine gets
 561  *   called and has to schedule another task, *without* blocking the
 562  *   terminating task.
 563  *
 564  * - When a 32-bit thread posts an event for a 16-bit task, it might be
 565  *   the case that *no* 16-bit task is currently running.  In this case
 566  *   the task that has now an event pending is to be scheduled.
 567  *
 568  */
 569 void TASK_Reschedule(void)
 570 {
 571     TDB *pOldTask = NULL, *pNewTask = NULL;
 572     HTASK16 hOldTask = 0, hNewTask = 0;
 573     enum { MODE_YIELD, MODE_SLEEP, MODE_WAKEUP } mode;
 574     DWORD lockCount;
 575
 576     SYSLEVEL_EnterWin16Lock();
 577
 578     /* Check what we need to do */
 579     hOldTask = GetCurrentTask();
 580     pOldTask = (TDB *)GlobalLock16( hOldTask );
 581     TRACE_(task)( "entered with hCurrentTask %04x by hTask %04x (pid %ld)\n",
 582                   hCurrentTask, hOldTask, (long) getpid() );
 583
 584     if ( pOldTask && THREAD_IsWin16( NtCurrentTeb() ) )
 585     {
 586         /* We are called by an active (non-deleted) 16-bit task */
 587
 588         /* If we don't even have a current task, or else the current
 589            task has yielded, we'll need to schedule a new task and
 590            (possibly) put the calling task to sleep.  Otherwise, we
 591            only block the caller. */
 592
 593         if ( !hCurrentTask || hCurrentTask == hOldTask )
 594             mode = MODE_YIELD;
 595         else
 596             mode = MODE_SLEEP;
 597     }
 598     else
 599     {
 600         /* We are called by a deleted 16-bit task or a 32-bit thread */
 601
 602         /* The only situation where we need to do something is if we
 603            now do not have a current task.  Then, we'll need to wake up
 604            some task that has events pending. */
 605
 606         if ( !hCurrentTask || hCurrentTask == hOldTask )
 607             mode = MODE_WAKEUP;
 608         else
 609         {
 610             /* nothing to do */
 611             SYSLEVEL_LeaveWin16Lock();
 612             return;
 613         }
 614     }
 615
 616     /* Find a task to yield to: check for DirectedYield() */
 617     if ( mode == MODE_YIELD && pOldTask && pOldTask->hYieldTo )
 618     {
 619         hNewTask = pOldTask->hYieldTo;
 620         pNewTask = (TDB *)GlobalLock16( hNewTask );
 621         if( !pNewTask || !pNewTask->nEvents) hNewTask = 0;
 622         pOldTask->hYieldTo = 0;
 623     }
 624
 625     /* Find a task to yield to: check for pending events */
 626     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && !hNewTask )
 627     {
 628         hNewTask = hFirstTask;
 629         while (hNewTask)
 630         {
 631             pNewTask = (TDB *)GlobalLock16( hNewTask );
 632
 633             TRACE_(task)( "\ttask = %04x, events = %i\n",
 634                           hNewTask, pNewTask->nEvents );
 635
 636             if (pNewTask->nEvents) break;
 637             hNewTask = pNewTask->hNext;
 638         }
 639         if (hLockedTask && (hNewTask != hLockedTask)) hNewTask = 0;
 640     }
 641
 642     /* If we are still the task with highest priority, just return ... */
 643     if ( mode == MODE_YIELD && hNewTask == hCurrentTask )
 644     {
 645         TRACE_(task)("returning to the current task (%04x)\n", hCurrentTask );
 646         SYSLEVEL_LeaveWin16Lock();
 647
 648         /* Allow Win32 threads to thunk down even while a Win16 task is
 649            in a tight PeekMessage() or Yield() loop ... */
 650         ReleaseThunkLock( &lockCount );
 651         RestoreThunkLock( lockCount );
 652         return;
 653     }
 654
 655     /* If no task to yield to found, suspend 16-bit scheduler ... */
 656     if ( mode == MODE_YIELD && !hNewTask )
 657     {
 658         TRACE_(task)("No currently active task\n");
 659         hCurrentTask = 0;
 660     }
 661
 662     /* If we found a task to wake up, do it ... */
 663     if ( (mode == MODE_YIELD || mode == MODE_WAKEUP) && hNewTask )
 664     {
 665         TRACE_(task)("Switching to task %04x (%.8s)\n",
 666                       hNewTask, pNewTask->module_name );
 667
 668         pNewTask->priority++;
 669         TASK_UnlinkTask( hNewTask );
 670         TASK_LinkTask( hNewTask );
 671         pNewTask->priority--;
 672
 673         hCurrentTask = hNewTask;
 674         SetEvent( pNewTask->hEvent );
 675
 676         /* This is set just in case some app reads it ... */
 677         pNewTask->ss_sp = pNewTask->teb->cur_stack;
 678     }
 679
 680     /* If we need to put the current task to sleep, do it ... */
 681     if ( (mode == MODE_YIELD || mode == MODE_SLEEP) && hOldTask != hCurrentTask )
 682     {
 683         ResetEvent( pOldTask->hEvent );
 684
 685         ReleaseThunkLock( &lockCount );
 686         SYSLEVEL_CheckNotLevel( 1 );
 687         WaitForSingleObject( pOldTask->hEvent, INFINITE );
 688         RestoreThunkLock( lockCount );
 689     }
 690
 691     SYSLEVEL_LeaveWin16Lock();
 692 }
 693
 694 /***********************************************************************
 695  *           InitTask  (KERNEL.91)
 696  *
 697  * Called by the application startup code.
 698  */
 699 void WINAPI InitTask16( CONTEXT86 *context )
 700 {
 701     TDB *pTask;
 702     INSTANCEDATA *pinstance;
 703     SEGPTR ptr;
 704
 705     EAX_reg(context) = 0;
 706     if (!(pTask = (TDB *)GlobalLock16( GetCurrentTask() ))) return;
 707
 708     /* Note: we need to trust that BX/CX contain the stack/heap sizes,
 709        as some apps, notably Visual Basic apps, *modify* the heap/stack
 710        size of the instance data segment before calling InitTask() */
 711
 712     /* Initialize the INSTANCEDATA structure */
 713     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 714     pinstance->stackmin    = OFFSETOF( pTask->teb->cur_stack );
 715     pinstance->stackbottom = pinstance->stackmin; /* yup, that's right. Confused me too. */
 716     pinstance->stacktop    = ( pinstance->stackmin > BX_reg(context)?
 717                                pinstance->stackmin - BX_reg(context) : 0 ) + 150;
 718
 719     /* Initialize the local heap */
 720     if ( CX_reg(context) )
 721         LocalInit16( pTask->hInstance, 0, CX_reg(context) );
 722
 723     /* Initialize implicitly loaded DLLs */
 724     NE_InitializeDLLs( pTask->hModule );
 725
 726     /* Registers on return are:
 727      * ax     1 if OK, 0 on error
 728      * cx     stack limit in bytes
 729      * dx     cmdShow parameter
 730      * si     instance handle of the previous instance
 731      * di     instance handle of the new task
 732      * es:bx  pointer to command-line inside PSP
 733      *
 734      * 0 (=%bp) is pushed on the stack
 735      */
 736     ptr = stack16_push( sizeof(WORD) );
 737     *(WORD *)PTR_SEG_TO_LIN(ptr) = 0;
 738     ESP_reg(context) -= 2;
 739
 740     EAX_reg(context) = 1;
 741
 742     if (!pTask->pdb.cmdLine[0]) EBX_reg(context) = 0x80;
 743     else
 744     {
 745         LPBYTE p = &pTask->pdb.cmdLine[1];
 746         while ((*p == ' ') || (*p == '\t')) p++;
 747         EBX_reg(context) = 0x80 + (p - pTask->pdb.cmdLine);
 748     }
 749     ECX_reg(context) = pinstance->stacktop;
 750     EDX_reg(context) = pTask->nCmdShow;
 751     ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 752     EDI_reg(context) = (DWORD)pTask->hInstance;
 753     ES_reg (context) = (WORD)pTask->hPDB;
 754 }
 755
 756
 757 /***********************************************************************
 758  *           WaitEvent  (KERNEL.30)
 759  */
 760 BOOL16 WINAPI WaitEvent16( HTASK16 hTask )
 761 {
 762     TDB *pTask;
 763
 764     if (!hTask) hTask = GetCurrentTask();
 765     pTask = (TDB *)GlobalLock16( hTask );
 766
 767     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 768     {
 769         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 770         return TRUE;
 771     }
 772
 773     if (pTask->nEvents > 0)
 774     {
 775         pTask->nEvents--;
 776         return FALSE;
 777     }
 778     TASK_Reschedule();
 779
 780     /* When we get back here, we have an event */
 781
 782     if (pTask->nEvents > 0) pTask->nEvents--;
 783     return TRUE;
 784 }
 785
 786
 787 /***********************************************************************
 788  *           PostEvent  (KERNEL.31)
 789  */
 790 void WINAPI PostEvent16( HTASK16 hTask )
 791 {
 792     TDB *pTask;
 793
 794     if (!hTask) hTask = GetCurrentTask();
 795     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 796
 797     if ( !THREAD_IsWin16( pTask->teb ) )
 798     {
 799         FIXME_(task)("called for Win32 thread (%04x)!\n", pTask->teb->teb_sel );
 800         return;
 801     }
 802
 803     pTask->nEvents++;
 804
 805     /* If we are a 32-bit task, we might need to wake up the 16-bit scheduler */
 806     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 807         TASK_Reschedule();
 808 }
 809
 810
 811 /***********************************************************************
 812  *           SetPriority  (KERNEL.32)
 813  */
 814 void WINAPI SetPriority16( HTASK16 hTask, INT16 delta )
 815 {
 816     TDB *pTask;
 817     INT16 newpriority;
 818
 819     if (!hTask) hTask = GetCurrentTask();
 820     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 821     newpriority = pTask->priority + delta;
 822     if (newpriority < -32) newpriority = -32;
 823     else if (newpriority > 15) newpriority = 15;
 824
 825     pTask->priority = newpriority + 1;
 826     TASK_UnlinkTask( hTask );
 827     TASK_LinkTask( hTask );
 828     pTask->priority--;
 829 }
 830
 831
 832 /***********************************************************************
 833  *           LockCurrentTask  (KERNEL.33)
 834  */
 835 HTASK16 WINAPI LockCurrentTask16( BOOL16 bLock )
 836 {
 837     if (bLock) hLockedTask = GetCurrentTask();
 838     else hLockedTask = 0;
 839     return hLockedTask;
 840 }
 841
 842
 843 /***********************************************************************
 844  *           IsTaskLocked  (KERNEL.122)
 845  */
 846 HTASK16 WINAPI IsTaskLocked16(void)
 847 {
 848     return hLockedTask;
 849 }
 850
 851
 852 /***********************************************************************
 853  *           OldYield  (KERNEL.117)
 854  */
 855 void WINAPI OldYield16(void)
 856 {
 857     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 858
 859     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 860     {
 861         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 862         return;
 863     }
 864
 865     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 866     TASK_Reschedule();
 867     if (pCurTask) pCurTask->nEvents--;
 868 }
 869
 870 /***********************************************************************
 871  *           WIN32_OldYield16  (KERNEL.447)
 872  */
 873 void WINAPI WIN32_OldYield16(void)
 874 {
 875    DWORD count;
 876
 877    ReleaseThunkLock(&count);
 878    RestoreThunkLock(count);
 879 }
 880
 881 /***********************************************************************
 882  *           DirectedYield  (KERNEL.150)
 883  */
 884 void WINAPI DirectedYield16( HTASK16 hTask )
 885 {
 886     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 887
 888     if ( !THREAD_IsWin16( NtCurrentTeb() ) )
 889     {
 890         FIXME_(task)("called for Win32 thread (%04x)!\n", NtCurrentTeb()->teb_sel);
 891         return;
 892     }
 893
 894     TRACE_(task)("%04x: DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 895
 896     pCurTask->hYieldTo = hTask;
 897     OldYield16();
 898
 899     TRACE_(task)("%04x: back from DirectedYield(%04x)\n", pCurTask->hSelf, hTask );
 900 }
 901
 902 /***********************************************************************
 903  *           Yield16  (KERNEL.29)
 904  */
 905 void WINAPI Yield16(void)
 906 {
 907     TDB *pCurTask = (TDB *)GlobalLock16( GetCurrentTask() );
 908
 909     if (pCurTask) pCurTask->hYieldTo = 0;
 910     if (pCurTask && pCurTask->hQueue) Callout.UserYield16();
 911     else OldYield16();
 912 }
 913
 914 /***********************************************************************
 915  *           KERNEL_490  (KERNEL.490)
 916  */
 917 HTASK16 WINAPI KERNEL_490( HTASK16 someTask )
 918 {
 919     if ( !someTask ) return 0;
 920
 921     FIXME_(task)("(%04x): stub\n", someTask );
 922     return 0;
 923 }
 924
 925 /***********************************************************************
 926  *           MakeProcInstance16  (KERNEL.51)
 927  */
 928 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 929 {
 930     BYTE *thunk,*lfunc;
 931     SEGPTR thunkaddr;
 932
 933     if (!func) {
 934       ERR_(task)("Ouch ! MakeProcInstance called with func == NULL !\n");
 935       return (FARPROC16)0; /* Windows seems to do the same */
 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_(task)("(%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_(task)("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_(task)("(%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_(task)("(): 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_(task)("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_(task)("No previous SwitchStackTo\n" );
1250         return;
1251     }
1252     TRACE_(task)("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_(task)("(%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     strncpy( lpte->szModule, pTask->module_name, 8 );
1616     lpte->szModule[8]   = '\0';
1617     lpte->wPSPOffset    = 0x100;  /*??*/
1618     lpte->hNext         = pTask->hNext;
1619     return TRUE;
1620 }
1621
1622
1623 /***********************************************************************
1624  *           TaskFindHandle   (TOOLHELP.65)
1625  */
1626 BOOL16 WINAPI TaskFindHandle16( TASKENTRY *lpte, HTASK16 hTask )
1627 {
1628     lpte->hNext = hTask;
1629     return TaskNext16( lpte );
1630 }
1631
1632
1633 /***********************************************************************
1634  *           GetAppCompatFlags16   (KERNEL.354)
1635  */
1636 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1637 {
1638     return GetAppCompatFlags( hTask );
1639 }
1640
1641
1642 /***********************************************************************
1643  *           GetAppCompatFlags32   (USER32.206)
1644  */
1645 DWORD WINAPI GetAppCompatFlags( HTASK hTask )
1646 {
1647     TDB *pTask;
1648
1649     if (!hTask) hTask = GetCurrentTask();
1650     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1651     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1652     return pTask->compat_flags;
1653 }