loader/task.c

   1 /*
   2  * Task functions
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10
  11 #include "windows.h"
  12 #include "user.h"
  13 #include "callback.h"
  14 #include "drive.h"
  15 #include "file.h"
  16 #include "global.h"
  17 #include "instance.h"
  18 #include "message.h"
  19 #include "miscemu.h"
  20 #include "module.h"
  21 #include "neexe.h"
  22 #include "peexe.h"
  23 #include "pe_image.h"
  24 #include "process.h"
  25 #include "queue.h"
  26 #include "selectors.h"
  27 #include "stackframe.h"
  28 #include "task.h"
  29 #include "thread.h"
  30 #include "toolhelp.h"
  31 #include "winnt.h"
  32 #include "thread.h"
  33 #include "debug.h"
  34 #include "dde_proc.h"
  35
  36   /* Min. number of thunks allocated when creating a new segment */
  37 #define MIN_THUNKS  32
  38
  39 extern INT32 WINSOCK_DeleteTaskWSI( TDB* pTask, struct _WSINFO* );
  40 extern BOOL32 MODULE_FreeModule( HMODULE16 hModule, TDB* ptaskContext );
  41
  42   /* Pointer to function to switch to a larger stack */
  43 int (*IF1632_CallLargeStack)( int (*func)(), void *arg ) = NULL;
  44
  45 static HTASK16 hFirstTask = 0;
  46 static HTASK16 hCurrentTask = 0;
  47 static HTASK16 hTaskToKill = 0;
  48 static HTASK16 hLockedTask = 0;
  49 static UINT16 nTaskCount = 0;
  50
  51 static void TASK_YieldToSystem(TDB*);
  52
  53
  54 /***********************************************************************
  55  *           TASK_GetNextTask
  56  */
  57 HTASK16 TASK_GetNextTask( HTASK16 hTask )
  58 {
  59     TDB* pTask = (TDB*)GlobalLock16(hTask);
  60
  61     if (pTask->hNext) return pTask->hNext;
  62     return (hFirstTask != hTask) ? hFirstTask : 0;
  63 }
  64
  65
  66 /***********************************************************************
  67  *           TASK_LinkTask
  68  */
  69 static void TASK_LinkTask( HTASK16 hTask )
  70 {
  71     HTASK16 *prevTask;
  72     TDB *pTask;
  73
  74     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
  75     prevTask = &hFirstTask;
  76     while (*prevTask)
  77     {
  78         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
  79         if (prevTaskPtr->priority >= pTask->priority) break;
  80         prevTask = &prevTaskPtr->hNext;
  81     }
  82     pTask->hNext = *prevTask;
  83     *prevTask = hTask;
  84     nTaskCount++;
  85 }
  86
  87
  88 /***********************************************************************
  89  *           TASK_UnlinkTask
  90  */
  91 static void TASK_UnlinkTask( HTASK16 hTask )
  92 {
  93     HTASK16 *prevTask;
  94     TDB *pTask;
  95
  96     prevTask = &hFirstTask;
  97     while (*prevTask && (*prevTask != hTask))
  98     {
  99         pTask = (TDB *)GlobalLock16( *prevTask );
 100         prevTask = &pTask->hNext;
 101     }
 102     if (*prevTask)
 103     {
 104         pTask = (TDB *)GlobalLock16( *prevTask );
 105         *prevTask = pTask->hNext;
 106         pTask->hNext = 0;
 107         nTaskCount--;
 108     }
 109 }
 110
 111
 112 /***********************************************************************
 113  *           TASK_CreateThunks
 114  *
 115  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 116  * and containing 'count' entries.
 117  */
 118 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 119 {
 120     int i;
 121     WORD free;
 122     THUNKS *pThunk;
 123
 124     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 125     pThunk->next = 0;
 126     pThunk->magic = THUNK_MAGIC;
 127     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 128     free = pThunk->free;
 129     for (i = 0; i < count-1; i++)
 130     {
 131         free += 8;  /* Offset of next thunk */
 132         pThunk->thunks[4*i] = free;
 133     }
 134     pThunk->thunks[4*i] = 0;  /* Last thunk */
 135 }
 136
 137
 138 /***********************************************************************
 139  *           TASK_AllocThunk
 140  *
 141  * Allocate a thunk for MakeProcInstance().
 142  */
 143 static SEGPTR TASK_AllocThunk( HTASK16 hTask )
 144 {
 145     TDB *pTask;
 146     THUNKS *pThunk;
 147     WORD sel, base;
 148
 149     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 150     sel = pTask->hCSAlias;
 151     pThunk = &pTask->thunks;
 152     base = (int)pThunk - (int)pTask;
 153     while (!pThunk->free)
 154     {
 155         sel = pThunk->next;
 156         if (!sel)  /* Allocate a new segment */
 157         {
 158             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 159                                 pTask->hPDB, TRUE, FALSE, FALSE );
 160             if (!sel) return (SEGPTR)0;
 161             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 162             pThunk->next = sel;
 163         }
 164         pThunk = (THUNKS *)GlobalLock16( sel );
 165         base = 0;
 166     }
 167     base += pThunk->free;
 168     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 169     return PTR_SEG_OFF_TO_SEGPTR( sel, base );
 170 }
 171
 172
 173 /***********************************************************************
 174  *           TASK_FreeThunk
 175  *
 176  * Free a MakeProcInstance() thunk.
 177  */
 178 static BOOL32 TASK_FreeThunk( HTASK16 hTask, SEGPTR thunk )
 179 {
 180     TDB *pTask;
 181     THUNKS *pThunk;
 182     WORD sel, base;
 183
 184     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 185     sel = pTask->hCSAlias;
 186     pThunk = &pTask->thunks;
 187     base = (int)pThunk - (int)pTask;
 188     while (sel && (sel != HIWORD(thunk)))
 189     {
 190         sel = pThunk->next;
 191         pThunk = (THUNKS *)GlobalLock16( sel );
 192         base = 0;
 193     }
 194     if (!sel) return FALSE;
 195     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 196     pThunk->free = LOWORD(thunk) - base;
 197     return TRUE;
 198 }
 199
 200
 201 /***********************************************************************
 202  *           TASK_CallToStart
 203  *
 204  * 32-bit entry point for a new task. This function is responsible for
 205  * setting up the registers and jumping to the 16-bit entry point.
 206  */
 207 static void TASK_CallToStart(void)
 208 {
 209     int exit_code = 1;
 210     TDB *pTask = (TDB *)GlobalLock16( hCurrentTask );
 211     NE_MODULE *pModule = MODULE_GetPtr( pTask->hModule );
 212     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 213
 214     SET_CUR_THREAD( pTask->thdb );
 215     /* Terminate the stack frame */
 216     THREAD_STACK16(pTask->thdb)->frame32 = NULL;
 217     if (pModule->flags & NE_FFLAGS_WIN32)
 218     {
 219         /* FIXME: all this is an ugly hack */
 220
 221         FARPROC32 entry = (FARPROC32)RVA_PTR( PROCESS_Current()->exe_modref->module, OptionalHeader.AddressOfEntryPoint );
 222
 223         pTask->userhandler = (USERSIGNALPROC)&USER_SignalProc;
 224         if (pModule->heap_size)
 225             LocalInit( pTask->hInstance, 0, pModule->heap_size );
 226
 227         InitApp( pTask->hModule );
 228         PE_InitializeDLLs( PROCESS_Current(), DLL_PROCESS_ATTACH, (LPVOID)-1 );
 229         TRACE(relay, "(entryproc=%p)\n", entry );
 230         exit_code = entry();
 231         TASK_KillCurrentTask( exit_code );
 232     }
 233     else
 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         CONTEXT context;
 248
 249         memset( &context, 0, sizeof(context) );
 250         CS_reg(&context)  = pSegTable[pModule->cs - 1].selector;
 251         DS_reg(&context)  = pSegTable[pModule->dgroup - 1].selector;
 252         ES_reg(&context)  = pTask->hPDB;
 253         EIP_reg(&context) = pModule->ip;
 254         EBX_reg(&context) = pModule->stack_size;
 255         ECX_reg(&context) = pModule->heap_size;
 256         EDI_reg(&context) = context.SegDs;
 257
 258         TRACE(task, "Starting main program: cs:ip=%04lx:%04x ds=%04lx ss:sp=%04x:%04x\n",
 259                       CS_reg(&context), IP_reg(&context), DS_reg(&context),
 260                       SELECTOROF(pTask->thdb->cur_stack),
 261                       OFFSETOF(pTask->thdb->cur_stack) );
 262
 263         Callbacks->CallRegisterShortProc( &context, 0 );
 264         /* This should never return */
 265         fprintf( stderr, "TASK_CallToStart: Main program returned!\n" );
 266         TASK_KillCurrentTask( 1 );
 267     }
 268 }
 269
 270
 271 /***********************************************************************
 272  *           TASK_Create
 273  */
 274 HTASK16 TASK_Create( THDB *thdb, NE_MODULE *pModule, HINSTANCE16 hInstance,
 275                      HINSTANCE16 hPrevInstance, UINT16 cmdShow)
 276 {
 277     HTASK16 hTask;
 278     TDB *pTask;
 279     LPSTR name, cmd_line;
 280     WORD sp;
 281     char *stack32Top;
 282     STACK16FRAME *frame16;
 283     STACK32FRAME *frame32;
 284     PDB32 *pdb32 = thdb->process;
 285     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 286
 287       /* Allocate the task structure */
 288
 289     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 290                           pModule->self, FALSE, FALSE, FALSE );
 291     if (!hTask) return 0;
 292     pTask = (TDB *)GlobalLock16( hTask );
 293
 294     /* Fill the task structure */
 295
 296     pTask->nEvents       = 1;  /* So the task can be started */
 297     pTask->hSelf         = hTask;
 298     pTask->flags         = 0;
 299
 300     if (pModule->flags & NE_FFLAGS_WIN32)
 301         pTask->flags    |= TDBF_WIN32;
 302
 303     pTask->version       = pModule->expected_version;
 304     pTask->hInstance     = hInstance;
 305     pTask->hPrevInstance = hPrevInstance;
 306     pTask->hModule       = pModule->self;
 307     pTask->hParent       = hCurrentTask;
 308     pTask->magic         = TDB_MAGIC;
 309     pTask->nCmdShow      = cmdShow;
 310     pTask->thdb          = thdb;
 311     pTask->curdrive      = DRIVE_GetCurrentDrive() | 0x80;
 312     strcpy( pTask->curdir, "\\" );
 313     lstrcpyn32A( pTask->curdir + 1, DRIVE_GetDosCwd( DRIVE_GetCurrentDrive() ),
 314                  sizeof(pTask->curdir) - 1 );
 315
 316       /* Create the thunks block */
 317
 318     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 319
 320       /* Copy the module name */
 321
 322     name = MODULE_GetModuleName( pModule->self );
 323     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 324
 325       /* Allocate a selector for the PDB */
 326
 327     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB),
 328                                     pModule->self, FALSE, FALSE, FALSE, NULL );
 329
 330       /* Fill the PDB */
 331
 332     pTask->pdb.int20 = 0x20cd;
 333     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 334     PUT_DWORD(&pTask->pdb.dispatcher[1], (DWORD)MODULE_GetEntryPoint(
 335            GetModuleHandle16("KERNEL"), 102 ));  /* KERNEL.102 is DOS3Call() */
 336     pTask->pdb.savedint22 = INT_GetHandler( 0x22 );
 337     pTask->pdb.savedint23 = INT_GetHandler( 0x23 );
 338     pTask->pdb.savedint24 = INT_GetHandler( 0x24 );
 339     pTask->pdb.fileHandlesPtr =
 340         PTR_SEG_OFF_TO_SEGPTR( GlobalHandleToSel(pTask->hPDB),
 341                                (int)&((PDB *)0)->fileHandles );
 342     pTask->pdb.hFileHandles = 0;
 343     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 344     pTask->pdb.environment    = pdb32->env_db->env_sel;
 345     pTask->pdb.nbFiles        = 20;
 346
 347     /* Fill the command line */
 348
 349     cmd_line = pdb32->env_db->cmd_line;
 350     while (*cmd_line && (*cmd_line != ' ') && (*cmd_line != '\t')) cmd_line++;
 351     lstrcpyn32A( pTask->pdb.cmdLine+1, cmd_line, sizeof(pTask->pdb.cmdLine)-1);
 352     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 353
 354       /* Get the compatibility flags */
 355
 356     pTask->compat_flags = GetProfileInt32A( "Compatibility", name, 0 );
 357
 358       /* Allocate a code segment alias for the TDB */
 359
 360     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 361                                           sizeof(TDB), pTask->hPDB, TRUE,
 362                                           FALSE, FALSE, NULL );
 363
 364       /* Set the owner of the environment block */
 365
 366     FarSetOwner( pTask->pdb.environment, pTask->hPDB );
 367
 368       /* Default DTA overwrites command-line */
 369
 370     pTask->dta = PTR_SEG_OFF_TO_SEGPTR( pTask->hPDB,
 371                                 (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 372
 373     /* Create the 16-bit stack frame */
 374
 375     if (!(sp = pModule->sp))
 376         sp = pSegTable[pModule->ss-1].minsize + pModule->stack_size;
 377     sp &= ~1;
 378     pTask->thdb->cur_stack = PTR_SEG_OFF_TO_SEGPTR( pTask->hInstance, sp );
 379     pTask->thdb->cur_stack -= sizeof(STACK16FRAME) + sizeof(STACK32FRAME *);
 380     frame16 = (STACK16FRAME *)PTR_SEG_TO_LIN( pTask->thdb->cur_stack );
 381     frame16->ebp = sp + (int)&((STACK16FRAME *)0)->bp;
 382     frame16->bp = LOWORD(frame16->ebp);
 383     frame16->ds = frame16->es = pTask->hInstance;
 384     frame16->entry_point = 0;
 385     frame16->entry_cs = 0;
 386     /* The remaining fields will be initialized in TASK_Reschedule */
 387
 388     /* Create the 32-bit stack frame */
 389
 390     stack32Top = (char*)pTask->thdb->teb.stack_top;
 391     frame16->frame32 = frame32 = (STACK32FRAME *)stack32Top - 1;
 392     frame32->frame16 = pTask->thdb->cur_stack + sizeof(STACK16FRAME);
 393     frame32->edi     = 0;
 394     frame32->esi     = 0;
 395     frame32->edx     = 0;
 396     frame32->ecx     = 0;
 397     frame32->ebx     = 0;
 398     frame32->retaddr = (DWORD)TASK_CallToStart;
 399     /* The remaining fields will be initialized in TASK_Reschedule */
 400
 401     if (!THREAD_Current()->cur_stack)
 402         THREAD_Current()->cur_stack = pTask->thdb->cur_stack;
 403
 404     /* Add the task to the linked list */
 405
 406     TASK_LinkTask( hTask );
 407
 408     TRACE(task, "module='%s' cmdline='%s' task=%04x\n",
 409           name, cmd_line, hTask );
 410
 411     return hTask;
 412 }
 413
 414
 415 /***********************************************************************
 416  *           TASK_DeleteTask
 417  */
 418 static void TASK_DeleteTask( HTASK16 hTask )
 419 {
 420     TDB *pTask;
 421     HGLOBAL16 hPDB;
 422
 423     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 424     hPDB = pTask->hPDB;
 425
 426     pTask->magic = 0xdead; /* invalidate signature */
 427
 428     /* Delete the Win32 part of the task */
 429
 430     K32OBJ_DecCount( &pTask->thdb->process->header );
 431     K32OBJ_DecCount( &pTask->thdb->header );
 432
 433     /* Free the task module */
 434
 435     MODULE_FreeModule( pTask->hModule, pTask );
 436
 437     /* Free the selector aliases */
 438
 439     GLOBAL_FreeBlock( pTask->hCSAlias );
 440     GLOBAL_FreeBlock( pTask->hPDB );
 441
 442     /* Free the task structure itself */
 443
 444     GlobalFree16( hTask );
 445
 446     /* Free all memory used by this task (including the 32-bit stack, */
 447     /* the environment block and the thunk segments). */
 448
 449     GlobalFreeAll( hPDB );
 450 }
 451
 452
 453 /***********************************************************************
 454  *           TASK_KillCurrentTask
 455  *
 456  * Kill the currently running task. As it's not possible to kill the
 457  * current task like this, it is simply marked for destruction, and will
 458  * be killed when either TASK_Reschedule or this function is called again
 459  * in the context of another task.
 460  */
 461 void TASK_KillCurrentTask( INT16 exitCode )
 462 {
 463     TDB* pTask = (TDB*) GlobalLock16( hCurrentTask );
 464     if (!pTask) USER_ExitWindows();  /* No current task yet */
 465
 466     TRACE(task, "Killing task %04x\n", hCurrentTask );
 467
 468     /* Delete active sockets */
 469
 470     if( pTask->pwsi )
 471         WINSOCK_DeleteTaskWSI( pTask, pTask->pwsi );
 472
 473     /* Perform USER cleanup */
 474
 475     if (pTask->userhandler)
 476         pTask->userhandler( hCurrentTask, USIG_TERMINATION, 0,
 477                             pTask->hInstance, pTask->hQueue );
 478
 479     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 480     {
 481         /* If another task is already marked for destruction, */
 482         /* we can kill it now, as we are in another context.  */
 483         TASK_DeleteTask( hTaskToKill );
 484     }
 485
 486     if (nTaskCount <= 1)
 487     {
 488         TRACE(task, "this is the last task, exiting\n" );
 489         USER_ExitWindows();
 490     }
 491
 492     /* Remove the task from the list to be sure we never switch back to it */
 493     TASK_UnlinkTask( hCurrentTask );
 494     if( nTaskCount )
 495     {
 496         TDB* p = (TDB *)GlobalLock16( hFirstTask );
 497         while( p )
 498         {
 499             if( p->hYieldTo == hCurrentTask ) p->hYieldTo = 0;
 500             p = (TDB *)GlobalLock16( p->hNext );
 501         }
 502     }
 503
 504     hTaskToKill = hCurrentTask;
 505     hLockedTask = 0;
 506
 507     pTask->nEvents = 0;
 508     TASK_YieldToSystem(pTask);
 509
 510     /* We should never return from this Yield() */
 511
 512     fprintf(stderr,"Return of the living dead %04x!!!\n", hCurrentTask);
 513     exit(1);
 514 }
 515
 516 /***********************************************************************
 517  *           TASK_Reschedule
 518  *
 519  * This is where all the magic of task-switching happens!
 520  *
 521  * Note: This function should only be called via the TASK_YieldToSystem()
 522  *       wrapper, to make sure that all the context is saved correctly.
 523  *
 524  *       It must not call functions that may yield control.
 525  */
 526 void TASK_Reschedule(void)
 527 {
 528     TDB *pOldTask = NULL, *pNewTask;
 529     HTASK16 hTask = 0;
 530     STACK16FRAME *newframe16;
 531
 532 #ifdef CONFIG_IPC
 533     dde_reschedule();
 534 #endif
 535       /* First check if there's a task to kill */
 536
 537     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 538     {
 539         TASK_DeleteTask( hTaskToKill );
 540         hTaskToKill = 0;
 541     }
 542
 543     /* Find a task to yield to */
 544
 545     pOldTask = (TDB *)GlobalLock16( hCurrentTask );
 546     if (pOldTask && pOldTask->hYieldTo)
 547     {
 548         /* check for DirectedYield() */
 549
 550         hTask = pOldTask->hYieldTo;
 551         pNewTask = (TDB *)GlobalLock16( hTask );
 552         if( !pNewTask || !pNewTask->nEvents) hTask = 0;
 553         pOldTask->hYieldTo = 0;
 554     }
 555
 556     /* extract hardware events only! */
 557
 558     if (!hTask) EVENT_WaitNetEvent( FALSE, TRUE );
 559
 560     while (!hTask)
 561     {
 562         /* Find a task that has an event pending */
 563
 564         hTask = hFirstTask;
 565         while (hTask)
 566         {
 567             pNewTask = (TDB *)GlobalLock16( hTask );
 568
 569             TRACE(task, "\ttask = %04x, events = %i\n", hTask, pNewTask->nEvents);
 570
 571             if (pNewTask->nEvents) break;
 572             hTask = pNewTask->hNext;
 573         }
 574         if (hLockedTask && (hTask != hLockedTask)) hTask = 0;
 575         if (hTask) break;
 576
 577         /* No task found, wait for some events to come in */
 578
 579         EVENT_WaitNetEvent( TRUE, TRUE );
 580     }
 581
 582     if (hTask == hCurrentTask)
 583     {
 584        TRACE(task, "returning to the current task(%04x)\n", hTask );
 585        return;  /* Nothing to do */
 586     }
 587     pNewTask = (TDB *)GlobalLock16( hTask );
 588     TRACE(task, "Switching to task %04x (%.8s)\n",
 589                   hTask, pNewTask->module_name );
 590
 591      /* Make the task the last in the linked list (round-robin scheduling) */
 592
 593     pNewTask->priority++;
 594     TASK_UnlinkTask( hTask );
 595     TASK_LinkTask( hTask );
 596     pNewTask->priority--;
 597
 598     /* Finish initializing the new task stack if necessary */
 599
 600     newframe16 = THREAD_STACK16( pNewTask->thdb );
 601     if (!newframe16->entry_cs)
 602     {
 603         STACK16FRAME *oldframe16 = CURRENT_STACK16;
 604         STACK32FRAME *oldframe32 = oldframe16->frame32;
 605         STACK32FRAME *newframe32 = newframe16->frame32;
 606         newframe16->entry_ip     = oldframe16->entry_ip;
 607         newframe16->entry_cs     = oldframe16->entry_cs;
 608         newframe16->ip           = oldframe16->ip;
 609         newframe16->cs           = oldframe16->cs;
 610         newframe32->ebp          = oldframe32->ebp;
 611         newframe32->restore_addr = oldframe32->restore_addr;
 612         newframe32->codeselector = oldframe32->codeselector;
 613     }
 614
 615     /* Switch to the new stack */
 616
 617     hCurrentTask = hTask;
 618     SET_CUR_THREAD( pNewTask->thdb );
 619     pNewTask->ss_sp = pNewTask->thdb->cur_stack;
 620 }
 621
 622
 623 /***********************************************************************
 624  *           TASK_YieldToSystem
 625  *
 626  * Scheduler interface, this way we ensure that all "unsafe" events are
 627  * processed outside the scheduler.
 628  */
 629 void TASK_YieldToSystem(TDB* pTask)
 630 {
 631   MESSAGEQUEUE*         pQ;
 632
 633   Callbacks->CallTaskRescheduleProc();
 634
 635   if( pTask )
 636   {
 637     pQ = (MESSAGEQUEUE*)GlobalLock16(pTask->hQueue);
 638     if( pQ && pQ->flags & QUEUE_FLAG_XEVENT &&
 639             !(pQ->wakeBits & (QS_SENDMESSAGE | QS_SMRESULT)) )
 640     {
 641       pQ->flags &= ~QUEUE_FLAG_XEVENT;
 642       EVENT_WaitNetEvent( FALSE, FALSE );
 643     }
 644   }
 645 }
 646
 647
 648 /***********************************************************************
 649  *           InitTask  (KERNEL.91)
 650  *
 651  * Called by the application startup code.
 652  */
 653 void WINAPI InitTask( CONTEXT *context )
 654 {
 655     TDB *pTask;
 656     NE_MODULE *pModule;
 657     SEGTABLEENTRY *pSegTable;
 658     INSTANCEDATA *pinstance;
 659     LONG stacklow, stackhi;
 660
 661     if (context) EAX_reg(context) = 0;
 662     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
 663     if (!(pModule = MODULE_GetPtr( pTask->hModule ))) return;
 664
 665     /* This is a hack to install task USER signal handler before
 666      * implicitly loaded DLLs are initialized (see windows/user.c) */
 667
 668     pTask->userhandler = (USERSIGNALPROC)&USER_SignalProc;
 669
 670     /* Initialize implicitly loaded DLLs */
 671     NE_InitializeDLLs( pTask->hModule );
 672
 673     if (context)
 674     {
 675         /* Registers on return are:
 676          * ax     1 if OK, 0 on error
 677          * cx     stack limit in bytes
 678          * dx     cmdShow parameter
 679          * si     instance handle of the previous instance
 680          * di     instance handle of the new task
 681          * es:bx  pointer to command-line inside PSP
 682          */
 683         EAX_reg(context) = 1;
 684         EBX_reg(context) = pTask->pdb.cmdLine[0] ? 0x81 : 0x80;
 685
 686         if (!pTask->pdb.cmdLine[0]) EBX_reg(context) = 0x80;
 687         else
 688         {
 689             LPBYTE p = &pTask->pdb.cmdLine[1];
 690             while ((*p == ' ') || (*p == '\t')) p++;
 691             EBX_reg(context) = 0x80 + (p - pTask->pdb.cmdLine);
 692         }
 693         ECX_reg(context) = pModule->stack_size;
 694         EDX_reg(context) = pTask->nCmdShow;
 695         ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 696         EDI_reg(context) = (DWORD)pTask->hInstance;
 697         ES_reg (context) = (WORD)pTask->hPDB;
 698     }
 699
 700     /* Initialize the local heap */
 701     if ( pModule->heap_size )
 702     {
 703         LocalInit( pTask->hInstance, 0, pModule->heap_size );
 704     }
 705
 706     /* Initialize the INSTANCEDATA structure */
 707     pSegTable = NE_SEG_TABLE( pModule );
 708     stacklow = pSegTable[pModule->ss - 1].minsize;
 709     stackhi  = stacklow + pModule->stack_size;
 710     if (stackhi > 0xffff) stackhi = 0xffff;
 711     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 712     pinstance->stackbottom = stackhi; /* yup, that's right. Confused me too. */
 713     pinstance->stacktop    = stacklow;
 714     pinstance->stackmin    = OFFSETOF( pTask->thdb->cur_stack );
 715 }
 716
 717
 718 /***********************************************************************
 719  *           WaitEvent  (KERNEL.30)
 720  */
 721 BOOL16 WINAPI WaitEvent( HTASK16 hTask )
 722 {
 723     TDB *pTask;
 724
 725     if (!hTask) hTask = hCurrentTask;
 726     pTask = (TDB *)GlobalLock16( hTask );
 727     if (pTask->nEvents > 0)
 728     {
 729         pTask->nEvents--;
 730         return FALSE;
 731     }
 732     TASK_YieldToSystem(pTask);
 733
 734     /* When we get back here, we have an event */
 735
 736     if (pTask->nEvents > 0) pTask->nEvents--;
 737     return TRUE;
 738 }
 739
 740
 741 /***********************************************************************
 742  *           PostEvent  (KERNEL.31)
 743  */
 744 void WINAPI PostEvent( HTASK16 hTask )
 745 {
 746     TDB *pTask;
 747
 748     if (!hTask) hTask = hCurrentTask;
 749     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 750     pTask->nEvents++;
 751 }
 752
 753
 754 /***********************************************************************
 755  *           SetPriority  (KERNEL.32)
 756  */
 757 void WINAPI SetPriority( HTASK16 hTask, INT16 delta )
 758 {
 759     TDB *pTask;
 760     INT16 newpriority;
 761
 762     if (!hTask) hTask = hCurrentTask;
 763     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 764     newpriority = pTask->priority + delta;
 765     if (newpriority < -32) newpriority = -32;
 766     else if (newpriority > 15) newpriority = 15;
 767
 768     pTask->priority = newpriority + 1;
 769     TASK_UnlinkTask( hTask );
 770     TASK_LinkTask( hTask );
 771     pTask->priority--;
 772 }
 773
 774
 775 /***********************************************************************
 776  *           LockCurrentTask  (KERNEL.33)
 777  */
 778 HTASK16 WINAPI LockCurrentTask( BOOL16 bLock )
 779 {
 780     if (bLock) hLockedTask = hCurrentTask;
 781     else hLockedTask = 0;
 782     return hLockedTask;
 783 }
 784
 785
 786 /***********************************************************************
 787  *           IsTaskLocked  (KERNEL.122)
 788  */
 789 HTASK16 WINAPI IsTaskLocked(void)
 790 {
 791     return hLockedTask;
 792 }
 793
 794
 795 /***********************************************************************
 796  *           OldYield  (KERNEL.117)
 797  */
 798 void WINAPI OldYield(void)
 799 {
 800     TDB *pCurTask;
 801
 802     pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 803     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 804     TASK_YieldToSystem(pCurTask);
 805     if (pCurTask) pCurTask->nEvents--;
 806 }
 807
 808
 809 /***********************************************************************
 810  *           DirectedYield  (KERNEL.150)
 811  */
 812 void WINAPI DirectedYield( HTASK16 hTask )
 813 {
 814     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 815     pCurTask->hYieldTo = hTask;
 816     OldYield();
 817 }
 818
 819
 820 /***********************************************************************
 821  *           UserYield  (USER.332)
 822  */
 823 void WINAPI UserYield(void)
 824 {
 825     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 826     MESSAGEQUEUE *queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 827     /* Handle sent messages */
 828     while (queue && (queue->wakeBits & QS_SENDMESSAGE))
 829         QUEUE_ReceiveMessage( queue );
 830
 831     OldYield();
 832
 833     queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 834     while (queue && (queue->wakeBits & QS_SENDMESSAGE))
 835         QUEUE_ReceiveMessage( queue );
 836 }
 837
 838
 839 /***********************************************************************
 840  *           Yield16  (KERNEL.29)
 841  */
 842 void WINAPI Yield16(void)
 843 {
 844     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 845     if (pCurTask) pCurTask->hYieldTo = 0;
 846     if (pCurTask && pCurTask->hQueue) UserYield();
 847     else OldYield();
 848 }
 849
 850
 851 /***********************************************************************
 852  *           MakeProcInstance16  (KERNEL.51)
 853  */
 854 FARPROC16 WINAPI MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 855 {
 856     BYTE *thunk,*lfunc;
 857     SEGPTR thunkaddr;
 858
 859     if (!hInstance) return 0;
 860     if (__winelib) return func; /* func can be called directly in Winelib */
 861     thunkaddr = TASK_AllocThunk( hCurrentTask );
 862     if (!thunkaddr) return (FARPROC16)0;
 863     thunk = PTR_SEG_TO_LIN( thunkaddr );
 864     lfunc = PTR_SEG_TO_LIN( func );
 865
 866     TRACE(task, "(%08lx,%04x): got thunk %08lx\n",
 867                   (DWORD)func, hInstance, (DWORD)thunkaddr );
 868     if (((lfunc[0]==0x8c) && (lfunc[1]==0xd8)) ||
 869         ((lfunc[0]==0x1e) && (lfunc[1]==0x58))
 870     ) {
 871         fprintf(stderr,"FIXME: MakeProcInstance16 thunk would be useless for %p, overwriting with nop;nop;\n", func );
 872         lfunc[0]=0x90; /* nop */
 873         lfunc[1]=0x90; /* nop */
 874     }
 875
 876     *thunk++ = 0xb8;    /* movw instance, %ax */
 877     *thunk++ = (BYTE)(hInstance & 0xff);
 878     *thunk++ = (BYTE)(hInstance >> 8);
 879     *thunk++ = 0xea;    /* ljmp func */
 880     *(DWORD *)thunk = (DWORD)func;
 881     return (FARPROC16)thunkaddr;
 882 }
 883
 884
 885 /***********************************************************************
 886  *           FreeProcInstance16  (KERNEL.52)
 887  */
 888 void WINAPI FreeProcInstance16( FARPROC16 func )
 889 {
 890     TRACE(task, "(%08lx)\n", (DWORD)func );
 891     if (!__winelib) TASK_FreeThunk( hCurrentTask, (SEGPTR)func );
 892 }
 893
 894
 895 /**********************************************************************
 896  *          GetCodeHandle    (KERNEL.93)
 897  */
 898 HANDLE16 WINAPI GetCodeHandle( FARPROC16 proc )
 899 {
 900     HANDLE16 handle;
 901     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
 902
 903     if (__winelib) return 0;
 904
 905     /* Return the code segment containing 'proc'. */
 906     /* Not sure if this is really correct (shouldn't matter that much). */
 907
 908     /* Check if it is really a thunk */
 909     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
 910         handle = GlobalHandle16( thunk[6] + (thunk[7] << 8) );
 911     else
 912         handle = GlobalHandle16( HIWORD(proc) );
 913
 914     return handle;
 915 }
 916
 917
 918 /**********************************************************************
 919  *          DefineHandleTable16    (KERNEL.94)
 920  */
 921 BOOL16 WINAPI DefineHandleTable16( WORD wOffset )
 922 {
 923     return TRUE;  /* FIXME */
 924 }
 925
 926
 927 /***********************************************************************
 928  *           SetTaskQueue  (KERNEL.34)
 929  */
 930 HQUEUE16 WINAPI SetTaskQueue( HTASK16 hTask, HQUEUE16 hQueue )
 931 {
 932     HQUEUE16 hPrev;
 933     TDB *pTask;
 934
 935     if (!hTask) hTask = hCurrentTask;
 936     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 937
 938     hPrev = pTask->hQueue;
 939     pTask->hQueue = hQueue;
 940
 941     TIMER_SwitchQueue( hPrev, hQueue );
 942
 943     return hPrev;
 944 }
 945
 946
 947 /***********************************************************************
 948  *           GetTaskQueue  (KERNEL.35)
 949  */
 950 HQUEUE16 WINAPI GetTaskQueue( HTASK16 hTask )
 951 {
 952     TDB *pTask;
 953
 954     if (!hTask) hTask = hCurrentTask;
 955     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 956     return pTask->hQueue;
 957 }
 958
 959
 960 /***********************************************************************
 961  *           SwitchStackTo   (KERNEL.108)
 962  */
 963 void WINAPI SwitchStackTo( WORD seg, WORD ptr, WORD top )
 964 {
 965     TDB *pTask;
 966     STACK16FRAME *oldFrame, *newFrame;
 967     INSTANCEDATA *pData;
 968     UINT16 copySize;
 969
 970     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
 971     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
 972     TRACE(task, "old=%04x:%04x new=%04x:%04x\n",
 973                   SELECTOROF( pTask->thdb->cur_stack ),
 974                   OFFSETOF( pTask->thdb->cur_stack ), seg, ptr );
 975
 976     /* Save the old stack */
 977
 978     pData->old_ss_sp   = pTask->thdb->cur_stack;
 979     pData->stacktop    = top;
 980     pData->stackmin    = ptr;
 981     pData->stackbottom = ptr;
 982
 983     /* Switch to the new stack */
 984
 985     /* Note: we need to take the 3 arguments into account; otherwise,
 986      * the stack will underflow upon return from this function.
 987      */
 988     oldFrame = (STACK16FRAME *)PTR_SEG_TO_LIN( pTask->thdb->cur_stack );
 989     pTask->thdb->cur_stack = PTR_SEG_OFF_TO_SEGPTR( seg,
 990                              ptr - sizeof(STACK16FRAME) - 3 * sizeof(WORD) );
 991     newFrame = (STACK16FRAME *)PTR_SEG_TO_LIN( pTask->thdb->cur_stack );
 992
 993     /* Copy the stack frame and the local variables to the new stack */
 994
 995     copySize = oldFrame->bp - OFFSETOF(pData->old_ss_sp);
 996     memmove( newFrame, oldFrame, MAX( copySize, sizeof(STACK16FRAME) ));
 997 }
 998
 999
1000 /***********************************************************************
1001  *           SwitchStackBack   (KERNEL.109)
1002  *
1003  * Note: the function is declared as 'register' in the spec file in order
1004  * to make sure all registers are preserved, but we don't use them in any
1005  * way, so we don't need a CONTEXT* argument.
1006  */
1007 void WINAPI SwitchStackBack(void)
1008 {
1009     TDB *pTask;
1010     STACK16FRAME *oldFrame, *newFrame;
1011     INSTANCEDATA *pData;
1012
1013     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
1014     if (!(pData = (INSTANCEDATA *)GlobalLock16(SELECTOROF(pTask->thdb->cur_stack))))
1015         return;
1016     if (!pData->old_ss_sp)
1017     {
1018         fprintf( stderr, "SwitchStackBack: no previous SwitchStackTo\n" );
1019         return;
1020     }
1021     TRACE(task, "restoring stack %04x:%04x\n",
1022                  SELECTOROF(pData->old_ss_sp), OFFSETOF(pData->old_ss_sp) );
1023
1024     oldFrame = (STACK16FRAME *)PTR_SEG_TO_LIN( pTask->thdb->cur_stack );
1025
1026     /* Switch back to the old stack */
1027
1028     pTask->thdb->cur_stack = pData->old_ss_sp;
1029     pData->old_ss_sp = 0;
1030
1031     /* Build a stack frame for the return */
1032
1033     newFrame = (STACK16FRAME *)PTR_SEG_TO_LIN( pTask->thdb->cur_stack );
1034     newFrame->frame32 = oldFrame->frame32;
1035     if (TRACE_ON(relay))
1036     {
1037         newFrame->entry_ip = oldFrame->entry_ip;
1038         newFrame->entry_cs = oldFrame->entry_cs;
1039     }
1040 }
1041
1042
1043 /***********************************************************************
1044  *           GetTaskQueueDS  (KERNEL.118)
1045  */
1046 void WINAPI GetTaskQueueDS( CONTEXT *context )
1047 {
1048     DS_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1049 }
1050
1051
1052 /***********************************************************************
1053  *           GetTaskQueueES  (KERNEL.119)
1054  */
1055 void WINAPI GetTaskQueueES( CONTEXT *context )
1056 {
1057     ES_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1058 }
1059
1060
1061 /***********************************************************************
1062  *           GetCurrentTask   (KERNEL.36)
1063  */
1064 HTASK16 WINAPI GetCurrentTask(void)
1065 {
1066     return hCurrentTask;
1067 }
1068
1069 DWORD WINAPI WIN16_GetCurrentTask(void)
1070 {
1071     /* This is the version used by relay code; the first task is */
1072     /* returned in the high word of the result */
1073     return MAKELONG( hCurrentTask, hFirstTask );
1074 }
1075
1076
1077 /***********************************************************************
1078  *           GetCurrentPDB   (KERNEL.37)
1079  */
1080 HANDLE16 WINAPI GetCurrentPDB(void)
1081 {
1082     TDB *pTask;
1083
1084     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1085     return pTask->hPDB;
1086 }
1087
1088
1089 /***********************************************************************
1090  *           GetInstanceData   (KERNEL.54)
1091  */
1092 INT16 WINAPI GetInstanceData( HINSTANCE16 instance, WORD buffer, INT16 len )
1093 {
1094     char *ptr = (char *)GlobalLock16( instance );
1095     if (!ptr || !len) return 0;
1096     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1097     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1098     return len;
1099 }
1100
1101
1102 /***********************************************************************
1103  *           GetExeVersion   (KERNEL.105)
1104  */
1105 WORD WINAPI GetExeVersion(void)
1106 {
1107     TDB *pTask;
1108
1109     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1110     return pTask->version;
1111 }
1112
1113
1114 /***********************************************************************
1115  *           SetErrorMode16   (KERNEL.107)
1116  */
1117 UINT16 WINAPI SetErrorMode16( UINT16 mode )
1118 {
1119     TDB *pTask;
1120     UINT16 oldMode;
1121
1122     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1123     oldMode = pTask->error_mode;
1124     pTask->error_mode = mode;
1125     pTask->thdb->process->error_mode = mode;
1126     return oldMode;
1127 }
1128
1129
1130 /***********************************************************************
1131  *           SetErrorMode32   (KERNEL32.486)
1132  */
1133 UINT32 WINAPI SetErrorMode32( UINT32 mode )
1134 {
1135     return SetErrorMode16( (UINT16)mode );
1136 }
1137
1138
1139 /***********************************************************************
1140  *           GetDOSEnvironment   (KERNEL.131)
1141  */
1142 SEGPTR WINAPI GetDOSEnvironment(void)
1143 {
1144     TDB *pTask;
1145
1146     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1147     return PTR_SEG_OFF_TO_SEGPTR( pTask->pdb.environment, 0 );
1148 }
1149
1150
1151 /***********************************************************************
1152  *           GetNumTasks   (KERNEL.152)
1153  */
1154 UINT16 WINAPI GetNumTasks(void)
1155 {
1156     return nTaskCount;
1157 }
1158
1159
1160 /***********************************************************************
1161  *           GetTaskDS   (KERNEL.155)
1162  *
1163  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1164  * I don't think we need to bother with this.
1165  */
1166 HINSTANCE16 WINAPI GetTaskDS(void)
1167 {
1168     TDB *pTask;
1169
1170     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1171     return pTask->hInstance;
1172 }
1173
1174
1175 /***********************************************************************
1176  *           IsTask   (KERNEL.320)
1177  */
1178 BOOL16 WINAPI IsTask( HTASK16 hTask )
1179 {
1180     TDB *pTask;
1181
1182     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1183     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1184     return (pTask->magic == TDB_MAGIC);
1185 }
1186
1187
1188 /***********************************************************************
1189  *           SetTaskSignalProc   (KERNEL.38)
1190  *
1191  * Real 16-bit interface is provided by the THUNK_SetTaskSignalProc.
1192  */
1193 FARPROC16 WINAPI SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1194 {
1195     TDB *pTask;
1196     FARPROC16 oldProc;
1197
1198     if (!hTask) hTask = hCurrentTask;
1199     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return NULL;
1200     oldProc = (FARPROC16)pTask->userhandler;
1201     pTask->userhandler = (USERSIGNALPROC)proc;
1202     return oldProc;
1203 }
1204
1205
1206 /***********************************************************************
1207  *           SetSigHandler   (KERNEL.140)
1208  */
1209 WORD WINAPI SetSigHandler( FARPROC16 newhandler, FARPROC16* oldhandler,
1210                            UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1211 {
1212     FIXME(task,"(%p,%p,%p,%d,%d), unimplemented.\n",
1213           newhandler,oldhandler,oldmode,newmode,flag );
1214
1215     if (flag != 1) return 0;
1216     if (!newmode) newhandler = NULL;  /* Default handler */
1217     if (newmode != 4)
1218     {
1219         TDB *pTask;
1220
1221         if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1222         if (oldmode) *oldmode = pTask->signal_flags;
1223         pTask->signal_flags = newmode;
1224         if (oldhandler) *oldhandler = pTask->sighandler;
1225         pTask->sighandler = newhandler;
1226     }
1227     return 0;
1228 }
1229
1230
1231 /***********************************************************************
1232  *           GlobalNotify   (KERNEL.154)
1233  */
1234 VOID WINAPI GlobalNotify( FARPROC16 proc )
1235 {
1236     TDB *pTask;
1237
1238     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
1239     pTask->discardhandler = proc;
1240 }
1241
1242
1243 /***********************************************************************
1244  *           GetExePtr   (KERNEL.133)
1245  */
1246 HMODULE16 WINAPI GetExePtr( HANDLE16 handle )
1247 {
1248     char *ptr;
1249     HTASK16 hTask;
1250     HANDLE16 owner;
1251
1252       /* Check for module handle */
1253
1254     if (!(ptr = GlobalLock16( handle ))) return 0;
1255     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return handle;
1256
1257       /* Check the owner for module handle */
1258
1259     owner = FarGetOwner( handle );
1260     if (!(ptr = GlobalLock16( owner ))) return 0;
1261     if (((NE_MODULE *)ptr)->magic == IMAGE_OS2_SIGNATURE) return owner;
1262
1263       /* Search for this handle and its owner inside all tasks */
1264
1265     hTask = hFirstTask;
1266     while (hTask)
1267     {
1268         TDB *pTask = (TDB *)GlobalLock16( hTask );
1269         if ((hTask == handle) ||
1270             (pTask->hInstance == handle) ||
1271             (pTask->hQueue == handle) ||
1272             (pTask->hPDB == handle)) return pTask->hModule;
1273         if ((hTask == owner) ||
1274             (pTask->hInstance == owner) ||
1275             (pTask->hQueue == owner) ||
1276             (pTask->hPDB == owner)) return pTask->hModule;
1277         hTask = pTask->hNext;
1278     }
1279     return 0;
1280 }
1281
1282 /***********************************************************************
1283  *           TaskFirst   (TOOLHELP.63)
1284  */
1285 BOOL16 WINAPI TaskFirst( TASKENTRY *lpte )
1286 {
1287     lpte->hNext = hFirstTask;
1288     return TaskNext( lpte );
1289 }
1290
1291
1292 /***********************************************************************
1293  *           TaskNext   (TOOLHELP.64)
1294  */
1295 BOOL16 WINAPI TaskNext( TASKENTRY *lpte )
1296 {
1297     TDB *pTask;
1298     INSTANCEDATA *pInstData;
1299
1300     TRACE(toolhelp, "(%p): task=%04x\n", lpte, lpte->hNext );
1301     if (!lpte->hNext) return FALSE;
1302     pTask = (TDB *)GlobalLock16( lpte->hNext );
1303     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1304     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1305     lpte->hTask         = lpte->hNext;
1306     lpte->hTaskParent   = pTask->hParent;
1307     lpte->hInst         = pTask->hInstance;
1308     lpte->hModule       = pTask->hModule;
1309     lpte->wSS           = SELECTOROF( pTask->thdb->cur_stack );
1310     lpte->wSP           = OFFSETOF( pTask->thdb->cur_stack );
1311     lpte->wStackTop     = pInstData->stacktop;
1312     lpte->wStackMinimum = pInstData->stackmin;
1313     lpte->wStackBottom  = pInstData->stackbottom;
1314     lpte->wcEvents      = pTask->nEvents;
1315     lpte->hQueue        = pTask->hQueue;
1316     strncpy( lpte->szModule, pTask->module_name, 8 );
1317     lpte->szModule[8]   = '\0';
1318     lpte->wPSPOffset    = 0x100;  /*??*/
1319     lpte->hNext         = pTask->hNext;
1320     return TRUE;
1321 }
1322
1323
1324 /***********************************************************************
1325  *           TaskFindHandle   (TOOLHELP.65)
1326  */
1327 BOOL16 WINAPI TaskFindHandle( TASKENTRY *lpte, HTASK16 hTask )
1328 {
1329     lpte->hNext = hTask;
1330     return TaskNext( lpte );
1331 }
1332
1333
1334 /***********************************************************************
1335  *           GetAppCompatFlags16   (KERNEL.354)
1336  */
1337 DWORD WINAPI GetAppCompatFlags16( HTASK16 hTask )
1338 {
1339     return GetAppCompatFlags32( hTask );
1340 }
1341
1342
1343 /***********************************************************************
1344  *           GetAppCompatFlags32   (USER32.206)
1345  */
1346 DWORD WINAPI GetAppCompatFlags32( HTASK32 hTask )
1347 {
1348     TDB *pTask;
1349
1350     if (!hTask) hTask = GetCurrentTask();
1351     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1352     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1353     return pTask->compat_flags;
1354 }