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 "task.h"
  13 #include "callback.h"
  14 #include "directory.h"
  15 #include "dos_fs.h"
  16 #include "file.h"
  17 #include "debugger.h"
  18 #include "global.h"
  19 #include "instance.h"
  20 #include "message.h"
  21 #include "miscemu.h"
  22 #include "module.h"
  23 #include "neexe.h"
  24 #include "options.h"
  25 #include "peexe.h"
  26 #include "pe_image.h"
  27 #include "queue.h"
  28 #include "stackframe.h"
  29 #include "toolhelp.h"
  30 #include "stddebug.h"
  31 #include "debug.h"
  32 #include "dde_proc.h"
  33
  34   /* Min. number of thunks allocated when creating a new segment */
  35 #define MIN_THUNKS  32
  36
  37   /* 32-bit stack size for each task */
  38 #define STACK32_SIZE 0x10000
  39
  40 extern void USER_AppExit( HTASK16, HINSTANCE16, HQUEUE16 );
  41
  42   /* Saved 16-bit stack for current process (Win16 only) */
  43 WORD IF1632_Saved16_ss = 0;
  44 WORD IF1632_Saved16_sp = 0;
  45
  46   /* Saved 32-bit stack for current process (Win16 only) */
  47 DWORD IF1632_Saved32_esp = 0;
  48 SEGPTR IF1632_Stack32_base = 0;
  49
  50   /* Original Unix stack */
  51 DWORD IF1632_Original32_esp;
  52
  53 static HTASK16 hFirstTask = 0;
  54 static HTASK16 hCurrentTask = 0;
  55 static HTASK16 hTaskToKill = 0;
  56 static HTASK16 hLockedTask = 0;
  57 static WORD nTaskCount = 0;
  58 static HANDLE hDOSEnvironment = 0;
  59
  60   /* TASK_Reschedule() 16-bit entry point */
  61 static FARPROC16 TASK_RescheduleProc;
  62
  63 #ifdef WINELIB
  64 #define TASK_SCHEDULE()  TASK_Reschedule()
  65 #else
  66 #define TASK_SCHEDULE()  CallTo16_word_(TASK_RescheduleProc)
  67 #endif
  68
  69 static HANDLE TASK_CreateDOSEnvironment(void);
  70
  71 /***********************************************************************
  72  *           TASK_Init
  73  */
  74 BOOL32 TASK_Init(void)
  75 {
  76     TASK_RescheduleProc = MODULE_GetWndProcEntry16( "TASK_Reschedule" );
  77     if (!(hDOSEnvironment = TASK_CreateDOSEnvironment()))
  78         fprintf( stderr, "Not enough memory for DOS Environment\n" );
  79     return (hDOSEnvironment != 0);
  80 }
  81
  82
  83 /***********************************************************************
  84  *           TASK_GetNextTask
  85  */
  86 HTASK TASK_GetNextTask( HTASK hTask )
  87 {
  88     TDB* pTask = (TDB*)GlobalLock16(hTask);
  89
  90     if (pTask->hNext) return pTask->hNext;
  91     return (hFirstTask != hTask) ? hFirstTask : 0;
  92 }
  93
  94
  95 /***********************************************************************
  96  *           TASK_CreateDOSEnvironment
  97  *
  98  * Create the original DOS environment.
  99  */
 100 static HANDLE TASK_CreateDOSEnvironment(void)
 101 {
 102     static const char program_name[] = "KRNL386.EXE";
 103     char **e, *p;
 104     int initial_size, size, i, winpathlen, sysdirlen;
 105     HANDLE handle;
 106
 107     extern char **environ;
 108
 109     /* DOS environment format:
 110      * ASCIIZ   string 1
 111      * ASCIIZ   string 2
 112      * ...
 113      * ASCIIZ   string n
 114      * ASCIIZ   PATH=xxx
 115      * BYTE     0
 116      * WORD     1
 117      * ASCIIZ   program name (e.g. C:\WINDOWS\SYSTEM\KRNL386.EXE)
 118      */
 119
 120     /* First compute the size of the fixed part of the environment */
 121
 122     for (i = winpathlen = 0; ; i++)
 123     {
 124         int len = DIR_GetDosPath( i, NULL, 0 );
 125         if (!len) break;
 126         winpathlen += len + 1;
 127     }
 128     if (!winpathlen) winpathlen = 1;
 129     sysdirlen  = GetSystemDirectory32A( NULL, 0 ) + 1;
 130     initial_size = 5 + winpathlen +           /* PATH=xxxx */
 131                    1 +                        /* BYTE 0 at end */
 132                    sizeof(WORD) +             /* WORD 1 */
 133                    sysdirlen +                /* program directory */
 134                    strlen(program_name) + 1;  /* program name */
 135
 136     /* Compute the total size of the Unix environment (except path) */
 137
 138     for (e = environ, size = initial_size; *e; e++)
 139     {
 140         if (lstrncmpi32A(*e, "path=", 5))
 141         {
 142             int len = strlen(*e) + 1;
 143             if (size + len >= 32767)
 144             {
 145                 fprintf( stderr, "Warning: environment larger than 32k.\n" );
 146                 break;
 147             }
 148             size += len;
 149         }
 150     }
 151
 152
 153     /* Now allocate the environment */
 154
 155     if (!(handle = GlobalAlloc16( GMEM_FIXED, size ))) return 0;
 156     p = (char *)GlobalLock16( handle );
 157
 158     /* And fill it with the Unix environment */
 159
 160     for (e = environ, size = initial_size; *e; e++)
 161     {
 162         if (lstrncmpi32A(*e, "path=", 5))
 163         {
 164             int len = strlen(*e) + 1;
 165             if (size + len >= 32767) break;
 166             strcpy( p, *e );
 167             size += len;
 168             p    += len;
 169         }
 170     }
 171
 172     /* Now add the path */
 173
 174     strcpy( p, "PATH=" );
 175     for (i = 0, p += 5; ; i++)
 176     {
 177         if (!DIR_GetDosPath( i, p, winpathlen )) break;
 178         p += strlen(p);
 179         *p++ = ';';
 180     }
 181     if (p[-1] == ';') p[-1] = '\0';
 182     else p++;
 183
 184     /* Now add the program name */
 185
 186     *p++ = '\0';
 187     PUT_WORD( p, 1 );
 188     p += sizeof(WORD);
 189     GetSystemDirectory32A( p, sysdirlen );
 190     strcat( p, "\\" );
 191     strcat( p, program_name );
 192
 193     /* Display it */
 194
 195     p = (char *) GlobalLock16( handle );
 196     dprintf_task(stddeb, "Master DOS environment at %p\n", p);
 197     for (; *p; p += strlen(p) + 1) dprintf_task(stddeb, "    %s\n", p);
 198     dprintf_task( stddeb, "Progname: %s\n", p+3 );
 199
 200     return handle;
 201 }
 202
 203
 204 /***********************************************************************
 205  *           TASK_LinkTask
 206  */
 207 static void TASK_LinkTask( HTASK16 hTask )
 208 {
 209     HTASK16 *prevTask;
 210     TDB *pTask;
 211
 212     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 213     prevTask = &hFirstTask;
 214     while (*prevTask)
 215     {
 216         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
 217         if (prevTaskPtr->priority >= pTask->priority) break;
 218         prevTask = &prevTaskPtr->hNext;
 219     }
 220     pTask->hNext = *prevTask;
 221     *prevTask = hTask;
 222     nTaskCount++;
 223 }
 224
 225
 226 /***********************************************************************
 227  *           TASK_UnlinkTask
 228  */
 229 static void TASK_UnlinkTask( HTASK16 hTask )
 230 {
 231     HTASK16 *prevTask;
 232     TDB *pTask;
 233
 234     prevTask = &hFirstTask;
 235     while (*prevTask && (*prevTask != hTask))
 236     {
 237         pTask = (TDB *)GlobalLock16( *prevTask );
 238         prevTask = &pTask->hNext;
 239     }
 240     if (*prevTask)
 241     {
 242         pTask = (TDB *)GlobalLock16( *prevTask );
 243         *prevTask = pTask->hNext;
 244         pTask->hNext = 0;
 245         nTaskCount--;
 246     }
 247 }
 248
 249
 250 /***********************************************************************
 251  *           TASK_CreateThunks
 252  *
 253  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 254  * and containing 'count' entries.
 255  */
 256 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 257 {
 258     int i;
 259     WORD free;
 260     THUNKS *pThunk;
 261
 262     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 263     pThunk->next = 0;
 264     pThunk->magic = THUNK_MAGIC;
 265     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 266     free = pThunk->free;
 267     for (i = 0; i < count-1; i++)
 268     {
 269         free += 8;  /* Offset of next thunk */
 270         pThunk->thunks[4*i] = free;
 271     }
 272     pThunk->thunks[4*i] = 0;  /* Last thunk */
 273 }
 274
 275
 276 /***********************************************************************
 277  *           TASK_AllocThunk
 278  *
 279  * Allocate a thunk for MakeProcInstance().
 280  */
 281 #ifndef WINELIB32
 282 static SEGPTR TASK_AllocThunk( HTASK hTask )
 283 {
 284     TDB *pTask;
 285     THUNKS *pThunk;
 286     WORD sel, base;
 287
 288     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 289     sel = pTask->hCSAlias;
 290     pThunk = &pTask->thunks;
 291     base = (int)pThunk - (int)pTask;
 292     while (!pThunk->free)
 293     {
 294         sel = pThunk->next;
 295         if (!sel)  /* Allocate a new segment */
 296         {
 297             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 298                                 pTask->hPDB, TRUE, FALSE, FALSE );
 299             if (!sel) return (SEGPTR)0;
 300             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 301             pThunk->next = sel;
 302         }
 303         pThunk = (THUNKS *)GlobalLock16( sel );
 304         base = 0;
 305     }
 306     base += pThunk->free;
 307     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 308     return PTR_SEG_OFF_TO_SEGPTR( sel, base );
 309 }
 310 #endif
 311
 312
 313 /***********************************************************************
 314  *           TASK_FreeThunk
 315  *
 316  * Free a MakeProcInstance() thunk.
 317  */
 318 #ifndef WINELIB32
 319 static BOOL TASK_FreeThunk( HTASK hTask, SEGPTR thunk )
 320 {
 321     TDB *pTask;
 322     THUNKS *pThunk;
 323     WORD sel, base;
 324
 325     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 326     sel = pTask->hCSAlias;
 327     pThunk = &pTask->thunks;
 328     base = (int)pThunk - (int)pTask;
 329     while (sel && (sel != HIWORD(thunk)))
 330     {
 331         sel = pThunk->next;
 332         pThunk = (THUNKS *)GlobalLock16( sel );
 333         base = 0;
 334     }
 335     if (!sel) return FALSE;
 336     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 337     pThunk->free = LOWORD(thunk) - base;
 338     return TRUE;
 339 }
 340 #endif
 341
 342
 343 /***********************************************************************
 344  *           TASK_CallToStart
 345  *
 346  * 32-bit entry point for a new task. This function is responsible for
 347  * setting up the registers and jumping to the 16-bit entry point.
 348  */
 349 #ifndef WINELIB
 350 static void TASK_CallToStart(void)
 351 {
 352     int cs_reg, ds_reg, ip_reg;
 353     TDB *pTask = (TDB *)GlobalLock16( hCurrentTask );
 354     NE_MODULE *pModule = MODULE_GetPtr( pTask->hModule );
 355     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 356
 357     /* Registers at initialization must be:
 358      * ax   zero
 359      * bx   stack size in bytes
 360      * cx   heap size in bytes
 361      * si   previous app instance
 362      * di   current app instance
 363      * bp   zero
 364      * es   selector to the PSP
 365      * ds   dgroup of the application
 366      * ss   stack selector
 367      * sp   top of the stack
 368      */
 369
 370     cs_reg = pSegTable[pModule->cs - 1].selector;
 371     ip_reg = pModule->ip;
 372     ds_reg = pSegTable[pModule->dgroup - 1].selector;
 373
 374     IF1632_Saved16_ss = pTask->ss;
 375     IF1632_Saved16_sp = pTask->sp;
 376     dprintf_task( stddeb, "Starting main program: cs:ip=%04x:%04x ds=%04x ss:sp=%04x:%04x\n",
 377                  cs_reg, ip_reg, ds_reg,
 378                  IF1632_Saved16_ss, IF1632_Saved16_sp);
 379
 380     CallTo16_regs_( (FARPROC16)(cs_reg << 16 | ip_reg), ds_reg,
 381                    pTask->hPDB /*es*/, 0 /*bp*/, 0 /*ax*/,
 382                    pModule->stack_size /*bx*/, pModule->heap_size /*cx*/,
 383                    0 /*dx*/, 0 /*si*/, ds_reg /*di*/ );
 384
 385     /* This should never return */
 386     fprintf( stderr, "TASK_CallToStart: Main program returned!\n" );
 387     TASK_KillCurrentTask( 1 );
 388 }
 389 #endif
 390
 391
 392 /***********************************************************************
 393  *           TASK_CreateTask
 394  */
 395 HTASK16 TASK_CreateTask( HMODULE16 hModule, HINSTANCE16 hInstance,
 396                          HINSTANCE16 hPrevInstance, HANDLE16 hEnvironment,
 397                          LPCSTR cmdLine, UINT16 cmdShow )
 398 {
 399     HTASK hTask;
 400     TDB *pTask;
 401     HANDLE hParentEnv;
 402     NE_MODULE *pModule;
 403     SEGTABLEENTRY *pSegTable;
 404     LPSTR name;
 405     char filename[256];
 406     char *stack16Top, *stack32Top;
 407     STACK16FRAME *frame16;
 408     STACK32FRAME *frame32;
 409 #ifndef WINELIB32
 410     extern DWORD CALLTO16_RetAddr_word;
 411 #endif
 412
 413     if (!(pModule = MODULE_GetPtr( hModule ))) return 0;
 414     pSegTable = NE_SEG_TABLE( pModule );
 415
 416       /* Allocate the task structure */
 417
 418     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 419                           hModule, FALSE, FALSE, FALSE );
 420     if (!hTask) return 0;
 421     pTask = (TDB *)GlobalLock16( hTask );
 422
 423       /* Allocate the new environment block */
 424
 425     if (!(hParentEnv = hEnvironment))
 426     {
 427         TDB *pParent = (TDB *)GlobalLock16( hCurrentTask );
 428         hParentEnv = pParent ? pParent->pdb.environment : hDOSEnvironment;
 429     }
 430     /* FIXME: do we really need to make a copy also when */
 431     /*        we don't use the parent environment? */
 432     if (!(hEnvironment = GlobalAlloc16( GMEM_FIXED, GlobalSize16(hParentEnv))))
 433     {
 434         GlobalFree16( hTask );
 435         return 0;
 436     }
 437     memcpy( GlobalLock16( hEnvironment ), GlobalLock16( hParentEnv ),
 438             GlobalSize16( hParentEnv ) );
 439
 440       /* Get current directory */
 441
 442     GetModuleFileName( hModule, filename, sizeof(filename) );
 443     name = strrchr(filename, '\\');
 444     if (name) *(name+1) = 0;
 445
 446       /* Fill the task structure */
 447
 448     pTask->nEvents       = 1;  /* So the task can be started */
 449     pTask->hSelf         = hTask;
 450     pTask->flags         = 0;
 451     pTask->version       = pModule->expected_version;
 452     pTask->hInstance     = hInstance;
 453     pTask->hPrevInstance = hPrevInstance;
 454     pTask->hModule       = hModule;
 455     pTask->hParent       = hCurrentTask;
 456     pTask->curdrive      = filename[0] - 'A' + 0x80;
 457     strcpy( pTask->curdir, filename+2 );
 458     pTask->magic         = TDB_MAGIC;
 459     pTask->nCmdShow      = cmdShow;
 460
 461       /* Create the thunks block */
 462
 463     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 464
 465       /* Copy the module name */
 466
 467     name = MODULE_GetModuleName( hModule );
 468     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 469
 470       /* Allocate a selector for the PDB */
 471
 472     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB),
 473                                       hModule, FALSE, FALSE, FALSE, NULL );
 474
 475       /* Fill the PDB */
 476
 477     pTask->pdb.int20 = 0x20cd;
 478     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 479 #ifndef WINELIB
 480     *(FARPROC16 *)&pTask->pdb.dispatcher[1] = MODULE_GetEntryPoint( GetModuleHandle("KERNEL"), 102 );  /* KERNEL.102 is DOS3Call() */
 481     pTask->pdb.savedint22 = INT_GetHandler( 0x22 );
 482     pTask->pdb.savedint23 = INT_GetHandler( 0x23 );
 483     pTask->pdb.savedint24 = INT_GetHandler( 0x24 );
 484 #endif
 485     pTask->pdb.fileHandlesPtr =
 486         PTR_SEG_OFF_TO_SEGPTR( GlobalHandleToSel(pTask->hPDB),
 487                                (int)&((PDB *)0)->fileHandles );
 488     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 489     pTask->pdb.environment    = hEnvironment;
 490     pTask->pdb.nbFiles        = 20;
 491     lstrcpyn32A( pTask->pdb.cmdLine + 1, cmdLine, 127 );
 492     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 493
 494       /* Get the compatibility flags */
 495
 496     pTask->compat_flags = GetProfileInt( "Compatibility", name, 0 );
 497
 498       /* Allocate a code segment alias for the TDB */
 499
 500     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 501                                           sizeof(TDB), pTask->hPDB, TRUE,
 502                                           FALSE, FALSE, NULL );
 503
 504       /* Set the owner of the environment block */
 505
 506     FarSetOwner( pTask->pdb.environment, pTask->hPDB );
 507
 508       /* Default DTA overwrites command-line */
 509
 510     pTask->dta = PTR_SEG_OFF_TO_SEGPTR( pTask->hPDB,
 511                                 (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 512
 513       /* Allocate the 32-bit stack */
 514
 515     pTask->hStack32 = GLOBAL_Alloc( GMEM_FIXED, STACK32_SIZE, pTask->hPDB,
 516                                     FALSE, FALSE, FALSE );
 517
 518       /* Create the 32-bit stack frame */
 519
 520     *(DWORD *)GlobalLock16(pTask->hStack32) = 0xDEADBEEF;
 521     stack32Top = (char*)GlobalLock16(pTask->hStack32) + STACK32_SIZE;
 522     frame32 = (STACK32FRAME *)stack32Top - 1;
 523     frame32->saved_esp = (DWORD)stack32Top;
 524     frame32->edi = 0;
 525     frame32->esi = 0;
 526     frame32->edx = 0;
 527     frame32->ecx = 0;
 528     frame32->ebx = 0;
 529     frame32->ebp = 0;
 530 #ifndef WINELIB
 531     frame32->retaddr = (DWORD)TASK_CallToStart;
 532     frame32->codeselector = WINE_CODE_SELECTOR;
 533 #endif
 534     pTask->esp = (DWORD)frame32;
 535
 536       /* Create the 16-bit stack frame */
 537
 538     pTask->ss = hInstance;
 539     pTask->sp = ((pModule->sp != 0) ? pModule->sp :
 540                  pSegTable[pModule->ss-1].minsize + pModule->stack_size) & ~1;
 541     stack16Top = (char *)PTR_SEG_OFF_TO_LIN( pTask->ss, pTask->sp );
 542     frame16 = (STACK16FRAME *)stack16Top - 1;
 543     frame16->saved_ss = 0;
 544     frame16->saved_sp = 0;
 545     frame16->ds = frame16->es = pTask->hInstance;
 546     frame16->entry_point = 0;
 547     frame16->entry_ip = OFFSETOF(TASK_RescheduleProc) + 14;
 548     frame16->entry_cs = SELECTOROF(TASK_RescheduleProc);
 549     frame16->bp = 0;
 550 #ifndef WINELIB
 551     frame16->ip = LOWORD( CALLTO16_RetAddr_word );
 552     frame16->cs = HIWORD( CALLTO16_RetAddr_word );
 553 #endif  /* WINELIB */
 554     pTask->sp -= sizeof(STACK16FRAME);
 555
 556       /* If there's no 16-bit stack yet, use a part of the new task stack */
 557       /* This is only needed to have a stack to switch from on the first  */
 558       /* call to DirectedYield(). */
 559
 560     if (!IF1632_Saved16_ss)
 561     {
 562         IF1632_Saved16_ss = pTask->ss;
 563         IF1632_Saved16_sp = pTask->sp;
 564     }
 565
 566       /* Add a breakpoint at the start of the task */
 567
 568 #ifndef WINELIB
 569     if (Options.debug)
 570     {
 571         if (pModule->flags & NE_FFLAGS_WIN32)
 572         {
 573             DBG_ADDR addr = { 0, pModule->pe_module->load_addr +
 574                               pModule->pe_module->pe_header->opt_coff.AddressOfEntryPoint };
 575             fprintf( stderr, "Win32 task '%s': ", name );
 576             DEBUG_AddBreakpoint( &addr );
 577         }
 578         else
 579         {
 580             DBG_ADDR addr = { pSegTable[pModule->cs-1].selector, pModule->ip };
 581             fprintf( stderr, "Win16 task '%s': ", name );
 582             DEBUG_AddBreakpoint( &addr );
 583         }
 584     }
 585 #endif  /* WINELIB */
 586
 587       /* Add the task to the linked list */
 588
 589     TASK_LinkTask( hTask );
 590
 591     dprintf_task( stddeb, "CreateTask: module='%s' cmdline='%s' task=%04x\n",
 592                   name, cmdLine, hTask );
 593
 594     return hTask;
 595 }
 596
 597
 598 /***********************************************************************
 599  *           TASK_DeleteTask
 600  */
 601 static void TASK_DeleteTask( HTASK hTask )
 602 {
 603     TDB *pTask;
 604     HANDLE hPDB;
 605
 606     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 607     hPDB = pTask->hPDB;
 608
 609     /* Free the task module */
 610
 611     FreeModule16( pTask->hModule );
 612
 613     /* Close all open files of this task */
 614
 615     FILE_CloseAllFiles( pTask->hPDB );
 616
 617     /* Free the selector aliases */
 618
 619     GLOBAL_FreeBlock( pTask->hCSAlias );
 620     GLOBAL_FreeBlock( pTask->hPDB );
 621
 622     /* Free the task structure itself */
 623
 624     GlobalFree16( hTask );
 625
 626     /* Free all memory used by this task (including the 32-bit stack, */
 627     /* the environment block and the thunk segments). */
 628
 629     GlobalFreeAll( hPDB );
 630 }
 631
 632
 633 /***********************************************************************
 634  *           TASK_KillCurrentTask
 635  *
 636  * Kill the currently running task. As it's not possible to kill the
 637  * current task like this, it is simply marked for destruction, and will
 638  * be killed when either TASK_Reschedule or this function is called again
 639  * in the context of another task.
 640  */
 641 void TASK_KillCurrentTask( INT16 exitCode )
 642 {
 643     extern void EXEC_ExitWindows( int retCode );
 644
 645     TDB* pTask = (TDB*) GlobalLock16( hCurrentTask );
 646     if (!pTask) EXEC_ExitWindows(0);  /* No current task yet */
 647
 648     /* Perform USER cleanup */
 649
 650     USER_AppExit( hCurrentTask, pTask->hInstance, pTask->hQueue );
 651
 652     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 653     {
 654         /* If another task is already marked for destruction, */
 655         /* we can kill it now, as we are in another context.  */
 656         TASK_DeleteTask( hTaskToKill );
 657     }
 658
 659     if (nTaskCount <= 1)
 660     {
 661         dprintf_task( stddeb, "Killing the last task, exiting\n" );
 662         EXEC_ExitWindows( 0 );
 663     }
 664
 665     /* Remove the task from the list to be sure we never switch back to it */
 666     TASK_UnlinkTask( hCurrentTask );
 667
 668     hTaskToKill = hCurrentTask;
 669     hLockedTask = 0;
 670
 671     Yield();
 672     /* We should never return from this Yield() */
 673
 674     fprintf(stderr,"Return of the living dead %04x!!!\n", hCurrentTask);
 675     exit(1);
 676 }
 677
 678 /***********************************************************************
 679  *           TASK_YieldToSystem
 680  *
 681  * Scheduler interface, this way we ensure that all "unsafe" events are
 682  * processed outside the scheduler.
 683  */
 684 void TASK_YieldToSystem(TDB* pTask)
 685 {
 686   MESSAGEQUEUE*         pQ;
 687
 688   TASK_SCHEDULE();
 689
 690   if( pTask )
 691   {
 692     pQ = (MESSAGEQUEUE*)GlobalLock16(pTask->hQueue);
 693     if( pQ && pQ->flags & QUEUE_FLAG_XEVENT )
 694     {
 695       pQ->flags &= ~QUEUE_FLAG_XEVENT;
 696       EVENT_WaitXEvent( FALSE, FALSE );
 697     }
 698   }
 699 }
 700
 701 /***********************************************************************
 702  *           TASK_Reschedule
 703  *
 704  * This is where all the magic of task-switching happens!
 705  *
 706  * Note: This function should only be called via the TASK_YieldToSystem()
 707  *       wrapper, to make sure that all the context is saved correctly.
 708  *
 709  *       It must not call functions that may yield control.
 710  */
 711 void TASK_Reschedule(void)
 712 {
 713     TDB *pOldTask = NULL, *pNewTask;
 714     HTASK hTask = 0;
 715
 716 #ifdef CONFIG_IPC
 717     dde_reschedule();
 718 #endif
 719       /* First check if there's a task to kill */
 720
 721     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 722     {
 723         TASK_DeleteTask( hTaskToKill );
 724         hTaskToKill = 0;
 725     }
 726
 727     /* Find a task to yield to */
 728
 729     pOldTask = (TDB *)GlobalLock16( hCurrentTask );
 730     if (pOldTask && pOldTask->hYieldTo)
 731     {
 732         /* check for DirectedYield() */
 733
 734         hTask = pOldTask->hYieldTo;
 735         if (!(pNewTask = (TDB *)GlobalLock16( hTask )) || !pNewTask->nEvents)
 736             hTask = 0;
 737     }
 738
 739     /* extract hardware events only! */
 740
 741     EVENT_WaitXEvent( FALSE, TRUE );
 742
 743     while (!hTask)
 744     {
 745         /* Find a task that has an event pending */
 746
 747         hTask = hFirstTask;
 748         while (hTask)
 749         {
 750             pNewTask = (TDB *)GlobalLock16( hTask );
 751
 752             dprintf_task( stddeb, "\ttask = %04x, events = %i\n", hTask, pNewTask->nEvents);
 753
 754             if (pNewTask->nEvents) break;
 755             hTask = pNewTask->hNext;
 756         }
 757         if (hLockedTask && (hTask != hLockedTask)) hTask = 0;
 758         if (hTask) break;
 759
 760         /* No task found, wait for some events to come in */
 761
 762         EVENT_WaitXEvent( TRUE, TRUE );
 763     }
 764
 765     if (hTask == hCurrentTask)
 766     {
 767        dprintf_task( stddeb, "returning to the current task(%04x)\n", hTask );
 768        return;  /* Nothing to do */
 769     }
 770     pNewTask = (TDB *)GlobalLock16( hTask );
 771     dprintf_task( stddeb, "Switching to task %04x (%.8s)\n",
 772                   hTask, pNewTask->module_name );
 773
 774       /* Save the stacks of the previous task (if any) */
 775
 776     if (pOldTask)
 777     {
 778         pOldTask->ss  = IF1632_Saved16_ss;
 779         pOldTask->sp  = IF1632_Saved16_sp;
 780         pOldTask->esp = IF1632_Saved32_esp;
 781     }
 782     else IF1632_Original32_esp = IF1632_Saved32_esp;
 783
 784      /* Make the task the last in the linked list (round-robin scheduling) */
 785
 786     pNewTask->priority++;
 787     TASK_UnlinkTask( hTask );
 788     TASK_LinkTask( hTask );
 789     pNewTask->priority--;
 790
 791       /* Switch to the new stack */
 792
 793     hCurrentTask = hTask;
 794     IF1632_Saved16_ss   = pNewTask->ss;
 795     IF1632_Saved16_sp   = pNewTask->sp;
 796     IF1632_Saved32_esp  = pNewTask->esp;
 797     IF1632_Stack32_base = WIN16_GlobalLock16( pNewTask->hStack32 );
 798 }
 799
 800
 801 /***********************************************************************
 802  *           InitTask  (KERNEL.91)
 803  */
 804 #ifdef WINELIB
 805 void InitTask(void)
 806 #else
 807 void InitTask( SIGCONTEXT *context )
 808 #endif
 809 {
 810     TDB *pTask;
 811     NE_MODULE *pModule;
 812     SEGTABLEENTRY *pSegTable;
 813     INSTANCEDATA *pinstance;
 814     LONG stacklow, stackhi;
 815
 816 #ifndef WINELIB
 817     EAX_reg(context) = 0;
 818 #endif
 819     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
 820     if (!(pModule = MODULE_GetPtr( pTask->hModule ))) return;
 821
 822 #ifndef WINELIB
 823     NE_InitializeDLLs( pTask->hModule );
 824
 825     /* Registers on return are:
 826      * ax     1 if OK, 0 on error
 827      * cx     stack limit in bytes
 828      * dx     cmdShow parameter
 829      * si     instance handle of the previous instance
 830      * di     instance handle of the new task
 831      * es:bx  pointer to command-line inside PSP
 832      */
 833     EAX_reg(context) = 1;
 834     EBX_reg(context) = 0x81;
 835     ECX_reg(context) = pModule->stack_size;
 836     EDX_reg(context) = pTask->nCmdShow;
 837     ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 838     EDI_reg(context) = (DWORD)pTask->hInstance;
 839     ES_reg (context) = (WORD)pTask->hPDB;
 840
 841     /* Initialize the local heap */
 842     if ( pModule->heap_size )
 843     {
 844         LocalInit( pTask->hInstance, 0, pModule->heap_size );
 845     }
 846 #endif
 847
 848     /* Initialize the INSTANCEDATA structure */
 849     pSegTable = NE_SEG_TABLE( pModule );
 850     stacklow = pSegTable[pModule->ss - 1].minsize;
 851     stackhi  = stacklow + pModule->stack_size;
 852     if (stackhi > 0xffff) stackhi = 0xffff;
 853     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 854     pinstance->stackbottom = stackhi; /* yup, that's right. Confused me too. */
 855     pinstance->stacktop    = stacklow;
 856 #ifndef WINELIB
 857     pinstance->stackmin    = IF1632_Saved16_sp;
 858 #endif
 859 }
 860
 861
 862 /***********************************************************************
 863  *           WaitEvent  (KERNEL.30)
 864  */
 865 BOOL WaitEvent( HTASK hTask )
 866 {
 867     TDB *pTask;
 868
 869     if (!hTask) hTask = hCurrentTask;
 870     pTask = (TDB *)GlobalLock16( hTask );
 871     if (pTask->nEvents > 0)
 872     {
 873         pTask->nEvents--;
 874         return FALSE;
 875     }
 876     TASK_YieldToSystem(pTask);
 877
 878     /* When we get back here, we have an event */
 879
 880     if (pTask->nEvents > 0) pTask->nEvents--;
 881     return TRUE;
 882 }
 883
 884
 885 /***********************************************************************
 886  *           PostEvent  (KERNEL.31)
 887  */
 888 void PostEvent( HTASK hTask )
 889 {
 890     TDB *pTask;
 891
 892     if (!hTask) hTask = hCurrentTask;
 893     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 894     pTask->nEvents++;
 895 }
 896
 897
 898 /***********************************************************************
 899  *           SetPriority  (KERNEL.32)
 900  */
 901 void SetPriority( HTASK hTask, int delta )
 902 {
 903     TDB *pTask;
 904     int newpriority;
 905
 906     if (!hTask) hTask = hCurrentTask;
 907     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 908     newpriority = pTask->priority + delta;
 909     if (newpriority < -32) newpriority = -32;
 910     else if (newpriority > 15) newpriority = 15;
 911
 912     pTask->priority = newpriority + 1;
 913     TASK_UnlinkTask( hTask );
 914     TASK_LinkTask( hTask );
 915     pTask->priority--;
 916 }
 917
 918
 919 /***********************************************************************
 920  *           LockCurrentTask  (KERNEL.33)
 921  */
 922 HTASK LockCurrentTask( BOOL bLock )
 923 {
 924     if (bLock) hLockedTask = hCurrentTask;
 925     else hLockedTask = 0;
 926     return hLockedTask;
 927 }
 928
 929
 930 /***********************************************************************
 931  *           IsTaskLocked  (KERNEL.122)
 932  */
 933 HTASK IsTaskLocked(void)
 934 {
 935     return hLockedTask;
 936 }
 937
 938
 939 /***********************************************************************
 940  *           OldYield  (KERNEL.117)
 941  */
 942 void OldYield(void)
 943 {
 944     TDB *pCurTask;
 945
 946     pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 947     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 948     TASK_YieldToSystem(pCurTask);
 949     if (pCurTask) pCurTask->nEvents--;
 950 }
 951
 952
 953 /***********************************************************************
 954  *           DirectedYield  (KERNEL.150)
 955  */
 956 void DirectedYield( HTASK hTask )
 957 {
 958     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 959     pCurTask->hYieldTo = hTask;
 960     OldYield();
 961 }
 962
 963
 964 /***********************************************************************
 965  *           UserYield  (USER.332)
 966  */
 967 void UserYield(void)
 968 {
 969     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 970     MESSAGEQUEUE *queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 971     /* Handle sent messages */
 972     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
 973         QUEUE_ReceiveMessage( queue );
 974
 975     OldYield();
 976
 977     queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 978     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
 979         QUEUE_ReceiveMessage( queue );
 980 }
 981
 982
 983 /***********************************************************************
 984  *           Yield  (KERNEL.29)
 985  */
 986 void Yield(void)
 987 {
 988     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 989     if (pCurTask) pCurTask->hYieldTo = 0;
 990     if (pCurTask && pCurTask->hQueue) UserYield();
 991     else OldYield();
 992 }
 993
 994
 995 /***********************************************************************
 996  *           MakeProcInstance16  (KERNEL.51)
 997  */
 998 FARPROC16 MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 999 {
1000 #ifdef WINELIB
1001     return func; /* func can be called directly in Winelib */
1002 #else
1003     BYTE *thunk;
1004     SEGPTR thunkaddr;
1005
1006     thunkaddr = TASK_AllocThunk( hCurrentTask );
1007     if (!thunkaddr) return (FARPROC16)0;
1008     thunk = PTR_SEG_TO_LIN( thunkaddr );
1009
1010     dprintf_task( stddeb, "MakeProcInstance(%08lx,%04x): got thunk %08lx\n",
1011                   (DWORD)func, hInstance, (DWORD)thunkaddr );
1012
1013     *thunk++ = 0xb8;    /* movw instance, %ax */
1014     *thunk++ = (BYTE)(hInstance & 0xff);
1015     *thunk++ = (BYTE)(hInstance >> 8);
1016     *thunk++ = 0xea;    /* ljmp func */
1017     *(DWORD *)thunk = (DWORD)func;
1018     return (FARPROC16)thunkaddr;
1019 #endif
1020 }
1021
1022
1023 /***********************************************************************
1024  *           FreeProcInstance16  (KERNEL.52)
1025  */
1026 void FreeProcInstance16( FARPROC16 func )
1027 {
1028 #ifndef WINELIB
1029     dprintf_task( stddeb, "FreeProcInstance(%08lx)\n", (DWORD)func );
1030     TASK_FreeThunk( hCurrentTask, (SEGPTR)func );
1031 #endif
1032 }
1033
1034
1035 /**********************************************************************
1036  *          GetCodeHandle    (KERNEL.93)
1037  */
1038 HANDLE GetCodeHandle( FARPROC16 proc )
1039 {
1040 #ifndef WINELIB32
1041     HANDLE handle;
1042     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
1043
1044     /* Return the code segment containing 'proc'. */
1045     /* Not sure if this is really correct (shouldn't matter that much). */
1046
1047     /* Check if it is really a thunk */
1048     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1049         handle = GlobalHandle16( thunk[6] + (thunk[7] << 8) );
1050     else
1051         handle = GlobalHandle16( HIWORD(proc) );
1052
1053     return handle;
1054 #else
1055     return (HANDLE)proc;
1056 #endif
1057 }
1058
1059
1060 /***********************************************************************
1061  *           SetTaskQueue  (KERNEL.34)
1062  */
1063 HQUEUE16 SetTaskQueue( HTASK16 hTask, HQUEUE16 hQueue )
1064 {
1065     HQUEUE16 hPrev;
1066     TDB *pTask;
1067
1068     if (!hTask) hTask = hCurrentTask;
1069     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1070
1071     hPrev = pTask->hQueue;
1072     pTask->hQueue = hQueue;
1073
1074     TIMER_SwitchQueue( hPrev, hQueue );
1075
1076     return hPrev;
1077 }
1078
1079
1080 /***********************************************************************
1081  *           GetTaskQueue  (KERNEL.35)
1082  */
1083 HQUEUE16 GetTaskQueue( HTASK16 hTask )
1084 {
1085     TDB *pTask;
1086
1087     if (!hTask) hTask = hCurrentTask;
1088     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1089     return pTask->hQueue;
1090 }
1091
1092
1093 /***********************************************************************
1094  *           SwitchStackTo   (KERNEL.108)
1095  */
1096 void SwitchStackTo( WORD seg, WORD ptr, WORD top )
1097 {
1098     TDB *pTask;
1099     STACK16FRAME *oldFrame, *newFrame;
1100     INSTANCEDATA *pData;
1101     UINT16 copySize;
1102
1103     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
1104     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
1105     dprintf_task( stddeb, "SwitchStackTo: old=%04x:%04x new=%04x:%04x\n",
1106                   IF1632_Saved16_ss, IF1632_Saved16_sp, seg, ptr );
1107
1108     /* Save the old stack */
1109
1110     oldFrame           = CURRENT_STACK16;
1111     pData->old_sp      = IF1632_Saved16_sp;
1112     pData->old_ss      = IF1632_Saved16_ss;
1113     pData->stacktop    = top;
1114     pData->stackmin    = ptr;
1115     pData->stackbottom = ptr;
1116
1117     /* Switch to the new stack */
1118
1119     IF1632_Saved16_ss = pTask->ss = seg;
1120     IF1632_Saved16_sp = pTask->sp = ptr - sizeof(STACK16FRAME);
1121     newFrame = CURRENT_STACK16;
1122
1123     /* Copy the stack frame and the local variables to the new stack */
1124
1125     copySize = oldFrame->bp - pData->old_sp;
1126     memcpy( newFrame, oldFrame, MAX( copySize, sizeof(STACK16FRAME) ));
1127 }
1128
1129
1130 /***********************************************************************
1131  *           SwitchStackBack   (KERNEL.109)
1132  *
1133  * Note: the function is declared as 'register' in the spec file in order
1134  * to make sure all registers are preserved, but we don't use them in any
1135  * way, so we don't need a SIGCONTEXT* argument.
1136  */
1137 void SwitchStackBack(void)
1138 {
1139     TDB *pTask;
1140     STACK16FRAME *oldFrame, *newFrame;
1141     INSTANCEDATA *pData;
1142
1143     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
1144     if (!(pData = (INSTANCEDATA *)GlobalLock16( IF1632_Saved16_ss ))) return;
1145     if (!pData->old_ss)
1146     {
1147         fprintf( stderr, "SwitchStackBack: no previous SwitchStackTo\n" );
1148         return;
1149     }
1150     dprintf_task( stddeb, "SwitchStackBack: restoring stack %04x:%04x\n",
1151                   pData->old_ss, pData->old_sp );
1152
1153     oldFrame = CURRENT_STACK16;
1154
1155     /* Switch back to the old stack */
1156
1157     IF1632_Saved16_ss = pTask->ss = pData->old_ss;
1158     IF1632_Saved16_sp = pTask->sp = pData->old_sp;
1159     pData->old_ss = pData->old_sp = 0;
1160
1161     /* Build a stack frame for the return */
1162
1163     newFrame = CURRENT_STACK16;
1164     newFrame->saved_ss = oldFrame->saved_ss;
1165     newFrame->saved_sp = oldFrame->saved_sp;
1166     newFrame->entry_ip = oldFrame->entry_ip;
1167     newFrame->entry_cs = oldFrame->entry_cs;
1168     newFrame->bp       = oldFrame->bp;
1169     newFrame->ip       = oldFrame->ip;
1170     newFrame->cs       = oldFrame->cs;
1171 }
1172
1173
1174 /***********************************************************************
1175  *           GetTaskQueueDS  (KERNEL.118)
1176  */
1177 #ifndef WINELIB
1178 void GetTaskQueueDS( SIGCONTEXT *context )
1179 {
1180     DS_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1181 }
1182 #endif  /* WINELIB */
1183
1184
1185 /***********************************************************************
1186  *           GetTaskQueueES  (KERNEL.119)
1187  */
1188 #ifndef WINELIB
1189 void GetTaskQueueES( SIGCONTEXT *context )
1190 {
1191     ES_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1192 }
1193 #endif  /* WINELIB */
1194
1195
1196 /***********************************************************************
1197  *           GetCurrentTask   (KERNEL.36)
1198  */
1199 HTASK16 GetCurrentTask(void)
1200 {
1201     return hCurrentTask;
1202 }
1203
1204 DWORD WIN16_GetCurrentTask(void)
1205 {
1206     /* This is the version used by relay code; the first task is */
1207     /* returned in the high word of the result */
1208     return MAKELONG( hCurrentTask, hFirstTask );
1209 }
1210
1211
1212 /***********************************************************************
1213  *           GetCurrentPDB   (KERNEL.37)
1214  */
1215 HANDLE16 GetCurrentPDB(void)
1216 {
1217     TDB *pTask;
1218
1219     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1220     return pTask->hPDB;
1221 }
1222
1223
1224 /***********************************************************************
1225  *           GetInstanceData   (KERNEL.54)
1226  */
1227 int GetInstanceData( HANDLE instance, WORD buffer, int len )
1228 {
1229     char *ptr = (char *)GlobalLock16( instance );
1230     if (!ptr || !len) return 0;
1231     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1232     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1233     return len;
1234 }
1235
1236
1237 /***********************************************************************
1238  *           GetExeVersion   (KERNEL.105)
1239  */
1240 WORD GetExeVersion(void)
1241 {
1242     TDB *pTask;
1243
1244     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1245     return pTask->version;
1246 }
1247
1248
1249 /***********************************************************************
1250  *           SetErrorMode   (KERNEL.107)
1251  */
1252 UINT SetErrorMode( UINT mode )
1253 {
1254     TDB *pTask;
1255     UINT oldMode;
1256
1257     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1258     oldMode = pTask->error_mode;
1259     pTask->error_mode = mode;
1260     return oldMode;
1261 }
1262
1263
1264 /***********************************************************************
1265  *           GetDOSEnvironment   (KERNEL.131)
1266  */
1267 SEGPTR GetDOSEnvironment(void)
1268 {
1269     TDB *pTask;
1270
1271     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1272     return (SEGPTR)WIN16_GlobalLock16( pTask->pdb.environment );
1273 }
1274
1275
1276 /***********************************************************************
1277  *           GetNumTasks   (KERNEL.152)
1278  */
1279 WORD GetNumTasks(void)
1280 {
1281     return nTaskCount;
1282 }
1283
1284
1285 /***********************************************************************
1286  *           GetTaskDS   (KERNEL.155)
1287  *
1288  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1289  * I don't think we need to bother with this.
1290  */
1291 HINSTANCE16 GetTaskDS(void)
1292 {
1293     TDB *pTask;
1294
1295     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1296     return pTask->hInstance;
1297 }
1298
1299
1300 /***********************************************************************
1301  *           IsTask   (KERNEL.320)
1302  */
1303 BOOL IsTask( HTASK hTask )
1304 {
1305     TDB *pTask;
1306
1307     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1308     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1309     return (pTask->magic == TDB_MAGIC);
1310 }
1311
1312
1313 /***********************************************************************
1314  *           SetTaskSignalProc   (KERNEL.38)
1315  */
1316 FARPROC16 SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1317 {
1318     TDB *pTask;
1319     FARPROC16 oldProc;
1320
1321     if (!hTask) hTask = hCurrentTask;
1322     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return NULL;
1323     oldProc = pTask->userhandler;
1324     pTask->userhandler = proc;
1325     return oldProc;
1326 }
1327
1328
1329 /***********************************************************************
1330  *           SetSigHandler   (KERNEL.140)
1331  */
1332 WORD SetSigHandler( FARPROC16 newhandler, FARPROC16* oldhandler,
1333                     UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1334 {
1335     fprintf(stdnimp,"SetSigHandler(%p,%p,%p,%d,%d), unimplemented.\n",
1336             newhandler,oldhandler,oldmode,newmode,flag );
1337
1338     if (flag != 1) return 0;
1339     if (!newmode) newhandler = NULL;  /* Default handler */
1340     if (newmode != 4)
1341     {
1342         TDB *pTask;
1343
1344         if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1345         if (oldmode) *oldmode = pTask->signal_flags;
1346         pTask->signal_flags = newmode;
1347         if (oldhandler) *oldhandler = pTask->sighandler;
1348         pTask->sighandler = newhandler;
1349     }
1350     return 0;
1351 }
1352
1353
1354 /***********************************************************************
1355  *           GetExePtr   (KERNEL.133)
1356  */
1357 HMODULE16 GetExePtr( HANDLE16 handle )
1358 {
1359     char *ptr;
1360     HTASK16 hTask;
1361     HANDLE16 owner;
1362
1363       /* Check for module handle */
1364
1365     if (!(ptr = GlobalLock16( handle ))) return 0;
1366     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return handle;
1367
1368       /* Check the owner for module handle */
1369
1370     owner = FarGetOwner( handle );
1371     if (!(ptr = GlobalLock16( owner ))) return 0;
1372     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return owner;
1373
1374       /* Search for this handle and its owner inside all tasks */
1375
1376     hTask = hFirstTask;
1377     while (hTask)
1378     {
1379         TDB *pTask = (TDB *)GlobalLock16( hTask );
1380         if ((hTask == handle) ||
1381             (pTask->hInstance == handle) ||
1382             (pTask->hQueue == handle) ||
1383             (pTask->hPDB == handle)) return pTask->hModule;
1384         if ((hTask == owner) ||
1385             (pTask->hInstance == owner) ||
1386             (pTask->hQueue == owner) ||
1387             (pTask->hPDB == owner)) return pTask->hModule;
1388         hTask = pTask->hNext;
1389     }
1390     return 0;
1391 }
1392
1393
1394 /***********************************************************************
1395  *           TaskFirst   (TOOLHELP.63)
1396  */
1397 BOOL16 TaskFirst( TASKENTRY *lpte )
1398 {
1399     lpte->hNext = hFirstTask;
1400     return TaskNext( lpte );
1401 }
1402
1403
1404 /***********************************************************************
1405  *           TaskNext   (TOOLHELP.64)
1406  */
1407 BOOL16 TaskNext( TASKENTRY *lpte )
1408 {
1409     TDB *pTask;
1410     INSTANCEDATA *pInstData;
1411
1412     dprintf_toolhelp( stddeb, "TaskNext(%p): task=%04x\n", lpte, lpte->hNext );
1413     if (!lpte->hNext) return FALSE;
1414     pTask = (TDB *)GlobalLock16( lpte->hNext );
1415     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1416     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1417     lpte->hTask         = lpte->hNext;
1418     lpte->hTaskParent   = pTask->hParent;
1419     lpte->hInst         = pTask->hInstance;
1420     lpte->hModule       = pTask->hModule;
1421     lpte->wSS           = pTask->ss;
1422     lpte->wSP           = pTask->sp;
1423     lpte->wStackTop     = pInstData->stacktop;
1424     lpte->wStackMinimum = pInstData->stackmin;
1425     lpte->wStackBottom  = pInstData->stackbottom;
1426     lpte->wcEvents      = pTask->nEvents;
1427     lpte->hQueue        = pTask->hQueue;
1428     strncpy( lpte->szModule, pTask->module_name, 8 );
1429     lpte->szModule[8]   = '\0';
1430     lpte->wPSPOffset    = 0x100;  /*??*/
1431     lpte->hNext         = pTask->hNext;
1432     return TRUE;
1433 }
1434
1435
1436 /***********************************************************************
1437  *           TaskFindHandle   (TOOLHELP.65)
1438  */
1439 BOOL16 TaskFindHandle( TASKENTRY *lpte, HTASK16 hTask )
1440 {
1441     lpte->hNext = hTask;
1442     return TaskNext( lpte );
1443 }
1444
1445
1446 /***********************************************************************
1447  *           GetAppCompatFlags   (KERNEL.354) (USER32.205)
1448  */
1449 DWORD GetAppCompatFlags( HTASK32 hTask )
1450 {
1451     TDB *pTask;
1452
1453     if (!hTask) hTask = GetCurrentTask();
1454     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1455     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1456     return pTask->compat_flags;
1457 }