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 UINT16 nTaskCount = 0;
  58 static HGLOBAL16 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 HGLOBAL16 TASK_CreateDOSEnvironment(void);
  70 static void      TASK_YieldToSystem(TDB*);
  71
  72 /***********************************************************************
  73  *           TASK_Init
  74  */
  75 BOOL32 TASK_Init(void)
  76 {
  77     TASK_RescheduleProc = MODULE_GetWndProcEntry16( "TASK_Reschedule" );
  78     if (!(hDOSEnvironment = TASK_CreateDOSEnvironment()))
  79         fprintf( stderr, "Not enough memory for DOS Environment\n" );
  80     return (hDOSEnvironment != 0);
  81 }
  82
  83
  84 /***********************************************************************
  85  *           TASK_GetNextTask
  86  */
  87 HTASK16 TASK_GetNextTask( HTASK16 hTask )
  88 {
  89     TDB* pTask = (TDB*)GlobalLock16(hTask);
  90
  91     if (pTask->hNext) return pTask->hNext;
  92     return (hFirstTask != hTask) ? hFirstTask : 0;
  93 }
  94
  95
  96 /***********************************************************************
  97  *           TASK_CreateDOSEnvironment
  98  *
  99  * Create the original DOS environment.
 100  */
 101 static HGLOBAL16 TASK_CreateDOSEnvironment(void)
 102 {
 103     static const char program_name[] = "KRNL386.EXE";
 104     char **e, *p;
 105     int initial_size, size, i, winpathlen, sysdirlen;
 106     HGLOBAL16 handle;
 107
 108     extern char **environ;
 109
 110     /* DOS environment format:
 111      * ASCIIZ   string 1
 112      * ASCIIZ   string 2
 113      * ...
 114      * ASCIIZ   string n
 115      * ASCIIZ   PATH=xxx
 116      * BYTE     0
 117      * WORD     1
 118      * ASCIIZ   program name (e.g. C:\WINDOWS\SYSTEM\KRNL386.EXE)
 119      */
 120
 121     /* First compute the size of the fixed part of the environment */
 122
 123     for (i = winpathlen = 0; ; i++)
 124     {
 125         int len = DIR_GetDosPath( i, NULL, 0 );
 126         if (!len) break;
 127         winpathlen += len + 1;
 128     }
 129     if (!winpathlen) winpathlen = 1;
 130     sysdirlen  = GetSystemDirectory32A( NULL, 0 ) + 1;
 131     initial_size = 5 + winpathlen +           /* PATH=xxxx */
 132                    1 +                        /* BYTE 0 at end */
 133                    sizeof(WORD) +             /* WORD 1 */
 134                    sysdirlen +                /* program directory */
 135                    strlen(program_name) + 1;  /* program name */
 136
 137     /* Compute the total size of the Unix environment (except path) */
 138
 139     for (e = environ, size = initial_size; *e; e++)
 140     {
 141         if (lstrncmpi32A(*e, "path=", 5))
 142         {
 143             int len = strlen(*e) + 1;
 144             if (size + len >= 32767)
 145             {
 146                 fprintf( stderr, "Warning: environment larger than 32k.\n" );
 147                 break;
 148             }
 149             size += len;
 150         }
 151     }
 152
 153
 154     /* Now allocate the environment */
 155
 156     if (!(handle = GlobalAlloc16( GMEM_FIXED, size ))) return 0;
 157     p = (char *)GlobalLock16( handle );
 158
 159     /* And fill it with the Unix environment */
 160
 161     for (e = environ, size = initial_size; *e; e++)
 162     {
 163         if (lstrncmpi32A(*e, "path=", 5))
 164         {
 165             int len = strlen(*e) + 1;
 166             if (size + len >= 32767) break;
 167             strcpy( p, *e );
 168             size += len;
 169             p    += len;
 170         }
 171     }
 172
 173     /* Now add the path */
 174
 175     strcpy( p, "PATH=" );
 176     for (i = 0, p += 5; ; i++)
 177     {
 178         if (!DIR_GetDosPath( i, p, winpathlen )) break;
 179         p += strlen(p);
 180         *p++ = ';';
 181     }
 182     if (p[-1] == ';') p[-1] = '\0';
 183     else p++;
 184
 185     /* Now add the program name */
 186
 187     *p++ = '\0';
 188     PUT_WORD( p, 1 );
 189     p += sizeof(WORD);
 190     GetSystemDirectory32A( p, sysdirlen );
 191     strcat( p, "\\" );
 192     strcat( p, program_name );
 193
 194     /* Display it */
 195
 196     p = (char *) GlobalLock16( handle );
 197     dprintf_task(stddeb, "Master DOS environment at %p\n", p);
 198     for (; *p; p += strlen(p) + 1) dprintf_task(stddeb, "    %s\n", p);
 199     dprintf_task( stddeb, "Progname: %s\n", p+3 );
 200
 201     return handle;
 202 }
 203
 204
 205 /***********************************************************************
 206  *           TASK_LinkTask
 207  */
 208 static void TASK_LinkTask( HTASK16 hTask )
 209 {
 210     HTASK16 *prevTask;
 211     TDB *pTask;
 212
 213     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 214     prevTask = &hFirstTask;
 215     while (*prevTask)
 216     {
 217         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
 218         if (prevTaskPtr->priority >= pTask->priority) break;
 219         prevTask = &prevTaskPtr->hNext;
 220     }
 221     pTask->hNext = *prevTask;
 222     *prevTask = hTask;
 223     nTaskCount++;
 224 }
 225
 226
 227 /***********************************************************************
 228  *           TASK_UnlinkTask
 229  */
 230 static void TASK_UnlinkTask( HTASK16 hTask )
 231 {
 232     HTASK16 *prevTask;
 233     TDB *pTask;
 234
 235     prevTask = &hFirstTask;
 236     while (*prevTask && (*prevTask != hTask))
 237     {
 238         pTask = (TDB *)GlobalLock16( *prevTask );
 239         prevTask = &pTask->hNext;
 240     }
 241     if (*prevTask)
 242     {
 243         pTask = (TDB *)GlobalLock16( *prevTask );
 244         *prevTask = pTask->hNext;
 245         pTask->hNext = 0;
 246         nTaskCount--;
 247     }
 248 }
 249
 250
 251 /***********************************************************************
 252  *           TASK_CreateThunks
 253  *
 254  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 255  * and containing 'count' entries.
 256  */
 257 static void TASK_CreateThunks( HGLOBAL16 handle, WORD offset, WORD count )
 258 {
 259     int i;
 260     WORD free;
 261     THUNKS *pThunk;
 262
 263     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 264     pThunk->next = 0;
 265     pThunk->magic = THUNK_MAGIC;
 266     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 267     free = pThunk->free;
 268     for (i = 0; i < count-1; i++)
 269     {
 270         free += 8;  /* Offset of next thunk */
 271         pThunk->thunks[4*i] = free;
 272     }
 273     pThunk->thunks[4*i] = 0;  /* Last thunk */
 274 }
 275
 276
 277 /***********************************************************************
 278  *           TASK_AllocThunk
 279  *
 280  * Allocate a thunk for MakeProcInstance().
 281  */
 282 #ifndef WINELIB32
 283 static SEGPTR TASK_AllocThunk( HTASK16 hTask )
 284 {
 285     TDB *pTask;
 286     THUNKS *pThunk;
 287     WORD sel, base;
 288
 289     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 290     sel = pTask->hCSAlias;
 291     pThunk = &pTask->thunks;
 292     base = (int)pThunk - (int)pTask;
 293     while (!pThunk->free)
 294     {
 295         sel = pThunk->next;
 296         if (!sel)  /* Allocate a new segment */
 297         {
 298             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 299                                 pTask->hPDB, TRUE, FALSE, FALSE );
 300             if (!sel) return (SEGPTR)0;
 301             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 302             pThunk->next = sel;
 303         }
 304         pThunk = (THUNKS *)GlobalLock16( sel );
 305         base = 0;
 306     }
 307     base += pThunk->free;
 308     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 309     return PTR_SEG_OFF_TO_SEGPTR( sel, base );
 310 }
 311 #endif
 312
 313
 314 /***********************************************************************
 315  *           TASK_FreeThunk
 316  *
 317  * Free a MakeProcInstance() thunk.
 318  */
 319 #ifndef WINELIB32
 320 static BOOL TASK_FreeThunk( HTASK16 hTask, SEGPTR thunk )
 321 {
 322     TDB *pTask;
 323     THUNKS *pThunk;
 324     WORD sel, base;
 325
 326     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 327     sel = pTask->hCSAlias;
 328     pThunk = &pTask->thunks;
 329     base = (int)pThunk - (int)pTask;
 330     while (sel && (sel != HIWORD(thunk)))
 331     {
 332         sel = pThunk->next;
 333         pThunk = (THUNKS *)GlobalLock16( sel );
 334         base = 0;
 335     }
 336     if (!sel) return FALSE;
 337     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 338     pThunk->free = LOWORD(thunk) - base;
 339     return TRUE;
 340 }
 341 #endif
 342
 343
 344 /***********************************************************************
 345  *           TASK_CallToStart
 346  *
 347  * 32-bit entry point for a new task. This function is responsible for
 348  * setting up the registers and jumping to the 16-bit entry point.
 349  */
 350 #ifndef WINELIB
 351 static void TASK_CallToStart(void)
 352 {
 353     int cs_reg, ds_reg, fs_reg, ip_reg;
 354     int exit_code = 1;
 355     TDB *pTask = (TDB *)GlobalLock16( hCurrentTask );
 356     NE_MODULE *pModule = MODULE_GetPtr( pTask->hModule );
 357     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 358
 359     IF1632_Saved16_ss = pTask->ss;
 360     IF1632_Saved16_sp = pTask->sp;
 361
 362     if (pModule->flags & NE_FFLAGS_WIN32)
 363     {
 364         /* FIXME: all this is an ugly hack */
 365
 366         extern void PE_InitTEB( int hTEB );
 367         extern void InitTask( SIGCONTEXT *context );
 368         extern void PE_InitializeDLLs( HMODULE16 hModule );
 369
 370         InitTask( NULL );
 371         InitApp( pTask->hModule );
 372         fs_reg = (int)GlobalAlloc16( GMEM_FIXED | GMEM_ZEROINIT, 0x10000 );
 373         PE_InitTEB( fs_reg );
 374         __asm__ __volatile__("movw %w0,%%fs"::"r" (fs_reg));
 375         PE_InitializeDLLs( pTask->hModule );
 376         exit_code = CallTaskStart32((FARPROC32)(pModule->pe_module->load_addr +
 377                 pModule->pe_module->pe_header->opt_coff.AddressOfEntryPoint) );
 378         TASK_KillCurrentTask( exit_code );
 379     }
 380     else
 381     {
 382         /* Registers at initialization must be:
 383          * ax   zero
 384          * bx   stack size in bytes
 385          * cx   heap size in bytes
 386          * si   previous app instance
 387          * di   current app instance
 388          * bp   zero
 389          * es   selector to the PSP
 390          * ds   dgroup of the application
 391          * ss   stack selector
 392          * sp   top of the stack
 393          */
 394
 395         cs_reg = pSegTable[pModule->cs - 1].selector;
 396         ip_reg = pModule->ip;
 397         ds_reg = pSegTable[pModule->dgroup - 1].selector;
 398
 399         dprintf_task( stddeb, "Starting main program: cs:ip=%04x:%04x ds=%04x ss:sp=%04x:%04x\n",
 400                       cs_reg, ip_reg, ds_reg,
 401                       IF1632_Saved16_ss, IF1632_Saved16_sp);
 402
 403         CallTo16_regs_( (FARPROC16)(cs_reg << 16 | ip_reg), ds_reg,
 404                         pTask->hPDB /*es*/, 0 /*bp*/, 0 /*ax*/,
 405                         pModule->stack_size /*bx*/, pModule->heap_size /*cx*/,
 406                         0 /*dx*/, 0 /*si*/, ds_reg /*di*/ );
 407         /* This should never return */
 408         fprintf( stderr, "TASK_CallToStart: Main program returned!\n" );
 409         TASK_KillCurrentTask( 1 );
 410     }
 411 }
 412 #endif
 413
 414
 415 /***********************************************************************
 416  *           TASK_CreateTask
 417  */
 418 HTASK16 TASK_CreateTask( HMODULE16 hModule, HINSTANCE16 hInstance,
 419                          HINSTANCE16 hPrevInstance, HANDLE16 hEnvironment,
 420                          LPCSTR cmdLine, UINT16 cmdShow )
 421 {
 422     HTASK16 hTask;
 423     TDB *pTask;
 424     HGLOBAL16 hParentEnv;
 425     NE_MODULE *pModule;
 426     SEGTABLEENTRY *pSegTable;
 427     LPSTR name;
 428     char filename[256];
 429     char *stack16Top, *stack32Top;
 430     STACK16FRAME *frame16;
 431     STACK32FRAME *frame32;
 432 #ifndef WINELIB32
 433     extern DWORD CALLTO16_RetAddr_word;
 434 #endif
 435
 436     if (!(pModule = MODULE_GetPtr( hModule ))) return 0;
 437     pSegTable = NE_SEG_TABLE( pModule );
 438
 439       /* Allocate the task structure */
 440
 441     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 442                           hModule, FALSE, FALSE, FALSE );
 443     if (!hTask) return 0;
 444     pTask = (TDB *)GlobalLock16( hTask );
 445
 446       /* Allocate the new environment block */
 447
 448     if (!(hParentEnv = hEnvironment))
 449     {
 450         TDB *pParent = (TDB *)GlobalLock16( hCurrentTask );
 451         hParentEnv = pParent ? pParent->pdb.environment : hDOSEnvironment;
 452     }
 453     /* FIXME: do we really need to make a copy also when */
 454     /*        we don't use the parent environment? */
 455     if (!(hEnvironment = GlobalAlloc16( GMEM_FIXED, GlobalSize16(hParentEnv))))
 456     {
 457         GlobalFree16( hTask );
 458         return 0;
 459     }
 460     memcpy( GlobalLock16( hEnvironment ), GlobalLock16( hParentEnv ),
 461             GlobalSize16( hParentEnv ) );
 462
 463       /* Get current directory */
 464
 465     GetModuleFileName16( hModule, filename, sizeof(filename) );
 466     name = strrchr(filename, '\\');
 467     if (name) *(name+1) = 0;
 468
 469       /* Fill the task structure */
 470
 471     pTask->nEvents       = 1;  /* So the task can be started */
 472     pTask->hSelf         = hTask;
 473     pTask->flags         = 0;
 474
 475     if (pModule->flags & NE_FFLAGS_WIN32)
 476         pTask->flags    |= TDBF_WIN32;
 477
 478     pTask->version       = pModule->expected_version;
 479     pTask->hInstance     = hInstance;
 480     pTask->hPrevInstance = hPrevInstance;
 481     pTask->hModule       = hModule;
 482     pTask->hParent       = hCurrentTask;
 483     pTask->curdrive      = filename[0] - 'A' + 0x80;
 484     strcpy( pTask->curdir, filename+2 );
 485     pTask->magic         = TDB_MAGIC;
 486     pTask->nCmdShow      = cmdShow;
 487
 488       /* Create the thunks block */
 489
 490     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 491
 492       /* Copy the module name */
 493
 494     name = MODULE_GetModuleName( hModule );
 495     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 496
 497       /* Allocate a selector for the PDB */
 498
 499     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB),
 500                                       hModule, FALSE, FALSE, FALSE, NULL );
 501
 502       /* Fill the PDB */
 503
 504     pTask->pdb.int20 = 0x20cd;
 505     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 506 #ifndef WINELIB
 507     *(FARPROC16 *)&pTask->pdb.dispatcher[1] = MODULE_GetEntryPoint( GetModuleHandle("KERNEL"), 102 );  /* KERNEL.102 is DOS3Call() */
 508     pTask->pdb.savedint22 = INT_GetHandler( 0x22 );
 509     pTask->pdb.savedint23 = INT_GetHandler( 0x23 );
 510     pTask->pdb.savedint24 = INT_GetHandler( 0x24 );
 511 #endif
 512     pTask->pdb.fileHandlesPtr =
 513         PTR_SEG_OFF_TO_SEGPTR( GlobalHandleToSel(pTask->hPDB),
 514                                (int)&((PDB *)0)->fileHandles );
 515     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 516     pTask->pdb.environment    = hEnvironment;
 517     pTask->pdb.nbFiles        = 20;
 518     lstrcpyn32A( pTask->pdb.cmdLine + 1, cmdLine, 127 );
 519     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 520
 521       /* Get the compatibility flags */
 522
 523     pTask->compat_flags = GetProfileInt32A( "Compatibility", name, 0 );
 524
 525       /* Allocate a code segment alias for the TDB */
 526
 527     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 528                                           sizeof(TDB), pTask->hPDB, TRUE,
 529                                           FALSE, FALSE, NULL );
 530
 531       /* Set the owner of the environment block */
 532
 533     FarSetOwner( pTask->pdb.environment, pTask->hPDB );
 534
 535       /* Default DTA overwrites command-line */
 536
 537     pTask->dta = PTR_SEG_OFF_TO_SEGPTR( pTask->hPDB,
 538                                 (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 539
 540       /* Allocate the 32-bit stack */
 541
 542     pTask->hStack32 = GLOBAL_Alloc( GMEM_FIXED, STACK32_SIZE, pTask->hPDB,
 543                                     FALSE, FALSE, FALSE );
 544
 545       /* Create the 32-bit stack frame */
 546
 547     *(DWORD *)GlobalLock16(pTask->hStack32) = 0xDEADBEEF;
 548     stack32Top = (char*)GlobalLock16(pTask->hStack32) + STACK32_SIZE;
 549     frame32 = (STACK32FRAME *)stack32Top - 1;
 550     frame32->saved_esp = (DWORD)stack32Top;
 551     frame32->edi = 0;
 552     frame32->esi = 0;
 553     frame32->edx = 0;
 554     frame32->ecx = 0;
 555     frame32->ebx = 0;
 556     frame32->ebp = 0;
 557 #ifndef WINELIB
 558     frame32->retaddr = (DWORD)TASK_CallToStart;
 559     frame32->codeselector = WINE_CODE_SELECTOR;
 560 #endif
 561     pTask->esp = (DWORD)frame32;
 562
 563       /* Create the 16-bit stack frame */
 564
 565     pTask->ss = hInstance;
 566     pTask->sp = ((pModule->sp != 0) ? pModule->sp :
 567                  pSegTable[pModule->ss-1].minsize + pModule->stack_size) & ~1;
 568     stack16Top = (char *)PTR_SEG_OFF_TO_LIN( pTask->ss, pTask->sp );
 569     frame16 = (STACK16FRAME *)stack16Top - 1;
 570     frame16->saved_ss = 0;
 571     frame16->saved_sp = 0;
 572     frame16->ds = frame16->es = pTask->hInstance;
 573     frame16->entry_point = 0;
 574     frame16->entry_ip = OFFSETOF(TASK_RescheduleProc) + 14;
 575     frame16->entry_cs = SELECTOROF(TASK_RescheduleProc);
 576     frame16->bp = 0;
 577 #ifndef WINELIB
 578     frame16->ip = LOWORD( CALLTO16_RetAddr_word );
 579     frame16->cs = HIWORD( CALLTO16_RetAddr_word );
 580 #endif  /* WINELIB */
 581     pTask->sp -= sizeof(STACK16FRAME);
 582
 583       /* If there's no 16-bit stack yet, use a part of the new task stack */
 584       /* This is only needed to have a stack to switch from on the first  */
 585       /* call to DirectedYield(). */
 586
 587     if (!IF1632_Saved16_ss)
 588     {
 589         IF1632_Saved16_ss = pTask->ss;
 590         IF1632_Saved16_sp = pTask->sp;
 591     }
 592
 593       /* Add a breakpoint at the start of the task */
 594
 595 #ifndef WINELIB
 596     if (Options.debug)
 597     {
 598         if (pModule->flags & NE_FFLAGS_WIN32)
 599         {
 600             DBG_ADDR addr = { 0, pModule->pe_module->load_addr +
 601                               pModule->pe_module->pe_header->opt_coff.AddressOfEntryPoint };
 602             fprintf( stderr, "Win32 task '%s': ", name );
 603             DEBUG_AddBreakpoint( &addr );
 604         }
 605         else
 606         {
 607             DBG_ADDR addr = { pSegTable[pModule->cs-1].selector, pModule->ip };
 608             fprintf( stderr, "Win16 task '%s': ", name );
 609             DEBUG_AddBreakpoint( &addr );
 610         }
 611     }
 612 #endif  /* WINELIB */
 613
 614       /* Add the task to the linked list */
 615
 616     TASK_LinkTask( hTask );
 617
 618     dprintf_task( stddeb, "CreateTask: module='%s' cmdline='%s' task=%04x\n",
 619                   name, cmdLine, hTask );
 620
 621     return hTask;
 622 }
 623
 624
 625 /***********************************************************************
 626  *           TASK_DeleteTask
 627  */
 628 static void TASK_DeleteTask( HTASK16 hTask )
 629 {
 630     TDB *pTask;
 631     HGLOBAL16 hPDB;
 632
 633     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 634     hPDB = pTask->hPDB;
 635
 636     /* Free the task module */
 637
 638     FreeModule16( pTask->hModule );
 639
 640     /* Close all open files of this task */
 641
 642     FILE_CloseAllFiles( pTask->hPDB );
 643
 644     /* Free the selector aliases */
 645
 646     GLOBAL_FreeBlock( pTask->hCSAlias );
 647     GLOBAL_FreeBlock( pTask->hPDB );
 648
 649     /* Free the task structure itself */
 650
 651     GlobalFree16( hTask );
 652
 653     /* Free all memory used by this task (including the 32-bit stack, */
 654     /* the environment block and the thunk segments). */
 655
 656     GlobalFreeAll( hPDB );
 657 }
 658
 659
 660 /***********************************************************************
 661  *           TASK_KillCurrentTask
 662  *
 663  * Kill the currently running task. As it's not possible to kill the
 664  * current task like this, it is simply marked for destruction, and will
 665  * be killed when either TASK_Reschedule or this function is called again
 666  * in the context of another task.
 667  */
 668 void TASK_KillCurrentTask( INT16 exitCode )
 669 {
 670     extern void EXEC_ExitWindows( int retCode );
 671
 672     TDB* pTask = (TDB*) GlobalLock16( hCurrentTask );
 673     if (!pTask) EXEC_ExitWindows(0);  /* No current task yet */
 674
 675     /* Perform USER cleanup */
 676
 677     USER_AppExit( hCurrentTask, pTask->hInstance, pTask->hQueue );
 678
 679     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 680     {
 681         /* If another task is already marked for destruction, */
 682         /* we can kill it now, as we are in another context.  */
 683         TASK_DeleteTask( hTaskToKill );
 684     }
 685
 686     if (nTaskCount <= 1)
 687     {
 688         dprintf_task( stddeb, "Killing the last task, exiting\n" );
 689         EXEC_ExitWindows( 0 );
 690     }
 691
 692     /* Remove the task from the list to be sure we never switch back to it */
 693     TASK_UnlinkTask( hCurrentTask );
 694     if( nTaskCount )
 695     {
 696         TDB* p = (TDB *)GlobalLock16( hFirstTask );
 697         while( p )
 698         {
 699             if( p->hYieldTo == hCurrentTask ) p->hYieldTo = 0;
 700             p = (TDB *)GlobalLock16( p->hNext );
 701         }
 702     }
 703
 704     hTaskToKill = hCurrentTask;
 705     hLockedTask = 0;
 706
 707     pTask->nEvents = 0;
 708     TASK_YieldToSystem(pTask);
 709
 710     /* We should never return from this Yield() */
 711
 712     fprintf(stderr,"Return of the living dead %04x!!!\n", hCurrentTask);
 713     exit(1);
 714 }
 715
 716 /***********************************************************************
 717  *           TASK_YieldToSystem
 718  *
 719  * Scheduler interface, this way we ensure that all "unsafe" events are
 720  * processed outside the scheduler.
 721  */
 722 void TASK_YieldToSystem(TDB* pTask)
 723 {
 724   MESSAGEQUEUE*         pQ;
 725
 726   TASK_SCHEDULE();
 727
 728   if( pTask )
 729   {
 730     pQ = (MESSAGEQUEUE*)GlobalLock16(pTask->hQueue);
 731     if( pQ && pQ->flags & QUEUE_FLAG_XEVENT )
 732     {
 733       pQ->flags &= ~QUEUE_FLAG_XEVENT;
 734       EVENT_WaitXEvent( FALSE, FALSE );
 735     }
 736   }
 737 }
 738
 739 /***********************************************************************
 740  *           TASK_Reschedule
 741  *
 742  * This is where all the magic of task-switching happens!
 743  *
 744  * Note: This function should only be called via the TASK_YieldToSystem()
 745  *       wrapper, to make sure that all the context is saved correctly.
 746  *
 747  *       It must not call functions that may yield control.
 748  */
 749 void TASK_Reschedule(void)
 750 {
 751     TDB *pOldTask = NULL, *pNewTask;
 752     HTASK16 hTask = 0;
 753
 754 #ifdef CONFIG_IPC
 755     dde_reschedule();
 756 #endif
 757       /* First check if there's a task to kill */
 758
 759     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 760     {
 761         TASK_DeleteTask( hTaskToKill );
 762         hTaskToKill = 0;
 763     }
 764
 765     /* Find a task to yield to */
 766
 767     pOldTask = (TDB *)GlobalLock16( hCurrentTask );
 768     if (pOldTask && pOldTask->hYieldTo)
 769     {
 770         /* check for DirectedYield() */
 771
 772         hTask = pOldTask->hYieldTo;
 773         pNewTask = (TDB *)GlobalLock16( hTask );
 774         if( !pNewTask || !pNewTask->nEvents) hTask = 0;
 775         pOldTask->hYieldTo = 0;
 776     }
 777
 778     /* extract hardware events only! */
 779
 780     if (!hTask) EVENT_WaitXEvent( FALSE, TRUE );
 781
 782     while (!hTask)
 783     {
 784         /* Find a task that has an event pending */
 785
 786         hTask = hFirstTask;
 787         while (hTask)
 788         {
 789             pNewTask = (TDB *)GlobalLock16( hTask );
 790
 791             dprintf_task( stddeb, "\ttask = %04x, events = %i\n", hTask, pNewTask->nEvents);
 792
 793             if (pNewTask->nEvents) break;
 794             hTask = pNewTask->hNext;
 795         }
 796         if (hLockedTask && (hTask != hLockedTask)) hTask = 0;
 797         if (hTask) break;
 798
 799         /* No task found, wait for some events to come in */
 800
 801         EVENT_WaitXEvent( TRUE, TRUE );
 802     }
 803
 804     if (hTask == hCurrentTask)
 805     {
 806        dprintf_task( stddeb, "returning to the current task(%04x)\n", hTask );
 807        return;  /* Nothing to do */
 808     }
 809     pNewTask = (TDB *)GlobalLock16( hTask );
 810     dprintf_task( stddeb, "Switching to task %04x (%.8s)\n",
 811                   hTask, pNewTask->module_name );
 812
 813       /* Save the stacks of the previous task (if any) */
 814
 815     if (pOldTask)
 816     {
 817         pOldTask->ss  = IF1632_Saved16_ss;
 818         pOldTask->sp  = IF1632_Saved16_sp;
 819         pOldTask->esp = IF1632_Saved32_esp;
 820     }
 821     else IF1632_Original32_esp = IF1632_Saved32_esp;
 822
 823      /* Make the task the last in the linked list (round-robin scheduling) */
 824
 825     pNewTask->priority++;
 826     TASK_UnlinkTask( hTask );
 827     TASK_LinkTask( hTask );
 828     pNewTask->priority--;
 829
 830       /* Switch to the new stack */
 831
 832     hCurrentTask = hTask;
 833     IF1632_Saved16_ss   = pNewTask->ss;
 834     IF1632_Saved16_sp   = pNewTask->sp;
 835     IF1632_Saved32_esp  = pNewTask->esp;
 836     IF1632_Stack32_base = WIN16_GlobalLock16( pNewTask->hStack32 );
 837 }
 838
 839
 840 /***********************************************************************
 841  *           InitTask  (KERNEL.91)
 842  */
 843 #ifdef WINELIB
 844 void InitTask(void)
 845 #else
 846 void InitTask( SIGCONTEXT *context )
 847 #endif
 848 {
 849     TDB *pTask;
 850     NE_MODULE *pModule;
 851     SEGTABLEENTRY *pSegTable;
 852     INSTANCEDATA *pinstance;
 853     LONG stacklow, stackhi;
 854
 855 #ifndef WINELIB
 856     if (context) EAX_reg(context) = 0;
 857 #endif
 858     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
 859     if (!(pModule = MODULE_GetPtr( pTask->hModule ))) return;
 860
 861 #ifndef WINELIB
 862     NE_InitializeDLLs( pTask->hModule );
 863
 864     if (context)
 865     {
 866         /* Registers on return are:
 867          * ax     1 if OK, 0 on error
 868          * cx     stack limit in bytes
 869          * dx     cmdShow parameter
 870          * si     instance handle of the previous instance
 871          * di     instance handle of the new task
 872          * es:bx  pointer to command-line inside PSP
 873          */
 874         EAX_reg(context) = 1;
 875         EBX_reg(context) = 0x81;
 876         ECX_reg(context) = pModule->stack_size;
 877         EDX_reg(context) = pTask->nCmdShow;
 878         ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 879         EDI_reg(context) = (DWORD)pTask->hInstance;
 880         ES_reg (context) = (WORD)pTask->hPDB;
 881     }
 882
 883     /* Initialize the local heap */
 884     if ( pModule->heap_size )
 885     {
 886         LocalInit( pTask->hInstance, 0, pModule->heap_size );
 887     }
 888 #endif
 889
 890     /* Initialize the INSTANCEDATA structure */
 891     pSegTable = NE_SEG_TABLE( pModule );
 892     stacklow = pSegTable[pModule->ss - 1].minsize;
 893     stackhi  = stacklow + pModule->stack_size;
 894     if (stackhi > 0xffff) stackhi = 0xffff;
 895     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 896     pinstance->stackbottom = stackhi; /* yup, that's right. Confused me too. */
 897     pinstance->stacktop    = stacklow;
 898 #ifndef WINELIB
 899     pinstance->stackmin    = IF1632_Saved16_sp;
 900 #endif
 901 }
 902
 903
 904 /***********************************************************************
 905  *           WaitEvent  (KERNEL.30)
 906  */
 907 BOOL16 WaitEvent( HTASK16 hTask )
 908 {
 909     TDB *pTask;
 910
 911     if (!hTask) hTask = hCurrentTask;
 912     pTask = (TDB *)GlobalLock16( hTask );
 913     if (pTask->nEvents > 0)
 914     {
 915         pTask->nEvents--;
 916         return FALSE;
 917     }
 918     TASK_YieldToSystem(pTask);
 919
 920     /* When we get back here, we have an event */
 921
 922     if (pTask->nEvents > 0) pTask->nEvents--;
 923     return TRUE;
 924 }
 925
 926
 927 /***********************************************************************
 928  *           PostEvent  (KERNEL.31)
 929  */
 930 void PostEvent( HTASK16 hTask )
 931 {
 932     TDB *pTask;
 933
 934     if (!hTask) hTask = hCurrentTask;
 935     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 936     pTask->nEvents++;
 937 }
 938
 939
 940 /***********************************************************************
 941  *           SetPriority  (KERNEL.32)
 942  */
 943 void SetPriority( HTASK16 hTask, INT16 delta )
 944 {
 945     TDB *pTask;
 946     INT16 newpriority;
 947
 948     if (!hTask) hTask = hCurrentTask;
 949     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 950     newpriority = pTask->priority + delta;
 951     if (newpriority < -32) newpriority = -32;
 952     else if (newpriority > 15) newpriority = 15;
 953
 954     pTask->priority = newpriority + 1;
 955     TASK_UnlinkTask( hTask );
 956     TASK_LinkTask( hTask );
 957     pTask->priority--;
 958 }
 959
 960
 961 /***********************************************************************
 962  *           LockCurrentTask  (KERNEL.33)
 963  */
 964 HTASK16 LockCurrentTask( BOOL16 bLock )
 965 {
 966     if (bLock) hLockedTask = hCurrentTask;
 967     else hLockedTask = 0;
 968     return hLockedTask;
 969 }
 970
 971
 972 /***********************************************************************
 973  *           IsTaskLocked  (KERNEL.122)
 974  */
 975 HTASK16 IsTaskLocked(void)
 976 {
 977     return hLockedTask;
 978 }
 979
 980
 981 /***********************************************************************
 982  *           OldYield  (KERNEL.117)
 983  */
 984 void OldYield(void)
 985 {
 986     TDB *pCurTask;
 987
 988     pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 989     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 990     TASK_YieldToSystem(pCurTask);
 991     if (pCurTask) pCurTask->nEvents--;
 992 }
 993
 994
 995 /***********************************************************************
 996  *           DirectedYield  (KERNEL.150)
 997  */
 998 void DirectedYield( HTASK16 hTask )
 999 {
1000     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
1001     pCurTask->hYieldTo = hTask;
1002     OldYield();
1003 }
1004
1005
1006 /***********************************************************************
1007  *           UserYield  (USER.332)
1008  */
1009 void UserYield(void)
1010 {
1011     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
1012     MESSAGEQUEUE *queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
1013     /* Handle sent messages */
1014     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
1015         QUEUE_ReceiveMessage( queue );
1016
1017     OldYield();
1018
1019     queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
1020     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
1021         QUEUE_ReceiveMessage( queue );
1022 }
1023
1024
1025 /***********************************************************************
1026  *           Yield  (KERNEL.29)
1027  */
1028 void Yield(void)
1029 {
1030     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
1031     if (pCurTask) pCurTask->hYieldTo = 0;
1032     if (pCurTask && pCurTask->hQueue) UserYield();
1033     else OldYield();
1034 }
1035
1036
1037 /***********************************************************************
1038  *           MakeProcInstance16  (KERNEL.51)
1039  */
1040 FARPROC16 MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
1041 {
1042 #ifdef WINELIB
1043     return func; /* func can be called directly in Winelib */
1044 #else
1045     BYTE *thunk;
1046     SEGPTR thunkaddr;
1047
1048     thunkaddr = TASK_AllocThunk( hCurrentTask );
1049     if (!thunkaddr) return (FARPROC16)0;
1050     thunk = PTR_SEG_TO_LIN( thunkaddr );
1051
1052     dprintf_task( stddeb, "MakeProcInstance(%08lx,%04x): got thunk %08lx\n",
1053                   (DWORD)func, hInstance, (DWORD)thunkaddr );
1054
1055     *thunk++ = 0xb8;    /* movw instance, %ax */
1056     *thunk++ = (BYTE)(hInstance & 0xff);
1057     *thunk++ = (BYTE)(hInstance >> 8);
1058     *thunk++ = 0xea;    /* ljmp func */
1059     *(DWORD *)thunk = (DWORD)func;
1060     return (FARPROC16)thunkaddr;
1061 #endif
1062 }
1063
1064
1065 /***********************************************************************
1066  *           FreeProcInstance16  (KERNEL.52)
1067  */
1068 void FreeProcInstance16( FARPROC16 func )
1069 {
1070 #ifndef WINELIB
1071     dprintf_task( stddeb, "FreeProcInstance(%08lx)\n", (DWORD)func );
1072     TASK_FreeThunk( hCurrentTask, (SEGPTR)func );
1073 #endif
1074 }
1075
1076
1077 /**********************************************************************
1078  *          GetCodeHandle    (KERNEL.93)
1079  */
1080 HANDLE16 GetCodeHandle( FARPROC16 proc )
1081 {
1082 #ifndef WINELIB32
1083     HANDLE16 handle;
1084     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
1085
1086     /* Return the code segment containing 'proc'. */
1087     /* Not sure if this is really correct (shouldn't matter that much). */
1088
1089     /* Check if it is really a thunk */
1090     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1091         handle = GlobalHandle16( thunk[6] + (thunk[7] << 8) );
1092     else
1093         handle = GlobalHandle16( HIWORD(proc) );
1094
1095     return handle;
1096 #else
1097     return (HANDLE16)proc;
1098 #endif
1099 }
1100
1101
1102 /***********************************************************************
1103  *           SetTaskQueue  (KERNEL.34)
1104  */
1105 HQUEUE16 SetTaskQueue( HTASK16 hTask, HQUEUE16 hQueue )
1106 {
1107     HQUEUE16 hPrev;
1108     TDB *pTask;
1109
1110     if (!hTask) hTask = hCurrentTask;
1111     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1112
1113     hPrev = pTask->hQueue;
1114     pTask->hQueue = hQueue;
1115
1116     TIMER_SwitchQueue( hPrev, hQueue );
1117
1118     return hPrev;
1119 }
1120
1121
1122 /***********************************************************************
1123  *           GetTaskQueue  (KERNEL.35)
1124  */
1125 HQUEUE16 GetTaskQueue( HTASK16 hTask )
1126 {
1127     TDB *pTask;
1128
1129     if (!hTask) hTask = hCurrentTask;
1130     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1131     return pTask->hQueue;
1132 }
1133
1134
1135 /***********************************************************************
1136  *           SwitchStackTo   (KERNEL.108)
1137  */
1138 void SwitchStackTo( WORD seg, WORD ptr, WORD top )
1139 {
1140     TDB *pTask;
1141     STACK16FRAME *oldFrame, *newFrame;
1142     INSTANCEDATA *pData;
1143     UINT16 copySize;
1144
1145     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
1146     if (!(pData = (INSTANCEDATA *)GlobalLock16( seg ))) return;
1147     dprintf_task( stddeb, "SwitchStackTo: old=%04x:%04x new=%04x:%04x\n",
1148                   IF1632_Saved16_ss, IF1632_Saved16_sp, seg, ptr );
1149
1150     /* Save the old stack */
1151
1152     oldFrame           = CURRENT_STACK16;
1153     pData->old_sp      = IF1632_Saved16_sp;
1154     pData->old_ss      = IF1632_Saved16_ss;
1155     pData->stacktop    = top;
1156     pData->stackmin    = ptr;
1157     pData->stackbottom = ptr;
1158
1159     /* Switch to the new stack */
1160
1161     IF1632_Saved16_ss = pTask->ss = seg;
1162     IF1632_Saved16_sp = pTask->sp = ptr - sizeof(STACK16FRAME);
1163     newFrame = CURRENT_STACK16;
1164
1165     /* Copy the stack frame and the local variables to the new stack */
1166
1167     copySize = oldFrame->bp - pData->old_sp;
1168     memcpy( newFrame, oldFrame, MAX( copySize, sizeof(STACK16FRAME) ));
1169 }
1170
1171
1172 /***********************************************************************
1173  *           SwitchStackBack   (KERNEL.109)
1174  *
1175  * Note: the function is declared as 'register' in the spec file in order
1176  * to make sure all registers are preserved, but we don't use them in any
1177  * way, so we don't need a SIGCONTEXT* argument.
1178  */
1179 void SwitchStackBack(void)
1180 {
1181     TDB *pTask;
1182     STACK16FRAME *oldFrame, *newFrame;
1183     INSTANCEDATA *pData;
1184
1185     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
1186     if (!(pData = (INSTANCEDATA *)GlobalLock16( IF1632_Saved16_ss ))) return;
1187     if (!pData->old_ss)
1188     {
1189         fprintf( stderr, "SwitchStackBack: no previous SwitchStackTo\n" );
1190         return;
1191     }
1192     dprintf_task( stddeb, "SwitchStackBack: restoring stack %04x:%04x\n",
1193                   pData->old_ss, pData->old_sp );
1194
1195     oldFrame = CURRENT_STACK16;
1196
1197     /* Switch back to the old stack */
1198
1199     IF1632_Saved16_ss = pTask->ss = pData->old_ss;
1200     IF1632_Saved16_sp = pTask->sp = pData->old_sp;
1201     pData->old_ss = pData->old_sp = 0;
1202
1203     /* Build a stack frame for the return */
1204
1205     newFrame = CURRENT_STACK16;
1206     newFrame->saved_ss = oldFrame->saved_ss;
1207     newFrame->saved_sp = oldFrame->saved_sp;
1208     newFrame->entry_ip = oldFrame->entry_ip;
1209     newFrame->entry_cs = oldFrame->entry_cs;
1210     newFrame->bp       = oldFrame->bp;
1211     newFrame->ip       = oldFrame->ip;
1212     newFrame->cs       = oldFrame->cs;
1213 }
1214
1215
1216 /***********************************************************************
1217  *           GetTaskQueueDS  (KERNEL.118)
1218  */
1219 #ifndef WINELIB
1220 void GetTaskQueueDS( SIGCONTEXT *context )
1221 {
1222     DS_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1223 }
1224 #endif  /* WINELIB */
1225
1226
1227 /***********************************************************************
1228  *           GetTaskQueueES  (KERNEL.119)
1229  */
1230 #ifndef WINELIB
1231 void GetTaskQueueES( SIGCONTEXT *context )
1232 {
1233     ES_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1234 }
1235 #endif  /* WINELIB */
1236
1237
1238 /***********************************************************************
1239  *           GetCurrentTask   (KERNEL.36)
1240  */
1241 HTASK16 GetCurrentTask(void)
1242 {
1243     return hCurrentTask;
1244 }
1245
1246 DWORD WIN16_GetCurrentTask(void)
1247 {
1248     /* This is the version used by relay code; the first task is */
1249     /* returned in the high word of the result */
1250     return MAKELONG( hCurrentTask, hFirstTask );
1251 }
1252
1253
1254 /***********************************************************************
1255  *           GetCurrentPDB   (KERNEL.37)
1256  */
1257 HANDLE16 GetCurrentPDB(void)
1258 {
1259     TDB *pTask;
1260
1261     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1262     return pTask->hPDB;
1263 }
1264
1265
1266 /***********************************************************************
1267  *           GetInstanceData   (KERNEL.54)
1268  */
1269 INT16 GetInstanceData( HINSTANCE16 instance, WORD buffer, INT16 len )
1270 {
1271     char *ptr = (char *)GlobalLock16( instance );
1272     if (!ptr || !len) return 0;
1273     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1274     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1275     return len;
1276 }
1277
1278
1279 /***********************************************************************
1280  *           GetExeVersion   (KERNEL.105)
1281  */
1282 WORD GetExeVersion(void)
1283 {
1284     TDB *pTask;
1285
1286     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1287     return pTask->version;
1288 }
1289
1290
1291 /***********************************************************************
1292  *           SetErrorMode   (KERNEL.107)
1293  */
1294 UINT SetErrorMode( UINT mode )
1295 {
1296     TDB *pTask;
1297     UINT oldMode;
1298
1299     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1300     oldMode = pTask->error_mode;
1301     pTask->error_mode = mode;
1302     return oldMode;
1303 }
1304
1305
1306 /***********************************************************************
1307  *           GetDOSEnvironment   (KERNEL.131)
1308  */
1309 SEGPTR GetDOSEnvironment(void)
1310 {
1311     TDB *pTask;
1312
1313     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1314     return (SEGPTR)WIN16_GlobalLock16( pTask->pdb.environment );
1315 }
1316
1317
1318 /***********************************************************************
1319  *           GetNumTasks   (KERNEL.152)
1320  */
1321 UINT16 GetNumTasks(void)
1322 {
1323     return nTaskCount;
1324 }
1325
1326
1327 /***********************************************************************
1328  *           GetTaskDS   (KERNEL.155)
1329  *
1330  * Note: this function apparently returns a DWORD with LOWORD == HIWORD.
1331  * I don't think we need to bother with this.
1332  */
1333 HINSTANCE16 GetTaskDS(void)
1334 {
1335     TDB *pTask;
1336
1337     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1338     return pTask->hInstance;
1339 }
1340
1341
1342 /***********************************************************************
1343  *           IsTask   (KERNEL.320)
1344  */
1345 BOOL16 IsTask( HTASK16 hTask )
1346 {
1347     TDB *pTask;
1348
1349     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1350     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1351     return (pTask->magic == TDB_MAGIC);
1352 }
1353
1354
1355 /***********************************************************************
1356  *           SetTaskSignalProc   (KERNEL.38)
1357  */
1358 FARPROC16 SetTaskSignalProc( HTASK16 hTask, FARPROC16 proc )
1359 {
1360     TDB *pTask;
1361     FARPROC16 oldProc;
1362
1363     if (!hTask) hTask = hCurrentTask;
1364     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return NULL;
1365     oldProc = pTask->userhandler;
1366     pTask->userhandler = proc;
1367     return oldProc;
1368 }
1369
1370
1371 /***********************************************************************
1372  *           SetSigHandler   (KERNEL.140)
1373  */
1374 WORD SetSigHandler( FARPROC16 newhandler, FARPROC16* oldhandler,
1375                     UINT16 *oldmode, UINT16 newmode, UINT16 flag )
1376 {
1377     fprintf(stdnimp,"SetSigHandler(%p,%p,%p,%d,%d), unimplemented.\n",
1378             newhandler,oldhandler,oldmode,newmode,flag );
1379
1380     if (flag != 1) return 0;
1381     if (!newmode) newhandler = NULL;  /* Default handler */
1382     if (newmode != 4)
1383     {
1384         TDB *pTask;
1385
1386         if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1387         if (oldmode) *oldmode = pTask->signal_flags;
1388         pTask->signal_flags = newmode;
1389         if (oldhandler) *oldhandler = pTask->sighandler;
1390         pTask->sighandler = newhandler;
1391     }
1392     return 0;
1393 }
1394
1395
1396 /***********************************************************************
1397  *           GlobalNotify   (KERNEL.154)
1398  */
1399 VOID GlobalNotify( FARPROC16 proc )
1400 {
1401     TDB *pTask;
1402
1403     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
1404     pTask->discardhandler = proc;
1405 }
1406
1407
1408 /***********************************************************************
1409  *           GetExePtr   (KERNEL.133)
1410  */
1411 HMODULE16 GetExePtr( HANDLE16 handle )
1412 {
1413     char *ptr;
1414     HTASK16 hTask;
1415     HANDLE16 owner;
1416
1417       /* Check for module handle */
1418
1419     if (!(ptr = GlobalLock16( handle ))) return 0;
1420     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return handle;
1421
1422       /* Check the owner for module handle */
1423
1424     owner = FarGetOwner( handle );
1425     if (!(ptr = GlobalLock16( owner ))) return 0;
1426     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return owner;
1427
1428       /* Search for this handle and its owner inside all tasks */
1429
1430     hTask = hFirstTask;
1431     while (hTask)
1432     {
1433         TDB *pTask = (TDB *)GlobalLock16( hTask );
1434         if ((hTask == handle) ||
1435             (pTask->hInstance == handle) ||
1436             (pTask->hQueue == handle) ||
1437             (pTask->hPDB == handle)) return pTask->hModule;
1438         if ((hTask == owner) ||
1439             (pTask->hInstance == owner) ||
1440             (pTask->hQueue == owner) ||
1441             (pTask->hPDB == owner)) return pTask->hModule;
1442         hTask = pTask->hNext;
1443     }
1444     return 0;
1445 }
1446
1447
1448 /***********************************************************************
1449  *           TaskFirst   (TOOLHELP.63)
1450  */
1451 BOOL16 TaskFirst( TASKENTRY *lpte )
1452 {
1453     lpte->hNext = hFirstTask;
1454     return TaskNext( lpte );
1455 }
1456
1457
1458 /***********************************************************************
1459  *           TaskNext   (TOOLHELP.64)
1460  */
1461 BOOL16 TaskNext( TASKENTRY *lpte )
1462 {
1463     TDB *pTask;
1464     INSTANCEDATA *pInstData;
1465
1466     dprintf_toolhelp( stddeb, "TaskNext(%p): task=%04x\n", lpte, lpte->hNext );
1467     if (!lpte->hNext) return FALSE;
1468     pTask = (TDB *)GlobalLock16( lpte->hNext );
1469     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1470     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1471     lpte->hTask         = lpte->hNext;
1472     lpte->hTaskParent   = pTask->hParent;
1473     lpte->hInst         = pTask->hInstance;
1474     lpte->hModule       = pTask->hModule;
1475     lpte->wSS           = pTask->ss;
1476     lpte->wSP           = pTask->sp;
1477     lpte->wStackTop     = pInstData->stacktop;
1478     lpte->wStackMinimum = pInstData->stackmin;
1479     lpte->wStackBottom  = pInstData->stackbottom;
1480     lpte->wcEvents      = pTask->nEvents;
1481     lpte->hQueue        = pTask->hQueue;
1482     strncpy( lpte->szModule, pTask->module_name, 8 );
1483     lpte->szModule[8]   = '\0';
1484     lpte->wPSPOffset    = 0x100;  /*??*/
1485     lpte->hNext         = pTask->hNext;
1486     return TRUE;
1487 }
1488
1489
1490 /***********************************************************************
1491  *           TaskFindHandle   (TOOLHELP.65)
1492  */
1493 BOOL16 TaskFindHandle( TASKENTRY *lpte, HTASK16 hTask )
1494 {
1495     lpte->hNext = hTask;
1496     return TaskNext( lpte );
1497 }
1498
1499
1500 /***********************************************************************
1501  *           GetAppCompatFlags   (KERNEL.354) (USER32.205)
1502  */
1503 DWORD GetAppCompatFlags( HTASK32 hTask )
1504 {
1505     TDB *pTask;
1506
1507     if (!hTask) hTask = GetCurrentTask();
1508     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1509     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1510     return pTask->compat_flags;
1511 }