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 "toolhelp.h"
  29 #include "stddebug.h"
  30 #include "debug.h"
  31 #include "dde_proc.h"
  32
  33   /* Min. number of thunks allocated when creating a new segment */
  34 #define MIN_THUNKS  32
  35
  36   /* 32-bit stack size for each task */
  37   /* Must not be greater than 64k, or MAKE_SEGPTR won't work */
  38 #define STACK32_SIZE 0x10000
  39
  40 extern void USER_AppExit(HTASK, HINSTANCE, HQUEUE );
  41 /* ------ Internal variables ------ */
  42
  43 static HTASK hFirstTask = 0;
  44 static HTASK hCurrentTask = 0;
  45 static HTASK hTaskToKill = 0;
  46 static HTASK hLockedTask = 0;
  47 static WORD nTaskCount = 0;
  48 static HANDLE hDOSEnvironment = 0;
  49
  50 /* ------ Internal declarations ------ */
  51
  52   /* TASK_Reschedule() 16-bit entry point */
  53 static FARPROC TASK_RescheduleProc;
  54
  55 #ifdef WINELIB
  56 #define TASK_SCHEDULE()  TASK_Reschedule();
  57 #else
  58 #define TASK_SCHEDULE()  CallTo16_word_(TASK_RescheduleProc,0)
  59 #endif
  60
  61 static HANDLE TASK_CreateDOSEnvironment(void);
  62
  63 /***********************************************************************
  64  *           TASK_Init
  65  */
  66 BOOL TASK_Init(void)
  67 {
  68     TASK_RescheduleProc = MODULE_GetWndProcEntry16( "TASK_Reschedule" );
  69     if (!(hDOSEnvironment = TASK_CreateDOSEnvironment()))
  70         fprintf( stderr, "Not enough memory for DOS Environment\n" );
  71     return (hDOSEnvironment != 0);
  72 }
  73
  74
  75 /***********************************************************************
  76  *           TASK_GetNextTask
  77  */
  78 HTASK TASK_GetNextTask( HTASK hTask )
  79 {
  80     TDB* pTask = (TDB*)GlobalLock16(hTask);
  81
  82     if (pTask->hNext) return pTask->hNext;
  83     return (hFirstTask != hTask) ? hFirstTask : 0;
  84 }
  85
  86
  87 /***********************************************************************
  88  *           TASK_CreateDOSEnvironment
  89  *
  90  * Create the original DOS environment.
  91  */
  92 static HANDLE TASK_CreateDOSEnvironment(void)
  93 {
  94     static const char program_name[] = "KRNL386.EXE";
  95     char **e, *p;
  96     int initial_size, size, i, winpathlen, sysdirlen;
  97     HANDLE handle;
  98
  99     extern char **environ;
 100
 101     /* DOS environment format:
 102      * ASCIIZ   string 1
 103      * ASCIIZ   string 2
 104      * ...
 105      * ASCIIZ   string n
 106      * ASCIIZ   PATH=xxx
 107      * BYTE     0
 108      * WORD     1
 109      * ASCIIZ   program name (e.g. C:\WINDOWS\SYSTEM\KRNL386.EXE)
 110      */
 111
 112     /* First compute the size of the fixed part of the environment */
 113
 114     for (i = winpathlen = 0; ; i++)
 115     {
 116         int len = DIR_GetDosPath( i, NULL, 0 );
 117         if (!len) break;
 118         winpathlen += len + 1;
 119     }
 120     if (!winpathlen) winpathlen = 1;
 121     sysdirlen  = GetSystemDirectory32A( NULL, 0 ) + 1;
 122     initial_size = 5 + winpathlen +           /* PATH=xxxx */
 123                    1 +                        /* BYTE 0 at end */
 124                    sizeof(WORD) +             /* WORD 1 */
 125                    sysdirlen +                /* program directory */
 126                    strlen(program_name) + 1;  /* program name */
 127
 128     /* Compute the total size of the Unix environment (except path) */
 129
 130     for (e = environ, size = initial_size; *e; e++)
 131     {
 132         if (lstrncmpi32A(*e, "path=", 5))
 133         {
 134             int len = strlen(*e) + 1;
 135             if (size + len >= 32767)
 136             {
 137                 fprintf( stderr, "Warning: environment larger than 32k.\n" );
 138                 break;
 139             }
 140             size += len;
 141         }
 142     }
 143
 144
 145     /* Now allocate the environment */
 146
 147     if (!(handle = GlobalAlloc16( GMEM_FIXED, size ))) return 0;
 148     p = (char *)GlobalLock16( handle );
 149
 150     /* And fill it with the Unix environment */
 151
 152     for (e = environ, size = initial_size; *e; e++)
 153     {
 154         if (lstrncmpi32A(*e, "path=", 5))
 155         {
 156             int len = strlen(*e) + 1;
 157             if (size + len >= 32767) break;
 158             strcpy( p, *e );
 159             size += len;
 160             p    += len;
 161         }
 162     }
 163
 164     /* Now add the path */
 165
 166     strcpy( p, "PATH=" );
 167     for (i = 0, p += 5; ; i++)
 168     {
 169         if (!DIR_GetDosPath( i, p, winpathlen )) break;
 170         p += strlen(p);
 171         *p++ = ';';
 172     }
 173     if (p[-1] == ';') p[-1] = '\0';
 174     else p++;
 175
 176     /* Now add the program name */
 177
 178     *p++ = '\0';
 179     PUT_WORD( p, 1 );
 180     p += sizeof(WORD);
 181     GetSystemDirectory32A( p, sysdirlen );
 182     strcat( p, "\\" );
 183     strcat( p, program_name );
 184
 185     /* Display it */
 186
 187     p = (char *) GlobalLock16( handle );
 188     dprintf_task(stddeb, "Master DOS environment at %p\n", p);
 189     for (; *p; p += strlen(p) + 1) dprintf_task(stddeb, "    %s\n", p);
 190     dprintf_task( stddeb, "Progname: %s\n", p+3 );
 191
 192     return handle;
 193 }
 194
 195
 196 /***********************************************************************
 197  *           TASK_LinkTask
 198  */
 199 static void TASK_LinkTask( HTASK hTask )
 200 {
 201     HTASK *prevTask;
 202     TDB *pTask;
 203
 204     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 205     prevTask = &hFirstTask;
 206     while (*prevTask)
 207     {
 208         TDB *prevTaskPtr = (TDB *)GlobalLock16( *prevTask );
 209         if (prevTaskPtr->priority >= pTask->priority) break;
 210         prevTask = &prevTaskPtr->hNext;
 211     }
 212     pTask->hNext = *prevTask;
 213     *prevTask = hTask;
 214     nTaskCount++;
 215 }
 216
 217
 218 /***********************************************************************
 219  *           TASK_UnlinkTask
 220  */
 221 static void TASK_UnlinkTask( HTASK hTask )
 222 {
 223     HTASK *prevTask;
 224     TDB *pTask;
 225
 226     prevTask = &hFirstTask;
 227     while (*prevTask && (*prevTask != hTask))
 228     {
 229         pTask = (TDB *)GlobalLock16( *prevTask );
 230         prevTask = &pTask->hNext;
 231     }
 232     if (*prevTask)
 233     {
 234         pTask = (TDB *)GlobalLock16( *prevTask );
 235         *prevTask = pTask->hNext;
 236         pTask->hNext = 0;
 237         nTaskCount--;
 238     }
 239 }
 240
 241
 242 /***********************************************************************
 243  *           TASK_CreateThunks
 244  *
 245  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 246  * and containing 'count' entries.
 247  */
 248 static void TASK_CreateThunks( HGLOBAL handle, WORD offset, WORD count )
 249 {
 250     int i;
 251     WORD free;
 252     THUNKS *pThunk;
 253
 254     pThunk = (THUNKS *)((BYTE *)GlobalLock16( handle ) + offset);
 255     pThunk->next = 0;
 256     pThunk->magic = THUNK_MAGIC;
 257     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 258     free = pThunk->free;
 259     for (i = 0; i < count-1; i++)
 260     {
 261         free += 8;  /* Offset of next thunk */
 262         pThunk->thunks[4*i] = free;
 263     }
 264     pThunk->thunks[4*i] = 0;  /* Last thunk */
 265 }
 266
 267
 268 /***********************************************************************
 269  *           TASK_AllocThunk
 270  *
 271  * Allocate a thunk for MakeProcInstance().
 272  */
 273 #ifndef WINELIB32
 274 static SEGPTR TASK_AllocThunk( HTASK hTask )
 275 {
 276     TDB *pTask;
 277     THUNKS *pThunk;
 278     WORD sel, base;
 279
 280     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 281     sel = pTask->hCSAlias;
 282     pThunk = &pTask->thunks;
 283     base = (int)pThunk - (int)pTask;
 284     while (!pThunk->free)
 285     {
 286         sel = pThunk->next;
 287         if (!sel)  /* Allocate a new segment */
 288         {
 289             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 290                                 pTask->hPDB, TRUE, FALSE, FALSE );
 291             if (!sel) return (SEGPTR)0;
 292             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 293             pThunk->next = sel;
 294         }
 295         pThunk = (THUNKS *)GlobalLock16( sel );
 296         base = 0;
 297     }
 298     base += pThunk->free;
 299     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 300     return PTR_SEG_OFF_TO_SEGPTR( sel, base );
 301 }
 302 #endif
 303
 304
 305 /***********************************************************************
 306  *           TASK_FreeThunk
 307  *
 308  * Free a MakeProcInstance() thunk.
 309  */
 310 #ifndef WINELIB32
 311 static BOOL TASK_FreeThunk( HTASK hTask, SEGPTR thunk )
 312 {
 313     TDB *pTask;
 314     THUNKS *pThunk;
 315     WORD sel, base;
 316
 317     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
 318     sel = pTask->hCSAlias;
 319     pThunk = &pTask->thunks;
 320     base = (int)pThunk - (int)pTask;
 321     while (sel && (sel != HIWORD(thunk)))
 322     {
 323         sel = pThunk->next;
 324         pThunk = (THUNKS *)GlobalLock16( sel );
 325         base = 0;
 326     }
 327     if (!sel) return FALSE;
 328     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 329     pThunk->free = LOWORD(thunk) - base;
 330     return TRUE;
 331 }
 332 #endif
 333
 334
 335 /***********************************************************************
 336  *           TASK_CallToStart
 337  *
 338  * 32-bit entry point for a new task. This function is responsible for
 339  * setting up the registers and jumping to the 16-bit entry point.
 340  */
 341 #ifndef WINELIB
 342 static void TASK_CallToStart(void)
 343 {
 344     int cs_reg, ds_reg, ip_reg;
 345     TDB *pTask = (TDB *)GlobalLock16( hCurrentTask );
 346     NE_MODULE *pModule = MODULE_GetPtr( pTask->hModule );
 347     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 348
 349     /* Registers at initialization must be:
 350      * ax   zero
 351      * bx   stack size in bytes
 352      * cx   heap size in bytes
 353      * si   previous app instance
 354      * di   current app instance
 355      * bp   zero
 356      * es   selector to the PSP
 357      * ds   dgroup of the application
 358      * ss   stack selector
 359      * sp   top of the stack
 360      */
 361
 362     cs_reg = pSegTable[pModule->cs - 1].selector;
 363     ip_reg = pModule->ip;
 364     ds_reg = pSegTable[pModule->dgroup - 1].selector;
 365
 366     IF1632_Saved16_ss = pTask->ss;
 367     IF1632_Saved16_sp = pTask->sp;
 368     dprintf_task( stddeb, "Starting main program: cs:ip=%04x:%04x ds=%04x ss:sp=%04x:%04x\n",
 369                  cs_reg, ip_reg, ds_reg,
 370                  IF1632_Saved16_ss, IF1632_Saved16_sp);
 371
 372     CallTo16_regs_( (FARPROC)(cs_reg << 16 | ip_reg), ds_reg,
 373                    pTask->hPDB /*es*/, 0 /*bp*/, 0 /*ax*/,
 374                    pModule->stack_size /*bx*/, pModule->heap_size /*cx*/,
 375                    0 /*dx*/, 0 /*si*/, ds_reg /*di*/ );
 376
 377     /* This should never return */
 378     fprintf( stderr, "TASK_CallToStart: Main program returned!\n" );
 379     TASK_KillCurrentTask( 1 );
 380 }
 381 #endif
 382
 383
 384 /***********************************************************************
 385  *           TASK_CreateTask
 386  */
 387 HTASK TASK_CreateTask( HMODULE hModule, HANDLE hInstance, HANDLE hPrevInstance,
 388                        HANDLE hEnvironment, char *cmdLine, WORD cmdShow )
 389 {
 390     HTASK hTask;
 391     TDB *pTask;
 392     HANDLE hParentEnv;
 393     NE_MODULE *pModule;
 394     SEGTABLEENTRY *pSegTable;
 395     LPSTR name;
 396     char filename[256];
 397 #ifndef WINELIB32
 398     char *stack16Top, *stack32Top;
 399     STACK16FRAME *frame16;
 400     STACK32FRAME *frame32;
 401     extern DWORD CALLTO16_RetAddr_word;
 402 #endif
 403
 404     if (!(pModule = MODULE_GetPtr( hModule ))) return 0;
 405     pSegTable = NE_SEG_TABLE( pModule );
 406
 407       /* Allocate the task structure */
 408
 409     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 410                           hModule, FALSE, FALSE, FALSE );
 411     if (!hTask) return 0;
 412     pTask = (TDB *)GlobalLock16( hTask );
 413
 414       /* Allocate the new environment block */
 415
 416     if (!(hParentEnv = hEnvironment))
 417     {
 418         TDB *pParent = (TDB *)GlobalLock16( hCurrentTask );
 419         hParentEnv = pParent ? pParent->pdb.environment : hDOSEnvironment;
 420     }
 421     /* FIXME: do we really need to make a copy also when */
 422     /*        we don't use the parent environment? */
 423     if (!(hEnvironment = GlobalAlloc16( GMEM_FIXED, GlobalSize16(hParentEnv))))
 424     {
 425         GlobalFree16( hTask );
 426         return 0;
 427     }
 428     memcpy( GlobalLock16( hEnvironment ), GlobalLock16( hParentEnv ),
 429             GlobalSize16( hParentEnv ) );
 430
 431       /* Get current directory */
 432
 433     GetModuleFileName( hModule, filename, sizeof(filename) );
 434     name = strrchr(filename, '\\');
 435     if (name) *(name+1) = 0;
 436
 437       /* Fill the task structure */
 438
 439     pTask->nEvents       = 1;  /* So the task can be started */
 440     pTask->hSelf         = hTask;
 441     pTask->flags         = 0;
 442     pTask->version       = pModule->expected_version;
 443     pTask->hInstance     = hInstance;
 444     pTask->hPrevInstance = hPrevInstance;
 445     pTask->hModule       = hModule;
 446     pTask->hParent       = hCurrentTask;
 447     pTask->curdrive      = filename[0] - 'A' + 0x80;
 448     strcpy( pTask->curdir, filename+2 );
 449     pTask->magic         = TDB_MAGIC;
 450     pTask->nCmdShow      = cmdShow;
 451
 452       /* Create the thunks block */
 453
 454     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 455
 456       /* Copy the module name */
 457
 458     name = MODULE_GetModuleName( hModule );
 459     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 460
 461       /* Allocate a selector for the PDB */
 462
 463     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB),
 464                                       hModule, FALSE, FALSE, FALSE, NULL );
 465
 466       /* Fill the PDB */
 467
 468     pTask->pdb.int20 = 0x20cd;
 469 #ifndef WINELIB
 470     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 471     *(FARPROC16 *)&pTask->pdb.dispatcher[1] = MODULE_GetEntryPoint( GetModuleHandle("KERNEL"), 102 );  /* KERNEL.102 is DOS3Call() */
 472     pTask->pdb.savedint22 = INT_GetHandler( 0x22 );
 473     pTask->pdb.savedint23 = INT_GetHandler( 0x23 );
 474     pTask->pdb.savedint24 = INT_GetHandler( 0x24 );
 475     pTask->pdb.fileHandlesPtr = (SEGPTR)MAKELONG( 0x18,
 476                                               GlobalHandleToSel(pTask->hPDB) );
 477 #else
 478     pTask->pdb.fileHandlesPtr = pTask->pdb.fileHandles;
 479 #endif
 480     memset( pTask->pdb.fileHandles, 0xff, sizeof(pTask->pdb.fileHandles) );
 481     pTask->pdb.environment    = hEnvironment;
 482     pTask->pdb.nbFiles        = 20;
 483     lstrcpyn32A( pTask->pdb.cmdLine + 1, cmdLine, 127 );
 484     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 485
 486       /* Get the compatibility flags */
 487
 488     pTask->compat_flags = GetProfileInt( name, "Compatibility", 0 );
 489
 490       /* Allocate a code segment alias for the TDB */
 491
 492     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 493                                           sizeof(TDB), pTask->hPDB, TRUE,
 494                                           FALSE, FALSE, NULL );
 495
 496       /* Set the owner of the environment block */
 497
 498     FarSetOwner( pTask->pdb.environment, pTask->hPDB );
 499
 500       /* Default DTA overwrites command-line */
 501
 502     pTask->dta = PTR_SEG_OFF_TO_SEGPTR( pTask->hPDB,
 503                                 (int)&pTask->pdb.cmdLine - (int)&pTask->pdb );
 504
 505       /* Allocate the 32-bit stack */
 506
 507 #ifndef WINELIB
 508     pTask->hStack32 = GLOBAL_Alloc( GMEM_FIXED, STACK32_SIZE, pTask->hPDB,
 509                                     FALSE, FALSE, FALSE );
 510
 511       /* Create the 32-bit stack frame */
 512
 513     *(DWORD *)GlobalLock16(pTask->hStack32) = 0xDEADBEEF;
 514     stack32Top = (char*)GlobalLock16(pTask->hStack32) + STACK32_SIZE;
 515     frame32 = (STACK32FRAME *)stack32Top - 1;
 516     frame32->saved_esp = (DWORD)stack32Top;
 517     frame32->edi = 0;
 518     frame32->esi = 0;
 519     frame32->edx = 0;
 520     frame32->ecx = 0;
 521     frame32->ebx = 0;
 522     frame32->ebp = 0;
 523     frame32->retaddr = (DWORD)TASK_CallToStart;
 524     frame32->codeselector = WINE_CODE_SELECTOR;
 525     pTask->esp = (DWORD)frame32;
 526
 527       /* Create the 16-bit stack frame */
 528
 529     pTask->ss = hInstance;
 530     pTask->sp = ((pModule->sp != 0) ? pModule->sp :
 531                  pSegTable[pModule->ss-1].minsize + pModule->stack_size) & ~1;
 532     stack16Top = (char *)PTR_SEG_OFF_TO_LIN( pTask->ss, pTask->sp );
 533     frame16 = (STACK16FRAME *)stack16Top - 1;
 534     frame16->saved_ss = 0; /*pTask->ss;*/
 535     frame16->saved_sp = 0; /*pTask->sp;*/
 536     frame16->ds = frame16->es = pTask->hInstance;
 537     frame16->entry_point = 0;
 538     frame16->entry_ip = OFFSETOF(TASK_RescheduleProc) + 14;
 539     frame16->entry_cs = SELECTOROF(TASK_RescheduleProc);
 540     frame16->bp = 0;
 541     frame16->ip = LOWORD( CALLTO16_RetAddr_word );
 542     frame16->cs = HIWORD( CALLTO16_RetAddr_word );
 543     pTask->sp -= sizeof(STACK16FRAME);
 544
 545       /* If there's no 16-bit stack yet, use a part of the new task stack */
 546       /* This is only needed to have a stack to switch from on the first  */
 547       /* call to DirectedYield(). */
 548
 549     if (!IF1632_Saved16_ss)
 550     {
 551         IF1632_Saved16_ss = pTask->ss;
 552         IF1632_Saved16_sp = pTask->sp;
 553     }
 554
 555       /* Add a breakpoint at the start of the task */
 556
 557     if (Options.debug)
 558     {
 559         if (pModule->flags & NE_FFLAGS_WIN32)
 560         {
 561             DBG_ADDR addr = { 0, pModule->pe_module->load_addr +
 562                               pModule->pe_module->pe_header->opt_coff.AddressOfEntryPoint };
 563             fprintf( stderr, "Win32 task '%s': ", name );
 564             DEBUG_AddBreakpoint( &addr );
 565         }
 566         else
 567         {
 568             DBG_ADDR addr = { pSegTable[pModule->cs-1].selector, pModule->ip };
 569             fprintf( stderr, "Win16 task '%s': ", name );
 570             DEBUG_AddBreakpoint( &addr );
 571         }
 572     }
 573 #endif
 574
 575       /* Add the task to the linked list */
 576
 577     TASK_LinkTask( hTask );
 578
 579     dprintf_task( stddeb, "CreateTask: module='%s' cmdline='%s' task=%04x\n",
 580                   name, cmdLine, hTask );
 581
 582     return hTask;
 583 }
 584
 585
 586 /***********************************************************************
 587  *           TASK_DeleteTask
 588  */
 589 static void TASK_DeleteTask( HTASK hTask )
 590 {
 591     TDB *pTask;
 592     HANDLE hPDB;
 593
 594     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 595     hPDB = pTask->hPDB;
 596
 597     /* Free the task module */
 598
 599     FreeModule16( pTask->hModule );
 600
 601     /* Close all open files of this task */
 602
 603     FILE_CloseAllFiles( pTask->hPDB );
 604
 605     /* Free the selector aliases */
 606
 607     GLOBAL_FreeBlock( pTask->hCSAlias );
 608     GLOBAL_FreeBlock( pTask->hPDB );
 609
 610     /* Free the task structure itself */
 611
 612     GlobalFree16( hTask );
 613
 614     /* Free all memory used by this task (including the 32-bit stack, */
 615     /* the environment block and the thunk segments). */
 616
 617     GlobalFreeAll( hPDB );
 618 }
 619
 620
 621 /***********************************************************************
 622  *           TASK_KillCurrentTask
 623  *
 624  * Kill the currently running task. As it's not possible to kill the
 625  * current task like this, it is simply marked for destruction, and will
 626  * be killed when either TASK_Reschedule or this function is called again
 627  * in the context of another task.
 628  */
 629 void TASK_KillCurrentTask( int exitCode )
 630 {
 631     extern void EXEC_ExitWindows( int retCode );
 632
 633     TDB* pTask = (TDB*) GlobalLock16( hCurrentTask );
 634     if (!pTask) EXEC_ExitWindows(0);  /* No current task yet */
 635
 636     /* Perform USER cleanup */
 637
 638     USER_AppExit( hCurrentTask, pTask->hInstance, pTask->hQueue );
 639
 640     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 641     {
 642         /* If another task is already marked for destruction, */
 643         /* we can kill it now, as we are in another context.  */
 644         TASK_DeleteTask( hTaskToKill );
 645     }
 646
 647     if (nTaskCount <= 1)
 648     {
 649         dprintf_task( stddeb, "Killing the last task, exiting\n" );
 650         EXEC_ExitWindows( 0 );
 651     }
 652
 653     /* Remove the task from the list to be sure we never switch back to it */
 654     TASK_UnlinkTask( hCurrentTask );
 655
 656     hTaskToKill = hCurrentTask;
 657     hLockedTask = 0;
 658
 659     Yield();
 660     /* We should never return from this Yield() */
 661
 662     fprintf(stderr,"It's alive! Alive!!!\n");
 663     exit(1);
 664 }
 665
 666
 667 /***********************************************************************
 668  *           TASK_Reschedule
 669  *
 670  * This is where all the magic of task-switching happens!
 671  *
 672  * This function should only be called via the TASK_SCHEDULE() macro, to make
 673  * sure that all the context is saved correctly.
 674  */
 675 void TASK_Reschedule(void)
 676 {
 677     TDB *pOldTask = NULL, *pNewTask;
 678     HTASK hTask = 0;
 679
 680 #ifdef CONFIG_IPC
 681     dde_reschedule();
 682 #endif
 683       /* First check if there's a task to kill */
 684
 685     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 686     {
 687         TASK_DeleteTask( hTaskToKill );
 688         hTaskToKill = 0;
 689     }
 690
 691     /* Flush any X events that happened in the meantime */
 692
 693     EVENT_WaitXEvent( FALSE );
 694
 695     /* Find a task to yield to */
 696
 697     pOldTask = (TDB *)GlobalLock16( hCurrentTask );
 698     if (pOldTask && pOldTask->hYieldTo)
 699     {
 700         /* If a task is stored in hYieldTo of the current task (put there */
 701         /* by DirectedYield), yield to it only if it has events pending.  */
 702         hTask = pOldTask->hYieldTo;
 703         if (!(pNewTask = (TDB *)GlobalLock16( hTask )) || !pNewTask->nEvents)
 704             hTask = 0;
 705     }
 706
 707     while (!hTask)
 708     {
 709         /* Find a task that has an event pending */
 710
 711         hTask = hFirstTask;
 712         while (hTask)
 713         {
 714             pNewTask = (TDB *)GlobalLock16( hTask );
 715             if (pNewTask->nEvents) break;
 716             hTask = pNewTask->hNext;
 717         }
 718         if (hLockedTask && (hTask != hLockedTask)) hTask = 0;
 719         if (hTask) break;
 720
 721         /* No task found, wait for some events to come in */
 722
 723         EVENT_WaitXEvent( TRUE );
 724     }
 725
 726     if (hTask == hCurrentTask) return;  /* Nothing to do */
 727
 728     pNewTask = (TDB *)GlobalLock16( hTask );
 729     dprintf_task( stddeb, "Switching to task %04x (%.8s)\n",
 730                   hTask, pNewTask->module_name );
 731
 732       /* Save the stacks of the previous task (if any) */
 733
 734 #ifndef WINELIB /* FIXME: JBP: IF1632 not allowed in libwine.a */
 735     if (pOldTask)
 736     {
 737         pOldTask->ss  = IF1632_Saved16_ss;
 738         pOldTask->sp  = IF1632_Saved16_sp;
 739         pOldTask->esp = IF1632_Saved32_esp;
 740     }
 741     else IF1632_Original32_esp = IF1632_Saved32_esp;
 742 #endif
 743
 744      /* Make the task the last in the linked list (round-robin scheduling) */
 745
 746     pNewTask->priority++;
 747     TASK_UnlinkTask( hTask );
 748     TASK_LinkTask( hTask );
 749     pNewTask->priority--;
 750
 751       /* Switch to the new stack */
 752
 753     hCurrentTask = hTask;
 754 #ifndef WINELIB /* FIXME: JBP: IF1632 not allowed in libwine.a */
 755     IF1632_Saved16_ss   = pNewTask->ss;
 756     IF1632_Saved16_sp   = pNewTask->sp;
 757     IF1632_Saved32_esp  = pNewTask->esp;
 758     IF1632_Stack32_base = WIN16_GlobalLock16( pNewTask->hStack32 );
 759 #endif
 760 }
 761
 762
 763 /***********************************************************************
 764  *           InitTask  (KERNEL.91)
 765  */
 766 #ifdef WINELIB
 767 void InitTask(void)
 768 #else
 769 void InitTask( SIGCONTEXT *context )
 770 #endif
 771 {
 772     TDB *pTask;
 773     NE_MODULE *pModule;
 774     SEGTABLEENTRY *pSegTable;
 775     INSTANCEDATA *pinstance;
 776     LONG stacklow, stackhi;
 777
 778 #ifndef WINELIB
 779     EAX_reg(context) = 0;
 780 #endif
 781     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
 782     if (!(pModule = MODULE_GetPtr( pTask->hModule ))) return;
 783
 784 #ifndef WINELIB
 785     NE_InitializeDLLs( pTask->hModule );
 786
 787     /* Registers on return are:
 788      * ax     1 if OK, 0 on error
 789      * cx     stack limit in bytes
 790      * dx     cmdShow parameter
 791      * si     instance handle of the previous instance
 792      * di     instance handle of the new task
 793      * es:bx  pointer to command-line inside PSP
 794      */
 795     EAX_reg(context) = 1;
 796     EBX_reg(context) = 0x81;
 797     ECX_reg(context) = pModule->stack_size;
 798     EDX_reg(context) = pTask->nCmdShow;
 799     ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 800     EDI_reg(context) = (DWORD)pTask->hInstance;
 801     ES_reg (context) = (WORD)pTask->hPDB;
 802
 803     /* Initialize the local heap */
 804     if ( pModule->heap_size )
 805     {
 806         LocalInit( pTask->hInstance, 0, pModule->heap_size );
 807     }
 808 #endif
 809
 810     /* Initialize the INSTANCEDATA structure */
 811     pSegTable = NE_SEG_TABLE( pModule );
 812     stacklow = pSegTable[pModule->ss - 1].minsize;
 813     stackhi  = stacklow + pModule->stack_size;
 814     if (stackhi > 0xffff) stackhi = 0xffff;
 815     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 816     pinstance->stackbottom = stackhi; /* yup, that's right. Confused me too. */
 817     pinstance->stacktop    = stacklow;
 818 #ifndef WINELIB
 819     pinstance->stackmin    = IF1632_Saved16_sp;
 820 #endif
 821 }
 822
 823
 824 /***********************************************************************
 825  *           WaitEvent  (KERNEL.30)
 826  */
 827 BOOL WaitEvent( HTASK hTask )
 828 {
 829     TDB *pTask;
 830
 831     if (!hTask) hTask = hCurrentTask;
 832     pTask = (TDB *)GlobalLock16( hTask );
 833     if (pTask->nEvents > 0)
 834     {
 835         pTask->nEvents--;
 836         return FALSE;
 837     }
 838     TASK_SCHEDULE();
 839     /* When we get back here, we have an event */
 840     if (pTask->nEvents > 0) pTask->nEvents--;
 841     else fprintf( stderr, "WaitEvent: reschedule returned without event\n" );
 842     return TRUE;
 843 }
 844
 845
 846 /***********************************************************************
 847  *           PostEvent  (KERNEL.31)
 848  */
 849 void PostEvent( HTASK hTask )
 850 {
 851     TDB *pTask;
 852
 853     if (!hTask) hTask = hCurrentTask;
 854     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 855     pTask->nEvents++;
 856 }
 857
 858
 859 /***********************************************************************
 860  *           SetPriority  (KERNEL.32)
 861  */
 862 void SetPriority( HTASK hTask, int delta )
 863 {
 864     TDB *pTask;
 865     int newpriority;
 866
 867     if (!hTask) hTask = hCurrentTask;
 868     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 869     newpriority = pTask->priority + delta;
 870     if (newpriority < -32) newpriority = -32;
 871     else if (newpriority > 15) newpriority = 15;
 872
 873     pTask->priority = newpriority + 1;
 874     TASK_UnlinkTask( hTask );
 875     TASK_LinkTask( hTask );
 876     pTask->priority--;
 877 }
 878
 879
 880 /***********************************************************************
 881  *           LockCurrentTask  (KERNEL.33)
 882  */
 883 HTASK LockCurrentTask( BOOL bLock )
 884 {
 885     if (bLock) hLockedTask = hCurrentTask;
 886     else hLockedTask = 0;
 887     return hLockedTask;
 888 }
 889
 890
 891 /***********************************************************************
 892  *           IsTaskLocked  (KERNEL.122)
 893  */
 894 HTASK IsTaskLocked(void)
 895 {
 896     return hLockedTask;
 897 }
 898
 899
 900 /***********************************************************************
 901  *           OldYield  (KERNEL.117)
 902  */
 903 void OldYield(void)
 904 {
 905     TDB *pCurTask;
 906
 907     pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 908     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 909     TASK_SCHEDULE();
 910     if (pCurTask) pCurTask->nEvents--;
 911 }
 912
 913
 914 /***********************************************************************
 915  *           DirectedYield  (KERNEL.150)
 916  */
 917 void DirectedYield( HTASK hTask )
 918 {
 919     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 920     pCurTask->hYieldTo = hTask;
 921     OldYield();
 922 }
 923
 924
 925 /***********************************************************************
 926  *           UserYield  (USER.332)
 927  */
 928 void UserYield(void)
 929 {
 930     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 931     MESSAGEQUEUE *queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 932     /* Handle sent messages */
 933     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
 934         QUEUE_ReceiveMessage( queue );
 935
 936     OldYield();
 937
 938     queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 939     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
 940         QUEUE_ReceiveMessage( queue );
 941 }
 942
 943
 944 /***********************************************************************
 945  *           Yield  (KERNEL.29)
 946  */
 947 void Yield(void)
 948 {
 949     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 950     if (pCurTask) pCurTask->hYieldTo = 0;
 951     if (pCurTask && pCurTask->hQueue) UserYield();
 952     else OldYield();
 953 }
 954
 955
 956 /***********************************************************************
 957  *           MakeProcInstance16  (KERNEL.51)
 958  */
 959 FARPROC16 MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 960 {
 961 #ifdef WINELIB
 962     return func; /* func can be called directly in Winelib */
 963 #else
 964     BYTE *thunk;
 965     SEGPTR thunkaddr;
 966
 967     thunkaddr = TASK_AllocThunk( hCurrentTask );
 968     if (!thunkaddr) return (FARPROC)0;
 969     thunk = PTR_SEG_TO_LIN( thunkaddr );
 970
 971     dprintf_task( stddeb, "MakeProcInstance(%08lx,%04x): got thunk %08lx\n",
 972                   (DWORD)func, hInstance, (DWORD)thunkaddr );
 973
 974     *thunk++ = 0xb8;    /* movw instance, %ax */
 975     *thunk++ = (BYTE)(hInstance & 0xff);
 976     *thunk++ = (BYTE)(hInstance >> 8);
 977     *thunk++ = 0xea;    /* ljmp func */
 978     *(DWORD *)thunk = (DWORD)func;
 979     return (FARPROC)thunkaddr;
 980 #endif
 981 }
 982
 983
 984 /***********************************************************************
 985  *           FreeProcInstance16  (KERNEL.52)
 986  */
 987 void FreeProcInstance16( FARPROC16 func )
 988 {
 989 #ifndef WINELIB
 990     dprintf_task( stddeb, "FreeProcInstance(%08lx)\n", (DWORD)func );
 991     TASK_FreeThunk( hCurrentTask, (SEGPTR)func );
 992 #endif
 993 }
 994
 995
 996 /**********************************************************************
 997  *          GetCodeHandle    (KERNEL.93)
 998  */
 999 HANDLE GetCodeHandle( FARPROC proc )
1000 {
1001 #ifndef WINELIB32
1002     HANDLE handle;
1003     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
1004
1005     /* Return the code segment containing 'proc'. */
1006     /* Not sure if this is really correct (shouldn't matter that much). */
1007
1008     /* Check if it is really a thunk */
1009     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1010         handle = GlobalHandle16( thunk[6] + (thunk[7] << 8) );
1011     else
1012         handle = GlobalHandle16( HIWORD(proc) );
1013
1014     return handle;
1015 #else
1016     return (HANDLE)proc;
1017 #endif
1018 }
1019
1020
1021 /***********************************************************************
1022  *           SetTaskQueue  (KERNEL.34)
1023  */
1024 HQUEUE SetTaskQueue( HANDLE hTask, HQUEUE hQueue )
1025 {
1026     HQUEUE hPrev;
1027     TDB *pTask;
1028
1029     if (!hTask) hTask = hCurrentTask;
1030     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1031
1032     hPrev = pTask->hQueue;
1033     pTask->hQueue = hQueue;
1034
1035     TIMER_SwitchQueue( hPrev, hQueue );
1036
1037     return hPrev;
1038 }
1039
1040
1041 /***********************************************************************
1042  *           GetTaskQueue  (KERNEL.35)
1043  */
1044 HQUEUE16 GetTaskQueue( HTASK16 hTask )
1045 {
1046     TDB *pTask;
1047
1048     if (!hTask) hTask = hCurrentTask;
1049     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1050     return pTask->hQueue;
1051 }
1052
1053
1054 /***********************************************************************
1055  *           GetTaskQueueDS  (KERNEL.118)
1056  */
1057 #ifndef WINELIB
1058 void GetTaskQueueDS( SIGCONTEXT *context )
1059 {
1060     DS_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1061 }
1062 #endif  /* WINELIB */
1063
1064
1065 /***********************************************************************
1066  *           GetTaskQueueES  (KERNEL.119)
1067  */
1068 #ifndef WINELIB
1069 void GetTaskQueueES( SIGCONTEXT *context )
1070 {
1071     ES_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1072 }
1073 #endif  /* WINELIB */
1074
1075
1076 /***********************************************************************
1077  *           GetCurrentTask   (KERNEL.36)
1078  */
1079 HTASK16 GetCurrentTask(void)
1080 {
1081     return hCurrentTask;
1082 }
1083
1084 DWORD WIN16_GetCurrentTask(void)
1085 {
1086     /* This is the version used by relay code; the first task is */
1087     /* returned in the high word of the result */
1088     return MAKELONG( hCurrentTask, hFirstTask );
1089 }
1090
1091
1092 /***********************************************************************
1093  *           GetCurrentPDB   (KERNEL.37)
1094  */
1095 HANDLE GetCurrentPDB(void)
1096 {
1097     TDB *pTask;
1098
1099     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1100     return pTask->hPDB;
1101 }
1102
1103
1104 /***********************************************************************
1105  *           GetInstanceData   (KERNEL.54)
1106  */
1107 int GetInstanceData( HANDLE instance, WORD buffer, int len )
1108 {
1109     char *ptr = (char *)GlobalLock16( instance );
1110     if (!ptr || !len) return 0;
1111     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1112     memcpy( ptr + buffer, (char *)GlobalLock16( CURRENT_DS ) + buffer, len );
1113     return len;
1114 }
1115
1116
1117 /***********************************************************************
1118  *           SetErrorMode   (KERNEL.107)
1119  */
1120 UINT SetErrorMode( UINT mode )
1121 {
1122     TDB *pTask;
1123     UINT oldMode;
1124
1125     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1126     oldMode = pTask->error_mode;
1127     pTask->error_mode = mode;
1128     return oldMode;
1129 }
1130
1131
1132 /***********************************************************************
1133  *           GetDOSEnvironment   (KERNEL.131)
1134  */
1135 SEGPTR GetDOSEnvironment(void)
1136 {
1137     TDB *pTask;
1138
1139     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1140     return (SEGPTR)WIN16_GlobalLock16( pTask->pdb.environment );
1141 }
1142
1143
1144 /***********************************************************************
1145  *           GetNumTasks   (KERNEL.152)
1146  */
1147 WORD GetNumTasks(void)
1148 {
1149     return nTaskCount;
1150 }
1151
1152
1153 /***********************************************************************
1154  *           GetTaskDS   (KERNEL.155)
1155  */
1156 HINSTANCE16 GetTaskDS(void)
1157 {
1158     TDB *pTask;
1159
1160     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1161     return pTask->hInstance;
1162 }
1163
1164
1165 /***********************************************************************
1166  *           IsTask   (KERNEL.320)
1167  */
1168 BOOL IsTask( HTASK hTask )
1169 {
1170     TDB *pTask;
1171
1172     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1173     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1174     return (pTask->magic == TDB_MAGIC);
1175 }
1176
1177
1178 /***********************************************************************
1179  *           GetExePtr   (KERNEL.133)
1180  */
1181 HMODULE GetExePtr( HANDLE handle )
1182 {
1183     char *ptr;
1184     HTASK hTask;
1185     HANDLE owner;
1186
1187       /* Check for module handle */
1188
1189     if (!(ptr = GlobalLock16( handle ))) return 0;
1190     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return handle;
1191
1192       /* Check the owner for module handle */
1193
1194     owner = FarGetOwner( handle );
1195     if (!(ptr = GlobalLock16( owner ))) return 0;
1196     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return owner;
1197
1198       /* Search for this handle and its owner inside all tasks */
1199
1200     hTask = hFirstTask;
1201     while (hTask)
1202     {
1203         TDB *pTask = (TDB *)GlobalLock16( hTask );
1204         if ((hTask == handle) ||
1205             (pTask->hInstance == handle) ||
1206             (pTask->hQueue == handle) ||
1207             (pTask->hPDB == handle)) return pTask->hModule;
1208         if ((hTask == owner) ||
1209             (pTask->hInstance == owner) ||
1210             (pTask->hQueue == owner) ||
1211             (pTask->hPDB == owner)) return pTask->hModule;
1212         hTask = pTask->hNext;
1213     }
1214     return 0;
1215 }
1216
1217
1218 /***********************************************************************
1219  *           TaskFirst   (TOOLHELP.63)
1220  */
1221 BOOL16 TaskFirst( TASKENTRY *lpte )
1222 {
1223     lpte->hNext = hFirstTask;
1224     return TaskNext( lpte );
1225 }
1226
1227
1228 /***********************************************************************
1229  *           TaskNext   (TOOLHELP.64)
1230  */
1231 BOOL16 TaskNext( TASKENTRY *lpte )
1232 {
1233     TDB *pTask;
1234     INSTANCEDATA *pInstData;
1235
1236     dprintf_toolhelp( stddeb, "TaskNext(%p): task=%04x\n", lpte, lpte->hNext );
1237     if (!lpte->hNext) return FALSE;
1238     pTask = (TDB *)GlobalLock16( lpte->hNext );
1239     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1240     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1241     lpte->hTask         = lpte->hNext;
1242     lpte->hTaskParent   = pTask->hParent;
1243     lpte->hInst         = pTask->hInstance;
1244     lpte->hModule       = pTask->hModule;
1245     lpte->wSS           = pTask->ss;
1246     lpte->wSP           = pTask->sp;
1247     lpte->wStackTop     = pInstData->stacktop;
1248     lpte->wStackMinimum = pInstData->stackmin;
1249     lpte->wStackBottom  = pInstData->stackbottom;
1250     lpte->wcEvents      = pTask->nEvents;
1251     lpte->hQueue        = pTask->hQueue;
1252     strncpy( lpte->szModule, pTask->module_name, 8 );
1253     lpte->szModule[8]   = '\0';
1254     lpte->wPSPOffset    = 0x100;  /*??*/
1255     lpte->hNext         = pTask->hNext;
1256     return TRUE;
1257 }
1258
1259
1260 /***********************************************************************
1261  *           TaskFindHandle   (TOOLHELP.65)
1262  */
1263 BOOL16 TaskFindHandle( TASKENTRY *lpte, HTASK16 hTask )
1264 {
1265     lpte->hNext = hTask;
1266     return TaskNext( lpte );
1267 }
1268
1269
1270 /***********************************************************************
1271  *           GetAppCompatFlags   (KERNEL.354) (USER32.205)
1272  */
1273 DWORD GetAppCompatFlags( HTASK32 hTask )
1274 {
1275     TDB *pTask;
1276
1277     if (!hTask) hTask = GetCurrentTask();
1278     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1279     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1280     return pTask->compat_flags;
1281 }