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
  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,0)
  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( HGLOBAL 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( name, "Compatibility", 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,"It's alive! Alive!!!\n");
 675     exit(1);
 676 }
 677
 678
 679 /***********************************************************************
 680  *           TASK_Reschedule
 681  *
 682  * This is where all the magic of task-switching happens!
 683  *
 684  * This function should only be called via the TASK_SCHEDULE() macro, to make
 685  * sure that all the context is saved correctly.
 686  */
 687 void TASK_Reschedule(void)
 688 {
 689     TDB *pOldTask = NULL, *pNewTask;
 690     HTASK hTask = 0;
 691
 692 #ifdef CONFIG_IPC
 693     dde_reschedule();
 694 #endif
 695       /* First check if there's a task to kill */
 696
 697     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 698     {
 699         TASK_DeleteTask( hTaskToKill );
 700         hTaskToKill = 0;
 701     }
 702
 703     /* Flush any X events that happened in the meantime */
 704
 705     EVENT_WaitXEvent( FALSE );
 706
 707     /* Find a task to yield to */
 708
 709     pOldTask = (TDB *)GlobalLock16( hCurrentTask );
 710     if (pOldTask && pOldTask->hYieldTo)
 711     {
 712         /* If a task is stored in hYieldTo of the current task (put there */
 713         /* by DirectedYield), yield to it only if it has events pending.  */
 714         hTask = pOldTask->hYieldTo;
 715         if (!(pNewTask = (TDB *)GlobalLock16( hTask )) || !pNewTask->nEvents)
 716             hTask = 0;
 717     }
 718
 719     while (!hTask)
 720     {
 721         /* Find a task that has an event pending */
 722
 723         hTask = hFirstTask;
 724         while (hTask)
 725         {
 726             pNewTask = (TDB *)GlobalLock16( hTask );
 727             if (pNewTask->nEvents) break;
 728             hTask = pNewTask->hNext;
 729         }
 730         if (hLockedTask && (hTask != hLockedTask)) hTask = 0;
 731         if (hTask) break;
 732
 733         /* No task found, wait for some events to come in */
 734
 735         EVENT_WaitXEvent( TRUE );
 736     }
 737
 738     if (hTask == hCurrentTask) return;  /* Nothing to do */
 739
 740     pNewTask = (TDB *)GlobalLock16( hTask );
 741     dprintf_task( stddeb, "Switching to task %04x (%.8s)\n",
 742                   hTask, pNewTask->module_name );
 743
 744       /* Save the stacks of the previous task (if any) */
 745
 746     if (pOldTask)
 747     {
 748         pOldTask->ss  = IF1632_Saved16_ss;
 749         pOldTask->sp  = IF1632_Saved16_sp;
 750         pOldTask->esp = IF1632_Saved32_esp;
 751     }
 752     else IF1632_Original32_esp = IF1632_Saved32_esp;
 753
 754      /* Make the task the last in the linked list (round-robin scheduling) */
 755
 756     pNewTask->priority++;
 757     TASK_UnlinkTask( hTask );
 758     TASK_LinkTask( hTask );
 759     pNewTask->priority--;
 760
 761       /* Switch to the new stack */
 762
 763     hCurrentTask = hTask;
 764     IF1632_Saved16_ss   = pNewTask->ss;
 765     IF1632_Saved16_sp   = pNewTask->sp;
 766     IF1632_Saved32_esp  = pNewTask->esp;
 767     IF1632_Stack32_base = WIN16_GlobalLock16( pNewTask->hStack32 );
 768 }
 769
 770
 771 /***********************************************************************
 772  *           InitTask  (KERNEL.91)
 773  */
 774 #ifdef WINELIB
 775 void InitTask(void)
 776 #else
 777 void InitTask( SIGCONTEXT *context )
 778 #endif
 779 {
 780     TDB *pTask;
 781     NE_MODULE *pModule;
 782     SEGTABLEENTRY *pSegTable;
 783     INSTANCEDATA *pinstance;
 784     LONG stacklow, stackhi;
 785
 786 #ifndef WINELIB
 787     EAX_reg(context) = 0;
 788 #endif
 789     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return;
 790     if (!(pModule = MODULE_GetPtr( pTask->hModule ))) return;
 791
 792 #ifndef WINELIB
 793     NE_InitializeDLLs( pTask->hModule );
 794
 795     /* Registers on return are:
 796      * ax     1 if OK, 0 on error
 797      * cx     stack limit in bytes
 798      * dx     cmdShow parameter
 799      * si     instance handle of the previous instance
 800      * di     instance handle of the new task
 801      * es:bx  pointer to command-line inside PSP
 802      */
 803     EAX_reg(context) = 1;
 804     EBX_reg(context) = 0x81;
 805     ECX_reg(context) = pModule->stack_size;
 806     EDX_reg(context) = pTask->nCmdShow;
 807     ESI_reg(context) = (DWORD)pTask->hPrevInstance;
 808     EDI_reg(context) = (DWORD)pTask->hInstance;
 809     ES_reg (context) = (WORD)pTask->hPDB;
 810
 811     /* Initialize the local heap */
 812     if ( pModule->heap_size )
 813     {
 814         LocalInit( pTask->hInstance, 0, pModule->heap_size );
 815     }
 816 #endif
 817
 818     /* Initialize the INSTANCEDATA structure */
 819     pSegTable = NE_SEG_TABLE( pModule );
 820     stacklow = pSegTable[pModule->ss - 1].minsize;
 821     stackhi  = stacklow + pModule->stack_size;
 822     if (stackhi > 0xffff) stackhi = 0xffff;
 823     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 824     pinstance->stackbottom = stackhi; /* yup, that's right. Confused me too. */
 825     pinstance->stacktop    = stacklow;
 826 #ifndef WINELIB
 827     pinstance->stackmin    = IF1632_Saved16_sp;
 828 #endif
 829 }
 830
 831
 832 /***********************************************************************
 833  *           WaitEvent  (KERNEL.30)
 834  */
 835 BOOL WaitEvent( HTASK hTask )
 836 {
 837     TDB *pTask;
 838
 839     if (!hTask) hTask = hCurrentTask;
 840     pTask = (TDB *)GlobalLock16( hTask );
 841     if (pTask->nEvents > 0)
 842     {
 843         pTask->nEvents--;
 844         return FALSE;
 845     }
 846     TASK_SCHEDULE();
 847     /* When we get back here, we have an event */
 848     if (pTask->nEvents > 0) pTask->nEvents--;
 849     else fprintf( stderr, "WaitEvent: reschedule returned without event\n" );
 850     return TRUE;
 851 }
 852
 853
 854 /***********************************************************************
 855  *           PostEvent  (KERNEL.31)
 856  */
 857 void PostEvent( HTASK hTask )
 858 {
 859     TDB *pTask;
 860
 861     if (!hTask) hTask = hCurrentTask;
 862     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 863     pTask->nEvents++;
 864 }
 865
 866
 867 /***********************************************************************
 868  *           SetPriority  (KERNEL.32)
 869  */
 870 void SetPriority( HTASK hTask, int delta )
 871 {
 872     TDB *pTask;
 873     int newpriority;
 874
 875     if (!hTask) hTask = hCurrentTask;
 876     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return;
 877     newpriority = pTask->priority + delta;
 878     if (newpriority < -32) newpriority = -32;
 879     else if (newpriority > 15) newpriority = 15;
 880
 881     pTask->priority = newpriority + 1;
 882     TASK_UnlinkTask( hTask );
 883     TASK_LinkTask( hTask );
 884     pTask->priority--;
 885 }
 886
 887
 888 /***********************************************************************
 889  *           LockCurrentTask  (KERNEL.33)
 890  */
 891 HTASK LockCurrentTask( BOOL bLock )
 892 {
 893     if (bLock) hLockedTask = hCurrentTask;
 894     else hLockedTask = 0;
 895     return hLockedTask;
 896 }
 897
 898
 899 /***********************************************************************
 900  *           IsTaskLocked  (KERNEL.122)
 901  */
 902 HTASK IsTaskLocked(void)
 903 {
 904     return hLockedTask;
 905 }
 906
 907
 908 /***********************************************************************
 909  *           OldYield  (KERNEL.117)
 910  */
 911 void OldYield(void)
 912 {
 913     TDB *pCurTask;
 914
 915     pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 916     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 917     TASK_SCHEDULE();
 918     if (pCurTask) pCurTask->nEvents--;
 919 }
 920
 921
 922 /***********************************************************************
 923  *           DirectedYield  (KERNEL.150)
 924  */
 925 void DirectedYield( HTASK hTask )
 926 {
 927     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 928     pCurTask->hYieldTo = hTask;
 929     OldYield();
 930 }
 931
 932
 933 /***********************************************************************
 934  *           UserYield  (USER.332)
 935  */
 936 void UserYield(void)
 937 {
 938     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 939     MESSAGEQUEUE *queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 940     /* Handle sent messages */
 941     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
 942         QUEUE_ReceiveMessage( queue );
 943
 944     OldYield();
 945
 946     queue = (MESSAGEQUEUE *)GlobalLock16( pCurTask->hQueue );
 947     if (queue && (queue->wakeBits & QS_SENDMESSAGE))
 948         QUEUE_ReceiveMessage( queue );
 949 }
 950
 951
 952 /***********************************************************************
 953  *           Yield  (KERNEL.29)
 954  */
 955 void Yield(void)
 956 {
 957     TDB *pCurTask = (TDB *)GlobalLock16( hCurrentTask );
 958     if (pCurTask) pCurTask->hYieldTo = 0;
 959     if (pCurTask && pCurTask->hQueue) UserYield();
 960     else OldYield();
 961 }
 962
 963
 964 /***********************************************************************
 965  *           MakeProcInstance16  (KERNEL.51)
 966  */
 967 FARPROC16 MakeProcInstance16( FARPROC16 func, HANDLE16 hInstance )
 968 {
 969 #ifdef WINELIB
 970     return func; /* func can be called directly in Winelib */
 971 #else
 972     BYTE *thunk;
 973     SEGPTR thunkaddr;
 974
 975     thunkaddr = TASK_AllocThunk( hCurrentTask );
 976     if (!thunkaddr) return (FARPROC16)0;
 977     thunk = PTR_SEG_TO_LIN( thunkaddr );
 978
 979     dprintf_task( stddeb, "MakeProcInstance(%08lx,%04x): got thunk %08lx\n",
 980                   (DWORD)func, hInstance, (DWORD)thunkaddr );
 981
 982     *thunk++ = 0xb8;    /* movw instance, %ax */
 983     *thunk++ = (BYTE)(hInstance & 0xff);
 984     *thunk++ = (BYTE)(hInstance >> 8);
 985     *thunk++ = 0xea;    /* ljmp func */
 986     *(DWORD *)thunk = (DWORD)func;
 987     return (FARPROC16)thunkaddr;
 988 #endif
 989 }
 990
 991
 992 /***********************************************************************
 993  *           FreeProcInstance16  (KERNEL.52)
 994  */
 995 void FreeProcInstance16( FARPROC16 func )
 996 {
 997 #ifndef WINELIB
 998     dprintf_task( stddeb, "FreeProcInstance(%08lx)\n", (DWORD)func );
 999     TASK_FreeThunk( hCurrentTask, (SEGPTR)func );
1000 #endif
1001 }
1002
1003
1004 /**********************************************************************
1005  *          GetCodeHandle    (KERNEL.93)
1006  */
1007 HANDLE GetCodeHandle( FARPROC16 proc )
1008 {
1009 #ifndef WINELIB32
1010     HANDLE handle;
1011     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
1012
1013     /* Return the code segment containing 'proc'. */
1014     /* Not sure if this is really correct (shouldn't matter that much). */
1015
1016     /* Check if it is really a thunk */
1017     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
1018         handle = GlobalHandle16( thunk[6] + (thunk[7] << 8) );
1019     else
1020         handle = GlobalHandle16( HIWORD(proc) );
1021
1022     return handle;
1023 #else
1024     return (HANDLE)proc;
1025 #endif
1026 }
1027
1028
1029 /***********************************************************************
1030  *           SetTaskQueue  (KERNEL.34)
1031  */
1032 HQUEUE SetTaskQueue( HANDLE hTask, HQUEUE hQueue )
1033 {
1034     HQUEUE hPrev;
1035     TDB *pTask;
1036
1037     if (!hTask) hTask = hCurrentTask;
1038     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1039
1040     hPrev = pTask->hQueue;
1041     pTask->hQueue = hQueue;
1042
1043     TIMER_SwitchQueue( hPrev, hQueue );
1044
1045     return hPrev;
1046 }
1047
1048
1049 /***********************************************************************
1050  *           GetTaskQueue  (KERNEL.35)
1051  */
1052 HQUEUE16 GetTaskQueue( HTASK16 hTask )
1053 {
1054     TDB *pTask;
1055
1056     if (!hTask) hTask = hCurrentTask;
1057     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return 0;
1058     return pTask->hQueue;
1059 }
1060
1061
1062 /***********************************************************************
1063  *           GetTaskQueueDS  (KERNEL.118)
1064  */
1065 #ifndef WINELIB
1066 void GetTaskQueueDS( SIGCONTEXT *context )
1067 {
1068     DS_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1069 }
1070 #endif  /* WINELIB */
1071
1072
1073 /***********************************************************************
1074  *           GetTaskQueueES  (KERNEL.119)
1075  */
1076 #ifndef WINELIB
1077 void GetTaskQueueES( SIGCONTEXT *context )
1078 {
1079     ES_reg(context) = GlobalHandleToSel( GetTaskQueue(0) );
1080 }
1081 #endif  /* WINELIB */
1082
1083
1084 /***********************************************************************
1085  *           GetCurrentTask   (KERNEL.36)
1086  */
1087 HTASK16 GetCurrentTask(void)
1088 {
1089     return hCurrentTask;
1090 }
1091
1092 DWORD WIN16_GetCurrentTask(void)
1093 {
1094     /* This is the version used by relay code; the first task is */
1095     /* returned in the high word of the result */
1096     return MAKELONG( hCurrentTask, hFirstTask );
1097 }
1098
1099
1100 /***********************************************************************
1101  *           GetCurrentPDB   (KERNEL.37)
1102  */
1103 HANDLE GetCurrentPDB(void)
1104 {
1105     TDB *pTask;
1106
1107     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1108     return pTask->hPDB;
1109 }
1110
1111
1112 /***********************************************************************
1113  *           GetInstanceData   (KERNEL.54)
1114  */
1115 int GetInstanceData( HANDLE instance, WORD buffer, int len )
1116 {
1117     char *ptr = (char *)GlobalLock16( instance );
1118     if (!ptr || !len) return 0;
1119     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1120     memcpy( (char *)GlobalLock16(CURRENT_DS) + buffer, ptr + buffer, len );
1121     return len;
1122 }
1123
1124
1125 /***********************************************************************
1126  *           SetErrorMode   (KERNEL.107)
1127  */
1128 UINT SetErrorMode( UINT mode )
1129 {
1130     TDB *pTask;
1131     UINT oldMode;
1132
1133     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1134     oldMode = pTask->error_mode;
1135     pTask->error_mode = mode;
1136     return oldMode;
1137 }
1138
1139
1140 /***********************************************************************
1141  *           GetDOSEnvironment   (KERNEL.131)
1142  */
1143 SEGPTR GetDOSEnvironment(void)
1144 {
1145     TDB *pTask;
1146
1147     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1148     return (SEGPTR)WIN16_GlobalLock16( pTask->pdb.environment );
1149 }
1150
1151
1152 /***********************************************************************
1153  *           GetNumTasks   (KERNEL.152)
1154  */
1155 WORD GetNumTasks(void)
1156 {
1157     return nTaskCount;
1158 }
1159
1160
1161 /***********************************************************************
1162  *           GetTaskDS   (KERNEL.155)
1163  */
1164 HINSTANCE16 GetTaskDS(void)
1165 {
1166     TDB *pTask;
1167
1168     if (!(pTask = (TDB *)GlobalLock16( hCurrentTask ))) return 0;
1169     return pTask->hInstance;
1170 }
1171
1172
1173 /***********************************************************************
1174  *           IsTask   (KERNEL.320)
1175  */
1176 BOOL IsTask( HTASK hTask )
1177 {
1178     TDB *pTask;
1179
1180     if (!(pTask = (TDB *)GlobalLock16( hTask ))) return FALSE;
1181     if (GlobalSize16( hTask ) < sizeof(TDB)) return FALSE;
1182     return (pTask->magic == TDB_MAGIC);
1183 }
1184
1185
1186 /***********************************************************************
1187  *           GetExePtr   (KERNEL.133)
1188  */
1189 HMODULE16 GetExePtr( HANDLE16 handle )
1190 {
1191     char *ptr;
1192     HTASK16 hTask;
1193     HANDLE16 owner;
1194
1195       /* Check for module handle */
1196
1197     if (!(ptr = GlobalLock16( handle ))) return 0;
1198     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return handle;
1199
1200       /* Check the owner for module handle */
1201
1202     owner = FarGetOwner( handle );
1203     if (!(ptr = GlobalLock16( owner ))) return 0;
1204     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return owner;
1205
1206       /* Search for this handle and its owner inside all tasks */
1207
1208     hTask = hFirstTask;
1209     while (hTask)
1210     {
1211         TDB *pTask = (TDB *)GlobalLock16( hTask );
1212         if ((hTask == handle) ||
1213             (pTask->hInstance == handle) ||
1214             (pTask->hQueue == handle) ||
1215             (pTask->hPDB == handle)) return pTask->hModule;
1216         if ((hTask == owner) ||
1217             (pTask->hInstance == owner) ||
1218             (pTask->hQueue == owner) ||
1219             (pTask->hPDB == owner)) return pTask->hModule;
1220         hTask = pTask->hNext;
1221     }
1222     return 0;
1223 }
1224
1225
1226 /***********************************************************************
1227  *           TaskFirst   (TOOLHELP.63)
1228  */
1229 BOOL16 TaskFirst( TASKENTRY *lpte )
1230 {
1231     lpte->hNext = hFirstTask;
1232     return TaskNext( lpte );
1233 }
1234
1235
1236 /***********************************************************************
1237  *           TaskNext   (TOOLHELP.64)
1238  */
1239 BOOL16 TaskNext( TASKENTRY *lpte )
1240 {
1241     TDB *pTask;
1242     INSTANCEDATA *pInstData;
1243
1244     dprintf_toolhelp( stddeb, "TaskNext(%p): task=%04x\n", lpte, lpte->hNext );
1245     if (!lpte->hNext) return FALSE;
1246     pTask = (TDB *)GlobalLock16( lpte->hNext );
1247     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1248     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1249     lpte->hTask         = lpte->hNext;
1250     lpte->hTaskParent   = pTask->hParent;
1251     lpte->hInst         = pTask->hInstance;
1252     lpte->hModule       = pTask->hModule;
1253     lpte->wSS           = pTask->ss;
1254     lpte->wSP           = pTask->sp;
1255     lpte->wStackTop     = pInstData->stacktop;
1256     lpte->wStackMinimum = pInstData->stackmin;
1257     lpte->wStackBottom  = pInstData->stackbottom;
1258     lpte->wcEvents      = pTask->nEvents;
1259     lpte->hQueue        = pTask->hQueue;
1260     strncpy( lpte->szModule, pTask->module_name, 8 );
1261     lpte->szModule[8]   = '\0';
1262     lpte->wPSPOffset    = 0x100;  /*??*/
1263     lpte->hNext         = pTask->hNext;
1264     return TRUE;
1265 }
1266
1267
1268 /***********************************************************************
1269  *           TaskFindHandle   (TOOLHELP.65)
1270  */
1271 BOOL16 TaskFindHandle( TASKENTRY *lpte, HTASK16 hTask )
1272 {
1273     lpte->hNext = hTask;
1274     return TaskNext( lpte );
1275 }
1276
1277
1278 /***********************************************************************
1279  *           GetAppCompatFlags   (KERNEL.354) (USER32.205)
1280  */
1281 DWORD GetAppCompatFlags( HTASK32 hTask )
1282 {
1283     TDB *pTask;
1284
1285     if (!hTask) hTask = GetCurrentTask();
1286     if (!(pTask=(TDB *)GlobalLock16( (HTASK16)hTask ))) return 0;
1287     if (GlobalSize16(hTask) < sizeof(TDB)) return 0;
1288     return pTask->compat_flags;
1289 }