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 #include "windows.h"
  11 #include "task.h"
  12 #include "callback.h"
  13 #include "dos_fs.h"
  14 #include "debugger.h"
  15 #include "global.h"
  16 #include "instance.h"
  17 #include "message.h"
  18 #include "miscemu.h"
  19 #include "module.h"
  20 #include "neexe.h"
  21 #include "options.h"
  22 #include "selectors.h"
  23 #include "toolhelp.h"
  24 #include "stddebug.h"
  25 #include "debug.h"
  26 #include "dde_proc.h"
  27
  28   /* Min. number of thunks allocated when creating a new segment */
  29 #define MIN_THUNKS  32
  30
  31   /* 32-bit stack size for each task */
  32   /* Must not be greater than 64k, or MAKE_SEGPTR won't work */
  33 #define STACK32_SIZE 0x10000
  34
  35 /* ------ Internal variables ------ */
  36
  37 static HTASK hFirstTask = 0;
  38 static HTASK hCurrentTask = 0;
  39 static HTASK hTaskToKill = 0;
  40 static HTASK hLockedTask = 0;
  41 static WORD nTaskCount = 0;
  42 static HANDLE hDOSEnvironment = 0;
  43
  44 /* ------ Internal declarations ------ */
  45
  46   /* TASK_Reschedule() 16-bit entry point */
  47 static FARPROC TASK_RescheduleProc;
  48
  49 #ifdef WINELIB
  50 #define TASK_SCHEDULE()  TASK_Reschedule();
  51 #else
  52 #define TASK_SCHEDULE()  CallTo16_word_(TASK_RescheduleProc,0)
  53 #endif
  54
  55 static HANDLE TASK_CreateDOSEnvironment(void);
  56
  57 /***********************************************************************
  58  *           TASK_Init
  59  */
  60 BOOL TASK_Init(void)
  61 {
  62     TASK_RescheduleProc = (FARPROC)GetWndProcEntry16( "TASK_Reschedule" );
  63     if (!(hDOSEnvironment = TASK_CreateDOSEnvironment()))
  64         fprintf( stderr, "Not enough memory for DOS Environment\n" );
  65     return (hDOSEnvironment != 0);
  66 }
  67
  68
  69 /***********************************************************************
  70  *           TASK_CreateDOSEnvironment
  71  *
  72  * Create the original DOS environment.
  73  */
  74 static HANDLE TASK_CreateDOSEnvironment(void)
  75 {
  76     static const char program_name[] = "KRNL386.EXE";
  77     char **e, *p;
  78     int initial_size, size;
  79     HANDLE handle;
  80
  81     extern char **environ;
  82     extern char WindowsDirectory[], SystemDirectory[];
  83
  84     /* DOS environment format:
  85      * ASCIIZ   string 1
  86      * ASCIIZ   string 2
  87      * ...
  88      * ASCIIZ   string n
  89      * ASCIIZ   PATH=xxx
  90      * ASCIIZ   windir=xxx
  91      * BYTE     0
  92      * WORD     1
  93      * ASCIIZ   program name (e.g. C:\WINDOWS\SYSTEM\KRNL386.EXE)
  94      */
  95
  96     /* First compute the size of the fixed part of the environment */
  97
  98     initial_size = 5 +                            /* PATH= */
  99                    strlen(WindowsPath) + 1 +      /* path value */
 100                    7 +                            /* windir= */
 101                    strlen(WindowsDirectory) + 1 + /* windir value */
 102                    1 +                            /* BYTE 0 at end */
 103                    sizeof(WORD) +                 /* WORD 1 */
 104                    strlen(SystemDirectory) + 1 +  /* program directory */
 105                    strlen(program_name) + 1;      /* program name */
 106
 107     /* Compute the total size of the Unix environment (except path) */
 108
 109     for (e = environ, size = initial_size; *e; e++)
 110     {
 111         if (strncasecmp(*e, "path=", 5))
 112         {
 113             int len = strlen(*e) + 1;
 114             if (size + len >= 32767)
 115             {
 116                 fprintf( stderr, "Warning: environment larger than 32k.\n" );
 117                 break;
 118             }
 119             size += len;
 120         }
 121     }
 122
 123
 124     /* Now allocate the environment */
 125
 126     if (!(handle = GlobalAlloc( GMEM_FIXED, size ))) return 0;
 127     p = (char *)GlobalLock( handle );
 128
 129     /* And fill it with the Unix environment */
 130
 131     for (e = environ, size = initial_size; *e; e++)
 132     {
 133         if (strncasecmp(*e, "path=", 5))
 134         {
 135             int len = strlen(*e) + 1;
 136             if (size + len >= 32767) break;
 137             strcpy( p, *e );
 138             size += len;
 139             p    += len;
 140         }
 141     }
 142
 143     /* Now add the path and Windows directory */
 144
 145     strcpy( p, "PATH=" );
 146     strcat( p, WindowsPath );
 147     p += strlen(p) + 1;
 148
 149     strcpy( p, "windir=" );
 150     strcat( p, WindowsDirectory );
 151     p += strlen(p) + 1;
 152
 153     /* Now add the program name */
 154
 155     *p++ = '\0';
 156     *(WORD *)p = 1;
 157     p += sizeof(WORD);
 158     strcpy( p, SystemDirectory );
 159     strcat( p, "\\" );
 160     strcat( p, program_name );
 161
 162     /* Display it */
 163
 164     p = (char *) GlobalLock( handle );
 165     dprintf_task(stddeb, "Master DOS environment at %p\n", p);
 166     for (; *p; p += strlen(p) + 1) dprintf_task(stddeb, "    %s\n", p);
 167     dprintf_task( stddeb, "Progname: %s\n", p+3 );
 168
 169     return handle;
 170 }
 171
 172
 173 /***********************************************************************
 174  *           TASK_LinkTask
 175  */
 176 static void TASK_LinkTask( HTASK hTask )
 177 {
 178     HTASK *prevTask;
 179     TDB *pTask;
 180
 181     if (!(pTask = (TDB *)GlobalLock( hTask ))) return;
 182     prevTask = &hFirstTask;
 183     while (*prevTask)
 184     {
 185         TDB *prevTaskPtr = (TDB *)GlobalLock( *prevTask );
 186         if (prevTaskPtr->priority >= pTask->priority) break;
 187         prevTask = &prevTaskPtr->hNext;
 188     }
 189     pTask->hNext = *prevTask;
 190     *prevTask = hTask;
 191     nTaskCount++;
 192 }
 193
 194
 195 /***********************************************************************
 196  *           TASK_UnlinkTask
 197  */
 198 static void TASK_UnlinkTask( HTASK hTask )
 199 {
 200     HTASK *prevTask;
 201     TDB *pTask;
 202
 203     prevTask = &hFirstTask;
 204     while (*prevTask && (*prevTask != hTask))
 205     {
 206         pTask = (TDB *)GlobalLock( *prevTask );
 207         prevTask = &pTask->hNext;
 208     }
 209     if (*prevTask)
 210     {
 211         pTask = (TDB *)GlobalLock( *prevTask );
 212         *prevTask = pTask->hNext;
 213         pTask->hNext = 0;
 214         nTaskCount--;
 215     }
 216 }
 217
 218
 219 /***********************************************************************
 220  *           TASK_CreateThunks
 221  *
 222  * Create a thunk free-list in segment 'handle', starting from offset 'offset'
 223  * and containing 'count' entries.
 224  */
 225 static void TASK_CreateThunks( HGLOBAL handle, WORD offset, WORD count )
 226 {
 227     int i;
 228     WORD free;
 229     THUNKS *pThunk;
 230
 231     pThunk = (THUNKS *)((BYTE *)GlobalLock( handle ) + offset);
 232     pThunk->next = 0;
 233     pThunk->magic = THUNK_MAGIC;
 234     pThunk->free = (int)&pThunk->thunks - (int)pThunk;
 235     free = pThunk->free;
 236     for (i = 0; i < count-1; i++)
 237     {
 238         free += 8;  /* Offset of next thunk */
 239         pThunk->thunks[4*i] = free;
 240     }
 241     pThunk->thunks[4*i] = 0;  /* Last thunk */
 242 }
 243
 244
 245 /***********************************************************************
 246  *           TASK_AllocThunk
 247  *
 248  * Allocate a thunk for MakeProcInstance().
 249  */
 250 static SEGPTR TASK_AllocThunk( HTASK hTask )
 251 {
 252     TDB *pTask;
 253     THUNKS *pThunk;
 254     WORD sel, base;
 255
 256     if (!(pTask = (TDB *)GlobalLock( hTask ))) return 0;
 257     sel = pTask->hCSAlias;
 258     pThunk = &pTask->thunks;
 259     base = (int)pThunk - (int)pTask;
 260     while (!pThunk->free)
 261     {
 262         sel = pThunk->next;
 263         if (!sel)  /* Allocate a new segment */
 264         {
 265             sel = GLOBAL_Alloc( GMEM_FIXED, sizeof(THUNKS) + (MIN_THUNKS-1)*8,
 266                                 pTask->hPDB, TRUE, FALSE, FALSE );
 267             if (!sel) return (SEGPTR)0;
 268             TASK_CreateThunks( sel, 0, MIN_THUNKS );
 269             pThunk->next = sel;
 270         }
 271         pThunk = (THUNKS *)GlobalLock( sel );
 272         base = 0;
 273     }
 274     base += pThunk->free;
 275     pThunk->free = *(WORD *)((BYTE *)pThunk + pThunk->free);
 276     return MAKELONG( base, sel );
 277 }
 278
 279
 280 /***********************************************************************
 281  *           TASK_FreeThunk
 282  *
 283  * Free a MakeProcInstance() thunk.
 284  */
 285 static BOOL TASK_FreeThunk( HTASK hTask, SEGPTR thunk )
 286 {
 287     TDB *pTask;
 288     THUNKS *pThunk;
 289     WORD sel, base;
 290
 291     if (!(pTask = (TDB *)GlobalLock( hTask ))) return 0;
 292     sel = pTask->hCSAlias;
 293     pThunk = &pTask->thunks;
 294     base = (int)pThunk - (int)pTask;
 295     while (sel && (sel != HIWORD(thunk)))
 296     {
 297         sel = pThunk->next;
 298         pThunk = (THUNKS *)GlobalLock( sel );
 299         base = 0;
 300     }
 301     if (!sel) return FALSE;
 302     *(WORD *)((BYTE *)pThunk + LOWORD(thunk) - base) = pThunk->free;
 303     pThunk->free = LOWORD(thunk) - base;
 304     return TRUE;
 305 }
 306
 307
 308 /***********************************************************************
 309  *           TASK_CallToStart
 310  *
 311  * 32-bit entry point for a new task. This function is responsible for
 312  * setting up the registers and jumping to the 16-bit entry point.
 313  */
 314 static void TASK_CallToStart(void)
 315 {
 316     int cs_reg, ds_reg, ip_reg;
 317     TDB *pTask = (TDB *)GlobalLock( hCurrentTask );
 318     NE_MODULE *pModule = (NE_MODULE *)GlobalLock( pTask->hModule );
 319     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
 320
 321     /* Registers at initialization must be:
 322      * ax   zero
 323      * bx   stack size in bytes
 324      * cx   heap size in bytes
 325      * si   previous app instance
 326      * di   current app instance
 327      * bp   zero
 328      * es   selector to the PSP
 329      * ds   dgroup of the application
 330      * ss   stack selector
 331      * sp   top of the stack
 332      */
 333
 334     cs_reg = pSegTable[pModule->cs - 1].selector;
 335     ip_reg = pModule->ip;
 336     ds_reg = pSegTable[pModule->dgroup - 1].selector;
 337 #ifndef WINELIB
 338 /* JBP: I doubt a CallTo16_regs_ is possible in libwine.a, and IF1632 is not
 339  *      allowed.
 340  */
 341     IF1632_Saved16_ss = pTask->ss;
 342     IF1632_Saved16_sp = pTask->sp;
 343     dprintf_task( stddeb, "Starting main program: cs:ip=%04x:%04x ds=%04x ss:sp=%04x:%04x\n",
 344                  cs_reg, ip_reg, ds_reg,
 345                  IF1632_Saved16_ss, IF1632_Saved16_sp);
 346
 347     CallTo16_regs_( (FARPROC)(cs_reg << 16 | ip_reg), ds_reg,
 348                    pTask->hPDB /*es*/, 0 /*bp*/, 0 /*ax*/,
 349                    pModule->stack_size /*bx*/, pModule->heap_size /*cx*/,
 350                    0 /*dx*/, 0 /*si*/, ds_reg /*di*/ );
 351 #else
 352     fprintf(stderr, "JBP: Ignoring main program: cs:ip=%04x:%04x ds=%04x ss:sp=%04x:%04x\n",
 353                  cs_reg, ip_reg, ds_reg,
 354                  pTask->ss, pTask->sp);
 355 #endif
 356     /* This should never return */
 357     fprintf( stderr, "TASK_CallToStart: Main program returned!\n" );
 358     TASK_KillCurrentTask( 1 );
 359 }
 360
 361
 362 /***********************************************************************
 363  *           TASK_CreateTask
 364  */
 365 HTASK TASK_CreateTask( HMODULE hModule, HANDLE hInstance, HANDLE hPrevInstance,
 366                        HANDLE hEnvironment, char *cmdLine, WORD cmdShow )
 367 {
 368     HTASK hTask;
 369     TDB *pTask;
 370     HANDLE hParentEnv;
 371     NE_MODULE *pModule;
 372     SEGTABLEENTRY *pSegTable;
 373     LPSTR name;
 374     char filename[256];
 375 #ifndef WINELIB32
 376     char *stack16Top, *stack32Top;
 377     STACK16FRAME *frame16;
 378     STACK32FRAME *frame32;
 379     extern DWORD CALL16_RetAddr_word;
 380 #endif
 381
 382     if (!(pModule = (NE_MODULE *)GlobalLock( hModule ))) return 0;
 383     pSegTable = NE_SEG_TABLE( pModule );
 384
 385       /* Allocate the task structure */
 386
 387     hTask = GLOBAL_Alloc( GMEM_FIXED | GMEM_ZEROINIT, sizeof(TDB),
 388                           hModule, FALSE, FALSE, FALSE );
 389     if (!hTask) return 0;
 390     pTask = (TDB *)GlobalLock( hTask );
 391
 392       /* Allocate the new environment block */
 393
 394     if (!(hParentEnv = hEnvironment))
 395     {
 396         TDB *pParent = (TDB *)GlobalLock( hCurrentTask );
 397         hParentEnv = pParent ? pParent->pdb.environment : hDOSEnvironment;
 398     }
 399     /* FIXME: do we really need to make a copy also when */
 400     /*        we don't use the parent environment? */
 401     if (!(hEnvironment = GlobalAlloc( GMEM_FIXED, GlobalSize( hParentEnv ) )))
 402     {
 403         GlobalFree( hTask );
 404         return 0;
 405     }
 406     memcpy( GlobalLock( hEnvironment ), GlobalLock( hParentEnv ),
 407             GlobalSize( hParentEnv ) );
 408
 409       /* Get current directory */
 410
 411     GetModuleFileName( hModule, filename, sizeof(filename) );
 412     name = strrchr(filename, '\\');
 413     if (name) *(name+1) = 0;
 414
 415       /* Fill the task structure */
 416
 417     pTask->nEvents       = 1;  /* So the task can be started */
 418     pTask->hSelf         = hTask;
 419     pTask->flags         = 0;
 420     pTask->version       = pModule->expected_version;
 421     pTask->hInstance     = hInstance;
 422     pTask->hPrevInstance = hPrevInstance;
 423     pTask->hModule       = hModule;
 424     pTask->hParent       = hCurrentTask;
 425 #ifdef WINELIB
 426     pTask->curdrive      = 'C' - 'A' + 0x80;
 427 #else
 428     pTask->curdrive      = filename[0] - 'A' + 0x80;
 429 #endif
 430     pTask->magic         = TDB_MAGIC;
 431     pTask->nCmdShow      = cmdShow;
 432     strcpy( pTask->curdir, filename+2 );
 433
 434       /* Create the thunks block */
 435
 436     TASK_CreateThunks( hTask, (int)&pTask->thunks - (int)pTask, 7 );
 437
 438       /* Copy the module name */
 439
 440     name = MODULE_GetModuleName( hModule );
 441     strncpy( pTask->module_name, name, sizeof(pTask->module_name) );
 442
 443       /* Fill the PDB */
 444
 445     pTask->pdb.int20 = 0x20cd;
 446     pTask->pdb.dispatcher[0] = 0x9a;  /* ljmp */
 447     *(DWORD *)&pTask->pdb.dispatcher[1] = MODULE_GetEntryPoint( GetModuleHandle("KERNEL"), 102 );  /* KERNEL.102 is DOS3Call() */
 448 #ifndef WINELIB
 449     pTask->pdb.savedint22 = INT_GetHandler( 0x22 );
 450     pTask->pdb.savedint23 = INT_GetHandler( 0x23 );
 451     pTask->pdb.savedint24 = INT_GetHandler( 0x24 );
 452 #endif
 453     pTask->pdb.environment = hEnvironment;
 454     strncpy( pTask->pdb.cmdLine + 1, cmdLine, 126 );
 455     pTask->pdb.cmdLine[127] = '\0';
 456     pTask->pdb.cmdLine[0] = strlen( pTask->pdb.cmdLine + 1 );
 457
 458       /* Get the compatibility flags */
 459
 460     pTask->compat_flags = GetProfileInt( name, "Compatibility", 0 );
 461
 462       /* Allocate a selector for the PDB */
 463
 464     pTask->hPDB = GLOBAL_CreateBlock( GMEM_FIXED, &pTask->pdb, sizeof(PDB),
 465                                       hModule, FALSE, FALSE, FALSE, NULL );
 466
 467       /* Allocate a code segment alias for the TDB */
 468
 469     pTask->hCSAlias = GLOBAL_CreateBlock( GMEM_FIXED, (void *)pTask,
 470                                           sizeof(TDB), pTask->hPDB, TRUE,
 471                                           FALSE, FALSE, NULL );
 472
 473       /* Set the owner of the environment block */
 474
 475     FarSetOwner( pTask->pdb.environment, pTask->hPDB );
 476
 477       /* Default DTA overwrites command-line */
 478
 479     pTask->dta = MAKELONG( (int)&pTask->pdb.cmdLine - (int)&pTask->pdb,
 480                            pTask->hPDB );
 481
 482       /* Allocate the 32-bit stack */
 483
 484 #ifndef WINELIB
 485     pTask->hStack32 = GLOBAL_Alloc( GMEM_FIXED, STACK32_SIZE, pTask->hPDB,
 486                                     FALSE, FALSE, FALSE );
 487
 488       /* Create the 32-bit stack frame */
 489
 490     *(DWORD *)GlobalLock(pTask->hStack32) = 0xDEADBEEF;
 491     stack32Top = (char*)GlobalLock(pTask->hStack32) + STACK32_SIZE;
 492     frame32 = (STACK32FRAME *)stack32Top - 1;
 493     frame32->saved_esp = (DWORD)stack32Top;
 494     frame32->edi = 0;
 495     frame32->esi = 0;
 496     frame32->edx = 0;
 497     frame32->ecx = 0;
 498     frame32->ebx = 0;
 499     frame32->ebp = 0;
 500     frame32->retaddr = (DWORD)TASK_CallToStart;
 501     frame32->codeselector = WINE_CODE_SELECTOR;
 502     pTask->esp = (DWORD)frame32;
 503
 504       /* Create the 16-bit stack frame */
 505
 506     pTask->ss = hInstance;
 507     pTask->sp = ((pModule->sp != 0) ? pModule->sp :
 508                  pSegTable[pModule->ss-1].minsize + pModule->stack_size) & ~1;
 509     stack16Top = (char *)PTR_SEG_OFF_TO_LIN( pTask->ss, pTask->sp );
 510     frame16 = (STACK16FRAME *)stack16Top - 1;
 511     frame16->saved_ss = 0; /*pTask->ss;*/
 512     frame16->saved_sp = 0; /*pTask->sp;*/
 513     frame16->ds = frame16->es = pTask->hInstance;
 514     frame16->entry_point = 0;
 515     frame16->ordinal_number = 24;  /* WINPROCS.24 is TASK_Reschedule */
 516     frame16->dll_id = 24; /* WINPROCS */
 517     frame16->bp = 0;
 518     frame16->ip = LOWORD( CALL16_RetAddr_word );
 519     frame16->cs = HIWORD( CALL16_RetAddr_word );
 520     pTask->sp -= sizeof(STACK16FRAME);
 521
 522       /* If there's no 16-bit stack yet, use a part of the new task stack */
 523       /* This is only needed to have a stack to switch from on the first  */
 524       /* call to DirectedYield(). */
 525
 526     if (!IF1632_Saved16_ss)
 527     {
 528         IF1632_Saved16_ss = pTask->ss;
 529         IF1632_Saved16_sp = pTask->sp;
 530     }
 531
 532       /* Add a breakpoint at the start of the task */
 533
 534     if (Options.debug)
 535     {
 536         DBG_ADDR addr = { pSegTable[pModule->cs-1].selector, pModule->ip };
 537         fprintf( stderr, "Task '%s': ", name );
 538         DEBUG_AddBreakpoint( &addr );
 539     }
 540 #endif
 541
 542       /* Add the task to the linked list */
 543
 544     TASK_LinkTask( hTask );
 545
 546     dprintf_task( stddeb, "CreateTask: module='%s' cmdline='%s' task="NPFMT"\n",
 547                   name, cmdLine, hTask );
 548
 549     return hTask;
 550 }
 551
 552
 553 /***********************************************************************
 554  *           TASK_DeleteTask
 555  */
 556 static void TASK_DeleteTask( HTASK hTask )
 557 {
 558     TDB *pTask;
 559
 560     if (!(pTask = (TDB *)GlobalLock( hTask ))) return;
 561
 562       /* Free the task module */
 563
 564     FreeModule( pTask->hModule );
 565
 566       /* Free all memory used by this task (including the 32-bit stack, */
 567       /* the environment block and the thunk segments). */
 568
 569     GlobalFreeAll( pTask->hPDB );
 570
 571       /* Free message queue */
 572
 573     MSG_DeleteMsgQueue( pTask->hQueue );
 574
 575       /* Free the selector aliases */
 576
 577     GLOBAL_FreeBlock( pTask->hCSAlias );
 578     GLOBAL_FreeBlock( pTask->hPDB );
 579
 580       /* Free the task structure itself */
 581
 582     GlobalFree( hTask );
 583 }
 584
 585
 586 /***********************************************************************
 587  *           TASK_KillCurrentTask
 588  *
 589  * Kill the currently running task. As it's not possible to kill the
 590  * current task like this, it is simply marked for destruction, and will
 591  * be killed when either TASK_Reschedule or this function is called again
 592  * in the context of another task.
 593  */
 594 void TASK_KillCurrentTask( int exitCode )
 595 {
 596     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 597     {
 598         /* If another task is already marked for destruction, */
 599         /* we call kill it now, as we are in another context. */
 600         TASK_DeleteTask( hTaskToKill );
 601     }
 602
 603     if (nTaskCount <= 1)
 604     {
 605         dprintf_task( stddeb, "Killing the last task, exiting\n" );
 606         exit(0);
 607     }
 608
 609     /* Remove the task from the list to be sure we never switch back to it */
 610     TASK_UnlinkTask( hCurrentTask );
 611
 612     hTaskToKill = hCurrentTask;
 613     hLockedTask = 0;
 614
 615     Yield();
 616     /* We should never return from this Yield() */
 617
 618     fprintf(stderr,"It's alive! Alive!!!\n");
 619     exit(1);
 620 }
 621
 622
 623 /***********************************************************************
 624  *           TASK_Reschedule
 625  *
 626  * This is where all the magic of task-switching happens!
 627  *
 628  * This function should only be called via the TASK_SCHEDULE() macro, to make
 629  * sure that all the context is saved correctly.
 630  */
 631 void TASK_Reschedule(void)
 632 {
 633     TDB *pOldTask = NULL, *pNewTask;
 634     HTASK hTask = 0;
 635
 636 #ifdef CONFIG_IPC
 637     dde_reschedule();
 638 #endif
 639       /* First check if there's a task to kill */
 640
 641     if (hTaskToKill && (hTaskToKill != hCurrentTask))
 642     {
 643         TASK_DeleteTask( hTaskToKill );
 644         hTaskToKill = 0;
 645     }
 646
 647       /* If current task is locked, simply return */
 648
 649     if (hLockedTask) return;
 650
 651       /* Find a task to yield to */
 652
 653     pOldTask = (TDB *)GlobalLock( hCurrentTask );
 654     if (pOldTask && pOldTask->hYieldTo)
 655     {
 656         /* If a task is stored in hYieldTo of the current task (put there */
 657         /* by DirectedYield), yield to it only if it has events pending.  */
 658         hTask = pOldTask->hYieldTo;
 659         if (!(pNewTask = (TDB *)GlobalLock( hTask )) || !pNewTask->nEvents)
 660             hTask = 0;
 661     }
 662
 663     if (!hTask)
 664     {
 665         hTask = hFirstTask;
 666         while (hTask)
 667         {
 668             pNewTask = (TDB *)GlobalLock( hTask );
 669             if (pNewTask->nEvents && (hTask != hCurrentTask)) break;
 670             hTask = pNewTask->hNext;
 671         }
 672     }
 673
 674      /* If there's a task to kill, switch to any other task, */
 675      /* even if it doesn't have events pending. */
 676
 677     if (!hTask && hTaskToKill) hTask = hFirstTask;
 678
 679     if (!hTask) return;  /* Do nothing */
 680
 681     pNewTask = (TDB *)GlobalLock( hTask );
 682     dprintf_task( stddeb, "Switching to task "NPFMT" (%.8s)\n",
 683                   hTask, pNewTask->module_name );
 684
 685       /* Save the stacks of the previous task (if any) */
 686
 687 #ifndef WINELIB /* FIXME: JBP: IF1632 not allowed in libwine.a */
 688     if (pOldTask)
 689     {
 690         pOldTask->ss  = IF1632_Saved16_ss;
 691         pOldTask->sp  = IF1632_Saved16_sp;
 692         pOldTask->esp = IF1632_Saved32_esp;
 693     }
 694     else IF1632_Original32_esp = IF1632_Saved32_esp;
 695 #endif
 696
 697      /* Make the task the last in the linked list (round-robin scheduling) */
 698
 699     pNewTask->priority++;
 700     TASK_UnlinkTask( hTask );
 701     TASK_LinkTask( hTask );
 702     pNewTask->priority--;
 703
 704       /* Switch to the new stack */
 705
 706     hCurrentTask = hTask;
 707 #ifndef WINELIB /* FIXME: JBP: IF1632 not allowed in libwine.a */
 708     IF1632_Saved16_ss   = pNewTask->ss;
 709     IF1632_Saved16_sp   = pNewTask->sp;
 710     IF1632_Saved32_esp  = pNewTask->esp;
 711     IF1632_Stack32_base = WIN16_GlobalLock( pNewTask->hStack32 );
 712 #endif
 713 }
 714
 715
 716 /***********************************************************************
 717  *           InitTask  (KERNEL.91)
 718  */
 719 void InitTask( struct sigcontext_struct context )
 720 {
 721     static int firstTask = 1;
 722     TDB *pTask;
 723     NE_MODULE *pModule;
 724     SEGTABLEENTRY *pSegTable;
 725     INSTANCEDATA *pinstance;
 726     LONG stacklow, stackhi;
 727
 728     EAX_reg(&context) = 0;
 729     if (!(pTask = (TDB *)GlobalLock( hCurrentTask ))) return;
 730     if (!(pModule = (NE_MODULE *)GlobalLock( pTask->hModule ))) return;
 731
 732     if (firstTask)
 733     {
 734         extern BOOL WIDGETS_Init(void);
 735         extern BOOL WIN_CreateDesktopWindow(void);
 736
 737         /* Perform global initialisations that need a task context */
 738
 739           /* Initialize built-in window classes */
 740         if (!WIDGETS_Init()) return;
 741
 742           /* Create desktop window */
 743         if (!WIN_CreateDesktopWindow()) return;
 744
 745         firstTask = 0;
 746     }
 747
 748 #ifndef WINELIB
 749     NE_InitializeDLLs( pTask->hModule );
 750 #endif
 751
 752     /* Registers on return are:
 753      * ax     1 if OK, 0 on error
 754      * cx     stack limit in bytes
 755      * dx     cmdShow parameter
 756      * si     instance handle of the previous instance
 757      * di     instance handle of the new task
 758      * es:bx  pointer to command-line inside PSP
 759      */
 760     EAX_reg(&context) = 1;
 761     EBX_reg(&context) = 0x81;
 762     ECX_reg(&context) = pModule->stack_size;
 763     EDX_reg(&context) = pTask->nCmdShow;
 764     ESI_reg(&context) = (DWORD)pTask->hPrevInstance;
 765     EDI_reg(&context) = (DWORD)pTask->hInstance;
 766     ES_reg (&context) = (WORD)pTask->hPDB;
 767
 768     /* Initialize the local heap */
 769     if ( pModule->heap_size )
 770     {
 771         LocalInit( pTask->hInstance, 0, pModule->heap_size );
 772     }
 773
 774
 775     /* Initialize the INSTANCEDATA structure */
 776     pSegTable = NE_SEG_TABLE( pModule );
 777     stacklow = pSegTable[pModule->ss - 1].minsize;
 778     stackhi  = stacklow + pModule->stack_size;
 779     if (stackhi > 0xffff) stackhi = 0xffff;
 780     pinstance = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN(CURRENT_DS, 0);
 781     pinstance->stackbottom = stackhi; /* yup, that's right. Confused me too. */
 782     pinstance->stacktop    = stacklow;
 783 #ifndef WINELIB /* FIXME: JBP: IF1632 not allowed in libwine.a */
 784     pinstance->stackmin    = IF1632_Saved16_sp;
 785 #endif
 786 }
 787
 788
 789 /***********************************************************************
 790  *           WaitEvent  (KERNEL.30)
 791  */
 792 BOOL WaitEvent( HTASK hTask )
 793 {
 794     TDB *pTask;
 795
 796     if (!hTask) hTask = hCurrentTask;
 797     pTask = (TDB *)GlobalLock( hTask );
 798     if (pTask->nEvents > 0)
 799     {
 800         pTask->nEvents--;
 801         return FALSE;
 802     }
 803     TASK_SCHEDULE();
 804     /* When we get back here, we have an event (or the task is the only one) */
 805     if (pTask->nEvents > 0) pTask->nEvents--;
 806     return TRUE;
 807 }
 808
 809
 810 /***********************************************************************
 811  *           PostEvent  (KERNEL.31)
 812  */
 813 void PostEvent( HTASK hTask )
 814 {
 815     TDB *pTask;
 816
 817     if (!hTask) hTask = hCurrentTask;
 818     if (!(pTask = (TDB *)GlobalLock( hTask ))) return;
 819     pTask->nEvents++;
 820 }
 821
 822
 823 /***********************************************************************
 824  *           SetPriority  (KERNEL.32)
 825  */
 826 void SetPriority( HTASK hTask, int delta )
 827 {
 828     TDB *pTask;
 829     int newpriority;
 830
 831     if (!hTask) hTask = hCurrentTask;
 832     if (!(pTask = (TDB *)GlobalLock( hTask ))) return;
 833     newpriority = pTask->priority + delta;
 834     if (newpriority < -32) newpriority = -32;
 835     else if (newpriority > 15) newpriority = 15;
 836
 837     pTask->priority = newpriority + 1;
 838     TASK_UnlinkTask( hTask );
 839     TASK_LinkTask( hTask );
 840     pTask->priority--;
 841 }
 842
 843
 844 /***********************************************************************
 845  *           LockCurrentTask  (KERNEL.33)
 846  */
 847 HTASK LockCurrentTask( BOOL bLock )
 848 {
 849     if (bLock) hLockedTask = hCurrentTask;
 850     else hLockedTask = 0;
 851     return hLockedTask;
 852 }
 853
 854
 855 /***********************************************************************
 856  *           IsTaskLocked  (KERNEL.122)
 857  */
 858 WORD IsTaskLocked(void)
 859 {
 860     return hLockedTask;
 861 }
 862
 863
 864 /***********************************************************************
 865  *           OldYield  (KERNEL.117)
 866  */
 867 void OldYield(void)
 868 {
 869     TDB *pCurTask;
 870
 871     pCurTask = (TDB *)GlobalLock( hCurrentTask );
 872     if (pCurTask) pCurTask->nEvents++;  /* Make sure we get back here */
 873     TASK_SCHEDULE();
 874     if (pCurTask) pCurTask->nEvents--;
 875 }
 876
 877
 878 /***********************************************************************
 879  *           DirectedYield  (KERNEL.150)
 880  */
 881 void DirectedYield( HTASK hTask )
 882 {
 883     TDB *pCurTask;
 884
 885     if ((pCurTask = (TDB *)GlobalLock( hCurrentTask )) != NULL)
 886         pCurTask->hYieldTo = hTask;
 887
 888     OldYield();
 889 }
 890
 891
 892 /***********************************************************************
 893  *           Yield  (KERNEL.29)
 894  */
 895 void Yield(void)
 896 {
 897     DirectedYield( 0 );
 898 }
 899
 900
 901 /***********************************************************************
 902  *           MakeProcInstance  (KERNEL.51)
 903  */
 904 FARPROC MakeProcInstance( FARPROC func, HANDLE hInstance )
 905 {
 906     BYTE *thunk;
 907     SEGPTR thunkaddr;
 908
 909     thunkaddr = TASK_AllocThunk( hCurrentTask );
 910     if (!thunkaddr) return (FARPROC)0;
 911     thunk = PTR_SEG_TO_LIN( thunkaddr );
 912
 913     dprintf_task( stddeb, "MakeProcInstance(%08lx,"NPFMT"): got thunk %08lx\n",
 914                   (SEGPTR)func, hInstance, (SEGPTR)thunkaddr );
 915
 916     *thunk++ = 0xb8;    /* movw instance, %ax */
 917 #ifndef WINELIB
 918     *thunk++ = (BYTE)(hInstance & 0xff);
 919     *thunk++ = (BYTE)(hInstance >> 8);
 920 #endif
 921     *thunk++ = 0xea;    /* ljmp func */
 922     *(DWORD *)thunk = (DWORD)func;
 923     return (FARPROC)thunkaddr;
 924 }
 925
 926
 927 /***********************************************************************
 928  *           FreeProcInstance  (KERNEL.52)
 929  */
 930 void FreeProcInstance( FARPROC func )
 931 {
 932     dprintf_task( stddeb, "FreeProcInstance(%08lx)\n", (SEGPTR)func );
 933     TASK_FreeThunk( hCurrentTask, (SEGPTR)func );
 934 }
 935
 936
 937 /**********************************************************************
 938  *          GetCodeHandle    (KERNEL.93)
 939  */
 940 HANDLE GetCodeHandle( FARPROC proc )
 941 {
 942     HANDLE handle;
 943     BYTE *thunk = (BYTE *)PTR_SEG_TO_LIN( proc );
 944
 945     /* Return the code segment containing 'proc'. */
 946     /* Not sure if this is really correct (shouldn't matter that much). */
 947
 948     /* Check if it is really a thunk */
 949     if ((thunk[0] == 0xb8) && (thunk[3] == 0xea))
 950         handle = GlobalHandle( thunk[6] + (thunk[7] << 8) );
 951     else
 952         handle = GlobalHandle( HIWORD(proc) );
 953
 954     printf( "STUB: GetCodeHandle(%08lx) returning "NPFMT"\n",
 955             (DWORD)proc, handle );
 956     return handle;
 957 }
 958
 959
 960 /***********************************************************************
 961  *           SetTaskQueue  (KERNEL.34)
 962  */
 963 HGLOBAL SetTaskQueue( HANDLE hTask, HGLOBAL hQueue )
 964 {
 965     HGLOBAL hPrev;
 966     TDB *pTask;
 967
 968     if (!hTask) hTask = hCurrentTask;
 969     if (!(pTask = (TDB *)GlobalLock( hTask ))) return 0;
 970     hPrev = pTask->hQueue;
 971     pTask->hQueue = hQueue;
 972     return hPrev;
 973 }
 974
 975
 976 /***********************************************************************
 977  *           GetTaskQueue  (KERNEL.35)
 978  */
 979 HGLOBAL GetTaskQueue( HANDLE hTask )
 980 {
 981     TDB *pTask;
 982
 983     if (!hTask) hTask = hCurrentTask;
 984     if (!(pTask = (TDB *)GlobalLock( hTask ))) return 0;
 985     return pTask->hQueue;
 986 }
 987
 988
 989 /***********************************************************************
 990  *           GetTaskQueueDS  (KERNEL.118)
 991  */
 992 #ifndef WINELIB
 993 void GetTaskQueueDS( struct sigcontext_struct context )
 994 {
 995     DS_reg(&context) = GlobalHandleToSel( GetTaskQueue(0) );
 996 }
 997 #endif  /* WINELIB */
 998
 999
1000 /***********************************************************************
1001  *           GetTaskQueueES  (KERNEL.119)
1002  */
1003 #ifndef WINELIB
1004 void GetTaskQueueES( struct sigcontext_struct context )
1005 {
1006     ES_reg(&context) = GlobalHandleToSel( GetTaskQueue(0) );
1007 }
1008 #endif  /* WINELIB */
1009
1010
1011 /***********************************************************************
1012  *           GetCurrentTask   (KERNEL.36)
1013  */
1014 HTASK GetCurrentTask(void)
1015 {
1016       /* Undocumented: first task is returned in high word */
1017 #ifdef WINELIB32
1018     return hCurrentTask;
1019 #else
1020     return MAKELONG( hCurrentTask, hFirstTask );
1021 #endif
1022 }
1023
1024
1025 /***********************************************************************
1026  *           GetCurrentPDB   (KERNEL.37)
1027  */
1028 HANDLE GetCurrentPDB(void)
1029 {
1030     TDB *pTask;
1031
1032     if (!(pTask = (TDB *)GlobalLock( hCurrentTask ))) return 0;
1033     return pTask->hPDB;
1034 }
1035
1036
1037 /***********************************************************************
1038  *           GetInstanceData   (KERNEL.54)
1039  */
1040 int GetInstanceData( HANDLE instance, WORD buffer, int len )
1041 {
1042     char *ptr = (char *)GlobalLock( instance );
1043     if (!ptr || !len) return 0;
1044     if ((int)buffer + len >= 0x10000) len = 0x10000 - buffer;
1045     memcpy( ptr + buffer, (char *)GlobalLock( CURRENT_DS ) + buffer, len );
1046     return len;
1047 }
1048
1049
1050 /***********************************************************************
1051  *           GetDOSEnvironment   (KERNEL.131)
1052  */
1053 SEGPTR GetDOSEnvironment(void)
1054 {
1055     TDB *pTask;
1056
1057     if (!(pTask = (TDB *)GlobalLock( hCurrentTask ))) return 0;
1058     return (SEGPTR)WIN16_GlobalLock( pTask->pdb.environment );
1059 }
1060
1061
1062 /***********************************************************************
1063  *           GetNumTasks   (KERNEL.152)
1064  */
1065 WORD GetNumTasks(void)
1066 {
1067     return nTaskCount;
1068 }
1069
1070
1071 /***********************************************************************
1072  *           GetTaskDS   (KERNEL.155)
1073  */
1074 HINSTANCE GetTaskDS(void)
1075 {
1076     TDB *pTask;
1077
1078     if (!(pTask = (TDB *)GlobalLock( hCurrentTask ))) return 0;
1079     return pTask->hInstance;
1080 }
1081
1082
1083 /***********************************************************************
1084  *           IsTask   (KERNEL.320)
1085  */
1086 BOOL IsTask( HTASK hTask )
1087 {
1088     TDB *pTask;
1089
1090     if (!(pTask = (TDB *)GlobalLock( hTask ))) return FALSE;
1091     if (GlobalSize( hTask ) < sizeof(TDB)) return FALSE;
1092     return (pTask->magic == TDB_MAGIC);
1093 }
1094
1095
1096 /***********************************************************************
1097  *           GetExePtr   (KERNEL.133)
1098  */
1099 HMODULE GetExePtr( HANDLE handle )
1100 {
1101     char *ptr;
1102     HTASK hTask;
1103     HANDLE owner;
1104
1105       /* Check for module handle */
1106
1107     if (!(ptr = GlobalLock( handle ))) return 0;
1108     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return handle;
1109
1110       /* Check the owner for module handle */
1111
1112 #ifndef WINELIB
1113     owner = FarGetOwner( handle );
1114 #else
1115     owner = NULL;
1116     fprintf(stderr,"JBP: FarGetOwner() ignored.\n");
1117 #endif
1118     if (!(ptr = GlobalLock( owner ))) return 0;
1119     if (((NE_MODULE *)ptr)->magic == NE_SIGNATURE) return owner;
1120
1121       /* Search for this handle and its owner inside all tasks */
1122
1123     hTask = hFirstTask;
1124     while (hTask)
1125     {
1126         TDB *pTask = (TDB *)GlobalLock( hTask );
1127         if ((hTask == handle) ||
1128             (pTask->hInstance == handle) ||
1129             (pTask->hQueue == handle) ||
1130             (pTask->hPDB == handle)) return pTask->hModule;
1131         if ((hTask == owner) ||
1132             (pTask->hInstance == owner) ||
1133             (pTask->hQueue == owner) ||
1134             (pTask->hPDB == owner)) return pTask->hModule;
1135         hTask = pTask->hNext;
1136     }
1137     return 0;
1138 }
1139
1140
1141 /***********************************************************************
1142  *           TaskFirst   (TOOLHELP.63)
1143  */
1144 BOOL TaskFirst( TASKENTRY *lpte )
1145 {
1146     lpte->hNext = hFirstTask;
1147     return TaskNext( lpte );
1148 }
1149
1150
1151 /***********************************************************************
1152  *           TaskNext   (TOOLHELP.64)
1153  */
1154 BOOL TaskNext( TASKENTRY *lpte )
1155 {
1156     TDB *pTask;
1157     INSTANCEDATA *pInstData;
1158
1159     dprintf_toolhelp( stddeb, "TaskNext(%p): task="NPFMT"\n", lpte, lpte->hNext );
1160     if (!lpte->hNext) return FALSE;
1161     pTask = (TDB *)GlobalLock( lpte->hNext );
1162     if (!pTask || pTask->magic != TDB_MAGIC) return FALSE;
1163     pInstData = (INSTANCEDATA *)PTR_SEG_OFF_TO_LIN( pTask->hInstance, 0 );
1164     lpte->hTask         = lpte->hNext;
1165     lpte->hTaskParent   = pTask->hParent;
1166     lpte->hInst         = pTask->hInstance;
1167     lpte->hModule       = pTask->hModule;
1168     lpte->wSS           = pTask->ss;
1169     lpte->wSP           = pTask->sp;
1170     lpte->wStackTop     = pInstData->stacktop;
1171     lpte->wStackMinimum = pInstData->stackmin;
1172     lpte->wStackBottom  = pInstData->stackbottom;
1173     lpte->wcEvents      = pTask->nEvents;
1174     lpte->hQueue        = pTask->hQueue;
1175     strncpy( lpte->szModule, pTask->module_name, 8 );
1176     lpte->szModule[8]   = '\0';
1177     lpte->wPSPOffset    = 0x100;  /*??*/
1178     lpte->hNext         = pTask->hNext;
1179     return TRUE;
1180 }
1181
1182
1183 /***********************************************************************
1184  *           TaskFindHandle   (TOOLHELP.65)
1185  */
1186 BOOL TaskFindHandle( TASKENTRY *lpte, HTASK hTask )
1187 {
1188     lpte->hNext = hTask;
1189     return TaskNext( lpte );
1190 }