KernelLand/Kernel/threads.c

   1 /*
   2  * Acess2 Kernel
   3  * - By John Hodge (thePowersGang)
   4  * threads.c
   5  * - Common Thread Control
   6  */
   7 #define DEBUG   0
   8 #include <acess.h>
   9 #include <threads.h>
  10 #include <threads_int.h>
  11 #include <errno.h>
  12 #include <hal_proc.h>
  13 #include <semaphore.h>
  14 #include <rwlock.h>
  15 #include <vfs_threads.h>        // VFS Handle maintainence
  16 #include <events.h>
  17 #include <debug_hooks.h>
  18
  19 // Configuration
  20 #define DEBUG_TRACE_ACTIVEQUEUE 0       // Trace adds/removals from the active queue
  21 #define DEBUG_TRACE_TICKETS     0       // Trace ticket counts
  22 #define DEBUG_TRACE_STATE       0       // Trace state changes (sleep/wake)
  23 #define DEBUG_TRACE_SCHEDULE    0       // Trace scheduling
  24
  25 // --- Schedulers ---
  26 #define SCHED_UNDEF     0
  27 #define SCHED_LOTTERY   1       // Lottery scheduler
  28 #define SCHED_RR_SIM    2       // Single Queue Round Robin
  29 #define SCHED_RR_PRI    3       // Multi Queue Round Robin
  30 // Set scheduler type
  31 #define SCHEDULER_TYPE  SCHED_RR_PRI
  32
  33 // === CONSTANTS ===
  34 #define DEFAULT_QUANTUM 5
  35 #define DEFAULT_PRIORITY        5
  36 #define MIN_PRIORITY            10
  37
  38 #define PRIthread_fmt   "%p(%i %s)"
  39 #define PRIthread_args(t)       (t), ((t)?(t)->TID:-1), ((t)?(t)->ThreadName:"-")
  40
  41 // === IMPORTS ===
  42 extern void     User_Signal_Kill(int SigNum);
  43
  44 // === TYPE ===
  45 typedef struct
  46 {
  47         tThread *Head;
  48         tThread *Tail;
  49 } tThreadList;
  50
  51 // === PROTOTYPES ===
  52 void    Threads_Init(void);
  53 #if 0
  54 void    Threads_Delete(tThread *Thread);
  55  int    Threads_SetName(const char *NewName);
  56 #endif
  57 char    *Threads_GetName(tTID ID);
  58 #if 0
  59 void    Threads_SetPriority(tThread *Thread, int Pri);
  60 tThread *Threads_CloneTCB(Uint Flags);
  61  int    Threads_WaitTID(int TID, int *status);
  62 tThread *Threads_GetThread(Uint TID);
  63 #endif
  64 tThread *Threads_int_DelFromQueue(tThreadList *List, tThread *Thread);
  65 void    Threads_int_AddToList(tThreadList *List, tThread *Thread);
  66 #if 0
  67 void    Threads_Exit(int TID, int Status);
  68 void    Threads_Kill(tThread *Thread, int Status);
  69 void    Threads_Yield(void);
  70  int    Threads_int_Sleep(enum eThreadStatus Status, void *Ptr, int Num, tThread **ListHead, tThread **ListTail, tShortSpinlock *Lock);
  71 void    Threads_Sleep(void);
  72  int    Threads_Wake(tThread *Thread);
  73 void    Threads_AddActive(tThread *Thread);
  74 tThread *Threads_RemActive(void);
  75 void    Threads_ToggleTrace(int TID);
  76 #endif
  77 void    Threads_Fault(int Num);
  78 void    Threads_SegFault(tVAddr Addr);
  79 void    Threads_PostSignalTo(tThread *Thread, int SignalNum);
  80 #if 0
  81 void    Threads_PostSignal(int SignalNum);
  82 void    Threads_SignalGroup(tPGID PGID, int SignalNum);
  83 #endif
  84  int    Threads_GetPendingSignal(void);
  85 void    Threads_SetSignalHandler(int SignalNum, void *Handler);
  86 void    *Threads_GetSignalHandler(int SignalNum);
  87 #if 0
  88  int    Threads_GetPID(void);
  89  int    Threads_GetTID(void);
  90 tUID    Threads_GetUID(void);
  91 tGID    Threads_GetGID(void);
  92  int    Threads_SetUID(Uint *Errno, tUID ID);
  93  int    Threads_SetGID(Uint *Errno, tUID ID);
  94 #endif
  95 void    Threads_int_DumpThread(tThread *thread);
  96 #if 0
  97 void    Threads_Dump(void);
  98 #endif
  99 void    Threads_DumpActive(void);
 100 tThread *Threads_int_GetRunnable(void);
 101
 102 // === GLOBALS ===
 103 // -- Core Thread --
 104 tProcess        gProcessZero = {
 105         };
 106 // Only used for the core kernel
 107 tThread gThreadZero = {
 108         .Status         = THREAD_STAT_ACTIVE,   // Status
 109         .ThreadName     = (char*)"ThreadZero",  // Name
 110         .Quantum        = DEFAULT_QUANTUM,      // Default Quantum
 111         .Remaining      = DEFAULT_QUANTUM,      // Current Quantum
 112         .Priority       = DEFAULT_PRIORITY      // Number of tickets
 113         };
 114 // -- Processes --
 115 tProcess        *gAllProcesses = &gProcessZero;
 116 // --- Locks ---
 117 tShortSpinlock  glThreadListLock;       ///\note NEVER use a heap function while locked
 118 // --- Current State ---
 119 volatile int    giNumActiveThreads = 0; // Number of threads on the active queue
 120 volatile Uint   giNextTID = 1;  // Next TID to allocate
 121 // --- Thread Lists ---
 122 tThread *gAllThreads = NULL;            // All allocated threads
 123 tThreadList     gSleepingThreads;       // Sleeping Threads
 124  int    giNumCPUs = 1;  // Number of CPUs
 125 BOOL     gaThreads_NoTaskSwitch[MAX_CPUS];      // Disables task switches for each core (Pseudo-IF)
 126 // --- Scheduler Types ---
 127 #if SCHEDULER_TYPE == SCHED_LOTTERY
 128 const int       caiTICKET_COUNTS[MIN_PRIORITY+1] = {100,81,64,49,36,25,16,9,4,1,0};
 129 volatile int    giFreeTickets = 0;      // Number of tickets held by non-scheduled threads
 130 tThreadList     gActiveThreads;         // Currently Running Threads
 131 #elif SCHEDULER_TYPE == SCHED_RR_SIM
 132 tThreadList     gActiveThreads;         // Currently Running Threads
 133 #elif SCHEDULER_TYPE == SCHED_RR_PRI
 134 tThreadList     gaActiveThreads[MIN_PRIORITY+1];        // Active threads for each priority level
 135 #else
 136 # error "Unkown scheduler type"
 137 #endif
 138
 139 // === CODE ===
 140 /**
 141  * \fn void Threads_Init(void)
 142  * \brief Initialse the thread list
 143  */
 144 void Threads_Init(void)
 145 {
 146         ArchThreads_Init();
 147
 148         Log_Debug("Threads", "Offsets of tThread");
 149         Log_Debug("Threads", ".Priority = %i", offsetof(tThread, Priority));
 150         Log_Debug("Threads", ".KernelStack = %i", offsetof(tThread, KernelStack));
 151
 152         // Create Initial Task
 153         gAllThreads = &gThreadZero;
 154         giNumActiveThreads = 1;
 155         gThreadZero.Process = &gProcessZero;
 156
 157         Proc_Start();
 158 }
 159
 160 void Threads_Delete(tThread *Thread)
 161 {
 162         // Set to dead
 163         Thread->Status = THREAD_STAT_BURIED;
 164
 165         // Clear out process state
 166         Proc_ClearThread(Thread);
 167
 168         Thread->Process->nThreads --;
 169
 170         if( Thread->Process->FirstThread == Thread )
 171         {
 172                 Thread->Process->FirstThread = Thread->ProcessNext;
 173         }
 174         else
 175         {
 176                 tThread *prev = Thread->Process->FirstThread;
 177                 while(prev && prev->ProcessNext != Thread)
 178                         prev = prev->ProcessNext;
 179                 if( !prev )
 180                         Log_Error("Threads", "Thread %p(%i %s) is not on the process's list",
 181                                 Thread, Thread->TID, Thread->ThreadName
 182                                 );
 183                 else
 184                         prev->ProcessNext = Thread->ProcessNext;
 185         }
 186
 187         // If the final thread is being terminated, clean up the process
 188         if( Thread->Process->nThreads == 0 )
 189         {
 190                 tProcess        *proc = Thread->Process;
 191
 192                 // Remove from global process list
 193                 // TODO: RWLock
 194                 if(proc->Prev)
 195                         proc->Prev->Next = proc->Next;
 196                 else
 197                         gAllProcesses = proc->Next;
 198                 if(proc->Next)
 199                         proc->Next->Prev = proc->Prev;
 200
 201                 // VFS Cleanup
 202                 VFS_CloseAllUserHandles( proc );
 203                 // Architecture cleanup
 204                 Proc_ClearProcess( proc );
 205                 // VFS Configuration strings
 206                 if( proc->CurrentWorkingDir)
 207                         free( proc->CurrentWorkingDir );
 208                 if( proc->RootDir )
 209                         free( proc->RootDir );
 210                 // Process descriptor
 211                 free( proc );
 212         }
 213
 214         // Free name
 215         if( IsHeap(Thread->ThreadName) )
 216                 free(Thread->ThreadName);
 217
 218         // Remove from global list
 219         // TODO: Lock this too
 220         if( Thread == gAllThreads )
 221                 gAllThreads = Thread->GlobalNext;
 222         else
 223                 Thread->GlobalPrev->GlobalNext = Thread->GlobalNext;
 224
 225         free(Thread);
 226 }
 227
 228 /**
 229  * \fn void Threads_SetName(const char *NewName)
 230  * \brief Sets the current thread's name
 231  * \param NewName       New name for the thread
 232  * \return Boolean Failure
 233  */
 234 int Threads_SetName(const char *NewName)
 235 {
 236         tThread *cur = Proc_GetCurThread();
 237         char    *oldname = cur->ThreadName;
 238
 239         // NOTE: There is a possibility of non-thread safety here
 240         // A thread could read the current name pointer before it is zeroed
 241
 242         cur->ThreadName = NULL;
 243
 244         if( IsHeap(oldname) )   free( oldname );
 245         cur->ThreadName = strdup(NewName);
 246
 247         Log_Debug("Threads", "Thread renamed to '%s'", NewName);
 248
 249         return 0;
 250 }
 251
 252 /**
 253  * \fn char *Threads_GetName(int ID)
 254  * \brief Gets a thread's name
 255  * \param ID    Thread ID (-1 indicates current thread)
 256  * \return Pointer to name
 257  * \retval NULL Failure
 258  */
 259 char *Threads_GetName(tTID ID)
 260 {
 261         if(ID == -1) {
 262                 return Proc_GetCurThread()->ThreadName;
 263         }
 264         return Threads_GetThread(ID)->ThreadName;
 265 }
 266
 267 /**
 268  * \fn void Threads_SetPriority(tThread *Thread, int Pri)
 269  * \brief Sets the priority of a task
 270  * \param Thread        Thread to update ticket count (NULL means current thread)
 271  * \param Pri   New priority
 272  */
 273 void Threads_SetPriority(tThread *Thread, int Pri)
 274 {
 275         // Get current thread
 276         if(Thread == NULL)      Thread = Proc_GetCurThread();
 277         // Bounds checking
 278         // - If < 0, set to lowest priority
 279         // - Minumum priority is actualy a high number, 0 is highest
 280         if(Pri < 0)     Pri = MIN_PRIORITY;
 281         if(Pri > MIN_PRIORITY)  Pri = MIN_PRIORITY;
 282
 283         // Do we actually have to do anything?
 284         if( Pri == Thread->Priority )   return;
 285
 286         #if SCHEDULER_TYPE == SCHED_RR_PRI
 287         if( Thread != Proc_GetCurThread() )
 288         {
 289                 SHORTLOCK( &glThreadListLock );
 290                 // Remove from old priority
 291                 Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread );
 292                 // And add to new
 293                 Threads_int_AddToList( &gaActiveThreads[Pri], Thread );
 294                 Thread->Priority = Pri;
 295                 SHORTREL( &glThreadListLock );
 296         }
 297         else
 298                 Thread->Priority = Pri;
 299         #else
 300         // If this isn't the current thread, we need to lock
 301         if( Thread != Proc_GetCurThread() )
 302         {
 303                 SHORTLOCK( &glThreadListLock );
 304
 305                 #if SCHEDULER_TYPE == SCHED_LOTTERY
 306                 giFreeTickets -= caiTICKET_COUNTS[Thread->Priority] - caiTICKET_COUNTS[Pri];
 307                 # if DEBUG_TRACE_TICKETS
 308                 Log("Threads_SetTickets: new giFreeTickets = %i [-%i+%i]",
 309                         giFreeTickets,
 310                         caiTICKET_COUNTS[Thread->Priority], caiTICKET_COUNTS[Pri]);
 311                 # endif
 312                 #endif
 313                 Thread->Priority = Pri;
 314                 SHORTREL( &glThreadListLock );
 315         }
 316         else
 317                 Thread->Priority = Pri;
 318         #endif
 319
 320         #if DEBUG_TRACE_STATE
 321         Log("Threads_SetPriority: %p(%i %s) pri set %i",
 322                 Thread, Thread->TID, Thread->ThreadName,
 323                 Pri);
 324         #endif
 325 }
 326
 327 /**
 328  * \brief Clone the TCB of the current thread
 329  * \param Flags Flags for something... (What is this for?)
 330  */
 331 tThread *Threads_CloneTCB(Uint Flags)
 332 {
 333         tThread *cur = Proc_GetCurThread();
 334
 335         // Allocate and duplicate
 336         tThread *new = malloc(sizeof(tThread));
 337         if(new == NULL) { errno = -ENOMEM; return NULL; }
 338         memcpy(new, cur, sizeof(tThread));
 339
 340         new->CurCPU = -1;
 341         new->Next = NULL;
 342         memset( &new->IsLocked, 0, sizeof(new->IsLocked));
 343         new->Status = THREAD_STAT_PREINIT;
 344         new->RetStatus = 0;
 345
 346         // Get Thread ID
 347         new->TID = giNextTID++;
 348         new->Parent = cur;
 349         new->bInstrTrace = 0;
 350
 351         // Clone Name
 352         new->ThreadName = strdup(cur->ThreadName);
 353
 354         // Set Thread Group ID (PID)
 355         if(Flags & CLONE_VM) {
 356                 tProcess        *newproc, *oldproc;
 357                 oldproc = cur->Process;
 358                 new->Process = calloc( sizeof(struct sProcess), 1 );
 359                 newproc = new->Process;
 360                 newproc->PID = new->TID;
 361                 if( Flags & CLONE_PGID )
 362                         newproc->PGID = oldproc->PGID;
 363                 else
 364                         newproc->PGID = newproc->PID;
 365                 newproc->UID = oldproc->UID;
 366                 newproc->GID = oldproc->GID;
 367                 newproc->MaxFD = oldproc->MaxFD;
 368                 newproc->CurrentWorkingDir = oldproc->CurrentWorkingDir ? strdup( oldproc->CurrentWorkingDir ) : NULL;
 369                 newproc->RootDir = oldproc->RootDir ? strdup( oldproc->RootDir ) : NULL;
 370                 newproc->nThreads = 1;
 371                 // Reference all handles in the VFS
 372                 VFS_ReferenceUserHandles();
 373
 374                 // Add to global list
 375                 newproc->Prev = NULL;
 376                 // TODO: RWLock
 377                 newproc->Next = gAllProcesses;
 378                 gAllProcesses = newproc;
 379
 380                 newproc->FirstThread = new;
 381                 new->ProcessNext = NULL;
 382         }
 383         else {
 384                 new->Process->nThreads ++;
 385                 new->Process = cur->Process;
 386                 // TODO: Locking
 387                 new->ProcessNext = new->Process->FirstThread;
 388                 new->Process->FirstThread = new;
 389         }
 390
 391         // Messages are not inherited
 392         new->Messages = NULL;
 393         new->LastMessage = NULL;
 394
 395         // Set State
 396         new->Remaining = new->Quantum = cur->Quantum;
 397         new->Priority = cur->Priority;
 398         new->_errno = 0;
 399
 400         // Set Signal Handlers
 401         new->CurFaultNum = 0;
 402         new->FaultHandler = cur->FaultHandler;
 403
 404         // Maintain a global list of threads
 405         SHORTLOCK( &glThreadListLock );
 406         new->GlobalPrev = NULL; // Protect against bugs
 407         new->GlobalNext = gAllThreads;
 408         gAllThreads->GlobalPrev = new;
 409         gAllThreads = new;
 410         SHORTREL( &glThreadListLock );
 411
 412         return new;
 413 }
 414
 415 /**
 416  * \brief Clone the TCB of the kernel thread
 417  */
 418 tThread *Threads_CloneThreadZero(void)
 419 {
 420         tThread *new;
 421
 422         // Allocate and duplicate
 423         new = malloc(sizeof(tThread));
 424         if(new == NULL) {
 425                 return NULL;
 426         }
 427         memcpy(new, &gThreadZero, sizeof(tThread));
 428
 429         new->Process->nThreads ++;
 430
 431         new->CurCPU = -1;
 432         new->Next = NULL;
 433         memset( &new->IsLocked, 0, sizeof(new->IsLocked));
 434         new->Status = THREAD_STAT_PREINIT;
 435         new->RetStatus = 0;
 436
 437         // Get Thread ID
 438         new->TID = giNextTID++;
 439         new->Parent = 0;
 440
 441         // Clone Name
 442         new->ThreadName = NULL;
 443
 444         // Messages are not inherited
 445         new->Messages = NULL;
 446         new->LastMessage = NULL;
 447
 448         // Set State
 449         new->Remaining = new->Quantum = DEFAULT_QUANTUM;
 450         new->Priority = DEFAULT_PRIORITY;
 451         new->bInstrTrace = 0;
 452
 453         // Set Signal Handlers
 454         new->CurFaultNum = 0;
 455         new->FaultHandler = 0;
 456
 457         // Maintain a global list of threads
 458         SHORTLOCK( &glThreadListLock );
 459         new->GlobalPrev = NULL; // Protect against bugs
 460         new->GlobalNext = gAllThreads;
 461         gAllThreads->GlobalPrev = new;
 462         gAllThreads = new;
 463         SHORTREL( &glThreadListLock );
 464
 465         return new;
 466 }
 467
 468 /**
 469  * \brief Wait for a task to change state
 470  * \param TID   Thread ID to wait on (-1: Any child thread, 0: Any Child/Sibling, <-1: -PID)
 471  * \param Status        Thread return status
 472  * \return TID of child that changed state
 473  */
 474 tTID Threads_WaitTID(int TID, int *Status)
 475 {
 476         // Any Child
 477         if(TID == -1)
 478         {
 479                 Uint32 ev = Threads_WaitEvents(THREAD_EVENT_DEADCHILD);
 480                 tTID    ret = -1;
 481                 if( ev & THREAD_EVENT_DEADCHILD )
 482                 {
 483                         tThread * const us = Proc_GetCurThread();
 484                         // A child died, get the TID
 485                         ASSERT(us->LastDeadChild);
 486                         tThread *dead_thread = us->LastDeadChild;
 487                         us->LastDeadChild = dead_thread->Next;
 488                         if( us->LastDeadChild )
 489                                 Threads_PostEvent( us, THREAD_EVENT_DEADCHILD );
 490                         else
 491                                 Threads_ClearEvent( THREAD_EVENT_DEADCHILD );
 492                         Mutex_Release(&us->DeadChildLock);
 493
 494                         ret = dead_thread->TID;
 495                         // - Mark as dead (as opposed to undead)
 496                         if( dead_thread->Status != THREAD_STAT_ZOMBIE ) {
 497                                 Log_Error("Thread", "Thread %p(%i %s) is not ZOMBIE, instead %s",
 498                                         dead_thread, dead_thread->TID, dead_thread->ThreadName,
 499                                         (dead_thread->Status < ciTHREAD_STAT_COUNT ? casTHREAD_STAT[dead_thread->Status] : "?")
 500                                         );
 501                                 ASSERTC(dead_thread->Status, ==, THREAD_STAT_ZOMBIE);
 502                         }
 503                         dead_thread->Status = THREAD_STAT_DEAD;
 504                         // - Set return status
 505                         if(Status)
 506                                 *Status = dead_thread->RetStatus;
 507
 508                         Threads_Delete( dead_thread );
 509                 }
 510                 else
 511                 {
 512                         Log_Error("Threads", "TODO: Threads_WaitTID(TID=-1) - Woken with no child");
 513                 }
 514                 return ret;
 515         }
 516
 517         // Any peer/child thread
 518         if(TID == 0) {
 519                 Log_Error("Threads", "TODO: Threads_WaitTID(TID=0) - Any Child/Sibling");
 520                 return -1;
 521         }
 522
 523         // TGID = abs(TID)
 524         if(TID < -1) {
 525                 Log_Error("Threads", "TODO: Threads_WaitTID(TID<0) - TGID");
 526                 return -1;
 527         }
 528
 529         // Specific Thread
 530         if(TID > 0)
 531         {
 532                 // TODO: Register on thread to be poked when it dies
 533                 tTID    ret;
 534                 // NOTE: Race condition - Other child dies, desired child dies, first death is 'lost'
 535                 while( (ret = Threads_WaitTID(-1, Status)) != TID )
 536                 {
 537                         if( ret == -1 )
 538                                 break;
 539                 }
 540                 return ret;
 541         }
 542
 543         return -1;
 544 }
 545
 546 /**
 547  * \brief Gets a thread given its TID
 548  * \param TID   Thread ID
 549  * \return Thread pointer
 550  */
 551 tThread *Threads_GetThread(Uint TID)
 552 {
 553         tThread *thread;
 554
 555         // Search global list
 556         for( thread = gAllThreads; thread; thread = thread->GlobalNext )
 557         {
 558                 if(thread->TID == TID)
 559                         return thread;
 560         }
 561
 562         Log_Notice("Threads", "Unable to find TID %i on main list\n", TID);
 563
 564         return NULL;
 565 }
 566
 567 /**
 568  * \brief Deletes an entry from a list
 569  * \param List  Pointer to the list head
 570  * \param Thread        Thread to find
 571  * \return \a Thread
 572  */
 573 tThread *Threads_int_DelFromQueue(tThreadList *List, tThread *Thread)
 574 {
 575         tThread *ret, *prev = NULL;
 576
 577         for(ret = List->Head;
 578                 ret && ret != Thread;
 579                 prev = ret, ret = ret->Next
 580                 );
 581
 582         // Is the thread on the list
 583         if(!ret) {
 584                 //LogF("%p(%s) is not on list %p\n", Thread, Thread->ThreadName, List);
 585                 return NULL;
 586         }
 587
 588         if( !prev ) {
 589                 List->Head = Thread->Next;
 590                 //LogF("%p(%s) removed from head of %p\n", Thread, Thread->ThreadName, List);
 591         }
 592         else {
 593                 prev->Next = Thread->Next;
 594                 //LogF("%p(%s) removed from %p (prev=%p)\n", Thread, Thread->ThreadName, List, prev);
 595         }
 596         if( Thread->Next == NULL )
 597                 List->Tail = prev;
 598
 599         return Thread;
 600 }
 601
 602 void Threads_int_AddToList(tThreadList *List, tThread *Thread)
 603 {
 604         if( List->Head )
 605                 List->Tail->Next = Thread;
 606         else
 607                 List->Head = Thread;
 608         List->Tail = Thread;
 609         Thread->Next = NULL;
 610 }
 611
 612 /**
 613  * \brief Exit the current process (or another?)
 614  * \param TID   Thread ID to kill
 615  * \param Status        Exit status
 616  */
 617 void Threads_Exit(int TID, int Status)
 618 {
 619         if( TID == 0 )
 620                 Threads_Kill( Proc_GetCurThread(), (Uint)Status & 0xFF );
 621         else
 622                 Threads_Kill( Threads_GetThread(TID), (Uint)Status & 0xFF );
 623
 624         // Halt forever, just in case
 625         for(;;) HALT();
 626 }
 627
 628 /**
 629  * \fn void Threads_Kill(tThread *Thread, int Status)
 630  * \brief Kill a thread
 631  * \param Thread        Thread to kill
 632  * \param Status        Status code to return to the parent
 633  */
 634 void Threads_Kill(tThread *Thread, int Status)
 635 {
 636          int    isCurThread = Thread == Proc_GetCurThread();
 637
 638         // TODO: Disown all children?
 639         #if 1
 640         {
 641                 // TODO: I should keep a .Children list
 642                 for(tThread* child = gAllThreads; child; child = child->GlobalNext)
 643                 {
 644                         if(child->Parent == Thread)
 645                                 child->Parent = &gThreadZero;
 646                 }
 647         }
 648         #endif
 649
 650         ///\note Double lock is needed due to overlap of lock areas
 651
 652         // Lock thread (stop us recieving messages)
 653         SHORTLOCK( &Thread->IsLocked );
 654
 655         // Clear Message Queue
 656         while( Thread->Messages )
 657         {
 658                 tMsg    *msg = Thread->Messages->Next;
 659                 free( Thread->Messages );
 660                 Thread->Messages = msg;
 661         }
 662
 663         // Lock thread list
 664         SHORTLOCK( &glThreadListLock );
 665
 666         switch(Thread->Status)
 667         {
 668         case THREAD_STAT_PREINIT:       // Only on main list
 669                 break;
 670
 671         // Currently active thread
 672         case THREAD_STAT_ACTIVE:
 673                 if( Thread != Proc_GetCurThread() )
 674                 {
 675                         #if SCHEDULER_TYPE == SCHED_RR_PRI
 676                         tThreadList     *list = &gaActiveThreads[Thread->Priority];
 677                         #else
 678                         tThreadList     *list = &gActiveThreads;
 679                         #endif
 680                         if( Threads_int_DelFromQueue( list, Thread ) )
 681                         {
 682                         }
 683                         else
 684                         {
 685                                 Log_Warning("Threads",
 686                                         "Threads_Kill - Thread %p(%i,%s) marked as active, but not on list",
 687                                         Thread, Thread->TID, Thread->ThreadName
 688                                         );
 689                         }
 690                         #if SCHEDULER_TYPE == SCHED_LOTTERY
 691                         giFreeTickets -= caiTICKET_COUNTS[ Thread->Priority ];
 692                         #endif
 693                 }
 694                 // Ensure that we are not rescheduled
 695                 Thread->Remaining = 0;  // Clear Remaining Quantum
 696                 Thread->Quantum = 0;    // Clear Quantum to indicate dead thread
 697
 698                 // Update bookkeeping
 699                 giNumActiveThreads --;
 700                 break;
 701         // Kill it while it sleeps!
 702         case THREAD_STAT_SLEEPING:
 703                 if( !Threads_int_DelFromQueue( &gSleepingThreads, Thread ) )
 704                 {
 705                         Log_Warning("Threads",
 706                                 "Threads_Kill - Thread "PRIthread_fmt" marked as sleeping, but not on list",
 707                                 PRIthread_args(Thread)
 708                                 );
 709                 }
 710                 break;
 711
 712         // Brains!... You cannot kill something that is already dead
 713         case THREAD_STAT_ZOMBIE:
 714                 Log_Warning("Threads", "Threads_Kill - Thread %p(%i,%s) is undead, you cannot kill it",
 715                         Thread, Thread->TID, Thread->ThreadName);
 716                 SHORTREL( &glThreadListLock );
 717                 SHORTREL( &Thread->IsLocked );
 718                 return ;
 719
 720         default:
 721                 Log_Warning("Threads", "Threads_Kill - BUG Un-checked status (%i)",
 722                         Thread->Status);
 723                 break;
 724         }
 725
 726         // Save exit status
 727         Thread->RetStatus = Status;
 728
 729         Thread->Status = THREAD_STAT_ZOMBIE;
 730         SHORTREL( &glThreadListLock );
 731         // TODO: It's possible that we could be timer-preempted here, should disable that... somehow
 732         Mutex_Acquire( &Thread->Parent->DeadChildLock );        // released by parent
 733         Thread->Next = Thread->Parent->LastDeadChild;
 734         Thread->Parent->LastDeadChild = Thread;
 735         Threads_PostEvent( Thread->Parent, THREAD_EVENT_DEADCHILD );
 736
 737         // Process cleanup happens on reaping
 738         Log("Thread "PRIthread_fmt" went *hurk* (%i) (isCurThread=%B)", PRIthread_args(Thread), Status, isCurThread);
 739         //Log("Thread status = %i %s", Thread->Status, casTHREAD_STAT[Thread->Status]);
 740
 741         SHORTREL( &Thread->IsLocked );
 742
 743         // And, reschedule
 744         if(isCurThread)
 745         {
 746                 for( ;; )
 747                         Proc_Reschedule();
 748         }
 749 }
 750
 751 /**
 752  * \brief Yield remainder of the current thread's timeslice
 753  */
 754 void Threads_Yield(void)
 755 {
 756 //      Log("Threads_Yield: by %p", __builtin_return_address(0));
 757         Proc_Reschedule();
 758 }
 759
 760 /**
 761  * \breif Wait for the thread status to not be a specified value
 762  */
 763 void Threads_int_WaitForStatusEnd(enum eThreadStatus Status)
 764 {
 765         tThread *us = Proc_GetCurThread();
 766         LOG("us = %p(%i %s), status=%i", us, us->TID, us->ThreadName, Status);
 767         ASSERT(Status != THREAD_STAT_ACTIVE);
 768         ASSERT(Status != THREAD_STAT_DEAD);
 769         while( us->Status == Status )
 770         {
 771                 Proc_Reschedule();
 772                 if( us->Status == Status )
 773                         Debug("Thread %p(%i %s) rescheduled while in %s state for %p",
 774                                 us, us->TID, us->ThreadName,
 775                                 casTHREAD_STAT[Status],
 776                                 __builtin_return_address(0));
 777         }
 778 }
 779
 780 int Threads_int_Sleep(enum eThreadStatus Status, void *Ptr, int Num, tThread **ListHead, tThread **ListTail, tShortSpinlock *Lock)
 781 {
 782         SHORTLOCK( &glThreadListLock );
 783         tThread *us = Threads_RemActive();
 784         us->Next = NULL;
 785         // - Mark as sleeping
 786         us->Status = Status;
 787         us->WaitPointer = Ptr;
 788         us->RetStatus = Num;    // Use RetStatus as a temp variable
 789
 790         // - Add to waiting
 791         if( ListTail ) {
 792                 if(*ListTail) {
 793                         (*ListTail)->Next = us;
 794                 }
 795                 else {
 796                         *ListHead = us;
 797                 }
 798                 *ListTail = us;
 799         }
 800         else if( ListHead ) {
 801                 us->Next = *ListHead;
 802                 *ListHead = us;
 803         }
 804         else {
 805                 // Nothing
 806         }
 807
 808         //if( Proc_ThreadSync(us) )
 809         //      return ;
 810         SHORTREL( &glThreadListLock );
 811         if( Lock )
 812                 SHORTREL( Lock );
 813         Threads_int_WaitForStatusEnd(Status);
 814         us->WaitPointer = NULL;
 815         return us->RetStatus;
 816 }
 817
 818 /**
 819  * \fn void Threads_Sleep(void)
 820  * \brief Take the current process off the run queue
 821  */
 822 void Threads_Sleep(void)
 823 {
 824         tThread *cur = Proc_GetCurThread();
 825
 826         // Acquire Spinlock
 827         SHORTLOCK( &glThreadListLock );
 828
 829         // Don't sleep if there is a message waiting
 830         if( cur->Messages ) {
 831                 SHORTREL( &glThreadListLock );
 832                 return;
 833         }
 834
 835         // Remove us from running queue
 836         Threads_RemActive();
 837         // Mark thread as sleeping
 838         cur->Status = THREAD_STAT_SLEEPING;
 839
 840         // Add to Sleeping List (at the top)
 841         Threads_int_AddToList( &gSleepingThreads, cur );
 842
 843         #if DEBUG_TRACE_STATE
 844         Log("Threads_Sleep: %p (%i %s) sleeping", cur, cur->TID, cur->ThreadName);
 845         #endif
 846
 847         // Release Spinlock
 848         SHORTREL( &glThreadListLock );
 849         Threads_int_WaitForStatusEnd(THREAD_STAT_SLEEPING);
 850 }
 851
 852
 853 /**
 854  * \brief Wakes a sleeping/waiting thread up
 855  * \param Thread        Thread to wake
 856  * \return Boolean Failure (Returns ERRNO)
 857  * \warning This should ONLY be called with task switches disabled
 858  */
 859 int Threads_Wake(tThread *Thread)
 860 {
 861         if(!Thread)
 862                 return -EINVAL;
 863
 864         switch(Thread->Status)
 865         {
 866         case THREAD_STAT_ACTIVE:
 867                 Log("Threads_Wake - Waking awake thread (%i)", Thread->TID);
 868                 return -EALREADY;
 869
 870         case THREAD_STAT_SLEEPING:
 871                 // Remove from sleeping queue
 872                 SHORTLOCK( &glThreadListLock );
 873                 Threads_int_DelFromQueue(&gSleepingThreads, Thread);
 874                 SHORTREL( &glThreadListLock );
 875
 876                 Threads_AddActive( Thread );
 877
 878                 #if DEBUG_TRACE_STATE
 879                 Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName);
 880                 #endif
 881                 return -EOK;
 882
 883         case THREAD_STAT_SEMAPHORESLEEP: {
 884                 tSemaphore      *sem;
 885                 tThread *th, *prev=NULL;
 886
 887                 sem = Thread->WaitPointer;
 888
 889                 SHORTLOCK( &sem->Protector );
 890
 891                 // Remove from sleeping queue
 892                 for( th = sem->Waiting; th; prev = th, th = th->Next )
 893                         if( th == Thread )      break;
 894                 if( th )
 895                 {
 896                         if(prev)
 897                                 prev->Next = Thread->Next;
 898                         else
 899                                 sem->Waiting = Thread->Next;
 900                         if(sem->LastWaiting == Thread)
 901                                 sem->LastWaiting = prev;
 902                 }
 903                 else
 904                 {
 905                         prev = NULL;
 906                         for( th = sem->Signaling; th; prev = th, th = th->Next )
 907                                 if( th == Thread )      break;
 908                         if( !th ) {
 909                                 Log_Warning("Threads", "Thread %p(%i %s) is not on semaphore %p(%s:%s)",
 910                                         Thread, Thread->TID, Thread->ThreadName,
 911                                         sem, sem->ModName, sem->Name);
 912                                 return -EINTERNAL;
 913                         }
 914
 915                         if(prev)
 916                                 prev->Next = Thread->Next;
 917                         else
 918                                 sem->Signaling = Thread->Next;
 919                         if(sem->LastSignaling == Thread)
 920                                 sem->LastSignaling = prev;
 921                 }
 922
 923                 Thread->RetStatus = 0;  // It didn't get anything
 924                 Threads_AddActive( Thread );
 925
 926                 #if DEBUG_TRACE_STATE
 927                 Log("Threads_Sleep: %p(%i %s) woken from semaphore", Thread, Thread->TID, Thread->ThreadName);
 928                 #endif
 929                 SHORTREL( &sem->Protector );
 930                 } return -EOK;
 931
 932         case THREAD_STAT_WAITING:
 933                 Warning("Threads_Wake - Waiting threads are not currently supported");
 934                 return -ENOTIMPL;
 935
 936         case THREAD_STAT_DEAD:
 937                 Warning("Threads_Wake - Attempt to wake dead thread (%i)", Thread->TID);
 938                 return -ENOTIMPL;
 939
 940         default:
 941                 Log_Warning("Threads", "Threads_Wake - Unknown process status (%i)", Thread->Status);
 942                 return -EINTERNAL;
 943         }
 944 }
 945
 946 /**
 947  * \brief Wake a thread given the TID
 948  * \param TID   Thread ID to wake
 949  * \return Boolean Faulure (errno)
 950  */
 951 int Threads_WakeTID(tTID TID)
 952 {
 953         tThread *thread = Threads_GetThread(TID);
 954          int    ret;
 955         if(!thread)
 956                 return -ENOENT;
 957         ret = Threads_Wake( thread );
 958         //Log_Debug("Threads", "TID %i woke %i (%p)", Threads_GetTID(), TID, thread);
 959         return ret;
 960 }
 961
 962 void Threads_ToggleTrace(int TID)
 963 {
 964         tThread *thread = Threads_GetThread(TID);
 965         if(!thread)     return ;
 966         thread->bInstrTrace = !thread->bInstrTrace;
 967 }
 968
 969 /**
 970  * \brief Adds a thread to the active queue
 971  */
 972 void Threads_AddActive(tThread *Thread)
 973 {
 974         #if DEBUG_TRACE_ACTIVEQUEUE
 975         Debug("Threads_AddActive("PRIthread_fmt")", PRIthread_args(Thread));
 976         #endif
 977         SHORTLOCK( &glThreadListLock );
 978
 979         if( Thread->Status == THREAD_STAT_ACTIVE )
 980         {
 981                 tThread *cur = Proc_GetCurThread();
 982                 Log_KernelPanic("Threads",
 983                         "ret=%p CPU%i "PRIthread_fmt" is adding "PRIthread_fmt" when it is active",
 984                         __builtin_return_address(0),
 985                         GetCPUNum(), PRIthread_args(cur), PRIthread_args(Thread));
 986                 SHORTREL( &glThreadListLock );
 987                 return ;
 988         }
 989
 990         // Set state
 991         Thread->Status = THREAD_STAT_ACTIVE;
 992         // Add to active list
 993         // - Thread can be the current thread if we're interrupted just before
 994         //   Proc_Reschedule in a sleep state.
 995         if( Thread != Proc_GetCurThread() )
 996         {
 997                 #if SCHEDULER_TYPE == SCHED_RR_PRI
 998                 tThreadList     *list = &gaActiveThreads[Thread->Priority];
 999                 #else
1000                 tThreadList     *list = &gActiveThreads;
1001                 #endif
1002                 #if DEBUG_TRACE_ACTIVEQUEUE
1003                 Debug(" - Head="PRIthread_fmt",Tail="PRIthread_fmt"",
1004                         PRIthread_args(list->Head),
1005                         PRIthread_args(list->Tail)
1006                         );
1007                 #endif
1008                 Threads_int_AddToList( list, Thread );
1009         }
1010
1011         // Update bookkeeping
1012         giNumActiveThreads ++;
1013
1014         #if SCHEDULER_TYPE == SCHED_LOTTERY
1015         {
1016                  int    delta;
1017                 // Only change the ticket count if the thread is un-scheduled
1018                 if(Thread->CurCPU != -1)
1019                         delta = 0;
1020                 else
1021                         delta = caiTICKET_COUNTS[ Thread->Priority ];
1022
1023                 giFreeTickets += delta;
1024                 # if DEBUG_TRACE_TICKETS
1025                 Log("CPU%i %p (%i %s) added, new giFreeTickets = %i [+%i]",
1026                         GetCPUNum(), Thread, Thread->TID, Thread->ThreadName,
1027                         giFreeTickets, delta
1028                         );
1029                 # endif
1030         }
1031         #endif
1032
1033         SHORTREL( &glThreadListLock );
1034 }
1035
1036 /**
1037  * \brief Removes the current thread from the active queue
1038  * \warning This should ONLY be called with the lock held
1039  * \return Current thread pointer
1040  */
1041 tThread *Threads_RemActive(void)
1042 {
1043         tThread *us = Proc_GetCurThread();
1044         #if DEBUG_TRACE_ACTIVEQUEUE
1045         Debug("Threads_RemActive(%p(%i %s))", us, us->TID, us->ThreadName);
1046         #endif
1047         giNumActiveThreads --;
1048         return us;
1049 }
1050
1051 /**
1052  * \fn void Threads_SetFaultHandler(Uint Handler)
1053  * \brief Sets the signal handler for a signal
1054  */
1055 void Threads_SetFaultHandler(Uint Handler)
1056 {
1057         //Log_Debug("Threads", "Threads_SetFaultHandler: Handler = %p", Handler);
1058         Proc_GetCurThread()->FaultHandler = Handler;
1059 }
1060
1061 /**
1062  * \fn void Threads_Fault(int Num)
1063  * \brief Calls a fault handler
1064  */
1065 void Threads_Fault(int Num)
1066 {
1067         tThread *thread = Proc_GetCurThread();
1068
1069         if(!thread)     return ;
1070
1071         Log_Log("Threads", "Threads_Fault: thread->FaultHandler = %p", thread->FaultHandler);
1072
1073         switch(thread->FaultHandler)
1074         {
1075         case 0: // Panic?
1076                 Threads_Kill(thread, -1);
1077                 HALT();
1078                 return ;
1079         case 1: // Dump Core?
1080                 Threads_Kill(thread, -1);
1081                 HALT();
1082                 return ;
1083         }
1084
1085         // Double Fault? Oh, F**k
1086         if(thread->CurFaultNum != 0) {
1087                 Log_Warning("Threads", "Threads_Fault: Double fault on %i", thread->TID);
1088                 Threads_Kill(thread, -1);       // For now, just kill
1089                 HALT();
1090         }
1091
1092         thread->CurFaultNum = Num;
1093
1094         Proc_CallFaultHandler(thread);
1095 }
1096
1097 /**
1098  * \fn void Threads_SegFault(tVAddr Addr)
1099  * \brief Called when a Segment Fault occurs
1100  */
1101 void Threads_SegFault(tVAddr Addr)
1102 {
1103         tThread *cur = Proc_GetCurThread();
1104         cur->bInstrTrace = 0;
1105         Log_Warning("Threads", "Thread #%i committed a segfault at address %p", cur->TID, Addr);
1106         MM_DumpTables(0, USER_MAX);
1107         Threads_Fault( 1 );
1108         //Threads_Exit( 0, -1 );
1109 }
1110
1111
1112 void Threads_PostSignalTo(tThread *Thread, int SignalNum)
1113 {
1114         ASSERT(Thread);
1115         Log_Debug("Threads", "Signalling %i(%s) with %i", Thread->TID, Thread->ThreadName, SignalNum);
1116         Thread->PendingSignal = SignalNum;
1117         Threads_PostEvent(Thread, THREAD_EVENT_SIGNAL);
1118 }
1119 void Threads_PostSignal(int SignalNum)
1120 {
1121         Threads_PostSignalTo( Proc_GetCurThread(), SignalNum );
1122 }
1123
1124 void Threads_SignalGroup(tPGID PGID, int Signal)
1125 {
1126         for( tProcess *proc = gAllProcesses; proc; proc = proc->Next )
1127         {
1128                 if(proc->PGID == PGID)
1129                 {
1130                         Threads_PostSignalTo(proc->FirstThread, Signal);
1131                 }
1132         }
1133 }
1134
1135 /**
1136  */
1137 int Threads_GetPendingSignal(void)
1138 {
1139         tThread *cur = Proc_GetCurThread();
1140
1141         // Atomic AND with 0 fetches and clears in one operation
1142         int ret = __sync_fetch_and_and( &cur->PendingSignal, 0 );
1143         if( ret )
1144         {
1145                 Log_Debug("Threads", "Thread %i(%s) has signal %i pending",
1146                         cur->TID, cur->ThreadName, ret);
1147         }
1148         return ret;
1149 }
1150
1151 /*
1152  * \brief Update the current thread's signal handler
1153  */
1154 void Threads_SetSignalHandler(int SignalNum, void *Handler)
1155 {
1156         if( SignalNum <= 0 || SignalNum >= NSIGNALS )
1157                 return ;
1158         if( !MM_IsUser(Handler) )
1159                 return ;
1160         Proc_GetCurThread()->Process->SignalHandlers[SignalNum] = Handler;
1161 }
1162
1163 /**
1164  * \brief Gets the registered (or default, if none set) handler for a signal.
1165  * \return Handler function pointer, OR NULL if no signal to be ignored
1166  */
1167 void *Threads_GetSignalHandler(int SignalNum)
1168 {
1169         // TODO: Core dump
1170         void *User_Signal_Core = User_Signal_Kill;
1171
1172         if( SignalNum <= 0 || SignalNum >= NSIGNALS )
1173                 return NULL;
1174         void *ret = Proc_GetCurThread()->Process->SignalHandlers[SignalNum];
1175         if( !ret || (SignalNum == SIGKILL || SignalNum == SIGSTOP) )
1176         {
1177                 // Defaults
1178                 switch(SignalNum)
1179                 {
1180                 case SIGHUP:
1181                 case SIGINT:
1182                         ret = User_Signal_Kill;
1183                         break;
1184                 case SIGQUIT:
1185                 case SIGILL:
1186                 case SIGABRT:
1187                 case SIGFPE:
1188                         ret = User_Signal_Core;
1189                         break;
1190                 case SIGKILL:
1191                         ret = User_Signal_Kill;
1192                         break;
1193                 case SIGSEGV:
1194                         ret = User_Signal_Core;
1195                         break;
1196                 case SIGPIPE:
1197                 case SIGALRM:
1198                 case SIGTERM:
1199                         ret = User_Signal_Kill;
1200                         break;
1201                 default:
1202                         ret = NULL;
1203                         break;
1204                 }
1205         }
1206         Log_Debug("Threads", "Handler %p for signal %i", ret, SignalNum);
1207         return ret;
1208 }
1209
1210 // --- Process Structure Access Functions ---
1211 tPGID Threads_GetPGID(void)
1212 {
1213         return Proc_GetCurThread()->Process->PGID;
1214 }
1215 tPID Threads_GetPID(void)
1216 {
1217         return Proc_GetCurThread()->Process->PID;
1218 }
1219 tTID Threads_GetTID(void)
1220 {
1221         return Proc_GetCurThread()->TID;
1222 }
1223 tUID Threads_GetUID(void)
1224 {
1225         return Proc_GetCurThread()->Process->UID;
1226 }
1227 tGID Threads_GetGID(void)
1228 {
1229         return Proc_GetCurThread()->Process->GID;
1230 }
1231
1232 int Threads_SetUID(tUID ID)
1233 {
1234         tThread *t = Proc_GetCurThread();
1235         if( t->Process->UID != 0 ) {
1236                 errno = -EACCES;
1237                 return -1;
1238         }
1239         Log_Debug("Threads", "PID %i's UID set to %i", t->Process->PID, ID);
1240         t->Process->UID = ID;
1241         return 0;
1242 }
1243
1244 int Threads_SetGID(tGID ID)
1245 {
1246         tThread *t = Proc_GetCurThread();
1247         if( t->Process->UID != 0 ) {
1248                 errno = -EACCES;
1249                 return -1;
1250         }
1251         Log_Debug("Threads", "PID %i's GID set to %i", t->Process->PID, ID);
1252         t->Process->GID = ID;
1253         return 0;
1254 }
1255
1256 // --- Per-thread storage ---
1257 int *Threads_GetErrno(void)
1258 {
1259         return &Proc_GetCurThread()->_errno;
1260 }
1261
1262 // --- Configuration ---
1263 int *Threads_GetMaxFD(tProcess *Process)
1264 {
1265         if(!Process)    Process = Proc_GetCurThread()->Process;
1266         return &Process->MaxFD;
1267 }
1268 char **Threads_GetChroot(tProcess *Process)
1269 {
1270         if(!Process)    Process = Proc_GetCurThread()->Process;
1271         return &Process->RootDir;
1272 }
1273 char **Threads_GetCWD(tProcess *Process)
1274 {
1275         if(!Process)    Process = Proc_GetCurThread()->Process;
1276         return &Process->CurrentWorkingDir;
1277 }
1278 // ---
1279
1280 void Threads_int_DumpThread(tThread *thread)
1281 {
1282         if( !thread ) {
1283                 Log(" %p NULL", thread);
1284                 return ;
1285         }
1286         if( !CheckMem(thread, sizeof(tThread)) ) {
1287                 Log(" %p INVAL", thread);
1288                 return ;
1289         }
1290         tPID    pid = (thread->Process ? thread->Process->PID : -1);
1291         const char      *statstr = (thread->Status < sizeof(casTHREAD_STAT)/sizeof(casTHREAD_STAT[0])
1292                 ? casTHREAD_STAT[thread->Status] : "");
1293         Log(" %p %i (%i) - %s (CPU %i) - %i (%s)",
1294                 thread, thread->TID, pid, thread->ThreadName, thread->CurCPU,
1295                 thread->Status, statstr
1296                 );
1297         switch(thread->Status)
1298         {
1299         case THREAD_STAT_MUTEXSLEEP:
1300                 Log("  Mutex Pointer: %p", thread->WaitPointer);
1301                 break;
1302         case THREAD_STAT_RWLOCKSLEEP:
1303                 Log("  Lock Pointer: %p", thread->WaitPointer);
1304                 Log("  Lock Name: %s",
1305                         ((tRWLock*)thread->WaitPointer)->Name);
1306                 break;
1307         case THREAD_STAT_SEMAPHORESLEEP:
1308                 Log("  Semaphore Pointer: %p", thread->WaitPointer);
1309                 Log("  Semaphore Name: %s:%s",
1310                         ((tSemaphore*)thread->WaitPointer)->ModName,
1311                         ((tSemaphore*)thread->WaitPointer)->Name
1312                         );
1313                 break;
1314         case THREAD_STAT_EVENTSLEEP:
1315                 Log("  Event Mask: %x", thread->RetStatus);
1316                 break;
1317         case THREAD_STAT_ZOMBIE:
1318                 Log("  Return Status: %i", thread->RetStatus);
1319                 break;
1320         default:        break;
1321         }
1322         Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
1323         Log("  KStack %p", thread->KernelStack);
1324         if( thread->bInstrTrace )
1325                 Log("  Tracing Enabled");
1326         Proc_DumpThreadCPUState(thread);
1327 }
1328
1329 /**
1330  * \fn void Threads_Dump(void)
1331  */
1332 void Threads_DumpActive(void)
1333 {
1334         Log("Active Threads: (%i reported)", giNumActiveThreads);
1335
1336         #if SCHEDULER_TYPE == SCHED_RR_PRI
1337         for( int i = 0; i < MIN_PRIORITY+1; i++ )
1338         {
1339                 tThreadList *list = &gaActiveThreads[i];
1340         #else
1341                 tThreadList *list = &gActiveThreads;
1342         #endif
1343                 for(tThread *thread = list->Head; thread; thread = thread->Next)
1344                 {
1345                         Threads_int_DumpThread(thread);
1346                         if(thread->Status != THREAD_STAT_ACTIVE)
1347                                 Log("  ERROR State (%i) != THREAD_STAT_ACTIVE (%i)",
1348                                         thread->Status, THREAD_STAT_ACTIVE);
1349                 }
1350
1351         #if SCHEDULER_TYPE == SCHED_RR_PRI
1352         }
1353         #endif
1354 }
1355
1356 /**
1357  * \fn void Threads_Dump(void)
1358  * \brief Dumps a list of currently running threads
1359  */
1360 void Threads_Dump(void)
1361 {
1362         Log("--- Thread Dump ---");
1363         Threads_DumpActive();
1364
1365         Log("All Threads:");
1366         for(tThread *thread = gAllThreads; thread; thread = thread->GlobalNext)
1367         {
1368                 Threads_int_DumpThread(thread);
1369         }
1370 }
1371
1372 tThread *Threads_int_GetRunnable(void)
1373 {
1374         #if SCHEDULER_TYPE == SCHED_LOTTERY
1375         // -----------------------------------
1376         // Lottery Scheduler
1377         // -----------------------------------
1378         #if DEBUG_VALIDATE_TICKET_COUNTS
1379         {
1380                 int total_tickets = 0;
1381                 for(const tThread *thread = gActiveThreads.Head; thread; thread = thread->Next)
1382                 {
1383                         if(thread->Status != THREAD_STAT_ACTIVE)
1384                                 Panic("Bookkeeping fail - %p %i(%s) is on the active queue with a status of %i",
1385                                         thread, thread->TID, thread->ThreadName, thread->Status);
1386                         if(thread->Next == thread) {
1387                                 Panic("Bookkeeping fail - %p %i(%s) loops back on itself",
1388                                         thread, thread->TID, thread->ThreadName, thread->Status);
1389                         }
1390                         total_tickets += caiTICKET_COUNTS[ thread->Priority ];
1391                 }
1392                 if(total_tickets != giFreeTickets)
1393                 {
1394                         Panic("Bookkeeping fail (giFreeTickets(%i) != number(%i)) - CPU%i",
1395                                 giFreeTickets, total_tickets, CPU);
1396                 }
1397         }
1398         # endif
1399
1400         // No free tickets (all tasks delegated to cores)
1401         if( giFreeTickets == 0 )
1402         {
1403                 return NULL;
1404         }
1405
1406         // Get the ticket number
1407         int ticket = rand() % giFreeTickets;
1408         int number = ticket;
1409
1410         // Find the next thread
1411         tThread **pnp = &gActiveThreads.Head;
1412         tThread *thread;
1413         for(thread = gActiveThreads.Head; thread; pnp = &thread->Next, thread = thread->Next )
1414         {
1415                 if( caiTICKET_COUNTS[ thread->Priority ] > number)
1416                         break;
1417                 number -= caiTICKET_COUNTS[ thread->Priority ];
1418         }
1419
1420         // If we didn't find a thread, something went wrong
1421         if(thread == NULL)
1422         {
1423                 int total_tickets = 0;
1424                 for(thread=gActiveThreads;thread;thread=thread->Next) {
1425                         if(thread->CurCPU >= 0) continue;
1426                         total_tickets += caiTICKET_COUNTS[ thread->Priority ];
1427                 }
1428                 Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)",
1429                         giFreeTickets, total_tickets);
1430         }
1431
1432         // Remove
1433         *pnp = thread->Next;
1434         if( !thread->Next )
1435                 gActiveThreads.Tail = prev;
1436
1437         giFreeTickets -= caiTICKET_COUNTS[ thread->Priority ];
1438         # if DEBUG_TRACE_TICKETS
1439         LogF("Log: CPU%i allocated %p (%i %s), (%i [-%i] tickets in pool), \n",
1440                 CPU, thread, thread->TID, thread->ThreadName,
1441                 giFreeTickets, caiTICKET_COUNTS[ thread->Priority ]);
1442         # endif
1443         return thread;
1444
1445         #elif SCHEDULER_TYPE == SCHED_RR_PRI
1446
1447         // -----------------------------------
1448         // Priority based round robin scheduler
1449         // -----------------------------------
1450         for( int i = 0; i < MIN_PRIORITY + 1; i ++ )
1451         {
1452                 if( gaActiveThreads[i].Head == NULL )
1453                         continue ;
1454
1455                 tThread *thread = gaActiveThreads[i].Head;
1456
1457                 if( thread->Status != THREAD_STAT_ACTIVE ) {
1458                         for( const tThread *t = gaActiveThreads[i].Head; t; t = t->Next )
1459                                 LogF("- %p(%i %s)\n", t, t->TID, t->ThreadName);
1460                         Panic("Thread %p(%i %s) from pqueue %i is active!",
1461                                 thread, thread->TID, thread->ThreadName, i);
1462                 }
1463
1464                 // Remove from head
1465                 gaActiveThreads[i].Head = thread->Next;
1466                 if(!thread->Next)
1467                         gaActiveThreads[i].Tail = NULL;
1468                 thread->Next = NULL;
1469                 return thread;
1470         }
1471         return NULL;
1472
1473         #elif SCHEDULER_TYPE == SCHED_RR_SIM
1474
1475         // -----------------------------------
1476         // Single-list round-robin
1477         // -----------------------------------
1478         tThread *thread = gActiveThreads.Head;
1479         LOG("thread = %p", thread);
1480         if( thread )
1481         {
1482                 gActiveThreads.Head = thread->Next;
1483                 if(!thread->Next)
1484                         gaActiveThreads.Tail = NULL;
1485                 thread->Next = NULL;
1486         }
1487         return thread;
1488         #else
1489         # error "Unimplemented scheduling algorithm"
1490         return NULL;
1491         #endif
1492 }
1493
1494 /**
1495  * \brief Gets the next thread to run
1496  * \param CPU   Current CPU
1497  * \param Last  The thread the CPU was running
1498  */
1499 tThread *Threads_GetNextToRun(int CPU, tThread *Last)
1500 {
1501         ASSERT( CPU_HAS_LOCK(&glThreadListLock) );
1502
1503         // Don't change threads if the current CPU has switches disabled
1504         if( gaThreads_NoTaskSwitch[CPU] ) {
1505                 LOG("- Denied");
1506                 return Last;
1507         }
1508
1509         // Make sure the current (well, old) thread is marked as de-scheduled
1510         if(Last)        Last->CurCPU = -1;
1511
1512         // No active threads, just take a nap
1513         if(giNumActiveThreads == 0) {
1514                 LOG("- No active");
1515                 #if DEBUG_TRACE_TICKETS
1516                 Log("No active threads");
1517                 #endif
1518                 return NULL;
1519         }
1520
1521         // Allow the old thread to be scheduled again
1522         if( Last )
1523         {
1524                 if( Last->Status == THREAD_STAT_ACTIVE ) {
1525                         tThreadList     *list;
1526                         #if SCHEDULER_TYPE == SCHED_LOTTERY
1527                         giFreeTickets += caiTICKET_COUNTS[ Last->Priority ];
1528                         # if DEBUG_TRACE_TICKETS
1529                         LogF("Log: CPU%i released %p (%i %s) into the pool (%i [+%i] tickets in pool)\n",
1530                                 CPU, Last, Last->TID, Last->ThreadName, giFreeTickets,
1531                                 caiTICKET_COUNTS[ Last->Priority ]);
1532                         # endif
1533                         #endif
1534
1535                         #if SCHEDULER_TYPE == SCHED_RR_PRI
1536                         list = &gaActiveThreads[ Last->Priority ];
1537                         #else
1538                         list = &gActiveThreads;
1539                         #endif
1540                         // Add to end of list
1541                         Threads_int_AddToList( list, Last );
1542                         #if DEBUG_TRACE_ACTIVEQUEUE > 1
1543                         Debug("Threads_GetNextToRun: Append thread %p(%i %s)",
1544                                 Last, Last->TID, Last->ThreadName);
1545                         #endif
1546                 }
1547                 #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
1548                 else
1549                         LogF("Log: CPU%i released %p (%i %s)->Status = %i (Released,not in pool)\n",
1550                                 CPU, Last, Last->TID, Last->ThreadName, Last->Status);
1551                 #endif
1552                 Last->CurCPU = -1;
1553         }
1554
1555         // Call actual scheduler
1556         tThread *thread = Threads_int_GetRunnable();
1557
1558         // Anything to do?
1559         if( thread )
1560         {
1561                 if( thread->Status != THREAD_STAT_ACTIVE )
1562                 {
1563                         LogF("Thread %p(%i %s) scheduled while not active\n",
1564                                 thread, thread->TID, thread->ThreadName);
1565                 }
1566
1567                 // Make the new thread non-schedulable
1568                 thread->CurCPU = CPU;
1569                 thread->Remaining = thread->Quantum;
1570
1571                 #if DEBUG_TRACE_SCHEDULE
1572                 Debug("Scheduled "PRIthread_fmt", next = %p",
1573                         PRIthread_args(thread),
1574                         thread->Next);
1575                 #endif
1576         }
1577         else
1578         {
1579                 // No thread possible, warning condition (idle thread should be runnable)
1580                 Warning("No runnable thread for CPU%i", CPU);
1581         }
1582
1583         return thread;
1584 }
1585
1586 // === EXPORTS ===
1587 EXPORT(Threads_GetUID);
1588 EXPORT(Threads_GetGID);