KernelLand/Kernel/threads.c

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