Kernel/threads.c

   1 /*
   2  * Acess2
   3  * threads.c
   4  * - Common Thread Control
   5  */
   6 #include <acess.h>
   7 #include <threads.h>
   8 #include <threads_int.h>
   9 #include <errno.h>
  10 #include <mutex.h>
  11 #include <semaphore.h>
  12 #include <hal_proc.h>
  13
  14 // Configuration
  15 #define DEBUG_TRACE_TICKETS     0       // Trace ticket counts
  16 #define DEBUG_TRACE_STATE       0       // Trace state changes (sleep/wake)
  17 #define SEMAPHORE_DEBUG         0
  18
  19 // --- Schedulers ---
  20 #define SCHED_UNDEF     0
  21 #define SCHED_LOTTERY   1       // Lottery scheduler
  22 #define SCHED_RR_SIM    2       // Single Queue Round Robin
  23 #define SCHED_RR_PRI    3       // Multi Queue Round Robin
  24 // Set scheduler type
  25 #define SCHEDULER_TYPE  SCHED_RR_PRI
  26
  27 // === CONSTANTS ===
  28 #define DEFAULT_QUANTUM 5
  29 #define DEFAULT_PRIORITY        5
  30 #define MIN_PRIORITY            10
  31 const enum eConfigTypes cCONFIG_TYPES[] = {
  32         CFGT_HEAPSTR,   // e.g. CFG_VFS_CWD
  33         CFGT_INT,       // e.g. CFG_VFS_MAXFILES
  34         CFGT_NULL
  35 };
  36
  37 // === IMPORTS ===
  38
  39 // === PROTOTYPES ===
  40 void    Threads_Init(void);
  41 #if 0
  42  int    Threads_SetName(const char *NewName);
  43 #endif
  44 char    *Threads_GetName(int ID);
  45 #if 0
  46 void    Threads_SetPriority(tThread *Thread, int Pri);
  47 tThread *Threads_CloneTCB(Uint *Err, Uint Flags);
  48  int    Threads_WaitTID(int TID, int *status);
  49 tThread *Threads_GetThread(Uint TID);
  50 #endif
  51 void    Threads_AddToDelete(tThread *Thread);
  52 tThread *Threads_int_DelFromQueue(tThread **List, tThread *Thread);
  53 #if 0
  54 void    Threads_Exit(int TID, int Status);
  55 void    Threads_Kill(tThread *Thread, int Status);
  56 void    Threads_Yield(void);
  57 void    Threads_Sleep(void);
  58  int    Threads_Wake(tThread *Thread);
  59 void    Threads_AddActive(tThread *Thread);
  60 tThread *Threads_RemActive(void);
  61 #endif
  62 void    Threads_ToggleTrace(int TID);
  63 void    Threads_Fault(int Num);
  64 void    Threads_SegFault(tVAddr Addr);
  65 #if 0
  66  int    Threads_GetPID(void);
  67  int    Threads_GetTID(void);
  68 tUID    Threads_GetUID(void);
  69 tGID    Threads_GetGID(void);
  70  int    Threads_SetUID(Uint *Errno, tUID ID);
  71  int    Threads_SetGID(Uint *Errno, tUID ID);
  72 #endif
  73 void    Threads_Dump(void);
  74 void    Threads_DumpActive(void);
  75 #if 0
  76  int    Mutex_Acquire(tMutex *Mutex);
  77 void    Mutex_Release(tMutex *Mutex);
  78  int    Mutex_IsLocked(tMutex *Mutex);
  79 #endif
  80
  81 // === GLOBALS ===
  82 // -- Core Thread --
  83 // Only used for the core kernel
  84 tThread gThreadZero = {
  85         .Status         = THREAD_STAT_ACTIVE,   // Status
  86         .ThreadName     = (char*)"ThreadZero",  // Name
  87         .Quantum        = DEFAULT_QUANTUM,      // Default Quantum
  88         .Remaining      = DEFAULT_QUANTUM,      // Current Quantum
  89         .Priority       = DEFAULT_PRIORITY      // Number of tickets
  90         };
  91 // -- Processes --
  92 // --- Locks ---
  93 tShortSpinlock  glThreadListLock;       ///\note NEVER use a heap function while locked
  94 // --- Current State ---
  95 volatile int    giNumActiveThreads = 0; // Number of threads on the active queue
  96 volatile Uint   giNextTID = 1;  // Next TID to allocate
  97 // --- Thread Lists ---
  98 tThread *gAllThreads = NULL;            // All allocated threads
  99 tThread *gSleepingThreads = NULL;       // Sleeping Threads
 100 tThread *gDeleteThreads = NULL;         // Threads to delete
 101  int    giNumCPUs = 1;  // Number of CPUs
 102 BOOL     gaThreads_NoTaskSwitch[MAX_CPUS];      // Disables task switches for each core (Pseudo-IF)
 103 // --- Scheduler Types ---
 104 #if SCHEDULER_TYPE == SCHED_LOTTERY
 105 const int       caiTICKET_COUNTS[MIN_PRIORITY+1] = {100,81,64,49,36,25,16,9,4,1,0};
 106 volatile int    giFreeTickets = 0;      // Number of tickets held by non-scheduled threads
 107 tThread *gActiveThreads = NULL;         // Currently Running Threads
 108 #elif SCHEDULER_TYPE == SCHED_RR_SIM
 109 tThread *gActiveThreads = NULL;         // Currently Running Threads
 110 #elif SCHEDULER_TYPE == SCHED_RR_PRI
 111 tThread *gaActiveThreads[MIN_PRIORITY+1];       // Active threads for each priority level
 112 #else
 113 # error "Unkown scheduler type"
 114 #endif
 115
 116 // === CODE ===
 117 /**
 118  * \fn void Threads_Init(void)
 119  * \brief Initialse the thread list
 120  */
 121 void Threads_Init(void)
 122 {
 123         ArchThreads_Init();
 124
 125         Log_Debug("Threads", "Offsets of tThread");
 126         Log_Debug("Threads", ".Priority = %i", offsetof(tThread, Priority));
 127         Log_Debug("Threads", ".KernelStack = %i", offsetof(tThread, KernelStack));
 128
 129         // Create Initial Task
 130         #if SCHEDULER_TYPE == SCHED_RR_PRI
 131         gaActiveThreads[gThreadZero.Priority] = &gThreadZero;
 132         #else
 133         gActiveThreads = &gThreadZero;
 134         #endif
 135
 136         gAllThreads = &gThreadZero;
 137         giNumActiveThreads = 1;
 138
 139         Proc_Start();
 140 }
 141
 142 /**
 143  * \fn void Threads_SetName(const char *NewName)
 144  * \brief Sets the current thread's name
 145  * \param NewName       New name for the thread
 146  * \return Boolean Failure
 147  */
 148 int Threads_SetName(const char *NewName)
 149 {
 150         tThread *cur = Proc_GetCurThread();
 151         char    *oldname = cur->ThreadName;
 152
 153         // NOTE: There is a possibility of non-thread safety here
 154         // A thread could read the current name pointer before it is zeroed
 155
 156         cur->ThreadName = NULL;
 157
 158         if( IsHeap(oldname) )   free( oldname );
 159
 160         cur->ThreadName = strdup(NewName);
 161         return 0;
 162 }
 163
 164 /**
 165  * \fn char *Threads_GetName(int ID)
 166  * \brief Gets a thread's name
 167  * \param ID    Thread ID (-1 indicates current thread)
 168  * \return Pointer to name
 169  * \retval NULL Failure
 170  */
 171 char *Threads_GetName(tTID ID)
 172 {
 173         if(ID == -1) {
 174                 return Proc_GetCurThread()->ThreadName;
 175         }
 176         return Threads_GetThread(ID)->ThreadName;
 177 }
 178
 179 /**
 180  * \fn void Threads_SetPriority(tThread *Thread, int Pri)
 181  * \brief Sets the priority of a task
 182  * \param Thread        Thread to update ticket count (NULL means current thread)
 183  * \param Pri   New priority
 184  */
 185 void Threads_SetPriority(tThread *Thread, int Pri)
 186 {
 187         // Get current thread
 188         if(Thread == NULL)      Thread = Proc_GetCurThread();
 189         // Bounds checking
 190         // - If < 0, set to lowest priority
 191         // - Minumum priority is actualy a high number, 0 is highest
 192         if(Pri < 0)     Pri = MIN_PRIORITY;
 193         if(Pri > MIN_PRIORITY)  Pri = MIN_PRIORITY;
 194
 195         // Do we actually have to do anything?
 196         if( Pri == Thread->Priority )   return;
 197
 198         #if SCHEDULER_TYPE == SCHED_RR_PRI
 199         SHORTLOCK( &glThreadListLock );
 200         // Remove from old priority
 201         Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread );
 202         // And add to new
 203         Thread->Next = gaActiveThreads[Pri];
 204         gaActiveThreads[Pri] = Thread;
 205         Thread->Priority = Pri;
 206         SHORTREL( &glThreadListLock );
 207         #else
 208         // If this isn't the current thread, we need to lock
 209         if( Thread != Proc_GetCurThread() )
 210         {
 211                 SHORTLOCK( &glThreadListLock );
 212
 213                 #if SCHEDULER_TYPE == SCHED_LOTTERY
 214                 giFreeTickets -= caiTICKET_COUNTS[Thread->Priority] - caiTICKET_COUNTS[Pri];
 215                 # if DEBUG_TRACE_TICKETS
 216                 Log("Threads_SetTickets: new giFreeTickets = %i [-%i+%i]",
 217                         giFreeTickets,
 218                         caiTICKET_COUNTS[Thread->Priority], caiTICKET_COUNTS[Pri]);
 219                 # endif
 220                 #endif
 221                 Thread->Priority = Pri;
 222                 SHORTREL( &glThreadListLock );
 223         }
 224         else
 225                 Thread->Priority = Pri;
 226         #endif
 227
 228         #if DEBUG_TRACE_STATE
 229         Log("Threads_SetPriority: %p(%i %s) pri set %i",
 230                 Thread, Thread->TID, Thread->ThreadName,
 231                 Pri);
 232         #endif
 233 }
 234
 235 /**
 236  * \brief Clone the TCB of the current thread
 237  * \param Flags Flags for something... (What is this for?)
 238  */
 239 tThread *Threads_CloneTCB(Uint Flags)
 240 {
 241         tThread *cur, *new;
 242          int    i;
 243         cur = Proc_GetCurThread();
 244
 245         // Allocate and duplicate
 246         new = malloc(sizeof(tThread));
 247         if(new == NULL) { errno = -ENOMEM; return NULL; }
 248         memcpy(new, cur, sizeof(tThread));
 249
 250         new->CurCPU = -1;
 251         new->Next = NULL;
 252         memset( &new->IsLocked, 0, sizeof(new->IsLocked));
 253         new->Status = THREAD_STAT_PREINIT;
 254         new->RetStatus = 0;
 255
 256         // Get Thread ID
 257         new->TID = giNextTID++;
 258         new->Parent = cur;
 259         new->bInstrTrace = 0;
 260
 261         // Clone Name
 262         new->ThreadName = strdup(cur->ThreadName);
 263
 264         // Set Thread Group ID (PID)
 265         if(Flags & CLONE_VM)
 266                 new->TGID = new->TID;
 267         else
 268                 new->TGID = cur->TGID;
 269
 270         // Messages are not inherited
 271         new->Messages = NULL;
 272         new->LastMessage = NULL;
 273
 274         // Set State
 275         new->Remaining = new->Quantum = cur->Quantum;
 276         new->Priority = cur->Priority;
 277
 278         // Set Signal Handlers
 279         new->CurFaultNum = 0;
 280         new->FaultHandler = cur->FaultHandler;
 281
 282         for( i = 0; i < NUM_CFG_ENTRIES; i ++ )
 283         {
 284                 switch(cCONFIG_TYPES[i])
 285                 {
 286                 default:
 287                         new->Config[i] = cur->Config[i];
 288                         break;
 289                 case CFGT_HEAPSTR:
 290                         if(cur->Config[i])
 291                                 new->Config[i] = (Uint) strdup( (void*)cur->Config[i] );
 292                         else
 293                                 new->Config[i] = 0;
 294                         break;
 295                 }
 296         }
 297
 298         // Maintain a global list of threads
 299         SHORTLOCK( &glThreadListLock );
 300         new->GlobalPrev = NULL; // Protect against bugs
 301         new->GlobalNext = gAllThreads;
 302         gAllThreads->GlobalPrev = new;
 303         gAllThreads = new;
 304         SHORTREL( &glThreadListLock );
 305
 306         return new;
 307 }
 308
 309 /**
 310  * \brief Clone the TCB of the kernel thread
 311  */
 312 tThread *Threads_CloneThreadZero(void)
 313 {
 314         tThread *new;
 315          int    i;
 316
 317         // Allocate and duplicate
 318         new = malloc(sizeof(tThread));
 319         if(new == NULL) {
 320                 return NULL;
 321         }
 322         memcpy(new, &gThreadZero, sizeof(tThread));
 323
 324         new->CurCPU = -1;
 325         new->Next = NULL;
 326         memset( &new->IsLocked, 0, sizeof(new->IsLocked));
 327         new->Status = THREAD_STAT_PREINIT;
 328         new->RetStatus = 0;
 329
 330         // Get Thread ID
 331         new->TID = giNextTID++;
 332         new->Parent = 0;
 333
 334         // Clone Name
 335         new->ThreadName = NULL;
 336
 337         // Messages are not inherited
 338         new->Messages = NULL;
 339         new->LastMessage = NULL;
 340
 341         // Set State
 342         new->Remaining = new->Quantum = DEFAULT_QUANTUM;
 343         new->Priority = DEFAULT_PRIORITY;
 344         new->bInstrTrace = 0;
 345
 346         // Set Signal Handlers
 347         new->CurFaultNum = 0;
 348         new->FaultHandler = 0;
 349
 350         for( i = 0; i < NUM_CFG_ENTRIES; i ++ )
 351         {
 352                 new->Config[i] = 0;
 353         }
 354
 355         // Maintain a global list of threads
 356         SHORTLOCK( &glThreadListLock );
 357         new->GlobalPrev = NULL; // Protect against bugs
 358         new->GlobalNext = gAllThreads;
 359         gAllThreads->GlobalPrev = new;
 360         gAllThreads = new;
 361         SHORTREL( &glThreadListLock );
 362
 363         return new;
 364 }
 365
 366 /**
 367  * \brief Get a configuration pointer from the Per-Thread data area
 368  * \param ID    Config slot ID
 369  * \return Pointer at ID
 370  */
 371 Uint *Threads_GetCfgPtr(int ID)
 372 {
 373         if(ID < 0 || ID >= NUM_CFG_ENTRIES) {
 374                 Warning("Threads_GetCfgPtr: Index %i is out of bounds", ID);
 375                 return NULL;
 376         }
 377
 378         return &Proc_GetCurThread()->Config[ID];
 379 }
 380
 381 /**
 382  * \brief Wait for a task to change state
 383  * \param TID   Thread ID to wait on (-1: Any child thread, 0: Any Child/Sibling, <-1: -PID)
 384  * \param Status        Thread return status
 385  * \return TID of child that changed state
 386  */
 387 tTID Threads_WaitTID(int TID, int *Status)
 388 {
 389         // Any Child
 390         if(TID == -1) {
 391                 Log_Error("Threads", "TODO: Threads_WaitTID(TID=-1) - Any Child");
 392                 return -1;
 393         }
 394
 395         // Any peer/child thread
 396         if(TID == 0) {
 397                 Log_Error("Threads", "TODO: Threads_WaitTID(TID=0) - Any Child/Sibling");
 398                 return -1;
 399         }
 400
 401         // TGID = abs(TID)
 402         if(TID < -1) {
 403                 Log_Error("Threads", "TODO: Threads_WaitTID(TID<0) - TGID");
 404                 return -1;
 405         }
 406
 407         // Specific Thread
 408         if(TID > 0) {
 409                 tThread *t = Threads_GetThread(TID);
 410                  int    initStatus = t->Status;
 411                 tTID    ret;
 412
 413                 // Wait for the thread to die!
 414                 if(initStatus != THREAD_STAT_ZOMBIE) {
 415                         // TODO: Handle child also being suspended if wanted
 416                         while(t->Status != THREAD_STAT_ZOMBIE) {
 417                                 Threads_Sleep();
 418                                 Log_Debug("Threads", "%i waiting for %i, t->Status = %i",
 419                                         Threads_GetTID(), t->TID, t->Status);
 420                         }
 421                 }
 422
 423                 // Set return status
 424                 Log_Debug("Threads", "%i waiting for %i, t->Status = %i",
 425                         Threads_GetTID(), t->TID, t->Status);
 426                 ret = t->TID;
 427                 switch(t->Status)
 428                 {
 429                 case THREAD_STAT_ZOMBIE:
 430                         // Kill the thread
 431                         t->Status = THREAD_STAT_DEAD;
 432                         // TODO: Child return value?
 433                         if(Status)      *Status = t->RetStatus;
 434                         // add to delete queue
 435                         Threads_AddToDelete( t );
 436                         break;
 437                 default:
 438                         if(Status)      *Status = -1;
 439                         break;
 440                 }
 441                 return ret;
 442         }
 443
 444         return -1;
 445 }
 446
 447 /**
 448  * \brief Gets a thread given its TID
 449  * \param TID   Thread ID
 450  * \return Thread pointer
 451  */
 452 tThread *Threads_GetThread(Uint TID)
 453 {
 454         tThread *thread;
 455
 456         // Search global list
 457         for(thread = gAllThreads;
 458                 thread;
 459                 thread = thread->GlobalNext)
 460         {
 461                 if(thread->TID == TID)
 462                         return thread;
 463         }
 464
 465         Log("Unable to find TID %i on main list\n", TID);
 466
 467         return NULL;
 468 }
 469
 470 /**
 471  * \brief Adds a thread to the delete queue
 472  * \param Thread        Thread to delete
 473  */
 474 void Threads_AddToDelete(tThread *Thread)
 475 {
 476         // Add to delete queue
 477         // TODO: Is locking needed?
 478         if(gDeleteThreads) {
 479                 Thread->Next = gDeleteThreads;
 480                 gDeleteThreads = Thread;
 481         } else {
 482                 Thread->Next = NULL;
 483                 gDeleteThreads = Thread;
 484         }
 485 }
 486
 487 /**
 488  * \brief Deletes an entry from a list
 489  * \param List  Pointer to the list head
 490  * \param Thread        Thread to find
 491  * \return \a Thread
 492  */
 493 tThread *Threads_int_DelFromQueue(tThread **List, tThread *Thread)
 494 {
 495         tThread *ret, *prev = NULL;
 496
 497         for(ret = *List;
 498                 ret && ret != Thread;
 499                 prev = ret, ret = ret->Next
 500                 );
 501
 502         // Is the thread on the list
 503         if(!ret) {
 504                 //LogF("%p(%s) is not on list %p\n", Thread, Thread->ThreadName, List);
 505                 return NULL;
 506         }
 507
 508         if( !prev ) {
 509                 *List = Thread->Next;
 510                 //LogF("%p(%s) removed from head of %p\n", Thread, Thread->ThreadName, List);
 511         }
 512         else {
 513                 prev->Next = Thread->Next;
 514                 //LogF("%p(%s) removed from %p (prev=%p)\n", Thread, Thread->ThreadName, List, prev);
 515         }
 516
 517         return Thread;
 518 }
 519
 520 /**
 521  * \brief Exit the current process (or another?)
 522  * \param TID   Thread ID to kill
 523  * \param Status        Exit status
 524  */
 525 void Threads_Exit(int TID, int Status)
 526 {
 527         if( TID == 0 )
 528                 Threads_Kill( Proc_GetCurThread(), (Uint)Status & 0xFF );
 529         else
 530                 Threads_Kill( Threads_GetThread(TID), (Uint)Status & 0xFF );
 531
 532         // Halt forever, just in case
 533         for(;;) HALT();
 534 }
 535
 536 /**
 537  * \fn void Threads_Kill(tThread *Thread, int Status)
 538  * \brief Kill a thread
 539  * \param Thread        Thread to kill
 540  * \param Status        Status code to return to the parent
 541  */
 542 void Threads_Kill(tThread *Thread, int Status)
 543 {
 544         tMsg    *msg;
 545          int    isCurThread = Thread == Proc_GetCurThread();
 546
 547         // TODO: Kill all children
 548         #if 1
 549         {
 550                 tThread *child;
 551                 // TODO: I should keep a .Parent pointer, and a .Children list
 552                 for(child = gAllThreads;
 553                         child;
 554                         child = child->GlobalNext)
 555                 {
 556                         if(child->Parent == Thread)
 557                                 Threads_Kill(child, -1);
 558                 }
 559         }
 560         #endif
 561
 562         ///\note Double lock is needed due to overlap of lock areas
 563
 564         // Lock thread (stop us recieving messages)
 565         SHORTLOCK( &Thread->IsLocked );
 566
 567         // Clear Message Queue
 568         while( Thread->Messages )
 569         {
 570                 msg = Thread->Messages->Next;
 571                 free( Thread->Messages );
 572                 Thread->Messages = msg;
 573         }
 574
 575         // Lock thread list
 576         SHORTLOCK( &glThreadListLock );
 577
 578         switch(Thread->Status)
 579         {
 580         case THREAD_STAT_PREINIT:       // Only on main list
 581                 break;
 582
 583         // Currently active thread
 584         case THREAD_STAT_ACTIVE:
 585                 #if SCHEDULER_TYPE == SCHED_RR_PRI
 586                 if( Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread ) )
 587                 #else
 588                 if( Threads_int_DelFromQueue( &gActiveThreads, Thread ) )
 589                 #endif
 590                 {
 591                         // Ensure that we are not rescheduled
 592                         Thread->Remaining = 0;  // Clear Remaining Quantum
 593                         Thread->Quantum = 0;    // Clear Quantum to indicate dead thread
 594
 595                         // Update bookkeeping
 596                         giNumActiveThreads --;
 597                         #if SCHEDULER_TYPE == SCHED_LOTTERY
 598                         if( Thread != Proc_GetCurThread() )
 599                                 giFreeTickets -= caiTICKET_COUNTS[ Thread->Priority ];
 600                         #endif
 601                 }
 602                 else
 603                 {
 604                         Log_Warning("Threads",
 605                                 "Threads_Kill - Thread %p(%i,%s) marked as active, but not on list",
 606                                 Thread, Thread->TID, Thread->ThreadName
 607                                 );
 608                 }
 609                 break;
 610         // Kill it while it sleeps!
 611         case THREAD_STAT_SLEEPING:
 612                 if( !Threads_int_DelFromQueue( &gSleepingThreads, Thread ) )
 613                 {
 614                         Log_Warning("Threads",
 615                                 "Threads_Kill - Thread %p(%i,%s) marked as sleeping, but not on list",
 616                                 Thread, Thread->TID, Thread->ThreadName
 617                                 );
 618                 }
 619                 break;
 620
 621         // Brains!... You cannot kill
 622         case THREAD_STAT_ZOMBIE:
 623                 Log_Warning("Threads", "Threads_Kill - Thread %p(%i,%s) is undead, you cannot kill it",
 624                         Thread, Thread->TID, Thread->ThreadName);
 625                 SHORTREL( &glThreadListLock );
 626                 SHORTREL( &Thread->IsLocked );
 627                 return ;
 628
 629         default:
 630                 Log_Warning("Threads", "Threads_Kill - BUG Un-checked status (%i)",
 631                         Thread->Status);
 632                 break;
 633         }
 634
 635         // Save exit status
 636         Thread->RetStatus = Status;
 637
 638         // Don't Zombie if we are being killed because our parent is
 639         if(Status == -1)
 640         {
 641                 Thread->Status = THREAD_STAT_DEAD;
 642                 Threads_AddToDelete( Thread );
 643         } else {
 644                 Thread->Status = THREAD_STAT_ZOMBIE;
 645                 // Wake parent
 646                 Threads_Wake( Thread->Parent );
 647         }
 648
 649         Log("Thread %i went *hurk* (%i)", Thread->TID, Status);
 650
 651         // Release spinlocks
 652         SHORTREL( &glThreadListLock );
 653         SHORTREL( &Thread->IsLocked );  // TODO: We may not actually be released...
 654
 655         // And, reschedule
 656         if(isCurThread)
 657         {
 658                 for( ;; )
 659                         Proc_Reschedule();
 660         }
 661 }
 662
 663 /**
 664  * \brief Yield remainder of the current thread's timeslice
 665  */
 666 void Threads_Yield(void)
 667 {
 668         Log("Threads_Yield: by %p", __builtin_return_address(0));
 669         Proc_Reschedule();
 670 }
 671
 672 /**
 673  * \fn void Threads_Sleep(void)
 674  * \brief Take the current process off the run queue
 675  */
 676 void Threads_Sleep(void)
 677 {
 678         tThread *cur = Proc_GetCurThread();
 679
 680         // Acquire Spinlock
 681         SHORTLOCK( &glThreadListLock );
 682
 683         // Don't sleep if there is a message waiting
 684         if( cur->Messages ) {
 685                 SHORTREL( &glThreadListLock );
 686                 return;
 687         }
 688
 689         // Remove us from running queue
 690         Threads_RemActive();
 691         // Mark thread as sleeping
 692         cur->Status = THREAD_STAT_SLEEPING;
 693
 694         // Add to Sleeping List (at the top)
 695         cur->Next = gSleepingThreads;
 696         gSleepingThreads = cur;
 697
 698
 699         #if DEBUG_TRACE_STATE
 700         Log("Threads_Sleep: %p (%i %s) sleeping", cur, cur->TID, cur->ThreadName);
 701         #endif
 702
 703         // Release Spinlock
 704         SHORTREL( &glThreadListLock );
 705
 706         while(cur->Status != THREAD_STAT_ACTIVE) {
 707                 Proc_Reschedule();
 708                 if( cur->Status != THREAD_STAT_ACTIVE )
 709                         Log("%i - Huh? why am I up? zzzz...", cur->TID);
 710         }
 711 }
 712
 713
 714 /**
 715  * \fn int Threads_Wake( tThread *Thread )
 716  * \brief Wakes a sleeping/waiting thread up
 717  * \param Thread        Thread to wake
 718  * \return Boolean Failure (Returns ERRNO)
 719  * \warning This should ONLY be called with task switches disabled
 720  */
 721 int Threads_Wake(tThread *Thread)
 722 {
 723         if(!Thread)
 724                 return -EINVAL;
 725
 726         switch(Thread->Status)
 727         {
 728         case THREAD_STAT_ACTIVE:
 729                 Log("Threads_Wake - Waking awake thread (%i)", Thread->TID);
 730                 return -EALREADY;
 731
 732         case THREAD_STAT_SLEEPING:
 733                 SHORTLOCK( &glThreadListLock );
 734                 // Remove from sleeping queue
 735                 Threads_int_DelFromQueue(&gSleepingThreads, Thread);
 736
 737                 Threads_AddActive( Thread );
 738
 739                 #if DEBUG_TRACE_STATE
 740                 Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName);
 741                 #endif
 742                 SHORTREL( &glThreadListLock );
 743                 return -EOK;
 744
 745         case THREAD_STAT_SEMAPHORESLEEP: {
 746                 tSemaphore      *sem;
 747                 tThread *th, *prev=NULL;
 748
 749                 sem = Thread->WaitPointer;
 750
 751                 SHORTLOCK( &sem->Protector );
 752
 753                 // Remove from sleeping queue
 754                 for( th = sem->Waiting; th; prev = th, th = th->Next )
 755                         if( th == Thread )      break;
 756                 if( th )
 757                 {
 758                         if(prev)
 759                                 prev->Next = Thread->Next;
 760                         else
 761                                 sem->Waiting = Thread->Next;
 762                         if(sem->LastWaiting == Thread)
 763                                 sem->LastWaiting = prev;
 764                 }
 765                 else
 766                 {
 767                         prev = NULL;
 768                         for( th = sem->Signaling; th; prev = th, th = th->Next )
 769                                 if( th == Thread )      break;
 770                         if( !th ) {
 771                                 Log_Warning("Threads", "Thread %p(%i %s) is not on semaphore %p(%s:%s)",
 772                                         Thread, Thread->TID, Thread->ThreadName,
 773                                         sem, sem->ModName, sem->Name);
 774                                 return -EINTERNAL;
 775                         }
 776
 777                         if(prev)
 778                                 prev->Next = Thread->Next;
 779                         else
 780                                 sem->Signaling = Thread->Next;
 781                         if(sem->LastSignaling == Thread)
 782                                 sem->LastSignaling = prev;
 783                 }
 784
 785                 SHORTLOCK( &glThreadListLock );
 786                 Threads_AddActive( Thread );
 787                 SHORTREL( &glThreadListLock );
 788
 789                 #if DEBUG_TRACE_STATE
 790                 Log("Threads_Sleep: %p(%i %s) woken from semaphore", Thread, Thread->TID, Thread->ThreadName);
 791                 #endif
 792                 SHORTREL( &sem->Protector );
 793                 } return -EOK;
 794
 795         case THREAD_STAT_WAITING:
 796                 Warning("Threads_Wake - Waiting threads are not currently supported");
 797                 return -ENOTIMPL;
 798
 799         case THREAD_STAT_DEAD:
 800                 Warning("Threads_Wake - Attempt to wake dead thread (%i)", Thread->TID);
 801                 return -ENOTIMPL;
 802
 803         default:
 804                 Warning("Threads_Wake - Unknown process status (%i)\n", Thread->Status);
 805                 return -EINTERNAL;
 806         }
 807 }
 808
 809 /**
 810  * \brief Wake a thread given the TID
 811  * \param TID   Thread ID to wake
 812  * \return Boolean Faulure (errno)
 813  */
 814 int Threads_WakeTID(tTID TID)
 815 {
 816         tThread *thread = Threads_GetThread(TID);
 817          int    ret;
 818         if(!thread)
 819                 return -ENOENT;
 820         ret = Threads_Wake( thread );
 821         //Log_Debug("Threads", "TID %i woke %i (%p)", Threads_GetTID(), TID, thread);
 822         return ret;
 823 }
 824
 825 void Threads_ToggleTrace(int TID)
 826 {
 827         tThread *thread = Threads_GetThread(TID);
 828         if(!thread)     return ;
 829         thread->bInstrTrace = !thread->bInstrTrace;
 830 }
 831
 832 /**
 833  * \brief Adds a thread to the active queue
 834  */
 835 void Threads_AddActive(tThread *Thread)
 836 {
 837         SHORTLOCK( &glThreadListLock );
 838
 839         if( Thread->Status == THREAD_STAT_ACTIVE ) {
 840                 tThread *cur = Proc_GetCurThread();
 841                 Log_Warning("Threads", "WTF, %p CPU%i %p (%i %s) is adding %p (%i %s) when it is active",
 842                         __builtin_return_address(0),
 843                         GetCPUNum(), cur, cur->TID, cur->ThreadName, Thread, Thread->TID, Thread->ThreadName);
 844                 SHORTREL( &glThreadListLock );
 845                 return ;
 846         }
 847
 848         // Set state
 849         Thread->Status = THREAD_STAT_ACTIVE;
 850 //      Thread->CurCPU = -1;
 851         // Add to active list
 852         {
 853                 tThread *tmp, *prev = NULL;
 854                 #if SCHEDULER_TYPE == SCHED_RR_PRI
 855                 for( tmp = gaActiveThreads[Thread->Priority]; tmp; prev = tmp, tmp = tmp->Next );
 856                 if(prev)
 857                         prev->Next = Thread;
 858                 else
 859                         gaActiveThreads[Thread->Priority] = Thread;
 860                 #else
 861                 for( tmp = gActiveThreads; tmp; prev = tmp, tmp = tmp->Next );
 862                 if(prev)
 863                         prev->Next = Thread;
 864                 else
 865                         gActiveThreads = Thread;
 866                 #endif
 867                 Thread->Next = NULL;
 868         }
 869
 870         // Update bookkeeping
 871         giNumActiveThreads ++;
 872
 873         #if SCHEDULER_TYPE == SCHED_LOTTERY
 874         {
 875                  int    delta;
 876                 // Only change the ticket count if the thread is un-scheduled
 877                 if(Thread->CurCPU != -1)
 878                         delta = 0;
 879                 else
 880                         delta = caiTICKET_COUNTS[ Thread->Priority ];
 881
 882                 giFreeTickets += delta;
 883                 # if DEBUG_TRACE_TICKETS
 884                 Log("CPU%i %p (%i %s) added, new giFreeTickets = %i [+%i]",
 885                         GetCPUNum(), Thread, Thread->TID, Thread->ThreadName,
 886                         giFreeTickets, delta
 887                         );
 888                 # endif
 889         }
 890         #endif
 891
 892         SHORTREL( &glThreadListLock );
 893 }
 894
 895 /**
 896  * \brief Removes the current thread from the active queue
 897  * \warning This should ONLY be called with the lock held
 898  * \return Current thread pointer
 899  */
 900 tThread *Threads_RemActive(void)
 901 {
 902         tThread *ret = Proc_GetCurThread();
 903
 904         if( !IS_LOCKED(&glThreadListLock) ) {
 905                 Log_KernelPanic("Threads", "Threads_RemActive called without lock held");
 906                 return NULL;
 907         }
 908
 909         // Delete from active queue
 910         #if SCHEDULER_TYPE == SCHED_RR_PRI
 911         if( !Threads_int_DelFromQueue(&gaActiveThreads[ret->Priority], ret) )
 912         #else
 913         if( !Threads_int_DelFromQueue(&gActiveThreads, ret) )
 914         #endif
 915         {
 916                 SHORTREL( &glThreadListLock );
 917                 Log_Warning("Threads", "Current thread %p(%i %s) is not on active queue",
 918                         ret, ret->TID, ret->ThreadName
 919                         );
 920                 return NULL;
 921         }
 922
 923         ret->Next = NULL;
 924         ret->Remaining = 0;
 925
 926         giNumActiveThreads --;
 927         // no need to decrement tickets, scheduler did it for us
 928
 929         #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
 930         Log("CPU%i %p (%i %s) removed, giFreeTickets = %i [nc]",
 931                 GetCPUNum(), ret, ret->TID, ret->ThreadName, giFreeTickets);
 932         #endif
 933
 934         return ret;
 935 }
 936
 937 /**
 938  * \fn void Threads_SetFaultHandler(Uint Handler)
 939  * \brief Sets the signal handler for a signal
 940  */
 941 void Threads_SetFaultHandler(Uint Handler)
 942 {
 943         //Log_Debug("Threads", "Threads_SetFaultHandler: Handler = %p", Handler);
 944         Proc_GetCurThread()->FaultHandler = Handler;
 945 }
 946
 947 /**
 948  * \fn void Threads_Fault(int Num)
 949  * \brief Calls a fault handler
 950  */
 951 void Threads_Fault(int Num)
 952 {
 953         tThread *thread = Proc_GetCurThread();
 954
 955         if(!thread)     return ;
 956
 957         Log_Log("Threads", "Threads_Fault: thread->FaultHandler = %p", thread->FaultHandler);
 958
 959         switch(thread->FaultHandler)
 960         {
 961         case 0: // Panic?
 962                 Threads_Kill(thread, -1);
 963                 HALT();
 964                 return ;
 965         case 1: // Dump Core?
 966                 Threads_Kill(thread, -1);
 967                 HALT();
 968                 return ;
 969         }
 970
 971         // Double Fault? Oh, F**k
 972         if(thread->CurFaultNum != 0) {
 973                 Log_Warning("Threads", "Threads_Fault: Double fault on %i", thread->TID);
 974                 Threads_Kill(thread, -1);       // For now, just kill
 975                 HALT();
 976         }
 977
 978         thread->CurFaultNum = Num;
 979
 980         Proc_CallFaultHandler(thread);
 981 }
 982
 983 /**
 984  * \fn void Threads_SegFault(tVAddr Addr)
 985  * \brief Called when a Segment Fault occurs
 986  */
 987 void Threads_SegFault(tVAddr Addr)
 988 {
 989         tThread *cur = Proc_GetCurThread();
 990         cur->bInstrTrace = 0;
 991         Log_Warning("Threads", "Thread #%i committed a segfault at address %p", cur->TID, Addr);
 992         MM_DumpTables(0, USER_MAX);
 993         Threads_Fault( 1 );
 994         //Threads_Exit( 0, -1 );
 995 }
 996
 997 // --- Process Structure Access Functions ---
 998 tPID Threads_GetPID(void)
 999 {
1000         return Proc_GetCurThread()->TGID;
1001 }
1002 tTID Threads_GetTID(void)
1003 {
1004         return Proc_GetCurThread()->TID;
1005 }
1006 tUID Threads_GetUID(void)
1007 {
1008         return Proc_GetCurThread()->UID;
1009 }
1010 tGID Threads_GetGID(void)
1011 {
1012         return Proc_GetCurThread()->GID;
1013 }
1014
1015 int Threads_SetUID(Uint *Errno, tUID ID)
1016 {
1017         tThread *t = Proc_GetCurThread();
1018         if( t->UID != 0 ) {
1019                 *Errno = -EACCES;
1020                 return -1;
1021         }
1022         Log_Debug("Threads", "TID %i's UID set to %i", t->TID, ID);
1023         t->UID = ID;
1024         return 0;
1025 }
1026
1027 int Threads_SetGID(Uint *Errno, tGID ID)
1028 {
1029         tThread *t = Proc_GetCurThread();
1030         if( t->UID != 0 ) {
1031                 *Errno = -EACCES;
1032                 return -1;
1033         }
1034         Log_Debug("Threads", "TID %i's GID set to %i", t->TID, ID);
1035         t->GID = ID;
1036         return 0;
1037 }
1038
1039 /**
1040  * \fn void Threads_Dump(void)
1041  */
1042 void Threads_DumpActive(void)
1043 {
1044         tThread *thread;
1045         #if SCHEDULER_TYPE == SCHED_RR_PRI
1046          int    i;
1047         #endif
1048
1049         Log("Active Threads: (%i reported)", giNumActiveThreads);
1050
1051         #if SCHEDULER_TYPE == SCHED_RR_PRI
1052         for( i = 0; i < MIN_PRIORITY+1; i++ )
1053         {
1054                 for(thread=gaActiveThreads[i];thread;thread=thread->Next)
1055         #else
1056                 for(thread=gActiveThreads;thread;thread=thread->Next)
1057         #endif
1058                 {
1059                         Log(" %p %i (%i) - %s (CPU %i)",
1060                                 thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
1061                         if(thread->Status != THREAD_STAT_ACTIVE)
1062                                 Log("  ERROR State (%i) != THREAD_STAT_ACTIVE (%i)", thread->Status, THREAD_STAT_ACTIVE);
1063                         Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
1064                         Log("  KStack 0x%x", thread->KernelStack);
1065                         if( thread->bInstrTrace )
1066                                 Log("  Tracing Enabled");
1067                         Proc_DumpThreadCPUState(thread);
1068                 }
1069
1070         #if SCHEDULER_TYPE == SCHED_RR_PRI
1071         }
1072         #endif
1073 }
1074
1075 /**
1076  * \fn void Threads_Dump(void)
1077  * \brief Dumps a list of currently running threads
1078  */
1079 void Threads_Dump(void)
1080 {
1081         tThread *thread;
1082
1083         Log("--- Thread Dump ---");
1084         Threads_DumpActive();
1085
1086         Log("All Threads:");
1087         for(thread=gAllThreads;thread;thread=thread->GlobalNext)
1088         {
1089                 Log(" %p %i (%i) - %s (CPU %i)",
1090                         thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
1091                 Log("  State %i (%s)", thread->Status, casTHREAD_STAT[thread->Status]);
1092                 switch(thread->Status)
1093                 {
1094                 case THREAD_STAT_MUTEXSLEEP:
1095                         Log("  Mutex Pointer: %p", thread->WaitPointer);
1096                         break;
1097                 case THREAD_STAT_SEMAPHORESLEEP:
1098                         Log("  Semaphore Pointer: %p", thread->WaitPointer);
1099                         Log("  Semaphore Name: %s:%s",
1100                                 ((tSemaphore*)thread->WaitPointer)->ModName,
1101                                 ((tSemaphore*)thread->WaitPointer)->Name
1102                                 );
1103                         break;
1104                 case THREAD_STAT_ZOMBIE:
1105                         Log("  Return Status: %i", thread->RetStatus);
1106                         break;
1107                 default:        break;
1108                 }
1109                 Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
1110                 Log("  KStack 0x%x", thread->KernelStack);
1111                 if( thread->bInstrTrace )
1112                         Log("  Tracing Enabled");
1113                 Proc_DumpThreadCPUState(thread);
1114         }
1115 }
1116
1117 /**
1118  * \brief Gets the next thread to run
1119  * \param CPU   Current CPU
1120  * \param Last  The thread the CPU was running
1121  */
1122 tThread *Threads_GetNextToRun(int CPU, tThread *Last)
1123 {
1124         tThread *thread;
1125
1126         // If this CPU has the lock, we must let it complete
1127         if( CPU_HAS_LOCK( &glThreadListLock ) )
1128                 return Last;
1129
1130         // Don't change threads if the current CPU has switches disabled
1131         if( gaThreads_NoTaskSwitch[CPU] )
1132                 return Last;
1133
1134         // Lock thread list
1135         SHORTLOCK( &glThreadListLock );
1136
1137         // Clear Delete Queue
1138         // - I should probably put this in a worker thread to avoid calling free() in the scheduler
1139         //   DEFINITELY - free() can deadlock in this case
1140         //   I'll do it when it becomes an issue
1141         while(gDeleteThreads)
1142         {
1143                 thread = gDeleteThreads->Next;
1144                 // Only free if structure is unused
1145                 if( !IS_LOCKED(&gDeleteThreads->IsLocked) )
1146                 {
1147                         // Set to dead
1148                         gDeleteThreads->Status = THREAD_STAT_BURIED;
1149                         // Free name
1150                         if( IsHeap(gDeleteThreads->ThreadName) )
1151                                 free(gDeleteThreads->ThreadName);
1152                         // Remove from global list
1153                         if( gDeleteThreads == gAllThreads )
1154                                 gAllThreads = gDeleteThreads->GlobalNext;
1155                         else
1156                                 gDeleteThreads->GlobalPrev->GlobalNext = gDeleteThreads->GlobalNext;
1157                         free( gDeleteThreads );
1158                 }
1159                 gDeleteThreads = thread;
1160         }
1161
1162         // Make sure the current (well, old) thread is marked as de-scheduled
1163         if(Last)        Last->CurCPU = -1;
1164
1165         // No active threads, just take a nap
1166         if(giNumActiveThreads == 0) {
1167                 SHORTREL( &glThreadListLock );
1168                 #if DEBUG_TRACE_TICKETS
1169                 Log("No active threads");
1170                 #endif
1171                 return NULL;
1172         }
1173
1174         #if SCHEDULER_TYPE != SCHED_RR_PRI
1175         // Special case: 1 thread
1176         if(giNumActiveThreads == 1) {
1177                 if( gActiveThreads->CurCPU == -1 )
1178                         gActiveThreads->CurCPU = CPU;
1179
1180                 SHORTREL( &glThreadListLock );
1181
1182                 if( gActiveThreads->CurCPU == CPU )
1183                         return gActiveThreads;
1184
1185                 return NULL;    // CPU has nothing to do
1186         }
1187         #endif
1188
1189         // Allow the old thread to be scheduled again
1190         if( Last ) {
1191                 if( Last->Status == THREAD_STAT_ACTIVE ) {
1192                         #if SCHEDULER_TYPE == SCHED_LOTTERY
1193                         giFreeTickets += caiTICKET_COUNTS[ Last->Priority ];
1194                         # if DEBUG_TRACE_TICKETS
1195                         LogF("Log: CPU%i released %p (%i %s) into the pool (%i [+%i] tickets in pool)\n",
1196                                 CPU, Last, Last->TID, Last->ThreadName, giFreeTickets,
1197                                 caiTICKET_COUNTS[ Last->Priority ]);
1198                         # endif
1199                         #endif
1200                 }
1201                 #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
1202                 else
1203                         LogF("Log: CPU%i released %p (%i %s)->Status = %i (Released,not in pool)\n",
1204                                 CPU, Last, Last->TID, Last->ThreadName, Last->Status);
1205                 #endif
1206                 Last->CurCPU = -1;
1207         }
1208
1209         // ---
1210         // Lottery Scheduler
1211         // ---
1212         #if SCHEDULER_TYPE == SCHED_LOTTERY
1213         {
1214                  int    ticket, number;
1215                 # if 1
1216                 number = 0;
1217                 for(thread = gActiveThreads; thread; thread = thread->Next) {
1218                         if(thread->CurCPU >= 0) continue;
1219                         if(thread->Status != THREAD_STAT_ACTIVE)
1220                                 Panic("Bookkeeping fail - %p %i(%s) is on the active queue with a status of %i",
1221                                         thread, thread->TID, thread->ThreadName, thread->Status);
1222                         if(thread->Next == thread) {
1223                                 Panic("Bookkeeping fail - %p %i(%s) loops back on itself",
1224                                         thread, thread->TID, thread->ThreadName, thread->Status);
1225                         }
1226                         number += caiTICKET_COUNTS[ thread->Priority ];
1227                 }
1228                 if(number != giFreeTickets) {
1229                         Panic("Bookkeeping fail (giFreeTickets(%i) != number(%i)) - CPU%i",
1230                                 giFreeTickets, number, CPU);
1231                 }
1232                 # endif
1233
1234                 // No free tickets (all tasks delegated to cores)
1235                 if( giFreeTickets == 0 ) {
1236                         SHORTREL(&glThreadListLock);
1237                         return NULL;
1238                 }
1239
1240                 // Get the ticket number
1241                 ticket = number = rand() % giFreeTickets;
1242
1243                 // Find the next thread
1244                 for(thread=gActiveThreads;thread;thread=thread->Next)
1245                 {
1246                         if(thread->CurCPU >= 0) continue;
1247                         if( caiTICKET_COUNTS[ thread->Priority ] > number)      break;
1248                         number -= caiTICKET_COUNTS[ thread->Priority ];
1249                 }
1250
1251                 // If we didn't find a thread, something went wrong
1252                 if(thread == NULL)
1253                 {
1254                         number = 0;
1255                         for(thread=gActiveThreads;thread;thread=thread->Next) {
1256                                 if(thread->CurCPU >= 0) continue;
1257                                 number += caiTICKET_COUNTS[ thread->Priority ];
1258                         }
1259                         Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)",
1260                                 giFreeTickets, number);
1261                 }
1262
1263                 giFreeTickets -= caiTICKET_COUNTS[ thread->Priority ];
1264                 # if DEBUG_TRACE_TICKETS
1265                 LogF("Log: CPU%i allocated %p (%i %s), (%i [-%i] tickets in pool), \n",
1266                         CPU, thread, thread->TID, thread->ThreadName,
1267                         giFreeTickets, caiTICKET_COUNTS[ thread->Priority ]);
1268                 # endif
1269         }
1270
1271         // ---
1272         // Priority based round robin scheduler
1273         // ---
1274         #elif SCHEDULER_TYPE == SCHED_RR_PRI
1275         {
1276                  int    i;
1277                 for( i = 0; i < MIN_PRIORITY + 1; i ++ )
1278                 {
1279                         for(thread = gaActiveThreads[i]; thread; thread = thread->Next)
1280                         {
1281                                 if( thread->CurCPU == -1 )      break;
1282                         }
1283                         // If we fall onto the same queue again, special handling is
1284                         // needed
1285                         if( Last && Last->Status == THREAD_STAT_ACTIVE && i == Last->Priority ) {
1286                                 tThread *savedThread = thread;
1287
1288                                 // Find the next unscheduled thread in the list
1289                                 for( thread = Last->Next; thread; thread = thread->Next )
1290                                 {
1291                                         if( thread->CurCPU == -1 )      break;
1292                                 }
1293                                 // If we don't find anything after, just use the one
1294                                 // found above.
1295                                 if( !thread )   thread = savedThread;
1296                         }
1297                         // Found a thread? Schedule it!
1298                         if( thread )    break;
1299                 }
1300
1301                 // Anything to do?
1302                 if( !thread ) {
1303                         SHORTREL(&glThreadListLock);
1304                         return NULL;
1305                 }
1306                 if( thread->Status != THREAD_STAT_ACTIVE ) {
1307                         LogF("Oops, Thread %i (%s) is not active\n", thread->TID, thread->ThreadName);
1308                 }
1309         }
1310         #elif SCHEDULER_TYPE == SCHED_RR_SIM
1311         {
1312                 // Find the next unscheduled thread in the list
1313                 for( thread = Last->Next; thread; thread = thread->Next )
1314                 {
1315                         if( thread->CurCPU == -1 )      break;
1316                 }
1317                 // If we don't find anything after, search from the beginning
1318                 if( !thread )
1319                 {
1320                         for(thread = gActiveThreads; thread; thread = thread->Next)
1321                         {
1322                                 if( thread->CurCPU == -1 )      break;
1323                         }
1324                 }
1325
1326                 // Anything to do?
1327                 if( !thread ) {
1328                         SHORTREL(&glThreadListLock);
1329                         return NULL;
1330                 }
1331         }
1332         #else
1333         # error "Unimplemented scheduling algorithm"
1334         #endif
1335
1336         // Make the new thread non-schedulable
1337         thread->CurCPU = CPU;
1338         thread->Remaining = thread->Quantum;
1339
1340         SHORTREL( &glThreadListLock );
1341
1342         return thread;
1343 }
1344
1345 // Acquire mutex (see mutex.h for documentation)
1346 int Mutex_Acquire(tMutex *Mutex)
1347 {
1348         tThread *us = Proc_GetCurThread();
1349
1350         // Get protector
1351         SHORTLOCK( &Mutex->Protector );
1352
1353         //Log("Mutex_Acquire: (%p)", Mutex);
1354
1355         // Check if the lock is already held
1356         if( Mutex->Owner ) {
1357                 SHORTLOCK( &glThreadListLock );
1358                 // - Remove from active list
1359                 us = Threads_RemActive();
1360                 us->Next = NULL;
1361                 // - Mark as sleeping
1362                 us->Status = THREAD_STAT_MUTEXSLEEP;
1363                 us->WaitPointer = Mutex;
1364
1365                 // - Add to waiting
1366                 if(Mutex->LastWaiting) {
1367                         Mutex->LastWaiting->Next = us;
1368                         Mutex->LastWaiting = us;
1369                 }
1370                 else {
1371                         Mutex->Waiting = us;
1372                         Mutex->LastWaiting = us;
1373                 }
1374
1375                 #if DEBUG_TRACE_STATE
1376                 Log("%p (%i %s) waiting on mutex %p",
1377                         us, us->TID, us->ThreadName, Mutex);
1378                 #endif
1379
1380                 #if 0
1381                 {
1382                          int    i = 0;
1383                         tThread *t;
1384                         for( t = Mutex->Waiting; t; t = t->Next, i++ )
1385                                 Log("[%i] (tMutex)%p->Waiting[%i] = %p (%i %s)", us->TID, Mutex, i,
1386                                         t, t->TID, t->ThreadName);
1387                 }
1388                 #endif
1389
1390                 SHORTREL( &glThreadListLock );
1391                 SHORTREL( &Mutex->Protector );
1392                 while(us->Status == THREAD_STAT_MUTEXSLEEP)     Threads_Yield();
1393                 // We're only woken when we get the lock
1394                 us->WaitPointer = NULL;
1395         }
1396         // Ooh, let's take it!
1397         else {
1398                 Mutex->Owner = us;
1399                 SHORTREL( &Mutex->Protector );
1400         }
1401
1402         #if 0
1403         extern tMutex   glPhysAlloc;
1404         if( Mutex != &glPhysAlloc )
1405                 LogF("Mutex %p taken by %i %p\n", Mutex, us->TID, __builtin_return_address(0));
1406         #endif
1407
1408         return 0;
1409 }
1410
1411 // Release a mutex
1412 void Mutex_Release(tMutex *Mutex)
1413 {
1414         SHORTLOCK( &Mutex->Protector );
1415         //Log("Mutex_Release: (%p)", Mutex);
1416         if( Mutex->Waiting ) {
1417                 Mutex->Owner = Mutex->Waiting;  // Set owner
1418                 Mutex->Waiting = Mutex->Waiting->Next;  // Next!
1419                 // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
1420                 // 2010-10-02 21:50 - Comemerating the death of the longest single
1421                 //                    blocker in the Acess2 history. REMEMBER TO
1422                 //                    FUCKING MAINTAIN YOUR FUCKING LISTS DIPWIT
1423                 if( Mutex->LastWaiting == Mutex->Owner )
1424                         Mutex->LastWaiting = NULL;
1425
1426                 // Wake new owner
1427                 SHORTLOCK( &glThreadListLock );
1428                 if( Mutex->Owner->Status != THREAD_STAT_ACTIVE )
1429                         Threads_AddActive(Mutex->Owner);
1430                 SHORTREL( &glThreadListLock );
1431         }
1432         else {
1433                 Mutex->Owner = NULL;
1434         }
1435         SHORTREL( &Mutex->Protector );
1436
1437         #if 0
1438         extern tMutex   glPhysAlloc;
1439         if( Mutex != &glPhysAlloc )
1440                 LogF("Mutex %p released by %i %p\n", Mutex, Threads_GetTID(), __builtin_return_address(0));
1441         #endif
1442 }
1443
1444 // Check if a mutex is locked
1445 int Mutex_IsLocked(tMutex *Mutex)
1446 {
1447         return Mutex->Owner != NULL;
1448 }
1449
1450 //
1451 // Initialise a semaphore
1452 //
1453 void Semaphore_Init(tSemaphore *Sem, int Value, int MaxValue, const char *Module, const char *Name)
1454 {
1455         memset(Sem, 0, sizeof(tSemaphore));
1456         Sem->Value = Value;
1457         Sem->ModName = Module;
1458         Sem->Name = Name;
1459         Sem->MaxValue = MaxValue;
1460 }
1461 //
1462 // Wait for items to be avaliable
1463 //
1464 int Semaphore_Wait(tSemaphore *Sem, int MaxToTake)
1465 {
1466         tThread *us;
1467          int    taken;
1468         if( MaxToTake < 0 ) {
1469                 Log_Warning("Threads", "Semaphore_Wait: User bug - MaxToTake(%i) < 0, Sem=%p(%s)",
1470                         MaxToTake, Sem, Sem->Name);
1471         }
1472
1473         SHORTLOCK( &Sem->Protector );
1474
1475         // Check if there's already items avaliable
1476         if( Sem->Value > 0 ) {
1477                 // Take what we need
1478                 if( MaxToTake && Sem->Value > MaxToTake )
1479                         taken = MaxToTake;
1480                 else
1481                         taken = Sem->Value;
1482                 Sem->Value -= taken;
1483         }
1484         else
1485         {
1486                 SHORTLOCK( &glThreadListLock );
1487
1488                 // - Remove from active list
1489                 us = Threads_RemActive();
1490                 us->Next = NULL;
1491                 // - Mark as sleeping
1492                 us->Status = THREAD_STAT_SEMAPHORESLEEP;
1493                 us->WaitPointer = Sem;
1494                 us->RetStatus = MaxToTake;      // Use RetStatus as a temp variable
1495
1496                 // - Add to waiting
1497                 if(Sem->LastWaiting) {
1498                         Sem->LastWaiting->Next = us;
1499                         Sem->LastWaiting = us;
1500                 }
1501                 else {
1502                         Sem->Waiting = us;
1503                         Sem->LastWaiting = us;
1504                 }
1505
1506                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1507                 Log("%p (%i %s) waiting on semaphore %p %s:%s",
1508                         us, us->TID, us->ThreadName,
1509                         Sem, Sem->ModName, Sem->Name);
1510                 #endif
1511
1512                 SHORTREL( &Sem->Protector );    // Release first to make sure it is released
1513                 SHORTREL( &glThreadListLock );
1514                 while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
1515                 // We're only woken when there's something avaliable (or a signal arrives)
1516                 us->WaitPointer = NULL;
1517
1518                 taken = us->RetStatus;
1519
1520                 // Get the lock again
1521                 SHORTLOCK( &Sem->Protector );
1522         }
1523
1524         // While there is space, and there are thread waiting
1525         // wake the first thread and give it what it wants (or what's left)
1526         while( (Sem->MaxValue == 0 || Sem->Value < Sem->MaxValue) && Sem->Signaling )
1527         {
1528                  int    given;
1529                 tThread *toWake = Sem->Signaling;
1530
1531                 Sem->Signaling = Sem->Signaling->Next;
1532                 // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
1533                 if( Sem->Signaling == NULL )
1534                         Sem->LastSignaling = NULL;
1535
1536                 // Figure out how much to give
1537                 if( toWake->RetStatus && Sem->Value + toWake->RetStatus < Sem->MaxValue )
1538                         given = toWake->RetStatus;
1539                 else
1540                         given = Sem->MaxValue - Sem->Value;
1541                 Sem->Value -= given;
1542
1543
1544                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1545                 Log("%p (%i %s) woken by wait on %p %s:%s",
1546                         toWake, toWake->TID, toWake->ThreadName,
1547                         Sem, Sem->ModName, Sem->Name);
1548                 #endif
1549
1550                 // Save the number we gave to the thread's status
1551                 toWake->RetStatus = given;
1552
1553                 // Wake the sleeper
1554                 SHORTLOCK( &glThreadListLock );
1555                 if( toWake->Status != THREAD_STAT_ACTIVE )
1556                         Threads_AddActive(toWake);
1557                 SHORTREL( &glThreadListLock );
1558         }
1559         SHORTREL( &Sem->Protector );
1560
1561         return taken;
1562 }
1563
1564 //
1565 // Add items to a semaphore
1566 //
1567 int Semaphore_Signal(tSemaphore *Sem, int AmmountToAdd)
1568 {
1569          int    given;
1570          int    added;
1571
1572         if( AmmountToAdd < 0 ) {
1573                 Log_Warning("Threads", "Semaphore_Signal: User bug - AmmountToAdd(%i) < 0, Sem=%p(%s)",
1574                         AmmountToAdd, Sem, Sem->Name);
1575         }
1576         SHORTLOCK( &Sem->Protector );
1577
1578         // Check if we have to block
1579         if( Sem->MaxValue && Sem->Value == Sem->MaxValue )
1580         {
1581                 tThread *us;
1582                 #if 0
1583                 Log_Debug("Threads", "Semaphore_Signal: IDLE Sem = %s:%s", Sem->ModName, Sem->Name);
1584                 Log_Debug("Threads", "Semaphore_Signal: Sem->Value(%i) == Sem->MaxValue(%i)", Sem->Value, Sem->MaxValue);
1585                 #endif
1586
1587                 SHORTLOCK( &glThreadListLock );
1588                 // - Remove from active list
1589                 us = Threads_RemActive();
1590                 us->Next = NULL;
1591                 // - Mark as sleeping
1592                 us->Status = THREAD_STAT_SEMAPHORESLEEP;
1593                 us->WaitPointer = Sem;
1594                 us->RetStatus = AmmountToAdd;   // Use RetStatus as a temp variable
1595
1596                 // - Add to waiting
1597                 if(Sem->LastSignaling) {
1598                         Sem->LastSignaling->Next = us;
1599                         Sem->LastSignaling = us;
1600                 }
1601                 else {
1602                         Sem->Signaling = us;
1603                         Sem->LastSignaling = us;
1604                 }
1605
1606                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1607                 Log("%p (%i %s) signaling semaphore %p %s:%s",
1608                         us, us->TID, us->ThreadName,
1609                         Sem, Sem->ModName, Sem->Name);
1610                 #endif
1611
1612                 SHORTREL( &glThreadListLock );
1613                 SHORTREL( &Sem->Protector );
1614                 while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
1615                 // We're only woken when there's something avaliable
1616                 us->WaitPointer = NULL;
1617
1618                 added = us->RetStatus;
1619
1620                 // Get the lock again
1621                 SHORTLOCK( &Sem->Protector );
1622         }
1623         // Non blocking
1624         else
1625         {
1626                 // Figure out how much we need to take off
1627                 if( Sem->MaxValue && Sem->Value + AmmountToAdd > Sem->MaxValue)
1628                         added = Sem->MaxValue - Sem->Value;
1629                 else
1630                         added = AmmountToAdd;
1631                 Sem->Value += added;
1632         }
1633
1634         // While there are items avaliable, and there are thread waiting
1635         // wake the first thread and give it what it wants (or what's left)
1636         while( Sem->Value && Sem->Waiting )
1637         {
1638                 tThread *toWake = Sem->Waiting;
1639
1640                 // Remove thread from list (double ended, so clear LastWaiting if needed)
1641                 Sem->Waiting = Sem->Waiting->Next;
1642                 if( Sem->Waiting == NULL )
1643                         Sem->LastWaiting = NULL;
1644
1645                 // Figure out how much to give to woken thread
1646                 // - Requested count is stored in ->RetStatus
1647                 if( toWake->RetStatus && Sem->Value > toWake->RetStatus )
1648                         given = toWake->RetStatus;
1649                 else
1650                         given = Sem->Value;
1651                 Sem->Value -= given;
1652
1653                 // Save the number we gave to the thread's status
1654                 toWake->RetStatus = given;
1655
1656                 if(toWake->bInstrTrace)
1657                         Log("%s(%i) given %i from %p", toWake->ThreadName, toWake->TID, given, Sem);
1658                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1659                 Log("%p (%i %s) woken by signal on %p %s:%s",
1660                         toWake, toWake->TID, toWake->ThreadName,
1661                         Sem, Sem->ModName, Sem->Name);
1662                 #endif
1663
1664                 // Wake the sleeper
1665                 SHORTLOCK( &glThreadListLock );
1666                 if( toWake->Status != THREAD_STAT_ACTIVE )
1667                         Threads_AddActive(toWake);
1668                 else
1669                         Warning("Thread %p (%i %s) is already awake", toWake, toWake->TID, toWake->ThreadName);
1670                 SHORTREL( &glThreadListLock );
1671         }
1672         SHORTREL( &Sem->Protector );
1673
1674         return added;
1675 }
1676
1677 //
1678 // Get the current value of a semaphore
1679 //
1680 int Semaphore_GetValue(tSemaphore *Sem)
1681 {
1682         return Sem->Value;
1683 }
1684
1685 // === EXPORTS ===
1686 EXPORT(Threads_GetUID);
1687 EXPORT(Threads_GetGID);
1688 EXPORT(Mutex_Acquire);
1689 EXPORT(Mutex_Release);
1690 EXPORT(Mutex_IsLocked);
1691 EXPORT(Semaphore_Init);
1692 EXPORT(Semaphore_Wait);
1693 EXPORT(Semaphore_Signal);