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                 SHORTREL( &glThreadListLock );
 644         } else {
 645                 Thread->Status = THREAD_STAT_ZOMBIE;
 646                 SHORTREL( &glThreadListLock );
 647                 // Wake parent
 648                 Threads_Wake( Thread->Parent );
 649         }
 650
 651         Log("Thread %i went *hurk* (%i)", Thread->TID, Status);
 652
 653         // Release spinlocks
 654         SHORTREL( &Thread->IsLocked );  // TODO: We may not actually be released...
 655
 656         // And, reschedule
 657         if(isCurThread)
 658         {
 659                 for( ;; )
 660                         Proc_Reschedule();
 661         }
 662 }
 663
 664 /**
 665  * \brief Yield remainder of the current thread's timeslice
 666  */
 667 void Threads_Yield(void)
 668 {
 669 //      Log("Threads_Yield: by %p", __builtin_return_address(0));
 670         Proc_Reschedule();
 671 }
 672
 673 /**
 674  * \fn void Threads_Sleep(void)
 675  * \brief Take the current process off the run queue
 676  */
 677 void Threads_Sleep(void)
 678 {
 679         tThread *cur = Proc_GetCurThread();
 680
 681         // Acquire Spinlock
 682         SHORTLOCK( &glThreadListLock );
 683
 684         // Don't sleep if there is a message waiting
 685         if( cur->Messages ) {
 686                 SHORTREL( &glThreadListLock );
 687                 return;
 688         }
 689
 690         // Remove us from running queue
 691         Threads_RemActive();
 692         // Mark thread as sleeping
 693         cur->Status = THREAD_STAT_SLEEPING;
 694
 695         // Add to Sleeping List (at the top)
 696         cur->Next = gSleepingThreads;
 697         gSleepingThreads = cur;
 698
 699
 700         #if DEBUG_TRACE_STATE
 701         Log("Threads_Sleep: %p (%i %s) sleeping", cur, cur->TID, cur->ThreadName);
 702         #endif
 703
 704         // Release Spinlock
 705         SHORTREL( &glThreadListLock );
 706
 707         while(cur->Status != THREAD_STAT_ACTIVE) {
 708                 Proc_Reschedule();
 709                 if( cur->Status != THREAD_STAT_ACTIVE )
 710                         Log("%i - Huh? why am I up? zzzz...", cur->TID);
 711         }
 712 }
 713
 714
 715 /**
 716  * \fn int Threads_Wake( tThread *Thread )
 717  * \brief Wakes a sleeping/waiting thread up
 718  * \param Thread        Thread to wake
 719  * \return Boolean Failure (Returns ERRNO)
 720  * \warning This should ONLY be called with task switches disabled
 721  */
 722 int Threads_Wake(tThread *Thread)
 723 {
 724         if(!Thread)
 725                 return -EINVAL;
 726
 727         switch(Thread->Status)
 728         {
 729         case THREAD_STAT_ACTIVE:
 730                 Log("Threads_Wake - Waking awake thread (%i)", Thread->TID);
 731                 return -EALREADY;
 732
 733         case THREAD_STAT_SLEEPING:
 734                 SHORTLOCK( &glThreadListLock );
 735                 // Remove from sleeping queue
 736                 Threads_int_DelFromQueue(&gSleepingThreads, Thread);
 737
 738                 SHORTREL( &glThreadListLock );
 739                 Threads_AddActive( Thread );
 740
 741                 #if DEBUG_TRACE_STATE
 742                 Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName);
 743                 #endif
 744                 return -EOK;
 745
 746         case THREAD_STAT_SEMAPHORESLEEP: {
 747                 tSemaphore      *sem;
 748                 tThread *th, *prev=NULL;
 749
 750                 sem = Thread->WaitPointer;
 751
 752                 SHORTLOCK( &sem->Protector );
 753
 754                 // Remove from sleeping queue
 755                 for( th = sem->Waiting; th; prev = th, th = th->Next )
 756                         if( th == Thread )      break;
 757                 if( th )
 758                 {
 759                         if(prev)
 760                                 prev->Next = Thread->Next;
 761                         else
 762                                 sem->Waiting = Thread->Next;
 763                         if(sem->LastWaiting == Thread)
 764                                 sem->LastWaiting = prev;
 765                 }
 766                 else
 767                 {
 768                         prev = NULL;
 769                         for( th = sem->Signaling; th; prev = th, th = th->Next )
 770                                 if( th == Thread )      break;
 771                         if( !th ) {
 772                                 Log_Warning("Threads", "Thread %p(%i %s) is not on semaphore %p(%s:%s)",
 773                                         Thread, Thread->TID, Thread->ThreadName,
 774                                         sem, sem->ModName, sem->Name);
 775                                 return -EINTERNAL;
 776                         }
 777
 778                         if(prev)
 779                                 prev->Next = Thread->Next;
 780                         else
 781                                 sem->Signaling = Thread->Next;
 782                         if(sem->LastSignaling == Thread)
 783                                 sem->LastSignaling = prev;
 784                 }
 785
 786                 Threads_AddActive( Thread );
 787
 788                 #if DEBUG_TRACE_STATE
 789                 Log("Threads_Sleep: %p(%i %s) woken from semaphore", Thread, Thread->TID, Thread->ThreadName);
 790                 #endif
 791                 SHORTREL( &sem->Protector );
 792                 } return -EOK;
 793
 794         case THREAD_STAT_WAITING:
 795                 Warning("Threads_Wake - Waiting threads are not currently supported");
 796                 return -ENOTIMPL;
 797
 798         case THREAD_STAT_DEAD:
 799                 Warning("Threads_Wake - Attempt to wake dead thread (%i)", Thread->TID);
 800                 return -ENOTIMPL;
 801
 802         default:
 803                 Warning("Threads_Wake - Unknown process status (%i)\n", Thread->Status);
 804                 return -EINTERNAL;
 805         }
 806 }
 807
 808 /**
 809  * \brief Wake a thread given the TID
 810  * \param TID   Thread ID to wake
 811  * \return Boolean Faulure (errno)
 812  */
 813 int Threads_WakeTID(tTID TID)
 814 {
 815         tThread *thread = Threads_GetThread(TID);
 816          int    ret;
 817         if(!thread)
 818                 return -ENOENT;
 819         ret = Threads_Wake( thread );
 820         //Log_Debug("Threads", "TID %i woke %i (%p)", Threads_GetTID(), TID, thread);
 821         return ret;
 822 }
 823
 824 void Threads_ToggleTrace(int TID)
 825 {
 826         tThread *thread = Threads_GetThread(TID);
 827         if(!thread)     return ;
 828         thread->bInstrTrace = !thread->bInstrTrace;
 829 }
 830
 831 /**
 832  * \brief Adds a thread to the active queue
 833  */
 834 void Threads_AddActive(tThread *Thread)
 835 {
 836         SHORTLOCK( &glThreadListLock );
 837
 838         if( Thread->Status == THREAD_STAT_ACTIVE ) {
 839                 tThread *cur = Proc_GetCurThread();
 840                 Log_Warning("Threads", "WTF, %p CPU%i %p (%i %s) is adding %p (%i %s) when it is active",
 841                         __builtin_return_address(0),
 842                         GetCPUNum(), cur, cur->TID, cur->ThreadName, Thread, Thread->TID, Thread->ThreadName);
 843                 SHORTREL( &glThreadListLock );
 844                 return ;
 845         }
 846
 847         // Set state
 848         Thread->Status = THREAD_STAT_ACTIVE;
 849 //      Thread->CurCPU = -1;
 850         // Add to active list
 851         {
 852                 tThread *tmp, *prev = NULL;
 853                 #if SCHEDULER_TYPE == SCHED_RR_PRI
 854                 for( tmp = gaActiveThreads[Thread->Priority]; tmp; prev = tmp, tmp = tmp->Next );
 855                 if(prev)
 856                         prev->Next = Thread;
 857                 else
 858                         gaActiveThreads[Thread->Priority] = Thread;
 859                 #else
 860                 for( tmp = gActiveThreads; tmp; prev = tmp, tmp = tmp->Next );
 861                 if(prev)
 862                         prev->Next = Thread;
 863                 else
 864                         gActiveThreads = Thread;
 865                 #endif
 866                 Thread->Next = NULL;
 867         }
 868
 869         // Update bookkeeping
 870         giNumActiveThreads ++;
 871
 872         #if SCHEDULER_TYPE == SCHED_LOTTERY
 873         {
 874                  int    delta;
 875                 // Only change the ticket count if the thread is un-scheduled
 876                 if(Thread->CurCPU != -1)
 877                         delta = 0;
 878                 else
 879                         delta = caiTICKET_COUNTS[ Thread->Priority ];
 880
 881                 giFreeTickets += delta;
 882                 # if DEBUG_TRACE_TICKETS
 883                 Log("CPU%i %p (%i %s) added, new giFreeTickets = %i [+%i]",
 884                         GetCPUNum(), Thread, Thread->TID, Thread->ThreadName,
 885                         giFreeTickets, delta
 886                         );
 887                 # endif
 888         }
 889         #endif
 890
 891         SHORTREL( &glThreadListLock );
 892 }
 893
 894 /**
 895  * \brief Removes the current thread from the active queue
 896  * \warning This should ONLY be called with the lock held
 897  * \return Current thread pointer
 898  */
 899 tThread *Threads_RemActive(void)
 900 {
 901         tThread *ret = Proc_GetCurThread();
 902
 903         if( !IS_LOCKED(&glThreadListLock) ) {
 904                 Log_KernelPanic("Threads", "Threads_RemActive called without lock held");
 905                 return NULL;
 906         }
 907
 908         // Delete from active queue
 909         #if SCHEDULER_TYPE == SCHED_RR_PRI
 910         if( !Threads_int_DelFromQueue(&gaActiveThreads[ret->Priority], ret) )
 911         #else
 912         if( !Threads_int_DelFromQueue(&gActiveThreads, ret) )
 913         #endif
 914         {
 915                 SHORTREL( &glThreadListLock );
 916                 Log_Warning("Threads", "Current thread %p(%i %s) is not on active queue",
 917                         ret, ret->TID, ret->ThreadName
 918                         );
 919                 return NULL;
 920         }
 921
 922         ret->Next = NULL;
 923         ret->Remaining = 0;
 924
 925         giNumActiveThreads --;
 926         // no need to decrement tickets, scheduler did it for us
 927
 928         #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
 929         Log("CPU%i %p (%i %s) removed, giFreeTickets = %i [nc]",
 930                 GetCPUNum(), ret, ret->TID, ret->ThreadName, giFreeTickets);
 931         #endif
 932
 933         return ret;
 934 }
 935
 936 /**
 937  * \fn void Threads_SetFaultHandler(Uint Handler)
 938  * \brief Sets the signal handler for a signal
 939  */
 940 void Threads_SetFaultHandler(Uint Handler)
 941 {
 942         //Log_Debug("Threads", "Threads_SetFaultHandler: Handler = %p", Handler);
 943         Proc_GetCurThread()->FaultHandler = Handler;
 944 }
 945
 946 /**
 947  * \fn void Threads_Fault(int Num)
 948  * \brief Calls a fault handler
 949  */
 950 void Threads_Fault(int Num)
 951 {
 952         tThread *thread = Proc_GetCurThread();
 953
 954         if(!thread)     return ;
 955
 956         Log_Log("Threads", "Threads_Fault: thread->FaultHandler = %p", thread->FaultHandler);
 957
 958         switch(thread->FaultHandler)
 959         {
 960         case 0: // Panic?
 961                 Threads_Kill(thread, -1);
 962                 HALT();
 963                 return ;
 964         case 1: // Dump Core?
 965                 Threads_Kill(thread, -1);
 966                 HALT();
 967                 return ;
 968         }
 969
 970         // Double Fault? Oh, F**k
 971         if(thread->CurFaultNum != 0) {
 972                 Log_Warning("Threads", "Threads_Fault: Double fault on %i", thread->TID);
 973                 Threads_Kill(thread, -1);       // For now, just kill
 974                 HALT();
 975         }
 976
 977         thread->CurFaultNum = Num;
 978
 979         Proc_CallFaultHandler(thread);
 980 }
 981
 982 /**
 983  * \fn void Threads_SegFault(tVAddr Addr)
 984  * \brief Called when a Segment Fault occurs
 985  */
 986 void Threads_SegFault(tVAddr Addr)
 987 {
 988         tThread *cur = Proc_GetCurThread();
 989         cur->bInstrTrace = 0;
 990         Log_Warning("Threads", "Thread #%i committed a segfault at address %p", cur->TID, Addr);
 991         MM_DumpTables(0, USER_MAX);
 992         Threads_Fault( 1 );
 993         //Threads_Exit( 0, -1 );
 994 }
 995
 996 // --- Process Structure Access Functions ---
 997 tPID Threads_GetPID(void)
 998 {
 999         return Proc_GetCurThread()->TGID;
1000 }
1001 tTID Threads_GetTID(void)
1002 {
1003         return Proc_GetCurThread()->TID;
1004 }
1005 tUID Threads_GetUID(void)
1006 {
1007         return Proc_GetCurThread()->UID;
1008 }
1009 tGID Threads_GetGID(void)
1010 {
1011         return Proc_GetCurThread()->GID;
1012 }
1013
1014 int Threads_SetUID(Uint *Errno, tUID ID)
1015 {
1016         tThread *t = Proc_GetCurThread();
1017         if( t->UID != 0 ) {
1018                 *Errno = -EACCES;
1019                 return -1;
1020         }
1021         Log_Debug("Threads", "TID %i's UID set to %i", t->TID, ID);
1022         t->UID = ID;
1023         return 0;
1024 }
1025
1026 int Threads_SetGID(Uint *Errno, tGID ID)
1027 {
1028         tThread *t = Proc_GetCurThread();
1029         if( t->UID != 0 ) {
1030                 *Errno = -EACCES;
1031                 return -1;
1032         }
1033         Log_Debug("Threads", "TID %i's GID set to %i", t->TID, ID);
1034         t->GID = ID;
1035         return 0;
1036 }
1037
1038 /**
1039  * \fn void Threads_Dump(void)
1040  */
1041 void Threads_DumpActive(void)
1042 {
1043         tThread *thread;
1044         #if SCHEDULER_TYPE == SCHED_RR_PRI
1045          int    i;
1046         #endif
1047
1048         Log("Active Threads: (%i reported)", giNumActiveThreads);
1049
1050         #if SCHEDULER_TYPE == SCHED_RR_PRI
1051         for( i = 0; i < MIN_PRIORITY+1; i++ )
1052         {
1053                 for(thread=gaActiveThreads[i];thread;thread=thread->Next)
1054         #else
1055                 for(thread=gActiveThreads;thread;thread=thread->Next)
1056         #endif
1057                 {
1058                         Log(" %p %i (%i) - %s (CPU %i)",
1059                                 thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
1060                         if(thread->Status != THREAD_STAT_ACTIVE)
1061                                 Log("  ERROR State (%i) != THREAD_STAT_ACTIVE (%i)", thread->Status, THREAD_STAT_ACTIVE);
1062                         Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
1063                         Log("  KStack 0x%x", thread->KernelStack);
1064                         if( thread->bInstrTrace )
1065                                 Log("  Tracing Enabled");
1066                         Proc_DumpThreadCPUState(thread);
1067                 }
1068
1069         #if SCHEDULER_TYPE == SCHED_RR_PRI
1070         }
1071         #endif
1072 }
1073
1074 /**
1075  * \fn void Threads_Dump(void)
1076  * \brief Dumps a list of currently running threads
1077  */
1078 void Threads_Dump(void)
1079 {
1080         tThread *thread;
1081
1082         Log("--- Thread Dump ---");
1083         Threads_DumpActive();
1084
1085         Log("All Threads:");
1086         for(thread=gAllThreads;thread;thread=thread->GlobalNext)
1087         {
1088                 Log(" %p %i (%i) - %s (CPU %i)",
1089                         thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
1090                 Log("  State %i (%s)", thread->Status, casTHREAD_STAT[thread->Status]);
1091                 switch(thread->Status)
1092                 {
1093                 case THREAD_STAT_MUTEXSLEEP:
1094                         Log("  Mutex Pointer: %p", thread->WaitPointer);
1095                         break;
1096                 case THREAD_STAT_SEMAPHORESLEEP:
1097                         Log("  Semaphore Pointer: %p", thread->WaitPointer);
1098                         Log("  Semaphore Name: %s:%s",
1099                                 ((tSemaphore*)thread->WaitPointer)->ModName,
1100                                 ((tSemaphore*)thread->WaitPointer)->Name
1101                                 );
1102                         break;
1103                 case THREAD_STAT_ZOMBIE:
1104                         Log("  Return Status: %i", thread->RetStatus);
1105                         break;
1106                 default:        break;
1107                 }
1108                 Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
1109                 Log("  KStack 0x%x", thread->KernelStack);
1110                 if( thread->bInstrTrace )
1111                         Log("  Tracing Enabled");
1112                 Proc_DumpThreadCPUState(thread);
1113         }
1114 }
1115
1116 /**
1117  * \brief Gets the next thread to run
1118  * \param CPU   Current CPU
1119  * \param Last  The thread the CPU was running
1120  */
1121 tThread *Threads_GetNextToRun(int CPU, tThread *Last)
1122 {
1123         tThread *thread;
1124
1125         // If this CPU has the lock, we must let it complete
1126         if( CPU_HAS_LOCK( &glThreadListLock ) )
1127                 return Last;
1128
1129         // Don't change threads if the current CPU has switches disabled
1130         if( gaThreads_NoTaskSwitch[CPU] )
1131                 return Last;
1132
1133         // Lock thread list
1134         SHORTLOCK( &glThreadListLock );
1135
1136         // Clear Delete Queue
1137         // - I should probably put this in a worker thread to avoid calling free() in the scheduler
1138         //   DEFINITELY - free() can deadlock in this case
1139         //   I'll do it when it becomes an issue
1140         while(gDeleteThreads)
1141         {
1142                 thread = gDeleteThreads->Next;
1143                 // Only free if structure is unused
1144                 if( !IS_LOCKED(&gDeleteThreads->IsLocked) )
1145                 {
1146                         // Set to dead
1147                         gDeleteThreads->Status = THREAD_STAT_BURIED;
1148                         // Free name
1149                         if( IsHeap(gDeleteThreads->ThreadName) )
1150                                 free(gDeleteThreads->ThreadName);
1151                         // Remove from global list
1152                         if( gDeleteThreads == gAllThreads )
1153                                 gAllThreads = gDeleteThreads->GlobalNext;
1154                         else
1155                                 gDeleteThreads->GlobalPrev->GlobalNext = gDeleteThreads->GlobalNext;
1156                         free( gDeleteThreads );
1157                 }
1158                 gDeleteThreads = thread;
1159         }
1160
1161         // Make sure the current (well, old) thread is marked as de-scheduled
1162         if(Last)        Last->CurCPU = -1;
1163
1164         // No active threads, just take a nap
1165         if(giNumActiveThreads == 0) {
1166                 SHORTREL( &glThreadListLock );
1167                 #if DEBUG_TRACE_TICKETS
1168                 Log("No active threads");
1169                 #endif
1170                 return NULL;
1171         }
1172
1173         #if SCHEDULER_TYPE != SCHED_RR_PRI
1174         // Special case: 1 thread
1175         if(giNumActiveThreads == 1) {
1176                 if( gActiveThreads->CurCPU == -1 )
1177                         gActiveThreads->CurCPU = CPU;
1178
1179                 SHORTREL( &glThreadListLock );
1180
1181                 if( gActiveThreads->CurCPU == CPU )
1182                         return gActiveThreads;
1183
1184                 return NULL;    // CPU has nothing to do
1185         }
1186         #endif
1187
1188         // Allow the old thread to be scheduled again
1189         if( Last ) {
1190                 if( Last->Status == THREAD_STAT_ACTIVE ) {
1191                         #if SCHEDULER_TYPE == SCHED_LOTTERY
1192                         giFreeTickets += caiTICKET_COUNTS[ Last->Priority ];
1193                         # if DEBUG_TRACE_TICKETS
1194                         LogF("Log: CPU%i released %p (%i %s) into the pool (%i [+%i] tickets in pool)\n",
1195                                 CPU, Last, Last->TID, Last->ThreadName, giFreeTickets,
1196                                 caiTICKET_COUNTS[ Last->Priority ]);
1197                         # endif
1198                         #endif
1199                 }
1200                 #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
1201                 else
1202                         LogF("Log: CPU%i released %p (%i %s)->Status = %i (Released,not in pool)\n",
1203                                 CPU, Last, Last->TID, Last->ThreadName, Last->Status);
1204                 #endif
1205                 Last->CurCPU = -1;
1206         }
1207
1208         // ---
1209         // Lottery Scheduler
1210         // ---
1211         #if SCHEDULER_TYPE == SCHED_LOTTERY
1212         {
1213                  int    ticket, number;
1214                 # if 1
1215                 number = 0;
1216                 for(thread = gActiveThreads; thread; thread = thread->Next) {
1217                         if(thread->CurCPU >= 0) continue;
1218                         if(thread->Status != THREAD_STAT_ACTIVE)
1219                                 Panic("Bookkeeping fail - %p %i(%s) is on the active queue with a status of %i",
1220                                         thread, thread->TID, thread->ThreadName, thread->Status);
1221                         if(thread->Next == thread) {
1222                                 Panic("Bookkeeping fail - %p %i(%s) loops back on itself",
1223                                         thread, thread->TID, thread->ThreadName, thread->Status);
1224                         }
1225                         number += caiTICKET_COUNTS[ thread->Priority ];
1226                 }
1227                 if(number != giFreeTickets) {
1228                         Panic("Bookkeeping fail (giFreeTickets(%i) != number(%i)) - CPU%i",
1229                                 giFreeTickets, number, CPU);
1230                 }
1231                 # endif
1232
1233                 // No free tickets (all tasks delegated to cores)
1234                 if( giFreeTickets == 0 ) {
1235                         SHORTREL(&glThreadListLock);
1236                         return NULL;
1237                 }
1238
1239                 // Get the ticket number
1240                 ticket = number = rand() % giFreeTickets;
1241
1242                 // Find the next thread
1243                 for(thread=gActiveThreads;thread;thread=thread->Next)
1244                 {
1245                         if(thread->CurCPU >= 0) continue;
1246                         if( caiTICKET_COUNTS[ thread->Priority ] > number)      break;
1247                         number -= caiTICKET_COUNTS[ thread->Priority ];
1248                 }
1249
1250                 // If we didn't find a thread, something went wrong
1251                 if(thread == NULL)
1252                 {
1253                         number = 0;
1254                         for(thread=gActiveThreads;thread;thread=thread->Next) {
1255                                 if(thread->CurCPU >= 0) continue;
1256                                 number += caiTICKET_COUNTS[ thread->Priority ];
1257                         }
1258                         Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)",
1259                                 giFreeTickets, number);
1260                 }
1261
1262                 giFreeTickets -= caiTICKET_COUNTS[ thread->Priority ];
1263                 # if DEBUG_TRACE_TICKETS
1264                 LogF("Log: CPU%i allocated %p (%i %s), (%i [-%i] tickets in pool), \n",
1265                         CPU, thread, thread->TID, thread->ThreadName,
1266                         giFreeTickets, caiTICKET_COUNTS[ thread->Priority ]);
1267                 # endif
1268         }
1269
1270         // ---
1271         // Priority based round robin scheduler
1272         // ---
1273         #elif SCHEDULER_TYPE == SCHED_RR_PRI
1274         {
1275                  int    i;
1276                 for( i = 0; i < MIN_PRIORITY + 1; i ++ )
1277                 {
1278                         for(thread = gaActiveThreads[i]; thread; thread = thread->Next)
1279                         {
1280                                 if( thread->CurCPU == -1 )      break;
1281                         }
1282                         // If we fall onto the same queue again, special handling is
1283                         // needed
1284                         if( Last && Last->Status == THREAD_STAT_ACTIVE && i == Last->Priority ) {
1285                                 tThread *savedThread = thread;
1286
1287                                 // Find the next unscheduled thread in the list
1288                                 for( thread = Last->Next; thread; thread = thread->Next )
1289                                 {
1290                                         if( thread->CurCPU == -1 )      break;
1291                                 }
1292                                 // If we don't find anything after, just use the one
1293                                 // found above.
1294                                 if( !thread )   thread = savedThread;
1295                         }
1296                         // Found a thread? Schedule it!
1297                         if( thread )    break;
1298                 }
1299
1300                 // Anything to do?
1301                 if( !thread ) {
1302                         SHORTREL(&glThreadListLock);
1303                         return NULL;
1304                 }
1305                 if( thread->Status != THREAD_STAT_ACTIVE ) {
1306                         LogF("Oops, Thread %i (%s) is not active\n", thread->TID, thread->ThreadName);
1307                 }
1308         }
1309         #elif SCHEDULER_TYPE == SCHED_RR_SIM
1310         {
1311                 // Find the next unscheduled thread in the list
1312                 for( thread = Last->Next; thread; thread = thread->Next )
1313                 {
1314                         if( thread->CurCPU == -1 )      break;
1315                 }
1316                 // If we don't find anything after, search from the beginning
1317                 if( !thread )
1318                 {
1319                         for(thread = gActiveThreads; thread; thread = thread->Next)
1320                         {
1321                                 if( thread->CurCPU == -1 )      break;
1322                         }
1323                 }
1324
1325                 // Anything to do?
1326                 if( !thread ) {
1327                         SHORTREL(&glThreadListLock);
1328                         return NULL;
1329                 }
1330         }
1331         #else
1332         # error "Unimplemented scheduling algorithm"
1333         #endif
1334
1335         // Make the new thread non-schedulable
1336         thread->CurCPU = CPU;
1337         thread->Remaining = thread->Quantum;
1338
1339         SHORTREL( &glThreadListLock );
1340
1341         return thread;
1342 }
1343
1344 // Acquire mutex (see mutex.h for documentation)
1345 int Mutex_Acquire(tMutex *Mutex)
1346 {
1347         tThread *us = Proc_GetCurThread();
1348
1349         // Get protector
1350         SHORTLOCK( &Mutex->Protector );
1351
1352         //Log("Mutex_Acquire: (%p)", Mutex);
1353
1354         // Check if the lock is already held
1355         if( Mutex->Owner ) {
1356                 SHORTLOCK( &glThreadListLock );
1357                 // - Remove from active list
1358                 us = Threads_RemActive();
1359                 us->Next = NULL;
1360                 // - Mark as sleeping
1361                 us->Status = THREAD_STAT_MUTEXSLEEP;
1362                 us->WaitPointer = Mutex;
1363
1364                 // - Add to waiting
1365                 if(Mutex->LastWaiting) {
1366                         Mutex->LastWaiting->Next = us;
1367                         Mutex->LastWaiting = us;
1368                 }
1369                 else {
1370                         Mutex->Waiting = us;
1371                         Mutex->LastWaiting = us;
1372                 }
1373
1374                 #if DEBUG_TRACE_STATE
1375                 Log("%p (%i %s) waiting on mutex %p",
1376                         us, us->TID, us->ThreadName, Mutex);
1377                 #endif
1378
1379                 #if 0
1380                 {
1381                          int    i = 0;
1382                         tThread *t;
1383                         for( t = Mutex->Waiting; t; t = t->Next, i++ )
1384                                 Log("[%i] (tMutex)%p->Waiting[%i] = %p (%i %s)", us->TID, Mutex, i,
1385                                         t, t->TID, t->ThreadName);
1386                 }
1387                 #endif
1388
1389                 SHORTREL( &glThreadListLock );
1390                 SHORTREL( &Mutex->Protector );
1391                 while(us->Status == THREAD_STAT_MUTEXSLEEP)     Threads_Yield();
1392                 // We're only woken when we get the lock
1393                 us->WaitPointer = NULL;
1394         }
1395         // Ooh, let's take it!
1396         else {
1397                 Mutex->Owner = us;
1398                 SHORTREL( &Mutex->Protector );
1399         }
1400
1401         #if 0
1402         extern tMutex   glPhysAlloc;
1403         if( Mutex != &glPhysAlloc )
1404                 LogF("Mutex %p taken by %i %p\n", Mutex, us->TID, __builtin_return_address(0));
1405         #endif
1406
1407         return 0;
1408 }
1409
1410 // Release a mutex
1411 void Mutex_Release(tMutex *Mutex)
1412 {
1413         SHORTLOCK( &Mutex->Protector );
1414         //Log("Mutex_Release: (%p)", Mutex);
1415         if( Mutex->Waiting ) {
1416                 Mutex->Owner = Mutex->Waiting;  // Set owner
1417                 Mutex->Waiting = Mutex->Waiting->Next;  // Next!
1418                 // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
1419                 // 2010-10-02 21:50 - Comemerating the death of the longest single
1420                 //                    blocker in the Acess2 history. REMEMBER TO
1421                 //                    FUCKING MAINTAIN YOUR FUCKING LISTS DIPWIT
1422                 if( Mutex->LastWaiting == Mutex->Owner )
1423                         Mutex->LastWaiting = NULL;
1424
1425                 // Wake new owner
1426                 SHORTLOCK( &glThreadListLock );
1427                 if( Mutex->Owner->Status != THREAD_STAT_ACTIVE )
1428                         Threads_AddActive(Mutex->Owner);
1429                 SHORTREL( &glThreadListLock );
1430         }
1431         else {
1432                 Mutex->Owner = NULL;
1433         }
1434         SHORTREL( &Mutex->Protector );
1435
1436         #if 0
1437         extern tMutex   glPhysAlloc;
1438         if( Mutex != &glPhysAlloc )
1439                 LogF("Mutex %p released by %i %p\n", Mutex, Threads_GetTID(), __builtin_return_address(0));
1440         #endif
1441 }
1442
1443 // Check if a mutex is locked
1444 int Mutex_IsLocked(tMutex *Mutex)
1445 {
1446         return Mutex->Owner != NULL;
1447 }
1448
1449 //
1450 // Initialise a semaphore
1451 //
1452 void Semaphore_Init(tSemaphore *Sem, int Value, int MaxValue, const char *Module, const char *Name)
1453 {
1454         memset(Sem, 0, sizeof(tSemaphore));
1455         Sem->Value = Value;
1456         Sem->ModName = Module;
1457         Sem->Name = Name;
1458         Sem->MaxValue = MaxValue;
1459 }
1460 //
1461 // Wait for items to be avaliable
1462 //
1463 int Semaphore_Wait(tSemaphore *Sem, int MaxToTake)
1464 {
1465         tThread *us;
1466          int    taken;
1467         if( MaxToTake < 0 ) {
1468                 Log_Warning("Threads", "Semaphore_Wait: User bug - MaxToTake(%i) < 0, Sem=%p(%s)",
1469                         MaxToTake, Sem, Sem->Name);
1470         }
1471
1472         SHORTLOCK( &Sem->Protector );
1473
1474         // Check if there's already items avaliable
1475         if( Sem->Value > 0 ) {
1476                 // Take what we need
1477                 if( MaxToTake && Sem->Value > MaxToTake )
1478                         taken = MaxToTake;
1479                 else
1480                         taken = Sem->Value;
1481                 Sem->Value -= taken;
1482         }
1483         else
1484         {
1485                 SHORTLOCK( &glThreadListLock );
1486
1487                 // - Remove from active list
1488                 us = Threads_RemActive();
1489                 us->Next = NULL;
1490                 // - Mark as sleeping
1491                 us->Status = THREAD_STAT_SEMAPHORESLEEP;
1492                 us->WaitPointer = Sem;
1493                 us->RetStatus = MaxToTake;      // Use RetStatus as a temp variable
1494
1495                 // - Add to waiting
1496                 if(Sem->LastWaiting) {
1497                         Sem->LastWaiting->Next = us;
1498                         Sem->LastWaiting = us;
1499                 }
1500                 else {
1501                         Sem->Waiting = us;
1502                         Sem->LastWaiting = us;
1503                 }
1504
1505                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1506                 Log("%p (%i %s) waiting on semaphore %p %s:%s",
1507                         us, us->TID, us->ThreadName,
1508                         Sem, Sem->ModName, Sem->Name);
1509                 #endif
1510
1511                 SHORTREL( &Sem->Protector );    // Release first to make sure it is released
1512                 SHORTREL( &glThreadListLock );
1513                 while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
1514                 // We're only woken when there's something avaliable (or a signal arrives)
1515                 us->WaitPointer = NULL;
1516
1517                 taken = us->RetStatus;
1518
1519                 // Get the lock again
1520                 SHORTLOCK( &Sem->Protector );
1521         }
1522
1523         // While there is space, and there are thread waiting
1524         // wake the first thread and give it what it wants (or what's left)
1525         while( (Sem->MaxValue == 0 || Sem->Value < Sem->MaxValue) && Sem->Signaling )
1526         {
1527                  int    given;
1528                 tThread *toWake = Sem->Signaling;
1529
1530                 Sem->Signaling = Sem->Signaling->Next;
1531                 // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
1532                 if( Sem->Signaling == NULL )
1533                         Sem->LastSignaling = NULL;
1534
1535                 // Figure out how much to give
1536                 if( toWake->RetStatus && Sem->Value + toWake->RetStatus < Sem->MaxValue )
1537                         given = toWake->RetStatus;
1538                 else
1539                         given = Sem->MaxValue - Sem->Value;
1540                 Sem->Value -= given;
1541
1542
1543                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1544                 Log("%p (%i %s) woken by wait on %p %s:%s",
1545                         toWake, toWake->TID, toWake->ThreadName,
1546                         Sem, Sem->ModName, Sem->Name);
1547                 #endif
1548
1549                 // Save the number we gave to the thread's status
1550                 toWake->RetStatus = given;
1551
1552                 // Wake the sleeper
1553                 SHORTLOCK( &glThreadListLock );
1554                 if( toWake->Status != THREAD_STAT_ACTIVE )
1555                         Threads_AddActive(toWake);
1556                 SHORTREL( &glThreadListLock );
1557         }
1558         SHORTREL( &Sem->Protector );
1559
1560         return taken;
1561 }
1562
1563 //
1564 // Add items to a semaphore
1565 //
1566 int Semaphore_Signal(tSemaphore *Sem, int AmmountToAdd)
1567 {
1568          int    given;
1569          int    added;
1570
1571         if( AmmountToAdd < 0 ) {
1572                 Log_Warning("Threads", "Semaphore_Signal: User bug - AmmountToAdd(%i) < 0, Sem=%p(%s)",
1573                         AmmountToAdd, Sem, Sem->Name);
1574         }
1575         SHORTLOCK( &Sem->Protector );
1576
1577         // Check if we have to block
1578         if( Sem->MaxValue && Sem->Value == Sem->MaxValue )
1579         {
1580                 tThread *us;
1581                 #if 0
1582                 Log_Debug("Threads", "Semaphore_Signal: IDLE Sem = %s:%s", Sem->ModName, Sem->Name);
1583                 Log_Debug("Threads", "Semaphore_Signal: Sem->Value(%i) == Sem->MaxValue(%i)", Sem->Value, Sem->MaxValue);
1584                 #endif
1585
1586                 SHORTLOCK( &glThreadListLock );
1587                 // - Remove from active list
1588                 us = Threads_RemActive();
1589                 us->Next = NULL;
1590                 // - Mark as sleeping
1591                 us->Status = THREAD_STAT_SEMAPHORESLEEP;
1592                 us->WaitPointer = Sem;
1593                 us->RetStatus = AmmountToAdd;   // Use RetStatus as a temp variable
1594
1595                 // - Add to waiting
1596                 if(Sem->LastSignaling) {
1597                         Sem->LastSignaling->Next = us;
1598                         Sem->LastSignaling = us;
1599                 }
1600                 else {
1601                         Sem->Signaling = us;
1602                         Sem->LastSignaling = us;
1603                 }
1604
1605                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1606                 Log("%p (%i %s) signaling semaphore %p %s:%s",
1607                         us, us->TID, us->ThreadName,
1608                         Sem, Sem->ModName, Sem->Name);
1609                 #endif
1610
1611                 SHORTREL( &glThreadListLock );
1612                 SHORTREL( &Sem->Protector );
1613                 while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
1614                 // We're only woken when there's something avaliable
1615                 us->WaitPointer = NULL;
1616
1617                 added = us->RetStatus;
1618
1619                 // Get the lock again
1620                 SHORTLOCK( &Sem->Protector );
1621         }
1622         // Non blocking
1623         else
1624         {
1625                 // Figure out how much we need to take off
1626                 if( Sem->MaxValue && Sem->Value + AmmountToAdd > Sem->MaxValue)
1627                         added = Sem->MaxValue - Sem->Value;
1628                 else
1629                         added = AmmountToAdd;
1630                 Sem->Value += added;
1631         }
1632
1633         // While there are items avaliable, and there are thread waiting
1634         // wake the first thread and give it what it wants (or what's left)
1635         while( Sem->Value && Sem->Waiting )
1636         {
1637                 tThread *toWake = Sem->Waiting;
1638
1639                 // Remove thread from list (double ended, so clear LastWaiting if needed)
1640                 Sem->Waiting = Sem->Waiting->Next;
1641                 if( Sem->Waiting == NULL )
1642                         Sem->LastWaiting = NULL;
1643
1644                 // Figure out how much to give to woken thread
1645                 // - Requested count is stored in ->RetStatus
1646                 if( toWake->RetStatus && Sem->Value > toWake->RetStatus )
1647                         given = toWake->RetStatus;
1648                 else
1649                         given = Sem->Value;
1650                 Sem->Value -= given;
1651
1652                 // Save the number we gave to the thread's status
1653                 toWake->RetStatus = given;
1654
1655                 if(toWake->bInstrTrace)
1656                         Log("%s(%i) given %i from %p", toWake->ThreadName, toWake->TID, given, Sem);
1657                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1658                 Log("%p (%i %s) woken by signal on %p %s:%s",
1659                         toWake, toWake->TID, toWake->ThreadName,
1660                         Sem, Sem->ModName, Sem->Name);
1661                 #endif
1662
1663                 // Wake the sleeper
1664 //              SHORTLOCK( &glThreadListLock );
1665                 if( toWake->Status != THREAD_STAT_ACTIVE )
1666                         Threads_AddActive(toWake);
1667                 else
1668                         Warning("Thread %p (%i %s) is already awake", toWake, toWake->TID, toWake->ThreadName);
1669 //              SHORTREL( &glThreadListLock );
1670         }
1671         SHORTREL( &Sem->Protector );
1672
1673         return added;
1674 }
1675
1676 //
1677 // Get the current value of a semaphore
1678 //
1679 int Semaphore_GetValue(tSemaphore *Sem)
1680 {
1681         return Sem->Value;
1682 }
1683
1684 // === EXPORTS ===
1685 EXPORT(Threads_GetUID);
1686 EXPORT(Threads_GetGID);
1687 EXPORT(Mutex_Acquire);
1688 EXPORT(Mutex_Release);
1689 EXPORT(Mutex_IsLocked);
1690 EXPORT(Semaphore_Init);
1691 EXPORT(Semaphore_Wait);
1692 EXPORT(Semaphore_Signal);