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  * \fn tThread *Threads_CloneTCB(Uint *Err, Uint Flags)
 237  * \brief Clone the TCB of the current thread
 238  * \param Err   Error pointer
 239  * \param Flags Flags for something... (What is this for?)
 240  */
 241 tThread *Threads_CloneTCB(Uint *Err, Uint Flags)
 242 {
 243         tThread *cur, *new;
 244          int    i;
 245         cur = Proc_GetCurThread();
 246
 247         // Allocate and duplicate
 248         new = malloc(sizeof(tThread));
 249         if(new == NULL) { *Err = -ENOMEM; return NULL; }
 250         memcpy(new, cur, sizeof(tThread));
 251
 252         new->CurCPU = -1;
 253         new->Next = NULL;
 254         memset( &new->IsLocked, 0, sizeof(new->IsLocked));
 255         new->Status = THREAD_STAT_PREINIT;
 256         new->RetStatus = 0;
 257
 258         // Get Thread ID
 259         new->TID = giNextTID++;
 260         new->Parent = cur;
 261         new->bInstrTrace = 0;
 262
 263         // Clone Name
 264         new->ThreadName = strdup(cur->ThreadName);
 265
 266         // Set Thread Group ID (PID)
 267         if(Flags & CLONE_VM)
 268                 new->TGID = new->TID;
 269         else
 270                 new->TGID = cur->TGID;
 271
 272         // Messages are not inherited
 273         new->Messages = NULL;
 274         new->LastMessage = NULL;
 275
 276         // Set State
 277         new->Remaining = new->Quantum = cur->Quantum;
 278         new->Priority = cur->Priority;
 279
 280         // Set Signal Handlers
 281         new->CurFaultNum = 0;
 282         new->FaultHandler = cur->FaultHandler;
 283
 284         for( i = 0; i < NUM_CFG_ENTRIES; i ++ )
 285         {
 286                 switch(cCONFIG_TYPES[i])
 287                 {
 288                 default:
 289                         new->Config[i] = cur->Config[i];
 290                         break;
 291                 case CFGT_HEAPSTR:
 292                         if(cur->Config[i])
 293                                 new->Config[i] = (Uint) strdup( (void*)cur->Config[i] );
 294                         else
 295                                 new->Config[i] = 0;
 296                         break;
 297                 }
 298         }
 299
 300         // Maintain a global list of threads
 301         SHORTLOCK( &glThreadListLock );
 302         new->GlobalPrev = NULL; // Protect against bugs
 303         new->GlobalNext = gAllThreads;
 304         gAllThreads->GlobalPrev = new;
 305         gAllThreads = new;
 306         SHORTREL( &glThreadListLock );
 307
 308         return new;
 309 }
 310
 311 /**
 312  * \fn tThread *Threads_CloneTCB(Uint *Err, Uint Flags)
 313  * \brief Clone the TCB of the current thread
 314  */
 315 tThread *Threads_CloneThreadZero(void)
 316 {
 317         tThread *cur, *new;
 318          int    i;
 319         cur = Proc_GetCurThread();
 320
 321         // Allocate and duplicate
 322         new = malloc(sizeof(tThread));
 323         if(new == NULL) {
 324                 return NULL;
 325         }
 326         memcpy(new, &gThreadZero, sizeof(tThread));
 327
 328         new->CurCPU = -1;
 329         new->Next = NULL;
 330         memset( &new->IsLocked, 0, sizeof(new->IsLocked));
 331         new->Status = THREAD_STAT_PREINIT;
 332         new->RetStatus = 0;
 333
 334         // Get Thread ID
 335         new->TID = giNextTID++;
 336         new->Parent = 0;
 337
 338         // Clone Name
 339         new->ThreadName = NULL;
 340
 341         // Messages are not inherited
 342         new->Messages = NULL;
 343         new->LastMessage = NULL;
 344
 345         // Set State
 346         new->Remaining = new->Quantum = cur->Quantum;
 347         new->Priority = cur->Priority;
 348         new->bInstrTrace = 0;
 349
 350         // Set Signal Handlers
 351         new->CurFaultNum = 0;
 352         new->FaultHandler = cur->FaultHandler;
 353
 354         for( i = 0; i < NUM_CFG_ENTRIES; i ++ )
 355         {
 356                 switch(cCONFIG_TYPES[i])
 357                 {
 358                 default:
 359                         new->Config[i] = cur->Config[i];
 360                         break;
 361                 case CFGT_HEAPSTR:
 362                         if(cur->Config[i])
 363                                 new->Config[i] = (Uint) strdup( (void*)cur->Config[i] );
 364                         else
 365                                 new->Config[i] = 0;
 366                         break;
 367                 }
 368         }
 369
 370         // Maintain a global list of threads
 371         SHORTLOCK( &glThreadListLock );
 372         new->GlobalPrev = NULL; // Protect against bugs
 373         new->GlobalNext = gAllThreads;
 374         gAllThreads->GlobalPrev = new;
 375         gAllThreads = new;
 376         SHORTREL( &glThreadListLock );
 377
 378         return new;
 379 }
 380
 381 /**
 382  * \brief Get a configuration pointer from the Per-Thread data area
 383  * \param ID    Config slot ID
 384  * \return Pointer at ID
 385  */
 386 Uint *Threads_GetCfgPtr(int ID)
 387 {
 388         if(ID < 0 || ID >= NUM_CFG_ENTRIES) {
 389                 Warning("Threads_GetCfgPtr: Index %i is out of bounds", ID);
 390                 return NULL;
 391         }
 392
 393         return &Proc_GetCurThread()->Config[ID];
 394 }
 395
 396 /**
 397  * \brief Wait for a task to change state
 398  * \param TID   Thread ID to wait on (-1: Any child thread, 0: Any Child/Sibling, <-1: -PID)
 399  * \param Status        Thread return status
 400  * \return TID of child that changed state
 401  */
 402 tTID Threads_WaitTID(int TID, int *Status)
 403 {
 404         // Any Child
 405         if(TID == -1) {
 406                 Log_Error("Threads", "TODO: Threads_WaitTID(TID=-1) - Any Child");
 407                 return -1;
 408         }
 409
 410         // Any peer/child thread
 411         if(TID == 0) {
 412                 Log_Error("Threads", "TODO: Threads_WaitTID(TID=0) - Any Child/Sibling");
 413                 return -1;
 414         }
 415
 416         // TGID = abs(TID)
 417         if(TID < -1) {
 418                 Log_Error("Threads", "TODO: Threads_WaitTID(TID<0) - TGID");
 419                 return -1;
 420         }
 421
 422         // Specific Thread
 423         if(TID > 0) {
 424                 tThread *t = Threads_GetThread(TID);
 425                  int    initStatus = t->Status;
 426                 tTID    ret;
 427
 428                 // Wait for the thread to die!
 429                 if(initStatus != THREAD_STAT_ZOMBIE) {
 430                         // TODO: Handle child also being suspended if wanted
 431                         while(t->Status != THREAD_STAT_ZOMBIE) {
 432                                 Threads_Sleep();
 433                                 Log_Debug("Threads", "%i waiting for %i, t->Status = %i",
 434                                         Threads_GetTID(), t->TID, t->Status);
 435                         }
 436                 }
 437
 438                 // Set return status
 439                 Log_Debug("Threads", "%i waiting for %i, t->Status = %i",
 440                         Threads_GetTID(), t->TID, t->Status);
 441                 ret = t->TID;
 442                 switch(t->Status)
 443                 {
 444                 case THREAD_STAT_ZOMBIE:
 445                         // Kill the thread
 446                         t->Status = THREAD_STAT_DEAD;
 447                         // TODO: Child return value?
 448                         if(Status)      *Status = t->RetStatus;
 449                         // add to delete queue
 450                         Threads_AddToDelete( t );
 451                         break;
 452                 default:
 453                         if(Status)      *Status = -1;
 454                         break;
 455                 }
 456                 return ret;
 457         }
 458
 459         return -1;
 460 }
 461
 462 /**
 463  * \brief Gets a thread given its TID
 464  * \param TID   Thread ID
 465  * \return Thread pointer
 466  */
 467 tThread *Threads_GetThread(Uint TID)
 468 {
 469         tThread *thread;
 470
 471         // Search global list
 472         for(thread = gAllThreads;
 473                 thread;
 474                 thread = thread->GlobalNext)
 475         {
 476                 if(thread->TID == TID)
 477                         return thread;
 478         }
 479
 480         Log("Unable to find TID %i on main list\n", TID);
 481
 482         return NULL;
 483 }
 484
 485 /**
 486  * \brief Adds a thread to the delete queue
 487  * \param Thread        Thread to delete
 488  */
 489 void Threads_AddToDelete(tThread *Thread)
 490 {
 491         // Add to delete queue
 492         // TODO: Is locking needed?
 493         if(gDeleteThreads) {
 494                 Thread->Next = gDeleteThreads;
 495                 gDeleteThreads = Thread;
 496         } else {
 497                 Thread->Next = NULL;
 498                 gDeleteThreads = Thread;
 499         }
 500 }
 501
 502 /**
 503  * \brief Deletes an entry from a list
 504  * \param List  Pointer to the list head
 505  * \param Thread        Thread to find
 506  * \return \a Thread
 507  */
 508 tThread *Threads_int_DelFromQueue(tThread **List, tThread *Thread)
 509 {
 510         tThread *ret, *prev = NULL;
 511
 512         for(ret = *List;
 513                 ret && ret != Thread;
 514                 prev = ret, ret = ret->Next
 515                 );
 516
 517         // Is the thread on the list
 518         if(!ret) {
 519                 //LogF("%p(%s) is not on list %p\n", Thread, Thread->ThreadName, List);
 520                 return NULL;
 521         }
 522
 523         if( !prev ) {
 524                 *List = Thread->Next;
 525                 //LogF("%p(%s) removed from head of %p\n", Thread, Thread->ThreadName, List);
 526         }
 527         else {
 528                 prev->Next = Thread->Next;
 529                 //LogF("%p(%s) removed from %p (prev=%p)\n", Thread, Thread->ThreadName, List, prev);
 530         }
 531
 532         return Thread;
 533 }
 534
 535 /**
 536  * \brief Exit the current process (or another?)
 537  * \param TID   Thread ID to kill
 538  * \param Status        Exit status
 539  */
 540 void Threads_Exit(int TID, int Status)
 541 {
 542         if( TID == 0 )
 543                 Threads_Kill( Proc_GetCurThread(), (Uint)Status & 0xFF );
 544         else
 545                 Threads_Kill( Threads_GetThread(TID), (Uint)Status & 0xFF );
 546
 547         // Halt forever, just in case
 548         for(;;) HALT();
 549 }
 550
 551 /**
 552  * \fn void Threads_Kill(tThread *Thread, int Status)
 553  * \brief Kill a thread
 554  * \param Thread        Thread to kill
 555  * \param Status        Status code to return to the parent
 556  */
 557 void Threads_Kill(tThread *Thread, int Status)
 558 {
 559         tMsg    *msg;
 560          int    isCurThread = Thread == Proc_GetCurThread();
 561
 562         // TODO: Kill all children
 563         #if 1
 564         {
 565                 tThread *child;
 566                 // TODO: I should keep a .Parent pointer, and a .Children list
 567                 for(child = gAllThreads;
 568                         child;
 569                         child = child->GlobalNext)
 570                 {
 571                         if(child->Parent == Thread)
 572                                 Threads_Kill(child, -1);
 573                 }
 574         }
 575         #endif
 576
 577         ///\note Double lock is needed due to overlap of lock areas
 578
 579         // Lock thread (stop us recieving messages)
 580         SHORTLOCK( &Thread->IsLocked );
 581
 582         // Clear Message Queue
 583         while( Thread->Messages )
 584         {
 585                 msg = Thread->Messages->Next;
 586                 free( Thread->Messages );
 587                 Thread->Messages = msg;
 588         }
 589
 590         // Lock thread list
 591         SHORTLOCK( &glThreadListLock );
 592
 593         switch(Thread->Status)
 594         {
 595         case THREAD_STAT_PREINIT:       // Only on main list
 596                 break;
 597
 598         // Currently active thread
 599         case THREAD_STAT_ACTIVE:
 600                 #if SCHEDULER_TYPE == SCHED_RR_PRI
 601                 if( Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread ) )
 602                 #else
 603                 if( Threads_int_DelFromQueue( &gActiveThreads, Thread ) )
 604                 #endif
 605                 {
 606                         // Ensure that we are not rescheduled
 607                         Thread->Remaining = 0;  // Clear Remaining Quantum
 608                         Thread->Quantum = 0;    // Clear Quantum to indicate dead thread
 609
 610                         // Update bookkeeping
 611                         giNumActiveThreads --;
 612                         #if SCHEDULER_TYPE == SCHED_LOTTERY
 613                         if( Thread != Proc_GetCurThread() )
 614                                 giFreeTickets -= caiTICKET_COUNTS[ Thread->Priority ];
 615                         #endif
 616                 }
 617                 else
 618                 {
 619                         Log_Warning("Threads",
 620                                 "Threads_Kill - Thread %p(%i,%s) marked as active, but not on list",
 621                                 Thread, Thread->TID, Thread->ThreadName
 622                                 );
 623                 }
 624                 break;
 625         // Kill it while it sleeps!
 626         case THREAD_STAT_SLEEPING:
 627                 if( !Threads_int_DelFromQueue( &gSleepingThreads, Thread ) )
 628                 {
 629                         Log_Warning("Threads",
 630                                 "Threads_Kill - Thread %p(%i,%s) marked as sleeping, but not on list",
 631                                 Thread, Thread->TID, Thread->ThreadName
 632                                 );
 633                 }
 634                 break;
 635
 636         // Brains!... You cannot kill
 637         case THREAD_STAT_ZOMBIE:
 638                 Log_Warning("Threads", "Threads_Kill - Thread %p(%i,%s) is undead, you cannot kill it",
 639                         Thread, Thread->TID, Thread->ThreadName);
 640                 SHORTREL( &glThreadListLock );
 641                 SHORTREL( &Thread->IsLocked );
 642                 return ;
 643
 644         default:
 645                 Log_Warning("Threads", "Threads_Kill - BUG Un-checked status (%i)",
 646                         Thread->Status);
 647                 break;
 648         }
 649
 650         // Save exit status
 651         Thread->RetStatus = Status;
 652
 653         // Don't Zombie if we are being killed because our parent is
 654         if(Status == -1)
 655         {
 656                 Thread->Status = THREAD_STAT_DEAD;
 657                 Threads_AddToDelete( Thread );
 658         } else {
 659                 Thread->Status = THREAD_STAT_ZOMBIE;
 660                 // Wake parent
 661                 Threads_Wake( Thread->Parent );
 662         }
 663
 664         Log("Thread %i went *hurk* (%i)", Thread->TID, Status);
 665
 666         // Release spinlocks
 667         SHORTREL( &glThreadListLock );
 668         SHORTREL( &Thread->IsLocked );  // TODO: We may not actually be released...
 669
 670         // And, reschedule
 671         if(isCurThread)
 672         {
 673                 for( ;; )
 674                         Proc_Reschedule();
 675         }
 676 }
 677
 678 /**
 679  * \brief Yield remainder of the current thread's timeslice
 680  */
 681 void Threads_Yield(void)
 682 {
 683         Proc_Reschedule();
 684 }
 685
 686 /**
 687  * \fn void Threads_Sleep(void)
 688  * \brief Take the current process off the run queue
 689  */
 690 void Threads_Sleep(void)
 691 {
 692         tThread *cur = Proc_GetCurThread();
 693
 694         // Acquire Spinlock
 695         SHORTLOCK( &glThreadListLock );
 696
 697         // Don't sleep if there is a message waiting
 698         if( cur->Messages ) {
 699                 SHORTREL( &glThreadListLock );
 700                 return;
 701         }
 702
 703         // Remove us from running queue
 704         Threads_RemActive();
 705         // Mark thread as sleeping
 706         cur->Status = THREAD_STAT_SLEEPING;
 707
 708         // Add to Sleeping List (at the top)
 709         cur->Next = gSleepingThreads;
 710         gSleepingThreads = cur;
 711
 712
 713         #if DEBUG_TRACE_STATE
 714         Log("Threads_Sleep: %p (%i %s) sleeping", cur, cur->TID, cur->ThreadName);
 715         #endif
 716
 717         // Release Spinlock
 718         SHORTREL( &glThreadListLock );
 719
 720         while(cur->Status != THREAD_STAT_ACTIVE)
 721                 Proc_Reschedule();
 722 }
 723
 724
 725 /**
 726  * \fn int Threads_Wake( tThread *Thread )
 727  * \brief Wakes a sleeping/waiting thread up
 728  * \param Thread        Thread to wake
 729  * \return Boolean Failure (Returns ERRNO)
 730  * \warning This should ONLY be called with task switches disabled
 731  */
 732 int Threads_Wake(tThread *Thread)
 733 {
 734         if(!Thread)
 735                 return -EINVAL;
 736
 737         switch(Thread->Status)
 738         {
 739         case THREAD_STAT_ACTIVE:
 740                 Log("Threads_Wake - Waking awake thread (%i)", Thread->TID);
 741                 return -EALREADY;
 742
 743         case THREAD_STAT_SLEEPING:
 744                 SHORTLOCK( &glThreadListLock );
 745                 // Remove from sleeping queue
 746                 Threads_int_DelFromQueue(&gSleepingThreads, Thread);
 747
 748                 Threads_AddActive( Thread );
 749
 750                 #if DEBUG_TRACE_STATE
 751                 Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName);
 752                 #endif
 753                 SHORTREL( &glThreadListLock );
 754                 return -EOK;
 755
 756         case THREAD_STAT_SEMAPHORESLEEP: {
 757                 tSemaphore      *sem;
 758                 tThread *th, *prev=NULL;
 759
 760                 sem = Thread->WaitPointer;
 761
 762                 SHORTLOCK( &sem->Protector );
 763
 764                 // Remove from sleeping queue
 765                 for( th = sem->Waiting; th; prev = th, th = th->Next )
 766                         if( th == Thread )      break;
 767                 if( th )
 768                 {
 769                         if(prev)
 770                                 prev->Next = Thread->Next;
 771                         else
 772                                 sem->Waiting = Thread->Next;
 773                         if(sem->LastWaiting == Thread)
 774                                 sem->LastWaiting = prev;
 775                 }
 776                 else
 777                 {
 778                         prev = NULL;
 779                         for( th = sem->Signaling; th; prev = th, th = th->Next )
 780                                 if( th == Thread )      break;
 781                         if( !th ) {
 782                                 Log_Warning("Threads", "Thread %p(%i %s) is not on semaphore %p(%s:%s)",
 783                                         Thread, Thread->TID, Thread->ThreadName,
 784                                         sem, sem->ModName, sem->Name);
 785                                 return -EINTERNAL;
 786                         }
 787
 788                         if(prev)
 789                                 prev->Next = Thread->Next;
 790                         else
 791                                 sem->Signaling = Thread->Next;
 792                         if(sem->LastSignaling == Thread)
 793                                 sem->LastSignaling = prev;
 794                 }
 795
 796                 SHORTLOCK( &glThreadListLock );
 797                 Threads_AddActive( Thread );
 798                 SHORTREL( &glThreadListLock );
 799
 800                 #if DEBUG_TRACE_STATE
 801                 Log("Threads_Sleep: %p(%i %s) woken from semaphore", Thread, Thread->TID, Thread->ThreadName);
 802                 #endif
 803                 SHORTREL( &sem->Protector );
 804                 } return -EOK;
 805
 806         case THREAD_STAT_WAITING:
 807                 Warning("Threads_Wake - Waiting threads are not currently supported");
 808                 return -ENOTIMPL;
 809
 810         case THREAD_STAT_DEAD:
 811                 Warning("Threads_Wake - Attempt to wake dead thread (%i)", Thread->TID);
 812                 return -ENOTIMPL;
 813
 814         default:
 815                 Warning("Threads_Wake - Unknown process status (%i)\n", Thread->Status);
 816                 return -EINTERNAL;
 817         }
 818 }
 819
 820 /**
 821  * \brief Wake a thread given the TID
 822  * \param TID   Thread ID to wake
 823  * \return Boolean Faulure (errno)
 824  */
 825 int Threads_WakeTID(tTID TID)
 826 {
 827         tThread *thread = Threads_GetThread(TID);
 828          int    ret;
 829         if(!thread)
 830                 return -ENOENT;
 831         ret = Threads_Wake( thread );
 832         //Log_Debug("Threads", "TID %i woke %i (%p)", Threads_GetTID(), TID, thread);
 833         return ret;
 834 }
 835
 836 void Threads_ToggleTrace(int TID)
 837 {
 838         tThread *thread = Threads_GetThread(TID);
 839         if(!thread)     return ;
 840         thread->bInstrTrace = !thread->bInstrTrace;
 841 }
 842
 843 /**
 844  * \brief Adds a thread to the active queue
 845  */
 846 void Threads_AddActive(tThread *Thread)
 847 {
 848         SHORTLOCK( &glThreadListLock );
 849
 850         if( Thread->Status == THREAD_STAT_ACTIVE ) {
 851                 tThread *cur = Proc_GetCurThread();
 852                 Log_Warning("Threads", "WTF, %p CPU%i %p (%i %s) is adding %p (%i %s) when it is active",
 853                         __builtin_return_address(0),
 854                         GetCPUNum(), cur, cur->TID, cur->ThreadName, Thread, Thread->TID, Thread->ThreadName);
 855                 SHORTREL( &glThreadListLock );
 856                 return ;
 857         }
 858
 859         // Set state
 860         Thread->Status = THREAD_STAT_ACTIVE;
 861 //      Thread->CurCPU = -1;
 862         // Add to active list
 863         {
 864                 tThread *tmp, *prev = NULL;
 865                 #if SCHEDULER_TYPE == SCHED_RR_PRI
 866                 for( tmp = gaActiveThreads[Thread->Priority]; tmp; prev = tmp, tmp = tmp->Next );
 867                 if(prev)
 868                         prev->Next = Thread;
 869                 else
 870                         gaActiveThreads[Thread->Priority] = Thread;
 871                 #else
 872                 for( tmp = gActiveThreads; tmp; prev = tmp, tmp = tmp->Next );
 873                 if(prev)
 874                         prev->Next = Thread;
 875                 else
 876                         gActiveThreads = Thread;
 877                 #endif
 878                 Thread->Next = NULL;
 879         }
 880
 881         // Update bookkeeping
 882         giNumActiveThreads ++;
 883
 884         #if SCHEDULER_TYPE == SCHED_LOTTERY
 885         {
 886                  int    delta;
 887                 // Only change the ticket count if the thread is un-scheduled
 888                 if(Thread->CurCPU != -1)
 889                         delta = 0;
 890                 else
 891                         delta = caiTICKET_COUNTS[ Thread->Priority ];
 892
 893                 giFreeTickets += delta;
 894                 # if DEBUG_TRACE_TICKETS
 895                 Log("CPU%i %p (%i %s) added, new giFreeTickets = %i [+%i]",
 896                         GetCPUNum(), Thread, Thread->TID, Thread->ThreadName,
 897                         giFreeTickets, delta
 898                         );
 899                 # endif
 900         }
 901         #endif
 902
 903         SHORTREL( &glThreadListLock );
 904 }
 905
 906 /**
 907  * \brief Removes the current thread from the active queue
 908  * \warning This should ONLY be called with the lock held
 909  * \return Current thread pointer
 910  */
 911 tThread *Threads_RemActive(void)
 912 {
 913         tThread *ret = Proc_GetCurThread();
 914
 915         if( !IS_LOCKED(&glThreadListLock) ) {
 916                 Log_KernelPanic("Threads", "Threads_RemActive called without lock held");
 917                 return NULL;
 918         }
 919
 920         // Delete from active queue
 921         #if SCHEDULER_TYPE == SCHED_RR_PRI
 922         if( !Threads_int_DelFromQueue(&gaActiveThreads[ret->Priority], ret) )
 923         #else
 924         if( !Threads_int_DelFromQueue(&gActiveThreads, ret) )
 925         #endif
 926         {
 927                 SHORTREL( &glThreadListLock );
 928                 Log_Warning("Threads", "Current thread %p(%i %s) is not on active queue",
 929                         ret, ret->TID, ret->ThreadName
 930                         );
 931                 return NULL;
 932         }
 933
 934         ret->Next = NULL;
 935         ret->Remaining = 0;
 936
 937         giNumActiveThreads --;
 938         // no need to decrement tickets, scheduler did it for us
 939
 940         #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
 941         Log("CPU%i %p (%i %s) removed, giFreeTickets = %i [nc]",
 942                 GetCPUNum(), ret, ret->TID, ret->ThreadName, giFreeTickets);
 943         #endif
 944
 945         return ret;
 946 }
 947
 948 /**
 949  * \fn void Threads_SetFaultHandler(Uint Handler)
 950  * \brief Sets the signal handler for a signal
 951  */
 952 void Threads_SetFaultHandler(Uint Handler)
 953 {
 954         //Log_Debug("Threads", "Threads_SetFaultHandler: Handler = %p", Handler);
 955         Proc_GetCurThread()->FaultHandler = Handler;
 956 }
 957
 958 /**
 959  * \fn void Threads_Fault(int Num)
 960  * \brief Calls a fault handler
 961  */
 962 void Threads_Fault(int Num)
 963 {
 964         tThread *thread = Proc_GetCurThread();
 965
 966         if(!thread)     return ;
 967
 968         Log_Log("Threads", "Threads_Fault: thread->FaultHandler = %p", thread->FaultHandler);
 969
 970         switch(thread->FaultHandler)
 971         {
 972         case 0: // Panic?
 973                 Threads_Kill(thread, -1);
 974                 HALT();
 975                 return ;
 976         case 1: // Dump Core?
 977                 Threads_Kill(thread, -1);
 978                 HALT();
 979                 return ;
 980         }
 981
 982         // Double Fault? Oh, F**k
 983         if(thread->CurFaultNum != 0) {
 984                 Log_Warning("Threads", "Threads_Fault: Double fault on %i", thread->TID);
 985                 Threads_Kill(thread, -1);       // For now, just kill
 986                 HALT();
 987         }
 988
 989         thread->CurFaultNum = Num;
 990
 991         Proc_CallFaultHandler(thread);
 992 }
 993
 994 /**
 995  * \fn void Threads_SegFault(tVAddr Addr)
 996  * \brief Called when a Segment Fault occurs
 997  */
 998 void Threads_SegFault(tVAddr Addr)
 999 {
1000         tThread *cur = Proc_GetCurThread();
1001         cur->bInstrTrace = 0;
1002         Log_Warning("Threads", "Thread #%i committed a segfault at address %p", cur->TID, Addr);
1003         MM_DumpTables(0, USER_MAX);
1004         Threads_Fault( 1 );
1005         //Threads_Exit( 0, -1 );
1006 }
1007
1008 // --- Process Structure Access Functions ---
1009 tPID Threads_GetPID(void)
1010 {
1011         return Proc_GetCurThread()->TGID;
1012 }
1013 tTID Threads_GetTID(void)
1014 {
1015         return Proc_GetCurThread()->TID;
1016 }
1017 tUID Threads_GetUID(void)
1018 {
1019         return Proc_GetCurThread()->UID;
1020 }
1021 tGID Threads_GetGID(void)
1022 {
1023         return Proc_GetCurThread()->GID;
1024 }
1025
1026 int Threads_SetUID(Uint *Errno, tUID 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 UID set to %i", t->TID, ID);
1034         t->UID = ID;
1035         return 0;
1036 }
1037
1038 int Threads_SetGID(Uint *Errno, tGID ID)
1039 {
1040         tThread *t = Proc_GetCurThread();
1041         if( t->UID != 0 ) {
1042                 *Errno = -EACCES;
1043                 return -1;
1044         }
1045         Log_Debug("Threads", "TID %i's GID set to %i", t->TID, ID);
1046         t->GID = ID;
1047         return 0;
1048 }
1049
1050 /**
1051  * \fn void Threads_Dump(void)
1052  */
1053 void Threads_DumpActive(void)
1054 {
1055         tThread *thread;
1056         #if SCHEDULER_TYPE == SCHED_RR_PRI
1057          int    i;
1058         #endif
1059
1060         Log("Active Threads: (%i reported)", giNumActiveThreads);
1061
1062         #if SCHEDULER_TYPE == SCHED_RR_PRI
1063         for( i = 0; i < MIN_PRIORITY+1; i++ )
1064         {
1065                 for(thread=gaActiveThreads[i];thread;thread=thread->Next)
1066         #else
1067                 for(thread=gActiveThreads;thread;thread=thread->Next)
1068         #endif
1069                 {
1070                         Log(" %p %i (%i) - %s (CPU %i)",
1071                                 thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
1072                         if(thread->Status != THREAD_STAT_ACTIVE)
1073                                 Log("  ERROR State (%i) != THREAD_STAT_ACTIVE (%i)", thread->Status, THREAD_STAT_ACTIVE);
1074                         Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
1075                         Log("  KStack 0x%x", thread->KernelStack);
1076                         if( thread->bInstrTrace )
1077                                 Log("  Tracing Enabled");
1078                         Proc_DumpThreadCPUState(thread);
1079                 }
1080
1081         #if SCHEDULER_TYPE == SCHED_RR_PRI
1082         }
1083         #endif
1084 }
1085
1086 /**
1087  * \fn void Threads_Dump(void)
1088  * \brief Dumps a list of currently running threads
1089  */
1090 void Threads_Dump(void)
1091 {
1092         tThread *thread;
1093
1094         Log("--- Thread Dump ---");
1095         Threads_DumpActive();
1096
1097         Log("All Threads:");
1098         for(thread=gAllThreads;thread;thread=thread->GlobalNext)
1099         {
1100                 Log(" %p %i (%i) - %s (CPU %i)",
1101                         thread, thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
1102                 Log("  State %i (%s)", thread->Status, casTHREAD_STAT[thread->Status]);
1103                 switch(thread->Status)
1104                 {
1105                 case THREAD_STAT_MUTEXSLEEP:
1106                         Log("  Mutex Pointer: %p", thread->WaitPointer);
1107                         break;
1108                 case THREAD_STAT_SEMAPHORESLEEP:
1109                         Log("  Semaphore Pointer: %p", thread->WaitPointer);
1110                         Log("  Semaphore Name: %s:%s",
1111                                 ((tSemaphore*)thread->WaitPointer)->ModName,
1112                                 ((tSemaphore*)thread->WaitPointer)->Name
1113                                 );
1114                         break;
1115                 case THREAD_STAT_ZOMBIE:
1116                         Log("  Return Status: %i", thread->RetStatus);
1117                         break;
1118                 default:        break;
1119                 }
1120                 Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
1121                 Log("  KStack 0x%x", thread->KernelStack);
1122                 if( thread->bInstrTrace )
1123                         Log("  Tracing Enabled");
1124                 Proc_DumpThreadCPUState(thread);
1125         }
1126 }
1127
1128 /**
1129  * \brief Gets the next thread to run
1130  * \param CPU   Current CPU
1131  * \param Last  The thread the CPU was running
1132  */
1133 tThread *Threads_GetNextToRun(int CPU, tThread *Last)
1134 {
1135         tThread *thread;
1136
1137         // If this CPU has the lock, we must let it complete
1138         if( CPU_HAS_LOCK( &glThreadListLock ) )
1139                 return Last;
1140
1141         // Don't change threads if the current CPU has switches disabled
1142         if( gaThreads_NoTaskSwitch[CPU] )
1143                 return Last;
1144
1145         // Lock thread list
1146         SHORTLOCK( &glThreadListLock );
1147
1148         // Clear Delete Queue
1149         // - I should probably put this in a worker thread to avoid calling free() in the scheduler
1150         //   DEFINITELY - free() can deadlock in this case
1151         //   I'll do it when it becomes an issue
1152         while(gDeleteThreads)
1153         {
1154                 thread = gDeleteThreads->Next;
1155                 // Only free if structure is unused
1156                 if( !IS_LOCKED(&gDeleteThreads->IsLocked) )
1157                 {
1158                         // Set to dead
1159                         gDeleteThreads->Status = THREAD_STAT_BURIED;
1160                         // Free name
1161                         if( IsHeap(gDeleteThreads->ThreadName) )
1162                                 free(gDeleteThreads->ThreadName);
1163                         // Remove from global list
1164                         if( gDeleteThreads == gAllThreads )
1165                                 gAllThreads = gDeleteThreads->GlobalNext;
1166                         else
1167                                 gDeleteThreads->GlobalPrev->GlobalNext = gDeleteThreads->GlobalNext;
1168                         free( gDeleteThreads );
1169                 }
1170                 gDeleteThreads = thread;
1171         }
1172
1173         // Make sure the current (well, old) thread is marked as de-scheduled
1174         if(Last)        Last->CurCPU = -1;
1175
1176         // No active threads, just take a nap
1177         if(giNumActiveThreads == 0) {
1178                 SHORTREL( &glThreadListLock );
1179                 #if DEBUG_TRACE_TICKETS
1180                 Log("No active threads");
1181                 #endif
1182                 return NULL;
1183         }
1184
1185         #if SCHEDULER_TYPE != SCHED_RR_PRI
1186         // Special case: 1 thread
1187         if(giNumActiveThreads == 1) {
1188                 if( gActiveThreads->CurCPU == -1 )
1189                         gActiveThreads->CurCPU = CPU;
1190
1191                 SHORTREL( &glThreadListLock );
1192
1193                 if( gActiveThreads->CurCPU == CPU )
1194                         return gActiveThreads;
1195
1196                 return NULL;    // CPU has nothing to do
1197         }
1198         #endif
1199
1200         // Allow the old thread to be scheduled again
1201         if( Last ) {
1202                 if( Last->Status == THREAD_STAT_ACTIVE ) {
1203                         #if SCHEDULER_TYPE == SCHED_LOTTERY
1204                         giFreeTickets += caiTICKET_COUNTS[ Last->Priority ];
1205                         # if DEBUG_TRACE_TICKETS
1206                         LogF("Log: CPU%i released %p (%i %s) into the pool (%i [+%i] tickets in pool)\n",
1207                                 CPU, Last, Last->TID, Last->ThreadName, giFreeTickets,
1208                                 caiTICKET_COUNTS[ Last->Priority ]);
1209                         # endif
1210                         #endif
1211                 }
1212                 #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
1213                 else
1214                         LogF("Log: CPU%i released %p (%i %s)->Status = %i (Released,not in pool)\n",
1215                                 CPU, Last, Last->TID, Last->ThreadName, Last->Status);
1216                 #endif
1217                 Last->CurCPU = -1;
1218         }
1219
1220         // ---
1221         // Lottery Scheduler
1222         // ---
1223         #if SCHEDULER_TYPE == SCHED_LOTTERY
1224         {
1225                  int    ticket, number;
1226                 # if 1
1227                 number = 0;
1228                 for(thread = gActiveThreads; thread; thread = thread->Next) {
1229                         if(thread->CurCPU >= 0) continue;
1230                         if(thread->Status != THREAD_STAT_ACTIVE)
1231                                 Panic("Bookkeeping fail - %p %i(%s) is on the active queue with a status of %i",
1232                                         thread, thread->TID, thread->ThreadName, thread->Status);
1233                         if(thread->Next == thread) {
1234                                 Panic("Bookkeeping fail - %p %i(%s) loops back on itself",
1235                                         thread, thread->TID, thread->ThreadName, thread->Status);
1236                         }
1237                         number += caiTICKET_COUNTS[ thread->Priority ];
1238                 }
1239                 if(number != giFreeTickets) {
1240                         Panic("Bookkeeping fail (giFreeTickets(%i) != number(%i)) - CPU%i",
1241                                 giFreeTickets, number, CPU);
1242                 }
1243                 # endif
1244
1245                 // No free tickets (all tasks delegated to cores)
1246                 if( giFreeTickets == 0 ) {
1247                         SHORTREL(&glThreadListLock);
1248                         return NULL;
1249                 }
1250
1251                 // Get the ticket number
1252                 ticket = number = rand() % giFreeTickets;
1253
1254                 // Find the next thread
1255                 for(thread=gActiveThreads;thread;thread=thread->Next)
1256                 {
1257                         if(thread->CurCPU >= 0) continue;
1258                         if( caiTICKET_COUNTS[ thread->Priority ] > number)      break;
1259                         number -= caiTICKET_COUNTS[ thread->Priority ];
1260                 }
1261
1262                 // If we didn't find a thread, something went wrong
1263                 if(thread == NULL)
1264                 {
1265                         number = 0;
1266                         for(thread=gActiveThreads;thread;thread=thread->Next) {
1267                                 if(thread->CurCPU >= 0) continue;
1268                                 number += caiTICKET_COUNTS[ thread->Priority ];
1269                         }
1270                         Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)",
1271                                 giFreeTickets, number);
1272                 }
1273
1274                 giFreeTickets -= caiTICKET_COUNTS[ thread->Priority ];
1275                 # if DEBUG_TRACE_TICKETS
1276                 LogF("Log: CPU%i allocated %p (%i %s), (%i [-%i] tickets in pool), \n",
1277                         CPU, thread, thread->TID, thread->ThreadName,
1278                         giFreeTickets, caiTICKET_COUNTS[ thread->Priority ]);
1279                 # endif
1280         }
1281
1282         // ---
1283         // Priority based round robin scheduler
1284         // ---
1285         #elif SCHEDULER_TYPE == SCHED_RR_PRI
1286         {
1287                  int    i;
1288                 for( i = 0; i < MIN_PRIORITY + 1; i ++ )
1289                 {
1290                         for(thread = gaActiveThreads[i]; thread; thread = thread->Next)
1291                         {
1292                                 if( thread->CurCPU == -1 )      break;
1293                         }
1294                         // If we fall onto the same queue again, special handling is
1295                         // needed
1296                         if( Last && Last->Status == THREAD_STAT_ACTIVE && i == Last->Priority ) {
1297                                 tThread *savedThread = thread;
1298
1299                                 // Find the next unscheduled thread in the list
1300                                 for( thread = Last->Next; thread; thread = thread->Next )
1301                                 {
1302                                         if( thread->CurCPU == -1 )      break;
1303                                 }
1304                                 // If we don't find anything after, just use the one
1305                                 // found above.
1306                                 if( !thread )   thread = savedThread;
1307                         }
1308                         // Found a thread? Schedule it!
1309                         if( thread )    break;
1310                 }
1311
1312                 // Anything to do?
1313                 if( !thread ) {
1314                         SHORTREL(&glThreadListLock);
1315                         return NULL;
1316                 }
1317                 if( thread->Status != THREAD_STAT_ACTIVE ) {
1318                         LogF("Oops, Thread %i (%s) is not active\n", thread->TID, thread->ThreadName);
1319                 }
1320         }
1321         #elif SCHEDULER_TYPE == SCHED_RR_SIM
1322         {
1323                 // Find the next unscheduled thread in the list
1324                 for( thread = Last->Next; thread; thread = thread->Next )
1325                 {
1326                         if( thread->CurCPU == -1 )      break;
1327                 }
1328                 // If we don't find anything after, search from the beginning
1329                 if( !thread )
1330                 {
1331                         for(thread = gActiveThreads; thread; thread = thread->Next)
1332                         {
1333                                 if( thread->CurCPU == -1 )      break;
1334                         }
1335                 }
1336
1337                 // Anything to do?
1338                 if( !thread ) {
1339                         SHORTREL(&glThreadListLock);
1340                         return NULL;
1341                 }
1342         }
1343         #else
1344         # error "Unimplemented scheduling algorithm"
1345         #endif
1346
1347         // Make the new thread non-schedulable
1348         thread->CurCPU = CPU;
1349         thread->Remaining = thread->Quantum;
1350
1351         SHORTREL( &glThreadListLock );
1352
1353         return thread;
1354 }
1355
1356 // Acquire mutex (see mutex.h for documentation)
1357 int Mutex_Acquire(tMutex *Mutex)
1358 {
1359         tThread *us = Proc_GetCurThread();
1360
1361         // Get protector
1362         SHORTLOCK( &Mutex->Protector );
1363
1364         //Log("Mutex_Acquire: (%p)", Mutex);
1365
1366         // Check if the lock is already held
1367         if( Mutex->Owner ) {
1368                 SHORTLOCK( &glThreadListLock );
1369                 // - Remove from active list
1370                 us = Threads_RemActive();
1371                 us->Next = NULL;
1372                 // - Mark as sleeping
1373                 us->Status = THREAD_STAT_MUTEXSLEEP;
1374                 us->WaitPointer = Mutex;
1375
1376                 // - Add to waiting
1377                 if(Mutex->LastWaiting) {
1378                         Mutex->LastWaiting->Next = us;
1379                         Mutex->LastWaiting = us;
1380                 }
1381                 else {
1382                         Mutex->Waiting = us;
1383                         Mutex->LastWaiting = us;
1384                 }
1385
1386                 #if DEBUG_TRACE_STATE
1387                 Log("%p (%i %s) waiting on mutex %p",
1388                         us, us->TID, us->ThreadName, Mutex);
1389                 #endif
1390
1391                 #if 0
1392                 {
1393                          int    i = 0;
1394                         tThread *t;
1395                         for( t = Mutex->Waiting; t; t = t->Next, i++ )
1396                                 Log("[%i] (tMutex)%p->Waiting[%i] = %p (%i %s)", us->TID, Mutex, i,
1397                                         t, t->TID, t->ThreadName);
1398                 }
1399                 #endif
1400
1401                 SHORTREL( &glThreadListLock );
1402                 SHORTREL( &Mutex->Protector );
1403                 while(us->Status == THREAD_STAT_MUTEXSLEEP)     Threads_Yield();
1404                 // We're only woken when we get the lock
1405                 us->WaitPointer = NULL;
1406         }
1407         // Ooh, let's take it!
1408         else {
1409                 Mutex->Owner = us;
1410                 SHORTREL( &Mutex->Protector );
1411         }
1412
1413         #if 0
1414         extern tMutex   glPhysAlloc;
1415         if( Mutex != &glPhysAlloc )
1416                 LogF("Mutex %p taken by %i %p\n", Mutex, us->TID, __builtin_return_address(0));
1417         #endif
1418
1419         return 0;
1420 }
1421
1422 // Release a mutex
1423 void Mutex_Release(tMutex *Mutex)
1424 {
1425         SHORTLOCK( &Mutex->Protector );
1426         //Log("Mutex_Release: (%p)", Mutex);
1427         if( Mutex->Waiting ) {
1428                 Mutex->Owner = Mutex->Waiting;  // Set owner
1429                 Mutex->Waiting = Mutex->Waiting->Next;  // Next!
1430                 // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
1431                 // 2010-10-02 21:50 - Comemerating the death of the longest single
1432                 //                    blocker in the Acess2 history. REMEMBER TO
1433                 //                    FUCKING MAINTAIN YOUR FUCKING LISTS DIPWIT
1434                 if( Mutex->LastWaiting == Mutex->Owner )
1435                         Mutex->LastWaiting = NULL;
1436
1437                 // Wake new owner
1438                 SHORTLOCK( &glThreadListLock );
1439                 if( Mutex->Owner->Status != THREAD_STAT_ACTIVE )
1440                         Threads_AddActive(Mutex->Owner);
1441                 SHORTREL( &glThreadListLock );
1442         }
1443         else {
1444                 Mutex->Owner = NULL;
1445         }
1446         SHORTREL( &Mutex->Protector );
1447
1448         #if 0
1449         extern tMutex   glPhysAlloc;
1450         if( Mutex != &glPhysAlloc )
1451                 LogF("Mutex %p released by %i %p\n", Mutex, Threads_GetTID(), __builtin_return_address(0));
1452         #endif
1453 }
1454
1455 // Check if a mutex is locked
1456 int Mutex_IsLocked(tMutex *Mutex)
1457 {
1458         return Mutex->Owner != NULL;
1459 }
1460
1461 //
1462 // Initialise a semaphore
1463 //
1464 void Semaphore_Init(tSemaphore *Sem, int Value, int MaxValue, const char *Module, const char *Name)
1465 {
1466         memset(Sem, 0, sizeof(tSemaphore));
1467         Sem->Value = Value;
1468         Sem->ModName = Module;
1469         Sem->Name = Name;
1470         Sem->MaxValue = MaxValue;
1471 }
1472 //
1473 // Wait for items to be avaliable
1474 //
1475 int Semaphore_Wait(tSemaphore *Sem, int MaxToTake)
1476 {
1477         tThread *us;
1478          int    taken;
1479         if( MaxToTake < 0 ) {
1480                 Log_Warning("Threads", "Semaphore_Wait: User bug - MaxToTake(%i) < 0, Sem=%p(%s)",
1481                         MaxToTake, Sem, Sem->Name);
1482         }
1483
1484         SHORTLOCK( &Sem->Protector );
1485
1486         // Check if there's already items avaliable
1487         if( Sem->Value > 0 ) {
1488                 // Take what we need
1489                 if( MaxToTake && Sem->Value > MaxToTake )
1490                         taken = MaxToTake;
1491                 else
1492                         taken = Sem->Value;
1493                 Sem->Value -= taken;
1494         }
1495         else
1496         {
1497                 SHORTLOCK( &glThreadListLock );
1498
1499                 // - Remove from active list
1500                 us = Threads_RemActive();
1501                 us->Next = NULL;
1502                 // - Mark as sleeping
1503                 us->Status = THREAD_STAT_SEMAPHORESLEEP;
1504                 us->WaitPointer = Sem;
1505                 us->RetStatus = MaxToTake;      // Use RetStatus as a temp variable
1506
1507                 // - Add to waiting
1508                 if(Sem->LastWaiting) {
1509                         Sem->LastWaiting->Next = us;
1510                         Sem->LastWaiting = us;
1511                 }
1512                 else {
1513                         Sem->Waiting = us;
1514                         Sem->LastWaiting = us;
1515                 }
1516
1517                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1518                 Log("%p (%i %s) waiting on semaphore %p %s:%s",
1519                         us, us->TID, us->ThreadName,
1520                         Sem, Sem->ModName, Sem->Name);
1521                 #endif
1522
1523                 SHORTREL( &Sem->Protector );    // Release first to make sure it is released
1524                 SHORTREL( &glThreadListLock );
1525                 while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
1526                 // We're only woken when there's something avaliable (or a signal arrives)
1527                 us->WaitPointer = NULL;
1528
1529                 taken = us->RetStatus;
1530
1531                 // Get the lock again
1532                 SHORTLOCK( &Sem->Protector );
1533         }
1534
1535         // While there is space, and there are thread waiting
1536         // wake the first thread and give it what it wants (or what's left)
1537         while( (Sem->MaxValue == 0 || Sem->Value < Sem->MaxValue) && Sem->Signaling )
1538         {
1539                  int    given;
1540                 tThread *toWake = Sem->Signaling;
1541
1542                 Sem->Signaling = Sem->Signaling->Next;
1543                 // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
1544                 if( Sem->Signaling == NULL )
1545                         Sem->LastSignaling = NULL;
1546
1547                 // Figure out how much to give
1548                 if( toWake->RetStatus && Sem->Value + toWake->RetStatus < Sem->MaxValue )
1549                         given = toWake->RetStatus;
1550                 else
1551                         given = Sem->MaxValue - Sem->Value;
1552                 Sem->Value -= given;
1553
1554
1555                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1556                 Log("%p (%i %s) woken by wait on %p %s:%s",
1557                         toWake, toWake->TID, toWake->ThreadName,
1558                         Sem, Sem->ModName, Sem->Name);
1559                 #endif
1560
1561                 // Save the number we gave to the thread's status
1562                 toWake->RetStatus = given;
1563
1564                 // Wake the sleeper
1565                 SHORTLOCK( &glThreadListLock );
1566                 if( toWake->Status != THREAD_STAT_ACTIVE )
1567                         Threads_AddActive(toWake);
1568                 SHORTREL( &glThreadListLock );
1569         }
1570         SHORTREL( &Sem->Protector );
1571
1572         return taken;
1573 }
1574
1575 //
1576 // Add items to a semaphore
1577 //
1578 int Semaphore_Signal(tSemaphore *Sem, int AmmountToAdd)
1579 {
1580          int    given;
1581          int    added;
1582
1583         if( AmmountToAdd < 0 ) {
1584                 Log_Warning("Threads", "Semaphore_Signal: User bug - AmmountToAdd(%i) < 0, Sem=%p(%s)",
1585                         AmmountToAdd, Sem, Sem->Name);
1586         }
1587         SHORTLOCK( &Sem->Protector );
1588
1589         // Check if we have to block
1590         if( Sem->MaxValue && Sem->Value == Sem->MaxValue )
1591         {
1592                 tThread *us;
1593                 #if 0
1594                 Log_Debug("Threads", "Semaphore_Signal: IDLE Sem = %s:%s", Sem->ModName, Sem->Name);
1595                 Log_Debug("Threads", "Semaphore_Signal: Sem->Value(%i) == Sem->MaxValue(%i)", Sem->Value, Sem->MaxValue);
1596                 #endif
1597
1598                 SHORTLOCK( &glThreadListLock );
1599                 // - Remove from active list
1600                 us = Threads_RemActive();
1601                 us->Next = NULL;
1602                 // - Mark as sleeping
1603                 us->Status = THREAD_STAT_SEMAPHORESLEEP;
1604                 us->WaitPointer = Sem;
1605                 us->RetStatus = AmmountToAdd;   // Use RetStatus as a temp variable
1606
1607                 // - Add to waiting
1608                 if(Sem->LastSignaling) {
1609                         Sem->LastSignaling->Next = us;
1610                         Sem->LastSignaling = us;
1611                 }
1612                 else {
1613                         Sem->Signaling = us;
1614                         Sem->LastSignaling = us;
1615                 }
1616
1617                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1618                 Log("%p (%i %s) signaling semaphore %p %s:%s",
1619                         us, us->TID, us->ThreadName,
1620                         Sem, Sem->ModName, Sem->Name);
1621                 #endif
1622
1623                 SHORTREL( &glThreadListLock );
1624                 SHORTREL( &Sem->Protector );
1625                 while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
1626                 // We're only woken when there's something avaliable
1627                 us->WaitPointer = NULL;
1628
1629                 added = us->RetStatus;
1630
1631                 // Get the lock again
1632                 SHORTLOCK( &Sem->Protector );
1633         }
1634         // Non blocking
1635         else
1636         {
1637                 // Figure out how much we need to take off
1638                 if( Sem->MaxValue && Sem->Value + AmmountToAdd > Sem->MaxValue)
1639                         added = Sem->MaxValue - Sem->Value;
1640                 else
1641                         added = AmmountToAdd;
1642                 Sem->Value += added;
1643         }
1644
1645         // While there are items avaliable, and there are thread waiting
1646         // wake the first thread and give it what it wants (or what's left)
1647         while( Sem->Value && Sem->Waiting )
1648         {
1649                 tThread *toWake = Sem->Waiting;
1650
1651                 // Remove thread from list (double ended, so clear LastWaiting if needed)
1652                 Sem->Waiting = Sem->Waiting->Next;
1653                 if( Sem->Waiting == NULL )
1654                         Sem->LastWaiting = NULL;
1655
1656                 // Figure out how much to give to woken thread
1657                 // - Requested count is stored in ->RetStatus
1658                 if( toWake->RetStatus && Sem->Value > toWake->RetStatus )
1659                         given = toWake->RetStatus;
1660                 else
1661                         given = Sem->Value;
1662                 Sem->Value -= given;
1663
1664                 // Save the number we gave to the thread's status
1665                 toWake->RetStatus = given;
1666
1667                 if(toWake->bInstrTrace)
1668                         Log("%s(%i) given %i from %p", toWake->ThreadName, toWake->TID, given, Sem);
1669                 #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
1670                 Log("%p (%i %s) woken by signal on %p %s:%s",
1671                         toWake, toWake->TID, toWake->ThreadName,
1672                         Sem, Sem->ModName, Sem->Name);
1673                 #endif
1674
1675                 // Wake the sleeper
1676                 SHORTLOCK( &glThreadListLock );
1677                 if( toWake->Status != THREAD_STAT_ACTIVE )
1678                         Threads_AddActive(toWake);
1679                 else
1680                         Warning("Thread %p (%i %s) is already awake", toWake, toWake->TID, toWake->ThreadName);
1681                 SHORTREL( &glThreadListLock );
1682         }
1683         SHORTREL( &Sem->Protector );
1684
1685         return added;
1686 }
1687
1688 //
1689 // Get the current value of a semaphore
1690 //
1691 int Semaphore_GetValue(tSemaphore *Sem)
1692 {
1693         return Sem->Value;
1694 }
1695
1696 // === EXPORTS ===
1697 EXPORT(Threads_GetUID);
1698 EXPORT(Threads_GetGID);
1699 EXPORT(Mutex_Acquire);
1700 EXPORT(Mutex_Release);
1701 EXPORT(Mutex_IsLocked);
1702 EXPORT(Semaphore_Init);
1703 EXPORT(Semaphore_Wait);
1704 EXPORT(Semaphore_Signal);