X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Fthreads.c;h=aa550ab74389a1e6bb44b0e7178109e3d0c97485;hb=126cef9a37b4859e3d6555760a5bbaa308a715d6;hp=5d8e40139429bd3af9364114bf4d30cb5cf37a44;hpb=15999a03acd4083fb2618c92bebbc557813c5084;p=tpg%2Facess2.git diff --git a/Kernel/threads.c b/Kernel/threads.c index 5d8e4013..aa550ab7 100644 --- a/Kernel/threads.c +++ b/Kernel/threads.c @@ -69,15 +69,15 @@ tThread gThreadZero = { // --- Locks --- tShortSpinlock glThreadListLock; ///\note NEVER use a heap function while locked // --- Current State --- -volatile int giNumActiveThreads = 0; -volatile int giFreeTickets = 0; -volatile Uint giNextTID = 1; +volatile int giNumActiveThreads = 0; // Number of threads on the active queue +volatile int giFreeTickets = 0; // Number of tickets held by non-scheduled threads +volatile Uint giNextTID = 1; // Next TID to allocate // --- Thread Lists --- tThread *gAllThreads = NULL; // All allocated threads tThread *gActiveThreads = NULL; // Currently Running Threads tThread *gSleepingThreads = NULL; // Sleeping Threads tThread *gDeleteThreads = NULL; // Threads to delete - int giNumCPUs = 1; + int giNumCPUs = 1; // Number of CPUs // === CODE === /** @@ -90,7 +90,8 @@ void Threads_Init(void) // Create Initial Task gActiveThreads = &gThreadZero; - //giFreeTickets = gThreadZero.NumTickets; + gAllThreads = &gThreadZero; + //giFreeTickets = gThreadZero.NumTickets; // Not needed, as ThreadZero is scheduled giNumActiveThreads = 1; Proc_Start(); @@ -99,12 +100,17 @@ void Threads_Init(void) /** * \fn void Threads_SetName(char *NewName) * \brief Sets the current thread's name + * \param NewName New name for the thread + * \return Boolean Failure */ int Threads_SetName(char *NewName) { tThread *cur = Proc_GetCurThread(); char *oldname = cur->ThreadName; + // NOTE: There is a possibility of non-thread safety here + // A thread could read the current name pointer before it is zeroed + cur->ThreadName = NULL; if( IsHeap(oldname) ) free( oldname ); @@ -116,31 +122,40 @@ int Threads_SetName(char *NewName) /** * \fn char *Threads_GetName(int ID) * \brief Gets a thread's name + * \param ID Thread ID (-1 indicates current thread) + * \return Pointer to name + * \retval NULL Failure */ -char *Threads_GetName(int ID) +char *Threads_GetName(tTID ID) { if(ID == -1) { return Proc_GetCurThread()->ThreadName; } - // TODO: Find a thread and get its name - return NULL; + return Threads_GetThread(ID)->ThreadName; } /** * \fn void Threads_SetTickets(tThread *Thread, int Num) * \brief Sets the 'priority' of a task + * \param Thread Thread to update ticket count (NULL means current thread) + * \param Num New ticket count (must be >= 0, clipped to \a MAX_TICKETS) */ void Threads_SetTickets(tThread *Thread, int Num) { - if(Thread == NULL) - Thread = Proc_GetCurThread(); + // Get current thread + if(Thread == NULL) Thread = Proc_GetCurThread(); + // Bounds checking if(Num < 0) return; if(Num > MAX_TICKETS) Num = MAX_TICKETS; + // If this isn't the current thread, we need to lock if( Thread != Proc_GetCurThread() ) { SHORTLOCK( &glThreadListLock ); giFreeTickets -= Thread->NumTickets - Num; Thread->NumTickets = Num; + #if DEBUG_TRACE_TICKETS + Log("Threads_SetTickets: new giFreeTickets = %i", giFreeTickets); + #endif SHORTREL( &glThreadListLock ); } else @@ -149,6 +164,9 @@ void Threads_SetTickets(tThread *Thread, int Num) /** * \fn tThread *Threads_CloneTCB(Uint *Err, Uint Flags) + * \brief Clone the TCB of the current thread + * \param Err Error pointer + * \param Flags Flags for something... (What is this for?) */ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) { @@ -156,6 +174,7 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) int i; cur = Proc_GetCurThread(); + // Allocate and duplicate new = malloc(sizeof(tThread)); if(new == NULL) { *Err = -ENOMEM; @@ -166,7 +185,7 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) new->CurCPU = -1; new->Next = NULL; memset( &new->IsLocked, 0, sizeof(new->IsLocked)); - new->Status = THREAD_STAT_ACTIVE; + new->Status = THREAD_STAT_PREINIT; new->RetStatus = 0; // Get Thread ID @@ -221,24 +240,27 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags) } /** - * \fn Uint *Threads_GetCfgPtr(int Id) + * \brief Get a configuration pointer from the Per-Thread data area + * \param ID Config slot ID + * \return Pointer at ID */ -Uint *Threads_GetCfgPtr(int Id) +Uint *Threads_GetCfgPtr(int ID) { - if(Id < 0 || Id >= NUM_CFG_ENTRIES) { - Warning("Threads_GetCfgPtr: Index %i is out of bounds", Id); + if(ID < 0 || ID >= NUM_CFG_ENTRIES) { + Warning("Threads_GetCfgPtr: Index %i is out of bounds", ID); return NULL; } - return &Proc_GetCurThread()->Config[Id]; + return &Proc_GetCurThread()->Config[ID]; } /** - * \fn tTID Threads_WaitTID(int TID, int *status) * \brief Wait for a task to change state + * \param TID Thread ID to wait on (-1: Any child thread, 0: Any Child/Sibling, <-1: -PID) + * \param Status Thread return status * \return TID of child that changed state */ -int Threads_WaitTID(int TID, int *status) +tTID Threads_WaitTID(int TID, int *Status) { // Any Child if(TID == -1) { @@ -262,8 +284,9 @@ int Threads_WaitTID(int TID, int *status) if(TID > 0) { tThread *t = Threads_GetThread(TID); int initStatus = t->Status; - int ret; + tTID ret; + // Wait for the thread to die! if(initStatus != THREAD_STAT_ZOMBIE) { // TODO: Handle child also being suspended if wanted while(t->Status != THREAD_STAT_ZOMBIE) { @@ -273,21 +296,22 @@ int Threads_WaitTID(int TID, int *status) } } + // Set return status Log_Debug("Threads", "%i waiting for %i, t->Status = %i", Threads_GetTID(), t->TID, t->Status); - ret = t->RetStatus; + ret = t->TID; switch(t->Status) { case THREAD_STAT_ZOMBIE: // Kill the thread t->Status = THREAD_STAT_DEAD; // TODO: Child return value? - if(status) *status = 0; + if(Status) *Status = t->RetStatus; // add to delete queue Threads_AddToDelete( t ); break; default: - if(status) *status = -1; + if(Status) *Status = -1; break; } return ret; @@ -297,9 +321,9 @@ int Threads_WaitTID(int TID, int *status) } /** - * \fn tThread *Threads_GetThread(Uint TID) * \brief Gets a thread given its TID * \param TID Thread ID + * \return Thread pointer */ tThread *Threads_GetThread(Uint TID) { @@ -313,17 +337,20 @@ tThread *Threads_GetThread(Uint TID) if(thread->TID == TID) return thread; } + + Log("Unable to find TID %i on main list\n", TID); return NULL; } /** - * \fn void Threads_AddToDelete(tThread *Thread) * \brief Adds a thread to the delete queue + * \param Thread Thread to delete */ void Threads_AddToDelete(tThread *Thread) { // Add to delete queue + // TODO: Is locking needed? if(gDeleteThreads) { Thread->Next = gDeleteThreads; gDeleteThreads = Thread; @@ -334,8 +361,13 @@ void Threads_AddToDelete(tThread *Thread) } /** - * \fn tThread *Threads_int_GetPrev(tThread **List, tThread *Thread) * \brief Gets the previous entry in a thead linked list + * \param List Pointer to the list head + * \param Thread Thread to find + * \return Thread before \a Thread on \a List + * \note This uses a massive hack of assuming that the first field in the + * structure is the .Next pointer. By doing this, we can return \a List + * as a (tThread*) and simplify other code. */ tThread *Threads_int_GetPrev(tThread **List, tThread *Thread) { @@ -343,7 +375,9 @@ tThread *Threads_int_GetPrev(tThread **List, tThread *Thread) // First Entry if(*List == Thread) { return (tThread*)List; - } else { + } + // Or not + else { for(ret = *List; ret->Next && ret->Next != Thread; ret = ret->Next @@ -357,8 +391,9 @@ tThread *Threads_int_GetPrev(tThread **List, tThread *Thread) } /** - * \fn void Threads_Exit(int TID, int Status) - * \brief Exit the current process + * \brief Exit the current process (or another?) + * \param TID Thread ID to kill + * \param Status Exit status */ void Threads_Exit(int TID, int Status) { @@ -366,9 +401,9 @@ void Threads_Exit(int TID, int Status) Threads_Kill( Proc_GetCurThread(), (Uint)Status & 0xFF ); else Threads_Kill( Threads_GetThread(TID), (Uint)Status & 0xFF ); + // Halt forever, just in case - for(;;) - HALT(); + for(;;) HALT(); } /** @@ -382,10 +417,11 @@ void Threads_Kill(tThread *Thread, int Status) tThread *prev; tMsg *msg; - // Kill all children + // TODO: Kill all children #if 0 { tThread *child; + // TODO: I should keep a .Parent pointer, and a .Children list for(child = gActiveThreads; child; child = child->Next) @@ -408,8 +444,8 @@ void Threads_Kill(tThread *Thread, int Status) prev = Threads_int_GetPrev( &gActiveThreads, Thread ); if(!prev) { Warning("Proc_Exit - Current thread is not on the active queue"); - SHORTREL( &Thread->IsLocked ); SHORTREL( &glThreadListLock ); + SHORTREL( &Thread->IsLocked ); return; } @@ -417,14 +453,16 @@ void Threads_Kill(tThread *Thread, int Status) while( Thread->Messages ) { msg = Thread->Messages->Next; - free( Thread->Messages ); + free( Thread->Messages ); // BIG NO-NO Thread->Messages = msg; } + // Ensure that we are not rescheduled Thread->Remaining = 0; // Clear Remaining Quantum Thread->Quantum = 0; // Clear Quantum to indicate dead thread prev->Next = Thread->Next; // Remove from active + // Update bookkeeping giNumActiveThreads --; if( Thread != Proc_GetCurThread() ) giFreeTickets -= Thread->NumTickets; @@ -432,7 +470,7 @@ void Threads_Kill(tThread *Thread, int Status) // Save exit status Thread->RetStatus = Status; - // Don't Zombie if we are being killed as part of a tree + // Don't Zombie if we are being killed because our parent is if(Status == -1) { Thread->Status = THREAD_STAT_DEAD; @@ -446,20 +484,25 @@ void Threads_Kill(tThread *Thread, int Status) Log("Thread %i went *hurk* (%i)", Thread->TID, Thread->Status); // Release spinlocks - SHORTREL( &Thread->IsLocked ); SHORTREL( &glThreadListLock ); + SHORTREL( &Thread->IsLocked ); // TODO: We may not actually be released... - if(Status != -1) HALT(); + // And, reschedule + if(Status != -1) { + for( ;; ) + HALT(); + } } /** - * \fn void Threads_Yield(void) - * \brief Yield remainder of timeslice + * \brief Yield remainder of the current thread's timeslice */ void Threads_Yield(void) { - Proc_GetCurThread()->Remaining = 0; - HALT(); + tThread *thread = Proc_GetCurThread(); + thread->Remaining = 0; + //while(thread->Remaining == 0) + HALT(); } /** @@ -470,8 +513,6 @@ void Threads_Sleep(void) { tThread *cur = Proc_GetCurThread(); - //Log_Log("Threads", "%i going to sleep", cur->TID); - // Acquire Spinlock SHORTLOCK( &glThreadListLock ); @@ -483,13 +524,13 @@ void Threads_Sleep(void) // Remove us from running queue Threads_RemActive(); + // Mark thread as sleeping + cur->Status = THREAD_STAT_SLEEPING; // Add to Sleeping List (at the top) cur->Next = gSleepingThreads; gSleepingThreads = cur; - // Mark thread as sleeping - cur->Status = THREAD_STAT_SLEEPING; #if DEBUG_TRACE_STATE Log("Threads_Sleep: %p (%i %s) sleeping", cur, cur->TID, cur->ThreadName); @@ -507,7 +548,7 @@ void Threads_Sleep(void) * \brief Wakes a sleeping/waiting thread up * \param Thread Thread to wake * \return Boolean Failure (Returns ERRNO) - * \note Should be called with the scheduler lock held + * \warning This should ONLY be called with task switches disabled */ int Threads_Wake(tThread *Thread) { @@ -522,24 +563,18 @@ int Threads_Wake(tThread *Thread) Log("Thread_Wake: Waking awake thread (%i)", Thread->TID); return -EALREADY; - case THREAD_STAT_SLEEPING: // TODO: Comment better + case THREAD_STAT_SLEEPING: + SHORTLOCK( &glThreadListLock ); // Remove from sleeping queue prev = Threads_int_GetPrev(&gSleepingThreads, Thread); prev->Next = Thread->Next; - // Add to active queue - Thread->Next = gActiveThreads; - gActiveThreads = Thread; - // Update bookkeeping - giNumActiveThreads ++; - giFreeTickets += Thread->NumTickets; - #if DEBUG_TRACE_TICKETS - Log("Threads_Wake: new giFreeTickets = %i", giFreeTickets); - #endif - Thread->CurCPU = -1; - Thread->Status = THREAD_STAT_ACTIVE; + + Threads_AddActive( Thread ); + #if DEBUG_TRACE_STATE Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName); #endif + SHORTREL( &glThreadListLock ); return -EOK; case THREAD_STAT_WAITING: @@ -567,27 +602,50 @@ int Threads_WakeTID(tTID TID) int ret; if(!thread) return -ENOENT; - SHORTLOCK( &glThreadListLock ); ret = Threads_Wake( thread ); - SHORTREL( &glThreadListLock ); + //Log_Debug("Threads", "TID %i woke %i (%p)", Threads_GetTID(), TID, thread); return ret; } /** - * \fn void Threads_AddActive(tThread *Thread) * \brief Adds a thread to the active queue */ void Threads_AddActive(tThread *Thread) { SHORTLOCK( &glThreadListLock ); + + #if 1 + { + tThread *t; + for( t = gActiveThreads; t; t = t->Next ) + { + if( t == Thread ) { + Panic("Threads_AddActive: Attempting a double add of TID %i (0x%x)", + Thread->TID, __builtin_return_address(0)); + } + + if(t->Status != THREAD_STAT_ACTIVE) { + Panic("Threads_AddActive: TID %i status != THREAD_STAT_ACTIVE", + Thread->TID); + } + } + } + #endif + // Add to active list Thread->Next = gActiveThreads; gActiveThreads = Thread; + // Set state + Thread->Status = THREAD_STAT_ACTIVE; + Thread->CurCPU = -1; + // Update bookkeeping giNumActiveThreads ++; giFreeTickets += Thread->NumTickets; + #if DEBUG_TRACE_TICKETS - Log("Threads_AddActive: new giFreeTickets = %i", giFreeTickets); + Log("Threads_AddActive: %p %i (%s) added, new giFreeTickets = %i", + Thread, Thread->TID, Thread->ThreadName, giFreeTickets); #endif SHORTREL( &glThreadListLock ); } @@ -600,12 +658,30 @@ void Threads_AddActive(tThread *Thread) tThread *Threads_RemActive(void) { tThread *ret = Proc_GetCurThread(); - tThread *prev = Threads_int_GetPrev(&gActiveThreads, ret); - if(!prev) return NULL; + tThread *prev; + + SHORTLOCK( &glThreadListLock ); + + prev = Threads_int_GetPrev(&gActiveThreads, ret); + if(!prev) { + SHORTREL( &glThreadListLock ); + return NULL; + } + ret->Remaining = 0; ret->CurCPU = -1; + prev->Next = ret->Next; giNumActiveThreads --; + // no need to decrement tickets, scheduler did it for us + + #if DEBUG_TRACE_TICKETS + Log("Threads_RemActive: %p %i (%s) removed, giFreeTickets = %i", + ret, ret->TID, ret->ThreadName, giFreeTickets); + #endif + + SHORTREL( &glThreadListLock ); + return ret; } @@ -700,18 +776,20 @@ int Threads_SetGID(Uint *Errno, tGID ID) /** * \fn void Threads_Dump(void) - * \brief Dums a list of currently running threads + * \brief Dumps a list of currently running threads */ void Threads_Dump(void) { tThread *thread; - Log("Active Threads:"); + Log("--- Thread Dump ---"); + Log("Active Threads: (%i reported)", giNumActiveThreads); for(thread=gActiveThreads;thread;thread=thread->Next) { Log(" %i (%i) - %s (CPU %i)", thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU); - Log(" State: %i", thread->Status); + if(thread->Status != THREAD_STAT_ACTIVE) + Log(" ERROR State (%i) != THREAD_STAT_ACTIVE (%i)", thread->Status, THREAD_STAT_ACTIVE); Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum); Log(" KStack 0x%x", thread->KernelStack); } @@ -721,14 +799,31 @@ void Threads_Dump(void) { Log(" %i (%i) - %s (CPU %i)", thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU); - Log(" State: %i", thread->Status); + Log(" State %i", thread->Status); + Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum); + Log(" KStack 0x%x", thread->KernelStack); + } +} +/** + * \fn void Threads_Dump(void) + */ +void Threads_DumpActive(void) +{ + tThread *thread; + + Log("Active Threads:"); + for(thread=gActiveThreads;thread;thread=thread->Next) + { + Log(" %i (%i) - %s (CPU %i)", + thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU); + if(thread->Status != THREAD_STAT_ACTIVE) + Log(" ERROR State (%i) != THREAD_STAT_ACTIVE (%i)", thread->Status, THREAD_STAT_ACTIVE); Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum); Log(" KStack 0x%x", thread->KernelStack); } } /** - * \fn tThread *Threads_GetNextToRun(int CPU, tThread *Last) * \brief Gets the next thread to run * \param CPU Current CPU * \param Last The thread the CPU was running @@ -739,10 +834,15 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last) int ticket; int number; + // If this CPU has the lock, we must let it complete + if( CPU_HAS_LOCK( &glThreadListLock ) ) + return Last; + // Lock thread list SHORTLOCK( &glThreadListLock ); // Clear Delete Queue + // - I should probably put this in a worker thread to avoid calling free() in the scheduler while(gDeleteThreads) { thread = gDeleteThreads->Next; @@ -775,9 +875,12 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last) if(giNumActiveThreads == 1) { if( gActiveThreads->CurCPU == -1 ) gActiveThreads->CurCPU = CPU; + SHORTREL( &glThreadListLock ); + if( gActiveThreads->CurCPU == CPU ) return gActiveThreads; + return NULL; // CPU has nothing to do } @@ -792,15 +895,27 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last) } #if DEBUG_TRACE_TICKETS else - LogF(" %p (%s)->Status = %i\n", Last, Last->ThreadName, Last->Status); + LogF(" CPU %i released %p (%s)->Status = %i (Released)\n", + CPU, Last, Last->ThreadName, Last->Status); #endif Last->CurCPU = -1; } + #if DEBUG_TRACE_TICKETS + //Threads_DumpActive(); + #endif + #if 1 number = 0; - for(thread=gActiveThreads;thread;thread=thread->Next) { + for(thread = gActiveThreads; thread; thread = thread->Next) { if(thread->CurCPU >= 0) continue; + if(thread->Status != THREAD_STAT_ACTIVE) + Panic("Bookkeeping fail - %p %i(%s) is on the active queue with a status of %i", + thread, thread->TID, thread->ThreadName, thread->Status); + if(thread->Next == thread) { + Panic("Bookkeeping fail - %p %i(%s) loops back on itself", + thread, thread->TID, thread->ThreadName, thread->Status); + } number += thread->NumTickets; } if(number != giFreeTickets) { @@ -904,7 +1019,7 @@ void Mutex_Acquire(tMutex *Mutex) } SHORTREL( &glThreadListLock ); SHORTREL( &Mutex->Protector ); - while(us->Status == THREAD_STAT_OFFSLEEP) HALT(); + while(us->Status == THREAD_STAT_OFFSLEEP) Threads_Yield(); // We're only woken when we get the lock } // Ooh, let's take it! @@ -925,10 +1040,12 @@ void Mutex_Release(tMutex *Mutex) if( Mutex->Waiting ) { Mutex->Owner = Mutex->Waiting; // Set owner Mutex->Waiting = Mutex->Waiting->Next; // Next! + // Wake new owner - Mutex->Owner->Status = THREAD_STAT_ACTIVE; - Threads_AddActive(Mutex->Owner); - Log("Mutex %p Woke %p", Mutex, Mutex->Owner); + SHORTLOCK( &glThreadListLock ); + if( Mutex->Owner->Status != THREAD_STAT_ACTIVE ) + Threads_AddActive(Mutex->Owner); + SHORTREL( &glThreadListLock ); } else { Mutex->Owner = NULL; @@ -947,3 +1064,6 @@ int Mutex_IsLocked(tMutex *Mutex) // === EXPORTS === EXPORT(Threads_GetUID); +EXPORT(Mutex_Acquire); +EXPORT(Mutex_Release); +EXPORT(Mutex_IsLocked);