#include <threads.h>
#include <errno.h>
-#define DEBUG_TRACE_TICKETS 0
+// Configuration
+#define DEBUG_TRACE_TICKETS 0 // Trace ticket counts
+#define DEBUG_TRACE_STATE 0 // Trace state changes (sleep/wake)
+
+// --- Schedulers ---
+#define SCHED_UNDEF 0
+#define SCHED_LOTTERY 1 // Lottery scheduler
+#define SCHED_RR_SIM 2 // Single Queue Round Robin
+#define SCHED_RR_PRI 3 // Multi Queue Round Robin
+// Set scheduler type
+#define SCHEDULER_TYPE SCHED_LOTTERY
// === CONSTANTS ===
#define DEFAULT_QUANTUM 10
-#define DEFAULT_TICKETS 5
-#define MAX_TICKETS 10
+#define DEFAULT_PRIORITY 5
+#define MIN_PRIORITY 10
const enum eConfigTypes cCONFIG_TYPES[] = {
CFGT_HEAPSTR, // e.g. CFG_VFS_CWD
CFGT_INT, // e.g. CFG_VFS_MAXFILES
int Threads_WaitTID(int TID, int *status);
tThread *Threads_GetThread(Uint TID);
void Threads_AddToDelete(tThread *Thread);
-tThread *Threads_int_GetPrev(tThread **List, tThread *Thread);
+tThread *Threads_int_DelFromQueue(tThread **List, tThread *Thread);
void Threads_Exit(int TID, int Status);
void Threads_Kill(tThread *Thread, int Status);
void Threads_Yield(void);
void Threads_Sleep(void);
int Threads_Wake(tThread *Thread);
void Threads_AddActive(tThread *Thread);
+tThread *Threads_RemActive(void);
int Threads_GetPID(void);
int Threads_GetTID(void);
tUID Threads_GetUID(void);
tGID Threads_GetGID(void);
int Threads_SetGID(Uint *Errno, tUID ID);
void Threads_Dump(void);
+void Threads_DumpActive(void);
+void Mutex_Acquire(tMutex *Mutex);
+void Mutex_Release(tMutex *Mutex);
+ int Mutex_IsLocked(tMutex *Mutex);
// === GLOBALS ===
// -- Core Thread --
ThreadName: "ThreadZero", // Name
Quantum: DEFAULT_QUANTUM, // Default Quantum
Remaining: DEFAULT_QUANTUM, // Current Quantum
- NumTickets: DEFAULT_TICKETS // Number of tickets
+ Priority: DEFAULT_PRIORITY // Number of tickets
};
// -- Processes --
// --- Locks ---
-tSpinlock glThreadListLock = 0; ///\note NEVER use a heap function while locked
+tShortSpinlock glThreadListLock; ///\note NEVER use a heap function while locked
// --- Current State ---
-volatile int giNumActiveThreads = 0;
-//volatile int giTotalTickets = 0;
-volatile int giFreeTickets = 0;
-volatile Uint giNextTID = 1;
+volatile int giNumActiveThreads = 0; // Number of threads on the active queue
+volatile Uint giNextTID = 1; // Next TID to allocate
// --- Thread Lists ---
-tThread *gActiveThreads = NULL; // Currently Running Threads
+tThread *gAllThreads = NULL; // All allocated threads
tThread *gSleepingThreads = NULL; // Sleeping Threads
tThread *gDeleteThreads = NULL; // Threads to delete
- int giNumCPUs = 1;
+ int giNumCPUs = 1; // Number of CPUs
+BOOL gaThreads_NoTaskSwitch[MAX_CPUS]; // Disables task switches for each core (Pseudo-IF)
+// --- Scheduler Types ---
+#if SCHEDULER_TYPE == SCHED_LOTTERY
+const int caiTICKET_COUNTS[MIN_PRIORITY+1] = {100,81,64,49,36,25,16,9,4,1,0};
+volatile int giFreeTickets = 0; // Number of tickets held by non-scheduled threads
+tThread *gActiveThreads = NULL; // Currently Running Threads
+#elif SCHEDULER_TYPE == SCHED_RR_SIM
+tThread *gActiveThreads = NULL; // Currently Running Threads
+#elif SCHEDULER_TYPE == SCHED_RR_PRI
+tThread *gaActiveThreads[MIN_PRIORITY+1]; // Active threads for each priority level
+#else
+# error "Unkown scheduler type"
+#endif
// === CODE ===
/**
ArchThreads_Init();
// Create Initial Task
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ gaActiveThreads[gThreadZero.Priority] = &gThreadZero;
+ #else
gActiveThreads = &gThreadZero;
- //giFreeTickets = gThreadZero.NumTickets;
+ #endif
+
+ gAllThreads = &gThreadZero;
giNumActiveThreads = 1;
Proc_Start();
/**
* \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 );
/**
* \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
+ * \fn void Threads_SetPriority(tThread *Thread, int Pri)
+ * \brief Sets the priority of a task
+ * \param Thread Thread to update ticket count (NULL means current thread)
+ * \param Pri New priority
*/
-void Threads_SetTickets(tThread *Thread, int Num)
+void Threads_SetPriority(tThread *Thread, int Pri)
{
- if(Thread == NULL)
- Thread = Proc_GetCurThread();
- if(Num < 0) return;
- if(Num > MAX_TICKETS) Num = MAX_TICKETS;
-
- if( Thread != Proc_GetCurThread() ) {
- LOCK( &glThreadListLock );
- giFreeTickets -= Thread->NumTickets - Num;
- Thread->NumTickets = Num;
- RELEASE( &glThreadListLock );
+ // Get current thread
+ if(Thread == NULL) Thread = Proc_GetCurThread();
+ // Bounds checking
+ // - If < 0, set to lowest priority
+ if(Pri < 0) Pri = MIN_PRIORITY;
+ if(Pri > MIN_PRIORITY) Pri = MIN_PRIORITY;
+
+ // Do we actually have to do anything?
+ if( Pri == Thread->Priority ) return;
+
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ SHORTLOCK( &glThreadListLock );
+ // Remove from old priority
+ Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread );
+ // And add to new
+ Thread->Next = gaActiveThreads[Pri];
+ gaActiveThreads[Pri] = Thread;
+ Thread->Priority = Pri;
+ SHORTREL( &glThreadListLock );
+ #else
+ // If this isn't the current thread, we need to lock
+ if( Thread != Proc_GetCurThread() )
+ {
+ SHORTLOCK( &glThreadListLock );
+
+ #if SCHEDULER_TYPE == SCHED_LOTTERY
+ giFreeTickets -= caiTICKET_COUNTS[Thread->Priority] - caiTICKET_COUNTS[Pri];
+ # if DEBUG_TRACE_TICKETS
+ Log("Threads_SetTickets: new giFreeTickets = %i", giFreeTickets);
+ # endif
+ #endif
+ Thread->Priority = Pri;
+ SHORTREL( &glThreadListLock );
}
else
- Thread->NumTickets = Num;
+ Thread->Priority = Pri;
+ #endif
}
/**
* \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)
{
int i;
cur = Proc_GetCurThread();
+ // Allocate and duplicate
new = malloc(sizeof(tThread));
if(new == NULL) {
*Err = -ENOMEM;
new->CurCPU = -1;
new->Next = NULL;
- new->IsLocked = 0;
- new->Status = THREAD_STAT_ACTIVE;
+ memset( &new->IsLocked, 0, sizeof(new->IsLocked));
+ new->Status = THREAD_STAT_PREINIT;
new->RetStatus = 0;
// Get Thread ID
new->TID = giNextTID++;
- new->PTID = cur->TID;
+ new->Parent = cur;
// Clone Name
new->ThreadName = strdup(cur->ThreadName);
// Set State
new->Remaining = new->Quantum = cur->Quantum;
- new->NumTickets = cur->NumTickets;
+ new->Priority = cur->Priority;
// Set Signal Handlers
new->CurFaultNum = 0;
}
}
+ // Maintain a global list of threads
+ SHORTLOCK( &glThreadListLock );
+ new->GlobalPrev = NULL; // Protect against bugs
+ new->GlobalNext = gAllThreads;
+ gAllThreads = new;
+ SHORTREL( &glThreadListLock );
+
return new;
}
/**
- * \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 void 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) {
-
+ Log_Error("Threads", "TODO: Threads_WaitTID(TID=-1) - Any Child");
return -1;
}
// Any peer/child thread
if(TID == 0) {
-
+ Log_Error("Threads", "TODO: Threads_WaitTID(TID=0) - Any Child/Sibling");
return -1;
}
// TGID = abs(TID)
if(TID < -1) {
+ Log_Error("Threads", "TODO: Threads_WaitTID(TID<0) - TGID");
return -1;
}
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) {
- while(t->Status == initStatus) {
- Threads_Yield();
+ // TODO: Handle child also being suspended if wanted
+ while(t->Status != THREAD_STAT_ZOMBIE) {
+ Threads_Sleep();
+ Log_Debug("Threads", "%i waiting for %i, t->Status = %i",
+ Threads_GetTID(), t->TID, t->Status);
}
}
- ret = t->RetStatus;
+ // Set return status
+ Log_Debug("Threads", "%i waiting for %i, t->Status = %i",
+ Threads_GetTID(), t->TID, t->Status);
+ ret = t->TID;
switch(t->Status)
{
case THREAD_STAT_ZOMBIE:
+ // Kill the thread
t->Status = THREAD_STAT_DEAD;
- if(status) *status = 0;
+ // TODO: Child return value?
+ 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;
}
/**
- * \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)
{
tThread *thread;
- // Search Active List
- for(thread = gActiveThreads;
+ // Search global list
+ for(thread = gAllThreads;
thread;
- thread = thread->Next)
- {
- if(thread->TID == TID)
- return thread;
- }
-
- // Search Sleeping List
- for(thread = gSleepingThreads;
- thread;
- thread = thread->Next)
+ thread = thread->GlobalNext)
{
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;
}
/**
- * \fn tThread *Threads_int_GetPrev(tThread **List, tThread *Thread)
- * \brief Gets the previous entry in a thead linked list
+ * \brief Deletes an entry from a list
+ * \param List Pointer to the list head
+ * \param Thread Thread to find
+ * \return \a Thread
*/
-tThread *Threads_int_GetPrev(tThread **List, tThread *Thread)
+tThread *Threads_int_DelFromQueue(tThread **List, tThread *Thread)
{
- tThread *ret;
- // First Entry
- if(*List == Thread) {
- return (tThread*)List;
- } else {
- for(ret = *List;
- ret->Next && ret->Next != Thread;
- ret = ret->Next
- );
- // Error if the thread is not on the list
- if(!ret->Next || ret->Next != Thread) {
- return NULL;
- }
+ tThread *ret, *prev = NULL;
+
+ for(ret = *List;
+ ret && ret != Thread;
+ prev = ret, ret = ret->Next
+ );
+
+ // Is the thread on the list
+ if(!ret) {
+ //LogF("%p(%s) is not on list %p\n", Thread, Thread->ThreadName, List);
+ return NULL;
}
- return ret;
+
+ if( !prev ) {
+ *List = Thread->Next;
+ //LogF("%p(%s) removed from head of %p\n", Thread, Thread->ThreadName, List);
+ }
+ else {
+ prev->Next = Thread->Next;
+ //LogF("%p(%s) removed from %p (prev=%p)\n", Thread, Thread->ThreadName, List, prev);
+ }
+
+ return 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)
{
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();
}
/**
*/
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)
///\note Double lock is needed due to overlap of lock areas
// Lock thread (stop us recieving messages)
- LOCK( &Thread->IsLocked );
-
- // Lock thread list
- LOCK( &glThreadListLock );
-
- // Get previous thread on list
- prev = Threads_int_GetPrev( &gActiveThreads, Thread );
- if(!prev) {
- Warning("Proc_Exit - Current thread is not on the active queue");
- return;
- }
+ SHORTLOCK( &Thread->IsLocked );
// Clear Message Queue
while( Thread->Messages )
Thread->Messages = msg;
}
+ // Lock thread list
+ SHORTLOCK( &glThreadListLock );
+
+ // Delete from active list
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ if( !Threads_int_DelFromQueue( &gaActiveThreads[Thread->Priority], Thread ) )
+ #else
+ if( !Threads_int_DelFromQueue( &gActiveThreads, Thread ) )
+ #endif
+ {
+ Warning("Proc_Exit - Current thread is not on the active queue");
+ SHORTREL( &glThreadListLock );
+ SHORTREL( &Thread->IsLocked );
+ return;
+ }
+
+ // 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 SCHEDULER_TYPE == SCHED_LOTTERY
if( Thread != Proc_GetCurThread() )
- giFreeTickets -= Thread->NumTickets;
- //Log("Threads_Kill: giFreeTickets = %i", giFreeTickets);
+ giFreeTickets -= caiTICKET_COUNTS[ Thread->Priority ];
+ #endif
- // Mark thread as a zombie
+ // 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;
Threads_AddToDelete( Thread );
} else {
Thread->Status = THREAD_STAT_ZOMBIE;
+ // Wake parent
+ Threads_Wake( Thread->Parent );
}
- // Release spinlocks
- RELEASE( &Thread->IsLocked ); // Released first so that it IS released
- RELEASE( &glThreadListLock );
+ Log("Thread %i went *hurk* (%i)", Thread->TID, Thread->Status);
- //Log("Thread %i went *hurk*", Thread->TID);
+ // Release spinlocks
+ 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();
}
/**
void Threads_Sleep(void)
{
tThread *cur = Proc_GetCurThread();
- tThread *thread;
-
- //Log_Log("Threads", "%i going to sleep", cur->TID);
// Acquire Spinlock
- LOCK( &glThreadListLock );
-
- // Get thread before current thread
- thread = Threads_int_GetPrev( &gActiveThreads, cur );
- if(!thread) {
- Warning("Threads_Sleep - Current thread is not on the active queue");
- Threads_Dump();
- RELEASE( &glThreadListLock );
- return;
- }
+ SHORTLOCK( &glThreadListLock );
// Don't sleep if there is a message waiting
if( cur->Messages ) {
- RELEASE( &glThreadListLock );
+ SHORTREL( &glThreadListLock );
return;
}
- // Unset remaining timeslices (force a task switch on timer fire)
- cur->Remaining = 0;
-
- // Remove from active list
- thread->Next = cur->Next;
+ // 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;
- // Reduce the active count & ticket count
- giNumActiveThreads --;
- // 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);
+ #endif
// Release Spinlock
- RELEASE( &glThreadListLock );
+ SHORTREL( &glThreadListLock );
while(cur->Status != THREAD_STAT_ACTIVE) HALT();
}
* \brief Wakes a sleeping/waiting thread up
* \param Thread Thread to wake
* \return Boolean Failure (Returns ERRNO)
+ * \warning This should ONLY be called with task switches disabled
*/
int Threads_Wake(tThread *Thread)
{
- tThread *prev;
-
if(!Thread)
return -EINVAL;
case THREAD_STAT_ACTIVE:
Log("Thread_Wake: Waking awake thread (%i)", Thread->TID);
return -EALREADY;
+
case THREAD_STAT_SLEEPING:
- //Log_Log("Threads", "Waking %i (%p) from sleeping (CPU=%i)",
- // Thread->TID, Thread, Thread->CurCPU);
- LOCK( &glThreadListLock );
- prev = Threads_int_GetPrev(&gSleepingThreads, Thread);
- prev->Next = Thread->Next; // Remove from sleeping queue
- Thread->Next = gActiveThreads; // Add to active queue
- gActiveThreads = Thread;
- giNumActiveThreads ++;
- // Thread can't be the current, so no need to check
- Thread->CurCPU = -1;
- giFreeTickets += Thread->NumTickets;
- #if DEBUG_TRACE_TICKETS
- Log("Threads_Wake: giFreeTickets = %i", giFreeTickets);
+ SHORTLOCK( &glThreadListLock );
+ // Remove from sleeping queue
+ Threads_int_DelFromQueue(&gSleepingThreads, Thread);
+
+ Threads_AddActive( Thread );
+
+ #if DEBUG_TRACE_STATE
+ Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName);
#endif
- Thread->Status = THREAD_STAT_ACTIVE;
- RELEASE( &glThreadListLock );
+ SHORTREL( &glThreadListLock );
return -EOK;
+
case THREAD_STAT_WAITING:
Warning("Thread_Wake - Waiting threads are not currently supported");
return -ENOTIMPL;
+
case THREAD_STAT_DEAD:
Warning("Thread_Wake - Attempt to wake dead thread (%i)", Thread->TID);
return -ENOTIMPL;
+
default:
Warning("Thread_Wake - Unknown process status (%i)\n", Thread->Status);
return -EINTERNAL;
int Threads_WakeTID(tTID TID)
{
tThread *thread = Threads_GetThread(TID);
+ int ret;
if(!thread)
return -ENOENT;
- return Threads_Wake( thread );
+ ret = Threads_Wake( thread );
+ //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)
{
- LOCK( &glThreadListLock );
+ SHORTLOCK( &glThreadListLock );
+
+ // Set state
+ Thread->Status = THREAD_STAT_ACTIVE;
+ Thread->CurCPU = -1;
+ // Add to active list
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ Thread->Next = gaActiveThreads[Thread->Priority];
+ gaActiveThreads[Thread->Priority] = Thread;
+ #else
Thread->Next = gActiveThreads;
gActiveThreads = Thread;
+ #endif
+
+ // Update bookkeeping
giNumActiveThreads ++;
- // Thread can't be the current, so no need to check
- giFreeTickets += Thread->NumTickets;
- #if DEBUG_TRACE_TICKETS
- Log("Threads_AddActive: giFreeTickets = %i", giFreeTickets);
+
+ #if SCHEDULER_TYPE == SCHED_LOTTERY
+ giFreeTickets += caiTICKET_COUNTS[ Thread->Priority ];
+ # if DEBUG_TRACE_TICKETS
+ Log("Threads_AddActive: %p %i (%s) added, new giFreeTickets = %i",
+ Thread, Thread->TID, Thread->ThreadName, giFreeTickets);
+ # endif
#endif
- RELEASE( &glThreadListLock );
+
+ SHORTREL( &glThreadListLock );
+}
+
+/**
+ * \brief Removes the current thread from the active queue
+ * \warning This should ONLY be called with task switches disabled
+ * \return Current thread pointer
+ */
+tThread *Threads_RemActive(void)
+{
+ tThread *ret = Proc_GetCurThread();
+
+ SHORTLOCK( &glThreadListLock );
+
+ // Delete from active queue
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ if( !Threads_int_DelFromQueue(&gaActiveThreads[ret->Priority], ret) )
+ #else
+ if( !Threads_int_DelFromQueue(&gActiveThreads, ret) )
+ #endif
+ {
+ SHORTREL( &glThreadListLock );
+ return NULL;
+ }
+
+ ret->Remaining = 0;
+ ret->CurCPU = -1;
+
+ giNumActiveThreads --;
+ // no need to decrement tickets, scheduler did it for us
+
+ #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
+ Log("Threads_RemActive: %p %i (%s) removed, giFreeTickets = %i",
+ ret, ret->TID, ret->ThreadName, giFreeTickets);
+ #endif
+
+ SHORTREL( &glThreadListLock );
+
+ return ret;
}
/**
*/
void Threads_SetFaultHandler(Uint Handler)
{
- Log_Log("Threads", "Threads_SetFaultHandler: Handler = %p", Handler);
+ //Log_Debug("Threads", "Threads_SetFaultHandler: Handler = %p", Handler);
Proc_GetCurThread()->FaultHandler = Handler;
}
*Errno = -EACCES;
return -1;
}
- Log("Threads_SetUID - Setting User ID to %i", ID);
+ Log_Debug("Threads", "TID %i's UID set to %i", t->TID, ID);
t->UID = ID;
return 0;
}
*Errno = -EACCES;
return -1;
}
- Log("Threads_SetGID - Setting Group ID to %i", ID);
+ Log_Debug("Threads", "TID %i's GID set to %i", t->TID, ID);
t->GID = ID;
return 0;
}
/**
* \fn void Threads_Dump(void)
- * \brief Dums a list of currently running threads
+ */
+void Threads_DumpActive(void)
+{
+ tThread *thread;
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ int i;
+ #endif
+
+ Log("Active Threads: (%i reported)", giNumActiveThreads);
+
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ for( i = 0; i < MIN_PRIORITY+1; i++ )
+ {
+ for(thread=gaActiveThreads[i];thread;thread=thread->Next)
+ #else
+ for(thread=gActiveThreads;thread;thread=thread->Next)
+ #endif
+ {
+ 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(" Priority %i, Quantum %i", thread->Priority, thread->Quantum);
+ Log(" KStack 0x%x", thread->KernelStack);
+ }
+
+ #if SCHEDULER_TYPE == SCHED_RR_PRI
+ }
+ #endif
+}
+
+/**
+ * \fn void Threads_Dump(void)
+ * \brief Dumps a list of currently running threads
*/
void Threads_Dump(void)
{
tThread *thread;
- Log("Active Threads:");
- for(thread=gActiveThreads;thread;thread=thread->Next)
+ Log("--- Thread Dump ---");
+ Threads_DumpActive();
+
+ Log("All Threads:");
+ for(thread=gAllThreads;thread;thread=thread->GlobalNext)
{
Log(" %i (%i) - %s (CPU %i)",
thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
- Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum);
- Log(" KStack 0x%x", thread->KernelStack);
- }
- Log("Sleeping Threads:");
- for(thread=gSleepingThreads;thread;thread=thread->Next)
- {
- Log(" %i (%i) - %s",
- thread->TID, thread->TGID, thread->ThreadName);
- Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum);
+ Log(" State %i", thread->Status);
+ Log(" Priority %i, Quantum %i", thread->Priority, 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
tThread *Threads_GetNextToRun(int CPU, tThread *Last)
{
tThread *thread;
- int ticket;
- int number;
- // TODO: Enable the code to tell if the current CPU has the lock or
- // another does.
+ // If this CPU has the lock, we must let it complete
+ if( CPU_HAS_LOCK( &glThreadListLock ) )
+ return Last;
- // Check if the thread list is locked by other code
- // - If so, don't switch (give it a chance to complete)
- if( IS_LOCKED(&glThreadListLock) )
+ // Don't change threads if the current CPU has switches disabled
+ if( gaThreads_NoTaskSwitch[CPU] )
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;
- if(gDeleteThreads->IsLocked) { // Only free if structure is unused
- gDeleteThreads->Status = THREAD_STAT_NULL;
+ if( IS_LOCKED(&gDeleteThreads->IsLocked) ) { // Only free if structure is unused
+ // Set to dead
+ gDeleteThreads->Status = THREAD_STAT_DEAD;
+ // Free name
+ if( IsHeap(gDeleteThreads->ThreadName) )
+ free(gDeleteThreads->ThreadName);
+ // Remove from global list
+ if( gDeleteThreads == gAllThreads )
+ gAllThreads = gDeleteThreads->GlobalNext;
+ else
+ gDeleteThreads->GlobalPrev->GlobalNext = gDeleteThreads->GlobalNext;
free( gDeleteThreads );
}
gDeleteThreads = thread;
// No active threads, just take a nap
if(giNumActiveThreads == 0) {
+ SHORTREL( &glThreadListLock );
#if DEBUG_TRACE_TICKETS
Log("No active threads");
#endif
return NULL;
}
- // Lock thread list
- // - HLT lock (Used because only another CPU can obtain the lock,
- // but it has a potentially long lock period)
- // - Well, this CPU can obtain the lock, but that is aliveviated by
- // the above.
- TIGHTLOCK( &glThreadListLock );
-
+ #if SCHEDULER_TYPE != SCHED_RR_PRI
// Special case: 1 thread
if(giNumActiveThreads == 1) {
if( gActiveThreads->CurCPU == -1 )
gActiveThreads->CurCPU = CPU;
- RELEASE( &glThreadListLock );
+
+ SHORTREL( &glThreadListLock );
+
if( gActiveThreads->CurCPU == CPU )
return gActiveThreads;
+
return NULL; // CPU has nothing to do
}
+ #endif
// Allow the old thread to be scheduled again
if( Last ) {
if( Last->Status == THREAD_STAT_ACTIVE ) {
- giFreeTickets += Last->NumTickets;
- #if DEBUG_TRACE_TICKETS
- LogF(" CPU %i released %p (%s) into the pool (%i tickets in pool)\n",
- CPU, Last, Last->ThreadName, Last->NumTickets);
+ #if SCHEDULER_TYPE == SCHED_LOTTERY
+ giFreeTickets += caiTICKET_COUNTS[ Last->Priority ];
+ # if DEBUG_TRACE_TICKETS
+ LogF(" CPU %i released %p (%i %s) into the pool (%i tickets in pool)\n",
+ CPU, Last, Last->TID, Last->ThreadName, giFreeTickets);
+ # endif
#endif
}
- #if DEBUG_TRACE_TICKETS
+ #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
else
- LogF(" %p (%s)->Status = %i\n", Last, Last->ThreadName, Last->Status);
+ LogF(" CPU %i released %p (%i %s)->Status = %i (Released)\n",
+ CPU, Last, Last->TID, Last->ThreadName, Last->Status);
#endif
Last->CurCPU = -1;
}
- #if 1
- number = 0;
- for(thread=gActiveThreads;thread;thread=thread->Next) {
- if(thread->CurCPU >= 0) continue;
- number += thread->NumTickets;
- }
- if(number != giFreeTickets) {
- Panic("Bookkeeping fail (giFreeTickets(%i) != number(%i)) - CPU%i",
- giFreeTickets, number, CPU);
- }
- #endif
-
- // No free tickets (all tasks delegated to cores)
- if( giFreeTickets == 0 ) {
- RELEASE(&glThreadListLock);
- return NULL;
+ // ---
+ // Lottery Scheduler
+ // ---
+ #if SCHEDULER_TYPE == SCHED_LOTTERY
+ {
+ int ticket, number;
+ # if 1
+ number = 0;
+ 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 += caiTICKET_COUNTS[ thread->Priority ];
+ }
+ if(number != giFreeTickets) {
+ Panic("Bookkeeping fail (giFreeTickets(%i) != number(%i)) - CPU%i",
+ giFreeTickets, number, CPU);
+ }
+ # endif
+
+ // No free tickets (all tasks delegated to cores)
+ if( giFreeTickets == 0 ) {
+ SHORTREL(&glThreadListLock);
+ return NULL;
+ }
+
+ // Get the ticket number
+ ticket = number = rand() % giFreeTickets;
+
+ // Find the next thread
+ for(thread=gActiveThreads;thread;thread=thread->Next)
+ {
+ if(thread->CurCPU >= 0) continue;
+ if( caiTICKET_COUNTS[ thread->Priority ] > number) break;
+ number -= caiTICKET_COUNTS[ thread->Priority ];
+ }
+
+ // If we didn't find a thread, something went wrong
+ if(thread == NULL)
+ {
+ number = 0;
+ for(thread=gActiveThreads;thread;thread=thread->Next) {
+ if(thread->CurCPU >= 0) continue;
+ number += caiTICKET_COUNTS[ thread->Priority ];
+ }
+ Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)",
+ giFreeTickets, number);
+ }
+ # if DEBUG_TRACE_TICKETS
+ LogF(" CPU%i giFreeTickets = %i, running %p (%i %s CPU=%i)\n",
+ CPU, giFreeTickets, thread, thread->TID, thread->ThreadName, thread->CurCPU);
+ # endif
+
+ giFreeTickets -= caiTICKET_COUNTS[ thread->Priority ];
}
- // Get the ticket number
- ticket = number = rand() % giFreeTickets;
-
- // Find the next thread
- for(thread=gActiveThreads;thread;thread=thread->Next)
+ // ---
+ // Priority based round robin scheduler
+ // ---
+ #elif SCHEDULER_TYPE == SCHED_RR_PRI
{
- if(thread->CurCPU >= 0) continue;
- if(thread->NumTickets > number) break;
- number -= thread->NumTickets;
+ int i;
+ for( i = 0; i < MIN_PRIORITY + 1; i ++ )
+ {
+ for(thread = gaActiveThreads[i]; thread; thread = thread->Next)
+ {
+ if( thread->CurCPU == -1 ) break;
+ }
+ // If we fall onto the same queue again, special handling is
+ // needed
+ if( i == Last->Priority ) {
+ tThread *savedThread = thread;
+
+ // Find the next unscheduled thread in the list
+ for( thread = Last->Next; thread; thread = thread->Next )
+ {
+ if( thread->CurCPU == -1 ) break;
+ }
+ // If we don't find anything after, just use the one
+ // found above.
+ if( !thread ) thread = savedThread;
+ }
+ // Found a thread? Schedule it!
+ if( thread ) break;
+ }
+
+ // Anything to do?
+ if( !thread ) {
+ SHORTREL(&glThreadListLock);
+ return NULL;
+ }
}
- // Error Check
- if(thread == NULL)
- {
- number = 0;
- for(thread=gActiveThreads;thread;thread=thread->Next) {
- if(thread->CurCPU >= 0) continue;
- number += thread->NumTickets;
+ #elif SCHEDULER_TYPE == SCHED_RR_SIM
+ {
+ // Find the next unscheduled thread in the list
+ for( thread = Last->Next; thread; thread = thread->Next )
+ {
+ if( thread->CurCPU == -1 ) break;
+ }
+ // If we don't find anything after, search from the beginning
+ if( !thread )
+ {
+ for(thread = gActiveThreads; thread; thread = thread->Next)
+ {
+ if( thread->CurCPU == -1 ) break;
+ }
+ }
+
+ // Anything to do?
+ if( !thread ) {
+ SHORTREL(&glThreadListLock);
+ return NULL;
}
- Panic("Bookeeping Failed - giFreeTickets(%i) > true count (%i)",
- giFreeTickets, number);
}
- #if DEBUG_TRACE_TICKETS
- LogF(" CPU%i giFreeTickets = %i\n", CPU, giFreeTickets);
+ #else
+ # error "Unimplemented scheduling algorithm"
#endif
// Make the new thread non-schedulable
- giFreeTickets -= thread->NumTickets;
thread->CurCPU = CPU;
- //Threads_Dump();
- #if DEBUG_TRACE_TICKETS
- LogF(" CPU%i giFreeTickets = %i, giving %p (%s CPU=%i)\n",
- CPU, giFreeTickets, thread, thread->ThreadName, thread->CurCPU);
- #endif
-
- RELEASE( &glThreadListLock );
+ SHORTREL( &glThreadListLock );
return thread;
}
//Threads_Exit( 0, -1 );
}
+/**
+ * \brief Acquire a heavy mutex
+ * \param Mutex Mutex to acquire
+ *
+ * This type of mutex checks if the mutex is avaliable, and acquires it
+ * if it is. Otherwise, the current thread is added to the mutex's wait
+ * queue and the thread suspends. When the holder of the mutex completes,
+ * the oldest thread (top thread) on the queue is given the lock and
+ * restarted.
+ */
+void Mutex_Acquire(tMutex *Mutex)
+{
+ tThread *us = Proc_GetCurThread();
+
+ // Get protector
+ SHORTLOCK( &Mutex->Protector );
+
+ //Log("Mutex_Acquire: (%p)", Mutex);
+
+ // Check if the lock is already held
+ if( Mutex->Owner ) {
+ SHORTLOCK( &glThreadListLock );
+ // - Remove from active list
+ us = Threads_RemActive();
+ // - Mark as sleeping
+ us->Status = THREAD_STAT_OFFSLEEP;
+
+ // - Add to waiting
+ if(Mutex->LastWaiting) {
+ Mutex->LastWaiting->Next = us;
+ Mutex->LastWaiting = us;
+ }
+ else {
+ Mutex->Waiting = us;
+ Mutex->LastWaiting = us;
+ }
+ SHORTREL( &glThreadListLock );
+ SHORTREL( &Mutex->Protector );
+ while(us->Status == THREAD_STAT_OFFSLEEP) Threads_Yield();
+ // We're only woken when we get the lock
+ }
+ // Ooh, let's take it!
+ else {
+ Mutex->Owner = us;
+ SHORTREL( &Mutex->Protector );
+ }
+}
+
+/**
+ * \brief Release a held mutex
+ * \param Mutex Mutex to release
+ */
+void Mutex_Release(tMutex *Mutex)
+{
+ SHORTLOCK( &Mutex->Protector );
+ //Log("Mutex_Release: (%p)", Mutex);
+ if( Mutex->Waiting ) {
+ Mutex->Owner = Mutex->Waiting; // Set owner
+ Mutex->Waiting = Mutex->Waiting->Next; // Next!
+ // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
+ // 2010-10-02 21:50 - Comemerating the death of the longest single
+ // blocker in the Acess2 history. REMEMBER TO
+ // FUCKING MAINTAIN YOUR FUCKING LISTS DIPWIT
+ if( Mutex->LastWaiting == Mutex->Owner )
+ Mutex->LastWaiting = NULL;
+
+ // Wake new owner
+ SHORTLOCK( &glThreadListLock );
+ if( Mutex->Owner->Status != THREAD_STAT_ACTIVE )
+ Threads_AddActive(Mutex->Owner);
+ SHORTREL( &glThreadListLock );
+ }
+ else {
+ Mutex->Owner = NULL;
+ }
+ SHORTREL( &Mutex->Protector );
+}
+
+/**
+ * \brief Is this mutex locked?
+ * \param Mutex Mutex pointer
+ */
+int Mutex_IsLocked(tMutex *Mutex)
+{
+ return Mutex->Owner != NULL;
+}
+
// === EXPORTS ===
EXPORT(Threads_GetUID);
+EXPORT(Threads_GetGID);
+EXPORT(Mutex_Acquire);
+EXPORT(Mutex_Release);
+EXPORT(Mutex_IsLocked);
git.ucc.asn.au / tpg / acess2.git / blobdiff
UCC git Repository :: git.ucc.asn.au