#include <threads.h>
#include <errno.h>
+#define DEBUG_TRACE_TICKETS 0
+
// === CONSTANTS ===
#define DEFAULT_QUANTUM 10
#define DEFAULT_TICKETS 5
void Threads_Init(void);
int Threads_SetName(char *NewName);
char *Threads_GetName(int ID);
-void Threads_SetTickets(int Num);
+void Threads_SetTickets(tThread *Thread, int Num);
tThread *Threads_CloneTCB(Uint *Err, Uint Flags);
int Threads_WaitTID(int TID, int *status);
tThread *Threads_GetThread(Uint TID);
void Threads_Kill(tThread *Thread, int Status);
void Threads_Yield(void);
void Threads_Sleep(void);
-void Threads_Wake(tThread *Thread);
+ int Threads_Wake(tThread *Thread);
void Threads_AddActive(tThread *Thread);
int Threads_GetPID(void);
int Threads_GetTID(void);
tGID Threads_GetGID(void);
int Threads_SetGID(Uint *Errno, tUID ID);
void Threads_Dump(void);
+void Mutex_Acquire(tMutex *Mutex);
+void Mutex_Release(tMutex *Mutex);
+ int Mutex_IsLocked(tMutex *Mutex);
// === GLOBALS ===
// -- Core Thread --
tThread gThreadZero = {
Status: THREAD_STAT_ACTIVE, // Status
ThreadName: "ThreadZero", // Name
- Quantum: DEFAULT_QUANTUM, Remaining: DEFAULT_QUANTUM, // Quantum, Remaining
- NumTickets: DEFAULT_TICKETS
+ Quantum: DEFAULT_QUANTUM, // Default Quantum
+ Remaining: DEFAULT_QUANTUM, // Current Quantum
+ NumTickets: DEFAULT_TICKETS // 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;
}
/**
- * \fn void Threads_SetTickets(int Num)
+ * \fn void Threads_SetTickets(tThread *Thread, int Num)
* \brief Sets the 'priority' of a task
*/
-void Threads_SetTickets(int Num)
+void Threads_SetTickets(tThread *Thread, int Num)
{
- tThread *cur = Proc_GetCurThread();
+ if(Thread == NULL)
+ Thread = Proc_GetCurThread();
if(Num < 0) return;
if(Num > MAX_TICKETS) Num = MAX_TICKETS;
- cur->NumTickets = Num;
+ if( Thread != Proc_GetCurThread() ) {
+ SHORTLOCK( &glThreadListLock );
+ giFreeTickets -= Thread->NumTickets - Num;
+ Thread->NumTickets = Num;
+ SHORTREL( &glThreadListLock );
+ }
+ else
+ Thread->NumTickets = Num;
}
/**
new->CurCPU = -1;
new->Next = NULL;
- new->IsLocked = 0;
+ memset( &new->IsLocked, 0, sizeof(new->IsLocked));
new->Status = THREAD_STAT_ACTIVE;
new->RetStatus = 0;
new->PTID = cur->TID;
// Clone Name
- Log("Threads_CloneTCB: cur (%p) ->ThreadName = %p", cur, cur->ThreadName);
new->ThreadName = strdup(cur->ThreadName);
// Set Thread Group ID (PID)
///\note Double lock is needed due to overlap of lock areas
// Lock thread (stop us recieving messages)
- LOCK( &Thread->IsLocked );
+ SHORTLOCK( &Thread->IsLocked );
// Lock thread list
- LOCK( &glThreadListLock );
+ SHORTLOCK( &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");
+ Thread->IsLocked.Lock = 0; // We can't use SHORTREL as that starts IRQs again
+ SHORTREL( &glThreadListLock );
return;
}
giNumActiveThreads --;
if( Thread != Proc_GetCurThread() )
giFreeTickets -= Thread->NumTickets;
+ //Log("Threads_Kill: giFreeTickets = %i", giFreeTickets);
// Mark thread as a zombie
Thread->RetStatus = Status;
}
// Release spinlocks
- RELEASE( &Thread->IsLocked ); // Released first so that it IS released
- RELEASE( &glThreadListLock );
+ Thread->IsLocked.Lock = 0; // Released first so that it IS released
+ SHORTREL( &glThreadListLock );
//Log("Thread %i went *hurk*", Thread->TID);
//Log_Log("Threads", "%i going to sleep", cur->TID);
// Acquire Spinlock
- LOCK( &glThreadListLock );
+ SHORTLOCK( &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 );
+ SHORTREL( &glThreadListLock );
return;
}
// Don't sleep if there is a message waiting
if( cur->Messages ) {
- RELEASE( &glThreadListLock );
+ SHORTREL( &glThreadListLock );
return;
}
// Reduce the active count & ticket count
giNumActiveThreads --;
- //giTotalTickets -= cur->NumTickets;
+ // - No need to alter giFreeTickets (we're being executed)
// Mark thread as sleeping
cur->Status = THREAD_STAT_SLEEPING;
// Release Spinlock
- RELEASE( &glThreadListLock );
+ SHORTREL( &glThreadListLock );
while(cur->Status != THREAD_STAT_ACTIVE) HALT();
}
/**
- * \fn void Threads_Wake( tThread *Thread )
+ * \fn int Threads_Wake( tThread *Thread )
* \brief Wakes a sleeping/waiting thread up
+ * \param Thread Thread to wake
+ * \return Boolean Failure (Returns ERRNO)
*/
-void Threads_Wake(tThread *Thread)
+int Threads_Wake(tThread *Thread)
{
tThread *prev;
+
+ if(!Thread)
+ return -EINVAL;
+
switch(Thread->Status)
{
- case THREAD_STAT_ACTIVE: break;
- case THREAD_STAT_SLEEPING:
- //Log_Log("Threads", "Waking %i (%p) from sleeping", Thread->TID, Thread);
- LOCK( &glThreadListLock );
+ case THREAD_STAT_ACTIVE:
+ Log("Thread_Wake: Waking awake thread (%i)", Thread->TID);
+ return -EALREADY;
+ case THREAD_STAT_SLEEPING: // TODO: Comment better
+ //Log_Log("Threads", "Waking %i (%p) from sleeping (CPU=%i)",
+ // Thread->TID, Thread, Thread->CurCPU);
+ SHORTLOCK( &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);
+ #endif
Thread->Status = THREAD_STAT_ACTIVE;
- RELEASE( &glThreadListLock );
- break;
+ SHORTREL( &glThreadListLock );
+ return -EOK;
case THREAD_STAT_WAITING:
Warning("Thread_Wake - Waiting threads are not currently supported");
- break;
+ return -ENOTIMPL;
case THREAD_STAT_DEAD:
Warning("Thread_Wake - Attempt to wake dead thread (%i)", Thread->TID);
- break;
+ return -ENOTIMPL;
default:
Warning("Thread_Wake - Unknown process status (%i)\n", Thread->Status);
- break;
+ return -EINTERNAL;
}
}
/**
* \brief Wake a thread given the TID
+ * \param TID Thread ID to wake
+ * \return Boolean Faulure (errno)
*/
-void Threads_WakeTID(tTID Thread)
+int Threads_WakeTID(tTID TID)
{
- Threads_Wake( Threads_GetThread(Thread) );
+ tThread *thread = Threads_GetThread(TID);
+ if(!thread)
+ return -ENOENT;
+ return Threads_Wake( thread );
}
/**
*/
void Threads_AddActive(tThread *Thread)
{
- LOCK( &glThreadListLock );
+ SHORTLOCK( &glThreadListLock );
Thread->Next = gActiveThreads;
gActiveThreads = Thread;
giNumActiveThreads ++;
// Thread can't be the current, so no need to check
giFreeTickets += Thread->NumTickets;
- //Log("Threads_AddActive: giNumActiveThreads = %i, giTotalTickets = %i",
- // giNumActiveThreads, giTotalTickets);
- RELEASE( &glThreadListLock );
+ #if DEBUG_TRACE_TICKETS
+ Log("Threads_AddActive: giFreeTickets = %i", giFreeTickets);
+ #endif
+ SHORTREL( &glThreadListLock );
}
/**
void Threads_Dump(void)
{
tThread *thread;
- tThread *cur = Proc_GetCurThread();
Log("Active Threads:");
for(thread=gActiveThreads;thread;thread=thread->Next)
Log("Sleeping Threads:");
for(thread=gSleepingThreads;thread;thread=thread->Next)
{
- Log("%c%i (%i) - %s",
- (thread==cur?'*':' '),
+ Log(" %i (%i) - %s",
thread->TID, thread->TGID, thread->ThreadName);
Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum);
Log(" KStack 0x%x", thread->KernelStack);
int ticket;
int number;
- // Note: Enable the code to tell if the switch code has the lock, or
- // if it's the other code.
+ // TODO: Enable the code to tell if the current CPU has the lock or
+ // another does.
// 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) )
return Last;
+ // Clear Delete Queue
+ while(gDeleteThreads)
+ {
+ thread = gDeleteThreads->Next;
+ if( IS_LOCKED(&gDeleteThreads->IsLocked) ) { // Only free if structure is unused
+ gDeleteThreads->Status = THREAD_STAT_NULL;
+ free( gDeleteThreads );
+ }
+ gDeleteThreads = thread;
+ }
+
// No active threads, just take a nap
if(giNumActiveThreads == 0) {
+ #if DEBUG_TRACE_TICKETS
+ Log("No active threads");
+ #endif
return NULL;
}
// but it has a potentially long lock period)
// - Well, this CPU can obtain the lock, but that is aliveviated by
// the above.
- TIGHTLOCK( &glThreadListLock );
+ SHORTLOCK( &glThreadListLock );
// 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
// Allow the old thread to be scheduled again
if( Last ) {
- if( Last->Status == THREAD_STAT_ACTIVE )
+ 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);
+ #endif
+ }
+ #if DEBUG_TRACE_TICKETS
+ else
+ LogF(" %p (%s)->Status = %i\n", Last, 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);
+ 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);
+ #endif
// Make the new thread non-schedulable
giFreeTickets -= thread->NumTickets;
thread->CurCPU = CPU;
- RELEASE( &glThreadListLock );
+ //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
+
+ 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();
+ tThread *prev;
+
+ // 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->Remaining = 0;
+ prev = Threads_int_GetPrev(&gActiveThreads, us);
+ prev->Next = us->Next;
+ giNumActiveThreads --;
+ us->Status = THREAD_STAT_SLEEPING;
+
+ // - 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_SLEEPING) HALT();
+ // 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!
+ // Wake new owner
+ Mutex->Owner->Status = THREAD_STAT_ACTIVE;
+ Threads_AddActive(Mutex->Owner);
+ Log("Mutex %p Woke %p", Mutex, Mutex->Owner);
+ }
+ 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);
git.ucc.asn.au / tpg / acess2.git / blobdiff
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