#include <threads.h>
#include <errno.h>
+#define DEBUG_TRACE_TICKETS 0
+
// === CONSTANTS ===
#define DEFAULT_QUANTUM 10
#define DEFAULT_TICKETS 5
#define MAX_TICKETS 10
const enum eConfigTypes cCONFIG_TYPES[] = {
- CFGT_HEAPSTR, // CFG_VFS_CWD
- CFGT_INT, // CFG_VFS_MAXFILES
+ CFGT_HEAPSTR, // e.g. CFG_VFS_CWD
+ CFGT_INT, // e.g. CFG_VFS_MAXFILES
CFGT_NULL
};
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);
// === GLOBALS ===
// -- Core Thread --
+// Only used for the core kernel
tThread gThreadZero = {
- NULL, 0, // Next, Lock
- THREAD_STAT_ACTIVE, // Status
- 0, // Exit Status
- 0, 0, // TID, TGID
- 0, 0, // UID, GID
- 0, // Parent Thread ID
- "ThreadZero", // Name
-
- 0, // Kernel Stack
- {0}, // Saved State
- {0}, // VM State
-
- 0, 0, // Current Fault, Fault Handler
-
- NULL, NULL, // Messages, Last Message
- DEFAULT_QUANTUM, DEFAULT_QUANTUM, // Quantum, Remaining
- DEFAULT_TICKETS,
- {0} // Default config to zero
+ Status: THREAD_STAT_ACTIVE, // Status
+ ThreadName: "ThreadZero", // Name
+ 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
// --- Current State ---
volatile int giNumActiveThreads = 0;
-volatile int giTotalTickets = 0;
+//volatile int giTotalTickets = 0;
+volatile int giFreeTickets = 0;
volatile Uint giNextTID = 1;
// --- Thread Lists ---
tThread *gActiveThreads = NULL; // Currently Running Threads
// Create Initial Task
gActiveThreads = &gThreadZero;
- giTotalTickets = gThreadZero.NumTickets;
+ //giFreeTickets = gThreadZero.NumTickets;
giNumActiveThreads = 1;
-
- #if 1
- // Create Idle Task
- if(Proc_Clone(0, 0) == 0)
- {
- tThread *cur = Proc_GetCurThread();
- cur->ThreadName = "Idle Thread";
- Threads_SetTickets(0); // Never called randomly
- cur->Quantum = 1; // 1 slice quantum
- for(;;) HALT(); // Just yeilds
- }
- #endif
-
+
Proc_Start();
}
int Threads_SetName(char *NewName)
{
tThread *cur = Proc_GetCurThread();
- if( IsHeap(cur->ThreadName) )
- free( cur->ThreadName );
- cur->ThreadName = malloc(strlen(NewName)+1);
- strcpy(cur->ThreadName, NewName);
+ char *oldname = cur->ThreadName;
+
+ cur->ThreadName = NULL;
+
+ if( IsHeap(oldname) ) free( oldname );
+
+ cur->ThreadName = strdup(NewName);
return 0;
}
if(ID == -1) {
return Proc_GetCurThread()->ThreadName;
}
+ // TODO: Find a thread and get its name
return NULL;
}
/**
- * \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;
- LOCK( &glThreadListLock );
- giTotalTickets -= cur->NumTickets;
- cur->NumTickets = Num;
- giTotalTickets += Num;
- //LOG("giTotalTickets = %i", giTotalTickets);
- RELEASE( &glThreadListLock );
+ if( Thread != Proc_GetCurThread() ) {
+ LOCK( &glThreadListLock );
+ giFreeTickets -= Thread->NumTickets - Num;
+ Thread->NumTickets = Num;
+ RELEASE( &glThreadListLock );
+ }
+ else
+ Thread->NumTickets = Num;
}
/**
}
memcpy(new, cur, sizeof(tThread));
+ new->CurCPU = -1;
new->Next = NULL;
new->IsLocked = 0;
new->Status = THREAD_STAT_ACTIVE;
/**
* \fn tThread *Threads_GetThread(Uint TID)
* \brief Gets a thread given its TID
+ * \param TID Thread ID
*/
tThread *Threads_GetThread(Uint TID)
{
Threads_Kill( Proc_GetCurThread(), (Uint)Status & 0xFF );
else
Threads_Kill( Threads_GetThread(TID), (Uint)Status & 0xFF );
- for(;;) HALT(); // Just in case
+ // Halt forever, just in case
+ for(;;)
+ HALT();
}
/**
}
#endif
- ///\note Double lock is needed due to overlap of locks
+ ///\note Double lock is needed due to overlap of lock areas
// Lock thread (stop us recieving messages)
LOCK( &Thread->IsLocked );
prev->Next = Thread->Next; // Remove from active
giNumActiveThreads --;
- giTotalTickets -= Thread->NumTickets;
+ if( Thread != Proc_GetCurThread() )
+ giFreeTickets -= Thread->NumTickets;
+ //Log("Threads_Kill: giFreeTickets = %i", giFreeTickets);
// Mark thread as a zombie
Thread->RetStatus = Status;
if(!thread) {
Warning("Threads_Sleep - Current thread is not on the active queue");
Threads_Dump();
+ RELEASE( &glThreadListLock );
return;
}
// Reduce the active count & ticket count
giNumActiveThreads --;
- giTotalTickets -= cur->NumTickets;
// Mark thread as sleeping
cur->Status = THREAD_STAT_SLEEPING;
/**
- * \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_ACTIVE:
+ Log("Thread_Wake: Waking awake thread (%i)", Thread->TID);
+ return -EALREADY;
case THREAD_STAT_SLEEPING:
- //Log_Log("Threads", "Waking %i (%p) from sleeping", Thread->TID, Thread);
+ //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 ++;
- giTotalTickets += Thread->NumTickets;
+ // 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;
+ 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;
}
}
-void Threads_WakeTID(tTID Thread)
+/**
+ * \brief Wake a thread given the TID
+ * \param TID Thread ID to wake
+ * \return Boolean Faulure (errno)
+ */
+int Threads_WakeTID(tTID TID)
{
- Threads_Wake( Threads_GetThread(Thread) );
+ tThread *thread = Threads_GetThread(TID);
+ if(!thread)
+ return -ENOENT;
+ return Threads_Wake( thread );
}
/**
Thread->Next = gActiveThreads;
gActiveThreads = Thread;
giNumActiveThreads ++;
- giTotalTickets += Thread->NumTickets;
- //Log("Threads_AddActive: giNumActiveThreads = %i, giTotalTickets = %i",
- // giNumActiveThreads, giTotalTickets);
+ // Thread can't be the current, so no need to check
+ giFreeTickets += Thread->NumTickets;
+ #if DEBUG_TRACE_TICKETS
+ Log("Threads_AddActive: giFreeTickets = %i", giFreeTickets);
+ #endif
RELEASE( &glThreadListLock );
}
void Threads_Dump(void)
{
tThread *thread;
- tThread *cur = Proc_GetCurThread();
Log("Active Threads:");
for(thread=gActiveThreads;thread;thread=thread->Next)
{
- Log("%c%i (%i) - %s",
- (thread==cur?'*':' '),
- thread->TID, thread->TGID, thread->ThreadName);
+ 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("%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);
}
/**
- * \fn tThread *Threads_GetNextToRun(int CPU)
+ * \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 *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.
+
+ // 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(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;
}
+ // 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 );
+
// Special case: 1 thread
if(giNumActiveThreads == 1) {
- return gActiveThreads;
+ if( gActiveThreads->CurCPU == -1 )
+ gActiveThreads->CurCPU = CPU;
+ RELEASE( &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 ) {
+ 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);
+ return NULL;
}
// Get the ticket number
- ticket = number = rand() % giTotalTickets;
+ ticket = number = rand() % giFreeTickets;
// Find the next thread
for(thread=gActiveThreads;thread;thread=thread->Next)
{
+ if(thread->CurCPU >= 0) continue;
if(thread->NumTickets > number) break;
number -= thread->NumTickets;
}
-
// Error Check
if(thread == NULL)
{
number = 0;
- for(thread=gActiveThreads;thread;thread=thread->Next)
+ for(thread=gActiveThreads;thread;thread=thread->Next) {
+ if(thread->CurCPU >= 0) continue;
number += thread->NumTickets;
- Panic("Bookeeping Failed - giTotalTicketCount (%i) != true count (%i)",
- giTotalTickets, number);
+ }
+ 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;
+
+ //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 );
return thread;
}
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