#include <threads.h>
#include <errno.h>
-#define DEBUG_TRACE_TICKETS 0
+#define DEBUG_TRACE_TICKETS 0 // Trace ticket counts
+#define DEBUG_TRACE_STATE 0 // Trace state changes (sleep/wake)
// === CONSTANTS ===
#define DEFAULT_QUANTUM 10
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 Mutex_Acquire(tMutex *Mutex);
+void Mutex_Release(tMutex *Mutex);
+ int Mutex_IsLocked(tMutex *Mutex);
// === GLOBALS ===
// -- Core Thread --
};
// -- 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;
// --- 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
// Create Initial Task
gActiveThreads = &gThreadZero;
+ gAllThreads = &gThreadZero;
//giFreeTickets = gThreadZero.NumTickets;
giNumActiveThreads = 1;
if(Num > MAX_TICKETS) Num = MAX_TICKETS;
if( Thread != Proc_GetCurThread() ) {
- LOCK( &glThreadListLock );
+ SHORTLOCK( &glThreadListLock );
giFreeTickets -= Thread->NumTickets - Num;
Thread->NumTickets = Num;
- RELEASE( &glThreadListLock );
+ 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;
// Get Thread ID
new->TID = giNextTID++;
- new->PTID = cur->TID;
+ new->Parent = cur;
// Clone Name
new->ThreadName = strdup(cur->ThreadName);
}
}
+ // Maintain a global list of threads
+ SHORTLOCK( &glThreadListLock );
+ new->GlobalPrev = NULL; // Protect against bugs
+ new->GlobalNext = gAllThreads;
+ gAllThreads = new;
+ SHORTREL( &glThreadListLock );
+
return new;
}
}
/**
- * \fn void Threads_WaitTID(int TID, int *status)
+ * \fn tTID Threads_WaitTID(int TID, int *status)
* \brief Wait for a task to change state
+ * \return TID of child that changed state
*/
int 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;
}
int ret;
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);
}
}
+ Log_Debug("Threads", "%i waiting for %i, t->Status = %i",
+ Threads_GetTID(), t->TID, t->Status);
ret = t->RetStatus;
switch(t->Status)
{
case THREAD_STAT_ZOMBIE:
+ // Kill the thread
t->Status = THREAD_STAT_DEAD;
+ // TODO: Child return value?
if(status) *status = 0;
+ // add to delete queue
Threads_AddToDelete( t );
break;
default:
{
tThread *thread;
- // Search Active List
- for(thread = gActiveThreads;
- thread;
- thread = thread->Next)
- {
- if(thread->TID == TID)
- return thread;
- }
-
- // Search Sleeping List
- for(thread = gSleepingThreads;
+ // Search global list
+ for(thread = gAllThreads;
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;
}
///\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");
+ SHORTREL( &Thread->IsLocked );
+ SHORTREL( &glThreadListLock );
return;
}
giNumActiveThreads --;
if( Thread != Proc_GetCurThread() )
giFreeTickets -= Thread->NumTickets;
- //Log("Threads_Kill: giFreeTickets = %i", giFreeTickets);
- // Mark thread as a zombie
+ // Save exit status
Thread->RetStatus = Status;
// Don't Zombie if we are being killed as part of a tree
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( &Thread->IsLocked );
+ SHORTREL( &glThreadListLock );
if(Status != -1) 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();
// 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)
+ * \note Should be called with the scheduler lock held
*/
int Threads_Wake(tThread *Thread)
{
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 );
+
+ case THREAD_STAT_SLEEPING: // TODO: Comment better
+ // Remove from sleeping queue
prev = Threads_int_GetPrev(&gSleepingThreads, Thread);
- prev->Next = Thread->Next; // Remove from sleeping queue
- Thread->Next = gActiveThreads; // Add to active queue
+ prev->Next = Thread->Next;
+ // Add to active queue
+ Thread->Next = gActiveThreads;
gActiveThreads = Thread;
+ // Update bookkeeping
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);
+ Log("Threads_Wake: new giFreeTickets = %i", giFreeTickets);
#endif
+ Thread->CurCPU = -1;
Thread->Status = THREAD_STAT_ACTIVE;
- RELEASE( &glThreadListLock );
+ #if DEBUG_TRACE_STATE
+ Log("Threads_Sleep: %p (%i %s) woken", Thread, Thread->TID, Thread->ThreadName);
+ #endif
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 );
+ SHORTLOCK( &glThreadListLock );
+ ret = Threads_Wake( thread );
+ SHORTREL( &glThreadListLock );
+ return ret;
}
/**
*/
void Threads_AddActive(tThread *Thread)
{
- LOCK( &glThreadListLock );
+ SHORTLOCK( &glThreadListLock );
+ // Add to active list
Thread->Next = gActiveThreads;
gActiveThreads = Thread;
+ // 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);
+ Log("Threads_AddActive: new giFreeTickets = %i", giFreeTickets);
#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();
+ tThread *prev = Threads_int_GetPrev(&gActiveThreads, ret);
+ if(!prev) return NULL;
+ ret->Remaining = 0;
+ ret->CurCPU = -1;
+ prev->Next = ret->Next;
+ giNumActiveThreads --;
+ 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;
}
{
Log(" %i (%i) - %s (CPU %i)",
thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
+ Log(" State: %i", thread->Status);
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("All Threads:");
+ for(thread=gAllThreads;thread;thread=thread->GlobalNext)
{
- Log(" %i (%i) - %s",
- thread->TID, thread->TGID, thread->ThreadName);
+ Log(" %i (%i) - %s (CPU %i)",
+ thread->TID, thread->TGID, thread->ThreadName, thread->CurCPU);
+ Log(" State: %i", thread->Status);
Log(" %i Tickets, Quantum %i", thread->NumTickets, thread->Quantum);
Log(" KStack 0x%x", thread->KernelStack);
}
{
tThread *thread;
int ticket;
- int number;
+ 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;
+ // Lock thread list
+ SHORTLOCK( &glThreadListLock );
// Clear Delete Queue
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 );
-
// 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
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);
+ LogF(" CPU %i released %p (%i %s) into the pool (%i tickets in pool)\n",
+ CPU, Last, Last->TID, Last->ThreadName, giFreeTickets);
#endif
}
#if DEBUG_TRACE_TICKETS
// No free tickets (all tasks delegated to cores)
if( giFreeTickets == 0 ) {
- RELEASE(&glThreadListLock);
+ SHORTREL(&glThreadListLock);
return NULL;
}
//Threads_Dump();
#if DEBUG_TRACE_TICKETS
- LogF(" CPU%i giFreeTickets = %i, giving %p (%s CPU=%i)\n",
- CPU, giFreeTickets, thread, thread->ThreadName, thread->CurCPU);
+ LogF(" CPU%i giFreeTickets = %i, giving %p (%i %s CPU=%i)\n",
+ CPU, giFreeTickets, thread, thread->TID, 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
+ 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) 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);
+EXPORT(Mutex_Acquire);
+EXPORT(Mutex_Release);
+EXPORT(Mutex_IsLocked);
git.ucc.asn.au / tpg / acess2.git / blobdiff
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