Kernel/armv7 - Fixing bugs, Proc_Clone works now
[tpg/acess2.git] / Kernel / threads.c
index dc79908..78e53ac 100644 (file)
@@ -5,12 +5,16 @@
  */
 #include <acess.h>
 #include <threads.h>
+#include <threads_int.h>
 #include <errno.h>
+#include <mutex.h>
 #include <semaphore.h>
+#include <hal_proc.h>
 
 // Configuration
 #define DEBUG_TRACE_TICKETS    0       // Trace ticket counts
 #define DEBUG_TRACE_STATE      0       // Trace state changes (sleep/wake)
+#define SEMAPHORE_DEBUG        0
 
 // --- Schedulers ---
 #define SCHED_UNDEF    0
 #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
+#define SCHEDULER_TYPE SCHED_RR_PRI
 
 // === CONSTANTS ===
-#define        DEFAULT_QUANTUM 10
+#define        DEFAULT_QUANTUM 5
 #define        DEFAULT_PRIORITY        5
 #define MIN_PRIORITY           10
 const enum eConfigTypes        cCONFIG_TYPES[] = {
@@ -31,9 +35,6 @@ const enum eConfigTypes       cCONFIG_TYPES[] = {
 };
 
 // === IMPORTS ===
-extern void    ArchThreads_Init(void);
-extern void    Proc_CallFaultHandler(tThread *Thread);
-extern int     GetCPUNum(void);
 
 // === PROTOTYPES ===
 void   Threads_Init(void);
@@ -58,6 +59,7 @@ void  Threads_Sleep(void);
 void   Threads_AddActive(tThread *Thread);
 tThread        *Threads_RemActive(void);
 #endif
+void   Threads_ToggleTrace(int TID);
 void   Threads_Fault(int Num);
 void   Threads_SegFault(tVAddr Addr);
 #if 0
@@ -70,7 +72,6 @@ tGID  Threads_GetGID(void);
 #endif
 void   Threads_Dump(void);
 void   Threads_DumpActive(void);
-
 #if 0
  int   Mutex_Acquire(tMutex *Mutex);
 void   Mutex_Release(tMutex *Mutex);
@@ -81,11 +82,11 @@ void        Mutex_Release(tMutex *Mutex);
 // -- Core Thread --
 // Only used for the core kernel
 tThread        gThreadZero = {
-       Status: THREAD_STAT_ACTIVE,     // Status
-       ThreadName:     (char*)"ThreadZero",    // Name
-       Quantum: DEFAULT_QUANTUM,       // Default Quantum
-       Remaining:      DEFAULT_QUANTUM,        // Current Quantum
-       Priority:       DEFAULT_PRIORITY        // Number of tickets
+       .Status         = THREAD_STAT_ACTIVE,   // Status
+       .ThreadName     = (char*)"ThreadZero",  // Name
+       .Quantum        = DEFAULT_QUANTUM,      // Default Quantum
+       .Remaining      = DEFAULT_QUANTUM,      // Current Quantum
+       .Priority       = DEFAULT_PRIORITY      // Number of tickets
        };
 // -- Processes --
 // --- Locks ---
@@ -121,6 +122,10 @@ void Threads_Init(void)
 {
        ArchThreads_Init();
        
+       Log_Debug("Threads", "Offsets of tThread");
+       Log_Debug("Threads", ".Priority = %i", offsetof(tThread, Priority));
+       Log_Debug("Threads", ".KernelStack = %i", offsetof(tThread, KernelStack));
+       
        // Create Initial Task
        #if SCHEDULER_TYPE == SCHED_RR_PRI
        gaActiveThreads[gThreadZero.Priority] = &gThreadZero;
@@ -183,6 +188,7 @@ void Threads_SetPriority(tThread *Thread, int Pri)
        if(Thread == NULL)      Thread = Proc_GetCurThread();
        // Bounds checking
        // - If < 0, set to lowest priority
+       // - Minumum priority is actualy a high number, 0 is highest
        if(Pri < 0)     Pri = MIN_PRIORITY;
        if(Pri > MIN_PRIORITY)  Pri = MIN_PRIORITY;
        
@@ -207,7 +213,9 @@ void Threads_SetPriority(tThread *Thread, int Pri)
                #if SCHEDULER_TYPE == SCHED_LOTTERY
                giFreeTickets -= caiTICKET_COUNTS[Thread->Priority] - caiTICKET_COUNTS[Pri];
                # if DEBUG_TRACE_TICKETS
-               Log("Threads_SetTickets: new giFreeTickets = %i", giFreeTickets);
+               Log("Threads_SetTickets: new giFreeTickets = %i [-%i+%i]",
+                       giFreeTickets,
+                       caiTICKET_COUNTS[Thread->Priority], caiTICKET_COUNTS[Pri]);
                # endif
                #endif
                Thread->Priority = Pri;
@@ -216,15 +224,19 @@ void Threads_SetPriority(tThread *Thread, int Pri)
        else
                Thread->Priority = Pri;
        #endif
+       
+       #if DEBUG_TRACE_STATE
+       Log("Threads_SetPriority: %p(%i %s) pri set %i",
+               Thread, Thread->TID, Thread->ThreadName,
+               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)
+tThread *Threads_CloneTCB(Uint Flags)
 {
        tThread *cur, *new;
         int    i;
@@ -232,10 +244,7 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags)
        
        // Allocate and duplicate
        new = malloc(sizeof(tThread));
-       if(new == NULL) {
-               *Err = -ENOMEM;
-               return NULL;
-       }
+       if(new == NULL) { errno = -ENOMEM; return NULL; }
        memcpy(new, cur, sizeof(tThread));
        
        new->CurCPU = -1;
@@ -247,6 +256,7 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags)
        // Get Thread ID
        new->TID = giNextTID++;
        new->Parent = cur;
+       new->bInstrTrace = 0;
        
        // Clone Name
        new->ThreadName = strdup(cur->ThreadName);
@@ -297,14 +307,12 @@ tThread *Threads_CloneTCB(Uint *Err, Uint Flags)
 }
 
 /**
- * \fn tThread *Threads_CloneTCB(Uint *Err, Uint Flags)
- * \brief Clone the TCB of the current thread
+ * \brief Clone the TCB of the kernel thread
  */
 tThread *Threads_CloneThreadZero(void)
 {
-       tThread *cur, *new;
+       tThread *new;
         int    i;
-       cur = Proc_GetCurThread();
        
        // Allocate and duplicate
        new = malloc(sizeof(tThread));
@@ -331,27 +339,17 @@ tThread *Threads_CloneThreadZero(void)
        new->LastMessage = NULL;
        
        // Set State
-       new->Remaining = new->Quantum = cur->Quantum;
-       new->Priority = cur->Priority;
+       new->Remaining = new->Quantum = DEFAULT_QUANTUM;
+       new->Priority = DEFAULT_PRIORITY;
+       new->bInstrTrace = 0;
        
        // Set Signal Handlers
        new->CurFaultNum = 0;
-       new->FaultHandler = cur->FaultHandler;
+       new->FaultHandler = 0;
        
        for( i = 0; i < NUM_CFG_ENTRIES; i ++ )
        {
-               switch(cCONFIG_TYPES[i])
-               {
-               default:
-                       new->Config[i] = cur->Config[i];
-                       break;
-               case CFGT_HEAPSTR:
-                       if(cur->Config[i])
-                               new->Config[i] = (Uint) strdup( (void*)cur->Config[i] );
-                       else
-                               new->Config[i] = 0;
-                       break;
-               }
+               new->Config[i] = 0;
        }
        
        // Maintain a global list of threads
@@ -655,9 +653,10 @@ void Threads_Kill(tThread *Thread, int Status)
        SHORTREL( &Thread->IsLocked );  // TODO: We may not actually be released...
        
        // And, reschedule
-       if(isCurThread) {
+       if(isCurThread)
+       {
                for( ;; )
-                       HALT();
+                       Proc_Reschedule();
        }
 }
 
@@ -666,10 +665,8 @@ void Threads_Kill(tThread *Thread, int Status)
  */
 void Threads_Yield(void)
 {
-       tThread *thread = Proc_GetCurThread();
-       thread->Remaining = 0;
-       //while(thread->Remaining == 0)
-               HALT();
+//     Log("Threads_Yield: by %p", __builtin_return_address(0));
+       Proc_Reschedule();
 }
 
 /**
@@ -705,8 +702,12 @@ void Threads_Sleep(void)
        
        // Release Spinlock
        SHORTREL( &glThreadListLock );
-       
-       while(cur->Status != THREAD_STAT_ACTIVE)        HALT();
+
+       while(cur->Status != THREAD_STAT_ACTIVE) {
+               Proc_Reschedule();
+               if( cur->Status != THREAD_STAT_ACTIVE )
+                       Log("%i - Huh? why am I up? zzzz...", cur->TID);
+       }
 }
 
 
@@ -725,7 +726,7 @@ int Threads_Wake(tThread *Thread)
        switch(Thread->Status)
        {
        case THREAD_STAT_ACTIVE:
-               Log("Thread_Wake: Waking awake thread (%i)", Thread->TID);
+               Log("Threads_Wake - Waking awake thread (%i)", Thread->TID);
                return -EALREADY;
        
        case THREAD_STAT_SLEEPING:
@@ -741,16 +742,66 @@ int Threads_Wake(tThread *Thread)
                SHORTREL( &glThreadListLock );
                return -EOK;
        
+       case THREAD_STAT_SEMAPHORESLEEP: {
+               tSemaphore      *sem;
+               tThread *th, *prev=NULL;
+               
+               sem = Thread->WaitPointer;
+               
+               SHORTLOCK( &sem->Protector );
+               
+               // Remove from sleeping queue
+               for( th = sem->Waiting; th; prev = th, th = th->Next )
+                       if( th == Thread )      break;
+               if( th )
+               {
+                       if(prev)
+                               prev->Next = Thread->Next;
+                       else
+                               sem->Waiting = Thread->Next;
+                       if(sem->LastWaiting == Thread)
+                               sem->LastWaiting = prev;
+               }
+               else
+               {
+                       prev = NULL;
+                       for( th = sem->Signaling; th; prev = th, th = th->Next )
+                               if( th == Thread )      break;
+                       if( !th ) {
+                               Log_Warning("Threads", "Thread %p(%i %s) is not on semaphore %p(%s:%s)",
+                                       Thread, Thread->TID, Thread->ThreadName,
+                                       sem, sem->ModName, sem->Name);
+                               return -EINTERNAL;
+                       }
+                       
+                       if(prev)
+                               prev->Next = Thread->Next;
+                       else
+                               sem->Signaling = Thread->Next;
+                       if(sem->LastSignaling == Thread)
+                               sem->LastSignaling = prev;
+               }
+               
+               SHORTLOCK( &glThreadListLock );
+               Threads_AddActive( Thread );
+               SHORTREL( &glThreadListLock );
+               
+               #if DEBUG_TRACE_STATE
+               Log("Threads_Sleep: %p(%i %s) woken from semaphore", Thread, Thread->TID, Thread->ThreadName);
+               #endif
+               SHORTREL( &sem->Protector );
+               } return -EOK;
+       
        case THREAD_STAT_WAITING:
-               Warning("Thread_Wake - Waiting threads are not currently supported");
+               Warning("Threads_Wake - Waiting threads are not currently supported");
                return -ENOTIMPL;
        
        case THREAD_STAT_DEAD:
-               Warning("Thread_Wake - Attempt to wake dead thread (%i)", Thread->TID);
+               Warning("Threads_Wake - Attempt to wake dead thread (%i)", Thread->TID);
                return -ENOTIMPL;
        
        default:
-               Warning("Thread_Wake - Unknown process status (%i)\n", Thread->Status);
+               Warning("Threads_Wake - Unknown process status (%i)\n", Thread->Status);
                return -EINTERNAL;
        }
 }
@@ -771,6 +822,13 @@ int Threads_WakeTID(tTID TID)
        return ret;
 }
 
+void Threads_ToggleTrace(int TID)
+{
+       tThread *thread = Threads_GetThread(TID);
+       if(!thread)     return ;
+       thread->bInstrTrace = !thread->bInstrTrace;
+}
+
 /**
  * \brief Adds a thread to the active queue
  */
@@ -780,31 +838,55 @@ void Threads_AddActive(tThread *Thread)
        
        if( Thread->Status == THREAD_STAT_ACTIVE ) {
                tThread *cur = Proc_GetCurThread();
-               Warning("WTF, CPU%i %p (%i %s) is adding %p (%i %s) when it is active",
+               Log_Warning("Threads", "WTF, %p CPU%i %p (%i %s) is adding %p (%i %s) when it is active",
+                       __builtin_return_address(0),
                        GetCPUNum(), cur, cur->TID, cur->ThreadName, Thread, Thread->TID, Thread->ThreadName);
+               SHORTREL( &glThreadListLock );
+               return ;
        }
        
        // Set state
        Thread->Status = THREAD_STAT_ACTIVE;
-       Thread->CurCPU = -1;
+//     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
+       {
+               tThread *tmp, *prev = NULL;
+               #if SCHEDULER_TYPE == SCHED_RR_PRI
+               for( tmp = gaActiveThreads[Thread->Priority]; tmp; prev = tmp, tmp = tmp->Next );
+               if(prev)
+                       prev->Next = Thread;
+               else
+                       gaActiveThreads[Thread->Priority] = Thread;
+               #else
+               for( tmp = gActiveThreads; tmp; prev = tmp, tmp = tmp->Next );
+               if(prev)
+                       prev->Next = Thread;
+               else
+                       gActiveThreads = Thread;
+               #endif
+               Thread->Next = NULL;
+       }
        
        // Update bookkeeping
        giNumActiveThreads ++;
        
        #if SCHEDULER_TYPE == SCHED_LOTTERY
-       giFreeTickets += caiTICKET_COUNTS[ Thread->Priority ];
-       # if DEBUG_TRACE_TICKETS
-       Log("Threads_AddActive: CPU%i %p %i (%s) added, new giFreeTickets = %i",
-               GetCPUNum(), Thread, Thread->TID, Thread->ThreadName, giFreeTickets);
-       # endif
+       {
+                int    delta;
+               // Only change the ticket count if the thread is un-scheduled
+               if(Thread->CurCPU != -1)
+                       delta = 0;
+               else
+                       delta = caiTICKET_COUNTS[ Thread->Priority ];
+               
+               giFreeTickets += delta;
+               # if DEBUG_TRACE_TICKETS
+               Log("CPU%i %p (%i %s) added, new giFreeTickets = %i [+%i]",
+                       GetCPUNum(), Thread, Thread->TID, Thread->ThreadName,
+                       giFreeTickets, delta
+                       );
+               # endif
+       }
        #endif
        
        SHORTREL( &glThreadListLock );
@@ -812,14 +894,17 @@ void Threads_AddActive(tThread *Thread)
 
 /**
  * \brief Removes the current thread from the active queue
- * \warning This should ONLY be called with task switches disabled
+ * \warning This should ONLY be called with the lock held
  * \return Current thread pointer
  */
 tThread *Threads_RemActive(void)
 {
        tThread *ret = Proc_GetCurThread();
-       
-       SHORTLOCK( &glThreadListLock );
+
+       if( !IS_LOCKED(&glThreadListLock) ) {
+               Log_KernelPanic("Threads", "Threads_RemActive called without lock held");
+               return NULL;
+       }
        
        // Delete from active queue
        #if SCHEDULER_TYPE == SCHED_RR_PRI
@@ -829,23 +914,23 @@ tThread *Threads_RemActive(void)
        #endif
        {
                SHORTREL( &glThreadListLock );
+               Log_Warning("Threads", "Current thread %p(%i %s) is not on active queue",
+                       ret, ret->TID, ret->ThreadName
+                       );
                return NULL;
        }
        
        ret->Next = 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: CPU%i %p %i (%s) removed, giFreeTickets = %i",
+       Log("CPU%i %p (%i %s) removed, giFreeTickets = %i [nc]",
                GetCPUNum(), ret, ret->TID, ret->ThreadName, giFreeTickets);
        #endif
        
-       SHORTREL( &glThreadListLock );
-       
        return ret;
 }
 
@@ -867,8 +952,6 @@ void Threads_Fault(int Num)
 {
        tThread *thread = Proc_GetCurThread();
        
-       Log_Log("Threads", "Threads_Fault: thread = %p", thread);
-       
        if(!thread)     return ;
        
        Log_Log("Threads", "Threads_Fault: thread->FaultHandler = %p", thread->FaultHandler);
@@ -887,6 +970,7 @@ void Threads_Fault(int Num)
        
        // Double Fault? Oh, F**k
        if(thread->CurFaultNum != 0) {
+               Log_Warning("Threads", "Threads_Fault: Double fault on %i", thread->TID);
                Threads_Kill(thread, -1);       // For now, just kill
                HALT();
        }
@@ -902,7 +986,10 @@ void Threads_Fault(int Num)
  */
 void Threads_SegFault(tVAddr Addr)
 {
-       Warning("Thread #%i committed a segfault at address %p", Proc_GetCurThread()->TID, Addr);
+       tThread *cur = Proc_GetCurThread();
+       cur->bInstrTrace = 0;
+       Log_Warning("Threads", "Thread #%i committed a segfault at address %p", cur->TID, Addr);
+       MM_DumpTables(0, USER_MAX);
        Threads_Fault( 1 );
        //Threads_Exit( 0, -1 );
 }
@@ -975,6 +1062,9 @@ void Threads_DumpActive(void)
                                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( thread->bInstrTrace )
+                               Log("  Tracing Enabled");
+                       Proc_DumpThreadCPUState(thread);
                }
        
        #if SCHEDULER_TYPE == SCHED_RR_PRI
@@ -1018,6 +1108,9 @@ void Threads_Dump(void)
                }
                Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
                Log("  KStack 0x%x", thread->KernelStack);
+               if( thread->bInstrTrace )
+                       Log("  Tracing Enabled");
+               Proc_DumpThreadCPUState(thread);
        }
 }
 
@@ -1038,13 +1131,13 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last)
        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
        //   DEFINITELY - free() can deadlock in this case
+       //   I'll do it when it becomes an issue
        while(gDeleteThreads)
        {
                thread = gDeleteThreads->Next;
@@ -1065,7 +1158,10 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last)
                }
                gDeleteThreads = thread;
        }
-       
+
+       // Make sure the current (well, old) thread is marked as de-scheduled   
+       if(Last)        Last->CurCPU = -1;
+
        // No active threads, just take a nap
        if(giNumActiveThreads == 0) {
                SHORTREL( &glThreadListLock );
@@ -1096,14 +1192,15 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last)
                        #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);
+                       LogF("Log: CPU%i released %p (%i %s) into the pool (%i [+%i] tickets in pool)\n",
+                               CPU, Last, Last->TID, Last->ThreadName, giFreeTickets,
+                               caiTICKET_COUNTS[ Last->Priority ]);
                        # endif
                        #endif
                }
                #if SCHEDULER_TYPE == SCHED_LOTTERY && DEBUG_TRACE_TICKETS
                else
-                       LogF(" CPU %i released %p (%i %s)->Status = %i (Released)\n",
+                       LogF("Log: CPU%i released %p (%i %s)->Status = %i (Released,not in pool)\n",
                                CPU, Last, Last->TID, Last->ThreadName, Last->Status);
                #endif
                Last->CurCPU = -1;
@@ -1162,12 +1259,13 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last)
                        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 ];
+               # if DEBUG_TRACE_TICKETS
+               LogF("Log: CPU%i allocated %p (%i %s), (%i [-%i] tickets in pool), \n",
+                       CPU, thread, thread->TID, thread->ThreadName,
+                       giFreeTickets, caiTICKET_COUNTS[ thread->Priority ]);
+               # endif
        }
        
        // ---
@@ -1184,7 +1282,7 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last)
                        }
                        // If we fall onto the same queue again, special handling is
                        // needed
-                       if( i == Last->Priority ) {
+                       if( Last && Last->Status == THREAD_STAT_ACTIVE && i == Last->Priority ) {
                                tThread *savedThread = thread;
                                
                                // Find the next unscheduled thread in the list
@@ -1205,6 +1303,9 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last)
                        SHORTREL(&glThreadListLock);
                        return NULL;
                }
+               if( thread->Status != THREAD_STAT_ACTIVE ) {
+                       LogF("Oops, Thread %i (%s) is not active\n", thread->TID, thread->ThreadName);
+               }
        }
        #elif SCHEDULER_TYPE == SCHED_RR_SIM
        {               
@@ -1234,22 +1335,14 @@ tThread *Threads_GetNextToRun(int CPU, tThread *Last)
        
        // Make the new thread non-schedulable
        thread->CurCPU = CPU;
+       thread->Remaining = thread->Quantum;
        
        SHORTREL( &glThreadListLock );
        
        return thread;
 }
 
-/**
- * \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.
- */
+// Acquire mutex (see mutex.h for documentation)
 int Mutex_Acquire(tMutex *Mutex)
 {
        tThread *us = Proc_GetCurThread();
@@ -1278,6 +1371,12 @@ int Mutex_Acquire(tMutex *Mutex)
                        Mutex->Waiting = us;
                        Mutex->LastWaiting = us;
                }
+               
+               #if DEBUG_TRACE_STATE
+               Log("%p (%i %s) waiting on mutex %p",
+                       us, us->TID, us->ThreadName, Mutex);
+               #endif
+               
                #if 0
                {
                         int    i = 0;
@@ -1309,10 +1408,7 @@ int Mutex_Acquire(tMutex *Mutex)
        return 0;
 }
 
-/**
- * \brief Release a held mutex
- * \param Mutex        Mutex to release
- */
+// Release a mutex
 void Mutex_Release(tMutex *Mutex)
 {
        SHORTLOCK( &Mutex->Protector );
@@ -1345,10 +1441,7 @@ void Mutex_Release(tMutex *Mutex)
        #endif
 }
 
-/**
- * \brief Is this mutex locked?
- * \param Mutex        Mutex pointer
- */
+// Check if a mutex is locked
 int Mutex_IsLocked(tMutex *Mutex)
 {
        return Mutex->Owner != NULL;
@@ -1359,9 +1452,11 @@ int Mutex_IsLocked(tMutex *Mutex)
 //
 void Semaphore_Init(tSemaphore *Sem, int Value, int MaxValue, const char *Module, const char *Name)
 {
+       memset(Sem, 0, sizeof(tSemaphore));
        Sem->Value = Value;
        Sem->ModName = Module;
        Sem->Name = Name;
+       Sem->MaxValue = MaxValue;
 }
 //
 // Wait for items to be avaliable
@@ -1385,7 +1480,6 @@ int Semaphore_Wait(tSemaphore *Sem, int MaxToTake)
                else
                        taken = Sem->Value;
                Sem->Value -= taken;
-               SHORTREL( &Sem->Protector );
        }
        else
        {
@@ -1409,10 +1503,16 @@ int Semaphore_Wait(tSemaphore *Sem, int MaxToTake)
                        Sem->LastWaiting = us;
                }
                
+               #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
+               Log("%p (%i %s) waiting on semaphore %p %s:%s",
+                       us, us->TID, us->ThreadName,
+                       Sem, Sem->ModName, Sem->Name);
+               #endif
+               
+               SHORTREL( &Sem->Protector );    // Release first to make sure it is released
                SHORTREL( &glThreadListLock );  
-               SHORTREL( &Sem->Protector );
                while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
-               // We're only woken when there's something avaliable
+               // We're only woken when there's something avaliable (or a signal arrives)
                us->WaitPointer = NULL;
                
                taken = us->RetStatus;
@@ -1440,6 +1540,13 @@ int Semaphore_Wait(tSemaphore *Sem, int MaxToTake)
                        given = Sem->MaxValue - Sem->Value;
                Sem->Value -= given;
                
+               
+               #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
+               Log("%p (%i %s) woken by wait on %p %s:%s",
+                       toWake, toWake->TID, toWake->ThreadName,
+                       Sem, Sem->ModName, Sem->Name);
+               #endif
+               
                // Save the number we gave to the thread's status
                toWake->RetStatus = given;
                
@@ -1472,8 +1579,12 @@ int Semaphore_Signal(tSemaphore *Sem, int AmmountToAdd)
        if( Sem->MaxValue && Sem->Value == Sem->MaxValue )
        {
                tThread *us;
-               SHORTLOCK( &glThreadListLock );
+               #if 0
+               Log_Debug("Threads", "Semaphore_Signal: IDLE Sem = %s:%s", Sem->ModName, Sem->Name);
+               Log_Debug("Threads", "Semaphore_Signal: Sem->Value(%i) == Sem->MaxValue(%i)", Sem->Value, Sem->MaxValue);
+               #endif
                
+               SHORTLOCK( &glThreadListLock );
                // - Remove from active list
                us = Threads_RemActive();
                us->Next = NULL;
@@ -1492,6 +1603,12 @@ int Semaphore_Signal(tSemaphore *Sem, int AmmountToAdd)
                        Sem->LastSignaling = us;
                }
                
+               #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
+               Log("%p (%i %s) signaling semaphore %p %s:%s",
+                       us, us->TID, us->ThreadName,
+                       Sem, Sem->ModName, Sem->Name);
+               #endif
+               
                SHORTREL( &glThreadListLock );  
                SHORTREL( &Sem->Protector );
                while(us->Status == THREAD_STAT_SEMAPHORESLEEP) Threads_Yield();
@@ -1520,12 +1637,13 @@ int Semaphore_Signal(tSemaphore *Sem, int AmmountToAdd)
        {
                tThread *toWake = Sem->Waiting;
                
+               // Remove thread from list (double ended, so clear LastWaiting if needed)
                Sem->Waiting = Sem->Waiting->Next;
-               // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
                if( Sem->Waiting == NULL )
                        Sem->LastWaiting = NULL;
                
-               // Figure out how much to give
+               // Figure out how much to give to woken thread
+               // - Requested count is stored in ->RetStatus
                if( toWake->RetStatus && Sem->Value > toWake->RetStatus )
                        given = toWake->RetStatus;
                else
@@ -1535,10 +1653,20 @@ int Semaphore_Signal(tSemaphore *Sem, int AmmountToAdd)
                // Save the number we gave to the thread's status
                toWake->RetStatus = given;
                
+               if(toWake->bInstrTrace)
+                       Log("%s(%i) given %i from %p", toWake->ThreadName, toWake->TID, given, Sem);
+               #if DEBUG_TRACE_STATE || SEMAPHORE_DEBUG
+               Log("%p (%i %s) woken by signal on %p %s:%s",
+                       toWake, toWake->TID, toWake->ThreadName,
+                       Sem, Sem->ModName, Sem->Name);
+               #endif
+               
                // Wake the sleeper
                SHORTLOCK( &glThreadListLock );
                if( toWake->Status != THREAD_STAT_ACTIVE )
                        Threads_AddActive(toWake);
+               else
+                       Warning("Thread %p (%i %s) is already awake", toWake, toWake->TID, toWake->ThreadName);
                SHORTREL( &glThreadListLock );
        }
        SHORTREL( &Sem->Protector );

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