KernelLand/Kernel/events.c

   1 /*
   2  * Acess2 Kernel
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * events.c
   6  * - Thread level event handling
   7  */
   8 #define DEBUG   0
   9 #include <acess.h>
  10 #include <events.h>
  11 #include <threads_int.h>
  12
  13 // === CODE ===
  14 void Threads_PostEvent(tThread *Thread, Uint32 EventMask)
  15 {
  16         // Sanity checking
  17         if( !Thread )   return ;
  18         if( EventMask == 0 )    return ;
  19         // TODO: Check that only one bit is set?
  20
  21         ENTER("pThread xEventMask", Thread, EventMask);
  22
  23         SHORTLOCK( &Thread->IsLocked );
  24
  25         Thread->EventState |= EventMask;
  26         LOG("Thread->EventState = 0x%x", Thread->EventState);
  27
  28         // Currently sleeping on an event?
  29         switch(Thread->Status)
  30         {
  31         // Waiting on this event?
  32         case THREAD_STAT_EVENTSLEEP:
  33                 if( (Uint32)Thread->RetStatus & EventMask )
  34                 {
  35                         // Wake up
  36                         LOG("Waking thread %p(%i %s)", Thread, Thread->TID, Thread->ThreadName);
  37                         Threads_AddActive(Thread);
  38                 }
  39                 break;
  40         case THREAD_STAT_SEMAPHORESLEEP:
  41                 if( EventMask & THREAD_EVENT_TIMER )
  42                 {
  43                         LOG("Waking %p(%i %s) from semaphore on timer",
  44                                 Thread, Thread->TID, Thread->ThreadName);
  45                         Semaphore_ForceWake(Thread);
  46                 }
  47                 break;
  48         default:
  49                 break;
  50         }
  51
  52         SHORTREL( &Thread->IsLocked );
  53         LEAVE('-');
  54 }
  55
  56 /**
  57  * \brief Clear an event without waiting
  58  */
  59 void Threads_ClearEvent(Uint32 EventMask)
  60 {
  61         Proc_GetCurThread()->EventState &= ~EventMask;
  62 }
  63
  64 /**
  65  * \brief Wait for an event to occur
  66  */
  67 Uint32 Threads_WaitEvents(Uint32 EventMask)
  68 {
  69         Uint32  rv;
  70         tThread *us = Proc_GetCurThread();
  71
  72         ENTER("xEventMask", EventMask);
  73
  74         // Early return check
  75         if( EventMask == 0 )
  76         {
  77                 LEAVE('i', 0);
  78                 return 0;
  79         }
  80
  81         LOG("us = %p(%i %s)", us, us->TID, us->ThreadName);
  82
  83         // Check if a wait is needed
  84         SHORTLOCK( &us->IsLocked );
  85         LOG("Locked and preparing for wait");
  86         if( (us->EventState & EventMask) == 0 )
  87         {
  88                 Threads_int_Sleep(THREAD_STAT_EVENTSLEEP, NULL, EventMask,
  89                         &us, NULL, &us->IsLocked);
  90                 // Woken when an event fires
  91                 SHORTLOCK( &us->IsLocked );
  92         }
  93
  94         // Get return value and clear changed event bits
  95         rv = us->EventState & EventMask;
  96         us->EventState &= ~EventMask;
  97
  98         SHORTREL( &us->IsLocked );
  99
 100         LEAVE('x', rv);
 101         return rv;
 102 }
 103