Kernel/events.c

   1 /*
   2  * Acess2 Kernel
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * events.c
   6  * - Thread level event handling
   7  */
   8 #include <acess.h>
   9 #include <threads_int.h>
  10 #include <events.h>
  11
  12 // === CODE ===
  13 void Threads_PostEvent(tThread *Thread, Uint32 EventMask)
  14 {
  15         // Sanity checking
  16         if( !Thread )   return ;
  17         if( EventMask == 0 )    return ;
  18         // TODO: Check that only one bit is set?
  19
  20         SHORTLOCK( &Thread->IsLocked );
  21
  22         Thread->EventState |= EventMask;
  23
  24         // Currently sleeping on an event?
  25         if( Thread->Status == THREAD_STAT_EVENTSLEEP )
  26         {
  27                 // Waiting on this event?
  28                 if( (Uint32)Thread->RetStatus & EventMask )
  29                 {
  30                         // Wake up
  31                         // TODO: Does it matter if the thread is locked here?
  32                         Threads_AddActive(Thread);
  33                 }
  34         }
  35
  36         SHORTREL( &Thread->IsLocked );
  37 }
  38
  39 /**
  40  * \brief Wait for an event to occur
  41  */
  42 Uint32 Threads_WaitEvents(Uint32 EventMask)
  43 {
  44         Uint32  rv;
  45         tThread *us = Proc_GetCurThread();
  46
  47         // Early return check
  48         if( EventMask == 0 )
  49         {
  50                 return 0;
  51         }
  52
  53         // Check if a wait is needed
  54         SHORTLOCK( &us->IsLocked );
  55         while( !(us->EventState & EventMask) )
  56         {
  57                 // Wait
  58                 us->RetStatus = EventMask;      // HACK: Store EventMask in RetStatus
  59                 SHORTLOCK( &glThreadListLock );
  60                 us = Threads_RemActive();
  61                 us->Status = THREAD_STAT_EVENTSLEEP;
  62                 SHORTREL( &glThreadListLock );
  63                 SHORTREL( &us->IsLocked );
  64                 while(us->Status == THREAD_STAT_MUTEXSLEEP)     Threads_Yield();
  65                 // Woken when lock is acquired
  66                 SHORTLOCK( &us->IsLocked );
  67         }
  68
  69         // Get return value and clear changed event bits
  70         rv = us->EventState & EventMask;
  71         us->EventState &= ~EventMask;
  72
  73         SHORTREL( &us->IsLocked );
  74
  75         return rv;
  76 }
  77