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         // TODO: Check that only one bit is set?
  16         if( EventMask == 0 )    return ;
  17
  18         SHORTLOCK( &Thread->IsLocked );
  19
  20         Thread->EventState |= EventMask;
  21
  22         // Currently sleeping on an event?
  23         if( Thread->Status == THREAD_STAT_EVENTSLEEP )
  24         {
  25                 // Waiting on this event?
  26                 if( (Uint32)Thread->RetStatus & EventMask )
  27                 {
  28                         // Wake up
  29                         // TODO: Does it matter if the thread is locked here?
  30                         Threads_AddActive(Thread);
  31                 }
  32         }
  33
  34         SHORTREL( &Thread->IsLocked );
  35 }
  36
  37 Uint32 Threads_WaitEvents(Uint32 EventMask)
  38 {
  39         Uint32  rv;
  40         tThread *us = Proc_GetCurThread();
  41
  42         // Early return check
  43         if( EventMask == 0 )
  44         {
  45                 return 0;
  46         }
  47
  48         // Check if a wait is needed
  49         SHORTLOCK( &us->IsLocked );
  50         if( !(us->EventState & EventMask) )
  51         {
  52                 // Wait
  53                 us->RetStatus = EventMask;      // HACK: Store EventMask in RetStatus
  54                 SHORTLOCK( &glThreadListLock );
  55                 us = Threads_RemActive();
  56                 us->Status = THREAD_STAT_EVENTSLEEP;
  57                 SHORTREL( &glThreadListLock );
  58                 SHORTREL( &us->IsLocked );
  59                 while(us->Status == THREAD_STAT_MUTEXSLEEP)     Threads_Yield();
  60                 // Woken when lock is acquired
  61                 SHORTLOCK( &us->IsLocked );
  62         }
  63
  64         // Get return value and clear changed event bits
  65         rv = us->EventState & EventMask;
  66         us->EventState &= ~EventMask;
  67
  68         SHORTREL( &us->IsLocked );
  69
  70         return rv;
  71 }
  72