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, int EventID)
  14 {
  15         if( EventID < 0 || EventID > N_EVENTS )
  16         {
  17                 return ;
  18         }
  19
  20         SHORTLOCK( Thread->IsLocked );
  21
  22         Thread->EventState |= 1 << EventID;
  23
  24         // Currently sleeping on an event?
  25         if( Thread->State == THREAD_STAT_EVENTSLEEP )
  26         {
  27                 // Waiting on this event?
  28                 if( (Uint32)Thread->RetStatus & (1 << EventID) )
  29                 {
  30                         // Wake up
  31                         Threads_AddActive(Thread);
  32                 }
  33         }
  34
  35         SHORTREL( Thread->IsLocked );
  36 }
  37
  38 Uint32 Threads_WaitEvents(Uint32 EventMask)
  39 {
  40         Uint32  rv;
  41         tThread *us = Proc_GetCurThread();
  42
  43         // Early return check
  44         if( EventMask == 0 )
  45         {
  46                 return 0;
  47         }
  48
  49         // Check if a wait is needed
  50         SHORTLOCK( &us->IsLocked );
  51         if( !(us->EventState & EventMask) )
  52         {
  53                 // Wait
  54                 us->RetStatus = EventMask;      // HACK: Store EventMask in RetStatus
  55                 SHORTLOCK( &glThreadListLock );
  56                 us = Threads_RemActive();
  57                 us->Status = THREAD_STAT_EVENTSLEEP;
  58                 SHORTREL( &glThreadListLock );
  59                 SHORTREL( &us->IsLocked );
  60                 while(us->Status == THREAD_STAT_MUTEXSLEEP)     Threads_Yield();
  61                 // Woken when lock is acquired
  62                 SHORTLOCK( &us->IsLocked );
  63         }
  64
  65         // Get return value and clear changed event bits
  66         rv = us->EventState & EventMask;
  67         us->EventState &= ~EventMask;
  68
  69         SHORTREL( us->IsLocked );
  70
  71         return rv;
  72 }
  73