Kernel/workqueue.c

   1 /*
   2  * Acess2 Kernel
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * workqueue.c
   6  * - Worker FIFO Queue (Single Consumer, Interrupt Producer)
   7  */
   8 #include <acess.h>
   9 #include <workqueue.h>
  10 #include <threads_int.h>
  11
  12 // === CODE ===
  13 void Workqueue_Init(tWorkqueue *Queue, const char *Name, size_t NextOfset)
  14 {
  15         Queue->Name = Name;
  16         Queue->NextOffset = NextOfset;
  17 }
  18
  19 void *Workqueue_GetWork(tWorkqueue *Queue)
  20 {
  21         tThread *us;
  22
  23         for( ;; )
  24         {
  25                 // Check for work
  26                 SHORTLOCK(&Queue->Protector);
  27                 if(Queue->Head)
  28                 {
  29                         void *ret = Queue->Head;
  30                         Queue->Head = *( (void**)ret + Queue->NextOffset/sizeof(void*) );
  31                         if(Queue->Tail == ret)
  32                                 Queue->Tail = NULL;
  33                         SHORTREL(&Queue->Protector);
  34                         return ret;
  35                 }
  36
  37                 // Go to sleep
  38                 SHORTLOCK(&glThreadListLock);
  39                 us = Threads_RemActive();
  40                 us->WaitPointer = Queue;
  41                 us->Status = THREAD_STAT_QUEUESLEEP;
  42                 Queue->Sleeper = us;
  43                 SHORTREL(&Queue->Protector);
  44                 SHORTREL(&glThreadListLock);
  45
  46                 // Yield and sleep
  47                 Threads_Yield();
  48                 if(us->Status == THREAD_STAT_QUEUESLEEP) {
  49                         // Why are we awake?!
  50                 }
  51
  52                 us->WaitPointer = NULL;
  53         }
  54 }
  55
  56 void Workqueue_AddWork(tWorkqueue *Queue, void *Ptr)
  57 {
  58         SHORTLOCK(&Queue->Protector);
  59
  60         if( Queue->Tail )
  61                 *( (void**)Queue->Tail + Queue->NextOffset/sizeof(void*) ) = Ptr;
  62         else
  63                 Queue->Head = Ptr;
  64         Queue->Tail = Ptr;
  65
  66         if( Queue->Sleeper )
  67         {
  68                 if( Queue->Sleeper->Status != THREAD_STAT_ACTIVE )
  69                         Threads_AddActive(Queue->Sleeper);
  70                 Queue->Sleeper = NULL;
  71         }
  72         SHORTREL(&Queue->Protector);
  73 }