KernelLand/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 #define QUEUENEXT(ptr)  (*( (void**)(ptr) + Queue->NextOffset/sizeof(void*) ))
  13
  14 // === CODE ===
  15 void Workqueue_Init(tWorkqueue *Queue, const char *Name, size_t NextOfset)
  16 {
  17         Queue->Name = Name;
  18         Queue->NextOffset = NextOfset;
  19 }
  20
  21 void *Workqueue_GetWork(tWorkqueue *Queue)
  22 {
  23         tThread *us;
  24
  25         for( ;; )
  26         {
  27                 // Check for work
  28                 SHORTLOCK(&Queue->Protector);
  29                 if(Queue->Head)
  30                 {
  31                         void *ret = Queue->Head;
  32                         Queue->Head = QUEUENEXT( ret );
  33                         if(Queue->Tail == ret)
  34                                 Queue->Tail = NULL;
  35                         SHORTREL(&Queue->Protector);
  36                         return ret;
  37                 }
  38
  39                 // Go to sleep
  40                 SHORTLOCK(&glThreadListLock);
  41                 us = Threads_RemActive();
  42                 us->WaitPointer = Queue;
  43                 us->Status = THREAD_STAT_QUEUESLEEP;
  44                 Queue->Sleeper = us;
  45                 SHORTREL(&Queue->Protector);
  46                 SHORTREL(&glThreadListLock);
  47
  48                 // Yield and sleep
  49                 Threads_Yield();
  50                 if(us->Status == THREAD_STAT_QUEUESLEEP) {
  51                         // Why are we awake?!
  52                 }
  53
  54                 us->WaitPointer = NULL;
  55         }
  56 }
  57
  58 void Workqueue_AddWork(tWorkqueue *Queue, void *Ptr)
  59 {
  60         SHORTLOCK(&Queue->Protector);
  61
  62         if( Queue->Tail )
  63                 QUEUENEXT(Queue->Tail) = Ptr;
  64         else
  65                 Queue->Head = Ptr;
  66         Queue->Tail = Ptr;
  67         QUEUENEXT(Ptr) = NULL;
  68
  69         if( Queue->Sleeper )
  70         {
  71                 if( Queue->Sleeper->Status != THREAD_STAT_ACTIVE )
  72                         Threads_AddActive(Queue->Sleeper);
  73                 Queue->Sleeper = NULL;
  74         }
  75         SHORTREL(&Queue->Protector);
  76 }