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         Queue->Sleeper = NULL;
  20         Queue->SleepTail = NULL;
  21 }
  22
  23 void *Workqueue_GetWork(tWorkqueue *Queue)
  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                 Threads_int_Sleep(THREAD_STAT_QUEUESLEEP,
  40                         Queue, 0,
  41                         &Queue->Sleeper, &Queue->SleepTail, &Queue->Protector);
  42         }
  43 }
  44
  45 void Workqueue_AddWork(tWorkqueue *Queue, void *Ptr)
  46 {
  47         SHORTLOCK(&Queue->Protector);
  48
  49         if( Queue->Tail )
  50                 QUEUENEXT(Queue->Tail) = Ptr;
  51         else
  52                 Queue->Head = Ptr;
  53         Queue->Tail = Ptr;
  54         QUEUENEXT(Ptr) = NULL;
  55
  56         if( Queue->Sleeper )
  57         {
  58                 ASSERTC( Queue->Sleeper->Status, !=, THREAD_STAT_ACTIVE );
  59                 tThread *next_sleeper = Queue->Sleeper->Next;
  60                 Threads_AddActive(Queue->Sleeper);
  61                 Queue->Sleeper = next_sleeper;
  62                 if(!next_sleeper)
  63                         Queue->SleepTail = NULL;
  64         }
  65         SHORTREL(&Queue->Protector);
  66 }