reactos/ntoskrnl/ex/work.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:          See COPYING in the top level directory
   4  * PROJECT:            ReactOS kernel
   5  * FILE:               ntoskrnl/ex/work.c
   6  * PURPOSE:            Manage system work queues
   7  *
   8  * PROGRAMMERS:        David Welch (welch@mcmail.com)
   9  */
  10
  11 /* INCLUDES ******************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 /* DEFINES *******************************************************************/
  18
  19 #define NUMBER_OF_WORKER_THREADS   (5)
  20
  21 /* TYPES *********************************************************************/
  22
  23 /* GLOBALS *******************************************************************/
  24
  25 /*
  26  * PURPOSE: Queue of items waiting to be processed at normal priority
  27  */
  28 KQUEUE EiNormalWorkQueue;
  29
  30 KQUEUE EiCriticalWorkQueue;
  31
  32 KQUEUE EiHyperCriticalWorkQueue;
  33
  34 /* FUNCTIONS ****************************************************************/
  35
  36 //static NTSTATUS STDCALL
  37 static VOID STDCALL
  38 ExWorkerThreadEntryPoint(IN PVOID context)
  39 /*
  40  * FUNCTION: Entry point for a worker thread
  41  * ARGUMENTS:
  42  *         context = Parameters
  43  * RETURNS: Status
  44  * NOTE: To kill a worker thread you must queue an item whose callback
  45  * calls PsTerminateSystemThread
  46  */
  47 {
  48
  49    PWORK_QUEUE_ITEM item;
  50    PLIST_ENTRY current;
  51
  52    while (TRUE)
  53    {
  54       current = KeRemoveQueue( (PKQUEUE)context, KernelMode, NULL );
  55
  56       /* can't happend since we do a KernelMode wait (and we're a system thread) */
  57       ASSERT((NTSTATUS)current != STATUS_USER_APC);
  58
  59       /* this should never happend either, since we wait with NULL timeout,
  60        * but there's a slight possibility that STATUS_TIMEOUT is returned
  61        * at queue rundown in NT (unlikely) -Gunnar
  62        */
  63       ASSERT((NTSTATUS)current != STATUS_TIMEOUT);
  64
  65       /* based on INVALID_WORK_QUEUE_ITEM bugcheck desc. */
  66       if (current->Flink == NULL || current->Blink == NULL)
  67       {
  68          KeBugCheck(INVALID_WORK_QUEUE_ITEM);
  69       }
  70
  71       /* "reinitialize" item (same as done in ExInitializeWorkItem) */
  72       current->Flink = NULL;
  73
  74       item = CONTAINING_RECORD( current, WORK_QUEUE_ITEM, List);
  75       item->WorkerRoutine(item->Parameter);
  76
  77       if (KeGetCurrentIrql() != PASSIVE_LEVEL)
  78       {
  79          KeBugCheck(IRQL_NOT_LESS_OR_EQUAL);
  80       }
  81    }
  82
  83 }
  84
  85 static VOID ExInitializeWorkQueue(PKQUEUE WorkQueue,
  86                                   KPRIORITY Priority)
  87 {
  88    ULONG i;
  89    PETHREAD Thread;
  90    HANDLE   hThread;
  91
  92
  93    for (i=0; i<NUMBER_OF_WORKER_THREADS; i++)
  94      {
  95
  96    PsCreateSystemThread(&hThread,
  97                              THREAD_ALL_ACCESS,
  98                              NULL,
  99                              NULL,
 100                              NULL,
 101                              ExWorkerThreadEntryPoint,
 102               WorkQueue);
 103    ObReferenceObjectByHandle(hThread,
 104                                   THREAD_ALL_ACCESS,
 105                                   PsThreadType,
 106                                   KernelMode,
 107                                   (PVOID*)&Thread,
 108                                   NULL);
 109         KeSetPriorityThread(&Thread->Tcb,
 110                             Priority);
 111         ObDereferenceObject(Thread);
 112    ZwClose(hThread);
 113      }
 114 }
 115
 116 VOID INIT_FUNCTION
 117 ExInitializeWorkerThreads(VOID)
 118 {
 119    KeInitializeQueue( &EiNormalWorkQueue, NUMBER_OF_WORKER_THREADS );
 120    KeInitializeQueue( &EiCriticalWorkQueue , NUMBER_OF_WORKER_THREADS );
 121    KeInitializeQueue( &EiHyperCriticalWorkQueue , NUMBER_OF_WORKER_THREADS );
 122
 123    ExInitializeWorkQueue(&EiNormalWorkQueue,
 124                          LOW_PRIORITY);
 125    ExInitializeWorkQueue(&EiCriticalWorkQueue,
 126                          LOW_REALTIME_PRIORITY);
 127    ExInitializeWorkQueue(&EiHyperCriticalWorkQueue,
 128                          HIGH_PRIORITY);
 129 }
 130
 131 /*
 132  * @implemented
 133  */
 134 VOID STDCALL
 135 ExQueueWorkItem (PWORK_QUEUE_ITEM       WorkItem,
 136                  WORK_QUEUE_TYPE                QueueType)
 137 /*
 138  * FUNCTION: Inserts a work item in a queue for one of the system worker
 139  * threads to process
 140  * ARGUMENTS:
 141  *        WorkItem = Item to insert
 142  *        QueueType = Queue to insert it in
 143  */
 144 {
 145     ASSERT(WorkItem!=NULL);
 146     ASSERT_IRQL(DISPATCH_LEVEL);
 147     ASSERT(WorkItem->List.Flink == NULL);
 148    /*
 149     * Insert the item in the appropiate queue and wake up any thread
 150     * waiting for something to do
 151     */
 152     switch(QueueType)
 153     {
 154     case DelayedWorkQueue:
 155       KeInsertQueue (
 156           &EiNormalWorkQueue,
 157           &WorkItem->List
 158             );
 159         break;
 160
 161     case CriticalWorkQueue:
 162             KeInsertQueue (
 163               &EiCriticalWorkQueue,
 164               &WorkItem->List
 165               );
 166             break;
 167
 168     case HyperCriticalWorkQueue:
 169             KeInsertQueue (
 170              &EiHyperCriticalWorkQueue,
 171              &WorkItem->List
 172              );
 173                 break;
 174
 175     default:
 176         break;
 177
 178     }
 179 }
 180
 181 /* EOF */