reactos/ntoskrnl/ex/work.c

   1 /*
   2  * COPYRIGHT:          See COPYING in the top level directory
   3  * PROJECT:            ReactOS kernel
   4  * FILE:               ntoskrnl/ex/work.c
   5  * PURPOSE:            Manage system work queues
   6  *
   7  * PROGRAMMERS:        Alex Ionescu - Used correct work queue array and added some fixes and checks.
   8  *                     Gunnar Dalsnes - Implemented
   9  */
  10
  11 /* INCLUDES ******************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 #if defined (ALLOC_PRAGMA)
  18 #pragma alloc_text(INIT, ExpInitializeWorkerThreads)
  19 #endif
  20
  21 /* DEFINES *******************************************************************/
  22
  23 #define NUMBER_OF_WORKER_THREADS   (5)
  24
  25 /* TYPES *********************************************************************/
  26
  27 /* GLOBALS *******************************************************************/
  28
  29 /*
  30  * PURPOSE: Queue of items waiting to be processed at normal priority
  31  */
  32 EX_WORK_QUEUE ExWorkerQueue[MaximumWorkQueue];
  33
  34 /* FUNCTIONS ****************************************************************/
  35
  36 /*
  37  * FUNCTION: Entry point for a worker thread
  38  * ARGUMENTS:
  39  *         context = Parameters
  40  * RETURNS: Status
  41  * NOTE: To kill a worker thread you must queue an item whose callback
  42  * calls PsTerminateSystemThread
  43  */
  44 static
  45 VOID
  46 STDCALL
  47 ExpWorkerThreadEntryPoint(IN PVOID Context)
  48 {
  49     PWORK_QUEUE_ITEM WorkItem;
  50     PLIST_ENTRY QueueEntry;
  51     WORK_QUEUE_TYPE WorkQueueType;
  52     PEX_WORK_QUEUE WorkQueue;
  53
  54     /* Get Queue Type and Worker Queue */
  55     WorkQueueType = (WORK_QUEUE_TYPE)Context;
  56     WorkQueue = &ExWorkerQueue[WorkQueueType];
  57
  58     /* Loop forever */
  59     while (TRUE) {
  60
  61         /* Wait for Something to Happen on the Queue */
  62         QueueEntry = KeRemoveQueue(&WorkQueue->WorkerQueue, KernelMode, NULL);
  63
  64         /* Can't happen since we do a KernelMode wait (and we're a system thread) */
  65         ASSERT((NTSTATUS)QueueEntry != STATUS_USER_APC);
  66
  67         /* this should never happen either, since we wait with NULL timeout,
  68          * but there's a slight possibility that STATUS_TIMEOUT is returned
  69          * at queue rundown in NT (unlikely) -Gunnar
  70          */
  71         ASSERT((NTSTATUS)QueueEntry != STATUS_TIMEOUT);
  72
  73         /* Increment Processed Work Items */
  74         InterlockedIncrement((PLONG)&WorkQueue->WorkItemsProcessed);
  75
  76         /* Get the Work Item */
  77         WorkItem = CONTAINING_RECORD(QueueEntry, WORK_QUEUE_ITEM, List);
  78
  79         /* Call the Worker Routine */
  80         WorkItem->WorkerRoutine(WorkItem->Parameter);
  81
  82         /* Make sure it returned at right IRQL */
  83         if (KeGetCurrentIrql() != PASSIVE_LEVEL) {
  84
  85             KEBUGCHECKEX(WORKER_THREAD_RETURNED_AT_BAD_IRQL,
  86                          (ULONG_PTR)WorkItem->WorkerRoutine,
  87                          KeGetCurrentIrql(),
  88                          (ULONG_PTR)WorkItem->Parameter,
  89                          (ULONG_PTR)WorkItem);
  90         }
  91
  92         /* Make sure it returned with Impersionation Disabled */
  93         if (PsGetCurrentThread()->ActiveImpersonationInfo) {
  94
  95             KEBUGCHECKEX(IMPERSONATING_WORKER_THREAD,
  96                          (ULONG_PTR)WorkItem->WorkerRoutine,
  97                          (ULONG_PTR)WorkItem->Parameter,
  98                          (ULONG_PTR)WorkItem,
  99                          0);
 100         }
 101     }
 102 }
 103
 104 static
 105 VOID
 106 STDCALL
 107 ExpInitializeWorkQueue(WORK_QUEUE_TYPE WorkQueueType,
 108                        KPRIORITY Priority)
 109 {
 110     ULONG i;
 111     PETHREAD Thread;
 112     HANDLE hThread;
 113
 114     /* Loop through how many threads we need to create */
 115     for (i = 0; i < NUMBER_OF_WORKER_THREADS; i++) {
 116
 117         /* Create the System Thread */
 118         PsCreateSystemThread(&hThread,
 119                              THREAD_ALL_ACCESS,
 120                              NULL,
 121                              NULL,
 122                              NULL,
 123                              ExpWorkerThreadEntryPoint,
 124                              (PVOID)WorkQueueType);
 125
 126         /* Get the Thread */
 127         ObReferenceObjectByHandle(hThread,
 128                                   THREAD_SET_INFORMATION,
 129                                   PsThreadType,
 130                                   KernelMode,
 131                                   (PVOID*)&Thread,
 132                                   NULL);
 133
 134         /* Set the Priority */
 135         KeSetPriorityThread(&Thread->Tcb, Priority);
 136
 137         /* Dereference and close handle */
 138         ObDereferenceObject(Thread);
 139         ZwClose(hThread);
 140     }
 141 }
 142
 143 VOID
 144 INIT_FUNCTION
 145 STDCALL
 146 ExpInitializeWorkerThreads(VOID)
 147 {
 148     ULONG WorkQueueType;
 149
 150     /* Initialize the Array */
 151     for (WorkQueueType = 0; WorkQueueType < MaximumWorkQueue; WorkQueueType++) {
 152
 153         RtlZeroMemory(&ExWorkerQueue[WorkQueueType], sizeof(EX_WORK_QUEUE));
 154         KeInitializeQueue(&ExWorkerQueue[WorkQueueType].WorkerQueue, 0);
 155     }
 156
 157     /* Create the built-in worker threads for each work queue */
 158     ExpInitializeWorkQueue(CriticalWorkQueue, LOW_REALTIME_PRIORITY);
 159     ExpInitializeWorkQueue(DelayedWorkQueue, LOW_PRIORITY);
 160     ExpInitializeWorkQueue(HyperCriticalWorkQueue, HIGH_PRIORITY);
 161 }
 162
 163 /*
 164  * @implemented
 165  *
 166  * FUNCTION: Inserts a work item in a queue for one of the system worker
 167  * threads to process
 168  * ARGUMENTS:
 169  *        WorkItem = Item to insert
 170  *        QueueType = Queue to insert it in
 171  */
 172 VOID
 173 STDCALL
 174 ExQueueWorkItem(PWORK_QUEUE_ITEM WorkItem,
 175                 WORK_QUEUE_TYPE QueueType)
 176 {
 177     ASSERT(WorkItem!=NULL);
 178     ASSERT_IRQL(DISPATCH_LEVEL);
 179     ASSERT(WorkItem->List.Flink == NULL);
 180
 181     /* Insert the Queue */
 182     KeInsertQueue(&ExWorkerQueue[QueueType].WorkerQueue, &WorkItem->List);
 183 }
 184
 185 /* EOF */