reactos/ntoskrnl/ke/gate.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS Kernel
   4  * FILE:            ntoskrnl/ke/gate.c
   5  * PURPOSE:         Implements the Gate Dispatcher Object
   6  *
   7  * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
   8  */
   9
  10 /* INCLUDES *****************************************************************/
  11
  12 #include <ntoskrnl.h>
  13 #define NDEBUG
  14 #include <internal/debug.h>
  15
  16 /* FUNCTIONS ****************************************************************/
  17
  18 VOID
  19 FASTCALL
  20 KeInitializeGate(PKGATE Gate)
  21 {
  22     DPRINT("KeInitializeGate(Gate %x)\n", Gate);
  23
  24     /* Initialize the Dispatcher Header */
  25     KeInitializeDispatcherHeader(&Gate->Header,
  26                                  GateObject,
  27                                  sizeof(Gate) / sizeof(ULONG),
  28                                  0);
  29 }
  30
  31 VOID
  32 FASTCALL
  33 KeWaitForGate(PKGATE Gate,
  34               KWAIT_REASON WaitReason,
  35               KPROCESSOR_MODE WaitMode)
  36 {
  37     KIRQL OldIrql;
  38     PKTHREAD CurrentThread = KeGetCurrentThread();
  39     PKWAIT_BLOCK GateWaitBlock;
  40     NTSTATUS Status;
  41
  42     DPRINT("KeWaitForGate(Gate %x)\n", Gate);
  43
  44     do
  45     {
  46         /* Lock the APC Queue */
  47         OldIrql = KeAcquireDispatcherDatabaseLock();
  48
  49         /* Check if it's already signaled */
  50         if (Gate->Header.SignalState)
  51         {
  52             /* Unsignal it */
  53             Gate->Header.SignalState = 0;
  54
  55             /* Unlock the Queue and return */
  56             KeReleaseDispatcherDatabaseLock(OldIrql);
  57             return;
  58         }
  59
  60         /* Setup a Wait Block */
  61         GateWaitBlock = &CurrentThread->WaitBlock[0];
  62         GateWaitBlock->Object = (PVOID)Gate;
  63         GateWaitBlock->Thread = CurrentThread;
  64
  65         /* Set the Thread Wait Data */
  66         CurrentThread->WaitReason = WaitReason;
  67         CurrentThread->WaitMode = WaitMode;
  68         CurrentThread->WaitIrql = OldIrql;
  69         CurrentThread->GateObject = Gate;
  70
  71         /* Insert into the Wait List */
  72         InsertTailList(&Gate->Header.WaitListHead, &GateWaitBlock->WaitListEntry);
  73
  74         /* Handle Kernel Queues */
  75         if (CurrentThread->Queue)
  76         {
  77             DPRINT("Waking Queue\n");
  78             KiWakeQueue(CurrentThread->Queue);
  79         }
  80
  81         /* Block the Thread */
  82         DPRINT("Blocking the Thread: %x\n", CurrentThread);
  83         KiBlockThread(&Status,
  84                       CurrentThread->Alertable,
  85                       WaitMode,
  86                       WaitReason);
  87
  88         /* Check if we were executing an APC */
  89         if (Status != STATUS_KERNEL_APC) return;
  90
  91         DPRINT("Looping Again\n");
  92     } while (TRUE);
  93 }
  94
  95 VOID
  96 FASTCALL
  97 KeSignalGateBoostPriority(PKGATE Gate)
  98 {
  99     PKTHREAD WaitThread;
 100     PKWAIT_BLOCK WaitBlock;
 101     KIRQL OldIrql;
 102     NTSTATUS WaitStatus = STATUS_SUCCESS;
 103
 104     DPRINT("KeSignalGateBoostPriority(EveGate %x)\n", Gate);
 105
 106     /* Acquire Dispatcher Database Lock */
 107     OldIrql = KeAcquireDispatcherDatabaseLock();
 108
 109     /* Make sure we're not already signaled or that the list is empty */
 110     if (Gate->Header.SignalState) goto quit;
 111
 112     /* If our wait list is empty, then signal the event and return */
 113     if (IsListEmpty(&Gate->Header.WaitListHead))
 114     {
 115         Gate->Header.SignalState = 1;
 116         goto quit;
 117     }
 118
 119     /* Get WaitBlock */
 120     WaitBlock = CONTAINING_RECORD(Gate->Header.WaitListHead.Flink,
 121                                   KWAIT_BLOCK,
 122                                   WaitListEntry);
 123     /* Remove it */
 124     RemoveEntryList(&WaitBlock->WaitListEntry);
 125
 126     /* Get the Associated thread */
 127     WaitThread = WaitBlock->Thread;
 128
 129     /* Increment the Queue's active threads */
 130     if (WaitThread->Queue)
 131     {
 132         DPRINT("Incrementing Queue's active threads\n");
 133         WaitThread->Queue->CurrentCount++;
 134     }
 135
 136     /* Reschedule the Thread */
 137     DPRINT("Unblocking the Thread\n");
 138     KiUnblockThread(WaitThread, &WaitStatus, EVENT_INCREMENT);
 139     return;
 140
 141 quit:
 142     /* Release the Dispatcher Database Lock */
 143     KeReleaseDispatcherDatabaseLock(OldIrql);
 144 }
 145
 146 /* EOF */