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->WaitIrql = OldIrql;
  67         CurrentThread->GateObject = Gate;
  68
  69         /* Insert into the Wait List */
  70         InsertTailList(&Gate->Header.WaitListHead,
  71                        &GateWaitBlock->WaitListEntry);
  72
  73         /* Handle Kernel Queues */
  74         if (CurrentThread->Queue)
  75         {
  76             DPRINT("Waking Queue\n");
  77             KiWakeQueue(CurrentThread->Queue);
  78         }
  79
  80         /* Setup the wait information */
  81         CurrentThread->WaitMode = WaitMode;
  82         CurrentThread->WaitReason = WaitReason;
  83         CurrentThread->WaitTime = ((PLARGE_INTEGER)&KeTickCount)->LowPart;
  84         CurrentThread->State = Waiting;
  85
  86         /* Find a new thread to run */
  87         DPRINT("Swapping threads\n");
  88         Status = KiSwapThread();
  89
  90         /* Check if we were executing an APC */
  91         if (Status != STATUS_KERNEL_APC) return;
  92
  93         DPRINT("Looping Again\n");
  94     } while (TRUE);
  95 }
  96
  97 VOID
  98 FASTCALL
  99 KeSignalGateBoostPriority(PKGATE Gate)
 100 {
 101     PKTHREAD WaitThread;
 102     PKWAIT_BLOCK WaitBlock;
 103     KIRQL OldIrql;
 104     NTSTATUS WaitStatus = STATUS_SUCCESS;
 105
 106     DPRINT("KeSignalGateBoostPriority(EveGate %x)\n", Gate);
 107
 108     /* Acquire Dispatcher Database Lock */
 109     OldIrql = KeAcquireDispatcherDatabaseLock();
 110
 111     /* Make sure we're not already signaled or that the list is empty */
 112     if (Gate->Header.SignalState) goto quit;
 113
 114     /* If our wait list is empty, then signal the event and return */
 115     if (IsListEmpty(&Gate->Header.WaitListHead))
 116     {
 117         Gate->Header.SignalState = 1;
 118         goto quit;
 119     }
 120
 121     /* Get WaitBlock */
 122     WaitBlock = CONTAINING_RECORD(Gate->Header.WaitListHead.Flink,
 123                                   KWAIT_BLOCK,
 124                                   WaitListEntry);
 125     /* Remove it */
 126     RemoveEntryList(&WaitBlock->WaitListEntry);
 127
 128     /* Get the Associated thread */
 129     WaitThread = WaitBlock->Thread;
 130
 131     /* Increment the Queue's active threads */
 132     if (WaitThread->Queue)
 133     {
 134         DPRINT("Incrementing Queue's active threads\n");
 135         WaitThread->Queue->CurrentCount++;
 136     }
 137
 138     /* Reschedule the Thread */
 139     DPRINT("Unblocking the Thread\n");
 140     KiUnblockThread(WaitThread, &WaitStatus, EVENT_INCREMENT);
 141     return;
 142
 143 quit:
 144     /* Release the Dispatcher Database Lock */
 145     KeReleaseDispatcherDatabaseLock(OldIrql);
 146 }
 147
 148 /* EOF */