848 lines
22 KiB
C
848 lines
22 KiB
C
/*++
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Copyright (c) 1993 Microsoft Corporation
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Module Name:
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queueobj.c
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Abstract:
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This module implements the kernel queue object. Functions are
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provided to initialize, read, insert, and remove queue objects.
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Author:
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David N. Cutler (davec) 31-Dec-1993
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Environment:
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Kernel mode only.
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Revision History:
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--*/
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#include "ki.h"
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//
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// The following assert macro is used to check that an input event is
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// really a kernel event and not something else, like deallocated pool.
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//
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#define ASSERT_QUEUE(Q) ASSERT((Q)->Header.Type == QueueObject);
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VOID
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KeInitializeQueue (
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IN PRKQUEUE Queue,
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IN ULONG Count OPTIONAL
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)
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/*++
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Routine Description:
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This function initializes a kernel queue object.
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Arguments:
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Queue - Supplies a pointer to a dispatcher object of type event.
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Count - Supplies the target maximum number of threads that should
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be concurrently active. If this parameter is not specified,
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then the number of processors is used.
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Return Value:
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None.
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--*/
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{
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//
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// Initialize standard dispatcher object header and set initial
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// state of queue object.
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//
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Queue->Header.Type = QueueObject;
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Queue->Header.Size = sizeof(KQUEUE) / sizeof(LONG);
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Queue->Header.SignalState = 0;
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InitializeListHead(&Queue->Header.WaitListHead);
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//
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// Initialize queue listhead, the thread list head, the current number
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// of threads, and the target maximum number of threads.
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//
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InitializeListHead(&Queue->EntryListHead);
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InitializeListHead(&Queue->ThreadListHead);
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Queue->CurrentCount = 0;
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if (ARGUMENT_PRESENT((PVOID)(ULONG_PTR)Count)) {
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Queue->MaximumCount = Count;
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} else {
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Queue->MaximumCount = KeNumberProcessors;
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}
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return;
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}
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LONG
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KeReadStateQueue (
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IN PRKQUEUE Queue
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)
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/*++
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Routine Description:
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This function reads the current signal state of a Queue object.
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Arguments:
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Queue - Supplies a pointer to a dispatcher object of type Queue.
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Return Value:
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The current signal state of the Queue object.
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--*/
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{
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ASSERT_QUEUE(Queue);
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//
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// Return current signal state of Queue object.
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//
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return Queue->Header.SignalState;
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}
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LONG
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KeInsertQueue (
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IN PRKQUEUE Queue,
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IN PLIST_ENTRY Entry
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)
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/*++
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Routine Description:
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This function inserts the specified entry in the queue object entry
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list and attempts to satisfy the wait of a single waiter.
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N.B. The wait discipline for Queue object is LIFO.
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Arguments:
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Queue - Supplies a pointer to a dispatcher object of type Queue.
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Entry - Supplies a pointer to a list entry that is inserted in the
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queue object entry list.
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Return Value:
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The previous signal state of the Queue object.
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--*/
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{
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KIRQL OldIrql;
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LONG OldState;
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ASSERT_QUEUE(Queue);
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ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
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//
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// Raise IRQL to dispatcher level and lock dispatcher database.
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//
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KiLockDispatcherDatabase(&OldIrql);
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//
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// Insert the specified entry in the queue object entry list.
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//
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OldState = KiInsertQueue(Queue, Entry, FALSE);
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//
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// Unlock the dispather database, lower IRQL to the previous level, and
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// return signal state of Queue object.
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//
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KiUnlockDispatcherDatabase(OldIrql);
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return OldState;
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}
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LONG
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KeInsertHeadQueue (
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IN PRKQUEUE Queue,
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IN PLIST_ENTRY Entry
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)
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/*++
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Routine Description:
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This function inserts the specified entry in the queue object entry
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list and attempts to satisfy the wait of a single waiter.
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N.B. The wait discipline for Queue object is LIFO.
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Arguments:
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Queue - Supplies a pointer to a dispatcher object of type Queue.
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Entry - Supplies a pointer to a list entry that is inserted in the
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queue object entry list.
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Return Value:
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The previous signal state of the Queue object.
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--*/
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{
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KIRQL OldIrql;
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LONG OldState;
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ASSERT_QUEUE(Queue);
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ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
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//
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// Raise IRQL to dispatcher level and lock dispatcher database.
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//
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KiLockDispatcherDatabase(&OldIrql);
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//
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// Insert the specified entry in the queue object entry list.
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//
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OldState = KiInsertQueue(Queue, Entry, TRUE);
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//
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// Unlock the dispather database, lower IRQL to the previous level, and
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// return signal state of Queue object.
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//
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KiUnlockDispatcherDatabase(OldIrql);
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return OldState;
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}
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//
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// The following macro initializes thread local variables for the wait
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// for single object kernel service while context switching is disabled.
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//
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// N.B. IRQL must be raised to DPC level prior to the invocation of this
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// macro.
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//
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// N.B. Initialization is done in this manner so this code does not get
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// executed inside the dispatcher lock.
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//
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#define InitializeRemoveQueue() \
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Thread->WaitBlockList = WaitBlock; \
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WaitBlock->Object = (PVOID)Queue; \
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WaitBlock->WaitKey = (CSHORT)(STATUS_SUCCESS); \
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WaitBlock->WaitType = WaitAny; \
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WaitBlock->Thread = Thread; \
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Thread->WaitStatus = 0; \
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if (ARGUMENT_PRESENT(Timeout)) { \
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WaitBlock->NextWaitBlock = WaitTimer; \
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WaitTimer->NextWaitBlock = WaitBlock; \
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Timer->Header.WaitListHead.Flink = &WaitTimer->WaitListEntry; \
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Timer->Header.WaitListHead.Blink = &WaitTimer->WaitListEntry; \
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} else { \
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WaitBlock->NextWaitBlock = WaitBlock; \
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} \
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Thread->Alertable = FALSE; \
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Thread->WaitMode = WaitMode; \
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Thread->WaitReason = WrQueue; \
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Thread->WaitListEntry.Flink = NULL; \
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StackSwappable = KiIsKernelStackSwappable(WaitMode, Thread); \
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Thread->WaitTime= KiQueryLowTickCount()
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PLIST_ENTRY
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KeRemoveQueue (
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IN PRKQUEUE Queue,
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IN KPROCESSOR_MODE WaitMode,
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IN PLARGE_INTEGER Timeout OPTIONAL
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)
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/*++
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Routine Description:
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This function removes the next entry from the Queue object entry
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list. If no list entry is available, then the calling thread is
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put in a wait state.
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N.B. The wait discipline for Queue object LIFO.
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Arguments:
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Queue - Supplies a pointer to a dispatcher object of type Queue.
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WaitMode - Supplies the processor mode in which the wait is to occur.
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Timeout - Supplies a pointer to an optional absolute of relative time over
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which the wait is to occur.
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Return Value:
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The address of the entry removed from the Queue object entry list or
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STATUS_TIMEOUT.
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N.B. These values can easily be distinguished by the fact that all
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addresses in kernel mode have the high order bit set.
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--*/
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{
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LARGE_INTEGER DueTime;
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PLIST_ENTRY Entry;
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LARGE_INTEGER NewTime;
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PRKQUEUE OldQueue;
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PLARGE_INTEGER OriginalTime;
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LOGICAL StackSwappable;
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PRKTHREAD Thread;
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PRKTIMER Timer;
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PRKWAIT_BLOCK WaitBlock;
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LONG_PTR WaitStatus;
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PRKWAIT_BLOCK WaitTimer;
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ASSERT_QUEUE(Queue);
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ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
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//
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// Set constant variables.
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//
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OriginalTime = Timeout;
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Thread = KeGetCurrentThread();
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Timer = &Thread->Timer;
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WaitBlock = &Thread->WaitBlock[0];
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WaitTimer = &Thread->WaitBlock[TIMER_WAIT_BLOCK];
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//
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// If the dispatcher database is already held, then initialize the thread
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// local variables. Otherwise, raise IRQL to DPC level, initialize the
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// thread local variables, and lock the dispatcher database.
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//
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if (Thread->WaitNext) {
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Thread->WaitNext = FALSE;
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InitializeRemoveQueue();
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} else {
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#if defined(NT_UP)
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Thread->WaitIrql = KeRaiseIrqlToDpcLevel();
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#else
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Thread->WaitIrql = KeRaiseIrqlToSynchLevel();
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#endif
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InitializeRemoveQueue();
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KiLockDispatcherDatabaseAtSynchLevel();
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}
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//
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// Check if the thread is currently processing a queue entry and whether
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// the new queue is the same as the old queue.
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//
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OldQueue = Thread->Queue;
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Thread->Queue = Queue;
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if (Queue != OldQueue) {
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//
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// If the thread was previously associated with a queue, then remove
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// the thread from the old queue object thread list and attempt to
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// activate another thread.
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//
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Entry = &Thread->QueueListEntry;
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if (OldQueue != NULL) {
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RemoveEntryList(Entry);
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KiActivateWaiterQueue(OldQueue);
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}
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//
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// Insert thread in the thread list of the new queue that the thread
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// will be associate with.
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//
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InsertTailList(&Queue->ThreadListHead, Entry);
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} else {
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//
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// The previous and current queue are the same queue - decrement the
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// current number of threads.
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//
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Queue->CurrentCount -= 1;
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}
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//
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//
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// Start of wait loop.
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//
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//
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// Note this loop is repeated if a kernel APC is delivered in the
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// middle of the wait or a kernel APC is pending on the first attempt
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// through the loop.
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//
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// If the Queue object entry list is not empty, then remove the next
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// entry from the Queue object entry list. Otherwise, wait for an entry
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// to be inserted in the queue.
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//
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do {
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//
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// Check if there is a queue entry available and the current
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// number of active threads is less than target maximum number
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// of threads.
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//
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Entry = Queue->EntryListHead.Flink;
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if ((Entry != &Queue->EntryListHead) &&
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(Queue->CurrentCount < Queue->MaximumCount)) {
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//
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// Decrement the number of entires in the Queue object entry list,
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// increment the number of active threads, remove the next entry
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// rom the list, and set the forward link to NULL.
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//
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Queue->Header.SignalState -= 1;
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Queue->CurrentCount += 1;
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if ((Entry->Flink == NULL) || (Entry->Blink == NULL)) {
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KeBugCheckEx(INVALID_WORK_QUEUE_ITEM,
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(ULONG_PTR)Entry,
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(ULONG_PTR)Queue,
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(ULONG_PTR)&ExWorkerQueue[0],
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(ULONG_PTR)((PWORK_QUEUE_ITEM)Entry)->WorkerRoutine);
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}
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RemoveEntryList(Entry);
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Entry->Flink = NULL;
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break;
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} else {
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//
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// Test to determine if a kernel APC is pending.
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//
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// If a kernel APC is pending and the previous IRQL was less than
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// APC_LEVEL, then a kernel APC was queued by another processor
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// just after IRQL was raised to DISPATCH_LEVEL, but before the
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// dispatcher database was locked.
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//
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// N.B. that this can only happen in a multiprocessor system.
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//
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if (Thread->ApcState.KernelApcPending && (Thread->WaitIrql < APC_LEVEL)) {
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//
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// Increment the current thread count, unlock the dispatcher
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// database, and lower IRQL to previous value. An APC interrupt
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// will immediately occur which will result in the delivery of
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// the kernel APC if possible.
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//
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Queue->CurrentCount += 1;
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KiUnlockDispatcherDatabase(Thread->WaitIrql);
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} else {
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//
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// Test if a user APC is pending.
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//
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if ((WaitMode != KernelMode) && (Thread->ApcState.UserApcPending)) {
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Entry = (PLIST_ENTRY)ULongToPtr(STATUS_USER_APC);
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Queue->CurrentCount += 1;
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break;
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}
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//
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// Check to determine if a timeout value is specified.
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//
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if (ARGUMENT_PRESENT(Timeout)) {
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//
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// If the timeout value is zero, then return immediately
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// without waiting.
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//
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if (!(Timeout->LowPart | Timeout->HighPart)) {
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Entry = (PLIST_ENTRY)ULongToPtr(STATUS_TIMEOUT);
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Queue->CurrentCount += 1;
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break;
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}
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//
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// Insert the timer in the timer tree.
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//
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// N.B. The constant fields of the timer wait block are
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// initialized when the thread is initialized. The
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// constant fields include the wait object, wait key,
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// wait type, and the wait list entry link pointers.
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//
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if (KiInsertTreeTimer(Timer, *Timeout) == FALSE) {
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Entry = (PLIST_ENTRY)ULongToPtr(STATUS_TIMEOUT);
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Queue->CurrentCount += 1;
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break;
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}
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DueTime.QuadPart = Timer->DueTime.QuadPart;
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}
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//
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// Insert wait block in object wait list.
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//
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InsertTailList(&Queue->Header.WaitListHead, &WaitBlock->WaitListEntry);
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//
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// Set the thread wait parameters, set the thread dispatcher
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// state to Waiting, and insert the thread in the wait list.
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//
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Thread->State = Waiting;
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if (StackSwappable != FALSE) {
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InsertTailList(&KiWaitListHead, &Thread->WaitListEntry);
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}
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//
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// Switch context to selected thread.
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//
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// Control is returned at the original IRQL.
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//
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ASSERT(Thread->WaitIrql <= DISPATCH_LEVEL);
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WaitStatus = KiSwapThread();
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//
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// If the thread was not awakened to deliver a kernel mode APC,
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// then return wait status.
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//
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Thread->WaitReason = 0;
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if (WaitStatus != STATUS_KERNEL_APC) {
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return (PLIST_ENTRY)WaitStatus;
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}
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if (ARGUMENT_PRESENT(Timeout)) {
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//
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// Reduce the amount of time remaining before timeout occurs.
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//
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Timeout = KiComputeWaitInterval(OriginalTime,
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&DueTime,
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&NewTime);
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}
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}
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//
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// Raise IRQL to DPC level, initialize the thread local variables,
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// lock the dispatcher database, and decrement the count of active
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// threads.
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//
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#if defined(NT_UP)
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Thread->WaitIrql = KeRaiseIrqlToDpcLevel();
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#else
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Thread->WaitIrql = KeRaiseIrqlToSynchLevel();
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#endif
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InitializeRemoveQueue();
|
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KiLockDispatcherDatabaseAtSynchLevel();
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Queue->CurrentCount -= 1;
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}
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} while (TRUE);
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//
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// Unlock the dispatcher database and return the list entry address or a
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// status of timeout.
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//
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KiUnlockDispatcherDatabase(Thread->WaitIrql);
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return Entry;
|
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}
|
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|
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PLIST_ENTRY
|
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KeRundownQueue (
|
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IN PRKQUEUE Queue
|
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)
|
|
|
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/*++
|
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|
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Routine Description:
|
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|
|
This function runs down the specified queue by removing the listhead
|
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from the queue list, removing any associated threads from the thread
|
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list, and returning the address of the first entry.
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|
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|
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Arguments:
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Queue - Supplies a pointer to a dispatcher object of type Queue.
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|
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Return Value:
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|
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If the queue list is not empty, then the address of the first entry in
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the queue is returned as the function value. Otherwise, a value of NULL
|
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is returned.
|
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--*/
|
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|
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{
|
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|
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PLIST_ENTRY Entry;
|
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PLIST_ENTRY FirstEntry;
|
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KIRQL OldIrql;
|
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PKTHREAD Thread;
|
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|
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ASSERT_QUEUE(Queue);
|
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ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
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|
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//
|
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// Raise IRQL to dispatch level and lock the dispatcher database.
|
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//
|
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|
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KiLockDispatcherDatabase(&OldIrql);
|
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|
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//
|
|
// Get the address of the first entry in the queue and check if the
|
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// list is empty or contains entries that should be flushed. If there
|
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// are no entries in the list, then set the return value to NULL.
|
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// Otherwise, set the return value to the address of the first list
|
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// entry and remove the listhead from the list.
|
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//
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|
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FirstEntry = Queue->EntryListHead.Flink;
|
|
if (FirstEntry == &Queue->EntryListHead) {
|
|
FirstEntry = NULL;
|
|
|
|
} else {
|
|
RemoveEntryList(&Queue->EntryListHead);
|
|
}
|
|
|
|
//
|
|
// Remove all associated threads from the thread list of the queue.
|
|
//
|
|
|
|
while (Queue->ThreadListHead.Flink != &Queue->ThreadListHead) {
|
|
Entry = Queue->ThreadListHead.Flink;
|
|
Thread = CONTAINING_RECORD(Entry, KTHREAD, QueueListEntry);
|
|
Thread->Queue = NULL;
|
|
RemoveEntryList(Entry);
|
|
}
|
|
|
|
//
|
|
// Unlock the dispatcher database, lower IRQL to its previous level,
|
|
// and return the function value.
|
|
//
|
|
|
|
KiUnlockDispatcherDatabase(OldIrql);
|
|
return FirstEntry;
|
|
}
|
|
|
|
VOID
|
|
FASTCALL
|
|
KiActivateWaiterQueue (
|
|
IN PRKQUEUE Queue
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function is called when the current thread is about to enter a
|
|
wait state and is currently processing a queue entry. The current
|
|
number of threads processign entries for the queue is decrement and
|
|
an attempt is made to activate another thread if the current count
|
|
is less than the maximum count, there is a waiting thread, and the
|
|
queue is not empty.
|
|
|
|
Arguments:
|
|
|
|
Queue - Supplies a pointer to a dispatcher object of type event.
|
|
|
|
Return Value:
|
|
|
|
None.
|
|
|
|
--*/
|
|
|
|
{
|
|
|
|
PRLIST_ENTRY Entry;
|
|
PRKTHREAD Thread;
|
|
PRKWAIT_BLOCK WaitBlock;
|
|
PRLIST_ENTRY WaitEntry;
|
|
|
|
//
|
|
// Decrement the current count of active threads and check if another
|
|
// thread can be activated. If the current number of active threads is
|
|
// less than the target maximum number of threads, there is a entry in
|
|
// in the queue, and a thread is waiting, then remove the entry from the
|
|
// queue, decrement the number of entries in the queue, and unwait the
|
|
// respectiive thread.
|
|
//
|
|
|
|
Queue->CurrentCount -= 1;
|
|
if (Queue->CurrentCount < Queue->MaximumCount) {
|
|
Entry = Queue->EntryListHead.Flink;
|
|
WaitEntry = Queue->Header.WaitListHead.Blink;
|
|
if ((Entry != &Queue->EntryListHead) &&
|
|
(WaitEntry != &Queue->Header.WaitListHead)) {
|
|
RemoveEntryList(Entry);
|
|
Entry->Flink = NULL;
|
|
Queue->Header.SignalState -= 1;
|
|
WaitBlock = CONTAINING_RECORD(WaitEntry, KWAIT_BLOCK, WaitListEntry);
|
|
Thread = WaitBlock->Thread;
|
|
KiUnwaitThread(Thread, (LONG_PTR)Entry, 0, NULL);
|
|
}
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
LONG
|
|
FASTCALL
|
|
KiInsertQueue (
|
|
IN PRKQUEUE Queue,
|
|
IN PLIST_ENTRY Entry,
|
|
IN BOOLEAN Head
|
|
)
|
|
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
This function inserts the specified entry in the queue object entry
|
|
list and attempts to satisfy the wait of a single waiter.
|
|
|
|
N.B. The wait discipline for Queue object is LIFO.
|
|
|
|
Arguments:
|
|
|
|
Queue - Supplies a pointer to a dispatcher object of type Queue.
|
|
|
|
Entry - Supplies a pointer to a list entry that is inserted in the
|
|
queue object entry list.
|
|
|
|
Head - Supplies a boolean value that determines whether the queue
|
|
entry is inserted at the head or tail of the queue if it can
|
|
not be immediately dispatched.
|
|
|
|
Return Value:
|
|
|
|
The previous signal state of the Queue object.
|
|
|
|
--*/
|
|
|
|
{
|
|
|
|
LONG OldState;
|
|
PRKTHREAD Thread;
|
|
PKTIMER Timer;
|
|
PKWAIT_BLOCK WaitBlock;
|
|
PLIST_ENTRY WaitEntry;
|
|
|
|
ASSERT_QUEUE(Queue);
|
|
|
|
//
|
|
// Capture the current signal state of queue object and check if there
|
|
// is a thread waiting on the queue object, the current number of active
|
|
// threads is less than the target number of threads, and the wait reason
|
|
// of the current thread is not queue wait or the wait queue is not the
|
|
// same queue as the insertion queue. If these conditions are satisfied,
|
|
// then satisfy the thread wait and pass the thread the address of the
|
|
// queue entry as the wait status. Otherwise, set the state of the queue
|
|
// object to signaled and insert the specified entry in the queue object
|
|
// entry list.
|
|
//
|
|
|
|
OldState = Queue->Header.SignalState;
|
|
Thread = KeGetCurrentThread();
|
|
WaitEntry = Queue->Header.WaitListHead.Blink;
|
|
if ((WaitEntry != &Queue->Header.WaitListHead) &&
|
|
(Queue->CurrentCount < Queue->MaximumCount) &&
|
|
((Thread->Queue != Queue) ||
|
|
(Thread->WaitReason != WrQueue))) {
|
|
|
|
//
|
|
// Remove the last wait block from the wait list and get the address
|
|
// of the waiting thread object.
|
|
//
|
|
|
|
RemoveEntryList(WaitEntry);
|
|
WaitBlock = CONTAINING_RECORD(WaitEntry, KWAIT_BLOCK, WaitListEntry);
|
|
Thread = WaitBlock->Thread;
|
|
|
|
//
|
|
// Set the wait completion status, remove the thread from its wait
|
|
// list, increment the number of active threads, and clear the wait
|
|
// reason.
|
|
//
|
|
|
|
Thread->WaitStatus = (LONG_PTR)Entry;
|
|
if (Thread->WaitListEntry.Flink != NULL) {
|
|
RemoveEntryList(&Thread->WaitListEntry);
|
|
}
|
|
|
|
Queue->CurrentCount += 1;
|
|
Thread->WaitReason = 0;
|
|
|
|
//
|
|
// If thread timer is still active, then cancel thread timer.
|
|
//
|
|
|
|
Timer = &Thread->Timer;
|
|
if (Timer->Header.Inserted == TRUE) {
|
|
KiRemoveTreeTimer(Timer);
|
|
}
|
|
|
|
//
|
|
// Ready the thread for execution.
|
|
//
|
|
|
|
KiReadyThread(Thread);
|
|
|
|
} else {
|
|
Queue->Header.SignalState += 1;
|
|
if (Head != FALSE) {
|
|
InsertHeadList(&Queue->EntryListHead, Entry);
|
|
|
|
} else {
|
|
InsertTailList(&Queue->EntryListHead, Entry);
|
|
}
|
|
}
|
|
|
|
return OldState;
|
|
}
|