event.c File Reference

#include <ntoskrnl.h>
#include <debug.h>

Include dependency graph for event.c:

Go to the source code of this file.

Macros
#define	NDEBUG

Functions
BOOLEAN NTAPI	ExpInitializeEventImplementation (VOID)
NTSTATUS NTAPI	NtClearEvent (IN HANDLE EventHandle)
NTSTATUS NTAPI	NtCreateEvent (OUT PHANDLE EventHandle, IN ACCESS_MASK DesiredAccess, IN POBJECT_ATTRIBUTES ObjectAttributes OPTIONAL, IN EVENT_TYPE EventType, IN BOOLEAN InitialState)
NTSTATUS NTAPI	NtOpenEvent (OUT PHANDLE EventHandle, IN ACCESS_MASK DesiredAccess, IN POBJECT_ATTRIBUTES ObjectAttributes)
NTSTATUS NTAPI	NtPulseEvent (IN HANDLE EventHandle, OUT PLONG PreviousState OPTIONAL)
NTSTATUS NTAPI	NtQueryEvent (IN HANDLE EventHandle, IN EVENT_INFORMATION_CLASS EventInformationClass, OUT PVOID EventInformation, IN ULONG EventInformationLength, OUT PULONG ReturnLength OPTIONAL)
NTSTATUS NTAPI	NtResetEvent (IN HANDLE EventHandle, OUT PLONG PreviousState OPTIONAL)
NTSTATUS NTAPI	NtSetEvent (IN HANDLE EventHandle, OUT PLONG PreviousState OPTIONAL)
NTSTATUS NTAPI	NtSetEventBoostPriority (IN HANDLE EventHandle)

Variables
POBJECT_TYPE	ExEventObjectType = NULL
GENERIC_MAPPING	ExpEventMapping
static const INFORMATION_CLASS_INFO	ExEventInfoClass []

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 13 of file event.c.

Function Documentation

ExpInitializeEventImplementation()

BOOLEAN NTAPI ExpInitializeEventImplementation

(

VOID

)

Definition at line 39 of file event.c.

{
    OBJECT_TYPE_INITIALIZER ObjectTypeInitializer;
    UNICODE_STRING Name;
    NTSTATUS Status;
    DPRINT("Creating Event Object Type\n");
 
    /* Create the Event Object Type */
    RtlZeroMemory(&ObjectTypeInitializer, sizeof(ObjectTypeInitializer));
    RtlInitUnicodeString(&Name, L"Event");
    ObjectTypeInitializer.Length = sizeof(ObjectTypeInitializer);
    ObjectTypeInitializer.DefaultNonPagedPoolCharge = sizeof(KEVENT);
    ObjectTypeInitializer.GenericMapping = ExpEventMapping;
    ObjectTypeInitializer.PoolType = NonPagedPool;
    ObjectTypeInitializer.ValidAccessMask = EVENT_ALL_ACCESS;
    ObjectTypeInitializer.InvalidAttributes = OBJ_OPENLINK;
    Status = ObCreateObjectType(&Name, &ObjectTypeInitializer, NULL, &ExEventObjectType);
    if (!NT_SUCCESS(Status)) return FALSE;
    return TRUE;
}

Referenced by ExpInitSystemPhase1().

NtClearEvent()

NTSTATUS NTAPI NtClearEvent

(

IN HANDLE

EventHandle

)

Definition at line 65 of file event.c.

{
    PKEVENT Event;
    NTSTATUS Status;
    PAGED_CODE();
 
    /* Reference the Object */
    Status = ObReferenceObjectByHandle(EventHandle,
                                       EVENT_MODIFY_STATE,
                                       ExEventObjectType,
                                       ExGetPreviousMode(),
                                       (PVOID*)&Event,
                                       NULL);
 
    /* Check for Success */
    if(NT_SUCCESS(Status))
    {
        /* Clear the Event and Dereference */
        KeClearEvent(Event);
        ObDereferenceObject(Event);
    }
 
    /* Return Status */
    return Status;
}

Referenced by ConDrvFlushConsoleInputBuffer(), ConDrvGetConsoleInput(), and ConSrvTermReadStream().

NtCreateEvent()

NTSTATUS NTAPI NtCreateEvent	(	OUT PHANDLE	EventHandle,
		IN ACCESS_MASK	DesiredAccess,
		IN POBJECT_ATTRIBUTES ObjectAttributes	OPTIONAL,
		IN EVENT_TYPE	EventType,
		IN BOOLEAN	InitialState
	)

Definition at line 96 of file event.c.

{
    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
    PKEVENT Event;
    HANDLE hEvent;
    NTSTATUS Status;
    PAGED_CODE();
    DPRINT("NtCreateEvent(0x%p, 0x%x, 0x%p)\n",
            EventHandle, DesiredAccess, ObjectAttributes);
 
    /* Check if we were called from user-mode */
    if (PreviousMode != KernelMode)
    {
        /* Enter SEH Block */
        _SEH2_TRY
        {
            /* Check handle pointer */
            ProbeForWriteHandle(EventHandle);
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            /* Return the exception code */
            _SEH2_YIELD(return _SEH2_GetExceptionCode());
        }
        _SEH2_END;
    }
 
    /* Create the Object */
    Status = ObCreateObject(PreviousMode,
                            ExEventObjectType,
                            ObjectAttributes,
                            PreviousMode,
                            NULL,
                            sizeof(KEVENT),
                            0,
                            0,
                            (PVOID*)&Event);
 
    /* Check for Success */
    if (NT_SUCCESS(Status))
    {
        /* Initialize the Event */
        KeInitializeEvent(Event,
                          EventType,
                          InitialState);
 
        /* Insert it */
        Status = ObInsertObject((PVOID)Event,
                                 NULL,
                                 DesiredAccess,
                                 0,
                                 NULL,
                                 &hEvent);
 
        /* Check for success */
        if (NT_SUCCESS(Status))
        {
            /* Enter SEH for return */
            _SEH2_TRY
            {
                /* Return the handle to the caller */
                *EventHandle = hEvent;
            }
            _SEH2_EXCEPT(ExSystemExceptionFilter())
            {
                /* Get the exception code */
                Status = _SEH2_GetExceptionCode();
            }
            _SEH2_END;
        }
    }
 
    /* Return Status */
    return Status;
}

Referenced by _At_(), AfdBind(), AfdConnect(), AfdGetInformation(), AfdSend(), AfdSendTo(), AfdSetInformation(), BaseSrvCreatePairWaitHandles(), ConDrvInitInputBuffer(), ConSrvInitConsole(), CreateContext(), CSR_SERVER_DLL_INIT(), CsrApiPortInitialize(), GetSocketInformation(), GuiInit(), GuiInitFrontEnd(), InitializeUserModePnpManager(), LsaConnectUntrusted(), main(), ReadBlock(), RtlCreateTimerQueue(), RtlDeleteTimer(), RtlDeregisterWaitEx(), RtlRegisterWait(), SetSocketInformation(), SmpInit(), SmpLoadSubSystem(), SockCreateOrReferenceAsyncThread(), StartAuthenticationPort(), Test_recv(), UnhandledExceptionFilter(), WSPAccept(), WSPBind(), WSPCloseSocket(), WSPConnect(), WSPEnumNetworkEvents(), WSPEventSelect(), WSPGetPeerName(), WSPGetSockName(), WSPListen(), WSPRecv(), WSPRecvFrom(), WSPSelect(), WSPSend(), WSPSendTo(), and WSPShutdown().

NtOpenEvent()

NTSTATUS NTAPI NtOpenEvent	(	OUT PHANDLE	EventHandle,
		IN ACCESS_MASK	DesiredAccess,
		IN POBJECT_ATTRIBUTES	ObjectAttributes
	)

Definition at line 181 of file event.c.

{
    HANDLE hEvent;
    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
    NTSTATUS Status;
    PAGED_CODE();
    DPRINT("NtOpenEvent(0x%p, 0x%x, 0x%p)\n",
            EventHandle, DesiredAccess, ObjectAttributes);
 
    /* Check if we were called from user-mode */
    if (PreviousMode != KernelMode)
    {
        /* Enter SEH Block */
        _SEH2_TRY
        {
            /* Check handle pointer */
            ProbeForWriteHandle(EventHandle);
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            /* Return the exception code */
            _SEH2_YIELD(return _SEH2_GetExceptionCode());
        }
        _SEH2_END;
    }
 
    /* Open the Object */
    Status = ObOpenObjectByName(ObjectAttributes,
                                ExEventObjectType,
                                PreviousMode,
                                NULL,
                                DesiredAccess,
                                NULL,
                                &hEvent);
 
    /* Check for success */
    if (NT_SUCCESS(Status))
    {
        /* Enter SEH for return */
        _SEH2_TRY
        {
            /* Return the handle to the caller */
            *EventHandle = hEvent;
        }
        _SEH2_EXCEPT(ExSystemExceptionFilter())
        {
            /* Get the exception code */
            Status = _SEH2_GetExceptionCode();
        }
        _SEH2_END;
    }
 
    /* Return status */
    return Status;
}

Referenced by CreateMemoryResourceNotification(), LsaConnectUntrusted(), LsapRmInitializeServer(), NtOpenObject(), and StartAuthenticationPort().

NtPulseEvent()

NTSTATUS NTAPI NtPulseEvent	(	IN HANDLE	EventHandle,
		OUT PLONG PreviousState	OPTIONAL
	)

Definition at line 244 of file event.c.

{
    PKEVENT Event;
    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
    NTSTATUS Status;
    PAGED_CODE();
    DPRINT("NtPulseEvent(EventHandle 0%p PreviousState 0%p)\n",
            EventHandle, PreviousState);
 
    /* Check if we were called from user-mode */
    if((PreviousState) && (PreviousMode != KernelMode))
    {
        /* Entry SEH Block */
        _SEH2_TRY
        {
            /* Make sure the state pointer is valid */
            ProbeForWriteLong(PreviousState);
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            /* Return the exception code */
            _SEH2_YIELD(return _SEH2_GetExceptionCode());
        }
        _SEH2_END;
    }
 
    /* Open the Object */
    Status = ObReferenceObjectByHandle(EventHandle,
                                       EVENT_MODIFY_STATE,
                                       ExEventObjectType,
                                       PreviousMode,
                                       (PVOID*)&Event,
                                       NULL);
 
    /* Check for success */
    if(NT_SUCCESS(Status))
    {
        /* Pulse the Event */
        LONG Prev = KePulseEvent(Event, EVENT_INCREMENT, FALSE);
        ObDereferenceObject(Event);
 
        /* Check if caller wants the old state back */
        if(PreviousState)
        {
            /* Entry SEH Block for return */
            _SEH2_TRY
            {
                /* Return previous state */
                *PreviousState = Prev;
            }
            _SEH2_EXCEPT(ExSystemExceptionFilter())
            {
                /* Get the exception code */
                Status = _SEH2_GetExceptionCode();
            }
            _SEH2_END;
        }
   }
 
   /* Return Status */
   return Status;
}

Referenced by PulseEvent().

NtQueryEvent()

NTSTATUS NTAPI NtQueryEvent	(	IN HANDLE	EventHandle,
		IN EVENT_INFORMATION_CLASS	EventInformationClass,
		OUT PVOID	EventInformation,
		IN ULONG	EventInformationLength,
		OUT PULONG ReturnLength	OPTIONAL
	)

Definition at line 313 of file event.c.

{
    PKEVENT Event;
    KPROCESSOR_MODE PreviousMode  = ExGetPreviousMode();
    NTSTATUS Status;
    PEVENT_BASIC_INFORMATION BasicInfo =
        (PEVENT_BASIC_INFORMATION)EventInformation;
    PAGED_CODE();
    DPRINT("NtQueryEvent(0x%p, 0x%x)\n", EventHandle, EventInformationClass);
 
    /* Check buffers and class validity */
    Status = DefaultQueryInfoBufferCheck(EventInformationClass,
                                         ExEventInfoClass,
                                         sizeof(ExEventInfoClass) /
                                         sizeof(ExEventInfoClass[0]),
                                         ICIF_PROBE_READ_WRITE,
                                         EventInformation,
                                         EventInformationLength,
                                         ReturnLength,
                                         NULL,
                                         PreviousMode);
    if(!NT_SUCCESS(Status))
    {
        /* Invalid buffers */
        DPRINT("NtQuerySemaphore() failed, Status: 0x%x\n", Status);
        return Status;
    }
 
    /* Get the Object */
    Status = ObReferenceObjectByHandle(EventHandle,
                                       EVENT_QUERY_STATE,
                                       ExEventObjectType,
                                       PreviousMode,
                                       (PVOID*)&Event,
                                       NULL);
 
    /* Check for success */
    if(NT_SUCCESS(Status))
    {
        /* Entry SEH Block */
        _SEH2_TRY
        {
            /* Return Event Type and State */
            BasicInfo->EventType = Event->Header.Type;
            BasicInfo->EventState = KeReadStateEvent(Event);
 
            /* Return length */
            if(ReturnLength) *ReturnLength = sizeof(EVENT_BASIC_INFORMATION);
        }
        _SEH2_EXCEPT(ExSystemExceptionFilter())
        {
            /* Get the exception code */
            Status = _SEH2_GetExceptionCode();
        }
        _SEH2_END;
 
        /* Dereference the Object */
        ObDereferenceObject(Event);
   }
 
   /* Return status */
   return Status;
}

Referenced by BaseCheckForVDM(), and QueryMemoryResourceNotification().

NtResetEvent()

NTSTATUS NTAPI NtResetEvent	(	IN HANDLE	EventHandle,
		OUT PLONG PreviousState	OPTIONAL
	)

Definition at line 386 of file event.c.

{
    PKEVENT Event;
    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
    NTSTATUS Status;
    PAGED_CODE();
    DPRINT("NtResetEvent(EventHandle 0%p PreviousState 0%p)\n",
            EventHandle, PreviousState);
 
    /* Check if we were called from user-mode */
    if ((PreviousState) && (PreviousMode != KernelMode))
    {
        /* Entry SEH Block */
        _SEH2_TRY
        {
            /* Make sure the state pointer is valid */
            ProbeForWriteLong(PreviousState);
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            /* Return the exception code */
            _SEH2_YIELD(return _SEH2_GetExceptionCode());
        }
        _SEH2_END;
    }
 
    /* Open the Object */
    Status = ObReferenceObjectByHandle(EventHandle,
                                       EVENT_MODIFY_STATE,
                                       ExEventObjectType,
                                       PreviousMode,
                                       (PVOID*)&Event,
                                       NULL);
 
    /* Check for success */
    if(NT_SUCCESS(Status))
    {
        /* Reset the Event */
        LONG Prev = KeResetEvent(Event);
        ObDereferenceObject(Event);
 
        /* Check if caller wants the old state back */
        if(PreviousState)
        {
            /* Entry SEH Block for return */
            _SEH2_TRY
            {
                /* Return previous state */
                *PreviousState = Prev;
            }
            _SEH2_EXCEPT(ExSystemExceptionFilter())
            {
                /* Get the exception code */
                Status = _SEH2_GetExceptionCode();
            }
            _SEH2_END;
        }
   }
 
   /* Return Status */
   return Status;
}

Referenced by CSR_API(), DeviceInstallThread(), and ResetEvent().

NtSetEvent()

NTSTATUS NTAPI NtSetEvent	(	IN HANDLE	EventHandle,
		OUT PLONG PreviousState	OPTIONAL
	)

Definition at line 455 of file event.c.

{
    PKEVENT Event;
    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
    NTSTATUS Status;
    PAGED_CODE();
    DPRINT("NtSetEvent(EventHandle 0%p PreviousState 0%p)\n",
           EventHandle, PreviousState);
 
    /* Check if we were called from user-mode */
    if ((PreviousState) && (PreviousMode != KernelMode))
    {
        /* Entry SEH Block */
        _SEH2_TRY
        {
            /* Make sure the state pointer is valid */
            ProbeForWriteLong(PreviousState);
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            /* Return the exception code */
            _SEH2_YIELD(return _SEH2_GetExceptionCode());
        }
        _SEH2_END;
    }
 
    /* Open the Object */
    Status = ObReferenceObjectByHandle(EventHandle,
                                       EVENT_MODIFY_STATE,
                                       ExEventObjectType,
                                       PreviousMode,
                                       (PVOID*)&Event,
                                       NULL);
    if (NT_SUCCESS(Status))
    {
        /* Set the Event */
        LONG Prev = KeSetEvent(Event, EVENT_INCREMENT, FALSE);
        ObDereferenceObject(Event);
 
        /* Check if caller wants the old state back */
        if (PreviousState)
        {
            /* Entry SEH Block for return */
            _SEH2_TRY
            {
                /* Return previous state */
                *PreviousState = Prev;
            }
            _SEH2_EXCEPT(ExSystemExceptionFilter())
            {
                Status = _SEH2_GetExceptionCode();
            }
            _SEH2_END;
        }
    }
 
    /* Return Status */
    return Status;
}

Referenced by AddInputEvents(), BaseSrvCleanupVDMResources(), ConSrvInitConsole(), CSR_API(), CsrApiRequestThread(), DeviceInstallThread(), GuiConsoleInputThread(), LsapNotifyPolicyChange(), LsapRmInitializeServer(), OnNcCreate(), PnpEventThread(), queue_add_timer(), queue_remove_timer(), RtlDeleteTimerQueueEx(), RtlDeregisterWaitEx(), RtlpUnWaitCriticalSection(), SetEvent(), SmpHandleConnectionRequest(), SmpInit(), SmpLoadSubSystem(), StartAuthenticationPort(), and Wait_thread_proc().

NtSetEventBoostPriority()

NTSTATUS NTAPI NtSetEventBoostPriority

(

IN HANDLE

EventHandle

)

Definition at line 521 of file event.c.

{
    PKEVENT Event;
    NTSTATUS Status;
    PAGED_CODE();
 
    /* Open the Object */
    Status = ObReferenceObjectByHandle(EventHandle,
                                       EVENT_MODIFY_STATE,
                                       ExEventObjectType,
                                       ExGetPreviousMode(),
                                       (PVOID*)&Event,
                                       NULL);
    if (NT_SUCCESS(Status))
    {
        /* Set the Event */
        KeSetEventBoostPriority(Event, NULL);
        ObDereferenceObject(Event);
    }
 
    /* Return Status */
    return Status;
}

Variable Documentation

ExEventInfoClass

const INFORMATION_CLASS_INFO ExEventInfoClass[]

static

Initial value:

=
{
    
    IQS_SAME(EVENT_BASIC_INFORMATION, ULONG, ICIF_QUERY),
}

Definition at line 28 of file event.c.

Referenced by NtQueryEvent().

ExEventObjectType

POBJECT_TYPE ExEventObjectType = NULL

Definition at line 18 of file event.c.

Referenced by AfdEnumEvents(), AfdEventSelect(), EngMapEvent(), ExpInitializeEventImplementation(), InitThreadCallback(), IopCreateEvent(), IopDeviceFsIoControl(), KspEnableEvent(), MiCreateMemoryEvent(), NtClearEvent(), NtCreateEvent(), NtLockFile(), NtNotifyChangeDirectoryFile(), NtOpenEvent(), NtPulseEvent(), NtQueryDirectoryFile(), NtQueryEvent(), NtReadFile(), NtResetEvent(), NtSetEvent(), NtSetEventBoostPriority(), NtSignalAndWaitForSingleObject(), NtWriteFile(), TestObjectTypes(), and WdmAudControlOpenMixer().

ExpEventMapping

GENERIC_MAPPING ExpEventMapping

Initial value:

=
{
    STANDARD_RIGHTS_READ | EVENT_QUERY_STATE,
    STANDARD_RIGHTS_WRITE | EVENT_MODIFY_STATE,
    STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE,
    EVENT_ALL_ACCESS
}

Definition at line 20 of file event.c.

Referenced by ExpInitializeEventImplementation().