engevent.c File Reference

#include <win32k.h>
#include <ntddvdeo.h>
#include <debug.h>

Include dependency graph for engevent.c:

Go to the source code of this file.

Macros
#define	NDEBUG

Functions
_Must_inspect_result_	_Success_ (return !=FALSE)
BOOL APIENTRY	EngDeleteEvent (_In_ _Post_ptr_invalid_ PEVENT Event)
VOID APIENTRY	EngClearEvent (_In_ PEVENT Event)
LONG APIENTRY	EngSetEvent (_In_ PEVENT Event)
LONG APIENTRY	EngReadStateEvent (_In_ PEVENT Event)
PEVENT APIENTRY	EngMapEvent (_In_ HDEV hDev, _In_ HANDLE hUserObject, _Reserved_ PVOID Reserved1, _Reserved_ PVOID Reserved2, _Reserved_ PVOID Reserved3)
BOOL APIENTRY	EngUnmapEvent (_In_ PEVENT Event)
BOOL APIENTRY	EngWaitForSingleObject (_In_ PEVENT Event, _In_opt_ PLARGE_INTEGER TimeOut)

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 16 of file engevent.c.

Function Documentation

_Success_()

_Must_inspect_result_ _Success_

(

return !

= FALSE

)

Definition at line 22 of file engevent.c.

{
    BOOLEAN Result = TRUE;
    PENG_EVENT EngEvent;
 
    /* Allocate memory for the event structure */
    EngEvent = ExAllocatePoolWithTag(NonPagedPool,
                                     sizeof(ENG_EVENT) + sizeof(KEVENT),
                                     GDITAG_ENG_EVENT);
    if (EngEvent)
    {
        /* Set KEVENT pointer */
        EngEvent->fFlags = 0;
        EngEvent->pKEvent = EngEvent + 1;
 
        /* Initialize the kernel event */
        KeInitializeEvent(EngEvent->pKEvent,
                          SynchronizationEvent,
                          FALSE);
 
        /* Pass pointer to our structure to the caller */
        *ppEvent = EngEvent;
        DPRINT("EngCreateEvent() created %p\n", EngEvent);
    }
    else
    {
        /* Out of memory */
        DPRINT("EngCreateEvent() failed\n");
        Result = FALSE;
    }
 
    /* Return result */
    return Result;
}

EngClearEvent()

VOID APIENTRY EngClearEvent

(

_In_ PEVENT

Event

)

Definition at line 85 of file engevent.c.

{
    /* Clear the event */
    KeClearEvent(Event->pKEvent);
}

EngDeleteEvent()

BOOL APIENTRY EngDeleteEvent

(

_In_ _Post_ptr_invalid_ PEVENT

Event

)

Definition at line 63 of file engevent.c.

{
    DPRINT("EngDeleteEvent(%p)\n", Event);
 
    /* Check if it's a usermapped event */
    if (Event->fFlags & ENG_EVENT_USERMAPPED)
    {
        /* Disallow deletion of usermapped events */
        DPRINT1("Driver attempted to delete a usermapped event!\n");
        return FALSE;
    }
 
    /* Free the allocated memory */
    ExFreePoolWithTag(Event, GDITAG_ENG_EVENT);
 
    /* Return success */
    return TRUE;
}

EngMapEvent()

PEVENT APIENTRY EngMapEvent	(	_In_ HDEV	hDev,
		_In_ HANDLE	hUserObject,
		_Reserved_ PVOID	Reserved1,
		_Reserved_ PVOID	Reserved2,
		_Reserved_ PVOID	Reserved3
	)

Definition at line 114 of file engevent.c.

{
    PENG_EVENT EngEvent;
    PVOID pvEvent;
    NTSTATUS Status;
 
    /* Allocate memory for the event structure */
    EngEvent = ExAllocatePoolWithTag(NonPagedPool,
                                     sizeof(ENG_EVENT),
                                     GDITAG_ENG_EVENT);
    if (!EngEvent) return NULL;
 
    /* Zero it out */
    EngEvent->fFlags = 0;
    EngEvent->pKEvent = NULL;
 
    /* Create a handle, and have Ob fill out the pKEvent field */
    Status = ObReferenceObjectByHandle(hUserObject,
                                       EVENT_ALL_ACCESS,
                                       *ExEventObjectType,
                                       UserMode,
                                       &pvEvent,
                                       NULL);
    if (NT_SUCCESS(Status))
    {
        /* Pulse the event and set that it's mapped by user */
        KePulseEvent(pvEvent, EVENT_INCREMENT, FALSE);
        EngEvent->pKEvent = pvEvent;
        EngEvent->fFlags |= ENG_EVENT_USERMAPPED;
    }
    else
    {
        /* Free the allocation */
        ExFreePoolWithTag(EngEvent, GDITAG_ENG_EVENT);
        EngEvent = NULL;
    }
 
    /* Support legacy interface */
    if (Reserved1) *(PVOID*)Reserved1 = EngEvent;
    return EngEvent;
}

EngReadStateEvent()

LONG APIENTRY EngReadStateEvent

(

_In_ PEVENT

Event

)

Definition at line 105 of file engevent.c.

{
    /* Read the event state */
    return KeReadStateEvent(Event->pKEvent);
}

EngSetEvent()

LONG APIENTRY EngSetEvent

(

_In_ PEVENT

Event

)

Definition at line 94 of file engevent.c.

{
    /* Set the event */
    return KeSetEvent(Event->pKEvent,
                      IO_NO_INCREMENT,
                      FALSE);
}

EngUnmapEvent()

BOOL APIENTRY EngUnmapEvent

(

_In_ PEVENT

Event

)

Definition at line 163 of file engevent.c.

{
    /* Must be a usermapped event */
    if (!(Event->fFlags & ENG_EVENT_USERMAPPED)) return FALSE;
 
    /* Dereference the object, destroying it */
    ObDereferenceObject(Event->pKEvent);
 
    /* Free the Eng object */
    ExFreePoolWithTag(Event, GDITAG_ENG_EVENT);
    return TRUE;
}

EngWaitForSingleObject()

BOOL APIENTRY EngWaitForSingleObject	(	_In_ PEVENT	Event,
		_In_opt_ PLARGE_INTEGER	TimeOut
	)

Definition at line 179 of file engevent.c.

{
    NTSTATUS Status;
    DPRINT("EngWaitForSingleObject(%p %I64d)\n", Event, TimeOut->QuadPart);
 
    /* Validate parameters */
    if (!Event) return FALSE;
 
    /* Check if it's a usermapped event and fail in that case */
    if (Event->fFlags & ENG_EVENT_USERMAPPED)
    {
        /* Disallow deletion of usermapped events */
        DPRINT1("Driver attempted to wait on a usermapped event!\n");
        return FALSE;
    }
 
    /* Wait for the event */
    Status = KeWaitForSingleObject(Event->pKEvent,
                                   Executive,
                                   KernelMode,
                                   FALSE,
                                   TimeOut);
 
    /* Check if there is a failure or a timeout */
    return NT_SUCCESS(Status);
}