keyedevt.c File Reference

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

Include dependency graph for keyedevt.c:

Go to the source code of this file.

Classes
struct	_EX_KEYED_EVENT

Macros
#define	NDEBUG
#define	NUM_KEY_HASH_BUCKETS   23

Typedefs
typedef struct _EX_KEYED_EVENT	EX_KEYED_EVENT
typedef struct _EX_KEYED_EVENT *	PEX_KEYED_EVENT

Functions
	_IRQL_requires_max_ (APC_LEVEL)
VOID NTAPI	ExpInitializeKeyedEvent (_Out_ PEX_KEYED_EVENT KeyedEvent)
	_IRQL_requires_max_ (PASSIVE_LEVEL)

Variables
PEX_KEYED_EVENT	ExpCritSecOutOfMemoryEvent
POBJECT_TYPE	ExKeyedEventObjectType
static GENERIC_MAPPING	ExpKeyedEventMapping

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 12 of file keyedevt.c.

NUM_KEY_HASH_BUCKETS

#define NUM_KEY_HASH_BUCKETS   23

Definition at line 17 of file keyedevt.c.

Typedef Documentation

EX_KEYED_EVENT

typedef struct _EX_KEYED_EVENT EX_KEYED_EVENT

PEX_KEYED_EVENT

typedef struct _EX_KEYED_EVENT * PEX_KEYED_EVENT

Function Documentation

_IRQL_requires_max_() [1/2]

_IRQL_requires_max_

(

APC_LEVEL

)

Definition at line 44 of file keyedevt.c.

{
    OBJECT_TYPE_INITIALIZER ObjectTypeInitializer = {0};
    UNICODE_STRING TypeName = RTL_CONSTANT_STRING(L"KeyedEvent");
    UNICODE_STRING Name = RTL_CONSTANT_STRING(L"\\KernelObjects\\CritSecOutOfMemoryEvent");
    NTSTATUS Status;
    HANDLE EventHandle;
    OBJECT_ATTRIBUTES ObjectAttributes;
 
    /* Set up the object type initializer */
    ObjectTypeInitializer.Length = sizeof(ObjectTypeInitializer);
    ObjectTypeInitializer.GenericMapping = ExpKeyedEventMapping;
    ObjectTypeInitializer.PoolType = PagedPool;
    ObjectTypeInitializer.ValidAccessMask = KEYEDEVENT_ALL_ACCESS;
    ObjectTypeInitializer.UseDefaultObject = TRUE;
 
    /* Create the keyed event object type */
    Status = ObCreateObjectType(&TypeName,
                                &ObjectTypeInitializer,
                                NULL,
                                &ExKeyedEventObjectType);
    if (!NT_SUCCESS(Status)) return FALSE;
 
    /* Create the out of memory event for critical sections */
    InitializeObjectAttributes(&ObjectAttributes, &Name, OBJ_PERMANENT, NULL, NULL);
    Status = ZwCreateKeyedEvent(&EventHandle,
                                KEYEDEVENT_ALL_ACCESS,
                                &ObjectAttributes,
                                0);
    if (NT_SUCCESS(Status))
    {
        /* Take a reference so we can get rid of the handle */
        Status = ObReferenceObjectByHandle(EventHandle,
                                           KEYEDEVENT_ALL_ACCESS,
                                           ExKeyedEventObjectType,
                                           KernelMode,
                                           (PVOID*)&ExpCritSecOutOfMemoryEvent,
                                           NULL);
        ZwClose(EventHandle);
        return TRUE;
    }
 
    return FALSE;
}

_IRQL_requires_max_() [2/2]

_IRQL_requires_max_

(

PASSIVE_LEVEL

)

Definition at line 274 of file keyedevt.c.

{
    KPROCESSOR_MODE PreviousMode = KeGetPreviousMode();
    PEX_KEYED_EVENT KeyedEvent;
    HANDLE KeyedEventHandle;
    NTSTATUS Status;
 
    /* Check flags */
    if (Flags != 0)
    {
        /* We don't support any flags yet */
        return STATUS_INVALID_PARAMETER;
    }
 
    /* Create the object */
    Status = ObCreateObject(PreviousMode,
                            ExKeyedEventObjectType,
                            ObjectAttributes,
                            PreviousMode,
                            NULL,
                            sizeof(EX_KEYED_EVENT),
                            0,
                            0,
                            (PVOID*)&KeyedEvent);
 
    /* Check for success */
    if (!NT_SUCCESS(Status)) return Status;
 
    /* Initialize the keyed event */
    ExpInitializeKeyedEvent(KeyedEvent);
 
    /* Insert it */
    Status = ObInsertObject(KeyedEvent,
                            NULL,
                            AccessMask,
                            0,
                            NULL,
                            &KeyedEventHandle);
 
    /* Check for success (ObInsertObject dereferences!) */
    if (!NT_SUCCESS(Status)) return Status;
 
    if (PreviousMode != KernelMode)
    {
        /* Enter SEH for return */
        _SEH2_TRY
        {
            /* Return the handle to the caller */
            ProbeForWrite(OutHandle, sizeof(HANDLE), sizeof(HANDLE));
            *OutHandle = KeyedEventHandle;
        }
        _SEH2_EXCEPT(ExSystemExceptionFilter())
        {
            /* Get the exception code */
            Status = _SEH2_GetExceptionCode();
 
            /* Cleanup */
            ObCloseHandle(KeyedEventHandle, PreviousMode);
        }
        _SEH2_END;
    }
    else
    {
        *OutHandle = KeyedEventHandle;
    }
 
    /* Return Status */
    return Status;
}

ExpInitializeKeyedEvent()

VOID NTAPI ExpInitializeKeyedEvent

(

_Out_ PEX_KEYED_EVENT

KeyedEvent

)

Definition at line 95 of file keyedevt.c.

{
    ULONG i;
 
    /* Loop all hash buckets */
    for (i = 0; i < NUM_KEY_HASH_BUCKETS; i++)
    {
        /* Initialize the mutex and the wait lists */
        ExInitializePushLock(&KeyedEvent->HashTable[i].Lock);
        InitializeListHead(&KeyedEvent->HashTable[i].WaitListHead);
        InitializeListHead(&KeyedEvent->HashTable[i].ReleaseListHead);
    }
}

Referenced by _IRQL_requires_max_().

Variable Documentation

ExKeyedEventObjectType

POBJECT_TYPE ExKeyedEventObjectType

Definition at line 31 of file keyedevt.c.

Referenced by _IRQL_requires_max_().

ExpCritSecOutOfMemoryEvent

PEX_KEYED_EVENT ExpCritSecOutOfMemoryEvent

Definition at line 30 of file keyedevt.c.

Referenced by _IRQL_requires_max_().

ExpKeyedEventMapping

GENERIC_MAPPING ExpKeyedEventMapping

static

Initial value:

=
{
    STANDARD_RIGHTS_READ | KEYEDEVENT_WAIT,
    STANDARD_RIGHTS_WRITE | KEYEDEVENT_WAKE,
    STANDARD_RIGHTS_EXECUTE,
    KEYEDEVENT_ALL_ACCESS
}

Definition at line 34 of file keyedevt.c.

Referenced by _IRQL_requires_max_().