Source code of Windows XP (NT5)
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/*++ BUILD Version: 0009 // Increment this if a change has global effects
Copyright (c) 1987-1993 Microsoft Corporation
Module Name:
buffring.h
Abstract:
This module defines the change buffering state requests related data structures in RDBSS.
Author:
Balan Sethu Raman (SethuR) 11-Nov-95 Created
Notes:
The buffering manager implementation consists of two primary data structures
(1) CHANGE_BUFFERING_STATE_REQUEST and (2) BUFFERING_MANAGER.
The BUFFERING_MANAGER tracks and initiates actions on all change buffering state
requests generated by the various mini redirectors as well as the RDBSS.
There are three lists associated with the buffering manager, i.e., the registration
list, the dispatcher list and the handler list.
The registration list contains all the requests initiated for which no processing
has been done. All DPC level indications merely register the indication in this
list. The access to this list is protected by a spin lock(RxStrucsupSpinLock).
The dispatcher list contains all the requests for which the lookup has not been
completed. This list is organized as a two tier list. The top level is based on
the NetRootKey. Each entry for a NetRootKey in this list has an associated cluster
of requests corresponding to the various SrvOpenKey's. This is the reason for
ghaving two LIST_ENTRY's in the request data structure as well. The
NetRootListEntry field is used for inter cluster threading and the listEntry
field is used for intra cluster threading.
The handler list consists of all the requests for which the lookup has been completed
and are awaiting processing.
The dispatcher list and the handler list access is protected by the buffering manager
mutex.
The three routines of interest to mini rdr writers are ...
1) RxIndicateChangeOfBufferingState -- for registering the request.
2) RxAssociateSrvOpenKey -- for associating a SRV_OPEN instance with the key.
Note that the key associations are irreverisble and will last the lifetime of the
associated SRV_OPEN.
Also note that 0 and 0xffffffff are not valid keys for SRV_OPEN. It has special
significance for the buffering manager.
--*/
#ifndef __BUFFRING_H__
#define __BUFFRING_H__
#define RX_REQUEST_PREPARED_FOR_HANDLING (0x10000000)
typedef struct _CHANGE_BUFFERING_STATE_REQUEST_ {
LIST_ENTRY ListEntry;
ULONG Flags;
PSRV_CALL pSrvCall;
PSRV_OPEN pSrvOpen;
PVOID SrvOpenKey;
PVOID pMRxContext;
} CHANGE_BUFFERING_STATE_REQUEST, *PCHANGE_BUFFERING_STATE_REQUEST;
typedef struct _RX_BUFFERING_MANAGER_ {
BOOLEAN fDispatcherActive;
BOOLEAN fNoWaitHandlerActive;
BOOLEAN fLastChanceHandlerActive;
UCHAR Pad;
KSPIN_LOCK SpinLock;
// This count is always incremented and never reset. This provides us with
// a quick mechanism to establish if a buffering state change request has
// been received for a given srvcall since a point in time.
LONG CumulativeNumberOfBufferingChangeRequests;
LONG NumberOfUnhandledRequests;
LONG NumberOfUndispatchedRequests;
LONG NumberOfOutstandingOpens;
LIST_ENTRY DispatcherList;
LIST_ENTRY HandlerList;
LIST_ENTRY LastChanceHandlerList;
RX_WORK_QUEUE_ITEM DispatcherWorkItem;
RX_WORK_QUEUE_ITEM HandlerWorkItem;
RX_WORK_QUEUE_ITEM LastChanceHandlerWorkItem;
FAST_MUTEX Mutex;
LIST_ENTRY SrvOpenLists[1];
} RX_BUFFERING_MANAGER, *PRX_BUFFERING_MANAGER;
#define RxAcquireBufferingManagerMutex(pBufferingManager) \
{ \
if (!ExTryToAcquireFastMutex(&(pBufferingManager)->Mutex)) { \
ExAcquireFastMutex(&(pBufferingManager)->Mutex); \
} \
}
#define RxReleaseBufferingManagerMutex(pBufferingManager) \
ExReleaseFastMutex(&(pBufferingManager)->Mutex)
extern VOID
RxpProcessChangeBufferingStateRequests(
PSRV_CALL pSrvCall,
BOOLEAN UpdateHandlerState);
extern VOID
RxProcessChangeBufferingStateRequests(
PSRV_CALL pSrvCall);
extern VOID
RxProcessFcbChangeBufferingStateRequest(
PFCB pFcb);
extern VOID
RxPurgeChangeBufferingStateRequestsForSrvOpen(
PSRV_OPEN pSrvOpen);
extern VOID
RxCompleteSrvOpenKeyAssociation(
IN OUT PSRV_OPEN pSrvOpen);
extern VOID
RxInitiateSrvOpenKeyAssociation(
IN OUT PSRV_OPEN pSrvOpen);
extern NTSTATUS
RxInitializeBufferingManager(
PSRV_CALL pSrvCall);
extern NTSTATUS
RxTearDownBufferingManager(
PSRV_CALL pSrvCall);
NTSTATUS
RxFlushFcbInSystemCache(
IN PFCB Fcb,
IN BOOLEAN SynchronizeWithLazyWriter
);
NTSTATUS
RxPurgeFcbInSystemCache(
IN PFCB Fcb,
IN PLARGE_INTEGER FileOffset OPTIONAL,
IN ULONG Length,
IN BOOLEAN UninitializeCacheMaps,
IN BOOLEAN FlushFile );
#endif __BUFFRING_H__