COM

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COM

• ???
• http//www.icst.pku.edu.cn/CompCourse

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??

• COM??
• COM??
• COM??
• COM??
• COM??

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??COM??
COM??
COM??
IXxx p p-gt
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??COM??????
COM??
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COM?COM
COM
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COM????

• ?????????????Web??
• ??????
• ????????????????
• ???????
• ????????
• ?????????????
• ??????????????
• ?transaction?security?event?

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COM????

• ??????
• ?????????????????
• ?????????????????
• COM?COM??????
• ???COM runtime library
• ???MTS(Microsoft Transaction Server)
• ?????????
• ?????runtime??
• ???????????????(?????)
• COM??COM,??????????

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COM????????

• ??????????????????????,????????
• ?????????
• ???????????????
• ????COM????
• ?????????

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COMinterception??
???????????
Stub
RPC??
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COM????

• COM????
• COM Application ??????
• COM Components ??????
• COM Objects
• COM Application
• ????
• Server Application,DllHost.exe
• Library Application,???????,????
• ???????,???????
• COM Components?COM?????
• COM Objects?COM?????

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COM????

• Component Services snap-in

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????COM??

• ?????,??????COM?
• ????COM??
• COM runtime services???COM?????
• ?????????
• ??interceptor,???
• ??????????,??????
• COM????????????????????

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COM???????

• ??DLL?????
• ?????
• DllRegisterServer?DllUnregisterServer
• ???typelib
• typelib?????dll?,????????

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COM Catalog(COM??)

• COM??????????
• COM Registration Database
• ????????????COM Catalog
• COM Administration Library,????
• ????snap-in??????????????????
• ??????COMAdminCatalog??????????
• ProgIDCOMAdmin.COMAdminCatalog

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COMAdminCatalog????
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COMAdminCatalog??????

• Dim Catalog As new COMAdminCatalog
• Dim Applications As COMAdminCatalogCollection
• Dim Components As COMAdminCatalogCollection
• Dim AppObject As COMAdminCatalogObject
• ' get the Applications collection and populate it
• Set Applications Catalog.GetCollection("Applicat
  ions")
• Applications.Populate
• ' get the correct application, My Application
• For Each AppObject in Applicationss
• If AppObject.Name "My Application" Then Exit
  For
• Next
• ' get the Components collection for My
  Application
• Set Components Applications.GetCollection(
  "Components" , AppObject.Key )

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COM Context(COM??)

• ??????COM??
• COM?????,??context
• ??????????????
• ??????????????
• ????????????????
• ????????
• CoGetObjectContext
• GetObjectContext

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COM??(?)

• ????????
• IObjectContext
• IGetContextProperties
• IObjectContextInfo
• IContextState
• ISecurityCallContext
• ??????
• ??ASP??

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COM???

• ??????????????????
• Authentication ??(??)
• Authentication Level
• SSP/SSPI ????
• NTLM/Kerberos
• CoInitializeSecurity
• ????????

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COM???(??)

• ??(Authorization)
• Role-based
• ???????????
• ???????ISecurityCallContext?IObjectControl???
• IsSecurityEnabled
• IsCallerInRole
• ????ISecurityProperty

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COM???(??)

• ???????(identity)
• DCOM???????????? ????
• ???????????????
• ???????????
• trusted server model
• impersonation/dele-gation model

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COM????STA?MTA
??
STA
MTA
STA
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COM????TNA

• TNA(Thread neutral apartment)
• ?????,????,??????????
• TNA????
• ThreadingModelNeutral
• ?????????????????
• ???,??????????
• TNA?????Free?Both??
• STA????,?????UI???

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??(synchronization)

• ??serialization
• STA???????,MTA?TNA??????
• COM???activity-based synchronization
• activity???????????????
• ?????????
• ??activity????????????
• ???????????????

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Transaction(??)

• ???????????????
• ???????????????????
• ?????????????
• ??????,????????
• ????????????
• ??????????????,?????????????????????,??????????
  ??????????????

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???????

• DTC(Distributed Transaction Coordinator)
• ?????DTC??,DTC???????
• ?????
• ?????
• ????committing?aborting

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COM????

• COM runtime??????DTC
• ???DTC???
• IObjectContextSetComplete
• IObjectContextSetAbortComplete
• ???????

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Bank??
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?????
(1) ?????MoveMoney???Perform??
?? AccountA?? T1 (????)
(2) MoveMoney??AccountA??
?? MoveMoney?? T1 (?????)
?? AccountB?? T1 (??????)
(3) MoveMoney??AccountB??
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????
(2) Account????ADO???SQL Server
(1) ??Post
?? AccountA?? T1 (????)
?? MoveMoney?? T1 (?????)
(4) Account???? SQL Server??
?? AccountB?? T1 (??????)
DTC??
(5) SQL Server???????
SQL Server??? ?? ??
??ID ???? ?-100 T1 ?????? ?100 T1
(3) SQL Server??????T1?
SQL Server COM RM
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COM RM

• COM RM(Resource Manager)
• ?????????????????,?????????????
• ???????,RM??????????
• ????????,RM?????????
• ??????????MSMQ
• DTC???????
• ?????????,????
• ????RM?????????,??????
• ????DTC??RM????

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?????(ACID)

• Atomicity
• ??????????,?????
• Consistency
• ?????
• Isolation
• ??????????????
• Durability
• ???????????

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COM?????(?)
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COM?????(?)
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COM?????(?)
uuid(04CF0B76-1989-11D0-B917-0080C7394688),
helpstring("Account Class"), TRANSACTION_REQUIR
ED coclass CAccount default interface
IAccount uuid(04CF0B7B-1989-11D0-B917-0
080C7394688), helpstring("MoveMoney
Class"), TRANSACTION_REQUIRED coclass
CMoveMoney default interface
IMoveMoney
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????

• ???
• ??
• ??
• ????
• ??

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????????

• ?????
• transaction-vote bit???
• deactivate-on-return bit????,?????
• ???????????
• IObjectContext
• IContextState

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Transaction and Just-In-Time activation

• ????????JIT activation??

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JIT activation???

• ???? ????
• ????????
• ????????????????,??????????(???????)
• ????????
• ???????
• ???????
• ???????

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??????

• ???
• ??????IObjectControl??
• Activate
• Deactivate
• CanBePooled
• ?????????
• ???????STA
• ????
• ??????????

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???????(compensating resource manager)

• ????
• Undo,????????
• ???????
• RM????
• CRM
• ???COM?????CRM?????
• ??
• CRM Worker??????,???CRM Clerk
• CRM Clerk?????????,??DTC
• CRM compensator??????????
• DTC????????

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????(Queued Components)

• ???????,
• ???????
• ?????,????????????
• ????????????
• ???off-line??email,????outbox?,??on-line,????????
  
• ????????(????????),???????????????
• ????????????????????,????????????
• ????
• COM????????????????

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QC??
???
QC.Recorder
QC.Player
??
?? MSMQ
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MSMQ??
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QC???

• ??????
• ?????????Queue??,??????
• ?????????
• ???MSMQ??????
• ??QC??????MQ???
• ????????

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QC???
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QC?????
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????
Dim Ship As Object Set Ship GetObject("queue/ne
wVBShipProj.VBShip") Ship.CustomerID
1111 Ship.OrderID 2222 Ship.LineItem 12,
"Drummers drumming" Ship.LineItem 11, "Pipers
piping" Ship.LineItem 10, "Lords a
leaping" Ship.LineItem 9, "Ladies
dancing" Ship.LineItem 8, "Maids a
milking" Ship.LineItem 7, "Swans a
swimming" Ship.LineItem 6, "Geese a
laying" Ship.LineItem 5, "Gold rings" Ship.LineIte
m 4, "Calling birds" Ship.LineItem 3, "French
hens" Ship.LineItem 2, "Turtledoves" Ship.LineItem
1, "A partridge in a pear tree" Ship.Process
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QC???

• ????
• ????out?in,out?retval
• ????????????
• ??????????????????????????,??,?????????
• ?????????????,??????QC.Recorder???????
• ??????
• ????
• ??????????
• ????????QC
• ???????QC???????
• ????????????????????

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QC???(?)

• QC??????
• MSMQ??????RM
• ????QC??????
• ?????QC??????
• QC????
• ????????????
• ??????????

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QC?Moniker

• ??Moniker??QC??,??
• GetObject(queue/newVBShipProj.VBShip)
• ??????????,???????????
• queue????
• GetObject(queueComputerNameSomeMachine/newVBSh
  ipProj.VBShip)
• new????
• GetObject(newVBShipProj.VBShip)

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COM????

• ????????????
• publisher???
• subscriber???
• ????
• ???
• ????? tightly coupled event
• COM???loosely coupled event model

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COM??????
COM??
1 ??
2 ??
???
?????
3 ??
5 ??subscriber??
Publisher
Subscriber
????
4 ??
IFoo e1() e2() ...
IFoo e1() e2() ...
6 ????????subscriber
7 ????
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???????
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Subscriber????subscription
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Publisher????
' Create the event class object Dim foo As New
StockEventCls ' Call the event class object's
method that ' fires the StockPriceChanged
event. Private Sub Command1_Click() Call
foo.StockPriceChanged(Text1.Text,
CCur(Text2.Text)) End Sub ' Call the event class
object's method that ' fires the NewStockListed
event. Private Sub Command2_Click() Call
foo.NewStockListed(Text1.Text) End Sub
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Subscriber????
' The subscriber must implement the interface
on ' which it wants to receive calls from the
event object Implements StockEventCls ' Pop up
message box telling user of ' NewStockListed
event Private Sub StockEventCls_NewStockListed(By
Val Symbol As String) MsgBox "New Stock "
Symbol " has started trading", vbOKOnly,
_ "VB Event Subscriber" End Sub ' Pop up
message box telling user of ' StockPriceChanged
event Private Sub StockEventCls_StockPriceChanged
(ByVal Symbol As String, _ ByVal Price As
Currency) MsgBox "The market price of stock "
Symbol " is now _ Str(Price),
vbOKOnly, "VB Event Subscriber" End Sub
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subscription

• ????
• persistent
• transient

Set oCOMAdminCatalog CreateObject("COMAdmin.
COMAdminCatalog.1") 'Get the
TRANSIENTSUBSCRIPTIONS collection Set oTSCol
oCOMAdminCatalog.GetCollection("TransientSubscri
ptions") Set oSubscription oTSCol.Add
Set objvar objref oSubscription.Value("Subsc
riberInterface") objref oSubscription.Value(
"EventCLSID") clsid oSubscription.Value("Nam
e") "TransientSubscription"
oTSCol.SaveChanges
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????

• ????????
• ???QC??,???????????
• ??QC??,??????????????
• ????????????????,??????????
• ??????????
• ???????
• ????????

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???????
Publisher
Subscriber
????
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????????????

• ????????
• ??????
• ????????,??????,???????,?????????????????
• ??????
• ???COM????
• ?????????????

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COM????????????
1
Client
Source
Connection point
Sink object
2
Publisher
Event object
Subscriber
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COM?????

• IMDB(In-Memory Database)
• ????,????????
• CLB(Component Load Balancing)
• ???Application Center Server?
• Windows 2000 Advanced Server???
• ?clustering service????high-availability and
  scalability

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CLB?????
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COM???????

• COM?Active Directory Service
• COM?Security Sevices
• Kerberos?PKI
• COM?Data Access Services
• COM?DTC
• COM?MSMQ
• COM?Web Services

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COM??

• ??????,??????
• ??????????
• ??????,???????????ATL
• Attributed Programming
• ?????
• COM?????,??????????????,????????????????,????????
  ??????
• ?COM?????????????????

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Visual Studio .NET?COM???
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Attributed Programming
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????

• ?Understanding COM(????)
• ??????COM
• ?????Windows 2000?????
• ????MSDN-Library