12 <concept id="GUID-E6F08B67-8DBC-5896-946D-BD0D27F82FE2" xml:lang="en"><title>Views |
12 <concept id="GUID-E6F08B67-8DBC-5896-946D-BD0D27F82FE2" xml:lang="en"><title>Views |
13 of a Server Application System</title><prolog><metadata><keywords/></metadata></prolog><conbody> |
13 of a Server Application System</title><prolog><metadata><keywords/></metadata></prolog><conbody> |
14 <section id="GUID-AC0E13F3-5DFE-5060-BE09-B76A08632B5E"><title>Process view</title> <p>Client |
14 <section id="GUID-AC0E13F3-5DFE-5060-BE09-B76A08632B5E"><title>Process view</title> <p>Client |
15 objects, in the client, talk to server objects, in the server application. |
15 objects, in the client, talk to server objects, in the server application. |
16 The client and the server are in different processes. </p> <fig id="GUID-C5650791-6E61-5212-B563-42778AAEDE98"> |
16 The client and the server are in different processes. </p> <fig id="GUID-C5650791-6E61-5212-B563-42778AAEDE98"> |
17 <image href="GUID-08698D45-1F37-553A-9497-0081271535A1_d0e167629_href.png" placement="inline"/> |
17 <image href="GUID-08698D45-1F37-553A-9497-0081271535A1_d0e173722_href.png" placement="inline"/> |
18 </fig> </section> |
18 </fig> </section> |
19 <section id="GUID-1453B676-A271-5D89-80B4-88C8DBDEAF1C"><title>Service view</title> <p>The |
19 <section id="GUID-1453B676-A271-5D89-80B4-88C8DBDEAF1C"><title>Service view</title> <p>The |
20 diagram below shows the point of view of services which operate over the server |
20 diagram below shows the point of view of services which operate over the server |
21 application system. Services are things such as "printing", "send-as" and |
21 application system. Services are things such as "printing", "send-as" and |
22 "contacts selection", which offer useful functionality to applications. </p> <p>The |
22 "contacts selection", which offer useful functionality to applications. </p> <p>The |
23 server application framework provides generic service support over a client/server |
23 server application framework provides generic service support over a client/server |
24 link, upon which real services can be created. A service will typically provide |
24 link, upon which real services can be created. A service will typically provide |
25 a client-side interface that clients can use directly, and a server-side interface |
25 a client-side interface that clients can use directly, and a server-side interface |
26 that server applications have to implement. </p> <fig id="GUID-81435382-06BE-5057-A23D-EDDC829191E4"> |
26 that server applications have to implement. </p> <fig id="GUID-81435382-06BE-5057-A23D-EDDC829191E4"> |
27 <image href="GUID-CCC121FA-C180-5103-915D-583A0CE9FB45_d0e167645_href.png" placement="inline"/> |
27 <image href="GUID-CCC121FA-C180-5103-915D-583A0CE9FB45_d0e173738_href.png" placement="inline"/> |
28 </fig> </section> |
28 </fig> </section> |
29 <section id="GUID-A608EB50-672E-54B3-B438-BD42F7D3F191"><title>Symbian platform |
29 <section id="GUID-A608EB50-672E-54B3-B438-BD42F7D3F191"><title>Symbian platform |
30 component view</title> <p>The diagram below shows the Symbian platform components |
30 component view</title> <p>The diagram below shows the Symbian platform components |
31 involved in the server application support system. </p> <p>The core of the |
31 involved in the server application support system. </p> <p>The core of the |
32 server application framework support is in Apparc, built on the client/server |
32 server application framework support is in Apparc, built on the client/server |
47 of the server application framework can be used to start new application instances. |
47 of the server application framework can be used to start new application instances. |
48 Those based on Apparc's implementation must connect to a server application |
48 Those based on Apparc's implementation must connect to a server application |
49 which is already started. </p> <p>Applications will use the server application |
49 which is already started. </p> <p>Applications will use the server application |
50 framework appropriate for their platform. They may use whatever services are |
50 framework appropriate for their platform. They may use whatever services are |
51 available on that platform, subject to security restrictions. </p> <fig id="GUID-6D5FD60F-731C-57EB-9019-FEFD04EA29DC"> |
51 available on that platform, subject to security restrictions. </p> <fig id="GUID-6D5FD60F-731C-57EB-9019-FEFD04EA29DC"> |
52 <image href="GUID-D3F800F3-0818-5DF2-947C-AB8DE0C0053C_d0e167691_href.png" placement="inline"/> |
52 <image href="GUID-D3F800F3-0818-5DF2-947C-AB8DE0C0053C_d0e173784_href.png" placement="inline"/> |
53 </fig> </section> |
53 </fig> </section> |
54 <section><title>Client-server view</title> <p>The diagram below shows Apparc's |
54 <section><title>Client-server view</title> <p>The diagram below shows Apparc's |
55 implementation of the server application system from the client/server point |
55 implementation of the server application system from the client/server point |
56 of view. These are the points to note about this system: </p> <ul> |
56 of view. These are the points to note about this system: </p> <ul> |
57 <li id="GUID-1AAAFB86-9FF2-5E2E-90B6-675D38784A8E"><p>The basic client server |
57 <li id="GUID-1AAAFB86-9FF2-5E2E-90B6-675D38784A8E"><p>The basic client server |
76 sessions on client and server-side marshal parameters across the client server |
76 sessions on client and server-side marshal parameters across the client server |
77 link. Typically, the server-side will introduce a number of virtual functions |
77 link. Typically, the server-side will introduce a number of virtual functions |
78 to handle the client requests, which the server application must override |
78 to handle the client requests, which the server application must override |
79 and implement. </p> </li> |
79 and implement. </p> </li> |
80 </ul> <fig id="GUID-FBF5D23A-C44E-597D-8B85-9BAEACF55710"> |
80 </ul> <fig id="GUID-FBF5D23A-C44E-597D-8B85-9BAEACF55710"> |
81 <image href="GUID-866B69E6-8D4C-546F-B9C9-244AD8988DE5_d0e167767_href.png" placement="inline"/> |
81 <image href="GUID-866B69E6-8D4C-546F-B9C9-244AD8988DE5_d0e173860_href.png" placement="inline"/> |
82 </fig> </section> |
82 </fig> </section> |
83 <section id="GUID-4D0B549E-E11D-54E2-9D8C-90F04771FF48"><title>Security view </title> <p>This |
83 <section id="GUID-4D0B549E-E11D-54E2-9D8C-90F04771FF48"><title>Security view </title> <p>This |
84 section discusses security aspects of the server application support. Essentially, |
84 section discusses security aspects of the server application support. Essentially, |
85 both client and server need to protect themselves against malicious versions |
85 both client and server need to protect themselves against malicious versions |
86 of their counterpart that they may connect to. </p> <ol id="GUID-1E43D0D8-919E-5778-8C06-322C7049933A"> |
86 of their counterpart that they may connect to. </p> <ol id="GUID-1E43D0D8-919E-5778-8C06-322C7049933A"> |
104 <li id="GUID-D61DDBA1-9E29-53BC-9F3C-492A41ADEADF"><p>Service specific sub |
104 <li id="GUID-D61DDBA1-9E29-53BC-9F3C-492A41ADEADF"><p>Service specific sub |
105 sessions on the server-side should protect the server by checking the validity |
105 sessions on the server-side should protect the server by checking the validity |
106 of parameters received from the client. They should not assume that they are |
106 of parameters received from the client. They should not assume that they are |
107 talking to their equivalent class on the client-side. </p> </li> |
107 talking to their equivalent class on the client-side. </p> </li> |
108 </ol> <fig id="GUID-A040B1BF-AF99-5E41-B9F8-3245F54AD25C"> |
108 </ol> <fig id="GUID-A040B1BF-AF99-5E41-B9F8-3245F54AD25C"> |
109 <image href="GUID-8617B132-D8C8-5769-95B9-867815B45B18_d0e167817_href.png" placement="inline"/> |
109 <image href="GUID-8617B132-D8C8-5769-95B9-867815B45B18_d0e173910_href.png" placement="inline"/> |
110 </fig> </section> |
110 </fig> </section> |
111 <section id="GUID-8C154D80-591D-5834-93B0-A99E9EF4BCD2"><title>Sequence views</title> <p>The |
111 <section id="GUID-8C154D80-591D-5834-93B0-A99E9EF4BCD2"><title>Sequence views</title> <p>The |
112 following sections show sequence diagrams illustrating various dynamic relationships |
112 following sections show sequence diagrams illustrating various dynamic relationships |
113 between client and server application. </p> <p><b>Server application start</b> </p> <p>When |
113 between client and server application. </p> <p><b>Server application start</b> </p> <p>When |
114 a client wishes to establish a connection with a new server application, it |
114 a client wishes to establish a connection with a new server application, it |
127 tells the server a random number to use in the server name. The server name |
127 tells the server a random number to use in the server name. The server name |
128 is then generated from this random number and the UID of the server application. |
128 is then generated from this random number and the UID of the server application. |
129 Since both numbers are known to both parties, the combination can be checked |
129 Since both numbers are known to both parties, the combination can be checked |
130 for uniqueness and they can't be used to impersonate system servers. This |
130 for uniqueness and they can't be used to impersonate system servers. This |
131 name agreement system is therefore safe. </p> <fig id="GUID-DD480C95-45A1-5FE6-BDD6-A72E34BE0278"> |
131 name agreement system is therefore safe. </p> <fig id="GUID-DD480C95-45A1-5FE6-BDD6-A72E34BE0278"> |
132 <image href="GUID-5690EA18-106E-52E6-ABD3-4D5EE3CA8B23_d0e167865_href.png" placement="inline"/> |
132 <image href="GUID-5690EA18-106E-52E6-ABD3-4D5EE3CA8B23_d0e173958_href.png" placement="inline"/> |
133 </fig> <p><b>Service creation</b> </p> <p>Continuing from the previous diagram, |
133 </fig> <p><b>Service creation</b> </p> <p>Continuing from the previous diagram, |
134 this diagram shows the creation and use of a service specific sub-session |
134 this diagram shows the creation and use of a service specific sub-session |
135 between the client and server application. </p> <p>To use a service, the client |
135 between the client and server application. </p> <p>To use a service, the client |
136 must first create a service specific session. This happens during the call |
136 must first create a service specific session. This happens during the call |
137 to the <codeph>Connect…()</codeph> functions in <xref href="GUID-2E824A1A-078A-3D43-8B49-DF6328330B51.dita"><apiname>RApaAppServiceBase</apiname></xref> and <xref href="GUID-92F2DA99-0954-3399-9005-F3E817CB7E72.dita"><apiname>REikAppServiceBase</apiname></xref>. |
137 to the <codeph>Connect…()</codeph> functions in <xref href="GUID-2E824A1A-078A-3D43-8B49-DF6328330B51.dita"><apiname>RApaAppServiceBase</apiname></xref> and <xref href="GUID-92F2DA99-0954-3399-9005-F3E817CB7E72.dita"><apiname>REikAppServiceBase</apiname></xref>. |
140 no spare slots in the connect message, this UID is passed in the version field. |
140 no spare slots in the connect message, this UID is passed in the version field. |
141 The server application's override of the <codeph>CreateServiceL()</codeph> function |
141 The server application's override of the <codeph>CreateServiceL()</codeph> function |
142 is called passing in the UID of the requested service. The server application |
142 is called passing in the UID of the requested service. The server application |
143 can now instantiate it's implementation of the server-side objects for the |
143 can now instantiate it's implementation of the server-side objects for the |
144 service. </p> <fig id="GUID-7A6DB7F6-4CBC-5A69-A8E1-5BEF12911E20"> |
144 service. </p> <fig id="GUID-7A6DB7F6-4CBC-5A69-A8E1-5BEF12911E20"> |
145 <image href="GUID-84E742A8-2D24-55B8-A4DA-A67939A50754_d0e167895_href.png" placement="inline"/> |
145 <image href="GUID-84E742A8-2D24-55B8-A4DA-A67939A50754_d0e173988_href.png" placement="inline"/> |
146 </fig> <p><b>Service use</b> </p> <p>The diagram below shows the use of a |
146 </fig> <p><b>Service use</b> </p> <p>The diagram below shows the use of a |
147 service specific session between the client and server application. </p> <p>To |
147 service specific session between the client and server application. </p> <p>To |
148 use a service, the client-side implementation of the service sends service |
148 use a service, the client-side implementation of the service sends service |
149 specific messages to the server, which are passed to the service's interface |
149 specific messages to the server, which are passed to the service's interface |
150 in the server. This decodes the messages and calls virtual functions in the |
150 in the server. This decodes the messages and calls virtual functions in the |
151 server application's implementation of the service, to actually carry out |
151 server application's implementation of the service, to actually carry out |
152 the service. </p> <fig id="GUID-71C39EBC-EF06-5CA8-A7AC-ADD1BC8F562A"> |
152 the service. </p> <fig id="GUID-71C39EBC-EF06-5CA8-A7AC-ADD1BC8F562A"> |
153 <image href="GUID-68C4E5E5-65A2-51BC-B3DC-2B83D29212D4_d0e167911_href.png" placement="inline"/> |
153 <image href="GUID-68C4E5E5-65A2-51BC-B3DC-2B83D29212D4_d0e174004_href.png" placement="inline"/> |
154 </fig> <p><b>Server application lifetime monitoring</b> </p> <p>If the client |
154 </fig> <p><b>Server application lifetime monitoring</b> </p> <p>If the client |
155 application requires monitoring of the server application's lifetime, which |
155 application requires monitoring of the server application's lifetime, which |
156 it often will, it should implement the <xref href="GUID-1FE93B7E-FDA2-328A-A3A0-8C5351C1EF54.dita"><apiname>MApaServerAppExitObserver</apiname></xref> interface |
156 it often will, it should implement the <xref href="GUID-1FE93B7E-FDA2-328A-A3A0-8C5351C1EF54.dita"><apiname>MApaServerAppExitObserver</apiname></xref> interface |
157 and create a <xref href="GUID-DB7DF858-5380-368F-BDAD-F9B6CBA4A2CC.dita"><apiname>CApaServerAppExitMonitor</apiname></xref> to monitor a <xref href="GUID-2E824A1A-078A-3D43-8B49-DF6328330B51.dita"><apiname>RApaAppServiceBase</apiname></xref> derived |
157 and create a <xref href="GUID-DB7DF858-5380-368F-BDAD-F9B6CBA4A2CC.dita"><apiname>CApaServerAppExitMonitor</apiname></xref> to monitor a <xref href="GUID-2E824A1A-078A-3D43-8B49-DF6328330B51.dita"><apiname>RApaAppServiceBase</apiname></xref> derived |
158 connection to the server application. <codeph>CApaServerAppExitMonitor</codeph> opens |
158 connection to the server application. <codeph>CApaServerAppExitMonitor</codeph> opens |
159 a request for notification of exit to the server. When the server exits, this |
159 a request for notification of exit to the server. When the server exits, this |
160 notification will be completed. The <codeph>CApaServerAppExitMonitor</codeph> then |
160 notification will be completed. The <codeph>CApaServerAppExitMonitor</codeph> then |
161 runs and tells its observer that the server application has exited. </p> <fig id="GUID-5807A9C6-86FC-5779-BA9D-A490791E7EE5"> |
161 runs and tells its observer that the server application has exited. </p> <fig id="GUID-5807A9C6-86FC-5779-BA9D-A490791E7EE5"> |
162 <image href="GUID-3457B9BC-2F8F-55C1-9B5F-FA210D3439C6_d0e167942_href.png" placement="inline"/> |
162 <image href="GUID-3457B9BC-2F8F-55C1-9B5F-FA210D3439C6_d0e174035_href.png" placement="inline"/> |
163 </fig> </section> |
163 </fig> </section> |
164 <section><title>See also</title><p><xref href="GUID-940F3F6E-BA9C-5E19-9AC5-D848B5E175FB.dita">Application |
164 <section><title>See also</title><p><xref href="GUID-940F3F6E-BA9C-5E19-9AC5-D848B5E175FB.dita">Application |
165 Architecture Overview</xref></p></section> |
165 Architecture Overview</xref></p></section> |
166 </conbody></concept> |
166 </conbody></concept> |