© 2008 by Wind River; made available under the EPL v1.0 | 19-Nov-2008 TCF The Target Communication Framework Michael Scharf, Wind River wiki.eclipse.org/DSDP/TM/TCF_FAQ

© 2008 by Wind River; made available under the EPL v1.0 | 19-Nov-2008

TCFThe Target Communication Framework

Michael Scharf, Wind Riverwiki.eclipse.org/DSDP/TM/TCF_FAQ

http://wiki.eclipse.org/DSDP/TM/TCF_FAQ

2 TCF: The Target Communication Framework | © 2008 Wind River; made available under the EPL v1.0 | Eclipse Summit Europe | Nov 2008

Credits

• Idea: Felix Burton (Wind River), Eugene Tarassov (Wind River)

• Original implementation Eugene Tarassov


Cross Development

• Communication with “target”:• Download (of executables)• Start/Stop Execution• Debugging• Tracing• Monitoring• …


Today: Incompatible Agent Solutions

UI

Target

Tool A Tool B Tool C Tool D

Agent A Agent B Agent C

Value Add B

Value Add CHost P1

P3

P2


Bad for the User

UI

Target



Value Add B

Value Add CHost P1

P3

P2

? ? ?


Bad Design!

UI

Target



Value Add B

Value Add CHost


Limited eco system

• Too many different tools agents and protocols


Design Goals of TCF

• Framework provides common infrastructure communication protocol Agent: “Service container” Proxying

• Tools can use services in uniform way• Service implementers can focus on functionality


TCF - Core Design Ideas

• Service knows best how to represent the system get information from there and data-drive layers above If not possible, put the knowledge in the lowest possible layer

and data drive the layers above

• Use the same protocol end-to-end allow value-adding servers to intercept select services

• Services as building blocks E.g. target agent, OCD, simulator Avoid tools specific agents

• Support high latency communication links


Service 4

Service 5

TCF: Common agent and protocol


TCF Agent

Value Add

UI

Target

Host

Service 1 Service 2 Service 3


Peer is a Communication endpoint

Service 4

Service 5


Value Add

UI

Target

Host


TCF Agent


Service

Service 4

Service 5


TCF Agent

Value Add

UI

Target

Host



Message Channel

Service 4

Service 5


TCF Agent

Value Add

UI

Target

Host


TCF Channel

TCF Channel


Channels and Messages

• Communication between peers use channels• Channels abstract/hide the transport layer

Currently TCP Possible: RS232, JTAG, USB etc

• Channels transmit Messages


TCF Communication Protocol

• Message A packet of data Transmitted over communication channel

• Multiple channels per peer

• Proxying/Tunneling Message forwarding “Decorator” can intercept communication “Value-add” services (e.g. debug info) No protocol conversion needed


The TCF Message Types

• Command (send) Request some action on remote peer

• Progress Long running commands may send “progress ticks”

• Result (reply) Remote peer sends one result for each command!

• Event Notify a change

• Flow control prevent congestion


Command

• Command is a message • Sent to remote peer• Remote peer must send one Result for each Command!


Result

• Result is a message Data, Errors

• Sent as a response to a command• Remote peer sends one Result per Command!


Commands are Asynchronous

• Sender of a command returns immediately Fast on high latency connections

• Sender receives results asynchronously


Event

• Event is a message • Notification about state changes


Message order guaranteed on channel

• Keep state of remote peer• Without message ordering no consistent state• Ordering per channel and direction

Command X=1Result

X=1Event

X=2Command X=3

Event X=4

Result X=3

Event X=5


Flow Control

• Prevent congestion


Service 4

Service 5

TCF: Layered View


TCF Agent

Value Add

UI

Target

Host



Communication Layers

Channel

Messages

Services

Transport Layer (e.g. TCP/IP)


Transport Layer: Byte Stream

Channel

Messages

?????????????????????????????????????????????

Services



Channel: Message Stream

Messages

??????????????????????????????????????????Channel

Services

??????????????????????????????????????????????Transport Layer (e.g. TCP/IP)


Messages: Command Result Event Flow

Messages

??????????????????????????????????????????

C 17 SysMonitor getChildren ??????

??????????????????????????????????????????????

Channel


Services


Message Type

Messages C 17 SysMonitor getChildren ??????

Message Type

??????????????????????????????????????????

??????????????????????????????????????????????

Channel


Services


Token


Token: Channel Unique

To identify Result

??????????????????????????????????????????

??????????????????????????????????????????????

Channel


Services


Service Id


Service id

??????????????????????????????????????????

??????????????????????????????????????????????

Channel


Services


Command Name


Command name

??????????????????????????????????????????

??????????????????????????????????????????????

Channel


Services


Arguments (byte array)


Arguments (byte array)

??????????????????????????????????????????

??????????????????????????????????????????????

Channel


Services


Argument Representation: e.g. JSON

Messages

C 17 SysMonitor getChildren [“p123”]

C 17 SysMonitor getChildren ??????

??????????????????????????????????????????

??????????????????????????????????????????????

Channel


Services

Marshalling: JSON


getChildren in JavaC 17 SysMonitor getChildren [“p123”]

R 17 [“p124”, “p125”]


The 5 TCF Messages

Command C • <token> • <service> • <command> • <arguments>

Progress P • <token> • <progress_data>Result R • <token> • <result_data>Event E • <service> • <event> • <event_data> Flow F • <traffic_congestion_level> •


Value-add

Service 4

Service 5


TCF Agent

Value Add

UI

Target

Host



Required service: Locator

• Used to discover peers• Peer lifecycle events• When connected peers can list its services


Auto Discovery

• Discovers Peers and Services

• Simplifies setup Client UI can easily find peers and discover services

• TCF comes with a simple UDP auto discovery Other mechanisms possible and optional


Prototype implementation

• Lightweight C-based agent Minimal agent has < 4000 lines of C code Minimal impact on the target

• Eclipse plug-ins Java TCF implementation to access service


TCF Services

• Run Control Service• Breakpoints Service• Memory Service• Registers Service

• Processes Service• Stack Trace Service• System Monitor Service • File System Service


Use Case: SimpleJtagDevice

• ProtocolTCP/IP

• ServicesService Manager (returns fixed list of services)Debug (run-control, breakpoint, memory access)Possibly Others (flash programming, download,

etc)• No Dynamic Addition or Removal of Services• No Multiplexing (single client)• No Forwarding• No Dynamic Discovery

41


Use Case: TestExceutionAgent

• ProtocolDepends on OS configuration and board

• ServicesService Manager (returns fixed list of services)Process launch and killStandard I/O redirectionFile system access

• No Dynamic Addition or Removal of Services• No Multiplexing (multiple clients)• No Forwarding• No Dynamic Discovery

42


Use Case: LinuxUserModeAgent

• Protocol Typically TCP/IP, but depends on OS configuration and

hardware• Services

Service Manager Debug (run-control, breakpoint, memory access) OS Awareness (process/thread list, CPU utilization, etc) Process launch and kill Standard I/O redirection File system access

• Possibly Dynamic Addition or Removal of Services• Possibly Multiplexing (multiple clients)• Possibly Forwarding• Possibly Dynamic Discovery

43


RSE sample

• Process service• File service


TCF Debugging example


Specification Status

• Review of current and specification of additional services in power.org and Eclipse


Links

• TCF source repository http://www.eclipse.org/dsdp/tm/development/tcf-anonymous.psf svn://dev.eclipse.org/svnroot/dsdp/org.eclipse.tm.tcf/trunk http://dev.eclipse.org/viewsvn/index.cgi/org.eclipse.tm.tcf

/?root=DSDP_SVN• FAQ

http://wiki.eclipse.org/DSDP/TM/TCF_FAQ Has links to all Documentation:

Getting Started (less than what we did) Protocol Specification (messages, events, JSON) Services description Agent description

47

http://www.eclipse.org/dsdp/tm/development/tcf-anonymous.psf

http://dev.eclipse.org/svnroot/dsdp/org.eclipse.tm.tcf/trunk








http://dev.eclipse.org/viewsvn/index.cgi/org.eclipse.tm.tcf/?root=DSDP_SVN







http://wiki.eclipse.org/DSDP/TM/TCF_FAQ


?



TCF vs. ECF

• TCF is a Protocol independent of API

• ECF is an API independent of Protocol


TCF and the OSI Layers

7 Application Layer

6 Presentation Layer

5 Session Layer

4 Transport Layer

3 Network Layer

2 Data Link Layer

1 Physical Layer

Channel + Messages

JSON

Services


TCF as Layer 3 and 4

7 Application Layer

6 Presentation Layer

5 Session Layer

4 Transport Layer

3 Network Layer

2 Data Link Layer

1 Physical Layer

JSON

Services

Channel + Messages



Use Case: SimpleJtagDevice

• Debug (run-control, breakpoint, memory register)• Possibly Others (flash programming, download, etc)


Use Case: TestExceutionAgent

• Process launch and kill• Standard I/O redirection• File system access


Use Case: LinuxUserModeAgent

• Debug (run-control, breakpoint, memory, register)• OS Awareness (process/thread list, CPU utilization,

etc potentially with value-add)• Process launch and kill• Standard I/O redirection• File system access• Monitoring (event-config, event-log)


Documents

© 2008 by Wind River; made available under the EPL v1.0 | 19-Nov-2008 TCF The Target Communication Framework Michael Scharf, Wind River wiki.eclipse.org/DSDP/TM/TCF_FAQ