Debugging traditional Synergy with Visual Studio

This topic includes the following sections:

 

With Synergy DBL Integration for Visual Studio (SDI), you can use Visual Studio to debug traditional Synergy programs. You'll use Visual Studio commands to start and control debugging (Start Debugging, Step Into, Break All, Attach to Process, Stop Debugging, etc.), and you can use some standard traditional Synergy debugger commands.

You can also remotely debug a Synergy program — i.e., debug a Synergy program on a different machine (Windows, UNIX, or OpenVMS) — even if you have no Visual Studio project for that program. See Remote debugging below.

Note

The latest version of Synergy/DE (with the most recent hotfix that includes debugger fixes) provides the best traditional Synergy debugging experience in Visual Studio, even if you only target older versions of the Synergy runtime. Traditional Synergy debugging in Visual Studio relies on runtime features distributed with Synergy/DE.

Before debugging, build projects in debug mode. (The debugger can step into a routine only if the project is built in debug mode.) Then, while your project is open in Visual Studio, select a Visual Studio debugging command, such as Debug > Start Debugging from the Visual Studio menu. See Visual Studio documentation for more information on debugging, and note the following:

!DEPOSIT var_name=value

See Standard traditional Synergy debugger commands below.

Standard traditional Synergy debugger commands

You can use one of the following standard traditional Synergy debugger commands by entering it in the Immediate window when the debugger has paused for a breakpoint: DEPOSIT, SET TRAP, SET UNINITIALIZED, SET WATCH, or a SHOW command.

1. Set at least one Visual Studio debugger breakpoint at a location in code that's executed before you want the standard traditional Synergy debugger command to take effect.
2. Start a debugging session for your traditional Synergy program.
3. When the debugger breaks on a Visual Studio breakpoint, open the Immediate window and type an exclamation point (!) followed by the command. Then press ENTER. For example:

1. Entering a traditional Synergy debugger command in the Immediate window.

Entering a traditional Synergy debugger command in the Immediate window

Be sure to use the exclamation point. If you enter one of these commands without the exclamation point, the debugger will interpret it as a variable, which will cause errors.

4. Continue with the debugging session (e.g., press F5 or select Debug > Continue).

If you enter a standard traditional Synergy command in this window before starting a debugging session, the traditional Synergy debugger will start in an unusable state.

Breaking and breakpoints

The debugger automatically breaks if it encounters an uncaught error or an unhandled exception (postmortem debugging), allowing the program to display an error message in a pop-up window. You can set an option that causes the debugger to break also on caught errors and exceptions, and you can instruct the debugger to ignore some caught errors and exceptions by adding them to a list. See Debug page, Project Designer for more information.

!SET WATCH var_name

See Standard traditional Synergy debugger commands above for more information.

Traditional Synergy debugging for Linux and OpenVMS

For Linux, you can develop and build code with Visual Studio (see Developing a traditional Synergy application), but because of path differences between Windows and Linux, you will not be able to run and debug your program on Windows. Instead, set the output path (on the Build page of Project Designer) to a network share on a Linux machine, build the program, run it on the Linux machine, and then use remote debugging to debug the application from Visual Studio or use standard traditional Synergy debugging on the Linux machine.

For OpenVMS, you can code and build with Visual Studio on Windows, and you may be able to run on Windows (see Developing a traditional Synergy application), which means you may be able to do some debugging on Windows from Visual Studio. For full debugging, run the application on an OpenVMS machine and then use remote debugging to debug the application from Visual Studio or use standard traditional Synergy debugging on the OpenVMS machine.

Remote debugging

You can use the Visual Studio Remote Debugger to debug a traditional Synergy program running on Windows, UNIX, or OpenVMS. (This includes xfServerPlus server code when xfServerPlus is on a Windows, UNIX, or OpenVMS machine.) You don’t need to have a Visual Studio project for the program, but the program must be built in debug mode, SDI must be installed, you’ll need the source file (.dbl) with the code you want to step through, and an open port must be available for Telnet access. The following is a summary of the process. See Remotely debugging a traditional Synergy program below for details.

1. Open the source file and set breakpoints in Visual Studio.
2. Start the program on the remote machine. Use the ‑dv option to enable Visual Studio debugging and the ‑rd option to specify a remote debugging port. For example:
dbr -dv -rd 1965 my_program
3. In Visual Studio, select Debug > Attach to Process.
4. In the Attach to Process dialog, set the Transport option to "Synergy (telnet based)", enter the IP address or machine name in the "Specify IP address and port" field, and click ENTER.
5. In the Available Processes area of the dialog, select "dbr base". Then click the Attach button.

Note the following:

Remotely debugging a traditional Synergy program

1. In Visual Studio, open the .dbl file(s) that you want to step through, and set breakpoints.

For OpenVMS, the remote debugger ignores paths. The file you open in Visual Studio determines which program on the OpenVMS machine will be debugged. This may not work if more than one file has the same name.

For an xfServerPlus program, this will be the .dbl file (or files) with the routines that are accessed via xfServerPlus.

2. On the remote machine, start the traditional Synergy program you want to debug remotely.

For client or stand-alone programs, use dbr with the ‑dv and ‑rd options. (The ‑dv option enables Visual Studio debugging mode, and the ‑rd option specifies the remote debugging port.) For example:

dbr -dv -rd 1965 my_program

For OpenVMS, use the RUN command. For example:

$ RUN MY_PROGRAM

For xfServerPlus server code, restart the xfServerPlus session with remote debugging enabled (or you can start a completely new session on a different port if desired). Then run the xfNetLink client application so that a connection is made to xfServerPlus and the xfServerPlus code is invoked. See Restarting xfServerPlus with remote debugging below.

Note

If there is a firewall between xfServerPlus and the Windows machine with Visual Studio (which uses a Telnet client for remote debugging), the firewall must be configured to allow Telnet access on the debug port number. (Most firewalls are configured to prohibit Telnet access.) If you do not have authorization to reconfigure the firewall, you can either run Visual Studio on a machine within the firewall or use another debug method.

If the xfNetLink Java or .NET client uses pooling, you should set both the minimum and maximum pool size to 1 before using Visual Studio remote debugging.

3. Open the Attach to Process dialog in Visual Studio (Debug > Attach to Process).
4. In the Attach to Process dialog, select "Synergy (telnet based)" from the Transport drop-down list.

2. Selecting the “Synergy (telnet based)” option in the Attach to Process dialog.

Selecting the Synergy (telnet based) option in the Attach to Process dialog

5. In the "Specify IP address and port" field, enter the IP address or machine name and the port number separated by a colon (for example, 172.16.254.1:1965 or localhost:1965) and click enter. (Do not click the Find button.) For xfServerPlus server code, make sure the port you specify is the debug port number specified for remote debugging in step 2. (For the example illustrated in figure 4 below, the port number would be 9999.)
6. Make sure the “dbr base” process is selected in the Available Processes section of the dialog, and then click Attach. Note the following for xfServerPlus:

Once connected, the remote debug session works just like any other Visual Studio debug session for traditional Synergy. If you get an error, check the time-out setting and make sure it is long enough for you to complete step 3 through step 6.

If paths on the remote machine don't match specified paths, Visual Studio dialogs will open as you debug, prompting you for paths.

When you are finished debugging an OpenVMS program, unset the DBG_RMT logical.

When you are through debugging an xfServerPlus program, run the Synergy Configuration Program (or restart rsynd without the ‑rd option) to turn off remote debugging. If you leave remote debugging enabled, the server will always wait for the specified time-out before continuing with the application. Note the following for xfServerPlus:

Restarting xfServerPlus with remote debugging

To restart the xfServerPlus session with remote debugging enabled, do one of the following:

On Windows,

1. Run the Synergy Configuration Program.
2. On the xfServer/xfServerPlus tab, select the desired xfServerPlus service and click the Modify Service button.
3. Select "Enable remote debugging", specify a debug port number for the server to listen on for the Telnet client (which is the Visual Studio remote debugger), and indicate a time-out value, if desired.

The default time-out is 100 seconds. This determines how long the server will wait for a Telnet connection after the xfNetLink-xfServerPlus connection has been established. This time-out should always be less than the connect time-out set on the client (which defaults to 120 seconds), but it needs to be long enough for you to attach to the xfServerPlus process (step 3 through step 6 above) after the client connects to xfServerPlus.

4. OK the modify dialog, and then click the Apply button on the xfServer/xfServerPlus tab to restart xfServerPlus with debug enabled.

4. Setting remote debugging options in the xfServerPlus Information window.

Setting remote debugging options in the xfServerPlusinformation window

For details on using the Synergy Configuration Program, refer to the Synergy Configuration Program online help.

Note

When remotely debugging xfServerPlus server code on Windows, xfpl.dbr uses the regular runtime (dbr) instead of the non-interactive runtime (dbs). This means that your environment may change, because dbr always reads the synergy.ini file, whereas dbs reads it only when SFWINIPATH is set. We recommend that you use SFWINIPATH to point to the location of your synergy.ini file and thereby avoid potential problems. For information on dbs, see Non‑interactive runtimes.

On UNIX,

1. Stop the current xfServerPlus service, and then restart it with the ‑rd option:
rsynd -rd debug_port[:timeout] -w -u xfspAcct

where debug_port is the port number that the xfServerPlus machine should listen on for the Telnet client, and timeout is the number of seconds that the server should wait for a Telnet connection after the xfNetLink-xfServerPlus connection has been made.

The default time-out is 100 seconds. This should always be less than the connect time-out set on the client (which defaults to 120 seconds), but it needs to be long enough for you to attach to the xfServerPlus process (step 3 through step 6 above) after the client connects to xfServerPlus. (For more information about starting xfServerPlus, see Running xfServerPlus on UNIX. For complete rsynd syntax, see rsynd program.)