Session Manager

Session Manager supports the ICCCM 1.1 WM_COMMAND and WM_SAVE_YOURSELF protocols, which permit:

Session Manager also provides an API to assist your application in saving and restoring its state at logout and login.

Session Manager is responsible for restarting applications at login. To do this, your application must tell Session Manager what command and command-line options are required to restart it. Use Xlib's XSetCommand() to set the WM_COMMAND property on your application's top-level window.

When Session Manager saves a session, such as at logout, your application might need to save some state information so it can be restored to a similar state. Session Manager can optionally notify your application that the session is being saved. Your application must inform Session Manager that it wants such notification. It does this by registering the WM_SAVE_YOURSELF protocol with its top-level window WM_PROTOCOLS property and setting up a callback procedure to handle the notification. To do this, use the XmAddWMProtocols() and XmAddWMProtocolsCallback() functions. Your application should not interact with the user in any way when processing the WM_SAVE_YOURSELF callback. (For example, it should not display a Save As dialog box.) It must set the WM_COMMAND property on its top-level window to notify Session Manager that it is done saving its state.

To enable your application to save state information, use the DtSessionSavePath() function to obtain the full path name of a file in which this information can be saved. At session restore time, use the DtSessionRestorePath() function to obtain the full path name of the state file your application uses to restore its state.

The Common Desktop Environment Workspace Manager is responsible for restoring an application's main top-level window (containing the WM_COMMAND) property to the proper workspace, geometry, and icon state. If an application has multiple top-level windows, it is the application's responsibility to restore the states of the other top-level windows. Refer to “Workspace Manager” for additional information.

Library and Header Files

The Desktop Services library, libDtSvc, provides access to many desktop APIs, including the one for session management. Include the Dt/Dt.h and Dt/Session.h header files to access the Session Manager API.

	NOTE: If your application uses any of the Session Manager APIs, it must first initialize the libDtSvc library by calling either DtInitialize() or DtAppInitialize(). Refer to the DtInitialize(3) or DtAppInitialize(3) man page for more information.

Demo Programs

You can find the Session Manager demos in /usr/dt/examples/dtsession. Read the README file for detailed information on the demos.

Related Documentation

For more information on Session Manager, see the relevant man pages and the Programmer's Guide.