XLIB Programming Manual, Rel. 5, Third Edition

15.6 Connection Close Operations

When the connection between the X server and a client is closed, either by a call to XCloseDisplay() or by an exiting process, the X server performs these automatic operations:

• Disowns all selections made by the program.

• Releases all passive grabs made by the program.

• Performs an XUngrabPointer() and XUngrabKeyboard() if the client application had actively grabbed the pointer or the keyboard.

• Performs an XUngrabServer() if the client had grabbed the server.

• Marks all resources (including colormap entries) allocated by the client application as permanent or temporary, according to whether the close down mode is RetainPermanent or RetainTemporary (see 15.5 Close Down Mode).

The X server performs these operations when the close down mode is DestroyAll:

• The save-set is a list of other client’s windows, referred to as save-set windows (see 16.4 Window Save-set for a complete description of save-sets). If any window in the client’s save-set is an inferior of a window created by the client, the X server reparents the save-set window to the closest ancestor so that the save-set window is not an inferior of a window created by the client.

• Performs an XMapWindow() request on the save-set window if the save-set window is unmapped. The X server does this even if the save-set window was not an inferior of a window created by the client.

• Destroys all windows created by the client, after examining each window in the client’s save-set.

• Performs the appropriate free request ...