DocsAt connection close, all event selections made by the client are discarded. If the client has the pointer actively grabbed, an UngrabPointer is performed. If the client has the keyboard actively grabbed, an UngrabKeyboard is performed. All passive grabs by the client are released. If the client has the server grabbed, an UngrabServer is performed. All selections (see SetSelectionOwner request) owned by the client are disowned. If close-down mode (see SetCloseDownMode request) is RetainPermanent or RetainTemporary, then all resources (including colormap entries) allocated by the client are marked as permanent or temporary, respectively (but this does not prevent other clients from explicitly destroying them). If the mode is Destroy, all of the client's resources are destroyed.
When a client's resources are destroyed, for each window in the client's save-set, if the window is an inferior of a window created by the client, the save-set window is reparented to the closest ancestor such that the save-set window is not an inferior of a window created by the client. If the save-set window is unmapped, a MapWindow request is performed on it (even if it was not an inferior of a window created by the client). The reparenting leaves unchanged the absolute coordinates (with respect to the root window) of the upper-left outer corner of the save-set window. After save-set processing, all windows created by the client are destroyed. For each nonwindow resource created by the client, the appropriate Free request is performed. All colors and colormap entries allocated by the client are freed.
A server goes through a cycle of having no connections and having some connections. At every transition to the state of having no connections as a result of a connection closing with a Destroy close-down mode, the server resets its state as if it had just been started. This starts by destroying all lingering resources from clients that have terminated in RetainPermanent or RetainTemporary mode. It additionally includes deleting all but the predefined atom identifiers, deleting all properties on all root windows, resetting all device maps and attributes (key click, bell volume, acceleration), resetting the access control list, restoring the standard root tiles and cursors, restoring the default font path, and restoring the input focus to state PointerRoot.
Note that closing a connection with a close-down mode of RetainPermanent or RetainTemporary will not cause the server to reset.