Shared memory support

Shared memory is needed by the MIT-SHM and XFree86-BigFont extensions, which may provide better performance for local applications which use large images or fonts and are written to use those extensions.

In Cygwin, XSI shared memory is provided by the cygserver Windows service. To install cygserver, install it using the setup program, run the cygserver-config script to install the service, and then reboot or use cygrunsrv -S cygserver to start the service.

Note: This note is applicable to Cygwin 1.5 only. Cygwin 1.7 automatically enables shared memory if the cygserver Windows service is running.

Shared memory will only be used if the CYGWIN environment variable contains the server keyword.

For example, starting X with

CYGWIN=server X
or setting the CYGWIN environment variable in the Windows control panel to contain server will enable shared memory support if the cygserver service is running.