guildmaster

GNU Make jobserver protocol does not have provisions for implicitly returning job tokens when a client is terminated without a chance to write its tokens back. This poses a problem if you want to have just one jobserver FIFO per machine, intended to be shared by all build jobs.

guildmaster implements a FIFO-like jobserver node via CUSE (character device in userspace, a subsystem of FUSE) and keeps account of retrieved and returned tokens per each open file description. When the node is closed with non-zero balance (i.e. a client returned fewer tokens that it retrieved), it assumes that the client is about to terminate without fulfilling the protocol, and replenishes the token pool.

See Also

• steve (developed simultaneously)
• nixos-jobserver (prior art, FUSE-based)

Usage

guildmaster

guildmaster is a CUSE server providing /dev/guild FIFO-like jobserver node, intended to be run as a service. Can be run unprivileged, provided it has access to /dev/cuse, but /dev/guild is limited to root by default (udev rules can be used to grant wider permissions).

gm-run

gm-run <command> opens /dev/guild, retrieves one token, and runs <command> with --jobserver-auth=fifo:/dev/guild appended to MAKEFLAGS. Hence, it is a wrapper for jobserver-aware tools such as GNU Make and Ninja.