Consh is a set of programs that can turn one or more UNIX hosts on a trusted LAN into a singular Bourne shell multi-computer on which shell scripts are run concurrently. The service abstracts hosts into what appears to be shell process with a fixed number of threads or workers, to which work may be assigned and results received concurrently. It includes utilities that assign commands to workers in parallel and a command that initiates distributed barriers between workers for synchronization purposes. Environment variables can be set on a per-host basis to implement locking mechanisms like semaphores or ticket algorithms. Daemons can delegate work to one another as needed.
Safelock is a file-based locking primitive that provides mutual exclusion between unrelated processes and threads. It offers advantages over POSIX and BSD file locks such as: compatibility with multi-threaded applications, support for lock attempt timeouts, detection of crashed lock holders, and detailed lock status (PID, lock age, custom data).