grmd

Grmd is a software that can be used as a general resource management solution for Unix-like systems. It is specifically designed to provide exclusive lock control over files and other resources. Typically, programmers use busy-wait methods, mkdir(), symlink(), flock(), lockf(), fcntl(), or semaphores for exclusive lock control. However, the quality level of exclusive lock control varies depending on the programmer's skill level. This makes it challenging to get unified exclusive lock control throughout the system.

Even if a programmer designs excellent exclusive lock control, there can be unavoidable difficulties like the deadlock problem. Grmd provides a solution to this problem by controlling exclusive lock with client-server methods. As a result, you can control exclusive lock over every resource with a unified interface.

Some key features of Grmd include the 2-level exclusive lock (SHARED_LOCK, EXCUSIVE_LOCK), which helps multiplex. If a resource is locked by another process, the process goes into sleep mode instead of busy-waiting. Additionally, the process wakes up automatically when the resource is released by another process. Grmd also informs the client instantly when a deadlock occurs.

The latest release of Grmd has made the following changes:

- Improvements to the daemon code and option handling.
- Improved signal handling.
- The default host is now NADDR_ANY.
- The maximum length of pid, resid, and key was increased from 64 to 256.
- A bug causing a segmentation fault when access was denied by libwrap was fixed.

Overall, Grmd provides an efficient, user-friendly solution for exclusive lock control. Its features and updated release make it a valuable addition to any Unix-like system.