deepak@ncst.ernet.in (Deepak G Patil) (06/25/91)
Does any one know how to lock records in C-tree on bsd unix ? to my knowledge to lock records C-tree uses system call, and bsd unix doesn't support any system call to lock a record in a file, has any one implemented record locking under bsd unix? any pointers will be highly appreciated. thanks in advance. Deepak
jhc@ivan.uucp (James H. Coombs) (06/25/91)
In article <1991Jun25.091645.28309@ncst.ernet.in> deepak@ncst.ernet.in (Deepak G Patil) writes: >Does any one know how to lock records in C-tree on bsd unix ? > >to my knowledge to lock records C-tree uses system call, >and bsd unix doesn't support any system call to lock a record in a file, c-tree invokes lockf(). I find that when we were working on the IBM RT, I defined lockf() to (0), but I did not have a multi-user application on that machine. There are many ways to implement locking: 1. Write a lock demon that mediates between processes. 2. Use a multi-threaded server that keeps track of locked records. 3. Put a flag in each record to indicate whether or not it is locked. 4. If simultaneous locking is limited, use flock() and lock the entire table. --Jim