Perl lock file while updating blog single woman dating
This seems to happen more frequently the more tuples are inserted at once, and I suspect it's a threading problem as it is never perfectly reproducible unless importing large data sets.
The solution to that is not exactly what you are being asked but it's to simply insert one record per statement.
All file locking algo works like this: While (file_is_locked()) lock_the file(); Do_somthing_on_file; unlock_the_file(); Its up to you to decide, what you mean when you say 'lock_the file();' I suggest to create lock file, so 'file_is_locked()' will mean checking existance of file.
This means that duplicate file descriptors (created by, for example, fork(2) or dup(2)) refer to the same lock, and this lock may be modified or released using any of these descriptors. The locks are merely advisory, so both the parent and the child (and all other processes) can still read and write from the file.
Hi, I want to lock the file in linux and the file cannot be edit or modify by other .
I know in perl, there is function flock , but it is not worked.
Furthermore, the lock is released either by an explicit LOCK_UN operation on any of these duplicate descriptors, or when all such descriptors have been closed. Therefore, the question then boils down to: Who should unlock the file?
On Free BSD, that's apparently up to you to decide: Locks are on files, not file descriptors.
now when you come you first check if exists, if it does not, you create it. so no one can 'lock' file x as long as is existing. If I want to lock a file x, ill create file in particular location.