SYNOPSIS: |
methods to add posix (fcntl based and nfs safe) locking to the builtin File
class
URLS:
- http://raa.ruby-lang.org/project/posixlock/
- Index of /lib/ruby/posixlock
EXAMPLES:
- |
File.open('even_an_nfs_mounted_file','r+').posixlock File::LOCK_EX
- |
File.open('even_an_nfs_mounted_file','r+').lockf File::F_LOCK, 0
- |
open('even_an_nfs_mounted_file','r') do |f|
f.lockf File::F_LOCKR, 42
end
- |
f = open 'foo', 'r+'
if((pid = f.lockf File::F_TEST, 0))
STDERR.puts "process <#{ pid }> prevents write lock"
end
- |
f = open 'foo', 'r'
if((pid = f.lockf File::F_TESTR, 0))
STDERR.puts "process <#{ pid }> prevents read lock"
end
DOCS:
- posixlock.c
- File#posixlock has an identical interface to the builtin File#flock
- |
for File#lockf see man (3) lockf
the additional flags
File::F_LOCKR
File::F_LOCKW
File::F_TLOCKR
File::F_TLOCKW
File::F_TESTR
File::F_TESTW
have the obvious meaning
AUTHOR: |
ara.t.howard@noaa.gov
BUGS: |
> 1
HISTORY:
1.0.0: |
changed behaviour so that, instead of replacing flock, two new methods are
added: File#posixlock gives access to read/write locks with an interface
identical to File#flock, and File#lockf gives access to a lockf impl
similar to the one posix specifies with added functionality for read
locks. the biggest difference between the two methods is that lockf will
throw errors for errno's like EAGAIN, EACCESS, etc.
0.0.0: |
initial version
-a