FlockEx

This library implements a simple wrapper around the C flock syscall for advisory locking

This gives you compatibility with linux command line utilities such as flock, or other apps which use the flock syscall

Remember that flock is an advisory syscall and will not prevent an app reading or writing to a given file, if it does not implement the flock checks. However, it's useful to be compatible with such utilities

Usage

  iex> {:ok, handle} = FlockEx.flock("#{System.tmp_dir}/lockme")
  {:ok, #Reference<0.2958773140.145358881.211403>}

  iex> FlockEx.unflock(handle)
  :ok

If the process holding the lock dies, then the flock will be automatically released.

If the flock lock goes out of scope, then the lock will be automatically released, but only when a garbage collection is run, which could be some time later. Ideally release the flock correctly

By default flock will take out an exclusive lock and wait forever for the lock to become available, this can be changed using params:

• exclusive: default true to take out an exclusive lock, false for a shared/read lock
• wait: default true to wait forever for a lock, false returns {:error, :eagain} if the lock cannot be obtained immediately

Installation

If available in Hex, the package can be installed by adding flock_ex to your list of dependencies in mix.exs:

def deps do
  [
    {:flock_ex, "~> 0.1.0"}
  ]
end