Class: SafeFlock::Lockfile

Inherits:
Object
  • Object
show all
Defined in:
lib/safe_flock/lockfile.rb

Defined Under Namespace

Classes: Error, Locked

Constant Summary collapse

@@global_mutex = 
Mutex.new
@@path_mutex = 
{}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path, max_wait: 5.0) ⇒ Lockfile

path full pathname of mutually agreed lock file.

options

  • max_wait seconds to retry acquiring lock before giving up and raising Error (5.0)



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# File 'lib/safe_flock/lockfile.rb', line 18

def initialize(path, max_wait: 5.0)
  @pid = $$
  @thread_id = Thread.current.object_id
  @path = path
  @max_wait = max_wait
  @wait_per_try = 0.1
  @mlocked = false
  @lockfd = nil
end

Instance Attribute Details

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/safe_flock/lockfile.rb', line 54

def path
  @path
end

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/safe_flock/lockfile.rb', line 54

def pid
  @pid
end

#thread_id ⇒ Object (readonly)

Returns the value of attribute thread_id.



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# File 'lib/safe_flock/lockfile.rb', line 54

def thread_id
  @thread_id
end

Instance Method Details

#lock ⇒ Object 



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# File 'lib/safe_flock/lockfile.rb', line 28

def lock
  deadline = Time.now.to_f + @max_wait
  while !(is_locked = try_lock)
    if Time.now.to_f < deadline
      sleep @wait_per_try
    else
      break
    end
  end
  is_locked
end

#unlock ⇒ Object

If the lock is inherited by a forked child process, it will hold the lock until the child calls unlock (or terminates) and the parent’s Lockfile.create block terminates. The parent should not call unlock.



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# File 'lib/safe_flock/lockfile.rb', line 44

def unlock
  if @lockfd
    @lockfd.close
    @lockfd = nil
  end
  if @mlocked && @pid == $$ and @thread_id == Thread.current.object_id
    mutex_unlock
  end
end