Module: Mongo::Locking::ModelMethods::InstanceMethods

Defined in:
lib/mongo/locking/model_methods.rb

Overview

ClassMethods

Instance Method Summary collapse

Instance Method Details

#lock(opts = {}) ⇒ Object

Main closure-based lock method. opts remains present for future utility.



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# File 'lib/mongo/locking/model_methods.rb', line 64

def lock(opts = {})
    raise ArgumentError, "#{self.class.name}#lock requires a block" unless block_given?

    # Look for the top level lockable
    lockable = self.class.locker.root_for(self)

    # Try to acquire the lock. If succeeds, "locked" will be set
    locked = lockable.class.locker.acquire(lockable)

    return yield

rescue => e
    Locking.error "#{self.class.name}#lock failed"
    raise e

ensure
    # Only unlock if "locked" was set.  We're using this to
    # distinguish between an exception from the yield vs. an
    # exception from our own locking code.  Doing it in an
    # ensure block makes us defensible against a return from
    # within the closure, too.
    #
    # Calling lockable's locker instead of self potentially
    # saves us the cost of "find root lockable" that locker
    # would perform.
    lockable.class.locker.release(lockable) if locked
end