PG::LockNotAvailable rescue woes

pg_locking.rb

def save_with_lock
  r = Record.first
  
  # This will raise PG::LockNotAvailable if already locked
  #
  r.with_lock("FOR UPDATE NOWAIT") do
    # do stuff
  end
  
# This rescue block isn't executed for some reason??
#
rescue PG::LockNotAvailable
  puts "lock not available"
  
# But this one works
#
rescue ActiveRecord::StatementInvalid => e
  if e.message.include? "LockNotAvailable"
    puts "lock not available"
  else
    raise
  end
end

@hoverlover hi there! thanks for posting this workaround. i'm experiencing the same woes in one of my rails projects. just curious - did you ever find out why PG::LockNotAvailable doesn't get rescued here?

rescue ActiveRecord::StatementInvalid => exception
        raise exception unless exception.cause.is_a? PG::LockNotAvailable

@sethsweepnovu I've always wondering, why not just using rescue ActiveRecord::LockWaitTimeout without care about the bubbled error?

@ktravers

did you ever find out why PG::LockNotAvailable doesn't get rescued here?

PG::LockNotAvailable It is a parent error, the current error being ActiveRecord::LockWaitTimeout. Hence you can find it in e.cause