Use a journalized-scope advisory lock to minimize exclusive locks

This commit removes transactional_lock (mysql-support only) with
`with_advisory_lock` which supports both MySQL and PostgresSQL.

For PostgreSQL, which supports more than one advisory lock per session,
we can reference the customized type and ID to minimize the locking we
do for other work packages.

Gemfile

@@ -138,8 +138,7 @@ gem 'lograge', '~> 0.10.0'
 # don't require by default, instead load on-demand when actually configured
 gem 'airbrake', '~> 8.0.1', require: false
 
-gem 'transactional_lock', git: 'https://github.com/finnlabs/transactional_lock.git',
-                          branch: 'master'
+gem 'with_advisory_lock'
 
 gem 'prawn', '~> 2.2'
 gem 'prawn-table', '~> 0.2.2'

Gemfile.lock

@@ -38,14 +38,6 @@ GIT
   specs:
     rspec-example_disabler (0.0.1)
 
-GIT
-  remote: https://github.com/finnlabs/transactional_lock.git
-  revision: 6948b1d446db0da5645e68ffeeddca1c4944c3bc
-  branch: master
-  specs:
-    transactional_lock (0.1.0)
-      activerecord (>= 4.0)
-
 GIT
   remote: https://github.com/goodwill/capybara-select2
   revision: 585192e4bb0db8d52e761ab68f08c17294806447
@@ -898,6 +890,8 @@ GEM
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.3)
     will_paginate (3.1.6)
+    with_advisory_lock (4.0.0)
+      activerecord (>= 4.2)
     xpath (3.2.0)
       nokogiri (~> 1.8)
 
@@ -1055,7 +1049,6 @@ DEPENDENCIES
   test-prof (~> 0.7.3)
   thin (~> 1.7.2)
   timecop (~> 0.9.0)
-  transactional_lock!
   typed_dag (~> 2.0.2)
   tzinfo-data (~> 1.2018.9)
   unicorn
@@ -1064,6 +1057,7 @@ DEPENDENCIES
   warden-basic_auth (~> 0.2.1)
   webmock (~> 3.5.0)
   will_paginate (~> 3.1.0)
+  with_advisory_lock
 
 RUBY VERSION
    ruby 2.6.1p33

app/models/journal.rb

@@ -59,19 +59,17 @@ class Journal < ActiveRecord::Base
   # Note for PostgreSQL: If this is called from inside a transaction, the lock will last until the
   #   end of that transaction.
   # Note for MySQL: THis method does not currently change anything (no locking at all)
-  def self.with_write_lock
+  def self.with_write_lock(journable)
+    lock_name =
     if OpenProject::Database.mysql?
-      Journal.transaction do
-        # MySQL is very weak when combining transactions and locks. Using an emulation layer to
-        # automatically release an advisory lock at the end of the transaction
-        TransactionalLock::AdvisoryLock.new('journals.write_lock').acquire
-        yield
-      end
+      # MySQL only supports a single lock
+      "journals.write_lock"
     else
-      Journal.transaction do
-        ActiveRecord::Base.connection.execute("LOCK TABLE #{table_name} IN SHARE ROW EXCLUSIVE MODE")
-        yield
-      end
+      "journal.#{journable.class}.#{journable.id}"
+    end
+
+    Journal.with_advisory_lock(lock_name, timeout_seconds: 60) do
+      yield
     end
   end
 

app/models/journal_manager.rb

@@ -227,7 +227,8 @@ class JournalManager
   def self.add_journal!(journable, user = User.current, notes = '')
     if journalized? journable
       # Obtain a table lock to ensure consistent version numbers
-      Journal.with_write_lock do
+      Journal.with_write_lock(journable) do
+
         # Maximum version might be nil, so use to_i here.
         version = journable.journals.maximum(:version).to_i + 1
 

config/initializers/transactional_lock.rb

@@ -1,36 +0,0 @@
-#-- encoding: UTF-8
-#-- copyright
-# OpenProject is a project management system.
-# Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License version 3.
-#
-# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
-# Copyright (C) 2006-2017 Jean-Philippe Lang
-# Copyright (C) 2010-2013 the ChiliProject Team
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License
-# as published by the Free Software Foundation; either version 2
-# of the License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
-#
-# See docs/COPYRIGHT.rdoc for more details.
-#++
-
-OpenProject::Application.configure do
-  config.after_initialize do
-    TransactionalLock.initialize do |config|
-      config.merge(default_timeout: 60)
-    end
-  end
-end