From f35645e051eb0939a08820a044f847f4c6a942f5 Mon Sep 17 00:00:00 2001
From: Martin Edenhofer <me@edenhofer.de>
Date: Tue, 22 Aug 2017 19:36:48 +0200
Subject: [PATCH] Prevent database dead locks.

---
 app/controllers/taskbar_controller.rb                |  8 ++++++--
 app/models/observer/organization/ref_object_touch.rb | 12 ++++++++++--
 app/models/taskbar.rb                                |  8 +++++---
 3 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/app/controllers/taskbar_controller.rb b/app/controllers/taskbar_controller.rb
index dd4cd7b61..ade959ade 100644
--- a/app/controllers/taskbar_controller.rb
+++ b/app/controllers/taskbar_controller.rb
@@ -21,14 +21,18 @@ class TaskbarController < ApplicationController
   def update
     taskbar = Taskbar.find(params[:id])
     access(taskbar)
-    taskbar.update_attributes!(Taskbar.param_cleanup(params))
+    taskbar.with_lock do
+      taskbar.update_attributes!(Taskbar.param_cleanup(params))
+    end
     model_update_render_item(taskbar)
   end
 
   def destroy
     taskbar = Taskbar.find(params[:id])
     access(taskbar)
-    taskbar.destroy
+    taskbar.with_lock do
+      taskbar.destroy
+    end
     model_destroy_render_item()
   end
 
diff --git a/app/models/observer/organization/ref_object_touch.rb b/app/models/observer/organization/ref_object_touch.rb
index 043113b28..beec37fd4 100644
--- a/app/models/observer/organization/ref_object_touch.rb
+++ b/app/models/observer/organization/ref_object_touch.rb
@@ -24,11 +24,19 @@ class Observer::Organization::RefObjectTouch < ActiveRecord::Observer
     return if User.where(organization_id: record.id).count > 100
 
     # touch organizations tickets
-    Ticket.select('id').where(organization_id: record.id).each(&:touch)
+    Ticket.select('id').where(organization_id: record.id).pluck(:id).each { |ticket_id|
+      ticket = Ticket.find(ticket_id)
+      ticket.with_lock do
+        ticket.touch
+      end
+    }
 
     # touch current members
     record.member_ids.uniq.each { |user_id|
-      User.find(user_id).touch
+      user = User.find(user_id)
+      user.with_lock do
+        user.touch
+      end
     }
   end
 end
diff --git a/app/models/taskbar.rb b/app/models/taskbar.rb
index f4614a15c..63c64d860 100644
--- a/app/models/taskbar.rb
+++ b/app/models/taskbar.rb
@@ -88,9 +88,11 @@ class Taskbar < ApplicationModel
     # update other taskbars
     Taskbar.where(key: key).order(:created_at, :id).each { |taskbar|
       next if taskbar.id == id
-      taskbar.preferences = preferences
-      taskbar.local_update = true
-      taskbar.save!
+      taskbar.with_lock do
+        taskbar.preferences = preferences
+        taskbar.local_update = true
+        taskbar.save!
+      end
     }
 
     return true if destroyed?