updated container handling. hopefully removed potential error source.

lib/docker_client.rb

@@ -188,7 +188,17 @@ class DockerClient
       {status: :ok, stderr: stderr.join, stdout: stdout.join}
     end
   rescue Timeout::Error
-    container.restart if RECYCLE_CONTAINERS
+    #container.restart if RECYCLE_CONTAINERS
+    DockerContainerPool.remove_from_all_containers(container, @execution_environment)
+
+    # destroy container
+    destroy_container(container)
+
+    if(RECYCLE_CONTAINERS)
+      # create new container and add it to @all_containers. will be added to @containers on return_container
+      container = create_container(execution_environment)
+      DockerContainerPool.add_to_all_containers(container, execution_environment)
+    end
     {status: :timeout}
   ensure
     RECYCLE_CONTAINERS ? return_container(container) : self.class.destroy_container(container)

lib/docker_container_pool.rb

@@ -19,6 +19,20 @@ class DockerContainerPool
     @config ||= CodeOcean::Config.new(:docker).read(erb: true)[:pool]
   end
 
+  def self.remove_from_all_containers(container, execution_environment)
+    @all_containers[execution_environment.id]-=[container]
+    if(@containers[execution_environment.id].include?(container))
+      @containers[execution_environment.id]-=[container]
+    end
+  end
+
+  def self.add_to_all_containers(container, execution_environment)
+    @all_containers[execution_environment.id]+=[container]
+    if(!@containers[execution_environment.id].include?(container))
+      @containers[execution_environment.id]+=[container]
+    end
+  end
+
   def self.create_container(execution_environment)
      container = DockerClient.create_container(execution_environment)
      container.status = 'available'
@@ -37,14 +51,14 @@ class DockerContainerPool
       if(!container.nil?)
         if ((Time.now - container.start_time).to_i.abs > TIME_TILL_RESTART)
           # remove container from @all_containers
-          @all_containers[execution_environment.id]-=[container]
+          remove_from_all_containers(container, execution_environment)
 
           # destroy container
           DockerClient.destroy_container(container)
 
           # create new container and add it to @all_containers. will be added to @containers on return_container
-          container = create_container(@execution_environment)
-          @all_containers[execution_environment.id]+=[container]
+          container = create_container(execution_environment)
+          add_to_all_containers(container, execution_environment)
         end
         #container.status = 'used'
       end