Merge branch 'stable'

2 files changed, 36 insertions, 2 deletions

diff --git a/src/rabbit.erl b/src/rabbit.erl
index b1f83729b8..d62a4b6935 100644
--- a/src/rabbit.erl
+++ b/src/rabbit.erl
@@ -507,6 +507,7 @@ await_startup(HaveSeenRabbitBoot) ->
 
 status() ->
     S1 = [{pid,                  list_to_integer(os:getpid())},
+          %% The timeout value used is twice that of gen_server:call/2.
           {running_applications, rabbit_misc:which_applications()},
           {os,                   os:type()},
           {erlang_version,       erlang:system_info(system_version)},
@@ -563,8 +564,9 @@ is_running() -> is_running(node()).
 is_running(Node) -> rabbit_nodes:is_process_running(Node, rabbit).
 
 environment() ->
+    %% The timeout value is twice that of gen_server:call/2.
     [{A, environment(A)} ||
-        {A, _, _} <- lists:keysort(1, application:which_applications())].
+        {A, _, _} <- lists:keysort(1, application:which_applications(10000))].
 
 environment(App) ->
     Ignore = [default_pass, included_applications],
diff --git a/src/rabbit_amqqueue_process.erl b/src/rabbit_amqqueue_process.erl
index 2db86391a5..5535a84fca 100644
--- a/src/rabbit_amqqueue_process.erl
+++ b/src/rabbit_amqqueue_process.erl
@@ -33,28 +33,60 @@
          prioritise_cast/3, prioritise_info/3, format_message_queue/2]).
 
 %% Queue's state
--record(q, {q,
+-record(q, {
+            %% an #amqqueue record
+            q,
+            %% none | {exclusive consumer channel PID, consumer tag}
             exclusive_consumer,
+            %% Set to true if a queue has ever had a consumer.
+            %% This is used to determine when to delete auto-delete queues.
             has_had_consumers,
+            %% backing queue module.
+            %% for mirrored queues, this will be rabbit_mirror_queue_master.
+            %% for non-priority and non-mirrored queues, rabbit_variable_queue.
+            %% see rabbit_backing_queue.
             backing_queue,
+            %% backing queue state.
+            %% see rabbit_backing_queue, rabbit_variable_queue.
             backing_queue_state,
+            %% consumers state, see rabbit_queue_consumers
             consumers,
+            %% queue expiration value
             expires,
+            %% timer used to periodically sync (flush) queue index
             sync_timer_ref,
+            %% timer used to update ingress/egress rates and queue RAM duration target
             rate_timer_ref,
+            %% timer used to clean up this queue due to TTL (on when unused)
             expiry_timer_ref,
+            %% stats emission timer
             stats_timer,
+            %% maps message IDs to {channel pid, MsgSeqNo}
+            %% pairs
             msg_id_to_channel,
+            %% message TTL value
             ttl,
+            %% timer used to delete expired messages
             ttl_timer_ref,
             ttl_timer_expiry,
+            %% Keeps track of channels that publish to this queue.
+            %% When channel process goes down, queues have to perform
+            %% certain cleanup.
             senders,
+            %% dead letter exchange as a #resource record, if any
             dlx,
             dlx_routing_key,
+            %% max length in messages, if configured
             max_length,
+            %% max length in bytes, if configured
             max_bytes,
             args_policy_version,
+            %% used to discard outdated/superseded policy updates,
+            %% e.g. when policies are applied concurrently. See
+            %% https://github.com/rabbitmq/rabbitmq-server/issues/803 for one
+            %% example.
             mirroring_policy_version = 0,
+            %% running | flow | idle
             status
            }).