Fix and test for file descriptor leaks

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@748299 13f79535-47bb-0310-9956-ffa450edef68

4 files changed, 8 insertions, 73 deletions

diff --git a/src/couchdb/Makefile.am b/src/couchdb/Makefile.am
index dc48c983..51e4878c 100644
--- a/src/couchdb/Makefile.am
+++ b/src/couchdb/Makefile.am
@@ -51,7 +51,6 @@ source_files = \
     couch_external_manager.erl \
     couch_external_server.erl \
     couch_file.erl \
-    couch_file_stats.erl \
     couch_httpd.erl \
     couch_httpd_db.erl \
     couch_httpd_external.erl \
@@ -92,7 +91,6 @@ compiled_files = \
     couch_external_manager.beam \
     couch_external_server.beam \
     couch_file.beam \
-    couch_file_stats.beam \
     couch_httpd.beam \
     couch_httpd_db.beam \
     couch_httpd_external.beam \
diff --git a/src/couchdb/couch_file.erl b/src/couchdb/couch_file.erl
index d1103030..364eafd6 100644
--- a/src/couchdb/couch_file.erl
+++ b/src/couchdb/couch_file.erl
@@ -35,7 +35,6 @@ open(Filepath, Options) ->
     case gen_server:start_link(couch_file,
             {Filepath, Options, self(), Ref = make_ref()}, []) of
     {ok, Fd} ->
-        couch_file_stats:track_file(Fd),
         {ok, Fd};
     ignore ->
         % get the error
@@ -270,6 +269,7 @@ init_status_error(ReturnPid, Ref, Error) ->
 % server functions
 
 init({Filepath, Options, ReturnPid, Ref}) ->
+    process_flag(trap_exit, true),
     case lists:member(create, Options) of
     true ->
         filelib:ensure_dir(Filepath),
@@ -285,12 +285,14 @@ init({Filepath, Options, ReturnPid, Ref}) ->
                 true ->
                     {ok, 0} = file:position(Fd, 0),
                     ok = file:truncate(Fd),
+                    couch_stats_collector:increment({couchdb, os_files_open}),
                     {ok, Fd};
                 false ->
                     ok = file:close(Fd),
                     init_status_error(ReturnPid, Ref, file_exists)
                 end;
             false ->
+                couch_stats_collector:increment({couchdb, os_files_open}),
                 {ok, Fd}
             end;
         Error ->
@@ -302,6 +304,7 @@ init({Filepath, Options, ReturnPid, Ref}) ->
         {ok, Fd_Read} ->
             {ok, Fd} = file:open(Filepath, [read, write, raw, binary]),
             ok = file:close(Fd_Read),
+            couch_stats_collector:increment({couchdb, os_files_open}),
             {ok, Fd};
         Error ->
             init_status_error(ReturnPid, Ref, Error)
@@ -310,6 +313,7 @@ init({Filepath, Options, ReturnPid, Ref}) ->
 
 
 terminate(_Reason, _Fd) ->
+    couch_stats_collector:decrement({couchdb, os_files_open}),
     ok.
 
 
@@ -345,5 +349,5 @@ handle_cast(close, Fd) ->
 code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
-handle_info(foo, Fd) ->
-    {stop, foo, Fd}.
+handle_info({'EXIT', _, Reason}, Fd) ->
+    {stop, Reason, Fd}.
diff --git a/src/couchdb/couch_file_stats.erl b/src/couchdb/couch_file_stats.erl
deleted file mode 100644
index 5e7d550b..00000000
--- a/src/couchdb/couch_file_stats.erl
+++ /dev/null
@@ -1,68 +0,0 @@
-% Licensed under the Apache License, Version 2.0 (the "License"); you may not
-% use this file except in compliance with the License.  You may obtain a copy of
-% the License at
-%
-%   http://www.apache.org/licenses/LICENSE-2.0
-%
-% Unless required by applicable law or agreed to in writing, software
-% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
-% License for the specific language governing permissions and limitations under
-% the License.
-
--module(couch_file_stats).
--behaviour(gen_server).
-
--export([init/1, terminate/2, handle_call/3, handle_cast/2, code_change/3,
-        handle_info/2]).
-
--export([start_link/0,track_file/1,get_stats/0]).
-
--record(stats,{
-    opened=0,
-    closed=0
-    }).
-
-
-track_file(Fd) ->
-    catch gen_server:cast(couch_file_stats, {track, Fd}).
-
-
-get_stats() ->
-    #stats{opened=Opened,closed=Closed}=gen_server:call(couch_file_stats,get),
-    [{files_open,Opened-Closed}, {files_closed,Closed}].
-
-
-start_link() ->
-    gen_server:start_link({local, couch_file_stats}, couch_file_stats, [], []).
-
-
-init([]) ->
-    {ok, #stats{}}.
-
-
-terminate(_Reason, _Fd) ->
-    ok.
-
-
-handle_call(get, _From, Stats) ->
-    {reply, Stats, Stats}.
-
-
-handle_cast({track, Fd}, #stats{opened=Opened,closed=Closed}=Stats) ->
-    try erlang:monitor(process, Fd) of
-    _Ref ->
-        {noreply, Stats#stats{opened=Opened+1}}
-    catch
-    _Error ->
-        {noreply, Stats#stats{opened=Opened+1, closed=Closed+1}}
-    end.
-
-
-handle_info({'DOWN',_MonRef,_Type,_Pid,_Info}, #stats{closed=Closed}=Stats) ->
-    {noreply, Stats#stats{closed=Closed+1}}.
-
-
-code_change(_OldVsn, State, _Extra) ->
-    {ok, State}.
-
diff --git a/src/couchdb/couch_stats_aggregator.erl b/src/couchdb/couch_stats_aggregator.erl
index 2a1e5797..eef8f22f 100644
--- a/src/couchdb/couch_stats_aggregator.erl
+++ b/src/couchdb/couch_stats_aggregator.erl
@@ -299,6 +299,7 @@ init_descriptions() ->
     ets:insert(?MODULE, {{couchdb, database_changes}, <<"Number of times a database was changed">>}),
     ets:insert(?MODULE, {{couchdb, database_reads}, <<"Number of times a document was read from a database">>}),
     ets:insert(?MODULE, {{couchdb, open_databases}, <<"Number of open databases">>}),
+    ets:insert(?MODULE, {{couchdb, os_files_open}, <<"Number of file descriptors CouchDB has open.">>}),
     ets:insert(?MODULE, {{couchdb, request_time}, <<"Length of a request inside CouchDB without Mochiweb">>}),
 
     ets:insert(?MODULE, {{http_status_codes, '200'}, <<"Number of HTTP 200 OK responses">>}),