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authorHans Bolinder <[email protected]>2014-10-23 09:02:28 +0200
committerHans Bolinder <[email protected]>2014-10-23 09:02:28 +0200
commit527ae7b5030ba7339eba5ba4089888c8f90e2879 (patch)
treeffd9350604b0f02cee5ea8de8e77c50dd5966597 /lib/stdlib
parentaeeda10c7ada4f81add3cb9c0b8205cc15168675 (diff)
parentff3fae223431a9cb0d2a2852a07f9447960c92ed (diff)
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Merge branch 'maint'
* maint: Fix rare race condition in Dets
Diffstat (limited to 'lib/stdlib')
-rw-r--r--lib/stdlib/src/dets.erl25
-rw-r--r--lib/stdlib/src/dets_server.erl18
-rw-r--r--lib/stdlib/test/dets_SUITE.erl138
3 files changed, 133 insertions, 48 deletions
diff --git a/lib/stdlib/src/dets.erl b/lib/stdlib/src/dets.erl
index 76e03bbfaa..a4bd45ea19 100644
--- a/lib/stdlib/src/dets.erl
+++ b/lib/stdlib/src/dets.erl
@@ -2839,17 +2839,22 @@ fsck_try(Fd, Tab, FH, Fname, SlotNumbers, Version) ->
tempfile(Fname) ->
Tmp = lists:concat([Fname, ".TMP"]),
- tempfile(Tmp, 10).
-
-tempfile(Tmp, 0) ->
- Tmp;
-tempfile(Tmp, N) ->
case file:delete(Tmp) of
- {error, eacces} -> % 'dets_process_died' happened anyway... (W-nd-ws)
- timer:sleep(1000),
- tempfile(Tmp, N-1);
- _ ->
- Tmp
+ {error, _Reason} -> % typically enoent
+ ok;
+ ok ->
+ assure_no_file(Tmp)
+ end,
+ Tmp.
+
+assure_no_file(File) ->
+ case file:read_file_info(File) of
+ {ok, _FileInfo} ->
+ %% Wait for some other process to close the file:
+ timer:sleep(100),
+ assure_no_file(File);
+ {error, _} ->
+ ok
end.
%% -> {ok, NewHead} | {try_again, integer()} | Error
diff --git a/lib/stdlib/src/dets_server.erl b/lib/stdlib/src/dets_server.erl
index 268c201047..3164d40f35 100644
--- a/lib/stdlib/src/dets_server.erl
+++ b/lib/stdlib/src/dets_server.erl
@@ -1,7 +1,7 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 2001-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2014. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
@@ -171,9 +171,15 @@ handle_info({pending_reply, {Ref, Result0}}, State) ->
link(Pid),
do_link(Store, FromPid),
true = ets:insert(Store, {FromPid, Tab}),
- true = ets:insert(?REGISTRY, {Tab, 1, Pid}),
- true = ets:insert(?OWNERS, {Pid, Tab}),
+ %% do_internal_open() has already done the following:
+ %% true = ets:insert(?REGISTRY, {Tab, 1, Pid}),
+ %% true = ets:insert(?OWNERS, {Pid, Tab}),
{ok, Tab};
+ {Reply, internal_open} ->
+ %% Clean up what do_internal_open() did:
+ true = ets:delete(?REGISTRY, Tab),
+ true = ets:delete(?OWNERS, Pid),
+ Reply;
{Reply, _} -> % ok or Error
Reply
end,
@@ -309,6 +315,12 @@ do_internal_open(State, From, Args) ->
[T, _, _] -> T;
[_, _] -> Ref
end,
+ %% Pretend the table is open. If someone else tries to
+ %% open the file it will always become a pending
+ %% 'add_user' request. If someone tries to use the table
+ %% there will be a delay, but that is OK.
+ true = ets:insert(?REGISTRY, {Tab, 1, Pid}),
+ true = ets:insert(?OWNERS, {Pid, Tab}),
pending_call(Tab, Pid, Ref, From, Args, internal_open, State);
Error ->
{Error, State}
diff --git a/lib/stdlib/test/dets_SUITE.erl b/lib/stdlib/test/dets_SUITE.erl
index 119b4dc7cb..3b08ac165e 100644
--- a/lib/stdlib/test/dets_SUITE.erl
+++ b/lib/stdlib/test/dets_SUITE.erl
@@ -223,8 +223,7 @@ open(Config, Version) ->
?format("Crashing dets server \n", []),
process_flag(trap_exit, true),
- Procs = [whereis(?DETS_SERVER) | map(fun(Tab) -> dets:info(Tab, pid) end,
- Tabs)],
+ Procs = [whereis(?DETS_SERVER) | [dets:info(Tab, pid) || Tab <- Tabs]],
foreach(fun(Pid) -> exit(Pid, kill) end, Procs),
timer:sleep(100),
c:flush(), %% flush all the EXIT sigs
@@ -235,18 +234,32 @@ open(Config, Version) ->
open_files(1, All, Version),
?format("Checking contents of repaired files \n", []),
check(Tabs, Data),
-
- close_all(Tabs),
+ close_all(Tabs),
delete_files(All),
- P1 = pps(),
+
{Ports0, Procs0} = P0,
- {Ports1, Procs1} = P1,
- true = Ports1 =:= Ports0,
- %% The dets_server process has been restarted:
- [_] = Procs0 -- Procs1,
- [_] = Procs1 -- Procs0,
- ok.
+ Test = fun() ->
+ P1 = pps(),
+ {Ports1, Procs1} = P1,
+ show("Old port", Ports0 -- Ports1),
+ show("New port", Ports1 -- Ports0),
+ show("Old procs", Procs0 -- Procs1),
+ show("New procs", Procs1 -- Procs0),
+ io:format("Remaining Dets-pids (should be nil): ~p~n",
+ [find_dets_pids()]),
+ true = Ports1 =:= Ports0,
+ %% The dets_server process has been restarted:
+ [_] = Procs0 -- Procs1,
+ [_] = Procs1 -- Procs0,
+ ok
+ end,
+ case catch Test() of
+ ok -> ok;
+ _ ->
+ timer:sleep(500),
+ ok = Test()
+ end.
check(Tabs, Data) ->
foreach(fun(Tab) ->
@@ -3275,12 +3288,22 @@ simultaneous_open(Config) ->
File = filename(Tab, Config),
ok = monit(Tab, File),
- ok = kill_while_repairing(Tab, File),
- ok = kill_while_init(Tab, File),
- ok = open_ro(Tab, File),
- ok = open_w(Tab, File, 0, Config),
- ok = open_w(Tab, File, 100, Config),
- ok.
+ case feasible() of
+ false -> {comment, "OK, but did not run all of the test"};
+ true ->
+ ok = kill_while_repairing(Tab, File),
+ ok = kill_while_init(Tab, File),
+ ok = open_ro(Tab, File),
+ ok = open_w(Tab, File, 0, Config),
+ ok = open_w(Tab, File, 100, Config)
+ end.
+
+feasible() ->
+ LP = erlang:system_info(logical_processors),
+ (is_integer(LP)
+ andalso LP >= erlang:system_info(schedulers_online)
+ andalso not erlang:system_info(debug_compiled)
+ andalso not erlang:system_info(lock_checking)).
%% One process logs and another process closes the log. Before
%% monitors were used, this would make the client never return.
@@ -3307,7 +3330,6 @@ kill_while_repairing(Tab, File) ->
Delay = 1000,
dets:start(),
Parent = self(),
- Ps = processes(),
F = fun() ->
R = (catch dets:open_file(Tab, [{file,File}])),
timer:sleep(Delay),
@@ -3318,7 +3340,7 @@ kill_while_repairing(Tab, File) ->
P1 = spawn(F),
P2 = spawn(F),
P3 = spawn(F),
- DetsPid = find_dets_pid([P1, P2, P3 | Ps]),
+ DetsPid = find_dets_pid(),
exit(DetsPid, kill),
receive {P1,R1} -> R1 end,
@@ -3342,12 +3364,6 @@ kill_while_repairing(Tab, File) ->
file:delete(File),
ok.
-find_dets_pid(P0) ->
- case lists:sort(processes() -- P0) of
- [P, _] -> P;
- _ -> timer:sleep(100), find_dets_pid(P0)
- end.
-
find_dets_pid() ->
case find_dets_pids() of
[] ->
@@ -3421,6 +3437,13 @@ open_ro(Tab, File) ->
open_w(Tab, File, Delay, Config) ->
create_opened_log(File),
+
+ Tab2 = t2,
+ File2 = filename(Tab2, Config),
+ file:delete(File2),
+ {ok,Tab2} = dets:open_file(Tab2, [{file,File2}]),
+ ok = dets:close(Tab2),
+
Parent = self(),
F = fun() ->
R = dets:open_file(Tab, [{file,File}]),
@@ -3430,16 +3453,16 @@ open_w(Tab, File, Delay, Config) ->
Pid1 = spawn(F),
Pid2 = spawn(F),
Pid3 = spawn(F),
- undefined = dets:info(Tab), % is repairing now
- 0 = qlen(),
- Tab2 = t2,
- File2 = filename(Tab2, Config),
- file:delete(File2),
+ ok = wait_for_repair_to_start(Tab),
+
+ %% It is assumed that it takes some time to repair the file.
{ok,Tab2} = dets:open_file(Tab2, [{file,File2}]),
+ %% The Dets server managed to handle to open_file request.
+ 0 = qlen(), % still repairing
+
ok = dets:close(Tab2),
file:delete(File2),
- 0 = qlen(), % still repairing
receive {Pid1,R1} -> {ok, Tab} = R1 end,
receive {Pid2,R2} -> {ok, Tab} = R2 end,
@@ -3456,6 +3479,15 @@ open_w(Tab, File, Delay, Config) ->
file:delete(File),
ok.
+wait_for_repair_to_start(Tab) ->
+ case catch dets_server:get_pid(Tab) of
+ {'EXIT', _} ->
+ timer:sleep(1),
+ wait_for_repair_to_start(Tab);
+ Pid when is_pid(Pid) ->
+ ok
+ end.
+
qlen() ->
{_, {_, N}} = lists:keysearch(message_queue_len, 1, process_info(self())),
N.
@@ -4350,6 +4382,7 @@ check_badarg({'EXIT', {badarg, [{M,F,A,_} | _]}}, M, F, Args) ->
true = test_server:is_native(M) andalso length(Args) =:= A.
check_pps({Ports0,Procs0} = P0) ->
+ ok = check_dets_tables(),
case pps() of
P0 ->
ok;
@@ -4375,13 +4408,45 @@ check_pps({Ports0,Procs0} = P0) ->
end
end.
+%% Copied from dets_server.erl:
+-define(REGISTRY, dets_registry).
+-define(OWNERS, dets_owners).
+-define(STORE, dets).
+
+check_dets_tables() ->
+ Store = [T ||
+ T <- ets:all(),
+ ets:info(T, name) =:= ?STORE,
+ owner(T) =:= dets],
+ S = case Store of
+ [Tab] -> ets:tab2list(Tab);
+ [] -> []
+ end,
+ case {ets:tab2list(?REGISTRY), ets:tab2list(?OWNERS), S} of
+ {[], [], []} -> ok;
+ {R, O, _} ->
+ io:format("Registry: ~p~n", [R]),
+ io:format("Owners: ~p~n", [O]),
+ io:format("Store: ~p~n", [S]),
+ not_ok
+ end.
+
+owner(Tab) ->
+ Owner = ets:info(Tab, owner),
+ case process_info(Owner, registered_name) of
+ {registered_name, Name} -> Name;
+ _ -> Owner
+ end.
+
show(_S, []) ->
ok;
-show(S, [Pid|Pids]) when is_pid(Pid) ->
- io:format("~s: ~p~n", [S, erlang:process_info(Pid)]),
+show(S, [{Pid, Name, InitCall}|Pids]) when is_pid(Pid) ->
+ io:format("~s: ~w (~w), ~w: ~p~n",
+ [S, Pid, proc_reg_name(Name), InitCall,
+ erlang:process_info(Pid)]),
show(S, Pids);
-show(S, [Port|Ports]) when is_port(Port)->
- io:format("~s: ~p~n", [S, erlang:port_info(Port)]),
+show(S, [{Port, _}|Ports]) when is_port(Port)->
+ io:format("~s: ~w: ~p~n", [S, Port, erlang:port_info(Port)]),
show(S, Ports).
pps() ->
@@ -4397,5 +4462,8 @@ process_list() ->
safe_second_element(process_info(P, initial_call))} ||
P <- processes()].
+proc_reg_name({registered_name, Name}) -> Name;
+proc_reg_name([]) -> no_reg_name.
+
safe_second_element({_,Info}) -> Info;
safe_second_element(Other) -> Other.