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-rw-r--r--lib/tools/doc/src/lcnt_chapter.xml26
-rw-r--r--lib/tools/test/lcnt_SUITE.erl85
2 files changed, 91 insertions, 20 deletions
diff --git a/lib/tools/doc/src/lcnt_chapter.xml b/lib/tools/doc/src/lcnt_chapter.xml
index 6cfdb5cf1b..362f212963 100644
--- a/lib/tools/doc/src/lcnt_chapter.xml
+++ b/lib/tools/doc/src/lcnt_chapter.xml
@@ -48,29 +48,19 @@
</p>
<section>
<title> Enabling lock-counting </title>
- <p>For investigation of locks in the emulator we use an internal tool called <c>lcnt</c> (short for lock-count). The VM needs to be compiled with this option enabled. To enable this, use:</p>
+ <p>For investigation of locks in the emulator we use an internal tool called <c>lcnt</c> (short for lock-count). The VM needs to be compiled with this option enabled.
+ To compile a lock-counting VM along with a normal VM, use:</p>
<pre>
cd $ERL_TOP
-./configure --enable-lock-counter
- </pre>
-
- <p>
- Another way to enable this alongside a normal VM is to compile it at emulator directory level, much like a debug build. To compile it this way do the following,
- </p>
- <pre>
-cd $ERL_TOP/erts/emulator
-make lcnt FLAVOR=smp
- </pre>
- <p> and then starting Erlang with,</p>
+./configure --enable-lock-counter</pre>
+ <p>Start the lock-counting VM like this:</p>
<pre>
-$ERL_TOP/bin/cerl -lcnt
- </pre>
- <p>To verify that you lock-counting enabled check that <c>[lock-counting]</c> appears in the status text when the VM is started.</p>
+$ERL_TOP/bin/erl -emu_type lcnt</pre>
+ <p>To verify that lock counting is enabled check that <c>[lock-counting]</c> appears in the status text when the VM is started.</p>
<pre>
-Erlang R13B03 (erts-5.7.4) [source] [64-bit] [smp:8:8] [rq:8] [async-threads:0] [hipe]
- [kernel-poll:false] [lock-counting]
- </pre>
+Erlang/OTP 20 [erts-9.0] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe]
+ [kernel-poll:false] [lock-counting]</pre>
</section>
<section>
<title>Getting started</title>
diff --git a/lib/tools/test/lcnt_SUITE.erl b/lib/tools/test/lcnt_SUITE.erl
index d39a5deeab..2e48b11740 100644
--- a/lib/tools/test/lcnt_SUITE.erl
+++ b/lib/tools/test/lcnt_SUITE.erl
@@ -29,7 +29,8 @@
-export([t_load/1,
t_conflicts/1,
t_locations/1,
- t_swap_keys/1]).
+ t_swap_keys/1,
+ smoke_lcnt/1]).
init_per_testcase(_Case, Config) ->
Config.
@@ -43,7 +44,8 @@ suite() ->
{timetrap,{minutes,4}}].
all() ->
- [t_load, t_conflicts, t_locations, t_swap_keys].
+ [t_load, t_conflicts, t_locations, t_swap_keys,
+ smoke_lcnt].
%%----------------------------------------------------------------------
%% Tests
@@ -146,3 +148,82 @@ t_swap_keys_file([File|Files]) ->
ok = lcnt:conflicts(),
ok = lcnt:stop(),
t_swap_keys_file(Files).
+
+%% Simple smoke test of actual lock-counting, if running on
+%% a run-time with lock-counting enabled.
+
+smoke_lcnt(Config) ->
+ case erlang:system_info(build_type) of
+ lcnt ->
+ do_smoke_lcnt(Config);
+ _ ->
+ {skip,"Lock counting is not enabled"}
+ end.
+
+do_smoke_lcnt(Config) ->
+ PrivDir = proplists:get_value(priv_dir, Config),
+ SaveFile = filename:join(PrivDir, atom_to_list(?FUNCTION_NAME)),
+ {Time,ok} = timer:tc(fun() -> lcnt:apply(fun() -> big_bang(200) end) end),
+ io:format("~p ms\n", [Time]),
+ ok = lcnt:conflicts(),
+ ok = lcnt:save(SaveFile),
+ ok = lcnt:load(SaveFile),
+ ok = lcnt:conflicts(),
+ lcnt:stop().
+
+
+%%%
+%%% A slightly modified version of Rickard Green's Big Bang benchmark.
+%%%
+
+big_bang(N) when is_integer(N) ->
+ Procs = spawn_procs(N),
+ RMsgs = lists:map(fun (P) -> {done, P} end, Procs),
+ send_procs(Procs, {procs, Procs, self()}),
+ receive_msgs(RMsgs),
+ lists:foreach(fun (P) -> exit(P, normal) end, Procs).
+
+pinger([], [], true) ->
+ receive
+ {procs, Procs, ReportTo} ->
+ pinger(Procs, [], ReportTo)
+ end;
+pinger([], [], false) ->
+ receive {ping, From} -> From ! {pong, self()} end,
+ pinger([],[],false);
+pinger([], [], ReportTo) ->
+ ReportTo ! {done, self()},
+ pinger([],[],false);
+pinger([],[Po|Pos] = Pongers, ReportTo) ->
+ receive
+ {ping, From} ->
+ From ! {pong, self()},
+ pinger([], Pongers, ReportTo);
+ {pong, Po} ->
+ pinger([], Pos, ReportTo)
+ end;
+pinger([Pi|Pis], Pongers, ReportTo) ->
+ receive {ping, From} -> From ! {pong, self()}
+ after 0 -> ok
+ end,
+ Pi ! {ping, self()},
+ pinger(Pis, [Pi|Pongers], ReportTo).
+
+spawn_procs(N) when N =< 0 ->
+ [];
+spawn_procs(N) ->
+ [spawn_link(fun () -> pinger([], [], true) end) | spawn_procs(N-1)].
+
+send_procs([], Msg) ->
+ Msg;
+send_procs([P|Ps], Msg) ->
+ P ! Msg,
+ send_procs(Ps, Msg).
+
+receive_msgs([]) ->
+ ok;
+receive_msgs([M|Ms]) ->
+ receive
+ M ->
+ receive_msgs(Ms)
+ end.