diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/tools/doc/src/lcnt_chapter.xml | 26 | ||||
| -rw-r--r-- | lib/tools/test/lcnt_SUITE.erl | 85 |
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 38bebd1fac..1981d66117 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. |