diff options
Diffstat (limited to 'lib/stdlib/test/timer_SUITE.erl')
| -rw-r--r-- | lib/stdlib/test/timer_SUITE.erl | 43 |
1 files changed, 14 insertions, 29 deletions
diff --git a/lib/stdlib/test/timer_SUITE.erl b/lib/stdlib/test/timer_SUITE.erl index bea2b3fb2a..ae32d98807 100644 --- a/lib/stdlib/test/timer_SUITE.erl +++ b/lib/stdlib/test/timer_SUITE.erl @@ -25,14 +25,11 @@ -include_lib("test_server/include/test_server.hrl"). -%% Test suite for timer module. This is a really nasty test it runs a -%% lot of timeouts and then checks in the end if any of them was -%% trigggered too early or if any late timeouts was much too -%% late. What should be added is more testing of the interface -%% functions I guess. But I don't have time for that now. +%% Random test of the timer module. This is a really nasty test, as it +%% runs a lot of timeouts and then checks in the end if any of them +%% was triggered too early or if any late timeouts was much too late. %% -%% Expect it to run for at least 5-10 minutes! - +%% Running time on average is about 90 seconds. %% The main test case in this module is "do_big_test", which %% orders a large number of timeouts and measures how @@ -40,15 +37,8 @@ %% also a number of other concurrent processes running "nrev" at the same %% time. The result is analyzed afterwards by trying to check if the %% measured values are reasonable. It is hard to determine what is -%% reasonable on different machines therefore the test can sometimes -%% fail, even though the timer module is ok. I have checked against -%% previous versions of the timer module (which contained bugs) and it -%% seems it fails every time when running the buggy timer modules. -%% -%% The solution is to rewrite the test suite. Possible strategies for a -%% rewrite: smarter math on the measuring data, test cases with varying -%% amount of load. The test suite should also include tests that test the -%% interface of the timer module. +%% reasonable on different machines; therefore the test can sometimes +%% fail, even though the timer module is ok. suite() -> [{ct_hooks,[ts_install_cth]}]. @@ -89,10 +79,7 @@ report_result(Error) -> ?line test_server:fail(Error). big_test(N) -> C = start_collect(), system_time(), system_time(), system_time(), - A1 = element(2, erlang:now()), - A2 = A1 * 3, - A3 = element(3, erlang:now()), - random:seed(A1, A2, A3), + random:seed(erlang:timestamp()), random:uniform(100),random:uniform(100),random:uniform(100), big_loop(C, N, []), @@ -146,7 +133,7 @@ big_loop(C, N, Pids) -> %%Pids2=Pids1, %% wait a little while - timer:sleep(random:uniform(200)*10), + timer:sleep(random:uniform(200)*3), %% spawn zero, one or two nrev to get some load ;-/ Pids3 = start_nrev(Pids2, random:uniform(100)), @@ -166,14 +153,14 @@ start_nrev(Pids, _N) -> start_after_test(Pids, C, 1) -> - TO1 = random:uniform(100)*100, + TO1 = random:uniform(100)*47, [s_a_t(C, TO1)|Pids]; start_after_test(Pids, C, 2) -> - TO1 = random:uniform(100)*100, - TO2 = TO1 div random:uniform(3) + 200, + TO1 = random:uniform(100)*47, + TO2 = TO1 div random:uniform(3) + 101, [s_a_t(C, TO1),s_a_t(C, TO2)|Pids]; start_after_test(Pids, C, N) -> - TO1 = random:uniform(100)*100, + TO1 = random:uniform(100)*47, start_after_test([s_a_t(C, TO1)|Pids], C, N-1). s_a_t(C, TimeOut) -> @@ -199,7 +186,7 @@ a_t(C, TimeOut) -> maybe_start_i_test(Pids, C, 1) -> %% ok do it - TOI = random:uniform(100)*100, + TOI = random:uniform(53)*49, CountI = random:uniform(10) + 3, % at least 4 times [spawn_link(timer_SUITE, i_t, [C, TOI, CountI])|Pids]; maybe_start_i_test(Pids, _C, _) -> @@ -374,9 +361,7 @@ res_combine({error,Es}, [{error,E}|T]) -> system_time() -> - %%element(1, statistics(wall_clock)). - {M,S,U} = erlang:now(), - 1000000000 * M + 1000 * S + (U div 1000). + erlang:monotonic_time(milli_seconds). %% ------------------------------------------------------- %% |