Merge branch 'bjorn/stdlib/cuddle-with-tests'

* bjorn/stdlib/cuddle-with-tests:
  Eliminate deprecated now/0 used as timestamp
  Eliminate use of now/0 for creating a unique filename
  Eliminate use of deprecated now/0 for measuring time
  Eliminate use of deprecated now/0 for random number generation
  Speed up timer_simple_SUITE:timer_perf/1
  Speed up timer_SUITE
  Optimize gen_server_SUITE:hibernate/1
  Optimize gen_event_SUITE:hibernate/1
  Optimize gen_fsm_SUITE:hibernate/1
  Optimize unicode_SUITE:ex_binaries_errors* test cases
  Optimize unicode_SUITE:binaries_errors/1
  binary_module_SUITE: Remove unnecessary calls to the binref module
  Optimize binary_module:random_ref_comp/1
  Optimize io_proto_SUITE:unicode_options_gen/1

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).
 
 %% ------------------------------------------------------- %%