RFR: 7164841: Improvements to the GC log file rotation

[Thomas Schatzl]

Hi Yumin,

On Wed, 2013-09-11 at 15:45 -0700, Yumin Qi wrote:
> Thomas,
> 
>    Attached are two files, on is script file for running and the other 
> is the output result.
>    With this flag
> 
> ExecuteInternalVMTests
> 
> on, the run only print out so much, and did not contine to do rest of 
> the test. Think it is right.

  sorry for being unclear: the request has been to add new tests to the
internal VM tests, not only run them. The method to replace the %p/%t
markers would make them an ideal candidate for such testing.

E.g. have a method that compares output of that function with some known
values.

However I did not think it through completely, as the values of %p/%t
are dependent on external circumstances, and it is maybe not worth to
add infrastructure to allow fake values (well, one could extract the
generation of these values out, and pass them to the function under
test).

I.e.  change make_log_name()

to this signature:

make_log_name_internal(const char* log_name, const char*
force_directory, const char* datetime, int pid) {

  ... use datetime, pid in the code instead of retrieving them here...
}

make_log_name(const char* log_name, const char* force_directory) {
  char tms[32];
  get_datetime_string(tms, sizeof(tms);

  make_log_name_internal(log_name, force_directory, tms,
os::current_process_id());
}

then you could easily write tests like:

  char* fixed_time = "1980-20-....";
  char* result;

  result = make_log_name_internal("somename%p", false, fixed_time, 200);
  if (strncmp(result, "somename200") != 0) { // error out }
  free result

  [... more tests...]

and so on. I am not sure how you did the testing while developing, but
the effort would probably only be a matter of converting them to this
format.

Thomas