RFR 8130459(M): Add additional validation after heap creation

[Kim Barrett]

On Jul 23, 2015, at 8:53 PM, sangheon.kim <sangheon.kim at oracle.com> wrote:
> 
> Hi Kim,
> 
> Updated webrev includes:
> - Moved functions related to range/constraints from CommandLineFlags to CommandLineFlagConstraintList / CommandLineFlagRangeList.
> - 2 functions are changed to 'const'.
> - 2 typos.
> 
> webrev.04:
> http://cr.openjdk.java.net/~sangheki/8130459/webrev.04
> 
> Incremental:
> http://cr.openjdk.java.net/~sangheki/8130459/webrev.04_to_03

------------------------------------------------------------------------------
src/share/vm/runtime/commandLineFlagConstraintList.cpp
 343   // Skip if we already checked.
 344   if (type < _validating_type) {
 345     return true;
 346   }

That's not quite what I had in mind when I suggested the type should
be verified to be less than _validating_type.  I think it's a program
error for that test to fail, e.g. it should be checked with a
assert/guarantee (I would use guarantee).  For example, if we were to
(presumably unintentionally) perform constraint checking out of order
then the out of order check would simply not be performed - ever -
with the code above.

------------------------------------------------------------------------------ 
src/share/vm/runtime/thread.cpp
3333   bool constraint_result = CommandLineFlagConstraintList::check_constraints(CommandLineFlagConstraint::AfterErgo);
3334   Arguments::post_after_ergo_constraint_check(constraint_result);
3335   if (!constraint_result) {
3336     return JNI_EINVAL;
3337   }

Simpler would be

  if (!CommandLineFlagConstraintList::check_constraints(CommandLineFlagConstraint::AfterErgo)) {
    return JNI_EINVAL;
  }
  Arguments::post_after_ergo_constraint_check();

with associated change of post_after_ergo_constraint_check to
eliminate the unused(!) argument.

------------------------------------------------------------------------------