src/share/vm/memory/referenceProcessor.cpp

rev 2869 : 7117303: VM uses non-monotonic time source and complains that it is non-monotonic
Summary: Replaces calls to os::javaTimeMillis(), which does not guarantee montonicity, in GC code to os::javaTimeNanos() with a suitable conversion factor. os::javaTimeNanos() mostly guarantees montonicity depending on the underlying OS implementation and, as a result, a better alternative. Changes in OS files are to make use of the newly defined constants in globalDefinitions.hpp.
Reviewed-by:

*** 41,51 ****
  void referenceProcessor_init() {
    ReferenceProcessor::init_statics();
  }
  
  void ReferenceProcessor::init_statics() {
!   jlong now = os::javaTimeMillis();
  
    // Initialize the soft ref timestamp clock.
    _soft_ref_timestamp_clock = now;
    // Also update the soft ref clock in j.l.r.SoftReference
    java_lang_ref_SoftReference::set_clock(_soft_ref_timestamp_clock);
--- 41,52 ----
  void referenceProcessor_init() {
    ReferenceProcessor::init_statics();
  }
  
  void ReferenceProcessor::init_statics() {
!   // os::javaTimeMillis() does not guarantee monotonicity.
!   jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
  
    // Initialize the soft ref timestamp clock.
    _soft_ref_timestamp_clock = now;
    // Also update the soft ref clock in j.l.r.SoftReference
    java_lang_ref_SoftReference::set_clock(_soft_ref_timestamp_clock);
*** 149,159 ****
  }
  
  void ReferenceProcessor::update_soft_ref_master_clock() {
    // Update (advance) the soft ref master clock field. This must be done
    // after processing the soft ref list.
!   jlong now = os::javaTimeMillis();
    jlong soft_ref_clock = java_lang_ref_SoftReference::clock();
    assert(soft_ref_clock == _soft_ref_timestamp_clock, "soft ref clocks out of sync");
  
    NOT_PRODUCT(
    if (now < _soft_ref_timestamp_clock) {
--- 150,162 ----
  }
  
  void ReferenceProcessor::update_soft_ref_master_clock() {
    // Update (advance) the soft ref master clock field. This must be done
    // after processing the soft ref list.
! 
!   // os::javaTimeMillis() does not guarantee monotonicity.
!   jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
    jlong soft_ref_clock = java_lang_ref_SoftReference::clock();
    assert(soft_ref_clock == _soft_ref_timestamp_clock, "soft ref clocks out of sync");
  
    NOT_PRODUCT(
    if (now < _soft_ref_timestamp_clock) {