test/hotspot/gtest/utilities/test_waitBarrier.cpp

*** 47,70 ****
      _wrt_start->signal();
      int vv, tag;
      // Similar to how a JavaThread would stop in a safepoint.
      while (!_exit) {
        // Load the published tag.
!       tag = OrderAccess::load_acquire(&wait_tag);
        // Publish the tag this thread is going to wait for.
!       OrderAccess::release_store(&_on_barrier, tag);
        if (_on_barrier == 0) {
          SpinPause();
          continue;
        }
        OrderAccess::storeload(); // Loads in WB must not float up.
        // Wait until we are woken.
        _wait_barrier->wait(tag);
        // Verify that we do not see an invalid value.
!       vv = OrderAccess::load_acquire(&valid_value);
        ASSERT_EQ((vv & 0x1), 0);
!       OrderAccess::release_store(&_on_barrier, 0);
      }
    }
  };
  
  template <typename WaitBarrierImpl>
--- 47,70 ----
      _wrt_start->signal();
      int vv, tag;
      // Similar to how a JavaThread would stop in a safepoint.
      while (!_exit) {
        // Load the published tag.
!       tag = Atomic::load_acquire(&wait_tag);
        // Publish the tag this thread is going to wait for.
!       Atomic::release_store(&_on_barrier, tag);
        if (_on_barrier == 0) {
          SpinPause();
          continue;
        }
        OrderAccess::storeload(); // Loads in WB must not float up.
        // Wait until we are woken.
        _wait_barrier->wait(tag);
        // Verify that we do not see an invalid value.
!       vv = Atomic::load_acquire(&valid_value);
        ASSERT_EQ((vv & 0x1), 0);
!       Atomic::release_store(&_on_barrier, 0);
      }
    }
  };
  
  template <typename WaitBarrierImpl>
*** 102,128 ****
      // Similar to how the VM thread would use a WaitBarrier in a safepoint.
      while (stop_ms > os::javaTimeMillis()) {
        // Arm next tag.
        wb.arm(next_tag);
        // Publish tag.
!       OrderAccess::release_store_fence(&wait_tag, next_tag);
  
        // Wait until threads picked up new tag.
        while (reader1->_on_barrier != wait_tag ||
               reader2->_on_barrier != wait_tag ||
               reader3->_on_barrier != wait_tag ||
               reader4->_on_barrier != wait_tag) {
          SpinPause();
        }
  
        // Set an invalid value.
!       OrderAccess::release_store(&valid_value, valid_value + 1); // odd
        os::naked_yield();
        // Set a valid value.
!       OrderAccess::release_store(&valid_value, valid_value + 1); // even
        // Publish inactive tag.
!       OrderAccess::release_store_fence(&wait_tag, 0); // Stores in WB must not float up.
        wb.disarm();
  
        // Wait until threads done valid_value verification.
        while (reader1->_on_barrier != 0 ||
               reader2->_on_barrier != 0 ||
--- 102,128 ----
      // Similar to how the VM thread would use a WaitBarrier in a safepoint.
      while (stop_ms > os::javaTimeMillis()) {
        // Arm next tag.
        wb.arm(next_tag);
        // Publish tag.
!       Atomic::release_store_fence(&wait_tag, next_tag);
  
        // Wait until threads picked up new tag.
        while (reader1->_on_barrier != wait_tag ||
               reader2->_on_barrier != wait_tag ||
               reader3->_on_barrier != wait_tag ||
               reader4->_on_barrier != wait_tag) {
          SpinPause();
        }
  
        // Set an invalid value.
!       Atomic::release_store(&valid_value, valid_value + 1); // odd
        os::naked_yield();
        // Set a valid value.
!       Atomic::release_store(&valid_value, valid_value + 1); // even
        // Publish inactive tag.
!       Atomic::release_store_fence(&wait_tag, 0); // Stores in WB must not float up.
        wb.disarm();
  
        // Wait until threads done valid_value verification.
        while (reader1->_on_barrier != 0 ||
               reader2->_on_barrier != 0 ||