src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp

rev 7557 : 8060025: Object copy time regressions after JDK-8031323 and JDK-8057536
Summary: Evaluate and improve object copy time by micro-optimizations and splitting out slow and fast paths aggressively.
Reviewed-by:
Contributed-by: Tony Printezis <tprintezis@twitter.com>, Thomas Schatzl <thomas.schatzl@oracle.com>
rev 7559 : imported patch mikael-refactor-cset-state
rev 7560 : imported patch kim-review

*** 159,170 ****
  
  HeapWord* G1ParScanThreadState::allocate_in_next_plab(InCSetState const state,
                                                        InCSetState* dest,
                                                        size_t word_sz,
                                                        AllocationContext_t const context) {
!   assert(state.is_in_cset_or_humongous(), err_msg("Unexpected state: %u", state.value()));
!   assert(dest->is_in_cset_or_humongous(), err_msg("Unexpected dest: %u", dest->value()));
  
    // Right now we only have two types of regions (young / old) so
    // let's keep the logic here simple. We can generalize it when necessary.
    if (dest->is_young()) {
      HeapWord* const obj_ptr = _g1_par_allocator->allocate(InCSetState::Old,
--- 159,170 ----
  
  HeapWord* G1ParScanThreadState::allocate_in_next_plab(InCSetState const state,
                                                        InCSetState* dest,
                                                        size_t word_sz,
                                                        AllocationContext_t const context) {
!   assert(state.is_in_cset_or_humongous(), err_msg("Unexpected state: " CSETSTATE_FORMAT, state.value()));
!   assert(dest->is_in_cset_or_humongous(), err_msg("Unexpected dest: " CSETSTATE_FORMAT, dest->value()));
  
    // Right now we only have two types of regions (young / old) so
    // let's keep the logic here simple. We can generalize it when necessary.
    if (dest->is_young()) {
      HeapWord* const obj_ptr = _g1_par_allocator->allocate(InCSetState::Old,
*** 177,187 ****
      // any new ones) to avoid coming into this slow path.
      _tenuring_threshold = 0;
      dest->set_old();
      return obj_ptr;
    } else {
!     assert(dest->is_old(), err_msg("Unexpected dest: %u", dest->value()));
      // no other space to try.
      return NULL;
    }
  }
  
--- 177,187 ----
      // any new ones) to avoid coming into this slow path.
      _tenuring_threshold = 0;
      dest->set_old();
      return obj_ptr;
    } else {
!     assert(dest->is_old(), err_msg("Unexpected dest: " CSETSTATE_FORMAT, dest->value()));
      // no other space to try.
      return NULL;
    }
  }