83     _result = g1h->attempt_allocation_at_safepoint(_word_size,
  84                                                    false /* expect_null_cur_alloc_region */);
  85     if (_result != NULL) {
  86       // If we can successfully allocate before we actually do the
  87       // pause then we will consider this pause successful.
  88       _pause_succeeded = true;
  89       return;
  90     }
  91   }
  92 
  93   GCCauseSetter x(g1h, _gc_cause);
  94   if (_should_initiate_conc_mark) {
  95     // It's safer to read old_marking_cycles_completed() here, given
  96     // that noone else will be updating it concurrently. Since we'll
  97     // only need it if we're initiating a marking cycle, no point in
  98     // setting it earlier.
  99     _old_marking_cycles_completed_before = g1h->old_marking_cycles_completed();
 100 
 101     // At this point we are supposed to start a concurrent cycle. We
 102     // will do so if one is not already in progress.
 103     bool res = g1h->g1_policy()->force_initial_mark_if_outside_cycle(_gc_cause);
 104 
 105     // The above routine returns true if we were able to force the
 106     // next GC pause to be an initial mark; it returns false if a
 107     // marking cycle is already in progress.
 108     //
 109     // If a marking cycle is already in progress just return and skip the
 110     // pause below - if the reason for requesting this initial mark pause
 111     // was due to a System.gc() then the requesting thread should block in
 112     // doit_epilogue() until the marking cycle is complete.
 113     //
 114     // If this initial mark pause was requested as part of a humongous
 115     // allocation then we know that the marking cycle must just have
 116     // been started by another thread (possibly also allocating a humongous
 117     // object) as there was no active marking cycle when the requesting
 118     // thread checked before calling collect() in
 119     // attempt_allocation_humongous(). Retrying the GC, in this case,
 120     // will cause the requesting thread to spin inside collect() until the
 121     // just started marking cycle is complete - which may be a while. So
 122     // we do NOT retry the GC.
 123     if (!res) {

  83     _result = g1h->attempt_allocation_at_safepoint(_word_size,
  84                                                    false /* expect_null_cur_alloc_region */);
  85     if (_result != NULL) {
  86       // If we can successfully allocate before we actually do the
  87       // pause then we will consider this pause successful.
  88       _pause_succeeded = true;
  89       return;
  90     }
  91   }
  92 
  93   GCCauseSetter x(g1h, _gc_cause);
  94   if (_should_initiate_conc_mark) {
  95     // It's safer to read old_marking_cycles_completed() here, given
  96     // that noone else will be updating it concurrently. Since we'll
  97     // only need it if we're initiating a marking cycle, no point in
  98     // setting it earlier.
  99     _old_marking_cycles_completed_before = g1h->old_marking_cycles_completed();
 100 
 101     // At this point we are supposed to start a concurrent cycle. We
 102     // will do so if one is not already in progress.
 103     bool res = g1h->policy()->force_initial_mark_if_outside_cycle(_gc_cause);
 104 
 105     // The above routine returns true if we were able to force the
 106     // next GC pause to be an initial mark; it returns false if a
 107     // marking cycle is already in progress.
 108     //
 109     // If a marking cycle is already in progress just return and skip the
 110     // pause below - if the reason for requesting this initial mark pause
 111     // was due to a System.gc() then the requesting thread should block in
 112     // doit_epilogue() until the marking cycle is complete.
 113     //
 114     // If this initial mark pause was requested as part of a humongous
 115     // allocation then we know that the marking cycle must just have
 116     // been started by another thread (possibly also allocating a humongous
 117     // object) as there was no active marking cycle when the requesting
 118     // thread checked before calling collect() in
 119     // attempt_allocation_humongous(). Retrying the GC, in this case,
 120     // will cause the requesting thread to spin inside collect() until the
 121     // just started marking cycle is complete - which may be a while. So
 122     // we do NOT retry the GC.
 123     if (!res) {