Avoid verifying heap while sweeper is running.

runtime/vm/scavenger.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/scavenger.h"
 
 #include <algorithm>
 #include <map>
 #include <utility>
 
@@ skipping 779 matching lines @@
 
 
 void Scavenger::Scavenge(bool invoke_api_callbacks) {
   // Scavenging is not reentrant. Make sure that is the case.
   ASSERT(!scavenging_);
   scavenging_ = true;
   Isolate* isolate = heap_->isolate();
   PageSpace* page_space = heap_->old_space();
   NoHandleScope no_handles(isolate);
 
-  if (FLAG_verify_before_gc) {
+  // TODO(koda): Make verification more compatible with concurrent sweep.
+  if (FLAG_verify_before_gc && !FLAG_concurrent_sweep) {
     OS::PrintErr("Verifying before Scavenge...");
-    // TODO(koda): Check whether sweeper is actually running.
-    heap_->Verify(FLAG_concurrent_sweep ? kAllowMarked : kForbidMarked);
+    heap_->Verify(kForbidMarked);
     OS::PrintErr(" done.\n");
   }
 
   // Prepare for a scavenge.
   SpaceUsage usage_before = GetCurrentUsage();
   intptr_t promo_candidate_words =
       (survivor_end_ - FirstObjectStart()) / kWordSize;
   Prologue(isolate, invoke_api_callbacks);
   const bool prologue_weak_are_strong = !invoke_api_callbacks;
 
@@ skipping 16 matching lines @@
   // Scavenge finished. Run accounting and epilogue.
   int64_t end = OS::GetCurrentTimeMicros();
   heap_->RecordTime(kProcessToSpace, middle - start);
   heap_->RecordTime(kIterateWeaks, end - middle);
   stats_history_.Add(ScavengeStats(start, end,
                                    usage_before, GetCurrentUsage(),
                                    promo_candidate_words,
                                    visitor.bytes_promoted() >> kWordSizeLog2));
   Epilogue(isolate, &visitor, invoke_api_callbacks);
 
-  if (FLAG_verify_after_gc) {
+  // TODO(koda): Make verification more compatible with concurrent sweep.
+  if (FLAG_verify_after_gc && !FLAG_concurrent_sweep) {
     OS::PrintErr("Verifying after Scavenge...");
-    // TODO(koda): Check whether sweeper is actually running.
-    heap_->Verify(FLAG_concurrent_sweep ? kAllowMarked : kForbidMarked);
+    heap_->Verify(kForbidMarked);
     OS::PrintErr(" done.\n");
   }
 
   // Done scavenging. Reset the marker.
   ASSERT(scavenging_);
   scavenging_ = false;
 }
 
 
 void Scavenger::WriteProtect(bool read_only) {
@@ skipping 36 matching lines @@
 }
 
 
 void Scavenger::FreeExternal(intptr_t size) {
   ASSERT(size >= 0);
   external_size_ -= size;
   ASSERT(external_size_ >= 0);
 }
 
 }  // namespace dart