Reland of "[heap] Tracer: Handle incremental marking scopes"

src/heap/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 796 matching lines @@
     AbortTransitionArrays();
     AbortCompaction();
     if (heap_->UsingEmbedderHeapTracer()) {
       heap_->mark_compact_collector()->embedder_heap_tracer()->AbortTracing();
     }
     was_marked_incrementally_ = false;
   }
 
   if (!was_marked_incrementally_) {
     if (heap_->UsingEmbedderHeapTracer()) {
+      TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPER_PROLOGUE);
       heap_->mark_compact_collector()->embedder_heap_tracer()->TracePrologue();
     }
   }
 
   if (UsingEmbedderHeapTracer()) {
     embedder_heap_tracer()->EnterFinalPause();
   }
 
   // Don't start compaction if we are in the middle of incremental
   // marking cycle. We did not collect any slots.
@@ skipping 1247 matching lines @@
 }
 
 // Mark all objects reachable (transitively) from objects on the marking
 // stack including references only considered in the atomic marking pause.
 void MarkCompactCollector::ProcessEphemeralMarking(
     ObjectVisitor* visitor, bool only_process_harmony_weak_collections) {
   DCHECK(marking_deque_.IsEmpty() && !marking_deque_.overflowed());
   bool work_to_do = true;
   while (work_to_do) {
     if (UsingEmbedderHeapTracer()) {
+      TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPER_TRACING);
       RegisterWrappersWithEmbedderHeapTracer();
       embedder_heap_tracer()->AdvanceTracing(
           0, EmbedderHeapTracer::AdvanceTracingActions(
                  EmbedderHeapTracer::ForceCompletionAction::FORCE_COMPLETION));
     }
     if (!only_process_harmony_weak_collections) {
+      TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_OBJECT_GROUPING);
       isolate()->global_handles()->IterateObjectGroups(
           visitor, &IsUnmarkedHeapObjectWithHeap);
       MarkImplicitRefGroups(&MarkCompactMarkingVisitor::MarkObject);
     }
     ProcessWeakCollections();
     work_to_do = !marking_deque_.IsEmpty();
     ProcessMarkingDeque();
   }
 }
 
@@ skipping 258 matching lines @@
 
     // Repeat Harmony weak maps marking to mark unmarked objects reachable from
     // the weak roots we just marked as pending destruction.
     //
     // We only process harmony collections, as all object groups have been fully
     // processed and no weakly reachable node can discover new objects groups.
     {
       TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WEAK_CLOSURE_HARMONY);
       ProcessEphemeralMarking(&root_visitor, true);
       if (UsingEmbedderHeapTracer()) {
+        TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPER_EPILOGUE);
         embedder_heap_tracer()->TraceEpilogue();
       }
     }
   }
 
   if (FLAG_print_cumulative_gc_stat) {
     heap_->tracer()->AddMarkingTime(heap_->MonotonicallyIncreasingTimeInMs() -
                                     start_time);
   }
 }
@@ skipping 1651 matching lines @@
       // The target is always in old space, we don't have to record the slot in
       // the old-to-new remembered set.
       DCHECK(!heap()->InNewSpace(target));
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8