Reland "[heap] Move pointers updating to ItemParallelJob"

Furthermore avoid lock-step between pointer updating phases as they
should execute in parallel without synchronization restrictions.

This reverts commit bc6adb86.

Bug: chromium:726040
Change-Id: I1713d4333f0ce1604ff51c02461f3ef91e4bdaed
Reviewed-on: https://chromium-review.googlesource.com/521062Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45657}

src/heap/gc-tracer.cc

@@ -538,10 +538,8 @@ void GCTracer::PrintNVP() const {
           "evacuate=%.2f "
           "evacuate.copy=%.2f "
           "evacuate.update_pointers=%.2f "
-          "evacuate.update_pointers.to_new=%.2f "
-          "evacuate.update_pointers.to_new.tospace=%.2f "
-          "evacuate.update_pointers.to_new.roots=%.2f "
-          "evacuate.update_pointers.to_new.old=%.2f "
+          "evacuate.update_pointers.to_new_roots=%.2f "
+          "evacuate.update_pointers.slots=%.2f "
           "update_marking_deque=%.2f "
           "reset_liveness=%.2f\n",
           duration, spent_in_mutator, "mmc", current_.reduce_memory,
@@ -558,12 +556,9 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::MINOR_MC_EVACUATE],
           current_.scopes[Scope::MINOR_MC_EVACUATE_COPY],
           current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS],
-          current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW],
-          current_
-              .scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_TOSPACE],
           current_
               .scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS],
-          current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_OLD],
+          current_.scopes[Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_SLOTS],
           current_.scopes[Scope::MINOR_MC_MARKING_DEQUE],
           current_.scopes[Scope::MINOR_MC_RESET_LIVENESS]);
       break;
@@ -598,8 +593,8 @@ void GCTracer::PrintNVP() const {
           "evacuate.epilogue=%.1f "
           "evacuate.rebalance=%.1f "
           "evacuate.update_pointers=%.1f "
-          "evacuate.update_pointers.to_evacuated=%.1f "
-          "evacuate.update_pointers.to_new=%.1f "
+          "evacuate.update_pointers.to_new_roots=%.1f "
+          "evacuate.update_pointers.slots=%.1f "
           "evacuate.update_pointers.weak=%.1f "
           "finish=%.1f "
           "mark=%.1f "
@@ -682,8 +677,8 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::MC_EVACUATE_EPILOGUE],
           current_.scopes[Scope::MC_EVACUATE_REBALANCE],
           current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS],
-          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_EVACUATED],
-          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_NEW],
+          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS],
+          current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_SLOTS],
           current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_WEAK],
           current_.scopes[Scope::MC_FINISH], current_.scopes[Scope::MC_MARK],
           current_.scopes[Scope::MC_MARK_FINISH_INCREMENTAL],

src/heap/gc-tracer.h

@@ -60,8 +60,8 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
   F(MC_EVACUATE_PROLOGUE)                           \
   F(MC_EVACUATE_REBALANCE)                          \
   F(MC_EVACUATE_UPDATE_POINTERS)                    \
-  F(MC_EVACUATE_UPDATE_POINTERS_TO_EVACUATED)         \
-  F(MC_EVACUATE_UPDATE_POINTERS_TO_NEW)               \
+  F(MC_EVACUATE_UPDATE_POINTERS_SLOTS)              \
+  F(MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS)       \
   F(MC_EVACUATE_UPDATE_POINTERS_WEAK)               \
   F(MC_FINISH)                                      \
   F(MC_MARK)                                        \
@@ -91,10 +91,8 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
   F(MINOR_MC_EVACUATE_PROLOGUE)                     \
   F(MINOR_MC_EVACUATE_REBALANCE)                    \
   F(MINOR_MC_EVACUATE_UPDATE_POINTERS)              \
-  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW)         \
+  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_SLOTS)        \
   F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_ROOTS) \
-  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_TOSPACE) \
-  F(MINOR_MC_EVACUATE_UPDATE_POINTERS_TO_NEW_OLD)     \
   F(MINOR_MC_EVACUATE_UPDATE_POINTERS_WEAK)         \
   F(MINOR_MC_MARK)                                  \
   F(MINOR_MC_MARK_GLOBAL_HANDLES)                   \

src/heap/mark-compact.h

@@ -22,6 +22,7 @@ namespace internal {
 // Forward declarations.
 class EvacuationJobTraits;
 class HeapObjectVisitor;
+class ItemParallelJob;
 class LocalWorkStealingMarkingDeque;
 class MarkCompactCollector;
 class MinorMarkCompactCollector;
@@ -276,9 +277,9 @@ class MarkCompactCollectorBase {
   // Returns whether this page should be moved according to heuristics.
   bool ShouldMovePage(Page* p, intptr_t live_bytes);
 
+  int CollectToSpaceUpdatingItems(ItemParallelJob* job);
   template <RememberedSetType type>
-  void UpdatePointersInParallel(base::Semaphore* semaphore);
-  void UpdateToSpacePointersInParallel(base::Semaphore* semaphore);
+  int CollectRememberedSetUpdatingItems(ItemParallelJob* job);
 
   int NumberOfParallelCompactionTasks(int pages);
   int NumberOfParallelPointerUpdateTasks(int pages, int slots);