[heap] Expand new space in safepoint

Move expansion of the new space into the safepoint. Otherwise background
threads race with the main thread when accessing the new space capacity.
This will most likely also be required to allow the allocation of new
space objects from background threads.

Bug: v8:10315
Change-Id: Ia8ac0c9f582876b655eaf4e35082aeadfbdb830e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2235532Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68226}

src/heap/heap.cc

@@ -862,7 +862,6 @@ void Heap::GarbageCollectionPrologue() {
   } else {
     maximum_size_scavenges_ = 0;
   }
-  CheckNewSpaceExpansionCriteria();
   UpdateNewSpaceAllocationCounter();
   if (FLAG_track_retaining_path) {
     retainer_.clear();
@@ -872,6 +871,10 @@ void Heap::GarbageCollectionPrologue() {
   memory_allocator()->unmapper()->PrepareForGC();
 }
 
+void Heap::GarbageCollectionPrologueInSafepoint() {
+  CheckNewSpaceExpansionCriteria();
+}
+
 size_t Heap::SizeOfObjects() {
   size_t total = 0;
 
@@ -2091,6 +2094,8 @@ size_t Heap::PerformGarbageCollection(
 #endif
   tracer()->StartInSafepoint();
 
+  GarbageCollectionPrologueInSafepoint();
+
   EnsureFromSpaceIsCommitted();
 
   size_t start_young_generation_size =

src/heap/heap.h

@@ -1786,6 +1786,7 @@ class Heap {
   // Code that should be run before and after each GC.  Includes some
   // reporting/verification activities when compiled with DEBUG set.
   void GarbageCollectionPrologue();
+  void GarbageCollectionPrologueInSafepoint();
   void GarbageCollectionEpilogue();
   void GarbageCollectionEpilogueInSafepoint();