[heap] Allow LocalHeap on the main thread

This changes the safepoint scope to skip LocalHeap that is active
for the current thread to avoid deadlocking.

Bug: v8:10315
Change-Id: I45e80ae66d0dbbe768107aa9cf0603204c644d9f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2289983Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68769}

src/heap/safepoint.cc

@@ -23,17 +23,25 @@ void GlobalSafepoint::EnterSafepointScope() {
   if (!FLAG_local_heaps) return;
 
   if (++active_safepoint_scopes_ > 1) return;
+
   local_heaps_mutex_.Lock();
+  local_heap_of_this_thread_ = LocalHeap::Current();
 
   barrier_.Arm();
 
   for (LocalHeap* current = local_heaps_head_; current;
        current = current->next_) {
+    if (current == local_heap_of_this_thread_) {
+      continue;
+    }
     current->RequestSafepoint();
   }
 
   for (LocalHeap* current = local_heaps_head_; current;
        current = current->next_) {
+    if (current == local_heap_of_this_thread_) {
+      continue;
+    }
     current->state_mutex_.Lock();
 
     while (current->state_ == LocalHeap::ThreadState::Running) {
@@ -48,13 +56,19 @@ void GlobalSafepoint::LeaveSafepointScope() {
   DCHECK_GT(active_safepoint_scopes_, 0);
   if (--active_safepoint_scopes_ > 0) return;
 
+  DCHECK_EQ(local_heap_of_this_thread_, LocalHeap::Current());
+
   for (LocalHeap* current = local_heaps_head_; current;
        current = current->next_) {
+    if (current == local_heap_of_this_thread_) {
+      continue;
+    }
     current->state_mutex_.Unlock();
   }
 
   barrier_.Disarm();
 
+  local_heap_of_this_thread_ = nullptr;
   local_heaps_mutex_.Unlock();
 }
 

src/heap/safepoint.h

@@ -77,6 +77,8 @@ class GlobalSafepoint {
 
   int active_safepoint_scopes_;
 
+  LocalHeap* local_heap_of_this_thread_;
+
   friend class SafepointScope;
   friend class LocalHeap;
   friend class PersistentHandles;

test/cctest/heap/test-heap.cc

@@ -7141,6 +7141,22 @@ HEAP_TEST(GCDuringOffThreadMergeWithTransferHandle) {
   CHECK_EQ(transfer_handle.ToHandle()->length(), 10);
 }
 
+TEST(GarbageCollectionWithLocalHeap) {
+  FLAG_local_heaps = true;
+  ManualGCScope manual_gc_scope;
+  CcTest::InitializeVM();
+
+  Heap* heap = CcTest::i_isolate()->heap();
+
+  LocalHeap local_heap(heap);
+  CcTest::CollectGarbage(OLD_SPACE);
+  {
+    ParkedScope parked_scope(&local_heap);
+    CcTest::CollectGarbage(OLD_SPACE);
+  }
+  CcTest::CollectGarbage(OLD_SPACE);
+}
+
 }  // namespace heap
 }  // namespace internal
 }  // namespace v8

test/unittests/heap/safepoint-unittest.cc

@@ -138,5 +138,24 @@ TEST_F(SafepointTest, StopRunningThreads) {
   CHECK_EQ(safepoint_count, kRuns * kSafepoints);
 }
 
+TEST_F(SafepointTest, SkipLocalHeapOfThisThread) {
+  Heap* heap = i_isolate()->heap();
+  FLAG_local_heaps = true;
+  LocalHeap local_heap(heap);
+  {
+    SafepointScope scope(heap);
+    local_heap.Safepoint();
+  }
+  {
+    ParkedScope parked_scope(&local_heap);
+    SafepointScope scope(heap);
+    local_heap.Safepoint();
+  }
+  {
+    SafepointScope scope(heap);
+    local_heap.Safepoint();
+  }
+}
+
 }  // namespace internal
 }  // namespace v8