[heap] Ensure Isolate::GetHeapStatistics uses space mutex

PagedSpace::CommittedPhysicalMemory() needs to use mutex when iterating
chunks due to concurrent allocations.

Also reorder sampling of memory statistics according to this order:

1) used memory
2) committed physical memory
3) committed memory

That way, used <= committed physical <= committed should hold.

Bug: v8:10315
Change-Id: Ie922ecc4846f724a09c71667a898bf74a8652220
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2390768
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69698}

src/api/api.cc

@@ -8543,21 +8543,34 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   i::Heap* heap = isolate->heap();
 
-  heap_statistics->total_heap_size_ = heap->CommittedMemory();
+  // The order of acquiring memory statistics is important here. We query in
+  // this order because of concurrent allocation: 1) used memory 2) comitted
+  // physical memory 3) committed memory. Therefore the condition used <=
+  // committed physical <= committed should hold.
+  heap_statistics->used_global_handles_size_ = heap->UsedGlobalHandlesSize();
+  heap_statistics->total_global_handles_size_ = heap->TotalGlobalHandlesSize();
+  DCHECK_LE(heap_statistics->used_global_handles_size_,
+            heap_statistics->total_global_handles_size_);
+
+  heap_statistics->used_heap_size_ = heap->SizeOfObjects();
   heap_statistics->total_physical_size_ = heap->CommittedPhysicalMemory();
+  heap_statistics->total_heap_size_ = heap->CommittedMemory();
+
   heap_statistics->total_available_size_ = heap->Available();
-  heap_statistics->used_heap_size_ = heap->SizeOfObjects();
-  heap_statistics->total_global_handles_size_ = heap->TotalGlobalHandlesSize();
-  heap_statistics->used_global_handles_size_ = heap->UsedGlobalHandlesSize();
 
   if (!i::ReadOnlyHeap::IsReadOnlySpaceShared()) {
     i::ReadOnlySpace* ro_space = heap->read_only_space();
-    heap_statistics->total_heap_size_ += ro_space->CommittedMemory();
+    heap_statistics->used_heap_size_ += ro_space->Size();
     heap_statistics->total_physical_size_ +=
         ro_space->CommittedPhysicalMemory();
-    heap_statistics->used_heap_size_ += ro_space->Size();
+    heap_statistics->total_heap_size_ += ro_space->CommittedMemory();
   }
 
+  // TODO(dinfuehr): Right now used <= committed physical does not hold. Fix
+  // this and add DCHECK.
+  DCHECK_LE(heap_statistics->used_heap_size_,
+            heap_statistics->total_heap_size_);
+
   heap_statistics->total_heap_size_executable_ =
       heap->CommittedMemoryExecutable();
   heap_statistics->heap_size_limit_ = heap->MaxReserved();

src/heap/paged-spaces.cc

@@ -200,6 +200,7 @@ void PagedSpace::MergeLocalSpace(LocalSpace* other) {
 size_t PagedSpace::CommittedPhysicalMemory() {
   if (!base::OS::HasLazyCommits()) return CommittedMemory();
   BasicMemoryChunk::UpdateHighWaterMark(allocation_info_.top());
+  base::MutexGuard guard(mutex());
   size_t size = 0;
   for (Page* page : *this) {
     size += page->CommittedPhysicalMemory();