Track peak Zone memory usage and report it via HeapStatistics

BUG=
R=ulan@chromium.org,verwaest@chromium.org

Review-Url: https://codereview.chromium.org/2153423002
Cr-Commit-Position: refs/heads/master@{#37824}

include/v8.h

@@ -5248,6 +5248,7 @@ class V8_EXPORT HeapStatistics {
   size_t used_heap_size() { return used_heap_size_; }
   size_t heap_size_limit() { return heap_size_limit_; }
   size_t malloced_memory() { return malloced_memory_; }
+  size_t peak_malloced_memory() { return peak_malloced_memory_; }
   size_t does_zap_garbage() { return does_zap_garbage_; }
 
  private:
@@ -5258,6 +5259,7 @@ class V8_EXPORT HeapStatistics {
   size_t used_heap_size_;
   size_t heap_size_limit_;
   size_t malloced_memory_;
+  size_t peak_malloced_memory_;
   bool does_zap_garbage_;
 
   friend class V8;

src/api.cc

@@ -5619,6 +5619,7 @@ HeapStatistics::HeapStatistics()
       used_heap_size_(0),
       heap_size_limit_(0),
       malloced_memory_(0),
+      peak_malloced_memory_(0),
       does_zap_garbage_(0) {}
 
 HeapSpaceStatistics::HeapSpaceStatistics(): space_name_(0),
@@ -7597,6 +7598,8 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   heap_statistics->heap_size_limit_ = heap->MaxReserved();
   heap_statistics->malloced_memory_ =
       isolate->allocator()->GetCurrentMemoryUsage();
+  heap_statistics->peak_malloced_memory_ =
+      isolate->allocator()->GetMaxMemoryUsage();
   heap_statistics->does_zap_garbage_ = heap->ShouldZapGarbage();
 }
 

src/base/accounting-allocator.cc

@@ -15,7 +15,14 @@ namespace base {
 
 void* AccountingAllocator::Allocate(size_t bytes) {
   void* memory = malloc(bytes);
-  if (memory) NoBarrier_AtomicIncrement(&current_memory_usage_, bytes);
+  if (memory) {
+    AtomicWord current =
+        NoBarrier_AtomicIncrement(&current_memory_usage_, bytes);
+    AtomicWord max = NoBarrier_Load(&max_memory_usage_);
+    while (current > max) {
+      max = NoBarrier_CompareAndSwap(&max_memory_usage_, max, current);
+    }
+  }
   return memory;
 }
 
@@ -29,5 +36,9 @@ size_t AccountingAllocator::GetCurrentMemoryUsage() const {
   return NoBarrier_Load(&current_memory_usage_);
 }
 
+size_t AccountingAllocator::GetMaxMemoryUsage() const {
+  return NoBarrier_Load(&max_memory_usage_);
+}
+
 }  // namespace base
 }  // namespace v8

src/base/accounting-allocator.h

@@ -21,9 +21,11 @@ class AccountingAllocator final {
   void Free(void* memory, size_t bytes);
 
   size_t GetCurrentMemoryUsage() const;
+  size_t GetMaxMemoryUsage() const;
 
  private:
   AtomicWord current_memory_usage_ = 0;
+  AtomicWord max_memory_usage_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(AccountingAllocator);
 };