// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/heap/array-buffer-collector.h"

#include "src/base/template-utils.h"
#include "src/heap/array-buffer-tracker.h"
#include "src/heap/gc-tracer.h"
#include "src/heap/heap-inl.h"

namespace v8 {
namespace internal {

void ArrayBufferCollector::AddGarbageAllocations(
    std::vector<JSArrayBuffer::Allocation> allocations) {
  base::LockGuard<base::Mutex> guard(&allocations_mutex_);
  allocations_.push_back(std::move(allocations));
}

void ArrayBufferCollector::FreeAllocations() {
  base::LockGuard<base::Mutex> guard(&allocations_mutex_);
  for (const std::vector<JSArrayBuffer::Allocation>& allocations :
       allocations_) {
    for (JSArrayBuffer::Allocation alloc : allocations) {
      JSArrayBuffer::FreeBackingStore(heap_->isolate(), alloc);
    }
  }
  allocations_.clear();
}

class ArrayBufferCollector::FreeingTask final : public CancelableTask {
 public:
  explicit FreeingTask(Heap* heap)
      : CancelableTask(heap->isolate()), heap_(heap) {}

  virtual ~FreeingTask() {}

 private:
  void RunInternal() final {
    TRACE_BACKGROUND_GC(
        heap_->tracer(),
        GCTracer::BackgroundScope::BACKGROUND_ARRAY_BUFFER_FREE);
    heap_->array_buffer_collector()->FreeAllocations();
  }

  Heap* heap_;
};

void ArrayBufferCollector::FreeAllocationsOnBackgroundThread() {
  // TODO(wez): Remove backing-store from external memory accounting.
  heap_->account_external_memory_concurrently_freed();
  if (!heap_->IsTearingDown() && FLAG_concurrent_array_buffer_freeing) {
    V8::GetCurrentPlatform()->CallOnWorkerThread(
        base::make_unique<FreeingTask>(heap_));
  } else {
    // Fallback for when concurrency is disabled/restricted.
    FreeAllocations();
  }
}

}  // namespace internal
}  // namespace v8