1 files changed, 60 insertions, 0 deletions
diff --git a/dom/media/ipc/ShmemRecycleAllocator.h b/dom/media/ipc/ShmemRecycleAllocator.h
new file mode 100644
index 0000000000..7207e27014
--- /dev/null
+++ b/dom/media/ipc/ShmemRecycleAllocator.h
@@ -0,0 +1,60 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef include_dom_media_ipc_ShmemRecycleAllocator_h
+#define include_dom_media_ipc_ShmemRecycleAllocator_h
+
+#include "mozilla/ShmemPool.h"
+
+namespace mozilla {
+
+template <class T>
+class ShmemRecycleAllocator {
+ public:
+  explicit ShmemRecycleAllocator(T* aActor)
+      : mActor(aActor), mPool(1, ShmemPool::PoolType::DynamicPool) {}
+  ShmemBuffer AllocateBuffer(size_t aSize,
+                             ShmemPool::AllocationPolicy aPolicy =
+                                 ShmemPool::AllocationPolicy::Unsafe) {
+    ShmemBuffer buffer = mPool.Get(mActor, aSize, aPolicy);
+    if (!buffer.Valid()) {
+      return buffer;
+    }
+    MOZ_DIAGNOSTIC_ASSERT(aSize <= buffer.Get().Size<uint8_t>());
+    mUsedShmems.AppendElement(buffer.Get());
+    mNeedCleanup = true;
+    return buffer;
+  }
+
+  void ReleaseBuffer(ShmemBuffer&& aBuffer) { mPool.Put(std::move(aBuffer)); }
+
+  void ReleaseAllBuffers() {
+    for (auto&& mem : mUsedShmems) {
+      ReleaseBuffer(ShmemBuffer(mem.Get()));
+    }
+    mUsedShmems.Clear();
+  }
+
+  void CleanupShmemRecycleAllocator() {
+    ReleaseAllBuffers();
+    mPool.Cleanup(mActor);
+    mNeedCleanup = false;
+  }
+
+  ~ShmemRecycleAllocator() {
+    MOZ_DIAGNOSTIC_ASSERT(mUsedShmems.IsEmpty() && !mNeedCleanup,
+                          "Shmems not all deallocated");
+  }
+
+ private:
+  T* const mActor;
+  ShmemPool mPool;
+  AutoTArray<ShmemBuffer, 4> mUsedShmems;
+  bool mNeedCleanup = false;
+};
+
+}  // namespace mozilla
+
+#endif  // include_dom_media_ipc_ShmemRecycleAllocator_h