1 files changed, 78 insertions, 0 deletions
diff --git a/dom/media/gmp/GMPSharedMemManager.h b/dom/media/gmp/GMPSharedMemManager.h
new file mode 100644
index 0000000000..1a04bdde14
--- /dev/null
+++ b/dom/media/gmp/GMPSharedMemManager.h
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 GMPSharedMemManager_h_
+#define GMPSharedMemManager_h_
+
+#include "mozilla/ipc/Shmem.h"
+#include "nsTArray.h"
+
+namespace mozilla::gmp {
+
+class GMPSharedMemManager;
+
+class GMPSharedMem {
+ public:
+  typedef enum {
+    kGMPFrameData = 0,
+    kGMPEncodedData,
+    kGMPNumTypes
+  } GMPMemoryClasses;
+
+  // This is a heuristic - max of 10 free in the Child pool, plus those
+  // in-use for the encoder and decoder at the given moment and not yet
+  // returned to the parent pool (which is not included).  If more than
+  // this are needed, we presume the client has either crashed or hung
+  // (perhaps temporarily).
+  static const uint32_t kGMPBufLimit = 40;
+
+  GMPSharedMem() {
+    for (size_t i = 0; i < sizeof(mGmpAllocated) / sizeof(mGmpAllocated[0]);
+         i++) {
+      mGmpAllocated[i] = 0;
+    }
+  }
+  virtual ~GMPSharedMem() = default;
+
+  // Parent and child impls will differ here
+  virtual void CheckThread() = 0;
+
+ protected:
+  friend class GMPSharedMemManager;
+
+  nsTArray<ipc::Shmem> mGmpFreelist[GMPSharedMem::kGMPNumTypes];
+  uint32_t mGmpAllocated[GMPSharedMem::kGMPNumTypes];
+};
+
+class GMPSharedMemManager {
+ public:
+  explicit GMPSharedMemManager(GMPSharedMem* aData) : mData(aData) {}
+  virtual ~GMPSharedMemManager() = default;
+
+  virtual bool MgrAllocShmem(GMPSharedMem::GMPMemoryClasses aClass,
+                             size_t aSize, ipc::Shmem* aMem);
+  virtual bool MgrDeallocShmem(GMPSharedMem::GMPMemoryClasses aClass,
+                               ipc::Shmem& aMem);
+
+  // So we can know if data is "piling up" for the plugin - I.e. it's hung or
+  // crashed
+  virtual uint32_t NumInUse(GMPSharedMem::GMPMemoryClasses aClass);
+
+  // These have to be implemented using the AllocShmem/etc provided by the
+  // IPDL-generated interfaces, so have the Parent/Child implement them.
+  virtual bool Alloc(size_t aSize, ipc::Shmem* aMem) = 0;
+  virtual void Dealloc(ipc::Shmem&& aMem) = 0;
+
+ private:
+  nsTArray<ipc::Shmem>& GetGmpFreelist(GMPSharedMem::GMPMemoryClasses aTypes) {
+    return mData->mGmpFreelist[aTypes];
+  }
+
+  GMPSharedMem* mData;
+};
+
+}  // namespace mozilla::gmp
+
+#endif  // GMPSharedMemManager_h_