1 files changed, 890 insertions, 0 deletions
diff --git a/dom/canvas/QueueParamTraits.h b/dom/canvas/QueueParamTraits.h
new file mode 100644
index 0000000000..fbb6bce6f8
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+++ b/dom/canvas/QueueParamTraits.h
@@ -0,0 +1,890 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=4 et :
+ */
+/* 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 _QUEUEPARAMTRAITS_H_
+#define _QUEUEPARAMTRAITS_H_ 1
+
+#include "ipc/EnumSerializer.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/IntegerRange.h"
+#include "mozilla/ipc/ProtocolUtils.h"
+#include "mozilla/ipc/SharedMemoryBasic.h"
+#include "mozilla/ipc/Shmem.h"
+#include "mozilla/Logging.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/TypeTraits.h"
+#include "nsExceptionHandler.h"
+#include "nsString.h"
+#include "WebGLTypes.h"
+
+namespace mozilla {
+namespace webgl {
+
+enum class QueueStatus {
+  // Operation was successful
+  kSuccess,
+  // The operation failed because the queue isn't ready for it.
+  // Either the queue is too full for an insert or too empty for a remove.
+  // The operation may succeed if retried.
+  kNotReady,
+  // The operation required more room than the queue supports.
+  // It should not be retried -- it will always fail.
+  kTooSmall,
+  // The operation failed for some reason that is unrecoverable.
+  // All values below this value indicate a fata error.
+  kFatalError,
+  // Fatal error: Internal processing ran out of memory.  This is likely e.g.
+  // during de-serialization.
+  kOOMError,
+};
+
+inline bool IsSuccess(QueueStatus status) {
+  return status == QueueStatus::kSuccess;
+}
+
+inline bool operator!(const QueueStatus status) { return !IsSuccess(status); }
+
+template <typename T>
+struct RemoveCVR {
+  typedef typename std::remove_reference<typename std::remove_cv<T>::type>::type
+      Type;
+};
+
+inline size_t UsedBytes(size_t aQueueBufferSize, size_t aRead, size_t aWrite) {
+  return (aRead <= aWrite) ? aWrite - aRead
+                           : (aQueueBufferSize - aRead) + aWrite;
+}
+
+inline size_t FreeBytes(size_t aQueueBufferSize, size_t aRead, size_t aWrite) {
+  // Remember, queueSize is queueBufferSize-1
+  return (aQueueBufferSize - 1) - UsedBytes(aQueueBufferSize, aRead, aWrite);
+}
+
+template <typename T>
+struct IsTriviallySerializable
+    : public std::integral_constant<bool, std::is_arithmetic<T>::value &&
+                                              !std::is_same<T, bool>::value> {};
+
+/**
+ * QueueParamTraits provide the user with a way to implement PCQ argument
+ * (de)serialization.  It uses a PcqView, which permits the system to
+ * abandon all changes to the underlying PCQ if any operation fails.
+ *
+ * The transactional nature of PCQ operations make the ideal behavior a bit
+ * complex.  Since the PCQ has a fixed amount of memory available to it,
+ * TryInsert operations operations are expected to sometimes fail and be
+ * re-issued later.  We want these failures to be inexpensive.  The same
+ * goes for TryRemove, which fails when there isn't enough data in
+ * the queue yet for them to complete.
+ *
+ * Their expected interface is:
+ *
+ * template<> struct QueueParamTraits<typename RemoveCVR<Arg>::Type> {
+ *   // Write data from aArg into the PCQ.
+ *   static QueueStatus Write(ProducerView& aProducerView, const Arg& aArg)
+ *   {...};
+ *
+ *   // Read data from the PCQ into aArg, or just skip the data if aArg is null.
+ *   static QueueStatus Read(ConsumerView& aConsumerView, Arg* aArg) {...}
+ * };
+ */
+template <typename Arg>
+struct QueueParamTraits;  // Todo: s/QueueParamTraits/SizedParamTraits/
+
+/**
+ * The marshaller handles all data insertion into the queue.
+ */
+class Marshaller {
+ public:
+  static QueueStatus WriteObject(uint8_t* aQueue, size_t aQueueBufferSize,
+                                 size_t aRead, size_t* aWrite, const void* aArg,
+                                 size_t aArgLength) {
+    const uint8_t* buf = reinterpret_cast<const uint8_t*>(aArg);
+    if (FreeBytes(aQueueBufferSize, aRead, *aWrite) < aArgLength) {
+      return QueueStatus::kNotReady;
+    }
+
+    if (*aWrite + aArgLength <= aQueueBufferSize) {
+      memcpy(aQueue + *aWrite, buf, aArgLength);
+    } else {
+      size_t firstLen = aQueueBufferSize - *aWrite;
+      memcpy(aQueue + *aWrite, buf, firstLen);
+      memcpy(aQueue, &buf[firstLen], aArgLength - firstLen);
+    }
+    *aWrite = (*aWrite + aArgLength) % aQueueBufferSize;
+    return QueueStatus::kSuccess;
+  }
+
+  static QueueStatus ReadObject(const uint8_t* aQueue, size_t aQueueBufferSize,
+                                size_t* aRead, size_t aWrite, void* aArg,
+                                size_t aArgLength) {
+    if (UsedBytes(aQueueBufferSize, *aRead, aWrite) < aArgLength) {
+      return QueueStatus::kNotReady;
+    }
+
+    if (aArg) {
+      uint8_t* buf = reinterpret_cast<uint8_t*>(aArg);
+      if (*aRead + aArgLength <= aQueueBufferSize) {
+        memcpy(buf, aQueue + *aRead, aArgLength);
+      } else {
+        size_t firstLen = aQueueBufferSize - *aRead;
+        memcpy(buf, aQueue + *aRead, firstLen);
+        memcpy(&buf[firstLen], aQueue, aArgLength - firstLen);
+      }
+    }
+
+    *aRead = (*aRead + aArgLength) % aQueueBufferSize;
+    return QueueStatus::kSuccess;
+  }
+};
+
+template <typename T>
+inline Range<T> AsRange(T* const begin, T* const end) {
+  const auto size = MaybeAs<size_t>(end - begin);
+  MOZ_RELEASE_ASSERT(size);
+  return {begin, *size};
+}
+
+/**
+ * Used to give QueueParamTraits a way to write to the Producer without
+ * actually altering it, in case the transaction fails.
+ * THis object maintains the error state of the transaction and
+ * discards commands issued after an error is encountered.
+ */
+template <typename _Producer>
+class ProducerView {
+ public:
+  using Producer = _Producer;
+
+  ProducerView(Producer* aProducer, size_t aRead, size_t* aWrite)
+      : mProducer(aProducer),
+        mRead(aRead),
+        mWrite(aWrite),
+        mStatus(QueueStatus::kSuccess) {}
+
+  template <typename T>
+  QueueStatus WriteFromRange(const Range<const T>& src) {
+    if (!mStatus) return mStatus;
+    mProducer->WriteFromRange(src);
+    return mStatus;
+  }
+  /**
+   * Copy bytes from aBuffer to the producer if there is enough room.
+   * aBufferSize must not be 0.
+   */
+  template <typename T>
+  inline QueueStatus Write(const T* begin, const T* end) {
+    MOZ_RELEASE_ASSERT(begin <= end);
+    if (!mStatus) return mStatus;
+    WriteFromRange(AsRange(begin, end));
+    return mStatus;
+  }
+
+  template <typename T>
+  inline QueueStatus WritePod(const T& in) {
+    static_assert(std::is_trivially_copyable_v<T>);
+    const auto begin = reinterpret_cast<const uint8_t*>(&in);
+    return Write(begin, begin + sizeof(T));
+  }
+
+  /**
+   * Serialize aArg using Arg's QueueParamTraits.
+   */
+  template <typename Arg>
+  QueueStatus WriteParam(const Arg& aArg) {
+    return mozilla::webgl::QueueParamTraits<
+        typename RemoveCVR<Arg>::Type>::Write(*this, aArg);
+  }
+
+  QueueStatus GetStatus() { return mStatus; }
+
+ private:
+  Producer* mProducer;
+  size_t mRead;
+  size_t* mWrite;
+  QueueStatus mStatus;
+};
+
+/**
+ * Used to give QueueParamTraits a way to read from the Consumer without
+ * actually altering it, in case the transaction fails.
+ */
+template <typename _Consumer>
+class ConsumerView {
+ public:
+  using Consumer = _Consumer;
+
+  ConsumerView(Consumer* aConsumer, size_t* aRead, size_t aWrite)
+      : mConsumer(aConsumer),
+        mRead(aRead),
+        mWrite(aWrite),
+        mStatus(QueueStatus::kSuccess) {}
+
+  /**
+   * Read bytes from the consumer if there is enough data.  aBuffer may
+   * be null (in which case the data is skipped)
+   */
+  template <typename T>
+  inline QueueStatus Read(T* const destBegin, T* const destEnd) {
+    MOZ_ASSERT(destBegin);
+    MOZ_RELEASE_ASSERT(destBegin <= destEnd);
+    if (!mStatus) return mStatus;
+
+    const auto dest = AsRange(destBegin, destEnd);
+    const auto view = ReadRange<T>(dest.length());
+    if (!view) return mStatus;
+    const auto byteSize = ByteSize(dest);
+    if (byteSize) {
+      memcpy(dest.begin().get(), view->begin().get(), byteSize);
+    }
+    return mStatus;
+  }
+
+  /// Return a view wrapping the shmem.
+  template <typename T>
+  inline Maybe<Range<const T>> ReadRange(const size_t elemCount) {
+    if (!mStatus) return {};
+    const auto view = mConsumer->template ReadRange<T>(elemCount);
+    if (!view) {
+      mStatus = QueueStatus::kTooSmall;
+    }
+    return view;
+  }
+
+  template <typename T>
+  inline QueueStatus ReadPod(T* out) {
+    static_assert(std::is_trivially_copyable_v<T>);
+    const auto begin = reinterpret_cast<uint8_t*>(out);
+    return Read(begin, begin + sizeof(T));
+  }
+
+  /**
+   * Deserialize aArg using Arg's QueueParamTraits.
+   * If the return value is not Success then aArg is not changed.
+   */
+  template <typename Arg>
+  QueueStatus ReadParam(Arg* aArg) {
+    MOZ_ASSERT(aArg);
+    return mozilla::webgl::QueueParamTraits<std::remove_cv_t<Arg>>::Read(*this,
+                                                                         aArg);
+  }
+
+  QueueStatus GetStatus() { return mStatus; }
+
+ private:
+  Consumer* mConsumer;
+  size_t* mRead;
+  size_t mWrite;
+  QueueStatus mStatus;
+};
+
+// ---------------------------------------------------------------
+
+/**
+ * True for types that can be (de)serialized by memcpy.
+ */
+template <typename Arg>
+struct QueueParamTraits {
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView, const Arg& aArg) {
+    static_assert(mozilla::webgl::template IsTriviallySerializable<Arg>::value,
+                  "No QueueParamTraits specialization was found for this type "
+                  "and it does not satisfy IsTriviallySerializable.");
+    // Write self as binary
+    const auto begin = &aArg;
+    return aProducerView.Write(begin, begin + 1);
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, Arg* aArg) {
+    static_assert(mozilla::webgl::template IsTriviallySerializable<Arg>::value,
+                  "No QueueParamTraits specialization was found for this type "
+                  "and it does not satisfy IsTriviallySerializable.");
+    // Read self as binary
+    return aConsumerView.Read(aArg, aArg + 1);
+  }
+};
+
+// ---------------------------------------------------------------
+
+template <>
+struct QueueParamTraits<bool> {
+  using ParamType = bool;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    uint8_t temp = aArg ? 1 : 0;
+    return aProducerView.WriteParam(temp);
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    uint8_t temp;
+    if (IsSuccess(aConsumerView.ReadParam(&temp))) {
+      MOZ_ASSERT(temp == 1 || temp == 0);
+      *aArg = temp ? true : false;
+    }
+    return aConsumerView.GetStatus();
+  }
+};
+
+// ---------------------------------------------------------------
+
+// Adapted from IPC::EnumSerializer, this class safely handles enum values,
+// validating that they are in range using the same EnumValidators as IPDL
+// (namely ContiguousEnumValidator and ContiguousEnumValidatorInclusive).
+template <typename E, typename EnumValidator>
+struct EnumSerializer {
+  typedef E ParamType;
+  typedef typename std::underlying_type<E>::type DataType;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aValue) {
+    MOZ_RELEASE_ASSERT(EnumValidator::IsLegalValue(aValue));
+    return aProducerView.WriteParam(DataType(aValue));
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aResult) {
+    DataType value;
+    if (!aConsumerView.ReadParam(&value)) {
+      CrashReporter::AnnotateCrashReport(
+          CrashReporter::Annotation::IPCReadErrorReason, "Bad iter"_ns);
+      return aConsumerView.GetStatus();
+    }
+    if (!EnumValidator::IsLegalValue(ParamType(value))) {
+      CrashReporter::AnnotateCrashReport(
+          CrashReporter::Annotation::IPCReadErrorReason, "Illegal value"_ns);
+      return QueueStatus::kFatalError;
+    }
+
+    *aResult = ParamType(value);
+    return QueueStatus::kSuccess;
+  }
+};
+
+using IPC::ContiguousEnumValidator;
+using IPC::ContiguousEnumValidatorInclusive;
+
+template <typename E, E MinLegal, E HighBound>
+struct ContiguousEnumSerializer
+    : EnumSerializer<E, ContiguousEnumValidator<E, MinLegal, HighBound>> {};
+
+template <typename E, E MinLegal, E MaxLegal>
+struct ContiguousEnumSerializerInclusive
+    : EnumSerializer<E,
+                     ContiguousEnumValidatorInclusive<E, MinLegal, MaxLegal>> {
+};
+
+// ---------------------------------------------------------------
+
+template <>
+struct QueueParamTraits<QueueStatus>
+    : public ContiguousEnumSerializerInclusive<
+          QueueStatus, QueueStatus::kSuccess, QueueStatus::kOOMError> {};
+
+// ---------------------------------------------------------------
+
+template <>
+struct QueueParamTraits<webgl::TexUnpackBlobDesc> {
+  using ParamType = webgl::TexUnpackBlobDesc;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& view, const ParamType& in) {
+    MOZ_RELEASE_ASSERT(!in.image);
+    const bool isDataSurf = bool(in.dataSurf);
+    if (!view.WriteParam(in.imageTarget) || !view.WriteParam(in.size) ||
+        !view.WriteParam(in.srcAlphaType) || !view.WriteParam(in.unpacking) ||
+        !view.WriteParam(in.cpuData) || !view.WriteParam(in.pboOffset) ||
+        !view.WriteParam(in.imageSize) || !view.WriteParam(in.sd) ||
+        !view.WriteParam(isDataSurf)) {
+      return view.GetStatus();
+    }
+    if (isDataSurf) {
+      const auto& surf = in.dataSurf;
+      gfx::DataSourceSurface::ScopedMap map(surf, gfx::DataSourceSurface::READ);
+      if (!map.IsMapped()) {
+        return QueueStatus::kOOMError;
+      }
+      const auto& surfSize = surf->GetSize();
+      const auto stride = *MaybeAs<size_t>(map.GetStride());
+      if (!view.WriteParam(surfSize) || !view.WriteParam(surf->GetFormat()) ||
+          !view.WriteParam(stride)) {
+        return view.GetStatus();
+      }
+
+      const size_t dataSize = stride * surfSize.height;
+      const auto& begin = map.GetData();
+      if (!view.Write(begin, begin + dataSize)) {
+        return view.GetStatus();
+      }
+    }
+    return QueueStatus::kSuccess;
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& view, ParamType* const out) {
+    bool isDataSurf;
+    if (!view.ReadParam(&out->imageTarget) || !view.ReadParam(&out->size) ||
+        !view.ReadParam(&out->srcAlphaType) ||
+        !view.ReadParam(&out->unpacking) || !view.ReadParam(&out->cpuData) ||
+        !view.ReadParam(&out->pboOffset) || !view.ReadParam(&out->imageSize) ||
+        !view.ReadParam(&out->sd) || !view.ReadParam(&isDataSurf)) {
+      return view.GetStatus();
+    }
+    if (isDataSurf) {
+      gfx::IntSize surfSize;
+      gfx::SurfaceFormat format;
+      size_t stride;
+      if (!view.ReadParam(&surfSize) || !view.ReadParam(&format) ||
+          !view.ReadParam(&stride)) {
+        return view.GetStatus();
+      }
+      auto& surf = out->dataSurf;
+      surf = gfx::Factory::CreateDataSourceSurfaceWithStride(surfSize, format,
+                                                             stride, true);
+      if (!surf) {
+        return QueueStatus::kOOMError;
+      }
+
+      gfx::DataSourceSurface::ScopedMap map(surf,
+                                            gfx::DataSourceSurface::WRITE);
+      if (!map.IsMapped()) {
+        return QueueStatus::kOOMError;
+      }
+      const size_t dataSize = stride * surfSize.height;
+      const auto& begin = map.GetData();
+      if (!view.Read(begin, begin + dataSize)) {
+        return view.GetStatus();
+      }
+    }
+    return QueueStatus::kSuccess;
+  }
+};
+
+// ---------------------------------------------------------------
+
+template <>
+struct QueueParamTraits<nsACString> {
+  using ParamType = nsACString;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    if ((!aProducerView.WriteParam(aArg.IsVoid())) || aArg.IsVoid()) {
+      return aProducerView.GetStatus();
+    }
+
+    uint32_t len = aArg.Length();
+    if ((!aProducerView.WriteParam(len)) || (len == 0)) {
+      return aProducerView.GetStatus();
+    }
+
+    return aProducerView.Write(aArg.BeginReading(), len);
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    bool isVoid = false;
+    if (!IsSuccess(aConsumerView.ReadParam(&isVoid))) {
+      return aConsumerView.GetStatus();
+    }
+    aArg->SetIsVoid(isVoid);
+    if (isVoid) {
+      return QueueStatus::kSuccess;
+    }
+
+    uint32_t len = 0;
+    if (!IsSuccess(aConsumerView.ReadParam(&len))) {
+      return aConsumerView.GetStatus();
+    }
+
+    if (len == 0) {
+      *aArg = "";
+      return QueueStatus::kSuccess;
+    }
+
+    char* buf = new char[len + 1];
+    if (!buf) {
+      return QueueStatus::kOOMError;
+    }
+    if (!IsSuccess(aConsumerView.Read(buf, len))) {
+      return aConsumerView.GetStatus();
+    }
+    buf[len] = '\0';
+    aArg->Adopt(buf, len);
+    return QueueStatus::kSuccess;
+  }
+};
+
+template <>
+struct QueueParamTraits<nsAString> {
+  using ParamType = nsAString;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    if ((!aProducerView.WriteParam(aArg.IsVoid())) || (aArg.IsVoid())) {
+      return aProducerView.GetStatus();
+    }
+    // DLP: No idea if this includes null terminator
+    uint32_t len = aArg.Length();
+    if ((!aProducerView.WriteParam(len)) || (len == 0)) {
+      return aProducerView.GetStatus();
+    }
+    constexpr const uint32_t sizeofchar = sizeof(typename ParamType::char_type);
+    return aProducerView.Write(aArg.BeginReading(), len * sizeofchar);
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    bool isVoid = false;
+    if (!aConsumerView.ReadParam(&isVoid)) {
+      return aConsumerView.GetStatus();
+    }
+    aArg->SetIsVoid(isVoid);
+    if (isVoid) {
+      return QueueStatus::kSuccess;
+    }
+
+    // DLP: No idea if this includes null terminator
+    uint32_t len = 0;
+    if (!aConsumerView.ReadParam(&len)) {
+      return aConsumerView.GetStatus();
+    }
+
+    if (len == 0) {
+      *aArg = nsString();
+      return QueueStatus::kSuccess;
+    }
+
+    uint32_t sizeofchar = sizeof(typename ParamType::char_type);
+    typename ParamType::char_type* buf = nullptr;
+    buf = static_cast<typename ParamType::char_type*>(
+        malloc((len + 1) * sizeofchar));
+    if (!buf) {
+      return QueueStatus::kOOMError;
+    }
+
+    if (!aConsumerView.Read(buf, len * sizeofchar)) {
+      return aConsumerView.GetStatus();
+    }
+
+    buf[len] = L'\0';
+    aArg->Adopt(buf, len);
+    return QueueStatus::kSuccess;
+  }
+};
+
+template <>
+struct QueueParamTraits<nsCString> : public QueueParamTraits<nsACString> {
+  using ParamType = nsCString;
+};
+
+template <>
+struct QueueParamTraits<nsString> : public QueueParamTraits<nsAString> {
+  using ParamType = nsString;
+};
+
+// ---------------------------------------------------------------
+
+template <typename NSTArrayType,
+          bool =
+              IsTriviallySerializable<typename NSTArrayType::elem_type>::value>
+struct NSArrayQueueParamTraits;
+
+// For ElementTypes that are !IsTriviallySerializable
+template <typename _ElementType>
+struct NSArrayQueueParamTraits<nsTArray<_ElementType>, false> {
+  using ElementType = _ElementType;
+  using ParamType = nsTArray<ElementType>;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    aProducerView.WriteParam(aArg.Length());
+    for (auto& elt : aArg) {
+      aProducerView.WriteParam(elt);
+    }
+    return aProducerView.GetStatus();
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    size_t arrayLen;
+    if (!aConsumerView.ReadParam(&arrayLen)) {
+      return aConsumerView.GetStatus();
+    }
+
+    if (!aArg->AppendElements(arrayLen, fallible)) {
+      return QueueStatus::kOOMError;
+    }
+
+    for (auto i : IntegerRange(arrayLen)) {
+      ElementType& elt = aArg->ElementAt(i);
+      aConsumerView.ReadParam(elt);
+    }
+    return aConsumerView.GetStatus();
+  }
+};
+
+// For ElementTypes that are IsTriviallySerializable
+template <typename _ElementType>
+struct NSArrayQueueParamTraits<nsTArray<_ElementType>, true> {
+  using ElementType = _ElementType;
+  using ParamType = nsTArray<ElementType>;
+
+  // TODO: Are there alignment issues?
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    size_t arrayLen = aArg.Length();
+    aProducerView.WriteParam(arrayLen);
+    return aProducerView.Write(&aArg[0], aArg.Length() * sizeof(ElementType));
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    size_t arrayLen;
+    if (!aConsumerView.ReadParam(&arrayLen)) {
+      return aConsumerView.GetStatus();
+    }
+
+    if (!aArg->AppendElements(arrayLen, fallible)) {
+      return QueueStatus::kOOMError;
+    }
+
+    return aConsumerView.Read(aArg->Elements(), arrayLen * sizeof(ElementType));
+  }
+};
+
+template <typename ElementType>
+struct QueueParamTraits<nsTArray<ElementType>>
+    : public NSArrayQueueParamTraits<nsTArray<ElementType>> {
+  using ParamType = nsTArray<ElementType>;
+};
+
+// ---------------------------------------------------------------
+
+template <typename ArrayType,
+          bool =
+              IsTriviallySerializable<typename ArrayType::ElementType>::value>
+struct ArrayQueueParamTraits;
+
+// For ElementTypes that are !IsTriviallySerializable
+template <typename _ElementType, size_t Length>
+struct ArrayQueueParamTraits<Array<_ElementType, Length>, false> {
+  using ElementType = _ElementType;
+  using ParamType = Array<ElementType, Length>;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    for (const auto& elt : aArg) {
+      aProducerView.WriteParam(elt);
+    }
+    return aProducerView.GetStatus();
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    for (auto& elt : *aArg) {
+      aConsumerView.ReadParam(elt);
+    }
+    return aConsumerView.GetStatus();
+  }
+};
+
+// For ElementTypes that are IsTriviallySerializable
+template <typename _ElementType, size_t Length>
+struct ArrayQueueParamTraits<Array<_ElementType, Length>, true> {
+  using ElementType = _ElementType;
+  using ParamType = Array<ElementType, Length>;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    return aProducerView.Write(aArg.begin(), sizeof(ElementType[Length]));
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    return aConsumerView.Read(aArg->begin(), sizeof(ElementType[Length]));
+  }
+};
+
+template <typename ElementType, size_t Length>
+struct QueueParamTraits<Array<ElementType, Length>>
+    : public ArrayQueueParamTraits<Array<ElementType, Length>> {
+  using ParamType = Array<ElementType, Length>;
+};
+
+// ---------------------------------------------------------------
+
+template <typename ElementType>
+struct QueueParamTraits<Maybe<ElementType>> {
+  using ParamType = Maybe<ElementType>;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    aProducerView.WriteParam(static_cast<bool>(aArg));
+    return aArg ? aProducerView.WriteParam(aArg.ref())
+                : aProducerView.GetStatus();
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    bool isSome;
+    if (!aConsumerView.ReadParam(&isSome)) {
+      return aConsumerView.GetStatus();
+    }
+
+    if (!isSome) {
+      aArg->reset();
+      return QueueStatus::kSuccess;
+    }
+
+    aArg->emplace();
+    return aConsumerView.ReadParam(aArg->ptr());
+  }
+};
+
+// ---------------------------------------------------------------
+
+// Maybe<Variant> needs special behavior since Variant is not default
+// constructable.  The Variant's first type must be default constructible.
+template <typename T, typename... Ts>
+struct QueueParamTraits<Maybe<Variant<T, Ts...>>> {
+  using ParamType = Maybe<Variant<T, Ts...>>;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    aProducerView.WriteParam(aArg.mIsSome);
+    return (aArg.mIsSome) ? aProducerView.WriteParam(aArg.ref())
+                          : aProducerView.GetStatus();
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    bool isSome;
+    if (!aConsumerView.ReadParam(&isSome)) {
+      return aConsumerView.GetStatus();
+    }
+
+    if (!isSome) {
+      aArg->reset();
+      return QueueStatus::kSuccess;
+    }
+
+    aArg->emplace(VariantType<T>());
+    return aConsumerView.ReadParam(aArg->ptr());
+  }
+};
+
+// ---------------------------------------------------------------
+
+template <typename TypeA, typename TypeB>
+struct QueueParamTraits<std::pair<TypeA, TypeB>> {
+  using ParamType = std::pair<TypeA, TypeB>;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    aProducerView.WriteParam(aArg.first());
+    return aProducerView.WriteParam(aArg.second());
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    aConsumerView.ReadParam(aArg->first());
+    return aConsumerView.ReadParam(aArg->second());
+  }
+};
+
+// ---------------------------------------------------------------
+
+template <typename T>
+struct QueueParamTraits<UniquePtr<T>> {
+  using ParamType = UniquePtr<T>;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView,
+                           const ParamType& aArg) {
+    // TODO: Clean up move with PCQ
+    aProducerView.WriteParam(!static_cast<bool>(aArg));
+    if (aArg && aProducerView.WriteParam(*aArg.get())) {
+      const_cast<ParamType&>(aArg).reset();
+    }
+    return aProducerView.GetStatus();
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aArg) {
+    bool isNull;
+    if (!aConsumerView.ReadParam(&isNull)) {
+      return aConsumerView.GetStatus();
+    }
+    if (isNull) {
+      aArg->reset(nullptr);
+      return QueueStatus::kSuccess;
+    }
+
+    T* obj = nullptr;
+    obj = new T();
+    if (!obj) {
+      return QueueStatus::kOOMError;
+    }
+    aArg->reset(obj);
+    return aConsumerView.ReadParam(obj);
+  }
+};
+
+// ---------------------------------------------------------------
+
+template <>
+struct QueueParamTraits<mozilla::ipc::Shmem> {
+  using ParamType = mozilla::ipc::Shmem;
+
+  template <typename U>
+  static QueueStatus Write(ProducerView<U>& aProducerView, ParamType&& aParam) {
+    if (!aProducerView.WriteParam(
+            aParam.Id(mozilla::ipc::Shmem::PrivateIPDLCaller()))) {
+      return aProducerView.GetStatus();
+    }
+
+    aParam.RevokeRights(mozilla::ipc::Shmem::PrivateIPDLCaller());
+    aParam.forget(mozilla::ipc::Shmem::PrivateIPDLCaller());
+  }
+
+  template <typename U>
+  static QueueStatus Read(ConsumerView<U>& aConsumerView, ParamType* aResult) {
+    ParamType::id_t id;
+    if (!aConsumerView.ReadParam(&id)) {
+      return aConsumerView.GetStatus();
+    }
+
+    mozilla::ipc::Shmem::SharedMemory* rawmem =
+        aConsumerView.LookupSharedMemory(id);
+    if (!rawmem) {
+      return QueueStatus::kFatalError;
+    }
+
+    *aResult = mozilla::ipc::Shmem(mozilla::ipc::Shmem::PrivateIPDLCaller(),
+                                   rawmem, id);
+    return QueueStatus::kSuccess;
+  }
+};
+
+}  // namespace webgl
+}  // namespace mozilla
+
+#endif  // _QUEUEPARAMTRAITS_H_