1 files changed, 239 insertions, 0 deletions
diff --git a/gfx/layers/ipc/ISurfaceAllocator.cpp b/gfx/layers/ipc/ISurfaceAllocator.cpp
new file mode 100644
index 0000000000..bf38b22226
--- /dev/null
+++ b/gfx/layers/ipc/ISurfaceAllocator.cpp
@@ -0,0 +1,239 @@
+/* -*- 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/. */
+
+#include "ISurfaceAllocator.h"
+
+#include "mozilla/layers/ImageBridgeParent.h"  // for ImageBridgeParent
+#include "mozilla/layers/TextureHost.h"        // for TextureHost
+#include "mozilla/layers/TextureForwarder.h"
+#include "mozilla/layers/CompositableForwarder.h"
+
+namespace mozilla {
+namespace layers {
+
+NS_IMPL_ISUPPORTS(GfxMemoryImageReporter, nsIMemoryReporter)
+
+mozilla::Atomic<ptrdiff_t> GfxMemoryImageReporter::sAmount(0);
+
+/* static */
+uint32_t CompositableForwarder::GetMaxFileDescriptorsPerMessage() {
+#if defined(OS_POSIX)
+  static const uint32_t kMaxFileDescriptors =
+      FileDescriptorSet::MAX_DESCRIPTORS_PER_MESSAGE;
+#else
+  // default number that works everywhere else
+  static const uint32_t kMaxFileDescriptors = 250;
+#endif
+  return kMaxFileDescriptors;
+}
+
+mozilla::ipc::SharedMemory::SharedMemoryType OptimalShmemType() {
+  return ipc::SharedMemory::SharedMemoryType::TYPE_BASIC;
+}
+
+void HostIPCAllocator::SendPendingAsyncMessages() {
+  if (mPendingAsyncMessage.empty()) {
+    return;
+  }
+
+  // Some type of AsyncParentMessageData message could have
+  // one file descriptor (e.g. OpDeliverFence).
+  // A number of file descriptors per gecko ipc message have a limitation
+  // on OS_POSIX (MACOSX or LINUX).
+#if defined(OS_POSIX)
+  static const uint32_t kMaxMessageNumber =
+      FileDescriptorSet::MAX_DESCRIPTORS_PER_MESSAGE;
+#else
+  // default number that works everywhere else
+  static const uint32_t kMaxMessageNumber = 250;
+#endif
+
+  nsTArray<AsyncParentMessageData> messages;
+  messages.SetCapacity(mPendingAsyncMessage.size());
+  for (size_t i = 0; i < mPendingAsyncMessage.size(); i++) {
+    messages.AppendElement(mPendingAsyncMessage[i]);
+    // Limit maximum number of messages.
+    if (messages.Length() >= kMaxMessageNumber) {
+      SendAsyncMessage(messages);
+      // Initialize Messages.
+      messages.Clear();
+    }
+  }
+
+  if (messages.Length() > 0) {
+    SendAsyncMessage(messages);
+  }
+  mPendingAsyncMessage.clear();
+}
+
+// XXX - We should actually figure out the minimum shmem allocation size on
+// a certain platform and use that.
+const uint32_t sShmemPageSize = 4096;
+
+#ifdef DEBUG
+const uint32_t sSupportedBlockSize = 4;
+#endif
+
+FixedSizeSmallShmemSectionAllocator::FixedSizeSmallShmemSectionAllocator(
+    LayersIPCChannel* aShmProvider)
+    : mShmProvider(aShmProvider) {
+  MOZ_ASSERT(mShmProvider);
+}
+
+FixedSizeSmallShmemSectionAllocator::~FixedSizeSmallShmemSectionAllocator() {
+  ShrinkShmemSectionHeap();
+}
+
+bool FixedSizeSmallShmemSectionAllocator::IPCOpen() const {
+  return mShmProvider->IPCOpen();
+}
+
+bool FixedSizeSmallShmemSectionAllocator::AllocShmemSection(
+    uint32_t aSize, ShmemSection* aShmemSection) {
+  // For now we only support sizes of 4. If we want to support different sizes
+  // some more complicated bookkeeping should be added.
+  MOZ_ASSERT(aSize == sSupportedBlockSize);
+  MOZ_ASSERT(aShmemSection);
+
+  if (!IPCOpen()) {
+    gfxCriticalError() << "Attempt to allocate a ShmemSection after shutdown.";
+    return false;
+  }
+
+  uint32_t allocationSize = (aSize + sizeof(ShmemSectionHeapAllocation));
+
+  for (size_t i = 0; i < mUsedShmems.size(); i++) {
+    ShmemSectionHeapHeader* header =
+        mUsedShmems[i].get<ShmemSectionHeapHeader>();
+    if ((header->mAllocatedBlocks + 1) * allocationSize +
+            sizeof(ShmemSectionHeapHeader) <
+        sShmemPageSize) {
+      aShmemSection->shmem() = mUsedShmems[i];
+      MOZ_ASSERT(mUsedShmems[i].IsWritable());
+      break;
+    }
+  }
+
+  if (!aShmemSection->shmem().IsWritable()) {
+    ipc::Shmem tmp;
+    if (!mShmProvider->AllocUnsafeShmem(sShmemPageSize, OptimalShmemType(),
+                                        &tmp)) {
+      return false;
+    }
+
+    ShmemSectionHeapHeader* header = tmp.get<ShmemSectionHeapHeader>();
+    header->mTotalBlocks = 0;
+    header->mAllocatedBlocks = 0;
+
+    mUsedShmems.push_back(tmp);
+    aShmemSection->shmem() = tmp;
+  }
+
+  MOZ_ASSERT(aShmemSection->shmem().IsWritable());
+
+  ShmemSectionHeapHeader* header =
+      aShmemSection->shmem().get<ShmemSectionHeapHeader>();
+  uint8_t* heap =
+      aShmemSection->shmem().get<uint8_t>() + sizeof(ShmemSectionHeapHeader);
+
+  ShmemSectionHeapAllocation* allocHeader = nullptr;
+
+  if (header->mTotalBlocks > header->mAllocatedBlocks) {
+    // Search for the first available block.
+    for (size_t i = 0; i < header->mTotalBlocks; i++) {
+      allocHeader = reinterpret_cast<ShmemSectionHeapAllocation*>(heap);
+
+      if (allocHeader->mStatus == STATUS_FREED) {
+        break;
+      }
+      heap += allocationSize;
+    }
+    MOZ_ASSERT(allocHeader && allocHeader->mStatus == STATUS_FREED);
+    MOZ_ASSERT(allocHeader->mSize == sSupportedBlockSize);
+  } else {
+    heap += header->mTotalBlocks * allocationSize;
+
+    header->mTotalBlocks++;
+    allocHeader = reinterpret_cast<ShmemSectionHeapAllocation*>(heap);
+    allocHeader->mSize = aSize;
+  }
+
+  MOZ_ASSERT(allocHeader);
+  header->mAllocatedBlocks++;
+  allocHeader->mStatus = STATUS_ALLOCATED;
+
+  aShmemSection->size() = aSize;
+  aShmemSection->offset() = (heap + sizeof(ShmemSectionHeapAllocation)) -
+                            aShmemSection->shmem().get<uint8_t>();
+  ShrinkShmemSectionHeap();
+  return true;
+}
+
+void FixedSizeSmallShmemSectionAllocator::FreeShmemSection(
+    mozilla::layers::ShmemSection& aShmemSection) {
+  MOZ_ASSERT(aShmemSection.size() == sSupportedBlockSize);
+  MOZ_ASSERT(aShmemSection.offset() < sShmemPageSize - sSupportedBlockSize);
+
+  if (!aShmemSection.shmem().IsWritable()) {
+    return;
+  }
+
+  ShmemSectionHeapAllocation* allocHeader =
+      reinterpret_cast<ShmemSectionHeapAllocation*>(
+          aShmemSection.shmem().get<char>() + aShmemSection.offset() -
+          sizeof(ShmemSectionHeapAllocation));
+
+  MOZ_ASSERT(allocHeader->mSize == aShmemSection.size());
+
+  DebugOnly<bool> success =
+      allocHeader->mStatus.compareExchange(STATUS_ALLOCATED, STATUS_FREED);
+  // If this fails something really weird is going on.
+  MOZ_ASSERT(success);
+
+  ShmemSectionHeapHeader* header =
+      aShmemSection.shmem().get<ShmemSectionHeapHeader>();
+  header->mAllocatedBlocks--;
+}
+
+void FixedSizeSmallShmemSectionAllocator::DeallocShmemSection(
+    mozilla::layers::ShmemSection& aShmemSection) {
+  if (!IPCOpen()) {
+    gfxCriticalNote << "Attempt to dealloc a ShmemSections after shutdown.";
+    return;
+  }
+
+  FreeShmemSection(aShmemSection);
+  ShrinkShmemSectionHeap();
+}
+
+void FixedSizeSmallShmemSectionAllocator::ShrinkShmemSectionHeap() {
+  if (!IPCOpen()) {
+    mUsedShmems.clear();
+    return;
+  }
+
+  // The loop will terminate as we either increase i, or decrease size
+  // every time through.
+  size_t i = 0;
+  while (i < mUsedShmems.size()) {
+    ShmemSectionHeapHeader* header =
+        mUsedShmems[i].get<ShmemSectionHeapHeader>();
+    if (header->mAllocatedBlocks == 0) {
+      mShmProvider->DeallocShmem(mUsedShmems[i]);
+      // We don't particularly care about order, move the last one in the array
+      // to this position.
+      if (i < mUsedShmems.size() - 1) {
+        mUsedShmems[i] = mUsedShmems[mUsedShmems.size() - 1];
+      }
+      mUsedShmems.pop_back();
+    } else {
+      i++;
+    }
+  }
+}
+
+}  // namespace layers
+}  // namespace mozilla