Implement Ashmen-based metadata buffer
Bug: 111976433
Test: atest buffer_hub_metadata-test
Change-Id: I27365ad5efd06a800438cd8c751471c1e40b0f80
diff --git a/libs/vr/libbufferhub/Android.bp b/libs/vr/libbufferhub/Android.bp
index edc9131..93091e3 100644
--- a/libs/vr/libbufferhub/Android.bp
+++ b/libs/vr/libbufferhub/Android.bp
@@ -15,6 +15,7 @@
sourceFiles = [
"buffer_hub_base.cpp",
"buffer_hub_client.cpp",
+ "buffer_hub_metadata.cpp",
"buffer_hub_rpc.cpp",
"consumer_buffer.cpp",
"detached_buffer.cpp",
@@ -69,3 +70,10 @@
name: "buffer_hub-test",
}
+cc_test {
+ srcs: ["buffer_hub_metadata-test.cpp"],
+ static_libs: ["libbufferhub"],
+ shared_libs: sharedLibraries,
+ header_libs: headerLibraries,
+ name: "buffer_hub_metadata-test",
+}
diff --git a/libs/vr/libbufferhub/buffer_hub_metadata-test.cpp b/libs/vr/libbufferhub/buffer_hub_metadata-test.cpp
new file mode 100644
index 0000000..8c1c01c
--- /dev/null
+++ b/libs/vr/libbufferhub/buffer_hub_metadata-test.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+#include <private/dvr/buffer_hub_metadata.h>
+
+using android::dvr::BufferHubDefs::IsBufferGained;
+
+namespace android {
+namespace dvr {
+
+constexpr size_t kEmptyUserMetadataSize = 0;
+
+class BufferHubMetadataTest : public ::testing::Test {};
+
+TEST_F(BufferHubMetadataTest, Create_UserMetdataSizeTooBig) {
+ BufferHubMetadata m1 =
+ BufferHubMetadata::Create(std::numeric_limits<uint32_t>::max());
+ EXPECT_FALSE(m1.IsValid());
+}
+
+TEST_F(BufferHubMetadataTest, Create_Success) {
+ BufferHubMetadata m1 = BufferHubMetadata::Create(kEmptyUserMetadataSize);
+ EXPECT_TRUE(m1.IsValid());
+ EXPECT_NE(m1.metadata_header(), nullptr);
+}
+
+TEST_F(BufferHubMetadataTest, Import_Success) {
+ BufferHubMetadata m1 = BufferHubMetadata::Create(kEmptyUserMetadataSize);
+ EXPECT_TRUE(m1.IsValid());
+ EXPECT_NE(m1.metadata_header(), nullptr);
+
+ pdx::LocalHandle h2 = m1.ashmem_handle().Duplicate();
+ EXPECT_TRUE(h2.IsValid());
+
+ BufferHubMetadata m2 = BufferHubMetadata::Import(std::move(h2));
+ EXPECT_FALSE(h2.IsValid());
+ EXPECT_TRUE(m1.IsValid());
+ BufferHubDefs::MetadataHeader* mh1 = m1.metadata_header();
+ EXPECT_NE(mh1, nullptr);
+
+ // TODO(b/111976433): Update this test once BufferHub state machine gets
+ // updated. In the old model, buffer starts in the gained state (i.e.
+ // valued 0). In the new model, buffer states in the released state.
+ EXPECT_TRUE(IsBufferGained(mh1->fence_state.load()));
+
+ EXPECT_TRUE(m2.IsValid());
+ BufferHubDefs::MetadataHeader* mh2 = m2.metadata_header();
+ EXPECT_NE(mh2, nullptr);
+
+ // TODO(b/111976433): Update this test once BufferHub state machine gets
+ // updated. In the old model, buffer starts in the gained state (i.e.
+ // valued 0). In the new model, buffer states in the released state.
+ EXPECT_TRUE(IsBufferGained(mh2->fence_state.load()));
+}
+
+TEST_F(BufferHubMetadataTest, MoveMetadataInvalidatesOldOne) {
+ BufferHubMetadata m1 = BufferHubMetadata::Create(sizeof(int));
+ EXPECT_TRUE(m1.IsValid());
+ EXPECT_NE(m1.metadata_header(), nullptr);
+ EXPECT_TRUE(m1.ashmem_handle().IsValid());
+ EXPECT_EQ(m1.user_metadata_size(), sizeof(int));
+
+ BufferHubMetadata m2 = std::move(m1);
+
+ // After the move, the metadata header (a raw pointer) should be reset in the
+ // older buffer.
+ EXPECT_EQ(m1.metadata_header(), nullptr);
+ EXPECT_NE(m2.metadata_header(), nullptr);
+
+ EXPECT_FALSE(m1.ashmem_handle().IsValid());
+ EXPECT_TRUE(m2.ashmem_handle().IsValid());
+
+ EXPECT_EQ(m1.user_metadata_size(), 0U);
+ EXPECT_EQ(m2.user_metadata_size(), sizeof(int));
+
+ BufferHubMetadata m3{std::move(m2)};
+
+ // After the move, the metadata header (a raw pointer) should be reset in the
+ // older buffer.
+ EXPECT_EQ(m2.metadata_header(), nullptr);
+ EXPECT_NE(m3.metadata_header(), nullptr);
+
+ EXPECT_FALSE(m2.ashmem_handle().IsValid());
+ EXPECT_TRUE(m3.ashmem_handle().IsValid());
+
+ EXPECT_EQ(m2.user_metadata_size(), 0U);
+ EXPECT_EQ(m3.user_metadata_size(), sizeof(int));
+}
+
+} // namespace dvr
+} // namespace android
diff --git a/libs/vr/libbufferhub/buffer_hub_metadata.cpp b/libs/vr/libbufferhub/buffer_hub_metadata.cpp
new file mode 100644
index 0000000..8243fc5
--- /dev/null
+++ b/libs/vr/libbufferhub/buffer_hub_metadata.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <sys/mman.h>
+
+#include <cutils/ashmem.h>
+#include <log/log.h>
+#include <private/dvr/buffer_hub_metadata.h>
+
+namespace android {
+namespace dvr {
+
+namespace {
+
+static const int kAshmemProt = PROT_READ | PROT_WRITE;
+
+} // namespace
+
+using BufferHubDefs::kMetadataHeaderSize;
+using BufferHubDefs::MetadataHeader;
+
+/* static */
+BufferHubMetadata BufferHubMetadata::Create(size_t user_metadata_size) {
+ // The size the of metadata buffer is used as the "width" parameter during
+ // allocation. Thus it cannot overflow uint32_t.
+ if (user_metadata_size >=
+ (std::numeric_limits<uint32_t>::max() - kMetadataHeaderSize)) {
+ ALOGE("BufferHubMetadata::Create: metadata size too big: %zu.",
+ user_metadata_size);
+ return {};
+ }
+
+ const size_t metadata_size = user_metadata_size + kMetadataHeaderSize;
+ int fd = ashmem_create_region(/*name=*/"BufferHubMetadata", metadata_size);
+ if (fd < 0) {
+ ALOGE("BufferHubMetadata::Create: failed to create ashmem region.");
+ return {};
+ }
+
+ // Hand over the ownership of the fd to a pdx::LocalHandle immediately after
+ // the successful return of ashmem_create_region. The ashmem_handle is going
+ // to own the fd and to prevent fd leaks during error handling.
+ pdx::LocalHandle ashmem_handle{fd};
+
+ if (ashmem_set_prot_region(ashmem_handle.Get(), kAshmemProt) != 0) {
+ ALOGE("BufferHubMetadata::Create: failed to set protect region.");
+ return {};
+ }
+
+ return BufferHubMetadata::Import(std::move(ashmem_handle));
+}
+
+/* static */
+BufferHubMetadata BufferHubMetadata::Import(pdx::LocalHandle ashmem_handle) {
+ if (!ashmem_valid(ashmem_handle.Get())) {
+ ALOGE("BufferHubMetadata::Import: invalid ashmem fd.");
+ return {};
+ }
+
+ size_t metadata_size = ashmem_get_size_region(ashmem_handle.Get());
+ size_t user_metadata_size = metadata_size - kMetadataHeaderSize;
+
+ auto metadata_header = static_cast<MetadataHeader*>(
+ mmap(nullptr, metadata_size, kAshmemProt, MAP_SHARED, ashmem_handle.Get(),
+ /*offset=*/0));
+ if (metadata_header == nullptr) {
+ ALOGE("BufferHubMetadata::Import: failed to map region.");
+ return {};
+ }
+
+ return BufferHubMetadata(user_metadata_size, std::move(ashmem_handle),
+ metadata_header);
+}
+
+BufferHubMetadata::BufferHubMetadata(size_t user_metadata_size,
+ pdx::LocalHandle ashmem_handle,
+ MetadataHeader* metadata_header)
+ : user_metadata_size_(user_metadata_size),
+ ashmem_handle_(std::move(ashmem_handle)),
+ metadata_header_(metadata_header) {}
+
+BufferHubMetadata::~BufferHubMetadata() {
+ if (metadata_header_ != nullptr) {
+ int ret = munmap(metadata_header_, metadata_size());
+ ALOGE_IF(ret != 0,
+ "BufferHubMetadata::~BufferHubMetadata: failed to unmap ashmem, "
+ "error=%d.",
+ errno);
+ metadata_header_ = nullptr;
+ }
+}
+
+} // namespace dvr
+} // namespace android
diff --git a/libs/vr/libbufferhub/include/private/dvr/buffer_hub_metadata.h b/libs/vr/libbufferhub/include/private/dvr/buffer_hub_metadata.h
new file mode 100644
index 0000000..980ade7
--- /dev/null
+++ b/libs/vr/libbufferhub/include/private/dvr/buffer_hub_metadata.h
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_DVR_BUFFER_HUB_METADATA_H_
+#define ANDROID_DVR_BUFFER_HUB_METADATA_H_
+
+#include <pdx/file_handle.h>
+#include <private/dvr/buffer_hub_defs.h>
+
+namespace android {
+namespace dvr {
+
+class BufferHubMetadata {
+ public:
+ // Creates a new BufferHubMetadata backed by an ashmem region.
+ //
+ // @param user_metadata_size Size in bytes of the user defined metadata. The
+ // entire metadata shared memory region to be allocated is the size of
+ // canonical BufferHubDefs::MetadataHeader plus user_metadata_size.
+ static BufferHubMetadata Create(size_t user_metadata_size);
+
+ // Imports an existing BufferHubMetadata from an ashmem FD.
+ //
+ // TODO(b/112338294): Refactor BufferHub to use Binder as its internal IPC
+ // backend instead of UDS.
+ //
+ // @param ashmem_handle Ashmem file handle representing an ashmem region.
+ static BufferHubMetadata Import(pdx::LocalHandle ashmem_handle);
+
+ BufferHubMetadata() = default;
+
+ BufferHubMetadata(BufferHubMetadata&& other) { *this = std::move(other); }
+
+ ~BufferHubMetadata();
+
+ BufferHubMetadata& operator=(BufferHubMetadata&& other) {
+ if (this != &other) {
+ user_metadata_size_ = other.user_metadata_size_;
+ other.user_metadata_size_ = 0;
+
+ ashmem_handle_ = std::move(other.ashmem_handle_);
+
+ // The old raw metadata_header_ pointer must be cleared, otherwise the
+ // destructor will automatically mummap() the shared memory.
+ metadata_header_ = other.metadata_header_;
+ other.metadata_header_ = nullptr;
+ }
+ return *this;
+ }
+
+ // Returns true if the metadata is valid, i.e. the metadata has a valid ashmem
+ // fd and the ashmem has been mapped into virtual address space.
+ bool IsValid() const {
+ return ashmem_handle_.IsValid() && metadata_header_ != nullptr;
+ }
+
+ size_t user_metadata_size() const { return user_metadata_size_; }
+ size_t metadata_size() const {
+ return user_metadata_size_ + BufferHubDefs::kMetadataHeaderSize;
+ }
+
+ const pdx::LocalHandle& ashmem_handle() const { return ashmem_handle_; }
+ BufferHubDefs::MetadataHeader* metadata_header() { return metadata_header_; }
+
+ private:
+ BufferHubMetadata(size_t user_metadata_size, pdx::LocalHandle ashmem_handle,
+ BufferHubDefs::MetadataHeader* metadata_header);
+
+ BufferHubMetadata(const BufferHubMetadata&) = delete;
+ void operator=(const BufferHubMetadata&) = delete;
+
+ size_t user_metadata_size_ = 0;
+ pdx::LocalHandle ashmem_handle_;
+ BufferHubDefs::MetadataHeader* metadata_header_ = nullptr;
+};
+
+} // namespace dvr
+} // namespace android
+
+#endif // ANDROID_DVR_BUFFER_HUB_METADATA_H_