Merge "Replace MemoryDealer in AudioFlinger" (9ffdb2d9) · Commits · e / os / android_frameworks_av

media/utils/include/mediautils/SharedMemoryAllocator.h

0 → 100644

+470 −0

Original line number	Diff line number	Diff line
		/*
		** Copyright 2022, 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.
		*/

		#pragma once

		#include <sys/stat.h>
		#include <sys/types.h>
		#include <unistd.h>

		#include <iomanip>
		#include <limits>
		#include <sstream>
		#include <string>
		#include <type_traits>
		#include <unordered_map>

		#include <binder/MemoryBase.h>
		#include <binder/MemoryHeapBase.h>
		#include <log/log_main.h>
		#include <utils/StrongPointer.h>

		namespace std {
		template <typename T>
		struct hash<::android::wp<T>> {
		size_t operator()(const ::android::wp<T>& x) const {
		return std::hash<const T*>()(x.unsafe_get());
		}
		};
		} // namespace std

		namespace android::mediautils {

		// Allocations represent owning handles to a region of shared memory (and thus
		// should not be copied in order to fulfill RAII).
		// To share ownership between multiple objects, a
		// ref-counting solution such as sp or shared ptr is appropriate, so the dtor
		// is called once for a particular block of memory.

		using AllocationType = ::android::sp<IMemory>;
		using WeakAllocationType = ::android::wp<IMemory>;

		namespace shared_allocator_impl {
		constexpr inline size_t roundup(size_t size, size_t pageSize) {
		LOG_ALWAYS_FATAL_IF(pageSize == 0 \|\| (pageSize & (pageSize - 1)) != 0,
		"Page size not multiple of 2");
		return ((size + pageSize - 1) & ~(pageSize - 1));
		}

		constexpr inline bool isHeapValid(const sp<IMemoryHeap>& heap) {
		return (heap && heap->getBase() &&
		heap->getBase() != MAP_FAILED); // TODO if not mapped locally
		}

		template <typename, typename = void>
		static constexpr bool has_deallocate_all = false;

		template <typename T>
		static constexpr bool has_deallocate_all<
		T, std::enable_if_t<std::is_same_v<decltype(std::declval<T>().deallocate_all()), void>,
		void>> = true;

		template <typename, typename = void>
		static constexpr bool has_owns = false;

		template <typename T>
		static constexpr bool
		has_owns<T, std::enable_if_t<std::is_same_v<decltype(std::declval<T>().owns(
		std::declval<const AllocationType>())),
		bool>,
		void>> = true;

		template <typename, typename = void>
		static constexpr bool has_dump = false;

		template <typename T>
		static constexpr bool has_dump<
		T,
		std::enable_if_t<std::is_same_v<decltype(std::declval<T>().dump()), std::string>, void>> =
		true;

		} // namespace shared_allocator_impl

		struct BasicAllocRequest {
		size_t size;
		};
		struct NamedAllocRequest : public BasicAllocRequest {
		std::string_view name;
		};

		// We are required to add a layer of indirection to hold a handle to the actual
		// block due to sp<> being unable to be created from an object once its
		// ref-count has dropped to zero. So, we have to hold onto an extra reference
		// here. We effectively want to know when the refCount of the object drops to
		// one, since we need to hold on to a reference to pass the object to interfaces
		// requiring an sp<>.
		// TODO is there some way to avoid paying this cost?
		template <typename Allocator>
		class ScopedAllocator;
		template <typename AllocationT, typename AllocatorHandleType>
		class ScopedAllocation : public BnMemory {
		public:
		template <typename T>
		friend class ScopedAllocator;
		ScopedAllocation(const AllocationT& allocation, const AllocatorHandleType& handle)
		: mAllocation(allocation), mHandle(handle) {}

		// Defer the implementation to the underlying mAllocation

		virtual sp<IMemoryHeap> getMemory(ssize_t* offset = nullptr,
		size_t* size = nullptr) const override {
		return mAllocation->getMemory(offset, size);
		}

		private:
		~ScopedAllocation() override { mHandle->deallocate(mAllocation); }

		const AllocationT mAllocation;
		const AllocatorHandleType mHandle;
		};

		// Allocations are only deallocated when going out of scope.
		// This should almost always be the outermost allocator.
		template <typename Allocator>
		class ScopedAllocator {
		public:
		using HandleT = std::shared_ptr<Allocator>;
		static constexpr size_t alignment() { return Allocator::alignment(); }

		explicit ScopedAllocator(const std::shared_ptr<Allocator>& allocator) : mAllocator(allocator) {}

		ScopedAllocator() : mAllocator(std::make_shared<Allocator>()) {}

		template <typename T>
		auto allocate(T&& request) {
		const auto allocation = mAllocator->allocate(std::forward<T>(request));
		if (!allocation) {
		return sp<ScopedAllocation<AllocationType, HandleT>>{};
		}
		return sp<ScopedAllocation<AllocationType, HandleT>>::make(allocation, mAllocator);
		}

		// Deallocate and deallocate_all are implicitly unsafe due to double
		// deallocates upon ScopedAllocation destruction. We can protect against this
		// efficiently with a gencount (for deallocate_all) or inefficiently (for
		// deallocate) but we choose not to
		//
		// Owns is only safe to pseudo-impl due to static cast reqs
		template <typename Enable = bool>
		auto owns(const sp<ScopedAllocation<AllocationType, HandleT>>& allocation) const
		-> std::enable_if_t<shared_allocator_impl::has_owns<Allocator>, Enable> {
		return mAllocator->owns(allocation->mAllocation);
		}

		template <typename Enable = std::string>
		auto dump() const -> std::enable_if_t<shared_allocator_impl::has_dump<Allocator>, Enable> {
		return mAllocator->dump();
		}

		private:
		// We store a shared pointer in order to ensure that the allocator outlives
		// allocations (which call back to become dereferenced).
		const HandleT mAllocator;
		};

		// A simple policy for PolicyAllocator which enforces a pool size and an allocation
		// size range.
		template <size_t PoolSize, size_t MinAllocSize = 0,
		size_t MaxAllocSize = std::numeric_limits<size_t>::max()>
		class SizePolicy {
		static_assert(PoolSize > 0);

		public:
		template <typename T>
		bool isValid(T&& request) const {
		static_assert(std::is_base_of_v<BasicAllocRequest, std::decay_t<T>>);
		return !(request.size > kMaxAllocSize \|\| request.size < kMinAllocSize \|\|
		mPoolSize + request.size > kPoolSize);
		}

		void allocated(const AllocationType& alloc) { mPoolSize += alloc->size(); }

		void deallocated(const AllocationType& alloc) { mPoolSize -= alloc->size(); }

		void deallocated_all() { mPoolSize = 0; }

		static constexpr size_t kPoolSize = PoolSize;
		static constexpr size_t kMinAllocSize = MinAllocSize;
		static constexpr size_t kMaxAllocSize = MaxAllocSize;

		private:
		size_t mPoolSize = 0;
		};

		// An allocator which accepts or rejects allocation requests by a parametrized
		// policy (which can carry state).
		template <typename Allocator, typename Policy>
		class PolicyAllocator {
		public:
		static constexpr size_t alignment() { return Allocator::alignment(); }

		PolicyAllocator(Allocator allocator, Policy policy)
		: mAllocator(allocator), mPolicy(std::move(policy)) {}

		// Default initialize the allocator and policy
		PolicyAllocator() = default;

		template <typename T>
		AllocationType allocate(T&& request) {
		static_assert(std::is_base_of_v<android::mediautils::BasicAllocRequest, std::decay_t<T>>);
		request.size = shared_allocator_impl::roundup(request.size, alignment());
		if (!mPolicy.isValid(request)) {
		return {};
		}
		AllocationType val = mAllocator.allocate(std::forward<T>(request));
		if (val == nullptr) return val;
		mPolicy.allocated(val);
		return val;
		}

		void deallocate(const AllocationType& allocation) {
		if (!allocation) return;
		mPolicy.deallocated(allocation);
		mAllocator.deallocate(allocation);
		}

		template <typename Enable = void>
		auto deallocate_all()
		-> std::enable_if_t<shared_allocator_impl::has_deallocate_all<Allocator>, Enable> {
		mAllocator.deallocate_all();
		mPolicy.deallocated_all();
		}

		template <typename Enable = bool>
		auto owns(const AllocationType& allocation) const
		-> std::enable_if_t<shared_allocator_impl::has_owns<Allocator>, Enable> {
		return mAllocator.owns(allocation);
		}

		template <typename Enable = std::string>
		auto dump() const -> std::enable_if_t<shared_allocator_impl::has_dump<Allocator>, Enable> {
		return mAllocator.dump();
		}

		private:
		[[no_unique_address]] Allocator mAllocator;
		[[no_unique_address]] Policy mPolicy;
		};

		// An allocator which keeps track of outstanding allocations for logging and
		// querying ownership.
		template <class Allocator>
		class SnoopingAllocator {
		public:
		struct AllocationData {
		std::string name;
		size_t allocation_number;
		};
		static constexpr size_t alignment() { return Allocator::alignment(); }

		SnoopingAllocator(Allocator allocator, std::string_view name)
		: mName(name), mAllocator(std::move(allocator)) {}

		explicit SnoopingAllocator(std::string_view name) : mName(name), mAllocator(Allocator{}) {}

		explicit SnoopingAllocator(Allocator allocator) : mAllocator(std::move(allocator)) {}

		// Default construct allocator and name
		SnoopingAllocator() = default;

		template <typename T>
		AllocationType allocate(T&& request) {
		static_assert(std::is_base_of_v<NamedAllocRequest, std::decay_t<T>>);
		AllocationType allocation = mAllocator.allocate(request);
		if (allocation)
		mAllocations.insert({WeakAllocationType{allocation},
		{std::string{request.name}, mAllocationNumber++}});
		return allocation;
		}

		void deallocate(const AllocationType& allocation) {
		if (!allocation) return;
		mAllocations.erase(WeakAllocationType{allocation});
		mAllocator.deallocate(allocation);
		}

		void deallocate_all() {
		if constexpr (shared_allocator_impl::has_deallocate_all<Allocator>) {
		mAllocator.deallocate_all();
		} else {
		for (auto& [mem, value] : mAllocations) {
		mAllocator.deallocate(mem);
		}
		}
		mAllocations.clear();
		}

		bool owns(const AllocationType& allocation) const {
		return (mAllocations.count(WeakAllocationType{allocation}) > 0);
		}

		std::string dump() const {
		std::ostringstream dump;
		dump << mName << " Allocator Dump:\n";
		dump << std::setw(8) << "HeapID" << std::setw(8) << "Size" << std::setw(8) << "Offset"
		<< std::setw(8) << "Order"
		<< " Name\n";
		for (auto& [mem, value] : mAllocations) {
		// TODO Imem size and offset
		const AllocationType handle = mem.promote();
		if (!handle) {
		dump << "Invalid memory lifetime!";
		continue;
		}
		const auto heap = handle->getMemory();
		dump << std::setw(8) << heap->getHeapID() << std::setw(8) << heap->getOffset()
		<< std::setw(8) << heap->getSize() << std::setw(8) << value.allocation_number
		<< " " << value.name << "\n";
		}
		return dump.str();
		}

		const std::unordered_map<WeakAllocationType, AllocationData>& getAllocations() {
		return mAllocations;
		}

		private:
		const std::string mName;
		[[no_unique_address]] Allocator mAllocator;
		// We don't take copies of the underlying information in an allocation,
		// rather, the allocation information is put on the heap and referenced via
		// a ref-counted solution. So, the address of the allocation information is
		// appropriate to hash. In order for this block to be freed, the underlying
		// allocation must be referenced by no one (thus deallocated).
		std::unordered_map<WeakAllocationType, AllocationData> mAllocations;
		// For debugging purposes, monotonic
		size_t mAllocationNumber = 0;
		};

		// An allocator which passes a failed allocation request to a backup allocator.
		template <class PrimaryAllocator, class SecondaryAllocator>
		class FallbackAllocator {
		public:
		static_assert(PrimaryAllocator::alignment() == SecondaryAllocator::alignment());
		static_assert(shared_allocator_impl::has_owns<PrimaryAllocator>);

		static constexpr size_t alignment() { return PrimaryAllocator::alignment(); }

		FallbackAllocator(const PrimaryAllocator& primary, const SecondaryAllocator& secondary)
		: mPrimary(primary), mSecondary(secondary) {}

		// Default construct primary and secondary allocator
		FallbackAllocator() = default;

		template <typename T>
		AllocationType allocate(T&& request) {
		AllocationType allocation = mPrimary.allocate(std::forward<T>(request));
		if (!allocation) allocation = mSecondary.allocate(std::forward<T>(request));
		return allocation;
		}

		void deallocate(const AllocationType& allocation) {
		if (!allocation) return;
		if (mPrimary.owns(allocation)) {
		mPrimary.deallocate(allocation);
		} else {
		mSecondary.deallocate(allocation);
		}
		}

		template <typename Enable = void>
		auto deallocate_all() -> std::enable_if_t<
		shared_allocator_impl::has_deallocate_all<PrimaryAllocator> &&
		shared_allocator_impl::has_deallocate_all<SecondaryAllocator>,
		Enable> {
		mPrimary.deallocate_all();
		mSecondary.deallocate_all();
		}

		template <typename Enable = bool>
		auto owns(const AllocationType& allocation) const
		-> std::enable_if_t<shared_allocator_impl::has_owns<SecondaryAllocator>, Enable> {
		return mPrimary.owns(allocation) \|\| mSecondary.owns(allocation);
		}

		template <typename Enable = std::string>
		auto dump() const
		-> std::enable_if_t<shared_allocator_impl::has_dump<PrimaryAllocator> &&
		shared_allocator_impl::has_dump<SecondaryAllocator>,
		Enable> {
		return std::string("Primary: \n") + mPrimary.dump() + std::string("Secondary: \n") +
		mSecondary.dump();
		}

		private:
		[[no_unique_address]] PrimaryAllocator mPrimary;
		[[no_unique_address]] SecondaryAllocator mSecondary;
		};

		// An allocator which is backed by a shared_ptr to an allocator, so multiple
		// allocators can share the same backing allocator (and thus the same state).
		template <typename Allocator>
		class IndirectAllocator {
		public:
		static constexpr size_t alignment() { return Allocator::alignment(); }

		explicit IndirectAllocator(const std::shared_ptr<Allocator>& allocator)
		: mAllocator(allocator) {}

		template <typename T>
		AllocationType allocate(T&& request) {
		return mAllocator->allocate(std::forward<T>(request));
		}

		void deallocate(const AllocationType& allocation) {
		if (!allocation) return;
		mAllocator->deallocate(allocation);
		}

		// We can't implement deallocate_all/dump/owns, since we may not be the only allocator with
		// access to the underlying allocator (making it not well-defined). If these
		// methods are necesesary, we need to wrap with a snooping allocator.
		private:
		const std::shared_ptr<Allocator> mAllocator;
		};

		// Stateless. This allocator allocates full page-aligned MemoryHeapBases (backed by
		// a shared memory mapped anonymous file) as allocations.
		class MemoryHeapBaseAllocator {
		public:
		static constexpr size_t alignment() { return 4096; /* PAGE_SIZE */ }
		static constexpr unsigned FLAGS = 0; // default flags

		template <typename T>
		AllocationType allocate(T&& request) {
		static_assert(std::is_base_of_v<BasicAllocRequest, std::decay_t<T>>);
		auto heap =
		sp<MemoryHeapBase>::make(shared_allocator_impl::roundup(request.size, alignment()));
		if (!shared_allocator_impl::isHeapValid(heap)) {
		return {};
		}
		return sp<MemoryBase>::make(heap, 0, heap->getSize());
		}

		// Passing a block not allocated by a HeapAllocator is undefined.
		void deallocate(const AllocationType& allocation) {
		if (!allocation) return;
		const auto heap = allocation->getMemory();
		if (!heap) return;
		// This causes future mapped accesses (even across process boundaries)
		// to receive SIGBUS.
		ftruncate(heap->getHeapID(), 0);
		// This static cast is safe, since as long as the block was originally
		// allocated by us, the underlying IMemoryHeap was a MemoryHeapBase
		static_cast<MemoryHeapBase&>(*heap).dispose();
		}
		};
		} // namespace android::mediautils

media/utils/tests/Android.bp

+9 −0

Original line number	Diff line number	Diff line
		@@ -59,6 +59,7 @@ cc_defaults {
		host_supported: true,

		shared_libs: [
		"libbinder",
		"liblog",
		"libmediautils",
		"libutils",
		@@ -224,3 +225,11 @@ cc_test {
		"inplace_function_tests.cpp",
		],
		}

		cc_test {
		name: "shared_memory_allocator_tests",
		defaults: ["libmediautils_tests_defaults"],
		srcs: [
		"shared_memory_allocator_tests.cpp",
		],
		}

media/utils/tests/shared_memory_allocator_tests.cpp

0 → 100644

+350 −0

File added.

Preview size limit exceeded, changes collapsed.

services/audioflinger/AllocatorFactory.h

0 → 100644

+95 −0

Original line number	Diff line number	Diff line
		/*
		**
		** Copyright 2022, 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 <mediautils/SharedMemoryAllocator.h>

		#pragma once

		// TODO how do we appropriately restrict visibility of this header?
		// It should only be included in AudioFlinger.h
		// We will make everything internal linkage for now.
		namespace android {
		namespace AllocatorFactory {
		namespace {
		// TODO make sure these are appropriate
		constexpr inline size_t MAX_MEMORY_SIZE = 1024 * 1024 * 100; // 100 MiB
		constexpr inline size_t DED_SIZE = (MAX_MEMORY_SIZE * 4) / 10; // 40 MiB
		constexpr inline size_t SHARED_SIZE = MAX_MEMORY_SIZE - DED_SIZE; // 60 MiB
		constexpr inline size_t SHARED_SIZE_LARGE = (SHARED_SIZE * 4) / 6; // 40 MiB
		constexpr inline size_t SHARED_SIZE_SMALL = SHARED_SIZE - SHARED_SIZE_LARGE; // 20 MiB
		constexpr inline size_t SMALL_THRESHOLD = 1024 * 40; // 40 KiB

		inline auto getDedicated() {
		using namespace mediautils;
		static const auto allocator =
		std::make_shared<PolicyAllocator<MemoryHeapBaseAllocator, SizePolicy<DED_SIZE>>>();
		return allocator;
		}

		inline auto getSharedLarge() {
		using namespace mediautils;
		static const auto allocator = std::make_shared<
		PolicyAllocator<MemoryHeapBaseAllocator, SizePolicy<SHARED_SIZE_LARGE>>>();
		return allocator;
		}

		inline auto getSharedSmall() {
		using namespace mediautils;
		static const auto allocator =
		std::make_shared<PolicyAllocator<MemoryHeapBaseAllocator,
		SizePolicy<SHARED_SIZE_SMALL, 0, SMALL_THRESHOLD>>>();
		return allocator;
		}

		template <typename Policy, typename Allocator>
		inline auto wrapWithPolicySnooping(Allocator allocator, std::string_view name) {
		using namespace mediautils;
		return SnoopingAllocator{PolicyAllocator{IndirectAllocator{allocator}, Policy{}}, name};
		}

		// A reasonable upper bound on how many clients we expect, and how many pieces to slice
		// the dedicate pool.
		constexpr inline size_t CLIENT_BOUND = 32;
		// Maximum amount of shared pools a single client can take (50%).
		constexpr inline size_t ADV_THRESHOLD_INV = 2;

		inline auto getClientAllocator() {
		using namespace mediautils;
		const auto makeDedPool = []() {
		return wrapWithPolicySnooping<SizePolicy<DED_SIZE / CLIENT_BOUND>>(getDedicated(),
		"Dedicated Pool");
		};
		const auto makeLargeShared = []() {
		return wrapWithPolicySnooping<SizePolicy<SHARED_SIZE_LARGE / ADV_THRESHOLD_INV>>(
		getSharedLarge(), "Large Shared");
		};
		const auto makeSmallShared = []() {
		return wrapWithPolicySnooping<
		SizePolicy<SHARED_SIZE_SMALL / ADV_THRESHOLD_INV>>(
		getSharedSmall(), "Small Shared");
		};

		return ScopedAllocator{std::make_shared<
		FallbackAllocator<decltype(makeDedPool()),
		decltype(FallbackAllocator(makeLargeShared(), makeSmallShared()))>>(
		makeDedPool(), FallbackAllocator{makeLargeShared(), makeSmallShared()})};
		}

		using ClientAllocator = decltype(getClientAllocator());
		} // namespace
		} // namespace AllocatorFactory
		} // namespace android

services/audioflinger/AudioFlinger.cpp

+7 −11

Original line number	Diff line number	Diff line
		@@ -736,8 +736,8 @@ void AudioFlinger::dumpClients(int fd, const Vector<String16>& args __unused)
		for (size_t i = 0; i < mClients.size(); ++i) {
		sp<Client> client = mClients.valueAt(i).promote();
		if (client != 0) {
		result.appendFormat("%6d %12zu\n", client->pid(),
		client->heap()->getMemoryHeap()->getSize());
		result.append("Client: %d\n", client->pid());
		result.append(client->allocator().dump().c_str());
		}
		}

		@@ -2186,12 +2186,8 @@ sp<AudioFlinger::ThreadBase> AudioFlinger::getEffectThread_l(audio_session_t ses
		AudioFlinger::Client::Client(const sp<AudioFlinger>& audioFlinger, pid_t pid)
		: RefBase(),
		mAudioFlinger(audioFlinger),
		mPid(pid)
		{
		mMemoryDealer = new MemoryDealer(
		audioFlinger->getClientSharedHeapSize(),
		(std::string("AudioFlinger::Client(") + std::to_string(pid) + ")").c_str());
		}
		mPid(pid),
		mClientAllocator(AllocatorFactory::getClientAllocator()) {}

		// Client destructor must be called with AudioFlinger::mClientLock held
		AudioFlinger::Client::~Client()
		@@ -2199,9 +2195,9 @@ AudioFlinger::Client::~Client()
		mAudioFlinger->removeClient_l(mPid);
		}

		sp<MemoryDealer> AudioFlinger::Client::heap() const
		AllocatorFactory::ClientAllocator& AudioFlinger::Client::allocator()
		{
		return mMemoryDealer;
		return mClientAllocator;
		}

		// ----------------------------------------------------------------------------