| // Copyright 2014 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifdef UNSAFE_BUFFERS_BUILD |
| #pragma check_unsafe_buffers |
| #endif |
| |
| #ifndef COMPONENTS_DISCARDABLE_MEMORY_SERVICE_DISCARDABLE_SHARED_MEMORY_MANAGER_H_ |
| #define COMPONENTS_DISCARDABLE_MEMORY_SERVICE_DISCARDABLE_SHARED_MEMORY_MANAGER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <memory> |
| #include <unordered_map> |
| #include <vector> |
| |
| #include "base/format_macros.h" |
| #include "base/functional/callback.h" |
| #include "base/memory/discardable_memory_allocator.h" |
| #include "base/memory/discardable_shared_memory.h" |
| #include "base/memory/memory_pressure_listener.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/unsafe_shared_memory_region.h" |
| #include "base/memory/weak_ptr.h" |
| #include "base/process/process_handle.h" |
| #include "base/synchronization/lock.h" |
| #include "base/task/current_thread.h" |
| #include "base/task/sequenced_task_runner.h" |
| #include "base/task/single_thread_task_runner.h" |
| #include "base/thread_annotations.h" |
| #include "base/trace_event/memory_dump_provider.h" |
| #include "components/discardable_memory/common/discardable_memory_export.h" |
| #include "components/discardable_memory/public/mojom/discardable_shared_memory_manager.mojom.h" |
| #include "mojo/public/cpp/bindings/pending_receiver.h" |
| |
| namespace base { |
| class WaitableEvent; |
| } |
| |
| namespace discardable_memory { |
| |
| namespace { |
| class TestDiscardableSharedMemoryManager; |
| } // namespace |
| |
| // Implementation of DiscardableMemoryAllocator that allocates and manages |
| // discardable memory segments for the process which hosts this class, and |
| // for remote processes which request discardable memory from this class via |
| // IPC. |
| // This class is thread-safe and instances can safely be used on any thread. |
| class DISCARDABLE_MEMORY_EXPORT DiscardableSharedMemoryManager |
| : public base::DiscardableMemoryAllocator, |
| public base::trace_event::MemoryDumpProvider, |
| public base::CurrentThread::DestructionObserver { |
| public: |
| DiscardableSharedMemoryManager(); |
| |
| DiscardableSharedMemoryManager(const DiscardableSharedMemoryManager&) = |
| delete; |
| DiscardableSharedMemoryManager& operator=( |
| const DiscardableSharedMemoryManager&) = delete; |
| |
| ~DiscardableSharedMemoryManager() override; |
| |
| // Returns the global instance of DiscardableSharedMemoryManager, usable from |
| // any thread. May return null if no DiscardableSharedMemoryManager has been |
| // created in the current process. |
| static DiscardableSharedMemoryManager* Get(); |
| |
| // Bind the manager to a mojo interface receiver. |
| void Bind( |
| mojo::PendingReceiver<mojom::DiscardableSharedMemoryManager> receiver); |
| |
| // Overridden from base::DiscardableMemoryAllocator: |
| std::unique_ptr<base::DiscardableMemory> AllocateLockedDiscardableMemory( |
| size_t size) override; |
| |
| // Overridden from base::trace_event::MemoryDumpProvider: |
| bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args, |
| base::trace_event::ProcessMemoryDump* pmd) override; |
| |
| // This allocates a discardable memory segment for |process_handle|. |
| // A valid shared memory region is returned on success. |
| void AllocateLockedDiscardableSharedMemoryForClient( |
| int client_id, |
| size_t size, |
| int32_t id, |
| base::UnsafeSharedMemoryRegion* shared_memory_region); |
| |
| // Call this to notify the manager that client process associated with |
| // |client_id| has deleted discardable memory segment with |id|. |
| void ClientDeletedDiscardableSharedMemory(int32_t id, int client_id); |
| |
| // Call this to notify the manager that client associated with |client_id| |
| // has been removed. The manager will use this to release memory segments |
| // allocated for client to the OS. |
| void ClientRemoved(int client_id); |
| |
| // The maximum number of bytes of memory that may be allocated. This will |
| // cause memory usage to be reduced if currently above |limit|. |
| void SetMemoryLimit(size_t limit); |
| |
| // Reduce memory usage if above current memory limit. |
| void EnforceMemoryPolicy(); |
| |
| // Returns bytes of allocated discardable memory. |
| size_t GetBytesAllocated() const override; |
| |
| void ReleaseFreeMemory() override { |
| // Do nothing since we already subscribe to memory pressure notifications. |
| } |
| |
| private: |
| friend TestDiscardableSharedMemoryManager; |
| |
| class MemorySegment : public base::RefCountedThreadSafe<MemorySegment> { |
| public: |
| MemorySegment(std::unique_ptr<base::DiscardableSharedMemory> memory); |
| |
| MemorySegment(const MemorySegment&) = delete; |
| MemorySegment& operator=(const MemorySegment&) = delete; |
| |
| base::DiscardableSharedMemory* memory() const { return memory_.get(); } |
| |
| private: |
| friend class base::RefCountedThreadSafe<MemorySegment>; |
| |
| ~MemorySegment(); |
| |
| std::unique_ptr<base::DiscardableSharedMemory> memory_; |
| }; |
| |
| static bool CompareMemoryUsageTime(const scoped_refptr<MemorySegment>& a, |
| const scoped_refptr<MemorySegment>& b) { |
| // In this system, LRU memory segment is evicted first. |
| return a->memory()->last_known_usage() > b->memory()->last_known_usage(); |
| } |
| |
| // base::CurrentThread::DestructionObserver implementation: |
| void WillDestroyCurrentMessageLoop() override; |
| |
| void AllocateLockedDiscardableSharedMemory( |
| int client_id, |
| size_t size, |
| int32_t id, |
| base::UnsafeSharedMemoryRegion* shared_memory_region); |
| void DeletedDiscardableSharedMemory(int32_t id, int client_id); |
| // Virtual for tests. |
| virtual void OnMemoryPressure( |
| base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level); |
| void ReduceMemoryUsageUntilWithinMemoryLimit() |
| EXCLUSIVE_LOCKS_REQUIRED(lock_); |
| void ReduceMemoryUsageUntilWithinLimit(size_t limit) |
| EXCLUSIVE_LOCKS_REQUIRED(lock_); |
| void ReleaseMemory(base::DiscardableSharedMemory* memory) |
| EXCLUSIVE_LOCKS_REQUIRED(lock_); |
| void BytesAllocatedChanged(size_t new_bytes_allocated) const; |
| |
| // Virtual for tests. |
| virtual base::Time Now() const; |
| virtual void ScheduleEnforceMemoryPolicy() EXCLUSIVE_LOCKS_REQUIRED(lock_); |
| |
| // Invalidate weak pointers for the mojo thread. |
| void InvalidateMojoThreadWeakPtrs(base::WaitableEvent* event); |
| |
| // Create `memory_pressure_listener_` on a worker thread to receive memory |
| // pressure notifications there. |
| void CreateMemoryPressureListenerOnWorkerThread(); |
| |
| int32_t next_client_id_; |
| |
| mutable base::Lock lock_; |
| using MemorySegmentMap = |
| std::unordered_map<int32_t, scoped_refptr<MemorySegment>>; |
| using ClientMap = std::unordered_map<int, MemorySegmentMap>; |
| ClientMap clients_ GUARDED_BY(lock_); |
| // Note: The elements in |segments_| are arranged in such a way that they form |
| // a heap. The LRU memory segment always first. |
| using MemorySegmentVector = std::vector<scoped_refptr<MemorySegment>>; |
| MemorySegmentVector segments_ GUARDED_BY(lock_); |
| size_t default_memory_limit_ GUARDED_BY(lock_); |
| size_t memory_limit_ GUARDED_BY(lock_); |
| size_t bytes_allocated_ GUARDED_BY(lock_); |
| std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_ |
| GUARDED_BY(lock_); |
| scoped_refptr<base::SingleThreadTaskRunner> enforce_memory_policy_task_runner_ |
| GUARDED_BY(lock_); |
| base::RepeatingClosure enforce_memory_policy_callback_ GUARDED_BY(lock_); |
| bool enforce_memory_policy_pending_ GUARDED_BY(lock_); |
| |
| // The message loop for running mojom::DiscardableSharedMemoryManager |
| // implementations. |
| // TODO(altimin,gab): Allow weak pointers to be deleted on other threads |
| // when the thread is gone and remove this. |
| // A prerequisite for this is allowing objects to be bound to the lifetime |
| // of a sequence directly. |
| base::CurrentThread mojo_thread_message_loop_; |
| scoped_refptr<base::SingleThreadTaskRunner> mojo_thread_task_runner_; |
| |
| // A task runner to create `memory_pressure_listener_` on worker threads so |
| // that `OnMemoryPressure` notification happens on the worker thread too. |
| scoped_refptr<base::SequencedTaskRunner> memory_pressure_task_runner_; |
| |
| base::WeakPtrFactory<DiscardableSharedMemoryManager> weak_ptr_factory_{this}; |
| |
| // WeakPtrFractory for generating weak pointers used in the mojo thread. |
| base::WeakPtrFactory<DiscardableSharedMemoryManager> |
| mojo_thread_weak_ptr_factory_{this}; |
| }; |
| |
| } // namespace discardable_memory |
| |
| #endif // COMPONENTS_DISCARDABLE_MEMORY_SERVICE_DISCARDABLE_SHARED_MEMORY_MANAGER_H_ |