161 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			161 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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|  * Copyright (C) 2006 The Android Open Source Project
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|  *
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|  * Licensed under the Apache License, Version 2.0 (the "License");
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|  * you may not use this file except in compliance with the License.
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|  * You may obtain a copy of the License at
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|  *
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|  *      http://www.apache.org/licenses/LICENSE-2.0
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|  *
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|  * Unless required by applicable law or agreed to in writing, software
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|  * distributed under the License is distributed on an "AS IS" BASIS,
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|  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|  * See the License for the specific language governing permissions and
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|  * limitations under the License.
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|  */
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| 
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| #ifndef __FDEVENT_H
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| #define __FDEVENT_H
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| 
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| #include <stddef.h>
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| #include <stdint.h>
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| 
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| #include <atomic>
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| #include <chrono>
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| #include <deque>
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| #include <functional>
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| #include <mutex>
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| #include <optional>
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| #include <unordered_map>
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| #include <variant>
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| 
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| #include <android-base/thread_annotations.h>
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| 
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| #include "adb_unique_fd.h"
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| 
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| // Events that may be observed
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| #define FDE_READ 0x0001
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| #define FDE_WRITE 0x0002
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| #define FDE_ERROR 0x0004
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| #define FDE_TIMEOUT 0x0008
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| 
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| struct fdevent;
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| 
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| typedef void (*fd_func)(int fd, unsigned events, void *userdata);
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| typedef void (*fd_func2)(struct fdevent* fde, unsigned events, void* userdata);
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| 
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| void invoke_fde(struct fdevent* fde, unsigned events);
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| std::string dump_fde(const fdevent* fde);
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| 
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| struct fdevent_event {
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|     fdevent* fde;
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|     unsigned events;
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| };
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| 
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| struct fdevent final {
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|     uint64_t id;
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| 
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|     unique_fd fd;
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|     int force_eof = 0;
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| 
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|     uint16_t state = 0;
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|     std::optional<std::chrono::milliseconds> timeout;
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|     std::chrono::steady_clock::time_point last_active;
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| 
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|     std::variant<fd_func, fd_func2> func;
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|     void* arg = nullptr;
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| };
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| 
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| struct fdevent_context {
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|   public:
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|     virtual ~fdevent_context() = default;
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| 
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|     // Allocate and initialize a new fdevent object.
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|     fdevent* Create(unique_fd fd, std::variant<fd_func, fd_func2> func, void* arg);
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| 
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|     // Deallocate an fdevent object, returning the file descriptor that was owned by it.
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|     // Note that this calls Set, which is a virtual method, so destructors that call this must be
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|     // final.
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|     unique_fd Destroy(fdevent* fde);
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| 
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|   protected:
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|     virtual void Register(fdevent*) = 0;
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|     virtual void Unregister(fdevent*) = 0;
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| 
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|   public:
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|     // Change which events should cause notifications.
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|     virtual void Set(fdevent* fde, unsigned events) = 0;
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|     void Add(fdevent* fde, unsigned events);
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|     void Del(fdevent* fde, unsigned events);
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| 
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|     // Set a timeout on an fdevent.
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|     // If no events are triggered by the timeout, an FDE_TIMEOUT will be generated.
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|     // Note timeouts are not defused automatically; if a timeout is set on an fdevent, it will
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|     // trigger repeatedly every |timeout| ms.
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|     void SetTimeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout);
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| 
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|   protected:
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|     std::optional<std::chrono::milliseconds> CalculatePollDuration();
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|     void HandleEvents(const std::vector<fdevent_event>& events);
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| 
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|   private:
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|     // Run all pending functions enqueued via Run().
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|     void FlushRunQueue() EXCLUDES(run_queue_mutex_);
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| 
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|   public:
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|     // Loop until TerminateLoop is called, handling events.
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|     // Implementations should call FlushRunQueue on every iteration, and check the value of
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|     // terminate_loop_ to determine whether to stop.
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|     virtual void Loop() = 0;
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| 
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|     // Assert that the caller is either running on the context's main thread, or that there is no
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|     // active main thread.
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|     void CheckMainThread();
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| 
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|     // Queue an operation to be run on the main thread.
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|     void Run(std::function<void()> fn);
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| 
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|     // Test-only functionality:
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|     void TerminateLoop();
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|     virtual size_t InstalledCount() = 0;
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| 
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|   protected:
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|     // Interrupt the run loop.
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|     virtual void Interrupt() = 0;
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| 
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|     std::optional<uint64_t> main_thread_id_ = std::nullopt;
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|     std::atomic<bool> terminate_loop_ = false;
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| 
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|   protected:
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|     std::unordered_map<int, fdevent> installed_fdevents_;
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| 
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|   private:
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|     uint64_t fdevent_id_ = 0;
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|     std::mutex run_queue_mutex_;
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|     std::deque<std::function<void()>> run_queue_ GUARDED_BY(run_queue_mutex_);
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| };
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| 
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| // Backwards compatibility shims that forward to the global fdevent_context.
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| fdevent* fdevent_create(int fd, fd_func func, void* arg);
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| fdevent* fdevent_create(int fd, fd_func2 func, void* arg);
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| 
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| unique_fd fdevent_release(fdevent* fde);
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| void fdevent_destroy(fdevent* fde);
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| 
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| void fdevent_set(fdevent *fde, unsigned events);
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| void fdevent_add(fdevent *fde, unsigned events);
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| void fdevent_del(fdevent *fde, unsigned events);
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| void fdevent_set_timeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout);
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| void fdevent_loop();
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| void check_main_thread();
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| 
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| // Queue an operation to run on the main thread.
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| void fdevent_run_on_main_thread(std::function<void()> fn);
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| 
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| // The following functions are used only for tests.
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| void fdevent_terminate_loop();
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| size_t fdevent_installed_count();
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| void fdevent_reset();
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| 
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| #endif
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