upload android base code part3

android/art/runtime/thread_pool.h

@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2012 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 ART_RUNTIME_THREAD_POOL_H_
+#define ART_RUNTIME_THREAD_POOL_H_
+
+#include <deque>
+#include <vector>
+
+#include "barrier.h"
+#include "base/mutex.h"
+#include "mem_map.h"
+
+namespace art {
+
+class ThreadPool;
+
+class Closure {
+ public:
+  virtual ~Closure() { }
+  virtual void Run(Thread* self) = 0;
+};
+
+class Task : public Closure {
+ public:
+  // Called after Closure::Run has been called.
+  virtual void Finalize() { }
+};
+
+class SelfDeletingTask : public Task {
+ public:
+  virtual ~SelfDeletingTask() { }
+  virtual void Finalize() {
+    delete this;
+  }
+};
+
+class ThreadPoolWorker {
+ public:
+  static const size_t kDefaultStackSize = 1 * MB;
+
+  size_t GetStackSize() const {
+    DCHECK(stack_.get() != nullptr);
+    return stack_->Size();
+  }
+
+  virtual ~ThreadPoolWorker();
+
+  // Set the "nice" priorty for this worker.
+  void SetPthreadPriority(int priority);
+
+  Thread* GetThread() const { return thread_; }
+
+ protected:
+  ThreadPoolWorker(ThreadPool* thread_pool, const std::string& name, size_t stack_size);
+  static void* Callback(void* arg) REQUIRES(!Locks::mutator_lock_);
+  virtual void Run();
+
+  ThreadPool* const thread_pool_;
+  const std::string name_;
+  std::unique_ptr<MemMap> stack_;
+  pthread_t pthread_;
+  Thread* thread_;
+
+ private:
+  friend class ThreadPool;
+  DISALLOW_COPY_AND_ASSIGN(ThreadPoolWorker);
+};
+
+// Note that thread pool workers will set Thread#setCanCallIntoJava to false.
+class ThreadPool {
+ public:
+  // Returns the number of threads in the thread pool.
+  size_t GetThreadCount() const {
+    return threads_.size();
+  }
+
+  const std::vector<ThreadPoolWorker*>& GetWorkers() const {
+    return threads_;
+  }
+
+  // Broadcast to the workers and tell them to empty out the work queue.
+  void StartWorkers(Thread* self) REQUIRES(!task_queue_lock_);
+
+  // Do not allow workers to grab any new tasks.
+  void StopWorkers(Thread* self) REQUIRES(!task_queue_lock_);
+
+  // Add a new task, the first available started worker will process it. Does not delete the task
+  // after running it, it is the caller's responsibility.
+  void AddTask(Thread* self, Task* task) REQUIRES(!task_queue_lock_);
+
+  // Remove all tasks in the queue.
+  void RemoveAllTasks(Thread* self) REQUIRES(!task_queue_lock_);
+
+  // Create a named thread pool with the given number of threads.
+  //
+  // If create_peers is true, all worker threads will have a Java peer object. Note that if the
+  // pool is asked to do work on the current thread (see Wait), a peer may not be available. Wait
+  // will conservatively abort if create_peers and do_work are true.
+  ThreadPool(const char* name, size_t num_threads, bool create_peers = false);
+  virtual ~ThreadPool();
+
+  // Wait for all tasks currently on queue to get completed. If the pool has been stopped, only
+  // wait till all already running tasks are done.
+  // When the pool was created with peers for workers, do_work must not be true (see ThreadPool()).
+  void Wait(Thread* self, bool do_work, bool may_hold_locks) REQUIRES(!task_queue_lock_);
+
+  size_t GetTaskCount(Thread* self) REQUIRES(!task_queue_lock_);
+
+  // Returns the total amount of workers waited for tasks.
+  uint64_t GetWaitTime() const {
+    return total_wait_time_;
+  }
+
+  // Provides a way to bound the maximum number of worker threads, threads must be less the the
+  // thread count of the thread pool.
+  void SetMaxActiveWorkers(size_t threads) REQUIRES(!task_queue_lock_);
+
+  // Set the "nice" priorty for threads in the pool.
+  void SetPthreadPriority(int priority);
+
+ protected:
+  // get a task to run, blocks if there are no tasks left
+  virtual Task* GetTask(Thread* self) REQUIRES(!task_queue_lock_);
+
+  // Try to get a task, returning null if there is none available.
+  Task* TryGetTask(Thread* self) REQUIRES(!task_queue_lock_);
+  Task* TryGetTaskLocked() REQUIRES(task_queue_lock_);
+
+  // Are we shutting down?
+  bool IsShuttingDown() const REQUIRES(task_queue_lock_) {
+    return shutting_down_;
+  }
+
+  bool HasOutstandingTasks() const REQUIRES(task_queue_lock_) {
+    return started_ && !tasks_.empty();
+  }
+
+  const std::string name_;
+  Mutex task_queue_lock_;
+  ConditionVariable task_queue_condition_ GUARDED_BY(task_queue_lock_);
+  ConditionVariable completion_condition_ GUARDED_BY(task_queue_lock_);
+  volatile bool started_ GUARDED_BY(task_queue_lock_);
+  volatile bool shutting_down_ GUARDED_BY(task_queue_lock_);
+  // How many worker threads are waiting on the condition.
+  volatile size_t waiting_count_ GUARDED_BY(task_queue_lock_);
+  std::deque<Task*> tasks_ GUARDED_BY(task_queue_lock_);
+  // TODO: make this immutable/const?
+  std::vector<ThreadPoolWorker*> threads_;
+  // Work balance detection.
+  uint64_t start_time_ GUARDED_BY(task_queue_lock_);
+  uint64_t total_wait_time_;
+  Barrier creation_barier_;
+  size_t max_active_workers_ GUARDED_BY(task_queue_lock_);
+  const bool create_peers_;
+
+ private:
+  friend class ThreadPoolWorker;
+  friend class WorkStealingWorker;
+  DISALLOW_COPY_AND_ASSIGN(ThreadPool);
+};
+
+}  // namespace art
+
+#endif  // ART_RUNTIME_THREAD_POOL_H_