Thrift now a TLP - INFRA-3116
git-svn-id: https://svn.apache.org/repos/asf/thrift/branches/0.1.x@1028168 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/src/concurrency/ThreadManager.cpp b/lib/cpp/src/concurrency/ThreadManager.cpp
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+++ b/lib/cpp/src/concurrency/ThreadManager.cpp
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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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 "ThreadManager.h"
+#include "Exception.h"
+#include "Monitor.h"
+
+#include <boost/shared_ptr.hpp>
+
+#include <assert.h>
+#include <queue>
+#include <set>
+
+#if defined(DEBUG)
+#include <iostream>
+#endif //defined(DEBUG)
+
+namespace apache { namespace thrift { namespace concurrency {
+
+using boost::shared_ptr;
+using boost::dynamic_pointer_cast;
+
+/**
+ * ThreadManager class
+ *
+ * This class manages a pool of threads. It uses a ThreadFactory to create
+ * threads. It never actually creates or destroys worker threads, rather
+ * it maintains statistics on number of idle threads, number of active threads,
+ * task backlog, and average wait and service times.
+ *
+ * @version $Id:$
+ */
+class ThreadManager::Impl : public ThreadManager {
+
+ public:
+ Impl() :
+ workerCount_(0),
+ workerMaxCount_(0),
+ idleCount_(0),
+ pendingTaskCountMax_(0),
+ state_(ThreadManager::UNINITIALIZED) {}
+
+ ~Impl() { stop(); }
+
+ void start();
+
+ void stop() { stopImpl(false); }
+
+ void join() { stopImpl(true); }
+
+ const ThreadManager::STATE state() const {
+ return state_;
+ }
+
+ shared_ptr<ThreadFactory> threadFactory() const {
+ Synchronized s(monitor_);
+ return threadFactory_;
+ }
+
+ void threadFactory(shared_ptr<ThreadFactory> value) {
+ Synchronized s(monitor_);
+ threadFactory_ = value;
+ }
+
+ void addWorker(size_t value);
+
+ void removeWorker(size_t value);
+
+ size_t idleWorkerCount() const {
+ return idleCount_;
+ }
+
+ size_t workerCount() const {
+ Synchronized s(monitor_);
+ return workerCount_;
+ }
+
+ size_t pendingTaskCount() const {
+ Synchronized s(monitor_);
+ return tasks_.size();
+ }
+
+ size_t totalTaskCount() const {
+ Synchronized s(monitor_);
+ return tasks_.size() + workerCount_ - idleCount_;
+ }
+
+ size_t pendingTaskCountMax() const {
+ Synchronized s(monitor_);
+ return pendingTaskCountMax_;
+ }
+
+ void pendingTaskCountMax(const size_t value) {
+ Synchronized s(monitor_);
+ pendingTaskCountMax_ = value;
+ }
+
+ bool canSleep();
+
+ void add(shared_ptr<Runnable> value, int64_t timeout);
+
+ void remove(shared_ptr<Runnable> task);
+
+private:
+ void stopImpl(bool join);
+
+ size_t workerCount_;
+ size_t workerMaxCount_;
+ size_t idleCount_;
+ size_t pendingTaskCountMax_;
+
+ ThreadManager::STATE state_;
+ shared_ptr<ThreadFactory> threadFactory_;
+
+
+ friend class ThreadManager::Task;
+ std::queue<shared_ptr<Task> > tasks_;
+ Monitor monitor_;
+ Monitor workerMonitor_;
+
+ friend class ThreadManager::Worker;
+ std::set<shared_ptr<Thread> > workers_;
+ std::set<shared_ptr<Thread> > deadWorkers_;
+ std::map<const Thread::id_t, shared_ptr<Thread> > idMap_;
+};
+
+class ThreadManager::Task : public Runnable {
+
+ public:
+ enum STATE {
+ WAITING,
+ EXECUTING,
+ CANCELLED,
+ COMPLETE
+ };
+
+ Task(shared_ptr<Runnable> runnable) :
+ runnable_(runnable),
+ state_(WAITING) {}
+
+ ~Task() {}
+
+ void run() {
+ if (state_ == EXECUTING) {
+ runnable_->run();
+ state_ = COMPLETE;
+ }
+ }
+
+ private:
+ shared_ptr<Runnable> runnable_;
+ friend class ThreadManager::Worker;
+ STATE state_;
+};
+
+class ThreadManager::Worker: public Runnable {
+ enum STATE {
+ UNINITIALIZED,
+ STARTING,
+ STARTED,
+ STOPPING,
+ STOPPED
+ };
+
+ public:
+ Worker(ThreadManager::Impl* manager) :
+ manager_(manager),
+ state_(UNINITIALIZED),
+ idle_(false) {}
+
+ ~Worker() {}
+
+ private:
+ bool isActive() const {
+ return
+ (manager_->workerCount_ <= manager_->workerMaxCount_) ||
+ (manager_->state_ == JOINING && !manager_->tasks_.empty());
+ }
+
+ public:
+ /**
+ * Worker entry point
+ *
+ * As long as worker thread is running, pull tasks off the task queue and
+ * execute.
+ */
+ void run() {
+ bool active = false;
+ bool notifyManager = false;
+
+ /**
+ * Increment worker semaphore and notify manager if worker count reached
+ * desired max
+ *
+ * Note: We have to release the monitor and acquire the workerMonitor
+ * since that is what the manager blocks on for worker add/remove
+ */
+ {
+ Synchronized s(manager_->monitor_);
+ active = manager_->workerCount_ < manager_->workerMaxCount_;
+ if (active) {
+ manager_->workerCount_++;
+ notifyManager = manager_->workerCount_ == manager_->workerMaxCount_;
+ }
+ }
+
+ if (notifyManager) {
+ Synchronized s(manager_->workerMonitor_);
+ manager_->workerMonitor_.notify();
+ notifyManager = false;
+ }
+
+ while (active) {
+ shared_ptr<ThreadManager::Task> task;
+
+ /**
+ * While holding manager monitor block for non-empty task queue (Also
+ * check that the thread hasn't been requested to stop). Once the queue
+ * is non-empty, dequeue a task, release monitor, and execute. If the
+ * worker max count has been decremented such that we exceed it, mark
+ * ourself inactive, decrement the worker count and notify the manager
+ * (technically we're notifying the next blocked thread but eventually
+ * the manager will see it.
+ */
+ {
+ Synchronized s(manager_->monitor_);
+ active = isActive();
+
+ while (active && manager_->tasks_.empty()) {
+ manager_->idleCount_++;
+ idle_ = true;
+ manager_->monitor_.wait();
+ active = isActive();
+ idle_ = false;
+ manager_->idleCount_--;
+ }
+
+ if (active) {
+ if (!manager_->tasks_.empty()) {
+ task = manager_->tasks_.front();
+ manager_->tasks_.pop();
+ if (task->state_ == ThreadManager::Task::WAITING) {
+ task->state_ = ThreadManager::Task::EXECUTING;
+ }
+
+ /* If we have a pending task max and we just dropped below it, wakeup any
+ thread that might be blocked on add. */
+ if (manager_->pendingTaskCountMax_ != 0 &&
+ manager_->tasks_.size() == manager_->pendingTaskCountMax_ - 1) {
+ manager_->monitor_.notify();
+ }
+ }
+ } else {
+ idle_ = true;
+ manager_->workerCount_--;
+ notifyManager = (manager_->workerCount_ == manager_->workerMaxCount_);
+ }
+ }
+
+ if (task != NULL) {
+ if (task->state_ == ThreadManager::Task::EXECUTING) {
+ try {
+ task->run();
+ } catch(...) {
+ // XXX need to log this
+ }
+ }
+ }
+ }
+
+ {
+ Synchronized s(manager_->workerMonitor_);
+ manager_->deadWorkers_.insert(this->thread());
+ if (notifyManager) {
+ manager_->workerMonitor_.notify();
+ }
+ }
+
+ return;
+ }
+
+ private:
+ ThreadManager::Impl* manager_;
+ friend class ThreadManager::Impl;
+ STATE state_;
+ bool idle_;
+};
+
+
+ void ThreadManager::Impl::addWorker(size_t value) {
+ std::set<shared_ptr<Thread> > newThreads;
+ for (size_t ix = 0; ix < value; ix++) {
+ class ThreadManager::Worker;
+ shared_ptr<ThreadManager::Worker> worker = shared_ptr<ThreadManager::Worker>(new ThreadManager::Worker(this));
+ newThreads.insert(threadFactory_->newThread(worker));
+ }
+
+ {
+ Synchronized s(monitor_);
+ workerMaxCount_ += value;
+ workers_.insert(newThreads.begin(), newThreads.end());
+ }
+
+ for (std::set<shared_ptr<Thread> >::iterator ix = newThreads.begin(); ix != newThreads.end(); ix++) {
+ shared_ptr<ThreadManager::Worker> worker = dynamic_pointer_cast<ThreadManager::Worker, Runnable>((*ix)->runnable());
+ worker->state_ = ThreadManager::Worker::STARTING;
+ (*ix)->start();
+ idMap_.insert(std::pair<const Thread::id_t, shared_ptr<Thread> >((*ix)->getId(), *ix));
+ }
+
+ {
+ Synchronized s(workerMonitor_);
+ while (workerCount_ != workerMaxCount_) {
+ workerMonitor_.wait();
+ }
+ }
+}
+
+void ThreadManager::Impl::start() {
+
+ if (state_ == ThreadManager::STOPPED) {
+ return;
+ }
+
+ {
+ Synchronized s(monitor_);
+ if (state_ == ThreadManager::UNINITIALIZED) {
+ if (threadFactory_ == NULL) {
+ throw InvalidArgumentException();
+ }
+ state_ = ThreadManager::STARTED;
+ monitor_.notifyAll();
+ }
+
+ while (state_ == STARTING) {
+ monitor_.wait();
+ }
+ }
+}
+
+void ThreadManager::Impl::stopImpl(bool join) {
+ bool doStop = false;
+ if (state_ == ThreadManager::STOPPED) {
+ return;
+ }
+
+ {
+ Synchronized s(monitor_);
+ if (state_ != ThreadManager::STOPPING &&
+ state_ != ThreadManager::JOINING &&
+ state_ != ThreadManager::STOPPED) {
+ doStop = true;
+ state_ = join ? ThreadManager::JOINING : ThreadManager::STOPPING;
+ }
+ }
+
+ if (doStop) {
+ removeWorker(workerCount_);
+ }
+
+ // XXX
+ // should be able to block here for transition to STOPPED since we're no
+ // using shared_ptrs
+
+ {
+ Synchronized s(monitor_);
+ state_ = ThreadManager::STOPPED;
+ }
+
+}
+
+void ThreadManager::Impl::removeWorker(size_t value) {
+ std::set<shared_ptr<Thread> > removedThreads;
+ {
+ Synchronized s(monitor_);
+ if (value > workerMaxCount_) {
+ throw InvalidArgumentException();
+ }
+
+ workerMaxCount_ -= value;
+
+ if (idleCount_ < value) {
+ for (size_t ix = 0; ix < idleCount_; ix++) {
+ monitor_.notify();
+ }
+ } else {
+ monitor_.notifyAll();
+ }
+ }
+
+ {
+ Synchronized s(workerMonitor_);
+
+ while (workerCount_ != workerMaxCount_) {
+ workerMonitor_.wait();
+ }
+
+ for (std::set<shared_ptr<Thread> >::iterator ix = deadWorkers_.begin(); ix != deadWorkers_.end(); ix++) {
+ workers_.erase(*ix);
+ idMap_.erase((*ix)->getId());
+ }
+
+ deadWorkers_.clear();
+ }
+}
+
+ bool ThreadManager::Impl::canSleep() {
+ const Thread::id_t id = threadFactory_->getCurrentThreadId();
+ return idMap_.find(id) == idMap_.end();
+ }
+
+ void ThreadManager::Impl::add(shared_ptr<Runnable> value, int64_t timeout) {
+ Synchronized s(monitor_);
+
+ if (state_ != ThreadManager::STARTED) {
+ throw IllegalStateException();
+ }
+
+ if (pendingTaskCountMax_ > 0 && (tasks_.size() >= pendingTaskCountMax_)) {
+ if (canSleep() && timeout >= 0) {
+ while (pendingTaskCountMax_ > 0 && tasks_.size() >= pendingTaskCountMax_) {
+ monitor_.wait(timeout);
+ }
+ } else {
+ throw TooManyPendingTasksException();
+ }
+ }
+
+ tasks_.push(shared_ptr<ThreadManager::Task>(new ThreadManager::Task(value)));
+
+ // If idle thread is available notify it, otherwise all worker threads are
+ // running and will get around to this task in time.
+ if (idleCount_ > 0) {
+ monitor_.notify();
+ }
+ }
+
+void ThreadManager::Impl::remove(shared_ptr<Runnable> task) {
+ Synchronized s(monitor_);
+ if (state_ != ThreadManager::STARTED) {
+ throw IllegalStateException();
+ }
+}
+
+class SimpleThreadManager : public ThreadManager::Impl {
+
+ public:
+ SimpleThreadManager(size_t workerCount=4, size_t pendingTaskCountMax=0) :
+ workerCount_(workerCount),
+ pendingTaskCountMax_(pendingTaskCountMax),
+ firstTime_(true) {
+ }
+
+ void start() {
+ ThreadManager::Impl::pendingTaskCountMax(pendingTaskCountMax_);
+ ThreadManager::Impl::start();
+ addWorker(workerCount_);
+ }
+
+ private:
+ const size_t workerCount_;
+ const size_t pendingTaskCountMax_;
+ bool firstTime_;
+ Monitor monitor_;
+};
+
+
+shared_ptr<ThreadManager> ThreadManager::newThreadManager() {
+ return shared_ptr<ThreadManager>(new ThreadManager::Impl());
+}
+
+shared_ptr<ThreadManager> ThreadManager::newSimpleThreadManager(size_t count, size_t pendingTaskCountMax) {
+ return shared_ptr<ThreadManager>(new SimpleThreadManager(count, pendingTaskCountMax));
+}
+
+}}} // apache::thrift::concurrency
+