lib/cpp/src/server/TThreadedServer.cpp

// Copyright (c) 2006- Facebook
// Distributed under the Thrift Software License
//
// See accompanying file LICENSE or visit the Thrift site at:
// http://developers.facebook.com/thrift/

#include "server/TThreadedServer.h"
#include "transport/TTransportException.h"
#include "concurrency/PosixThreadFactory.h"

#include <string>
#include <iostream>
#include <pthread.h>
#include <unistd.h>

namespace facebook { namespace thrift { namespace server {

using boost::shared_ptr;
using namespace std;
using namespace facebook::thrift;
using namespace facebook::thrift::protocol;
using namespace facebook::thrift::transport;
using namespace facebook::thrift::concurrency;

class TThreadedServer::Task: public Runnable {

public:

  Task(TThreadedServer& server,
       shared_ptr<TProcessor> processor,
       shared_ptr<TProtocol> input,
       shared_ptr<TProtocol> output) :
    server_(server),
    processor_(processor),
    input_(input),
    output_(output) {
  }

  ~Task() {}

  void run() {
    boost::shared_ptr<TServerEventHandler> eventHandler =
      server_.getEventHandler();
    if (eventHandler != NULL) {
      eventHandler->clientBegin(input_, output_);
    }
    try {
      while (processor_->process(input_, output_)) {
        if (!input_->getTransport()->peek()) {
          break;
        }
      }
    } catch (TTransportException& ttx) {
      string errStr = string("TThreadedServer client died: ") + ttx.what();
      GlobalOutput(errStr.c_str());
    } catch (TException& x) {
      string errStr = string("TThreadedServer exception: ") + x.what();
      GlobalOutput(errStr.c_str());
    } catch (...) {
      GlobalOutput("TThreadedServer uncaught exception.");
    }
    if (eventHandler != NULL) {
      eventHandler->clientEnd(input_, output_);
    }

    try {
      input_->getTransport()->close();
    } catch (TTransportException& ttx) {
      string errStr = string("TThreadedServer input close failed: ") + ttx.what();
      GlobalOutput(errStr.c_str());
    }
    try {
      output_->getTransport()->close();
    } catch (TTransportException& ttx) {
      string errStr = string("TThreadedServer output close failed: ") + ttx.what();
      GlobalOutput(errStr.c_str());
    }

    // Remove this task from parent bookkeeping
    {
      Synchronized s(server_.tasksMonitor_);
      server_.tasks_.erase(this);
      if (server_.tasks_.empty()) {
        server_.tasksMonitor_.notify();
      }
    }

  }

 private:
  TThreadedServer& server_;
  friend class TThreadedServer;

  shared_ptr<TProcessor> processor_;
  shared_ptr<TProtocol> input_;
  shared_ptr<TProtocol> output_;
};


TThreadedServer::TThreadedServer(shared_ptr<TProcessor> processor,
                                 shared_ptr<TServerTransport> serverTransport,
                                 shared_ptr<TTransportFactory> transportFactory,
                                 shared_ptr<TProtocolFactory> protocolFactory):
  TServer(processor, serverTransport, transportFactory, protocolFactory),
  stop_(false) {
  threadFactory_ = shared_ptr<PosixThreadFactory>(new PosixThreadFactory());
}

TThreadedServer::~TThreadedServer() {}

void TThreadedServer::serve() {

  shared_ptr<TTransport> client;
  shared_ptr<TTransport> inputTransport;
  shared_ptr<TTransport> outputTransport;
  shared_ptr<TProtocol> inputProtocol;
  shared_ptr<TProtocol> outputProtocol;

  try {
    // Start the server listening
    serverTransport_->listen();
  } catch (TTransportException& ttx) {
    string errStr = string("TThreadedServer::run() listen(): ") +ttx.what();
    GlobalOutput(errStr.c_str());
    return;
  }

  // Run the preServe event
  if (eventHandler_ != NULL) {
    eventHandler_->preServe();
  }

  while (!stop_) {
    try {
      client.reset();
      inputTransport.reset();
      outputTransport.reset();
      inputProtocol.reset();
      outputProtocol.reset();

      // Fetch client from server
      client = serverTransport_->accept();

      // Make IO transports
      inputTransport = inputTransportFactory_->getTransport(client);
      outputTransport = outputTransportFactory_->getTransport(client);
      inputProtocol = inputProtocolFactory_->getProtocol(inputTransport);
      outputProtocol = outputProtocolFactory_->getProtocol(outputTransport);

      TThreadedServer::Task* task = new TThreadedServer::Task(*this,
                                                              processor_,
                                                              inputProtocol,
                                                              outputProtocol);

      // Create a task
      shared_ptr<Runnable> runnable =
        shared_ptr<Runnable>(task);

      // Create a thread for this task
      shared_ptr<Thread> thread =
        shared_ptr<Thread>(threadFactory_->newThread(runnable));

      // Insert thread into the set of threads
      {
        Synchronized s(tasksMonitor_);
        tasks_.insert(task);
      }

      // Start the thread!
      thread->start();

    } catch (TTransportException& ttx) {
      if (inputTransport != NULL) { inputTransport->close(); }
      if (outputTransport != NULL) { outputTransport->close(); }
      if (client != NULL) { client->close(); }
      if (!stop_ || ttx.getType() != TTransportException::INTERRUPTED) {
        string errStr = string("TThreadedServer: TServerTransport died on accept: ") + ttx.what();
        GlobalOutput(errStr.c_str());
      }
      continue;
    } catch (TException& tx) {
      if (inputTransport != NULL) { inputTransport->close(); }
      if (outputTransport != NULL) { outputTransport->close(); }
      if (client != NULL) { client->close(); }
      string errStr = string("TThreadedServer: Caught TException: ") + tx.what();
      GlobalOutput(errStr.c_str());
      continue;
    } catch (string s) {
      if (inputTransport != NULL) { inputTransport->close(); }
      if (outputTransport != NULL) { outputTransport->close(); }
      if (client != NULL) { client->close(); }
      string errStr = "TThreadedServer: Unknown exception: " + s;
      GlobalOutput(errStr.c_str());
      break;
    }
  }

  // If stopped manually, make sure to close server transport
  if (stop_) {
    try {
      serverTransport_->close();
    } catch (TException &tx) {
      string errStr = string("TThreadedServer: Exception shutting down: ") + tx.what();
      GlobalOutput(errStr.c_str());
    }
    try {
      Synchronized s(tasksMonitor_);
      while (!tasks_.empty()) {
        tasksMonitor_.wait();
      }
    } catch (TException &tx) {
      string errStr = string("TThreadedServer: Exception joining workers: ") + tx.what();
      GlobalOutput(errStr.c_str());
    }
    stop_ = false;
  }

}

}}} // facebook::thrift::server