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rippled/Subtrees/websocket/examples/concurrent_server/concurrent_server.cpp

223 lines
8.1 KiB
C++

/*
* Copyright (c) 2011, Peter Thorson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the WebSocket++ Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "../../src/websocketpp.hpp"
#include <boost/thread/thread.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/thread/condition_variable.hpp>
#include <cstring>
#include <sstream>
using websocketpp::server;
// A request encapsulates all of the information necesssary to perform a request
// the coordinator will fill in this information from the websocket connection
// and add it to the processing queue. Sleeping in this example is a placeholder
// for any long serial task.
struct request {
server::handler::connection_ptr con;
int value;
void process() {
std::stringstream response;
response << "Sleeping for " << value << " milliseconds!";
con->send(response.str());
boost::this_thread::sleep(boost::posix_time::milliseconds(value));
response.str("");
response << "Done sleeping for " << value << " milliseconds!";
con->send(response.str());
}
};
// The coordinator is a simple wrapper around an STL queue. add_request inserts
// a new request. get_request returns the next available request and blocks
// (using condition variables) in the case that the queue is empty.
class request_coordinator {
public:
void add_request(const request& r) {
boost::unique_lock<boost::mutex> lock(m_lock);
m_requests.push(r);
lock.unlock();
m_cond.notify_one();
}
void get_request(request& value) {
boost::unique_lock<boost::mutex> lock(m_lock);
while (m_requests.empty()) {
m_cond.wait(lock);
}
value = m_requests.front();
m_requests.pop();
}
private:
std::queue<request> m_requests;
boost::mutex m_lock;
boost::condition_variable m_cond;
};
// The WebSocket++ handler in this case reads numbers from connections and packs
// connection pointer + number into a request struct and passes it off to the
// coordinator.
class concurrent_server_handler : public server::handler {
public:
concurrent_server_handler(request_coordinator& c) : m_coordinator(c) {}
void on_message(connection_ptr con,message_ptr msg) {
int value = atoi(msg->get_payload().c_str());
if (value == 0) {
con->send("Invalid sleep value.");
} else {
request r;
r.con = con;
r.value = value;
m_coordinator.add_request(r);
}
}
private:
request_coordinator& m_coordinator;
};
class server_handler : public server::handler {
public:
void on_message(connection_ptr con,message_ptr msg) {
int value = atoi(msg->get_payload().c_str());
if (value == 0) {
con->send("Invalid sleep value.");
} else {
request r;
r.con = con;
r.value = value;
r.process();
}
}
};
// process_requests is the body function for a processing thread. It loops
// forever reading requests, processing them serially, then reading another
// request.
void process_requests(request_coordinator* coordinator);
void process_requests(request_coordinator* coordinator) {
request r;
while (1) {
coordinator->get_request(r);
r.process();
}
}
// usage: <port> <thread_pool_threads> <worker_threads>
//
// port = port to listen on
// thread_pool_threads = number of threads in the pool running io_service.run()
// worker_threads = number of threads in the sleep work pool.
//
// thread_pool_threads determines the number of threads that process i/o handlers. This
// must be at least one. Handlers and callbacks for individual connections are always
// serially executed within that connection. An i/o thread pool will not improve
// performance in cases where number of connections < number of threads in pool.
//
// worker_threads=0 Standard non-threaded WebSocket++ mode. Handlers will block
// i/o operations within their own connection.
// worker_threads=1 A single work thread processes requests serially separate from the i/o
// thread(s). This allows new connections and requests to be made while the
// processing thread is busy, but does allow long jobs to
// monopolize the processor increasing request latency.
// worker_threads>1 Multiple work threads will work on the single queue of
// requests provided by the i/o thread(s). This enables out of order
// completion of requests. The number of threads can be tuned
// based on hardware concurrency available and expected load and
// job length.
int main(int argc, char* argv[]) {
unsigned short port = 9002;
size_t worker_threads = 2;
size_t pool_threads = 2;
try {
if (argc >= 2) {
std::stringstream buffer(argv[1]);
buffer >> port;
}
if (argc >= 3) {
std::stringstream buffer(argv[2]);
buffer >> pool_threads;
}
if (argc >= 4) {
std::stringstream buffer(argv[3]);
buffer >> worker_threads;
}
request_coordinator rc;
server::handler::ptr h;
if (worker_threads == 0) {
h = server::handler::ptr(new server_handler());
} else {
h = server::handler::ptr(new concurrent_server_handler(rc));
}
server echo_endpoint(h);
echo_endpoint.alog().unset_level(websocketpp::log::alevel::ALL);
echo_endpoint.elog().unset_level(websocketpp::log::elevel::ALL);
echo_endpoint.elog().set_level(websocketpp::log::elevel::RERROR);
echo_endpoint.elog().set_level(websocketpp::log::elevel::FATAL);
std::list<boost::shared_ptr<boost::thread> > threads;
if (worker_threads > 0) {
for (size_t i = 0; i < worker_threads; i++) {
threads.push_back(
boost::shared_ptr<boost::thread>(
new boost::thread(boost::bind(&process_requests, &rc))
)
);
}
}
std::cout << "Starting WebSocket sleep server on port " << port
<< " with thread pool size " << pool_threads << " and "
<< worker_threads << " worker threads." << std::endl;
echo_endpoint.listen(port,pool_threads);
} catch (std::exception& e) {
std::cerr << "Exception: " << e.what() << std::endl;
}
return 0;
}