Mordor is a high performance I/O library based on fibers. the forked version even more high performance by changing the core model and include some optimizations.
C++ Other C Objective-C Shell
Clone or download
Pull request Compare This branch is 28 commits ahead, 227 commits behind mozy:next.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.


What is it?

Mordor is a high performance I/O library. It is cross-platform, compiling on Windows, Linux, and Mac (32-bit and 64-bit on all platforms). It includes several main areas:

  • Cooperatively scheduled fiber engine, including synchronization primitives
  • Streams library, for dealing with streams of data and manipulating them.
  • HTTP library, building on top of Fibers and Streams, to provide a simple to use, yet extremely powerful HTTP client and server API including SSL/TLS.
  • Supporting infrastructure, including logging, configuration, statistics gathering, and exceptions.
  • A unit test framework that is lightweight, easy to use, but has several useful features.

One of the main goals of Mordor is to provide very easy to use abstractions and encapsulation of difficult and complex concepts, yet still provide near absolute power in weilding them if necessary.

Where should it be used?

Any software (server-side or client-side) that need to process a lot of data. It is C++, so is probably overkill for something that could be easily handled with a Python or Ruby script, but can be used for simpler tasks because it does provide some nice abstractions that you won't see elsewhere. Server applications handling lots of connections will benefit most from the Fiber engine, by transforming an event-based paradigm into a familiar thread-based paradigm, while keeping (and in some cases improving) the performance of an event-based paradigm.

How does it change the game?

Mordor allows you to focus on performing a logical task, instead of deciding how to make that task conform to a specific threading/event model. Just because local disk I/O will block, and should be performed in a thread pool, and network I/O should be performed using an event based callback design, doesn't mean you can't do them both in the same function. Mordor allows you to do just that. For example, here's a complete program for simple http file server (mordor/examples/simplehttpfileserver.cpp):

#include "mordor/predef.h"

#include <iostream>

#include <boost/thread.hpp>

#include "mordor/config.h"
#include "mordor/http/server.h"
#include "mordor/iomanager.h"
#include "mordor/main.h"
#include "mordor/socket.h"
#include "mordor/streams/file.h"
#include "mordor/streams/socket.h"
#include "mordor/streams/transfer.h"
#include "mordor/streams/ssl.h"

using namespace Mordor;

static void httpRequest(HTTP::ServerRequest::ptr request)
	const std::string &method = request->request().requestLine.method;
	const URI &uri = request->request().requestLine.uri;

    if (method == HTTP::GET) {
		FileStream::ptr stream(new FileStream(uri.path.toString(), FileStream::READ, FileStream::OPEN, static_cast<IOManager*>(Scheduler::getThis()), Scheduler::getThis()));
		HTTP::respondStream(request, stream);
	} else {
	    HTTP::respondError(request, HTTP::METHOD_NOT_ALLOWED);

void serve(Socket::ptr listen, bool ssl)
	IOManager ioManager;
	SSL_CTX* ssl_ctx = NULL;

	if (ssl)
	    ssl_ctx = SSLStream::createSSLCTX();

    while (true)
		Socket::ptr socket = listen->accept(&ioManager);
		SocketStream::ptr socketStream(new SocketStream(socket));

		Stream::ptr stream;

		if (ssl)
			SSLStream::ptr sslStream(new SSLStream(socketStream, false, true, ssl_ctx));
		    stream = sslStream;
			stream = socketStream;

		HTTP::ServerConnection::ptr conn(new HTTP::ServerConnection(stream, &httpRequest));
		Scheduler::getThis()->schedule(boost::bind(&HTTP::ServerConnection::processRequests, conn));

MORDOR_MAIN(int argc, char *argv[])
    try {
        IOManager ioManager;

        Socket::ptr httpSocket = Socket::ptr(new Socket(ioManager, AF_INET, SOCK_STREAM));
        IPv4Address httpAddress(INADDR_ANY, 8080);

        Socket::ptr httpsSocket = Socket::ptr(new Socket(ioManager, AF_INET, SOCK_STREAM));
        IPv4Address httpsAddress(INADDR_ANY, 8443);

        boost::thread serveThread1(serve, httpSocket, false);
		boost::thread serveThread2(serve, httpSocket, false);
		boost::thread serveThread3(serve, httpsSocket, true);
		boost::thread serveThread4(serve, httpsSocket, true);

    } catch (...) {
        std::cerr << boost::current_exception_diagnostic_information() << std::endl;
    return 0;

The IOManager is the object used for non-blocking network I/O, and so is passed to the Socket when it is created. The FileStream need a scheduler object to schedule the non-blocking file I/O, so in that case it use the scheduler of network I/O, so the scheduling of incoming connections/processing and read from file system play in the same scheduler without any callbacks! Something to point out here is that when the work is scheduled on the IOManager, each bit of work implicitly creates a Fiber - a lightweight, cooperatively scheduled, user-mode thread. In that example we have 2 native threads handlers for each HTTP/HTTPS.


  • boost 1.49
  • OpenSSL
  • Zlib
  • Ragel (compile-time only)
  • tcmalloc (optional)



for debug:

~/mordor/buildtools/ debug


So I follow the benchmark from Monkey website (Benchmark: Monkey v/s GWan in a Linux 64 bit platform)

and perform the benchmark myself on file with sizeof 1312 bytes.

I run the test 3 times for each server and choose the best one.

Monkey vs GWan vs original Mordor vs cmpxchg16/Mordor


Intel board, some details:

  • Kernel : 3.5.0 - x86_64 (Ubuntu 12.10)
  • CPU : Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz (4 cores)
  • RAM : 4 GB
  • Filesystem: ext4 on a SSD


** SIEGE 2.70
** Preparing 500 concurrent users for battle.
The server is now under siege...
Lifting the server siege...      done.
Transactions:		       66914 hits
Availability:		      100.00 %
Elapsed time:		        9.68 secs
Data transferred:	       31.46 MB
Response time:		        0.07 secs
Transaction rate:	     6912.60 trans/sec
Throughput:		        3.25 MB/sec
Concurrency:		      490.04
Successful transactions:       66914
Failed transactions:	           0
Longest transaction:	        1.00
Shortest transaction:	        0.00


** SIEGE 2.70
** Preparing 500 concurrent users for battle.
The server is now under siege...
Lifting the server siege...      done.
Transactions:		       73447 hits
Availability:		      100.00 %
Elapsed time:		        9.46 secs
Data transferred:	       95.54 MB
Response time:		        0.06 secs
Transaction rate:	     7763.95 trans/sec
Throughput:		       10.10 MB/sec
Concurrency:		      490.98
Successful transactions:       73448
Failed transactions:	           0
Longest transaction:	        0.77
Shortest transaction:	        0.00

Original Mordor:

** SIEGE 2.70
** Preparing 500 concurrent users for battle.
The server is now under siege...
Lifting the server siege...      done.
Transactions:		       20882 hits
Availability:		      100.00 %
Elapsed time:		        9.06 secs
Data transferred:	       26.13 MB
Response time:		        0.18 secs
Transaction rate:	     2304.86 trans/sec
Throughput:		        2.88 MB/sec
Concurrency:		      410.50
Successful transactions:       20882
Failed transactions:	           0
Longest transaction:	        7.39
Shortest transaction:	        0.01


** SIEGE 2.70
** Preparing 500 concurrent users for battle.
The server is now under siege...
Lifting the server siege...      done.
Transactions:		       67896 hits
Availability:		      100.00 %
Elapsed time:		        9.62 secs
Data transferred:	       88.32 MB
Response time:		        0.07 secs
Transaction rate:	     7057.80 trans/sec
Throughput:		        9.18 MB/sec
Concurrency:		      488.34
Successful transactions:       67896
Failed transactions:	           0
Longest transaction:	        1.42
Shortest transaction:	        0.00
  • cmpxchg16/Mordor 3x than original Mordor
  • cmpxchg16/Mordor slightly better from GWan
  • Monkey slightly better

But! don't forget that Mordor without the callbacks hell! you write synchronous network/file I/O, and under the hood it's asynchronous.

Important Notes:

  • To gain more performance, the locks in scheduling executions was eliminated, the core was changed so Scheduler can run only on one native thread and doesn't create native threads, yet not all the examples was migrated to that model, so it could be that some examples will not work properly due to assertion that validate the model (migrated examples::simplefileserver, simpleappserver, echoserver)
  • The core include stacks pool, so we reuse stacks and eliminate system calls for new/delete stack, the size of the pool can be configured and it's should be fine tune because its affect on performance


Mordor is licensed under the New BSD License See LICENSE for details.


Uri Shamay (