I really thought this would be easier to find...
I need a portable c++ sockets wrapper. I'm planning to use it for a windows server application and a client that will be running on a embedded device running ulinux (or something similar). I would use Boost but I need it to be lightweight and easy to add to the embedded device project.
Also I would like it to be a "higher level" wrapper... so it starts a background thread to read data and informs be over a callback...
Any ideas?
I'd suggest Boost.Asio. Despite it's name, you are not forced to use asynchronous I/O. You could use synchronous I/O and threads, as your question implies.
Boost.Asio is a cross-platform C++
library for network and low-level I/O
programming that provides developers
with a consistent asynchronous model
using a modern C++ approach.
Just learn to use the socket API directly. You can then easily wrap it yourself. It's not that hard, and you can get started with Beej's excellent guide. As Beej says:
The sockets API, though started by the
Berkeley folk, has been ported to many
many platforms, including Unix, Linux,
and even Windows.
In his guide he details the very small addition you need to do to get the same API in Windows and *nix systems.
Once you've learned, wrap it yourself if you're so inclined. Then you can control exactly how "lightweight" you want it.
If you really don't like Boost asio then you might like the sockets support in dlib. It is simpler in the sense that it uses traditional blocking IO and threads rather than asio's asynchronous proactor pattern. For example, it makes it easy to make a threaded TCP server that reads and writes from the iostreams. See this example for instance. Or you can just make a simple iosockstream if not acting as a server.
I know this is old, but there is a very nice and simple implementation in below location which I'm using for personal use. Had implemented my own wrapper a while back but lost the code and found this one online which is much better than mine:
http://cs.ecs.baylor.edu/~donahoo/practical/CSockets/practical/
Take a look at ENet http://enet.bespin.org/ it is very lightweight and portable and works on top of UDP, with optional support for reliable packets. It is easy to use, the API is low-level and with little performance overhead. You have a high degree of control over the memory management, which could be good if networking is a bottleneck for you and the malloc/new implementation you use performs badly under multithreading.
It would not be that hard to implement your high level thread “optimally”, since there is optional support for blocking receive and the library is a “library” and not a framework therefore you are the decision maker instead of the library.
Perhaps you can have a look at http://www.pt-framework.org/
Old question, but for C++, BSD style synchronous sockets this is about as minimal baggage wrapper as you can find
http://code.google.com/p/ting/source/browse/trunk/src/ting/net/
It does come with exceptions. You could make a bit more lightweight one as a header-only template library, and maybe make exceptions optional, but that would change the API a bit
POCO network classes are quite similar, but do require more dependencies from other parts of the Poco lib
I'm personally creating my own AsIO wrapper for both TCP and Serial sockets, and I started by reviewing the following tutorial:
https://www.gamedev.net/blogs/blog/950-they-dont-teach-this-stuff-in-school/
and
https://objectcomputing.com/resources/publications/mnb/multi-platform-serial-interfacing-using-boost-a-gps-sensor-and-opendds-part-i/
I found the first one very useful and simple to understand.
C++CSP2
Used it loved it. Stable and powerful
Related
I'm writing a distributed system wherein each node interfaces with local applications via some RESTful API, supports extensions and runtime customization, etc. It's a bit like an Enterprise Service Bus over the wide area, but with a lot else going on which is not related to the question at hand.
I've read a little about both MPI and Asio - originally I was set on Asio, but then I found MPI, and now again I'm thinking Asio is the better solution for me. MPI seems to provide a lot I don't need and a higher level of abstraction than I want - for example, I only need point-to-point communication, and it is important to me to be in control of when and what data is transmitted. (e.g. I have already designed a packet structure that I would conform to ideally)
So my primary question: it is worth it to start from a lower level with Asio, or should I try to graft MPI onto what i'm looking for? Further, are there 'skeleton applications' available which use MPI or Asio which would aid development? (Actually I am 100% new to C++.. ;) Or, does it make sense to use them in tandem?
For more perspective, maybe it's worth noting that I already have implemented the bulk of this project in Perl using Perl Object Environment, which itself is just an asynchronous event system with a ton of networking libraries.
Also, if it makes a difference, I would ideally use threads for this.
Honestly though I have not used Boost at all yet, as I hinted above, so any input is appreciated.
I should start by saying that I know nothing about Asio, but from the 2 minute scan of the website and the description of your problem, it sounds like while either would probably work for you, Asio might be simpler. MPI is really designed less for general purpose network communication and more for running applications where the set of processes and applications is a little more static. While it provides a client/server style interface if desired, it's not the main focus of the library.
MPI is also more difficult to use if you already have a packet structure designed. MPI is great for abstracting away the need to worry about packets, location of processes, etc. but if you've already taken all of that into account in you application, you have already done the hard work.
There have been at least one other discussion of Asio vs. MPI that you can take a look at (For distributed applications, which to use, ASIO vs. MPI?) to get more opinions too.
I am looking to write a server application in C++ that is meant to handle tens of thousands of clients simultaneously. It should run under Windows and Linux. I have been looking around for frameworks and libraries and have come across Boost Asio, which seems like a highly mature and widely used alternative. I just have trouble wrapping my head around strands/thread pools, mainly because of the millions of templates. My background is mainly in C, so am not really used to the template mess that Boost in general seems to be full of. I tried to find someone to develop a relatively thin wrapper around Boost Asio that would take care of the threading/synchronization aspect using strands, bind and the like, but have been unable to find someone yet who can do it within my budget (2 or 300 US dollars).
Can any of you recommend any other libraries that scale as well as Boost Asio (e.g. with IOCP on Windows and epoll on Linux etc), or a source where I might find skilled Boost developers looking for smaller freelance jobs?
Thanks very much in advance for any help.
Kind regards,
Philip Bennefall
Best 4 choices i know
I really like zeromq.. but libuv seems interesting.. (libev and libevent are very nice too)
zeromq
libevent (as said)
libev
libuv (Its purpose is to abstract
IOCP on windows and libev on Unix systems and it is node.js network layer)
ACE is the framework you are looking for. Even boost Asio is just an implementation of Proactor pattern, which was introduced by Douglas C. Schmidt. He is best known as the author of POSA Vol.2 and the creator of ACE framework.
The Boost.Asio library offers side-by-side support for synchronous
and asynchronous operations ... based on the Proactor design pattern
[POSA2].
Although it is a cross-platform C++ network framework and uses template,
just simple template is used. (or not at all)
My background is mainly in C, too, and I don't like Boost's massive template-programming style. However, ACE wasn't like that.
Try libevent on for size. Its whole raison d'etre is to address the C10K problem. I'd say it's probably more lightweight than boost.
Try Pulsar Server Framework. Main benefit is it is built over libuv network library (used by node.js) that uses asynchronous I/O based on event loops.
It’s perfectly scalable. You can just go adding servers as your user base increases.
It is designed to work with server farm.
Highly configurable and easy to use
Currently it has been built for Windows x64 server.
I'm trying to implement my own IRC client as a personal proejct and I realized I needed a way to read and write from the socket at the same time. I realized I could have a reading thread which reads from the socket in the background and puts data in a queue and I could have another thread which writes data from a queue to the socket. However I have no idea on how to start with multithreaded programing or how to do it with c++. Where do I go from here?
For C++ threads, boost::thread (which is the basis for the upcoming std::thread) is the best way to go. That said, while threads might be the correct solution for your particular case, I just wanted to throw it out there that select and non-blocking sockets are a common approach to interleaving the reading/writing and writing of multiple sockets without the need for threads. The boost::asio library wraps the functionality of select and non-blocking sockets in a cross-platform, C++ manner.
It's specific to C and *nix, but I can't think of a better starting place than Beej's Guide to Network Programming. "You will learn from the Jedi Master who instructed me."
You'll learn the basics of reading and writing to sockets, and more importantly, that multi-threading isn't necessarily the right answer.
I would suggest using Qt Threading. It is highly documented with really excellent sample code on almost every feature. Plus they are LGPL licensed now and will run on most every platform and include the source code with the binaries. They also have very good network supoort.
Whatever way you choose, make sure that they have good documentation and samples
I'd suggest looking at the POCO libraries. In my opinion they are easier to get on with than boost and have excellent documentation. These libs provide great frameworks for writing multithreaded networking code. You can learn a lot from them and get up and running pretty quickly.
I suggest ACE. It has portable abstractions for many operating system functions (*nix, Windows etc): BSD sockets, Threads, Mutexes, Semaphores etc - write once compile anywhere (See ACE_OS namespace of ACE).
It has a lot of network application patterns you can use (ACE_Reactor would be good for the beginning) but you can use the portable abstractions of the BSD functions (socket, send, recv, close, select - they are enough for your IRC client)
As previously mentioned boost is also an option and usually any cross-platform library providing portable abstractions for each operating system (I can think of wxWidgets, qt for the graphical part - if you want to do this).
And one advice: do not use threads unless you really need to. They are not as easy as it seems.
When referring to the network communication I believe that what you want to do is easily achievable in a single threaded application(ACE_Reactor helps you a lot here but you are free to use the BSD socket functions). First understand how sockets work, then - if you want to - understand how the reactor makes use of sockets in its network application patterns(ACE_Reactor works in conjuction with ACE_Event_Handler objects).
Hope it helps!
I'm looking for suggestions about choosing a portable way to achieve local IPC in a robust way, since i'm new to C++ and would like to avoid common pitfalls of fiddling with shared memory and locks; therefore I was thinking about message-passing style ipc.
I was planning to use qt for other reasons anyway, thus i took a peek to Qt ipc options.
if i understand correctly qt doesn't offer a completely portable message-passing ipc feature. it can use d-bus, but using it on windows would be a problem. other ways are limited to embedded linux platforms (and i would like to port this thing to AIX).
I could not find a "signal and slots" or message-passing style implementation that uses QSharedMemory and QSystemSemaphores
Thus: Am I limited to implement a feature on QSM/QSS?
what other options could i study?
posix pipes? protocol buffers? boost queues and messages ?
I'm considering to release the code under LGPL/GPL style license, does this rule out protocol buffers or boost libs?
please, again, the interface must be simple and newbie-proof (otherwise i definitely will screw up things big time for sure :) ), and so should the serialization/deserialization of types, error handling and resource disposal.
Take a look at Boost.Interprocess which provides a lot of IPC functionality. I have used the interprocess message_queue that provides a pretty clean and easy way to do what I think you want to do.
You can use QLocalSocket and QlocalServer for IPC too.
Those two classes are really easy to use and they can be implemented ~almost the same way as you would using Qt TCP socket client/server.
You can take a look at some of these youtube videos:
QTCPServer - a basic TCP server application
QTcpServer using multiple threads
(Almost the sames principles would apply for "Local" server/client instead of "TCP")
As Qt 5.9, there is module which is currently under technology preview name QtRemoteObjects which provides Qt native IPC for QObjects, its easy to use and could be used to share signal/slots and also models between two processes.
Its works well for Linux, Windows and android
What is the best way to use sockets on the Windows platform?
Basic sockets I guess, TCP/IP.
Maybe for a chat client, or just for learning.
Could someone give me an example of WININET usage?
maybe ftpgetfile()
That is a very broad question, and depends a lot on your needs.
What level do you need? HTTP/FTP? Or "just sockets" for your own protocol? What kind of performance do you need (amount of connections, expected speed)?
If you choose to go raw API, you should generally stay away from WSAAsyncSelect since performance is abysmal above "a few" concurrent connections. Blocking sockets and thread-per-socket isn't too hot either. WSAEventSelect is slightly tricky, but gets the job done nicely (µtorrent handles a lot of concurrent connections this way). Fancypants really-high-load would be I/O Completion Ports. You could also look into boost ASIO for some portability.
If you want to use standard protocols like HTTP/FTP, check libcurl. Or, for lesser needs and smaller overhead, the standard Windows WININET functions (has a lot of restrictions though).
For using WinINet functions, try starting here - might not be a sample, but at least gives you enough stuff to google for ;)
For basic client server application with TCP/UDP winsock should be sufficient.
Do you mean asynchronous I/O model on windows?
There are select, WSAAsyncSelect, WSAEventSelect, Overlapped I/O, I/O Completion Port, also you may want to use Libevent and Boost Asio which are both cross platform.
WinInet examples you could find in msdn or codeproject.con
Ways to use you could find in nice platofrm independed lib - boost::asio
If you are looking to use this as a learning experience I would also look at ACE. A C++ cross platform framework that implements a lot of the patterns discussed in Patterns for Concurrent Network and Networked Objects. The author has also written on ACE as well (see here).