For quite some time now, I've been trying to implement a multi-threaded or forked TCP server to perform the following action:1) Listen for new connections on all ip addresses on a specific port.2) Wait for a new connection to arrive3) When a new connection coms in, fork or thread to free up the listening process so it can go back to #2.When handling a client after it's been forked/threaded4) Get the connected client's ip address.5) Perform some in-house processing;6) Read the data sent from the client (checking for http connections)7) Perform some more processing;8) Write some data back to the client based on the above processing9) Close the socket/thread/forkI've tried implementing an solution similar to the multi-threaded example show here http://perl.active-venture.com/pod/p...-sockets.html; as well as looking at the CPAN solutions Net:aemon and POE::Component::Server::TCP but these don't seem to give me the information needed.The active-venture solution provides me with what I need, but randomly exits without reason/error and when attempting to change the 'for' loop to a 'while' loop, it keeps throwing up different errors.
I ran into an inconsistency in handling timers (VTALRM) between AMD and intel platforms with threads. My understanding was that the timers are per process. I discovered I must call setitimer in the thread on intel though. AMD allows me to make the setitimer call once in the main thread as expected. The code below demonstrates the issue. I must add the code in the INTEL define for it to work properly on intel cpu's. Am I missing something dumb??
I'm trying to add local sockets in my multi-threaded application in order to exchange data between threads. The only problem I got is that most of the information available on the net is related to internet oriented socket programming whileI want to perform local connections. got a thread that does the sniffing via libpcap. And I would like that thread to send each captured packet to a second thread that will analyse the packetof the thread implementations is written in separate .h file.Or maybe there is a more effective method of exchanging data between threads
I am implementing a proxy server in c++. It is multithreaded(posix).Used CPU : Xeon(8core) Thread number : 8 One main thread, and other 7 thread created by the main thread. The main thread always listen to ports. When the main thread gets a client data it push the request in a queue[there are one queue(total 7) for each thread] based on ip and then give a signal to the appropriate thread. Then that thread gets the request from it's queue and process data and then forward the data to a appropriate destination.
There is another important thing, I assign each thread excluding the main thread to individual core by using affinity.The main thread listens to 5 ports. Test environment: We run the server. The client sends audio data at a particular rate.
1. The main thread CPU usage gets overloaded (above 80%) after a certain load from client.
2. Other cores remain about 0-10%.
The thing is that we want to distribute the load among all the cores equally by multithreading. But how can we do this ? Can the listening task of ports also be distributed ? I need an efficient algorithm for load balancing among threads. The data sent and receive rate of server is about 8.5MB/s. How can we improve this ? we are using gigabit LAN card. When the server only receive data from client it can receive data above 80MB/s. But when it both receives and sends data simultaneously it only manage upto 8.5MB/s.
Using Ubuntu server 10.04.2 64-bit all up to date.
I am running multi-threaded processes. These use OpenMP in my own code and the multi-threaded ACML maths library. When run in the foreground, everything is fine i.e. if I have set
export OMP_NUM_THREADS=8
then when I start all 8 cores are in use and things whizz along. However, when running overnight and logged out using e.g. 'at now + 1 minute' then the command, I am only getting about 130% CPU and it slows down accordingly. I have tried renice'ing and calling from within a bash script in case sh is doing something odd but nothing seems to solve it. I am sure that in the recent past this wasn't the case.
The libraries being used are shared versions in case that might have any bearing.
I have a centos 5.5 machine. I have forwarded both port 22 and 8080 on my router. I can connect on 22 via telnet ip 22 and even can remotely login into the machine. The problem when I start my java listener program which is listening on 8080 it cant not establish any connection (via telnet ip 8080). I have even add this into the iptables too -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 9000 -j ACCEPT. I have disabled the SELINUX too.
I have a gateway server which is currently listening for TCP/UDP packets and authenticating clients if their details IP/MAC is known.
I have a couple of clients who's network equipment sends ICMP pings to a remote site to determine internet connectivity and I'm missing those resulting in the client's device not logging in.
Is there some way that I can write a listener similar to a listener for TCP/UDP sockets which will listen to ICMP packets and pick up the IP and MAC address of the sender upon which I can perform processing on?
This is the result of reading lots of advice on this forum and elsewhere--thought I'd put it into one post for people's convenience. Picked up the latest tarball at [URL]... Unpacked the tarball with tar -zxvf nameofball.tar.
Loaded the following packages that it depended on: sudo apt-get install build-essential libtagc0-dev gperf libunistring-dev pkg-config zlib1g-dev libconfuse-dev libavahi-client-dev libsqlite3-dev libavcodec-dev libavformat-dev libswscale-dev libmxml-dev libevent-dev libavl-dev libantlr3c-dev libgcrypt11-dev libflac-dev libogg-dev libtagc0-dev libasound2-dev .
Ran ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --enable-flac --enable-musepack. Fix any errors that show up by tracking down a dependency that I hadn't listed above. Keep on running until it has no errors. Then make; sudo make install. I had installed checkinstall, so I ran make; sudo checkinstall -D instead.
Then to set up the system:
Code: #make an init.d script (the script I used is at the end of this post) sudo -e /etc/init.d/forked-daapd sudo chmod +x /etc/init.d/forked-daapd sudo update-rc.d forked-daapd defaults
i'm a college student studying pc programing, and i was given today a special work and i have to program using miranda... which i've never used it >.< can anyone give me a hand to where to download, how to compile, and a simple tutorial for making a simple program or something?
I don't have any problem when I'm communicating with one client. The problem starts when I connect another client.The server eventually ignores the older clients and responds only to the latest one.The working mechanism is simple: Accept connections and print messages received from multiple clients.
im trying to build a simple program for my C programming class, this is the source code
#include <stdio.h> int main() { int length, width, length, height, area, perimeter; perimeter = width + length + height; area = width * length + heigth;
[Code]...
i dont see any error (you might)but every time i run it it runs but after it asks me to input for the width i do it but it doesn't take me to the length, it just stays blank until i input another value in the same place for the width, it asks me for 4 inputs in total i don;t know why, and after i run it different times it gives me different values for the perimeter and are. how can I fix this?
my friends with taste in good music players! Amarok 1.4 has a new fork called Pana! Homepage: [URL]..Current build with visualization support (which is not enabled in the build from the PPA). [URL]..please also install these packages:
I have forwarded both port 22 and 9000 on my router. I can connect on 22 and remotely login into the machine. The problem when I start my java listener program which is listening on 9000 it cant not establish any connection. I have even add this into the iptables too -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 9000 -j ACCEPT. I have disabled the SELINUX too. What else must I do to make it work any suggestion please?
I will be relocating to a permanent residence sometime in the next year or two. I've recently begun thinking about the best way to implement a home-based network. It occurred to me that the most elegant solution might be the use of VM technology to eliminate as much hardware and wiring as possible.My thinking is this: Install a multi-core system and configure it to run several VMs, one each for a firewall, a caching proxy server, a mail server, a web server. Additionally, I would like to run 2-4 VMs as remote (RDP)workstations, using diskless workstations to boot the VMs over powerline ethernet.The latest powerline technology (available later this year) will allow multiple devices on a residential circuit operating at near gigabit speed, just like legacy wired networks.
In theory, the above would allow me to consolidate everything but the disklessworkstations on a single server and eliminate all wired (and wireless) connections except the broadband connection to the Internet and the cabling to the nearest power outlets. It appears technically possible, but I'm not sure about the various virtual connections among VMs. In theory, each VM should be able to communicate with the other as if it was on the same network via the server data bus, but what about setting up firewall zones? Any internal I/O bandwidth bottlenecks? Any other potential "gotchas", caveats, issues? (Other than the obvious requirement of having enough CPU and RAM).Any thoughts or observations welcome, especially if they are from real world experience in a VM environment. BTW--in case you're wondering why I'm posting here, it's because I run Debian on all my workstations/servers (running VirtualBox as a VM for Windows XP on one workstation).
I can call this routine and it works fine when I enter a valid name for $PROJ. If I enter an invalid name it goes to the else block and prints the statement. However, it does not call itself. Instead the script just exits.I've googled 'perl recursive subroutines' and the example don't appear to be doing anything different.
I have been looking at: ut a lot of it is to do with files and numerical comparisonswhat would be the bash equivalent of:if (http isin $2) { do something }
I am trying to create a function that takes a pair of a high and a low limit, and returns an arbitrary number between them. Below is my attempt to create a function that accomplishes this by checking to see if they are equal, and if not, subtracts a very small number from the high limit and returns the result.
So I have built a program that takes a picture from two cameras every second and converts them both to jpeg format. The problem is that currently it takes ~2 seconds to convert a single raw photo to jpeg format, thus every second I add another raw photo (30 MB) to ram waiting to be converted to jpeg. So, theoretically the conversion to jpeg is running on a single core with hyperthreading, would I see better performance running the exact same process (a program pulling from a queue and converting to jpeg) running as a single process, or two concurrent processes? (both processes running on the same core, (so 1 thread on one clock cycle, the other on the other... (or one thread running on 1 core and the other on another core. What other steps would you take to improve the performance so there would no longer be a race condition?
I do a lot of scientific work - mainly in C/C++ but want to do some of the calcs in python, however I am finding it a problem with the lack of dimensionality. I frequency have a list of n particles and a multi-dim array for each particle and want to be able to access directly any component with ease. How best to go about this...
my prop = [n][x][y][z]
I might need a particular value and then to update that. I do not want to have to deal with lists etc etc as this feels rather cumbersome, adding, removing etc. There must be an easy way.
I need to sort it by array[ $key ][ 2 ] so that it is sorted like so: Code: Array ( [0] => Array ( [0] => Eleven [1] => NumberEleven [2] => 11 ) [1] => Array ( [0] => AnotherEleven [1] => Eleven,Again [2] => 11 ) [2] => Array ( [0] => Twelve [1] => NumberTwelve [2] => 12 )
I've looked at the php array docs the closet thing I found was array_multisort which won't work for my above requirements, does anyone have any insight to how to sort this way?
I am parsing through XML documents with a PHP script and creating an array because, as far as I know, I can manipulate arrays better than the features DOM gives me. That part is not as important, though. The array it produces though is multi-dimensional, but somewhat inconsistent. If I have the following XML:
To call the first bookmark from the first domain, it would be: PHP Code: $array['domains']['domain'][0]['bookmarks']['bookmark'][0] To call the first bookmark from the second domain, it would be: PHP Code: $array['domains']['domain'][1]['bookmarks']['bookmark']
The problem is, I want to simply call bookmarks through a simply 'foreach()' or 'for()' function and the lack of consistency might be a problem, but the fact that some levels have a '0' array key and others do not is causing a problem.
we need to log web access of a certain set of users for analysis. We decided to setup a proxy server which just logs all the requests but does not do anything else like caching/access control etc.All users will be using a fixed set of computers and hence we can redirect their requests to the proxy. I came across Squid, but found it to be too heavy for our requirements. Is there any other proxy-server software that is good enough for what we want or is Squid the only way?
This is probably hopelessly ambitious as I'm not a C or C++ programmer (I normally like to stick to scripting languages like BASH or Perl). Basically I'm looking on good advice to get me started with writing a Application Dock with the functionality of the OSX dock but without the overly flamboyant graphics that have characterised the Linux versions.At the moment the closest I've found to what I would like is bbdock. However it falls well short of the functionality of what I would like.
What bbdock does is read a file to create an icon for the openbox dock/fluxbox slit/wmaker whatever that launches an application when first clicked, shows an little arrow when the application is running, and brings the application to the fore when clicked once running.Here's a screenshot of it doing just that.The drawback to bbdock is that it doesn't really look for running applications, only those launched from bbdock. So for example it wont notice if I've launched an instance of pcmanfm from the openbox menu. And therefore it obviously also doesn't add icons for other applications that are running.
What I would like to be able to do is detect new running applications and add a bbdock icon for them. Also to detect if an application already with a shortcut has been run and update it's status to show it's open. Probably have an up and down arrow to move the icons up and down when there are too many to fit on the screen. None of the above needs fancy animation. The fade to gray effect used by bbdock is quite nice and could probably be augmented with a fade in and out to grey to represent another action, say fading to grey and back when launching and greyed when iconified.So, my question is what do I need to get started doing this? Am I best using the pretty outdated bbdock wmaker dockapp style? What functions and libraries am I likely to need to achieve the effects I want? Are there any examples of how to monitor running applications (well windows and figure out what constitutes a new application) that I could look at for inspiration. Is there anyone who's into C++ for linux who would be interested in helping me out to get this small project working?
I want to create simple webcam effects filters. I am only interested in doing relatively simple image processing like blurring or averaging the color. I would like to create the filters in either C or Python.
So before I dive into using Gstreamer or V4L I wanted to ask the forum if they have had any experience with webcam development?
