Search Results

Search found 16706 results on 669 pages for 'non blocking io'.

Page 3/669 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • error on connecting to the server : socket io is not defined

    - by max
    i know there's been couple of question about the same problem , i've already check them . i have very simple node.js chat app i have a server running on 8000 port and it works fine my client pages are html , they are running on apache and i'm using socket.io to connect them to the server and it works fine on the local host but when i upload the app on the server i keep on getting this error in the firebug io is not defined var socket = io.connect('http://atenak.com:8000/'); or sometimes it doesn't show that but when i try to broadcast message from cliend i get this error : socket is undefined socket.emit('msg', { data: msg , user:'max' }); the only difference is i've changed the localhost with atenak.com ! here is my html code var socket = io.connect('http://atenak.com:8000/'); var user = 'jack'; socket.on('newmsg', function (data) { if(data.user == user ) { $('#container').html(data.data); } }); function brodcast(){ var msg = $('#fild').val(); socket.emit('msg', { data: msg , user:'max' }); } </script> </head> <body> <div id="container"> </div> <input id="fild" type="text"> <input name="" type="button" onClick="brodcast();"> </body> i have included the sockt.io.js and server is running ok which means socket.io is installed on the server here is the live page http://atenak.com/client.html

    Read the article

  • Debugging IO limitation

    - by Martin F
    I have a Fedora box with some severe IO limitations which I have no idea how to debug. The server has a Areca Technology Corp. ARC-1130 12-Port PCI-X to SATA RAID Controller with 12 7200 RPM 1.5 TB disks and a Marvell Technology Group Ltd. 88E8050 PCI-E ASF Gigabit Ethernet Controller. uname -a output: 2.6.32.11-99.fc12.x86_64 #1 SMP Mon Apr 5 19:59:38 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux The server is a file server running Nginx with the stub status module enabled, so I can see the current amount of connections. The problem present itself when I have a high number of simultaneous connections in a writing state. Usually around 350, at this very moment it's at 590 and the server is almost unusable and stuck at 230mbit/s. If I run stop and hit 1 to see CPU core usages I have all 4 cores with around 99% io wait, if I run iotop the nginx workers are the only processes producing any read load, currently at around 25MB/s. I have each of the workers bound to their own core. Initially I figured it was just the disks being bugged. But I've run fscheck and smartmontools checks and found no errors. I also ran an iozone test which you can see the result of here: http://www.pastie.org/951667.txt?key=fimcvljulnuqy2dcdxa Additionally, when the amount of connections are low I have no problem getting a good speed. If I wget over the local network it easily hits 60MB/sec. Right now I just tried putting a file in /dev/shm, then I symlinked a file from the public dir to it and used wget over the local network and only got 50KB/s. Also, if I try to cp /dev/shm/test /root/test it quickly copies around 740MB and then slows down HEAVILY. Again with iotop reporting 99% iowait. I'm not really sure how to go about figuring out what the problems are. It could be a natural disk limitation but then the file from /dev/shm ought to transfer so it seems there's a network limit, but that's fine when there's not many connections. Perhaps it's a TCP stack problem but I really have no idea how to check that. Any suggestions on how to proceed with debugging would be very welcome. If additional information is required then let me know and I'll try to get it. Thanks.

    Read the article

  • Will it be possible to use a non-pae kernel in 12.10

    - by Roland Taylor
    I know that Ubuntu +1 questions are frowned upon, but this I believe is a fair exception. Currently I have 2 systems running Ubuntu 12.10, and one of them has a Pentium M that doesn't support PAE (strange I know, but true). This has meant in the past that I had to rely on a custom iso to install Ubuntu a similar system,and so this time I went with Xubuntu 12.04. My question is 2 fold, but really one question: Is it/will it be possible to install a non-pae version of the 12.10 kernel from the standard repositories? If no, how can I get such a kernel? (Is there a PPA with such a kernel available?). NB: Before anyone suggests that I just install this package: http://packages.ubuntu.com/quantal/linux-image-generic, please note that this comes with PAE enabled. P.S. Yes, I have Googled. I haven't found the answer.

    Read the article

  • Pancake.io Is a Dead Simple Way to Host a Web Site from Your Dropbox Account

    - by Jason Fitzpatrick
    Pancake.io is a web-based app that makes it dead simple to use your Dropbox account as as simple web host. Signup for an account and Pancake.io creates a folder in your Dropbox. You can modify the page in one of two ways: you can simply put files into the folder and use the simple template provided by Pancake.io to share them or you can edit the template (located in the Pancake.io folder) to customize the page. Hit up the link below to read more about Pancake.io and take it for a test drive. Pancake.io [via ReadWriteWeb] HTG Explains: How Hackers Take Over Web Sites with SQL Injection / DDoS Use Your Android Phone to Comparison Shop: 4 Scanner Apps Reviewed How to Run Android Apps on Your Desktop the Easy Way

    Read the article

  • ubuntu 12.04 non-pae kernel 3.5.0-17-wt-nonpae

    - by volker
    ubuntu 12.04 non-pae kernel 3.5.0-17-wt-nonpae: installed this kernel on dell d505 (pentium M) under ubuntu 12.04. Runs slower than 3.2.0-33 and 3.2.0-030200. Is this to be expected? Could not install the kernel headers provided on the ppa: "dependencies cannot be fullfilled: linux-headers-3.5.0-17". After installing the kernel image, Synaptic offered me to install linux-headers-3.5.0-18 and linux-headers-3.5.0-18-generic (which could be installed successfully). volker

    Read the article

  • IE8 blocking JavaScript Cookies

    - by ossreleasefeed
    Hey there folks, Here is one that is throwing me for a loop. I am trying to set a simple cookie that has one name:value pair on IE8. Tested on FF and it works fine. IE8 keeps blocking it. I have read about the P3P stuff and created a basic P3P doc, no errors reported by the IBM tool, and added the following on all pages: <meta http-equiv="P3P" CP="CAO DSP COR PSDa CONi TELi OUR STP COM NAV"><link rel="P3Pv1" href="/w3c/p3p.xml"></link> The code I use to set the cookie is as follows: function setCompatibilityCookie(c_name, value, expiredays) { var exdate = new Date(); exdate.setDate(exdate.getDate() + expiredays); document.cookie= c_name + "=" + escape(value) + ((expiredays==null) ? "" : ";expires=" + exdate.toUTCString());} Any ideas why IE8 keeps blocking me from setting this cookie? Thank you, Schalk

    Read the article

  • How does Linux blocking I/O actually work?

    - by tgguy
    In Linux, when you make a blocking i/o call like read or accept, what actually happens? My thoughts: the process get taken out of the run queue, put into a waiting or blocking state on some wait queue. Then when a tcp connection is made (for accept) or the hard drive is ready or something for a file read, a hardware interrupt is raised which lets those processes waiting to wake up and run (in the case of a file read, how does linux know what processes to awaken, as there could be lots of processes waiting on different files?). Or perhaps instead of hardware interrupts, the individual process itself polls to check availability. Not sure, help?

    Read the article

  • Filtering serial port io

    - by mr odus
    I am currently working on a project where I communicate with hardware via a com port on its respective pc(win xp or 7) It is a fairly large project and sifting through the log file can be a bit of pain. This is my current setup. I use putty to do the actual serial communication, and write it to a log file. Then using MinGW Msys I filter it using tail -f "puttyLog" | grep -i "search term" Is there a better way to do this? I mean specifically filtering the input in realtime. Not that mine is terrible, but it still involves having to read from a log and sometimes there have been hangups where it will be delayed for a minute or 2. I have used software in the past with a main io window and then internal filter panels, but can no longer remember or find it.

    Read the article

  • Continual Professional Development - proving new skills to non-technical employers

    - by Tom
    Background I work in a non-IT based company, as a professional software developer, building a large scale internal database system. I am fortunate to have a fairly senior position within the company, and have been working here for around 4 years. Often I get asked by management "how do you learn new things?". To be honest, I don't know how to answer this. Over the last 6 months, I've really gotten my teeth into some new techniques and technologies to make my level of coding far better and hopefully improve the quality of the software. Even if it's just refreshing my skills on things I've learnt already. Like last week I dived into some complex XLinq and TPL code (.net). Nothing revolutionary, but I feel like I am a bit better than before. Question The question is, how do I prove this to my employer? It'd be nice to be able to put this on paper. Possibilities I could: Keep a journal of what I've learnt - keeping the technical bits in (nobody would understand or care, but it's better than them being omitted) ???? (I've run out of ideas already) Any ideas? Thanks, Tom

    Read the article

  • Tracking download of non-html (like pdf) downloads with jQuery and Google Analytics

    - by developerit
    Hi folks, it’s been quite calm at Developer IT’s this summer since we were all involved in other projects, but we are slowly comming back. In this post, we will present a simple way of tracking files download with Google Analytics with the help of jQuery. We work for a client that offers a lot of pdf files to download on their web site and wanted to know which one are the most popular. They use Google Analytics for a long time now and we did not want to have a second interface in order to present those stats to our client. So usign IIS logs was not a idea to consider. Since Google already offers us a splendid web interface and a powerful API, we deceided to hook up simple javascript code into the jQuery click event to notify Analytics that a pdf has been requested. (function ($) { function trackLink(e) { var url = $(this).attr('href'); //alert(url); // for debug purpose // old page tracker code pageTracker._trackPageview(url); // you can use the new one too _gaq.push(["_trackPageview",url]); //always return true, in order for the browser to continue its job return true; } // When DOM ready $(function () { // hook up the click event $('.pdf-links a').click(trackLink); }); })(jQuery); You can be more presice or even be sure not to miss one click by changing the selector which hooks up the click event. I have been usign this code to track AJAX requests and it works flawlessly.

    Read the article

  • Possible disk IO issue

    - by Tim Meers
    I've been trying to really figure out what my IOPS are on my DB server array and see if it's just too much. The array is four 72.6gb 15k rpm drives in RAID 5. To calculate IOPS for RAID 5 the following formula is used: (reads + (4 * Writes)) / Number of disks = total IOPS. The formula is from MSDN. I also want to calculate the Avg Queue Length but I'm not sure where they are getting the formula from, but i think it reads on that page as avg que length/number of disks = actual queue. To populate that formula I used the perfmon to gather the needed information. I came up with this, under normal production load: (873.982 + (4 * 28.999)) / 4 = 247.495. Also the disk queue lengh of 14.454/4 = 3.614. So to the question, am I wrong in thinking this array has a very high disk IO? Edit I got the chance to review it again this morning under normal/high load. This time with even bigger numbers and IOPS in excess of 600 for about 5 minutes then it died down again. But I also took a look at the Avg sec/Transfer, %Disk Time, and %Idle Time. These number were taken when the reads/writes per sec were only 332.997/17.999 respectively. %Disk Time: 219.436 %Idle Time: 0.300 Avg Disk Queue Length: 2.194 Avg Disk sec/Transfer: 0.006 Pages/sec: 2927.802 % Processor Time: 21.877 Edit (again) Looks like I have that issue solved. Thanks for the help. Also for a pretty slick parser I found this: http://pal.codeplex.com/ It works pretty well for breaking down the data into something usable.

    Read the article

  • io operations in compilers

    - by Aastha
    How are constructs of io operations handled by a compiler? Like the RTL mapping for memory related operations which is done in a compiler at the time of target code generation, where and how exactly is the same done for io operations? How are the appeoaches different for processors supporting MMIO and I/O mapped I/O? Are there any optimizations done for the io operations in compilers?

    Read the article

  • Multi Player game using Nodejs and Socket IO

    - by Kishorevarma
    I am trying out multi player racing game using Node and Socket IO ,express . So I have tried simple example to see the latency between node server and the clients. I have a draggable image in client . when I move the image ienter code heren one client ,it has to move in all clients. so basically when I am moving the image I am sending the image position to the node server in a json format , then from there I am broadcasting to all clients. there is a ~approx 300ms latency from the time. following are the results. Client 1 sending data to server at : 286136 (timestamp) Server received at : 286271 Client2 received data at : 286470 Client3 received data at : 286479 Client4 received data at : 286487 Client5 received data at : 286520 the latency between move from client1 to client5 is 384ms. its too hight for a racing game .. here is my server code. var app = require('express').createServer(); var io = require('socket.io'); var http = require('http'); var http_server = http.createServer(); var server = http.createServer(app); server.listen(3000); var socket = io.listen(server,{ log: false }); socket.sockets.on('connection', function (client) { client.on('message', function (data){ console.log("data arrived to server",new Date().getTime()); // Below both statements are giving same latency between the client 1 and client 5 client.broadcast.emit('message',data); //socket.sockets.emit('message',data); }); }); 1) Is there any way to optimize the server code to reduce the latency? 2) is this expected latency using node and websockets ? 3) is socket io can't broadcast the data asynchronously (I mean at a same time) ? Thanks Kishorevarma

    Read the article

  • A non-blocking server with java.io

    - by Jon
    Everybody knows that java IO is blocking, and java NIO is non-blocking. In IO you will have to use the thread per client pattern, in NIO you can use one thread for all clients. Now my question follows: is it possible to make a non-blocking design using only the Java IO api. (not NIO) I was thinking about a pattern like this (obviously very simplified); List<Socket> li; for (Socket s : li) { InputStream in = s.getInputStream(); byte[] data = in.available(); in.read(data); // processData(data); (decoding packets, encoding outgoing packets } Also note that the client will always be ready for reading data. What are your opinions on this? Will this be suitable for a server that should at least hold a few hundred of clients without major performance issues?

    Read the article

  • Handling file upload in a non-blocking manner

    - by Kaliyug Antagonist
    The background thread is here Just to make objective clear - the user will upload a large file and must be redirected immediately to another page for proceeding different operations. But the file being large, will take time to be read from the controller's InputStream. So I unwillingly decided to fork a new Thread to handle this I/O. The code is as follows : The controller servlet /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse * response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub System.out.println("In Controller.doPost(...)"); TempModel tempModel = new TempModel(); tempModel.uploadSegYFile(request, response); System.out.println("Forwarding to Accepted.jsp"); /*try { Thread.sleep(1000 * 60); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); }*/ request.getRequestDispatcher("/jsp/Accepted.jsp").forward(request, response); } The model class package com.model; import java.io.IOException; import java.util.concurrent.ExecutionException; import java.util.concurrent.Future; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.utils.ProcessUtils; public class TempModel { public void uploadSegYFile(HttpServletRequest request, HttpServletResponse response) { // TODO Auto-generated method stub System.out.println("In TempModel.uploadSegYFile(...)"); /* * Trigger the upload/processing code in a thread, return immediately * and notify when the thread completes */ try { FileUploaderRunnable fileUploadRunnable = new FileUploaderRunnable( request.getInputStream()); /* * Future<FileUploaderRunnable> future = ProcessUtils.submitTask( * fileUploadRunnable, fileUploadRunnable); * * FileUploaderRunnable processed = future.get(); * * System.out.println("Is file uploaded : " + * processed.isFileUploaded()); */ Thread uploadThread = new Thread(fileUploadRunnable); uploadThread.start(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } /* * catch (InterruptedException e) { // TODO Auto-generated catch block * e.printStackTrace(); } catch (ExecutionException e) { // TODO * Auto-generated catch block e.printStackTrace(); } */ System.out.println("Returning from TempModel.uploadSegYFile(...)"); } } The Runnable package com.model; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.ByteBuffer; import java.nio.channels.Channels; import java.nio.channels.ReadableByteChannel; public class FileUploaderRunnable implements Runnable { private boolean isFileUploaded = false; private InputStream inputStream = null; public FileUploaderRunnable(InputStream inputStream) { // TODO Auto-generated constructor stub this.inputStream = inputStream; } public void run() { // TODO Auto-generated method stub /* Read from InputStream. If success, set isFileUploaded = true */ System.out.println("Starting upload in a thread"); File outputFile = new File("D:/06c01_output.seg");/* * This will be changed * later */ FileOutputStream fos; ReadableByteChannel readable = Channels.newChannel(inputStream); ByteBuffer buffer = ByteBuffer.allocate(1000000); try { fos = new FileOutputStream(outputFile); while (readable.read(buffer) != -1) { fos.write(buffer.array()); buffer.clear(); } fos.flush(); fos.close(); readable.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("File upload thread completed"); } public boolean isFileUploaded() { return isFileUploaded; } } My queries/doubts : Spawning threads manually from the Servlet makes sense to me logically but scares me coding wise - the container isn't aware of these threads after all(I think so!) The current code is giving an Exception which is quite obvious - the stream is inaccessible as the doPost(...) method returns before the run() method completes : In Controller.doPost(...) In TempModel.uploadSegYFile(...) Returning from TempModel.uploadSegYFile(...) Forwarding to Accepted.jsp Starting upload in a thread Exception in thread "Thread-4" java.lang.NullPointerException at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:512) at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:497) at org.apache.coyote.http11.InternalInputBuffer$InputStreamInputBuffer.doRead(InternalInputBuffer.java:559) at org.apache.coyote.http11.AbstractInputBuffer.doRead(AbstractInputBuffer.java:324) at org.apache.coyote.Request.doRead(Request.java:422) at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:287) at org.apache.tomcat.util.buf.ByteChunk.substract(ByteChunk.java:407) at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:310) at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:202) at java.nio.channels.Channels$ReadableByteChannelImpl.read(Unknown Source) at com.model.FileUploaderRunnable.run(FileUploaderRunnable.java:39) at java.lang.Thread.run(Unknown Source) Keeping in mind the point 1., does the use of Executor framework help me in anyway ? package com.utils; import java.util.concurrent.Future; import java.util.concurrent.ScheduledThreadPoolExecutor; public final class ProcessUtils { /* Ensure that no more than 2 uploads,processing req. are allowed */ private static final ScheduledThreadPoolExecutor threadPoolExec = new ScheduledThreadPoolExecutor( 2); public static <T> Future<T> submitTask(Runnable task, T result) { return threadPoolExec.submit(task, result); } } So how should I ensure that the user doesn't block and the stream remains accessible so that the (uploaded)file can be read from it?

    Read the article

  • check if a domain is blacklisted / blocked

    - by Henry
    Some clients report to us that our site is not accessible through their internet connection. We suspect our site is wrongfully blocked by some security software/firewall/public blacklist. How can we verify that, other than trying them one by one? There are so many security software out there that it is not practical... Thx

    Read the article

  • Hide non printable characters in vim

    - by knittl
    Vim shows non-printable characters prefixed with a ^ (for instance ^@ for a NUL byte). I have a column based file containing both printable and non-printable characters which is difficult to read, since each non-printable character shifts all remaining columns one character to the right. Is there a way to hide non-printable characters or simply display a placeholder char instead? I also don't mind having every character be represented by two characters.

    Read the article

  • highlighting non-ascii text

    - by non-techie
    As a non-techie, I would really appreciate your help on this. I have some files (html) that need to be in pure ascii form to be properly processed. Since these files are produced by humans, every so often non-ascii characters sneak in. Often it is a stray " (curled variety) or something similar that is difficult to find and need to be removed. I have found text editors (eg. textmate) that can strip out all non-ascii characters, but I need to find one that can highlight where they are, rather than remove them (as I need to remove them from the source and not the html file). I hope this makes sense and appreciate any assistance you can provide. Thanks!

    Read the article

  • SQL Server 2005 Sleeping SPID blocking another SPID...

    - by user173552
    I find many sleeping process my SQL Server database and looks like one of those sleeping SPIDs is blocking another process, and that process is getting suspended too... Could some one please explain this... 1.) How can a sleeping process block another process? 2.) I see many sleeping process...is this normal? Thanks

    Read the article

  • how non-programmer become developer

    - by Sarang
    Every year there are different types of freshers getting recruited. But, our IT field is not only limited to IT Engineers & Computer Engineers. It is full of all different types of engineers. What is a way an engineer can be a proper developer ? I am asking this because, whatever engineering the student gone for, one can be shifted to IT development if he/she has some particular qualities within. What are those quelities required to be in a developer or required to be implemented to be developer ?

    Read the article

  • Semi-blocking Transformations in SQL Server Integration Services SSIS

    In a SSIS data flow, there are multiple types of transformations. On one hand you have synchronous and asynchronous transformations, but on the other hand you have non-blocking, semi-blocking and fully-blocking components. In this tip, Koen Verbeeck takes a closer look on the performance impact of semi-blocking transformations in SSIS. Can 41,000 DBAs really be wrong? Join 41,000 other DBAs who are following the new series from the DBA Team: the 5 Worst Days in a DBA’s Life. Part 3, As Corrupt As It Gets, is out now – read it here.

    Read the article

  • SQL Server IO handling mechanism can be severely affected by high CPU usage

    - by sqlworkshops
    Are you using SSD or SAN / NAS based storage solution and sporadically observe SQL Server experiencing high IO wait times or from time to time your DAS / HDD becomes very slow according to SQL Server statistics? Read on… I need your help to up vote my connect item – https://connect.microsoft.com/SQLServer/feedback/details/744650/sql-server-io-handling-mechanism-can-be-severely-affected-by-high-cpu-usage. Instead of taking few seconds, queries could take minutes/hours to complete when CPU is busy.In SQL Server when a query / request needs to read data that is not in data cache or when the request has to write to disk, like transaction log records, the request / task will queue up the IO operation and wait for it to complete (task in suspended state, this wait time is the resource wait time). When the IO operation is complete, the task will be queued to run on the CPU. If the CPU is busy executing other tasks, this task will wait (task in runnable state) until other tasks in the queue either complete or get suspended due to waits or exhaust their quantum of 4ms (this is the signal wait time, which along with resource wait time will increase the overall wait time). When the CPU becomes free, the task will finally be run on the CPU (task in running state).The signal wait time can be up to 4ms per runnable task, this is by design. So if a CPU has 5 runnable tasks in the queue, then this query after the resource becomes available might wait up to a maximum of 5 X 4ms = 20ms in the runnable state (normally less as other tasks might not use the full quantum).In case the CPU usage is high, let’s say many CPU intensive queries are running on the instance, there is a possibility that the IO operations that are completed at the Hardware and Operating System level are not yet processed by SQL Server, keeping the task in the resource wait state for longer than necessary. In case of an SSD, the IO operation might even complete in less than a millisecond, but it might take SQL Server 100s of milliseconds, for instance, to process the completed IO operation. For example, let’s say you have a user inserting 500 rows in individual transactions. When the transaction log is on an SSD or battery backed up controller that has write cache enabled, all of these inserts will complete in 100 to 200ms. With a CPU intensive parallel query executing across all CPU cores, the same inserts might take minutes to complete. WRITELOG wait time will be very high in this case (both under sys.dm_io_virtual_file_stats and sys.dm_os_wait_stats). In addition you will notice a large number of WAITELOG waits since log records are written by LOG WRITER and hence very high signal_wait_time_ms leading to more query delays. However, Performance Monitor Counter, PhysicalDisk, Avg. Disk sec/Write will report very low latency times.Such delayed IO handling also occurs to read operations with artificially very high PAGEIOLATCH_SH wait time (with number of PAGEIOLATCH_SH waits remaining the same). This problem will manifest more and more as customers start using SSD based storage for SQL Server, since they drive the CPU usage to the limits with faster IOs. We have a few workarounds for specific scenarios, but we think Microsoft should resolve this issue at the product level. We have a connect item open – https://connect.microsoft.com/SQLServer/feedback/details/744650/sql-server-io-handling-mechanism-can-be-severely-affected-by-high-cpu-usage - (with example scripts) to reproduce this behavior, please up vote the item so the issue will be addressed by the SQL Server product team soon.Thanks for your help and best regards,Ramesh MeyyappanHome: www.sqlworkshops.comLinkedIn: http://at.linkedin.com/in/rmeyyappan

    Read the article

  • What determines which Javascript functions are blocking vs non-blocking?

    - by Sean
    I have been doing web-based Javascript (vanilla JS, jQuery, Backbone, etc.) for a few years now, and recently I've been doing some work with Node.js. It took me a while to get the hang of "non-blocking" programming, but I've now gotten used to using callbacks for IO operations and whatnot. I understand that Javascript is single-threaded by nature. I understand the concept of the Node "event queue". What I DON'T understand is what determines whether an individual javascript operation is "blocking" vs. "non-blocking". How do I know which operations I can depend on to produce an output synchronously for me to use in later code, and which ones I'll need to pass callbacks to so I can process the output after the initial operation has completed? Is there a list of Javascript functions somewhere that are asynchronous/non-blocking, and a list of ones that are synchronous/blocking? What is preventing my Javascript app from being one giant race condition? I know that operations that take a long time, like IO operations in Node and AJAX operations on the web, require them to be asynchronous and therefore use callbacks - but who is determining what qualifies as "a long time"? Is there some sort of trigger within these operations that removes them from the normal "event queue"? If not, what makes them different from simple operations like assigning values to variables or looping through arrays, which it seems we can depend on to finish in a synchronous manner? Perhaps I'm not even thinking of this correctly - hoping someone can set me straight. Thanks!

    Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >