Search Results

Search found 466 results on 19 pages for 'polling'.

Page 13/19 | < Previous Page | 9 10 11 12 13 14 15 16 17 18 19  | Next Page >

• Real time web site using PHP or ASP.NET

  - by Roman

  Hey Guys, I'm looking for a way to put real time features into my web site. The idea is asynchronous communication between 2 people - like a chat session. If I use the chat example - I'd like the second person to know that the first one has sent a message to him, without refreshing or doing something active on the web page. Polling is not a good idea here - so is there any other solution? the back-end could be ASP.NET or PHP (ASP.NET preferred). Help would be much appreciated, Thanks, Roman

  Read the article

• cannot read but can write on serial port through Android Emulator

  - by Aad

  I am working on a program that is communicating with serial port over USB through Android emulator. emulator -qemu -serial /dev/ttyUSB0 The emulator is able to open the port and write into it. However, read is not happening. The program has a timeout for read maintained by a timer. The read happens in a separate 'read' thread. The main thread has a socketpair fd pair to signal the read-thread that the serial port is closed post timeout. In the read-thread, polling happens(poll() function call) over the 2 file-descriptors: one is serial port fd, the other is one of the socketpair. The board that I have connected to works fine with sending commands over 'cutecom' The poll never succeeds for serial port. However, poll succeeds for 'socketpair'ed fd and the thread ends on a close-signal sent from main-thread post timeout. Ouestions: Are there any special settings for read as even loop-back fails Are there differences between settings for read and write on a serial port?

  Read the article

• Why a thread is aborted in ASP.NET MVC (again)?

  - by Dario Solera

  Here is what I do in a controller action: create and start a new Thread that does a relatively long processing task (~30 seconds on average, but might be several minutes) immediately return the page response so the user knows processing has started (trivially, a Json with a task ID for polling purposes). At some random point, ThreadAbortException is thrown, so the async task does not complete. The exception is not thrown every time, it just happens randomly roughly 25% of the times. Points to note: I'm not calling Response.End or Response.Redirect - there isn't even a request running when the exception is thrown I tried using ThreadPool and I got the same behavior I know running threads in ASP.NET has several caveats but I don't care right now Any suggestion?

  Read the article

• Ubuntu quickly (python/gtk) - how to monitor stdin?

  - by neil

  I'm starting to work with Ubuntu's "quickly" framework, which is python/gtk based. I want to write a gui wrapper for a textmode C state-machine that uses stdin/stdout. I'm new to gtk. I can see that the python print command will write to the terminal window, so I assume I could redirect that to my C program's stdin. But how can I get my quickly program to monitor stdin (i.e. watch for the C program's stdout responses)? I suppose I need some sort of polling loop, but I don't know if/where that is supported within the "quickly" framework. Or is redirection not the way to go - should I be looking at something like gobject.spawn_async?

  Read the article

• How to receive packets on the MCU's serial port?

  - by itisravi

  Hello, Consider this code running on my microcontroller unit(MCU): while(1){ do_stuff; if(packet_from_PC) send_data_via_gpio(new_packet); //send via general purpose i/o pins else send_data_via_gpio(default_packet); do_other_stuff; } The MCU is also interfaced to a PC via a UART.Whenever the PC sends data to the MCU, the *new_packet* is sent, otherwise the *default_packet* is sent.Each packet can be 5 or more bytes with a pre defined packet structure. My question is: 1.Should i receive the entire packet from PC using inside the UART interrut service routine (ISR)? In this case, i have to implement a state machine inside the ISR to assemble the packet (which can be lengthy with if-else or switch-case blocks). 2.Detect a REQUEST command (one byte)from the PC in my ISR set a flag, diable UART interrupt alone and form the packet in my while(1) loop by polling the UART?

  Read the article

• Is there such a thing as a dektop application event aggregator, similar to that used in Prism?

  - by brownj

  The event aggregator in Prism is great, and allows loosely coupled communication between modules within a composite application. Does such a thing exist that allows the same thing to happen between standalone applications running on a user's desktop? I could imagine developing a solution that uses WCF with TCP binding and running inside Windows Process Activation Service. Client applications could subscribe or publish events to this service as required and it would ensure all other listeners get notified of events as appropriate. Using TCP would enable event messages to be pushed out to clients without the need for polling, ensuring messages are delivered very quickly. I can't help but think though that such a thing would already exist... Is anyone aware of something like this, or have any advice on how it may be best implemented?

  Read the article

• How can I implement "real time" messaging on Google AppEngine?

  - by Freed

  I'm creating a web application on Google AppEngine where I want the user to be notified a quickly as possible after certain events occour. The problem is similar to say a chat server in that I need something happening on one connection (someone is writing a message in a chat room) to propagate to a number of other connections (other people in that chat room gets the message). To get speedy updates from the server to the client I'm planning on using long polling with XmlHttpRequest, hoping that AppEngine won't interfere other than possibly restriing the timeout. The real problem however is efficient notification between connections on AppEngine. Is there any support for this type of cross connection notification on AppEngine that does not involve busy-waiting? The only tools I can think of to do this at all is either using the data storage (slow) or memcache (unreliable), and none of them would let me avoid busy-waiting. Note: I know about XMPP support on AppEngine. It's related, but I want a browser based solution, sending messages to the users by XMPP is not an option.

  Read the article

• Is there an easy way in Python to wait until certain condition is true?

  - by Checkers

  I need to wait in a script until a certain number of conditions become true? I know I can roll my own eventing using condition variables and friends, but I don't want to go through all the trouble of implementing it, since some object property changes come from external thread in a wrapped C++ library (Boost.Python), so I can't just hijack __setattr__ in a class and put a condition variable there, which leaves me with either trying to create and signal a Python condition variable from C++, or wrap a native one and wait on it in Python, both of which sound fiddly, needlessly complicated and boring. Is there an easier way to do it, barring continuous polling of the condition? Ideally it would be along the lines of res = wait_until(lambda: some_predicate, timeout) if (not res): print 'timed out'

  Read the article

• Pushing notifications to a JavaScript?

  - by Michael Stum

  I'm just wondering if there is a way to have a server push information to a JavaScript function. Essentially I have a Dashboard-type page that has a javaScript function to get updates from the server and update the dashboard. I would like my server to be able to "ping" the JS. I don't even know how that could be possible (I'm guessing Twitter and Facebook use polling?), but I'd thought I ask. I heard of Comet, but I don't know if that works with a plain standard IIS 7 installation? (It's a SharePoint 2010 site if that matters in any way) If I understand it correctly, Comet is essentially a constantly open connection, so it seems like it's actually the opposite of what I want (reducing # of requests and therefore load)

  Read the article

• Java reduce CPU usage

  - by steve

  Greets- We gots a few nutters in work who enjoy using while(true) { //Code } in their code. As you can imagine this maxes out the CPU. Does anyone know ways to reduce the CPU utilization so that other people can use the server as well. The code itself is just constantly polling the internet for updates on sites. Therefore I'd imagine a little sleep method would greatly reduce the the CPU usage. Also all manipulation is being done in String objects (Java) anyone know how much StringBuilders would reduce the over head by? Thanks for any pointers

  Read the article

• How would you create a notification system like on SO or Facebook in RoR?

  - by Justin Meltzer

  I'm thinking that notifications would be it's own resource and have a has_many, through relationship with the user model with a join table representing the associations. A user having many notifications is obvious, and then a notification would have many users because there would be a number of standardized notifications (a commenting notification, a following notification etc.) that would be associated with many users. Beyond this setup, I'm unsure how to trigger the creation of notifications based on certain events in your application. I'm also a little unsure of how I'd need to set up routing - would it be it's own separate resource or nested in the user resource? I'd find it very helpful if someone could expand on this. Lastly, ajax polling would likely improve such a feature. There's probably some things I'm missing, so please fill this out so that it is a good general resource.

  Read the article

• Developing a high-performance, scalable Comet application

  - by Rob

  Well, the title says most of it. I'm looking to develop a chat application that will hopefully become something more, and currently I'm considering my options for what I should build it on top of. I've taken a look at Tornado with Redis as my primary option - Tornado, being a Comet server, is perfect for long polling to retrieve the messages on Redis, which I have the intention of using as both a persistent data store, as well as a message queue with its nifty subpub features. However, I've also heard good things about Django, RabbitMQ, MongoDB and Orbited. JavaScript isn't a big problem for me, so Orbited's JavaScript support isn't too much of a boon. Really, I'd probably be happy to develop on the route I've chosen for myself, but if there are any gaping deficiencies in my plan, I'd like some kind person to point them out before I find I've wasted months on this.

  Read the article

• Implementing a server side push for a small number of clients

  - by Helper Method

  For an web application I am working on I have the following requirements: Clients need to be able to log in via a web brower. After logging in, they will be able to change configurations (normal request/response) will be able to receive alarms sent by the server (a server side push) Now, the question is how to implement the alarms. I first thought of using some long polling approach (Comet), but as the amount of clients will definitely belimited to 5-10, I'm now thinking to go with a simpler approach. What are the options I have? Would it be okay to just let the clients poll the server? Important aspects are: Alarms should be delivered in (nearly) real-time. Alarms must not get lost (a lost alarm could cause harm to real people).

  Read the article

• which language to choose for a LIVE web application?

  - by fayer

  i want to create not only a web application, but a web application where everything is LIVE. eg. if someone posts a message and then another one replies, then the creator will get on his webpage a notification. and also i want to implement a chat in the web application. i want these features to be implemented using true server-push (no javascript polling)! because i only want to create web applications i don't think i will use java. i wonder if i should use python, ruby or php for this? thanks

  Read the article

• python mock side_effect or return_value dependent on call_count

  - by user18380

  To test a polling function I want to mock the calling of a sub function so that the first time it is called it will fail, and the second time it is called it will succeed. Here's a very simplified version of it: poll_function(var1): value = sub_function(var1) # First call will return None while not value: time.sleep(POLLING_INTERVAL) value = sub_function(var1) # A subsequent call will return a string, e.g "data" return value Is this possible to do with a Mock object from the mock framework? I know Mock objects have a call_count attribute I should be able to use somehow. Right now I've solved it by creating a custom mock object that I use to monkey patch sub_function(), but I feel there should be a better less verbose way of doing it: def test_poll(): class MyMock(object): def __init__(self, *args): self.call_count = 0 def sub_function(self, *args, **kwargs): if self.call_count > 1: return "data" else: self.call_count += 1 return None my_mock = MyMock() with patch('sub_function', my_mock.sub_function): ok_(poll_function())

  Read the article

• Best way to notify several java applets/applications of a change on a server

  - by Dustin

  I need to know the best (fastest) way to have a server (preferably a php based one, but a jsp/servlet one could be set up as well using google app engine) notify several java applets/applications that a change has occurred to the data. The way i am picturing this to work will be very similar to that of the way i think an online java game (like Runescape) works User 1: Changes data on server. Server: returns success to User 1, notifies connected computers of change. Connected Computer 1: processes change, returns success to server. Connected Computer 2: processes change, returns success to server. Connected Computer 3: processes change, returns success to server. Connected Computer 4: processes change, returns success to server. I am hoping to have this entire process complete in half a second, and not involve polling as there will be long durations of nothing, followed by a sudden moment where 4 events happen in succession.

  Read the article

• Using 50+ 3rd party web services, should I use BizTalk or just C#?

  - by typemismatch

  I'm building a back-end application that needs to fetch data on various schedules from over 50+ 3rd party web services and that number will continue to grow. The data from these services can currently be grouped into 3 types so each response needs to be mapped to 1 of 3 known schemas. Writing custom c# to hit each web service appears to be a management nightmare never mind having all that data mapping in code. The current thinking is build this on top of BizTalk 2009, still a lot of maintenance but at least a well defined platform with mapping/transformation capabilities already. I'm looking for any advise from anyone who might have done this before, does this really buy us anything? I am aware of a lack of polling features in BTS however there are enough work arounds to feel comfortable about the solution. Thanks!

  Read the article

• Messaging in local network with .NET

  - by Richard

  Hi All, I need to implement some form of communication mechanism in my application, to send notifications/messages from one application instance to all the others. This is a normal scenario where someone adds and item or deletes and item and you want to notify other users that this has happened. The application runs on the client and connects to a database on the local network. So its not like all clients access a server instance of the application. So from what I know I could use MessageQueues or some form of Database polling where I have a table that stores all the messages (not ideal). Issue is I need to implement this very quickly, so sadly can't go very complex but need the quickest easiest solution. thanks for the help!

  Read the article

• Loading jQuery multiple times in the same page

  - by Winaji

  I'm implementing a plug-in that's embeddable in different sites (a la Meebo, Wibiya), and I want to use jQuery. Problem is, the site I'm embedding to, may already have a jQuery script loaded. The question is, what's the best approach for this kind of problem: Should I just check if jQuery is already loaded and if so, use the original site's jQuery, otherwise load it myself? If I use this approach, am I not risking comaptibility problems (i.e. the site uses an old version of jQuery)? Should I load jQuery myself (whether it's already loaded or not) and call "jQuery.noConflict(true)" when it's finished loading? If so, how can I make sure that my jQuery has finished loading (hooking to the onLoad event doesn't seem to work all the time, and polling for "jQuery" won't work for obvious reasons)? Should I do something else? Thanks.

  Read the article

• Real time App with Facebook

  - by Casebash

  Does Facebook provide access to any real time APIs so that you can respond to events as soon as they happen? If not, what alternatives are there and what are their limitations? For example, if I use polling instead, will they limit my api calls? And if I try using RSS feeds, about how much delay can I expect? Or maybe it would be possible to receive and process email notifications (if I could convince a user to forward mail to another email address), as they seem to be dispatched pretty promptly?

  Read the article

• Waiting for ServerSocket accept() to put socket into "listen" mode

  - by inazaruk

  I need a simple client-server communication in order to implement unit-test. My steps: Create server thread Wait for server thread to put server socket into listen mode ( serverSocket.accept() ) Create client Make some request, verify responses Basically, I have a problem with step #2. I can't find a way to signal me when server socket is put to "listen" state. An asynchronous call to "accept" will do in this case, but java doesn't support this (it seems to support only asynchronous channels and those are incompatible with "accept()" method according to documentation). Of cause I can put a simple "sleep", but that is not really a solution for production code. So, to summarize, I need to detect when ServerSocket has been put into listen mode without using sleeps and/or polling.

  Read the article

• iphone - Connecting to server in background

  - by Satyam svv

  I'm creating an app which connects to server and sends some text. If network (both wifi or 3g) is there, it will immediately send the text to server. But if there is no network, it keeps on polling for server connection every 5 minutes. All this part is working fine. But when using iPhone 4 device, i want the app to check for server connection even when app goes into background. So, when app goes to background and when network comes back, it must be able to send the text to server. How can I achieve it? I've seen some apps where they say that the app will upload photos to server even in background. How will they do it?

  Read the article

• X11, how to detect I’m the last window/application on the display

  - by ts

  I have an x11 display with a windowmanager (sadly not a specific one, could be twm, dtwm, mwm, metacity …) , myApp and other applications with windows. I want to close the display if the other applications are closed and myApp is the only one with windows on the display. I do know the windows of myApp, but how do I distinguish between the windows of the windowmanger and of the other applications. I’m currently polling with xwininfo -tree -root -children and comparing this to what I’m expecting, but this only works in a ‘well defined’ environment. It seems that many of the above mentioned windowmanager don’t support EWMH.

  Read the article

• java virtual machine - how does it allocate resources?

  - by Will

  I am testing the performance of a data streaming system that supports continuous queries. This is how it works: - There is a polling service which sends data to my system. - As data passes into the system, each query evaluates based on a window of the stream at the current time. - The window slides as data passes in. My problem is this, when I add more queries to the system, I should expect the throughput to decrease because it can't cope the data rate. However, I actually observe an increase in throughput. I can't understand why this is the case and I am guessing that it's something to do with the way the JVM allocates CPU, memory etc. Can anyone shed any light to my problem?

  Read the article

• Internet Protocol Suite: Transition Control Protocol (TCP) vs. User Datagram Protocol (UDP)

  How do we communicate over the Internet?  How is data transferred from one machine to another? These types of act ivies can only be done by using one of two Internet protocols currently. The collection of Internet Protocol consists of the Transition Control Protocol (TCP) and the User Datagram Protocol (UDP).  Both protocols are used to send data between two network end points, however they both have very distinct ways of transporting data from one endpoint to another. If transmission speed and reliability is the primary concern when trying to transfer data between two network endpoints then TCP is the proper choice. When a device attempts to send data to another endpoint using TCP it creates a direct connection between both devices until the transmission has completed. The direct connection between both devices ensures the reliability of the transmission due to the fact that no intermediate devices are needed to transfer the data. Due to the fact that both devices have to continuously poll the connection until transmission has completed increases the resources needed to perform the transmission. An example of this type of direct communication can be seen when a teacher tells a students to do their homework. The teacher is talking directly to the students in order to communicate that the homework needs to be done.  Students can then ask questions about the assignment to ensure that they have received the proper instructions for the assignment. UDP is a less resource intensive approach to sending data between to network endpoints. When a device uses UDP to send data across a network, the data is broken up and repackaged with the destination address. The sending device then releases the data packages to the network, but cannot ensure when or if the receiving device will actually get the data.  The sending device depends on other devices on the network to forward the data packages to the destination devices in order to complete the transmission. As you can tell this type of transmission is less resource intensive because not connection polling is needed,  but should not be used for transmitting data with speed or reliability requirements. This is due to the fact that the sending device can not ensure that the transmission is received.  An example of this type of communication can be seen when a teacher tells a student that they would like to speak with their parents. The teacher is relying on the student to complete the transmission to the parents, and the teacher has no guarantee that the student will actually inform the parents about the request. Both TCP and UPD are invaluable when attempting to send data across a network, but depending on the situation one protocol may be better than the other. Before deciding on which protocol to use an evaluation for transmission speed, reliability, latency, and overhead must be completed in order to define the best protocol for the situation.  

  Read the article

< Previous Page | 9 10 11 12 13 14 15 16 17 18 19  | Next Page >