Search Results

Search found 413 results on 17 pages for 'spawn'.

Page 11/17 | < Previous Page | 7 8 9 10 11 12 13 14 15 16 17  | Next Page >

  • How to kill all subprocesses of shell?

    - by depesz
    I'm writing bash script, which does several thing. In the beginning it starts several monitor scripts, each of them runs some other tools. At the end of my main script, I would like to kill all things that spawned from my shell. So, it might looks like this: #!/bin/bash some_monitor1.sh & some_monitor2.sh & some_monitor3.sh & do_some_work ... kill_subprocesses The thing is that most of these monitors spawn their own subprocesses, so doing (for example): killall some_monitor1.sh will not always help. Any other way to handle this situation?

    Read the article

  • What is the "task" in twitter Storm parallelism

    - by John Wang
    I'm trying to learn twitter storm by following the great article "Understanding the parallelism of a Storm topology" However I'm a bit confused by the concept of "task". Is a task an running instance of the component(spout or bolt) ? A executor having multiple tasks actually is saying the same component is executed for multiple times by the executor, am I correct ? Moreover in a general parallelism sense, Storm will spawn a dedicated thread(executor) for a spout or bolt, but what is contributed to the parallelism by an executor(thread) having multiple tasks ? I think having multiple tasks in a thread, since a thread executes sequentially, only make the thread a kind of "cached" resource, which avoids spawning new thread for next task run. Am I correct? I may clear those confusion by myself after taking more time to investigate, but you know, we both love stackoverflow ;-) Thanks in advance.

    Read the article

  • Including the functionality of a tool within another program?

    - by darren
    Hi there I would like to write an application, for my own interest, that graphically visualizes some network concepts. Basically I would like to show the output from tools like ping, traceroute and nmap. The most obvious approach seems to be to use pipes to call out to these tools from my C program, and process the information they return. However, I would like to avoid this heavy-handed approach if possible. My question is, is it possible to somehow link against these tools, or are there APIs that can be used to gain programatic access instead? If so, is this behavior available on a tool-by-tool basis only? One reason for wanting to do this is to keep everything in a single process / address space and to avoid dependance on these external tools. For example, if I wrote an iphone application, I would not be able to spawn processes to call out to the external tools themselves. Thanks for any advice or suggestions.

    Read the article

  • Erlang message loops

    - by Roger Alsing
    How does message loops in erlang work, are they sync when it comes to processing messages? As far as I understand, the loop will start by "receive"ing a message and then perform something and hit another iteration of the loop. So that has to be sync? right? If multiple clients send messages to the same message loop, then all those messages are queued and performed one after another, or? To process multiple messages in parallell, you would have to spawn multiple message loops in different processes, right? Or did I misunderstand all of it?

    Read the article

  • Downloading HTTP URLs asynchronously in C++

    - by Joey Adams
    What's a good way to download HTTP URLs (e.g. such as http://0.0.0.0/foo.htm ) in C++ on Linux ? I strongly prefer something asynchronous. My program will have an event loop that repeatedly initiates multiple (very small) downloads and acts on them when they finish (either by polling or being notified somehow). I would rather not have to spawn multiple threads/processes to accomplish this. That shouldn't be necessary. Should I look into libraries like libcurl? I suppose I could implement it manually with non-blocking TCP sockets and select() calls, but that would likely be less convenient.

    Read the article

  • handling activity destruction in multithreaded android app

    - by Jayesh
    Hi, I have a multithreded app where background threads are used to load data over network or from disk/db. Every once in a while user will perform some action e.g. fetch news over network, which will spawn a background AsyncTask, but for some reason user will quit the app (press back button so that activity gets destroyed). In most such scenarios, I make appropriate checks in the background thread after it returns from n/w i/o, so that it won't crash by accessing members of the activity that is destroyed by now. However some corner cases are left where crashes happen, because the background thread would access some member of activity that is now null. Do other Android developers have some generic/recommended framework to handle such scenarios? These are the times when I wish android would have guaranteed termination of all threads when activity destroys (in the same way that regular linux process cleans up when it's quit)... but I guess Android devs had good reasons for not exposing process lifetimes through the api.

    Read the article

  • how to selfhost wcf without iis

    - by dotnetcoder
    Reading up on WCF we have self hosting option available , one limitation here is we have to manage the host process lifecycle ourselves. What I am exploring here is to run the service without IIS and do a self hosting. Few things come to mind - How will request management work here. In case of IIS it manages the request and give control to dotnet on a particular thread. In absence of IIS do we need to write code ourselves to manage incoming requests ( say on a tcp port ) or WCF provides some classes to manage request and spawn threads to process each thread. I am aware that in case of self hosting this needs to be a windows service. In case of self hosting how can me tap on the number of simultaneous requests on the sever , it can be managed by limiting the thread pool ? or we can configure this via wcf ? Thanks dc

    Read the article

  • ncurses - expect: sleep executes at wrong time

    - by rahul
    I have some ncurses apps that I need to automate to test repeatedly. I am placing the "sleep" command between "send" commands. However, what i see is that all the sleep's are executed in the beginning before the screen loads. expect concatenates the sends (I see that at the screen bottom during sleep) then issues them together. I have tried sending all keys with "send -s" or "send -h". That marginally helps. I've replaced "-f" on line 1 with "-b" - again a tiny difference. Why isn't "sleep" pausing at the right time. Incidentally, my programs have a getc() loop, so i can't use "expect" command. I tried that too. #!/usr/bin/expect -f spawn ruby testsplit.rb #expect set send_human {3 3 5 5 7} set send_slow {10 1} exp_send -s -- "--" exec sleep 3 send -s "+" send -s "=" sleep 1 send -h -- "-" send -h -- "-" sleep 1 send -h -- "v" interact

    Read the article

  • What to do when ServerSocket throws IOException

    - by s5804
    Basically I want to create a rock solid server. while (keepRunning.get()) { try { Socket clientSocket = serverSocket.accept(); ... spawn a new thread to handle the client ... } catch (IOException e) { e.printStackTrace(); // NOW WHAT? } } In the IOException block, what to do? Is the Server socket at fault so it need to be recreated? For example wait a few seconds and then serverSocket = ServerSocketFactory.getDefault().createServerSocket(MY_PORT); However if the server socket is still OK, then it is a pity to close it and kill all previously accepted connections that are still communicating.

    Read the article

  • iphone app photo upload to server from app threads

    - by user290380
    I have an app that needs to upload a least 5 photos to a server using API call available with the server. For that I am planning to use threads which will take care of photo upload and the main process can go on with the navigation of views etc. What I cant decide is whether it is OK to spawn five separate threads in iphone or use a single thread that will do the upload. In the later cases obviously it will become quite slow. Basically an HTTP POST request will be made to the server with the NSMutableURLRequest object using NSCOnnection. More threads mean more complexity and sync issues, but I can try to write code as neat as possible if it means better performance than a single thread which is simple but is a real stopper if performance is considered. Anybody with any experience in this kinda app. ??

    Read the article

  • How can I prevent ADO from creating multiple SPIDs?

    - by stusmith
    I'm working on an application that creates a single ADO connection and keeps it open for the lifetime of the application. I have connection pooling turned off. (Please ignore the fact that this might not be best practice for the purposes of this question). If I spawn a new thread and use the exact same ADO connection, it uses a new SPID behind the scenes. Is there anyway to ensure an ADO connection always uses the same SPID, across all threads? (For reference the application is VC++ using ADO via COM to SQL Server).

    Read the article

  • Running Services.msc as a different User C#

    - by Simon Mark Smith
    Hi, I have a requirement to create a simple windows forms application that allows an admin user to manage the Services on remote servers. We don't want to give the admins the usernames and passwords to the servers so these will be encrypted and stored in a database. My question is whether or not it is possible to spawn a Services.msc window when impersonating one of the users stored within the database? I have looked at the ProcessStartInfo class but because Services.msc is not an executable it does not seem to like executing this. Any ideas on a simple way of doing the actual impersonation and loading of Services.msc - say off a button click? Thanks

    Read the article

  • Begin Viewing Query Results Before Query Ends

    - by Frank Developer
    OK, so say I have a table with 500K rows, then I ad-hoc query with unsupported indexing which requires a full table scan. I would like to immediately view the first rows returned while the full table scan continues. Then I want to scroll thru the next results. In the meantime, I would like to display the progress of the table scan, example: "SEARCHING.. FOUND 23 OF 500,000 ROWS SO FAR". If I scroll too far ahead, I want to display a message like: "REACHED LAST ROW IN LOOK-AHEAD BUFFER.. QUERY HAS NOT COMPLETED".. Can this be done? Maybe like: spawn/exec, declare scroll cursor, open, fetch, etc.?

    Read the article

  • Looking for suggestions about an architecture of a MultiThreaded app.

    - by Dimitri
    Hello everyone. I am looking to develop a multithreaded application that will be running in unconditional loop and processing high volume of data. High volume is 2000+ records per minute. Processing will involve data retrieval, calculations and data updates. I need the application to perform so that there is virtually no back log, meaning i need to be able to finish up all of the 2000 points in one minute or even faster. Our current implementation features a multithreaded application that is spawn multiple times (from 10 to 20) and we are noticing that it's not handling data as expected and i even feel that instances of the application compete with each other for processor time and eventually if not slowing, not benefiting each other for sure. I would like to know what would be the best approach: have a single instance running but maximize threads that can run simultaneously? or is there other ways i don't know? I'm open to suggestions. Thank you in advance

    Read the article

  • How to avoid StaleObjectStateException when transaction updates thousands of entities?

    - by ThinkFloyd
    We are using Hibernate 3.6.0.Final with JPA 2 and Spring 3.0.5 for a large scale enterprise application running on tomcat 7 and MySQL 5.5. Most of the transactions in application, lives for less than a second and update 5-10 entities but in some use cases we need to update more than 10-20K entities in single transaction, which takes few minutes and hence more than 70% of times such transaction fails with StaleObjectStateException because some of those entities got updated by some other transaction. We generally maintain version column in all tables and in case of StaleObjectStateException we generally retry but since these longs transactions are anyways very long so if we keep on retrying then also I am not very sure that we'll be able to escape StaleObjectStateException. Also lot of activities keep updating these entities in busy hours so we cannot go with pessimistic approach because it can potentially halt many activities in system. Please suggest how to fix such long transaction issue because we cannot spawn thousands of independent and small transactions because we cannot afford messed up data in case of some failed & some successful transactions.

    Read the article

  • What to use to wait on a indeterminate number of tasks?

    - by Scott Chamberlain
    I am still fairly new to parallel computing so I am not too sure which tool to use for the job. I have a System.Threading.Tasks.Task that needs to wait for n number number of tasks to finish before starting. The tricky part is some of its dependencies may start after this task starts (You are guaranteed to never hit 0 dependent tasks until they are all done). Here is kind of what is happening Parent thread creates somewhere between 1 and (NUMBER_OF_CPU_CORES - 1) tasks. Parent thread creates task to be run when all of the worker tasks are finished. Parent thread creates a monitoring thread Monitoring thread may kill a worker task or spawn a new task depending on load. I can figure out everything up to step 4. How do I get the task from step 2 to wait to run until any new worker threads created in step 4 finish?

    Read the article

  • Parent Thread exiting before Child Threads [python]

    - by crgwbr
    I'm using Python in a webapp (CGI for testing, FastCGI for production) that needs to send an occasional email (when a user registers or something else important happens). Since communicating with an SMTP server takes a long time, I'd like to spawn a thread for the mail function so that the rest of the app can finish up the request without waiting for the email to finish sending. I tried using thread.start_new(func, (args)), but the Parent return's and exits before the sending is complete, thereby killing the sending process before it does anything useful. Is there anyway to keep the process alive long enough for the child process to finish?

    Read the article

  • Accurate clock in Erlang

    - by buddhabrot
    I was thinking about how to implement a process that gives the number of discrete intervals in time that occurred since it started. Am I losing accuracy here? How do I implement this without loss of accuracy after a while and after heavy client abuse. I am kind of stumped how to do this in Erlang. -module(clock). -compile([export_all]). start(Time) -> register(clock, spawn(fun() -> tick(Time, 0) end)). stop() -> clock ! stop. tick(Time, Count) -> receive nticks -> io:format("~p ticks have passed since start~n", [Count]) after 0 -> true end, receive stop -> void after Time -> tick(Time, Count + 1) end.

    Read the article

  • LINQ Changeset multi-threading

    - by Xodarap
    I'm using LINQ to SQL and after I submit some changes I want to spawn a thread which looks through all the changes and updates our lucene index as necessary. My code looks vaguely like: (new Thread(() => { UpdateIndex(context.GetChangeSet()); }).Start(); Sometimes though I get an InvalidOperationException, which I think is because context.GetChangeSet() is not thread-safe, and so if the change set is modified in one thread while another thread is enumerating through it, problems arise. Is there a "thread-safe" version of GetChangeSet()? Or some way I can do ChangeSet.clone() or something?

    Read the article

  • Killing a subprocess including its children from python

    - by user316664
    Hi, I'm using the subprocess module on python 2.5 to spawn a java program (the selenium server, to be precise) as follows: import os import subprocess display = 0 log_file_path = "/tmp/selenium_log.txt" selenium_port = 4455 selenium_folder_path = "/wherever/selenium/lies" env = os.environ env["DISPLAY"] = ":%d.0" % display command = ["java", "-server", "-jar", 'selenium-server.jar', "-port %d" % selenium_port] log = open(log_file_path, 'a') comm = ' '.join(command) selenium_server_process = subprocess.Popen(comm, cwd=selenium_folder_path, stdout=log, stderr=log, env=env, shell=True) This process is supposed to get killed once the automated tests are finished. I'm using os.kill to do this: os.killpg(selenium_server_process.pid, signal.SIGTERM) selenium_server_process.wait() This does not work. The reason is that the shell subprocess spawns another processfor the java program, and the pid of that process is unknown to my python code. I've tried killing the process group with os.killpg, but that kills also the python process which runs this code in the first place. Setting shell to false, thus avoiding the java program to run inside a shell environment, is also out of the question, due to other reasons. Does anyone have an idea how I can kill the shell and any other processes generated by it? Cheers, Ulas

    Read the article

  • Oracle checking existence before deletion in a trigger

    I have analyzed a hibernate generated oracle database and discovered that a delete of a row from a single table will spawn the firing of 1200+ triggers in order to delete the related rows in child tables. The triggers are all auto-generated the same - an automatic delete of a child row without checking for existence first. As it is impossible to predict which child tables will actually have related rows, I think a viable solution to preventing the firing of the cascaded delete down a deeply branched completely empty limb, would be to check for the existence of a related row before attempting to delete. In other dbms', I could simply state " if exists....." before deleting. Is there a comparable way to do this in oracle?

    Read the article

  • A few things I learned regarding Azure billing policies

    - by Vincent Grondin
    An hour of small computing time: 0,12$ per hour A Gig of storage in the cloud: 0,15$ per hour 1 Gig of relational database using Azure SQL: 9,99$  per month A Visual Studio Professional with MSDN Premium account: 2500$ per year Winning an MSDN Professional account that comes preloaded with 750 free hours of Azure per month:  PRICELESS !!!      But was it really free???? Hmmm… Let’s see.....   Here's a few things I learned regarding Azure billing policies when I attended a promotional training at Microsoft last week...   1)  An instance deployed in the cloud really means whatever you upload in there... it doesn't matter if it's in STAGING OR PRODUCTION!!!!   Your MSDN account comes with 750 free hours of small computing time per month which should be enough hours per month for one instance of one application deployed in the cloud...  So we're cool, the application you run in the cloud doesn't cost you a penny....  BUT the one that's in staging is still consuming time!!!   So if you don’t want to end up having to pay 42$ at the end of the month on your credit card like this happened to a friend of mine, DELETE them staging applications once you’ve put them in production! This also applies to the instance count you can modify in the configuration file… So stop and think before you decide you want to spawn 50 of those hello world apps  .     2) If you have an MSDN account, then you have the promotional 750 hours of Azure credits per month and can use the Azure credits to explore the Cloud! But be aware, this promotion ends in 8 months (maybe more like 7 now) and then you will most likely go back to the standard 250 hours of Azure credits. If you do not delete your applications by then, you’ll get billed for the extra hours, believe me…   There is a switch that you can toggle and which will STOP your automatic enrollment after the promotion and prevent you from renewing the Azure Account automatically. Yes the default setting is to automatically renew your account and remember, you entered your credit card information in the registration process so, yes, you WILL be billed…  Go disable that ASAP    Log into your account, go to “Windows Azure Platform” then click the “Subscriptions” tab and on the right side, you’ll see a drop down with different “Actions” into it… Choose “Opt out of auto renew” and, NOW you’re safe…   Still, this is a great offer by Microsoft and I think everyone that has a chance should play a bit with Azure to get to know this technology a bit more...     Happy Cloud Computing All

    Read the article

  • Vote of Disconfidence to Entity Framework

    - by Ricardo Peres
    A friend of mine has found the following problem with Entity Framework 4: Two simple classes and one association between them (one to many): One condition to filter out soft-deleted entities (WHERE Deleted = 0): 100 records in the database; A simple query: 1: var l = ctx.Person.Include("Address").Where(x => (x.Address.Name == "317 Oak Blvd." && x.Address.Number == 926) || (x.Address.Name == "891 White Milton Drive" && x.Address.Number == 497)); Will produce the following SQL: 1: SELECT 2: [Extent1].[Id] AS [Id], 3: [Extent1].[FullName] AS [FullName], 4: [Extent1].[AddressId] AS [AddressId], 5: [Extent202].[Id] AS [Id1], 6: [Extent202].[Name] AS [Name], 7: [Extent202].[Number] AS [Number] 8: FROM [dbo].[Person] AS [Extent1] 9: LEFT OUTER JOIN [dbo].[Address] AS [Extent2] ON ([Extent2].[Deleted] = 0) AND ([Extent1].[AddressId] = [Extent2].[Id]) 10: LEFT OUTER JOIN [dbo].[Address] AS [Extent3] ON ([Extent3].[Deleted] = 0) AND ([Extent1].[AddressId] = [Extent3].[Id]) 11: LEFT OUTER JOIN [dbo].[Address] AS [Extent4] ON ([Extent4].[Deleted] = 0) AND ([Extent1].[AddressId] = [Extent4].[Id]) 12: LEFT OUTER JOIN [dbo].[Address] AS [Extent5] ON ([Extent5].[Deleted] = 0) AND ([Extent1].[AddressId] = [Extent5].[Id]) 13: LEFT OUTER JOIN [dbo].[Address] AS [Extent6] ON ([Extent6].[Deleted] = 0) AND ([Extent1].[AddressId] = [Extent6].[Id]) 14: ... 15: WHERE ((N'317 Oak Blvd.' = [Extent2].[Name]) AND (926 = [Extent3].[Number])) 16: ... And will result in 680 MB of memory being taken! Now, Entity Framework has been historically known for producing less than optimal SQL, but 680 MB for 100 entities?! According to Microsoft, the problem will be addressed in the following version, there is a Connect issue open. There is even a whitepaper, Performance Considerations for Entity Framework 5, which talks about some of the changes and optimizations coming on version 5, but by reading it, I got even more concerned: “Once the cache contains a set number of entries (800), we start a timer that periodically (once-per-minute) sweeps the cache.” Say what?! The next version of Entity Framework will spawn timer threads?! When Code First came along, I thought it was a step in the right direction. Sure, it didn’t include some things that NHibernate did for quite some time – for example, different strategies for Id generation that do not rely on IDENTITY columns, which makes INSERT batching impossible, or support for enumerated types – but I thought these would come with the time. Now, enumerated types have, but so did… timer threads! I’m afraid Entity Framework is becoming a monster.

    Read the article

  • Android, how important is deltaTime?

    - by iQue
    Im making a game that is getting pretty big and sometimes my thread has to skip a frame, so far I'm not using deltaTime for setting the speed of my different objects in the game because it's still not a big enough game for it to matter imo. But its getting bigger then I planned, so my question is, how important is delta Time? If I should use delta time there is a problem, since speedX and speedY are integers(they have to be for eclipse to let you make a rectangle of them), I cant add delta time very functionally as far as I understand, but might be wrong? Ive tried adding deltaTime to the code below, and sometimes my enemies just not move after spawn, they just stand there and run in the same place Will add an some code for how I set / use speed: public void update(int dx, int dy) { double theta = 180.0 / Math.PI * Math.atan2(-(y - controls.pointerPosition.y), controls.pointerPosition.x - x); x +=dx * Math.cos(Math.toRadians(theta)); y +=dy * Math.sin(Math.toRadians(theta)); currentFrame = ++currentFrame % BMP_COLUMNS; } public void draw(Canvas canvas) { int srcX = currentFrame * width; int srcY = 1 * height; Rect src = new Rect(srcX, srcY, srcX + width, srcY + height); Rect dst = new Rect(x, y, x + width, y + height); canvas.drawBitmap(bitmap, src, dst, null); } So if someone with some experience with this has any thoughts, please share. Thank you! Changed code: public void update(int dx, int dy, float delta) { double theta = 180.0 / Math.PI * Math.atan2(-(y - controls.pointerPosition.y), controls.pointerPosition.x - x); double speedX = delta * dx * Math.cos(Math.toRadians(theta)); double speedY = delta * dy * Math.sin(Math.toRadians(theta)); x += speedX; y += speedY; currentFrame = ++currentFrame % BMP_COLUMNS; } public void draw(Canvas canvas) { int srcX = currentFrame * width; int srcY = 1 * height; Rect src = new Rect(srcX, srcY, srcX + width, srcY + height); Rect dst = new Rect(x, y, x + width, y + height); canvas.drawBitmap(bitmap, src, dst, null); } with this code my enemies move like before, except they wont move to the right (wont increment x), all other directions work.

    Read the article

  • June 23, 1983: First Successful Test of the Domain Name System [Geek History]

    - by Jason Fitzpatrick
    Nearly 30 years ago the first Domain Name System (DNS) was tested and it changed the way we interacted with the internet. Nearly impossible to remember number addresses became easy to remember names. Without DNS you’d be browsing a web where numbered addresses pointed to numbered addresses. Google, for example, would look like http://209.85.148.105/ in your browser window. That’s assuming, of course, that a numbers-based web every gained enough traction to be popular enough to spawn a search giant like Google. How did this shift occur and what did we have before DNS? From Wikipedia: The practice of using a name as a simpler, more memorable abstraction of a host’s numerical address on a network dates back to the ARPANET era. Before the DNS was invented in 1983, each computer on the network retrieved a file called HOSTS.TXT from a computer at SRI. The HOSTS.TXT file mapped names to numerical addresses. A hosts file still exists on most modern operating systems by default and generally contains a mapping of the IP address 127.0.0.1 to “localhost”. Many operating systems use name resolution logic that allows the administrator to configure selection priorities for available name resolution methods. The rapid growth of the network made a centrally maintained, hand-crafted HOSTS.TXT file unsustainable; it became necessary to implement a more scalable system capable of automatically disseminating the requisite information. At the request of Jon Postel, Paul Mockapetris invented the Domain Name System in 1983 and wrote the first implementation. The original specifications were published by the Internet Engineering Task Force in RFC 882 and RFC 883, which were superseded in November 1987 by RFC 1034 and RFC 1035.Several additional Request for Comments have proposed various extensions to the core DNS protocols. Over the years it has been refined but the core of the system is essentially the same. When you type “google.com” into your web browser a DNS server is used to resolve that host name to the IP address of 209.85.148.105–making the web human-friendly in the process. Domain Name System History [Wikipedia via Wired] What is a Histogram, and How Can I Use it to Improve My Photos?How To Easily Access Your Home Network From Anywhere With DDNSHow To Recover After Your Email Password Is Compromised

    Read the article

< Previous Page | 7 8 9 10 11 12 13 14 15 16 17  | Next Page >