Search Results

Search found 11135 results on 446 pages for 'thread safe'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 134/446 | < Previous Page | 130 131 132 133 134 135 136 137 138 139 140 141  | Next Page >

  • Parameter passed by const reference returned by const reference.

    - by Alien01
    Hello, I was reading C++ Faq Second Edition , faq number 32.08 . FAQ says that parameter passed by const reference and returned by const reference can cause dangling reference. But it is ok if parameter is passed by reference and returned by reference. I got it that it is unsafe in case of const reference but how is it safe in case when parameter is non const reference. Last line of FAQ says "Note that if a function accepts a parameter by non-const reference (for example, f(string& s)), returning a copy of this reference parameter is safe because a temporary cannot be passed by non-const reference." Need some insight on this!!

    Read the article

  • MacOSX: OSAtomic vs OSAtomicBarrier

    - by anon
    For the functions here: #include <libkern/OSAtomic.h> there are OSAtomic and OSAtomicBarrier versions. However, the documentation does not show sample code for: When is it safe to use just OSAtomic, without the OSAtomicBarrier version When is it that OSAtomic would be unsafe, but OSAtomiBarrier would be safe. Can anyone provide explainations + sample codes? [Random ramblings of "your opinion" without actual code is useless. Readers: please down vote such answers; and vigrously upvote answers with actual code.] [C/C++ code preferred; Assembly okay too.]

    Read the article

  • Why does this script work in the current directory but fail when placed in the path?

    - by kiloseven
    I wish to replace my failing memory with a very small shell script. #!/bin/sh if ! [ –a $1.sav ]; then mv $1 $1.sav cp $1.sav $1 fi nano $1 is intended to save the original version of a script. If the original has been preserved before, it skips the move-and-copy-back (and I use move-and-copy-back to preserve the original timestamp). This works as intended if, after I make it executable with chmod I launch it from within the directory where I am editing, e.g. with ./safe.sh filename However, when I move it into /usr/bin and then I try to run it in a different directory (without the leading ./) it fails with: *-bash: /usr/bin/safe.sh: /bin/sh: bad interpreter: Text file busy* My question is, when I move this script into the path (verified by echo $PATH) why does it then fail? D'oh? Inquiring minds want to know how to make this work.

    Read the article

  • choose append to existing backup instead of overwrite

    - by aron
    Hello, I have a database and I made it's first backup 2 days ago. Then yesterday I spent an entire adding new records. This morning I ran a backup, (but I selected append to existing backup set) as pictured below. I just ran a restore and I found that it wiped out all my data from yesterday and it restored it from the backup of 2 days ago. Not the version from this mornings backup. I zipped this backup file to be safe. I changed some data in the DB, Then I ran the back up again, but this time I selected "overwrite all existing backup sets" Now when I restore the db it's seems to restore the data from the backup correctly. I think I learned a lesson here, correctly if I'm wrong My questions is, Did I lose an entire day of work? I still have this morning's backup .bak file safe in a zip. Is there anyway I can restore is with the right data?

    Read the article

  • Dynamically loading modules in Python (+ threading question)

    - by morpheous
    I am writing a Python package which reads the list of modules (along with ancillary data) from a configuration file. I then want to iterate through each of the dynamically loaded modules and invoke a do_work() function in it which will spawn a new thread, so that the code runs in a separate thread. At the moment, I am importing the list of all known modules at the beginning of my main script - this is a nasty hack I feel, and is not very flexible, as well as being a maintenance pain. This is the function that spawns the threads. I will like to modify it to dynamically load the module when it is encountered. The key in the dictionary is the name of the module containing the code: def do_work(work_info): for (worker, dataset) in work_info.items(): #import the module defined by variable worker here... t = threading.Thread(target=worker.do_work, args=[dataset]) # I'll NOT dameonize since spawned children need to clean up on shutdown # Since the threads will be holding resources #t.daemon = True t.start() Question 1 When I call the function in my script (as written above), I get the following error: AttributeError: 'str' object has no attribute 'do_work' Which makes sense, since the dictionary key is a string (name of the module to be imported). When I add the statement: import worker before spawning the thread, I get the error: ImportError: No module named worker This is strange, since the variable name rather than the value it holds are being used - when I print the variable, I get the value (as I expect) whats going on? Question 2 As I mentioned in the comments section, I realize that the do_work() function written in the spawned children needs to cleanup after itself. My understanding is to write a clean_up function that is called when do_work() has completed successfully, or an unhandled exception is caught - is there anything more I need to do to ensure resources don't leak or leave the OS in an unstable state? Question 3 If I comment out the t.daemon flag statement, will the code stil run ASYNCHRONOUSLY?. The work carried out by the spawned children are pretty intensive, and I don't want to have to be waiting for one child to finish before spawning another child. BTW, I am aware that threading in Python is in reality, a kind of time sharing/slicing - thats ok Lastly is there a better (more Pythonic) way of doing what I'm trying to do?

    Read the article

  • c++ volatile multithreading variables

    - by anon
    I'm writing a C++ app. I have a class variable that more than one thread is writing to. In C++, anything that can be modified without the compiler "realizing" that it's being changed needs to be marked volatile right? So if my code is multi threaded, and one thread may write to a var while another reads from it, do I need to mark the var volaltile? [I don't have a race condition since I'm relying on writes to ints being atomic] Thanks!

    Read the article

  • Java Synchronized function

    - by leon
    Hi I have a question. In the following code, if a thread were blocked at wait statement, and another thread attempts to execute foo(), would the hello wolrd message be printed? and Why? Many Thanks synchronized foo(){ system.out.println("hello world"); ..... wait(); ..... }

    Read the article

  • Managed c++ cross threading

    - by Nitroglycerin
    I got a thread: static void TestThread(System::Object ^obj) { Bot ^ob = (Bot^) obj; while( ob->Threads[0]->IsAlive ){ ob->textBox->text = "test"; // Cross threading error... Thread::Sleep(100); } } Dont know what to do i read about InvokeRequired and Invoke but didnt understand it.. Please help

    Read the article

  • Get ahold of session in command object in Grails

    - by UltraVi01
    How can I get the session from within a command object? I have tried: import org.springframework.security.context.SecurityContextHolder as SCH class MyCommand { def session = RCH.currentRequestAttributes().getSession() } This throws java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.

    Read the article

  • How to reconcile my support of open-source software and need to feed and house myself?

    - by Guzba
    I have a bit of a dilemma and wanted to get some other developers' opinions on it and maybe some guidance. So I have created a 2D game for Android from the ground up, learning and re factoring as I went along. I did it for the experience, and have been proud of the results. I released it for free as ad supported with AdMob not really expecting much out of it, but curious to see what would happen. Its been a few of months now since release, and it has become very popular (250k downloads!). Additionally, the ad revenue is great and is driving me to make more good games and even allowing me to work less so that I can focus on my own works. When I originally began working on the game, I was pretty new to concurrency and completely new to Android (had Java experience though). The standard advice I got for starting an Android game was to look at the sample games from Google (Snake, Lunar Lander, ...) so I did. In my opinion, these Android sample games from Google are decent to see in general what your code should look like, but not actually all that great to follow. This is because some of their features don't work (saving game state), the concurrency is both unexplained and cumbersome (there is no real separation between the game thread and the UI thread since they sync lock each other out all the time and the UI thread runs game thread code). This made it difficult for me as a newbie to concurrency to understand how it was organized and what was really running what code. Here is my dilemma: After spending this past few months slowly improving my code, I feel that it could be very beneficial to developers who are in the same position that I was in when I started. (Since it is not a complex game, but clearly coded in my opinion.) I want to open up the source so that others can learn from it but don't want to lose my ad revenue stream, which, if I did open the source, I fear I would when people released versions with the ad stripped, or minor tweaks that would fragment my audience, etc. I am a CS undergrad major in college and this money is giving me the freedom to work less at summer job, thus giving me the time and will to work on more of my own projects and improving my own skills while still paying the bills. So what do I do? Open the source at personal sacrifice for the greater good, or keep it closed and be a sort of hypocritical supporter of open source?

    Read the article

  • Android Thumbnail Loading Problem

    - by y ramesh rao
    I'm using a thumbnail loader in my project the one mentioned below. The problem is that the it loads all the thumbnails properly except the ones who's size is of about 40K. When our back end is giving that sort of thumbnails are not generated and sometimes this eventually leads to a Crash too. What m I supposed to do with this ? public class ThumbnailManager { private final Map<String, Bitmap> drawableMap; public static Context context; private Resources res; private int thumbnail_size; public ThumbnailManager() { drawableMap = new HashMap<String, Bitmap >(); res = new Resources(context.getAssets(), null, null); thumbnail_size = res.getInteger(R.ThumbnailManager.THUMBNAIL_SIZE); } public Bitmap fetchBitmap(String urlString) { if(drawableMap.containsKey(urlString)) { return (drawableMap.get(urlString)); } //Log.d(getClass().getSimpleName(), " Image URL :: "+ urlString); try { InputStream is = fetch(urlString); android.util.Log.v("ThumbnailManager", "ThumbnailManager " + urlString); drawableMap.put(urlString, BitmapFactory.decodeStream(is));//Bitmap.createScaledBitmap(BitmapFactory.decodeStream(is), thumbnail_size, thumbnail_size, false)); return drawableMap.get(urlString); } catch(Exception e) { android.util.Log.v("EXCEPTION", "EXCEPTION" + urlString); return null; } } public void fetchBitmapOnThread(final String urlString, final ImageView imageView) { if(drawableMap.containsKey(urlString)) { imageView.setImageBitmap(drawableMap.get(urlString)); return; } if(urlString.compareTo("AUDIO") == 0) { Bitmap audioThumb = BitmapFactory.decodeResource(context.getResources(), R.drawable.timeline_audio_thumb); drawableMap.put(urlString, Bitmap.createScaledBitmap(audioThumb, thumbnail_size, thumbnail_size, false)); imageView.setImageBitmap(drawableMap.get(urlString)); return; } final Handler handler = new Handler() { public void handleMessage(Message message) { imageView.setImageBitmap((Bitmap) message.obj); } }; Thread thread = new Thread() { public void run() { Bitmap urlBitmap = fetchBitmap(urlString); Message message = handler.obtainMessage(1, urlBitmap); handler.sendMessage(message); } }; thread.start(); } public InputStream fetch(String urlString) throws IOException, MalformedURLException { final URL url = new URL(urlString); final URLConnection conn = url.openConnection(); HttpURLConnection httpConn = (HttpURLConnection) conn; httpConn.setAllowUserInteraction(true); httpConn.setInstanceFollowRedirects(true); httpConn.setRequestMethod("GET"); httpConn.connect(); return(conn.getInputStream()); } }

    Read the article

  • Java: Multithreading & UDP Socket Programming

    - by Ravi
    I am new to multithreading & socket programming in Java. I would like to know what is the best way to implement 2 threads - one for receiving a socket and one for sending a socket. If what I am trying to do sounds absurd, pls let me know why! The code is largely inspired from Sun's tutorials online.I want to use Multicast sockets so that I can work with a multicast group. class server extends Thread { static protected MulticastSocket socket = null; protected BufferedReader in = null; public InetAddress group; private static class receive implements Runnable { public void run() { try { byte[] buf = new byte[256]; DatagramPacket pkt = new DatagramPacket(buf,buf.length); socket.receive(pkt); String received = new String(pkt.getData(),0,pkt.getLength()); System.out.println("From server@" + received); Thread.sleep(1000); } catch (IOException e) { System.out.println("Error:"+e); } catch (InterruptedException e) { System.out.println("Error:"+e); } } } public server() throws IOException { super("server"); socket = new MulticastSocket(4446); group = InetAddress.getByName("239.231.12.3"); socket.joinGroup(group); } public void run() { while(1>0) { try { byte[] buf = new byte[256]; DatagramPacket pkt = new DatagramPacket(buf,buf.length); //String msg = reader.readLine(); String pid = ManagementFactory.getRuntimeMXBean().getName(); buf = pid.getBytes(); pkt = new DatagramPacket(buf,buf.length,group,4446); socket.send(pkt); Thread t = new Thread(new receive()); t.start(); while(t.isAlive()) { t.join(1000); } sleep(1); } catch (IOException e) { System.out.println("Error:"+e); } catch (InterruptedException e) { System.out.println("Error:"+e); } } //socket.close(); } public static void main(String[] args) throws IOException { new server().start(); //System.out.println("Hello"); } }

    Read the article

  • Getting huge lags when downloading files via Service

    - by Copa
    I have a Service which receives URLs to download. The Service than downloads these URLs and save them to a file on the SD Card. When I put more than 2 items in the download queue my device is unusable. It nearly freezes. Huge lags and so on. Any idea? Sourcecode: private static boolean downloading = false; private static ArrayList<DownloadItem> downloads = new ArrayList<DownloadItem>(); /** * called once when the service started */ public static void start() { Thread thread = new Thread(new Runnable() { @Override public void run() { while (true) { if (downloads.size() > 0 && !downloading) { downloading = true; DownloadItem item = downloads.get(0); downloadSingleFile(item.getUrl(), item.getFile()); } } } }); thread.start(); } public static void addDownload(DownloadItem item) { downloads.add(item); } private static void downloadSuccessfullFinished() { if (downloads.size() > 0) downloads.get(0).setDownloaded(true); downloadFinished(); } private static void downloadFinished() { // remove the first entry; it has been downloaded if (downloads.size() > 0) downloads.remove(0); downloading = false; } private static void downloadSingleFile(String url, File output) { final int maxBufferSize = 4096; HttpResponse response = null; try { response = new DefaultHttpClient().execute(new HttpGet(url)); if (response != null && response.getStatusLine().getStatusCode() == 200) { // request is ok InputStream is = response.getEntity().getContent(); BufferedInputStream bis = new BufferedInputStream(is); RandomAccessFile raf = new RandomAccessFile(output, "rw"); ByteArrayBuffer baf = new ByteArrayBuffer(maxBufferSize); long current = 0; long i = 0; // read and write 4096 bytes each time while ((current = bis.read()) != -1) { baf.append((byte) current); if (++i == maxBufferSize) { raf.write(baf.toByteArray()); baf = new ByteArrayBuffer(maxBufferSize); i = 0; } } if (i > 0) // write the last bytes to the file raf.write(baf.toByteArray()); baf.clear(); raf.close(); bis.close(); is.close(); // download finished get start next download downloadSuccessfullFinished(); return; } } catch (Exception e) { // not successfully downloaded downloadFinished(); return; } // not successfully downloaded downloadFinished(); return; }

    Read the article

  • some fields of "content//sms/"

    - by soclose
    Hi, I query "content//sms/" and don't know what some fields are. They are - Thread ID Protocol Status Reply_Path_Present Service_Center I check them in LogCat. I find them like below Thread ID : 1 to 6 etc.. Protocol : null / 0 Status : -1 Reply_Path_Present : null / 0 Service_Center : null Please tell me what they are.

    Read the article

  • C99 strict aliasing rules in C++ (GCC)

    - by Checkers
    As far as I understand, GCC supports all of its C99 features in C++. But how is C99 strict aliasing handled in C++ code? I know that casting with C casts between unrelated types is not strict-aliasing-safe and may generate incorrect code, but what about C++? Since strict aliasing is not part of C++ standard (is that correct?), GCC must be specifying the semantics itself. I figure const_cast and static_cast cast between related types, hence they are safe, while reinterpret_cast can break strict aliasing rules. Is this a correct understanding?

    Read the article

  • Unload event for the default AppDomain?

    - by Zor
    Hi, I need to have an event fired whenever any AppDomain unloads - including the default one of the process. The problem with AppDomain.DomainUnload is that it only fires for non-default AppDomains. Furthermore, AppDomain.ProcessExit has limited execution time, which I cannot rely on. Any suggestions as to how I can achieve this would be greatly appreciated! (Alternatively, having an event fired when a background thread (Thread.IsBackground == True) works too.) Thanks in advance.

    Read the article

  • nonatomic property in model class when using NSOperationQueue (iPhone)?

    - by Andrew B.
    I have a custom model class with an NSMutableData ivar that will be accessed by custom NSOperation subclasses (using an NSOperationQueue). I think I can guarantee thread-safe access to the ivar from multiple NSOperations by using dependencies, and I can guarantee that I don't access the ivar from other code (say my main app thread) by waiting until the Q has finished all operations. Should I use a nonatomic property specification, or leave it atomic? Is there a significant impact on performance?

    Read the article

  • Where to begin with multi-threaded programming with c++?

    - by zoke
    I'm trying to implement my own IRC client as a personal proejct and I realized I needed a way to read and write from the socket at the same time. I realized I could have a reading thread which reads from the socket in the background and puts data in a queue and I could have another thread which writes data from a queue to the socket. However I have no idea on how to start with multithreaded programing or how to do it with c++. Where do I go from here?

    Read the article

  • Converting Mod-rewrite rules which use %(QUERY_STRING) to NGINX rewrite format?

    - by HipHop-opatamus
    I've been stuck the last few days trying to convert the following Apache/Mod_Rewrite rewrite rule to NGINX format. Anyone know where I am going wrong? MOD_REWRITE: RewriteCond %{QUERY_STRING} topic=([0-9]+) RewriteRule /forum/index\.php /forum/vbseo301.php?action=thread&oldid=%1 [L] NGINX: location /forum/index.php { if ($args ~ "topic=([0-9]+)"){ rewrite ^/forum/index\.php?topic=(.+)$ /forum/vbseo301.php?action=thread&oldid=$1 last; } }

    Read the article

  • openmp sections running sequentially

    - by chi42
    I have the following code: #pragma omp parallel sections private(x,y,cpsrcptr) firstprivate(srcptr) lastprivate(srcptr) { #pragma omp section { //stuff } #pragma omp section { //stuff } } According to the Zoom profiler, two threads are created, one thread executes both the sections, and the other thread simply blocks! Has anyone encountered anything like this before? (And yes, I do have a dual core machine).

    Read the article

  • BSoD when creating threads

    - by Behrooz
    I am trying to create +5 threads synchronously so there shouldn't be any concurrency error. Code: System.Threading.Thread t = new System.Threading.Thread(proc); t.Start();//==t.BlueScreen(); t.Join(); Is darkness a feature ? I am doing something wrong? OS:Microsoft windows vista(unfortunately) x64 Language:C# 3.0|4.0 .Net version:3.5|4

    Read the article

  • Tools for Debugging ThreadPool Issues in Visual Studio 2010.

    - by ProfK
    I have never spent much time debugging multithreaded .NET apps (or others), and have quite a simple one to solve very quickly. Ideally I would imagined and would lurve to be able to intercept thread creation and use by worker objects, so that nothing unexpected happens while I'm on a breakpoint in my thread. Is that realistic? What else is there in VS 2010?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 130 131 132 133 134 135 136 137 138 139 140 141  | Next Page >