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• Performance implications of finalizers on JVM

  - by Alexey Romanov

  According to this post, in .Net, Finalizers are actually even worse than that. Besides that they run late (which is indeed a serious problem for many kinds of resources), they are also less powerful because they can only perform a subset of the operations allowed in a destructor (e.g., a finalizer cannot reliably use other objects, whereas a destructor can), and even when writing in that subset finalizers are extremely difficult to write correctly. And collecting finalizable objects is expensive: Each finalizable object, and the potentially huge graph of objects reachable from it, is promoted to the next GC generation, which makes it more expensive to collect by some large multiple. Does this also apply to JVMs in general and to HotSpot in particular?

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• IE7 is messing up the z-index property with my subnav (although I've already fixed that!)

  - by JAG2007

  OK, so I had this issue with my jQuery subnav in IE7 where it was scrolling down behind the main content after the header. Did a fair bit of research and found a great fix involving simply applying a z-index value to the header, and one to the main content. All was well. Or so I thought. Turns out IE7 is still messing up the subnav z-index within the header itself. The subnav still drops down behind the tagline, which is also part of the header. Particularly when you hit the subnav on the "Help Now" tab. (again, IE7 only) http://betawww.helpcurenow.org I've applied z-index values to both the subnav and the tagline, but that did not resolve the issue as did adding z-index values for the header and maincontent divs. Any tips? Did I specify my z-index improperly with the subnav? (should I have applied to the parent element?)

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• problem in multiple asynchronous calls on webservice method in wpf application

  - by black sensei

  Hello Experts! i'm trying to create an application which connects to internet and consume web services for every of it's operation.As far as i'm concerned i'll like to useasync method which i'm using already to get a collection of Contacts.I've realized that when i'm doing the same for groups (meaning getting groups async) i'm having errors in the calls , but when using normal call there ins't.So i did some research online and find that a lot of people has the same problem. Some of them are asked to use WCF (for which i don't know jack).I'll like to know if there is another way to overcome this. if not can somebody point me to reliable resource online and help me get through it? thanks for reading and helping

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• Correct (pretty) window redraw during the creation

  - by Coder

  Does anyone know what is a correct way to redraw window during lengthy initialization operations? Say I have HWND with NULL brush, and it does some not so quick child window initialization (Window initialization is not so quick on Vista and 7, especially on netbooks, even with threaded app). With this config window stays black for half a second on slower laptops. But if I supply window color brush, it seems that there are some sort of child controls or something that draws black squares on top of it, which also seems ugly. Even though the controls are created without WS_VISIBLE initially. Oh, the window has the WS_EX_COMPOSITED style, which should do the double buffering to avoid flicker. But it still behaves ugly. Are there any other tricks I've forgotten, missed?

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• When to use Vanilla Javascript vs. jQuery?

  - by jondavidjohn

  I have noticed while monitoring/attempting to answer common jQuery questions, that there are certain practices using javascript, instead of jQuery, that actually enable you to write less and do ... well the same amount. And may also yield performance benefits. A specific example $(this) vs this Inside a click event referencing the clicked objects id jQuery $(this).attr("id"); Javascript this.id; Are there any other common practices like this? Where certain Javascript operations could be accomplished easier, without bringing jQuery into the mix. Or is this a rare case? (of a jQuery "shortcut" actually requiring more code) EDIT : While I appreciate the answers regarding jQuery vs. plain javascript performance, I am actually looking for much more quantitative answers. While using jQuery, instances where one would actually be better off (readability/compactness) to use plain javascript instead of using $(). In addition to the example I gave in my original question.

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• What's currently the best way to extend Excel using C#?

  - by user169867

  I have the professional versions of VS2008 & VS2010. I wish to add a couple buttons to a toolbar in Excel. When they are clicked I'd like to be able to open a form (either WinForms or WPF is fine) collect a few values from the user in the form and then take that data + read cell values from the current worksheet to perform some database operations. What's currently the best way to do this using C#? I'd greatly appreciate a pointer to any examples / tutorials. My understanding is that VS2010 has improved the process alot but I may have to deal w/ Excel 2003 which I don't think it supports. I get confused between Visual Studio 2008s Extensibility-Shared Addin template and other Office Addin templates I've seen. I'm not sure when which type of solution is appropriate. I'm new to Office development so I'd really appreciate any help to get me going on the right track. Thanks much.

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• Implementing DRY Forms

  - by virtualeyes

  Getting into Play 2.0, overall, blown away, great stuff. Anyway, wondering how one can achieve DRY forms in Play? If you look at the create & edit examples in the Computer Database Sample, you'll see that the form elements are repeated. With just 4 fields (in the sample form), no big deal, but when you're dealing with large, complex forms and/or handling many CRUD models, the duplication becomes a bigger maintenance issue. On the binding end ( form.bindFromRequest and form.fill(Foo) ), the implementation is so elegant for create/edit operations; is there a corresponding solution in the template layer?

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• How can i add an image in html email from lotus domino agent?

  - by mike_x_

  i want to add a simple image into an email which i want to send from a lotus agent. I paste below a part of the code: StringBuilder sb = new StringBuilder(); sb.append("<div><img src=\"http://goo.gl/lziMZN\"></div>"); email.setHTMLPart(sb.toString()); email.send("[email protected]"); I also tried to use an image from my image resources in the nsf. Whatever i tried i get an empty image area (browser-no-image icon) in the email i receive. I also have checked "Allow restricted operations" in my agent. I would prefer it if there is a solution to use an image from my resources and not an external link. Any solutions?

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• Can I use/include gsdll32.dll redmonnt.dll (no modifications) in a commercial application for my cli

  - by scriptmaster

  I am not a license expert; however, after a lot of research, I am still struggling to answer the following questions and would like to know if my assumptions are right! Is it legal to include gsdll32.dll and redmonnt.dll in a commercial product? Should I release any source code of the commercial app where I am using this library? Is there a commercial license (a small fee that my client can pay to use these libraries) to GhostScript? What are the alternative solutions?

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• What are some of the useful concepts to know about when building Silverlight apps?

  - by cody

  The Silverlight(& WPF) space seems to have a whole new nomenclature around it so at times I'm having a hard time figuring our what is important and useful to research a bit more. For example I 'know' about the MVVM pattern but I'm looking for things that are a bit smaller in scope, that is topics, ideas, programming constructs that might be used in implementing MVVM and would need to know before hand. So basically I'm looking for some of the key topics and concepts that people have found useful or are important when creating a Silverlight apps. And maybe why it is useful or important and when\where it might be applied or used. Thanks.

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• Help me understand Dispose() implementation code from MSDN

  - by Benny

  the following code is from MSDN: Idisposable pattern protected virtual void Dispose(bool disposing) { // If you need thread safety, use a lock around these // operations, as well as in your methods that use the resource. if (!_disposed) { if (disposing) { if (_resource != null) _resource.Dispose(); Console.WriteLine("Object disposed."); } // Indicate that the instance has been disposed. _resource = null; _disposed = true; } } why the following statement: _resource = null; _disposed = true; are not enclosed by if (disposing) statement block? for me i would probably write like this: if (disposing) { if (_resource != null) { _resource.Dispose(); _resource = null; _disposed = true; } Console.WriteLine("Object disposed."); } anything wrong with my version?

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• Primary reasons why programming language runtimes use stacks?

  - by manuel aldana

  Many programming language runtime environments use stacks as their primary storage structure (e.g. see JVM bytecode to runtime example). Quickly recalling I see following advantages: Simple structure (pop/push), trivial to implement Most processors are anyway optimized for stack operations, so it is very fast Less problems with memory fragmentation, it is always about moving memory-pointer up and down for allocation and freeing complete blocks of memory by resetting the pointer to the last entry offset. Is the list complete or did I miss something? Are there programming language runtime environments which are not using stacks for storage at all?

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• Can this loop be sped up in pure Python?

  - by Noctis Skytower

  I was trying out an experiment with Python, trying to find out how many times it could add one to an integer in one minute's time. Assuming two computers are the same except for the speed of the CPUs, this should give an estimate of how fast some CPU operations may take for the computer in question. The code below is an example of a test designed to fulfill the requirements given above. This version is about 20% faster than the first attempt and 150% faster than the third attempt. Can anyone make any suggestions as to how to get the most additions in a minute's time span? Higher numbers are desireable. EDIT: This experiment is being written in Python 3.1 and is 15% faster than the fourth speed-up attempt. def start(seconds): import time, _thread def stop(seconds, signal): time.sleep(seconds) signal.pop() total, signal = 0, [None] _thread.start_new_thread(stop, (seconds, signal)) while signal: total += 1 return total if __name__ == '__main__': print('Testing the CPU speed ...') print('Relative speed:', start(60))

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• Sql Server 2000 Stored Procedure Prevent Parallelism or something?

  - by user187305

  I have a huge disgusting stored procedure that wasn't slow a couple months ago, but now is. I barely know what this thing does and I am in no way interested in rewriting it. I do know that if I take the body of the stored procedure and then declare/set the values of the parameters and run it in query analyzer that it runs more than 20x faster. From the internet, I've read that this is probably due to a bad cached query plan. So, I've tried running the sp with "WITH RECOMPILE" after the EXEC and I've also tried putting the "WITH RECOMPLE" inside the sp, but neither of those helped even a little bit. When I look at the execution plan of the sp vs the query, the biggest difference is that the sp has "Parallelism" operations all over the place and the query doesn't have any. Can this be the cause of the difference in speeds? Thank you, any ideas would be great... I'm stuck.

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• What data is actually stored in a B-tree database in CouchDB?

  - by Andrey Vlasovskikh

  I'm wondering what is actually stored in a CouchDB database B-tree? The CouchDB: The Definitive Guide tells that a database B-tree is used for append-only operations and that a database is stored in a single B-tree (besides per-view B-trees). So I guess the data items that are appended to the database file are revisions of documents, not the whole documents: +---------|### ... | | +------|###|------+ ... ---+ | | | | +------+ +------+ +------+ +------+ | doc1 | | doc2 | | doc1 | ... | doc1 | | rev1 | | rev1 | | rev2 | | rev7 | +------+ +------+ +------+ +------+ Is it true? If it is true, then how the current revision of a document is determined based on such a B-tree? Doesn't it mean, that CouchDB needs a separate "view" database for indexing current revisions of documents to preserve O(log n) access? Wouldn't it lead to race conditions while building such an index? (as far as I know, CouchDB uses no write locks).

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• Tridion Core Service - Transaction roll back isnt working

  - by Tamir Lahav

  We are using the core service in ASP.NET custom page in order to create pages and components and sevenral updates (checkout,save and chekin). we want those operations to work in transaction, we tried to implement it acording to some examples over the net. However we didn't succeded operating the rollback. It seems that the operation are immediately performed without waiting for the comit . The code we used for simple check out - roll back operation for example is TransactionOptions txOptions = new TransactionOptions { IsolationLevel = IsolationLevel.ReadCommitted }; using (TransactionScope scope = new TransactionScope( TransactionScopeOption.Required, txOptions)) { using (CoreService2010Client m_client = new CoreService2010Client()) { PageData pp = m_client.CheckOut("tcm:309-36311-64", false, new ReadOptions()) as PageData; } scope.Dispose(); } We also added this recomended configuration to the web config bindings section What are we missing ?

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• How to have Load balanced web services sending messages with nservicebus to multiple subscribers ?

  - by Mrt

  I have load balanced web servers, that with the existing code base, handles when a user logs into the site. I would like to send a broadcast message to any applications that have subscribed saying 'hey x logged in' ? So have many web servers and many applications subscribing. How does discovery work/configuration work with nservicebus ? Should each application know about each web server and subscribe individually or is this where the distributer comes in, so web servers all send to the 1 distributer and all application subscribe to single distributer and the distributer relays the message ? I've tried to research this, but having troubles. Thanks MrT

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• Can I turn off implicit Python unicode conversions to find my mixed-strings bugs?

  - by Tal Weiss

  When profiling our code I was surprised to find millions of calls to C:\Python26\lib\encodings\utf_8.py:15(decode) I started debugging and found that across our code base there are many small bugs, usually comparing a string to a unicode or adding a sting and a unicode. Python graciously decodes the strings and performs the following operations in unicode. How kind. But expensive! I am fluent in unicode, having read Joel Spolsky and Dive Into Python... I try to keep our code internals in unicode only. My question - can I turn off this pythonic nice-guy behavior? At least until I find all these bugs and fix them (usually by adding a u'u')? Some of them are extremely hard to find (a variable that is sometimes a string...). Python 2.6.5 (and I can't switch to 3.x).

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• Known problems with filemtime() on Windows - files getting touched arbitrarily?

  - by Pekka

  Is there a known issue leading to file modification times of cache files on Windows XP SP 3 getting arbitrarily updated, but without any actual change? Is there some service on a standard Windows XP - Backup, Sync, Versioning, Virus scanner - known to touch files? They all have a .txt extension. If there isn't, forget it. Then I'm getting something wrong in my cache routines, and I'll debug my way through. Background: I'm building a simple caching wrapper around a slow web site on a Windows server. I am comparing the filemtime() time stamp to some columns in the data base to determine whether a cached file is stale. I'm having problems using this method because the modification time of the cache files seems to get updated in between operations without me doing anything. THis results in stale files being displayed. I'm the only user on the machine. The operating system is Windows XP, the webserver a XAMPP Apache 2 with PHP 5.2

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• How to use a object whose copy constructor and copy assignment is private?

  - by coanor

  In reading TCPL, I got a problem, as the title refered, and then 'private' class is: class Unique_handle { private: Unique_handle& operator=(const Unique_handle &rhs); Unique_handle(const Unique_handle &rhs); public: //... }; the using code is: struct Y { //... Unique_handle obj; }; and I want to execute such operations: int main() { Y y1; Y y2 = y1; } although, these code are come from TCPL, but I still can not got the solution... Can anybody help me, appreciate.

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• Switch to BigInteger if necessary

  - by fahdshariff

  I am reading a text file which contains numbers in the range [1, 10^100]. I am then performing a sequence of arithmetic operations on each number. I would like to use a BigInteger only if the number is out of the int/long range. One approach would be to count how many digits there are in the string and switch to BigInteger if there are too many. Otherwise I'd just use primitive arithmetic as it is faster. Is there a better way? Is there any reason why Java could not do this automatically i.e. switch to BigInteger if an int was too small? This way we would not have to worry about overflows.

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• sorting a list of objects by value php

  - by Mike

  I have a list of objects: class Beer { var $name; var $id; var $style; var $brewery; var $rate; function getName() { return $this->name; } function getID() { return $this->id; } function getStyle() { return $this->style; } function getBrewery() { return $this->brewery; } function getRate() { return $this->rate; } } After doing some research online on how to accomplish this, this is my code: usort($localBeersList, "cmp"); function cmp($a, $b) { if ($a->getRate() == $b->getRate()) { return 0; } return ($a->getRate() < $b->getRate()) ? -1 : 1; } If I try and output my list after this I do not get anything.

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• isReachable in Java doesn't appear to be working quite the way it's supposed to

  - by Rayne

  I'm using Clojure, but I can read Java, so this isn't a Clojure specific question. This doesn't even seem to be working from Java. I'm trying to implement a bit of a 'ping' function using isReachable. The code I'm using is this: (.isReachable (java.net.InetAddress/getByName "www.microsoft.com") 5000) Translated to Java by a good friend of mine: public class NetTest { public static void main (String[] args) throws Exception{ String host = "acidrayne.net"; InetAddress a = InetAddress.getByName(host); System.out.println(a.isReachable(10000)); } } Both of these return false. I suppose I must be doin' it wrong, but Google research is telling me differently. I'm confuzzled!

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• Session troubles when used on BT hosting

  - by YsoL8

  Hello I have developed a site for a client with a pre-existing BT hosting package. Since going live there has been a problem where $_session loses it's data between pages. I have previously fixed the problem, but somehow it has become unfixed. Last time this problem happened, my research indicated that there is something funny with BT's setup when using sessions, and that article provided this code: if(ini_get('register_globals') == 1) if(is_array($_SESSION)) foreach(array_keys($_SESSION) as $var_to_kill) unset($$var_to_kill); Which even though it looks broken to me, did in fact reduce the problem to a very low level. (i.e one drop out a day). However, today my client is in touch again and surprise surprise, the problem is back. Does anyone know of a solution? (My client has already stated they will not change hosts!) Oliver

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• PHP/MySQL: Storing and retrieving UUIDS

  - by Greg

  I'm trying to add UUIDs to a couple of tables, but I'm not sure what the best way to store/retrieve these would be. I understand it's far more efficient to use BINARY(16) instead of VARCHAR(36). After doing a bit of research, I also found that you can convert a UUID string to binary with: UNHEX(REPLACE(UUID(),'-','')) Pardon my ignorance, but is there an easy way to this with PHP and then turn it back to a string, when needed, for readability? Also, would it make much difference if I used this as a primary key instead of auto_increment? EDIT: Found part of the answer: $bin = pack("h*", str_replace('-', '', $guid)); How would you unpack it?

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