Search Results

Search found 10536 results on 422 pages for 'cpu usage'.

Page 297/422 | < Previous Page | 293 294 295 296 297 298 299 300 301 302 303 304  | Next Page >

• How to initialize an std::string using ""?

  - by Mohsin

  I'm facing problems with initializing a std::string variable using "" (i.e. an empty string). It's causing strange behavior in code that was previously working. Is the following statement wrong? std::string operationalReason = ""; When I use the following code everything works fine: std::string operationalReason; operationalReason.clear(); I believe that string literals are stored in a separate memory location that is compiler-dependent. Could the problem I'm seeing actually be indicating a corruption of that storage? If so, it would get hidden by my usage of the clear() function. Thanks.

  Read the article

• Possible to distribute an MPI (C++) program accross the internet rather than within a LAN cluster?

  - by Ben

  Hi there, I've written some MPI code which works flawlessly on large clusters. Each node in the cluster has the same cpu architecture and has access to a networked (i.e. 'common') file system (so that each node can excecute the actual binary). But consider this scenario: I have a machine in my office with a dual core processor (intel). I have a machine at home with a dual core processor (amd). Both machines run linux, and both machines can successfully compile and run the MPI code locally (i.e. using 2 cores). Now, is it possible to link the two machines together via MPI, so that I can utilise all 4 cores, bearing in mind the different architectures, and bearing in mind the fact that there are no shared (networked) filesystems? If so, how? Thanks, Ben.

  Read the article

• MySQL Locking Up

  - by Ian

  I've got a innodb table that gets a lot of reads and almost no writes (like, 1 write for every 400,000 reads approx). I'm running into a pretty big problem though when I do INSERT into the table. MySQL completely locks up. It uses 100% cpu, and every single other table (in other databases even) have their statuses set to "Locked" until the INSERT is done. This is a big problem because MySQL stays locked up for up to 4 minutes. I'm using version 5.1.47 (rpm from mysql.com). Any ideas?

  Read the article

• Jelly bean not calling onPrepareOptionsMenu() when opening the menu for the first time

  - by syloc

  I'm overriding onPrepareOptionsMenu to hide and show menu items. When testing it with the API level 16 emulator; onPrepareOptionsMenu is not called when opening the menu for the first time. But when i reopen the menu it works. The problem is only with the first usage. You can simple test it with this; @Override public void onPrepareOptionsMenu(Menu menu) { Toast.makeText(this.getActivity(), "pre", Toast.LENGTH_SHORT).show(); super.onPrepareOptionsMenu(menu); } Any ideas?

  Read the article

• HTML Audio performance

  - by user1888309

  I'm working on HTML drum machine, and I`ve met some performance issues, rhythm start to break if BPM is higher than 110 but I'm expecting to make it work on BPM over 180. I guess that it can be related with format or codec of audio files, however it also maybe that my code is not very optimised (as I can see from JS CPU profiling it's not). So I'm expecting you guys give me some code review or some hints on optimisation. Although all similar projects I've found on internet didn't work good and maybe it's just restrictions of Audio API. By the way, it's very raw and sounds works only on Chrome under Mac OS, so any advise on audio encoding for web also would be great Project on Github pages Screenshot of Groove which breaks UPDATE Ok, I've found that I was encoding audio files incorrectly, after fixing that rhythm stopped breaking, and also it started working in Mozilla. But still there are issues on windows OS.

  Read the article

• Recreation of DB using "mysql mydb < mydb.sql" is really slow when the table has tens of millions of

  - by Jian Lin

  It seems that a MySQL database that has a table with tens of millions of records will get a big INSERT INTO statement when the following mysqldump some_db > some_db.sql is done to back up the database. (is it 1 insert statement that handles all the records?) So when reconstructing the DB using mysql some_db < some_db.sql then the CPU is hardly busy (about 1.8% usage by the mysql process... I don't see a mysqld either?) and also the hard disk doesn't seem to be too busy... Last time, the whole restore process took 5 hours. Is there a way to make it faster? Such as, when doing mysqldump, can it break the INSERT statement into shorter ones, so that the mysql doesn't need to parse the line so hard when restoring the DB?

  Read the article

• Javscript filter vs map problem

  - by graham.reeds

  As a continuation of my min/max across an array of objects I was wondering about the performance comparisons of filter vs map. So I put together a test on the values in my code as was going to look at the results in FireBug. This is the code: var _vec = this.vec; min_x = Math.min.apply(Math, _vec.filter(function(el){ return el["x"]; })); min_y = Math.min.apply(Math, _vec.map(function(el){ return el["x"]; })); The mapped version returns the correct result. However the filtered version returns NaN. Breaking it out, stepping through and finally inspecting the results, it would appear that the inner function returns the x property of _vec but the actual array returned from filter is the unfiltered _vec. I believe my usage of filter is correct - can anyone else see my problem?

  Read the article

• PagedDataSource does not support serialization - how can I enforce this ?

  - by Darkyo

  Sounds like I want to override a physics law, but at least it is the most reasonnable solution, cpu / HDD and Ram effective for my asp.net project. In fact, I got a pageddataSource and a customDataReader that supports paginated data. The truth is my data are in a viewstate variable, because it is re-used in an update panel. When I intend to use it into my pageddatasource, asp.net 3.5 kills me with a System.Web.UI.WebControls.PagedDataSource' in Assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not marked as serializable. cool exception... So I'd rather not offend newton because I know he'll always win, but I would need some help to enforce this pagedDataSource law, that seems so unbelievable, except if someone has an explanation.

  Read the article

• IO completion port key confusion

  - by Richard Tew

  I'm writing an IO completion port based server (source code here) using the Windows DLL API in Python using the ctypes module. But this is a pretty direct usage of the API and this question is directed at those who have a knowledge of IOCP, not Python. As I understand the documentation for CreateIoCompletionPort, you specify your "user defined" completion key when you call this function with a file handle (in my case a socket) you are associating with the created IOCP. When you get around to calling GetQueuedCompletionStatus, you get a completion key value along with a pointer to an overlapped object. The completion key should identify what overlapped object and request has completed. However, let's say I pass in 100 as the completion key in my CreateIoCompletionPort call with an overlapped object. When the same overlapped object has its IO completed and it arrives back through GetQueuedCompletionStatus, the completion key that accompanies it is much larger and bares no resemblance to the original value of 100. Am I misunderstanding how the completion key works, or must I be doing it wrong in the source code I linked above?

  Read the article

• Why does order matter for ImageMagick's -colorspace operation?

  - by Mark Trapp

  Starting with ImageMagick 6, the command style changed to solve a bunch of problems outlined in the Basic Usage document. That document does imply that for simple operations, one should only need to move the options from before the source file to between the source and output files to convert from the "old" style to the "new" style. However, this doesn't seem to work for the -colorspace operation. When I use the following command, I get an output file with the correct colors: convert -colorspace rgb input.pdf output.png But when I try to use the new command style, the -colorspace operation is never applied: convert input.pdf -colorspace rgb output.png Samples: Why does this occur?

  Read the article

• Intersection of sets Mongodb

  - by afvasd

  Hi everyone I am new to mongo, this is my db design: product := { name: str group: ref, comments: [ ref, ref, ref, ref ] } comments := { ... a bunch of comments stuff } tag := { _id: int, #Need this for online requests tag: str, products: [ {product: ref, score: float}, ... ], comments: [ {comment: ref, score: float}, ...], } So my usage pattern is: GIVEN a product, find comments that have certain tag and sort them accordingly. My current approach involves: Look for that tag object that has tag=myTag pull all the comments out, sorted look for that product where product.name=myProduct pull all the comments out (which are dbrefs by the way) loop through the result of 2, and checking if they are in 4, (this I can do a limit 10) etc. It's pretty inefficient. Any better methods?

  Read the article

• What is the optimal number of threads for performing IO operations in java?

  - by marc

  In Goetz's "Java Concurrency in Practice", in a footnote on page 101, he writes "For computational problems like this that do not I/O and access no shared data, Ncpu or Ncpu+1 threads yield optimal throughput; more threads do not help, and may in fact degrade performance..." My question is, when performing I/O operations such as file writing, file reading, file deleting, etc, are there guidelines for the number of threads to use to achieve maximum performance? I understand this will be just a guide number, since disk speeds and a host of other factors play into this. Still, I'm wondering: can 20 threads write 1000 separate files to disk faster than 4 threads can on a 4-cpu machine?

  Read the article

• C inline assembly of x96 fbstp instruction

  - by David HUnter

  Was wondering how to inline a usage of fbstp on a 32 bit I86 architecture. I tried something like int main( ) { double foo = 100.0; long bar = 0; asm( "pushl %1; fbstp %0" : "=m"(bar) : "r"(foo) ); ... But bar is unchanged. I have tried reading everything I can find on this but most example simply do things like add two integers together. I can’t find any that talk about pushing operands onto the stack and what I should be doing when an instruction like fbstp writes 80 bits of data back to memory ( i.e. what C type to use ) and how to specify it in the asm syntax. Also on x86-64 there seems to be a pushq and no pushl but fbstp still exists whereas fbstq does not. Is there some other magic for 64 bit.

  Read the article

• View a SYS.XMLTYPE returned from an Oracle function, using PL/SQL

  - by caerphilly

  I have an Oracle function that dynamically creates an XML document, and returns it in a SYS.XMLTYPE value. I want to run a query from SQL Developer that calls that function and prints the document (either via a select, or dbms_output - I don't care). But all the examples/documentation seem to refer to querying XML columns in tables, and I can't seem to get the syntax right for my particular usage. I'd like something like this: declare x SYS.XMLTYPE; begin x := my_package.my_function(); select x.getclobval() from x; -- doesn't work! end; How can I print out the value of the XML type variable 'x' in the above code?

  Read the article

• Proper way to have an endless worker thread?

  - by Neil N

  I have an object that requires a lot of initialization (1-2 seconds on a beefy machine). Though once it is initialized it only takes about 20 miliseconds to do a typical "job" In order to prevent it from being re-initialized every time an app wants to use it (which could be 50 times a second or not at all for minutes in typical usage), I decided to give it a job que, and have it run on its own thread, checking to see if there is any work for it in the que. However I'm not entirely sure how to make a thread that runs indefinetly with or without work. Here's what I have so far, any critique is welcomed private void DoWork() { while (true) { if (JobQue.Count > 0) { // do work on JobQue.Pop() } else { System.Threading.Thread.Sleep(50); } } } After thought: I was thinking I may need to kill this thread gracefully insead of letting it run forever, so I think I will add a Job type that tells the thread to end. Any thoughts on how to end a thread like this also appreciated.

  Read the article

• Inheriting the main method

  - by Eric

  I want to define a base class that defines a main method that instantiates the class, and runs a method. There are a couple of problems though. Here is the base class: public abstract class Strategy { abstract void execute(SoccerRobot robot); public static void main(String args) { Strategy s = new /*Not sure what to put here*/(); s.execute(new SoccerRobot()) } } And here is an example derived class: public class UselessStrategy { void execute(SoccerRobot robot) { System.out.println("I'm useless") } } It defines a simple execute method, which should be called in a main method upon usage as a the main application. However, in order to do so, I need to instantiate the derived class from within the base class's main method. Which doesn't seem to be possible. I'd rather not have to repeat the main method for every derived class, as it feels somewhat unnessary. Is there a right way of doing this?

  Read the article

• Is ActiveMQ unreliable?

  - by user122991

  Hello, We have been using ActiveMQ 5.2 in our distributed enterprise application for about 3 months. During that time, we have experienced debilitating failures at least twice weekly. In particular, we see: 1) Topic publisher has its connection arbitrarily closed and experiences EOF on attempt to publish. Note well that this issue is not a function of some timeout. It does not correlate reliably with any inactivity. 2) Queue listeners never receive message. Message simply sits on Queue. 2) is much rarer (hardly ever) than 1). In both cases, the failures are highly intermittent-- they cannot be reliably reproduced through any testing usage pattern. Also, there are no errors or warning in the AMQ logs. Have others experienced similar problems? Is there an opinion that some other JMS provider is more reliable? thanks, Joe

  Read the article

• Determining which classes would benefit most from unit testing?

  - by benoit

  I am working on a project where we have only 13% of code coverage with our unit tests. I would like to come up with a plan to improve that but by focusing first on the areas where increasing coverage would bring the greatest value. This project is in C#, we're using VS 2008 and TFS 2008 and out unit tests are written using MSTest. What methodology should I use to determine which classes we should tackle first? Which metrics (code or usage) should I be looking at (and how can I get those metrics if this is not obvious)?

  Read the article

• jQuery.keypad Performance Issues

  - by John Duff

  I am working on a Kiosk Touch Screen application and using the JQuery.keypad plugin and noticing some major performance issues. If you click a number of buttons in rapid succession the CPU gets pegged, the button clicks don't keep up with the clicking and some button presses even get lost. On my dev machine this isn't as noticeable, but on the Kiosk itself with 1 gig of ram it's painful. Trying the demo keypad at http://keith-wood.name/keypad.html#inline the one with multiple targets (which is the case with mine) has the exact same issues. Does anyone have any suggestions on how we might be able to improve this? The Kiosk runs in Firefox only so something specific to that would work. I'm using v1.2.1 of jquery.keypad and just upgraded to v1.4.2 of jquery.

  Read the article

• How can one manage to fully use the newly enhanced Parallelism features in .NET 4.0?

  - by Will Marcouiller

  I am pretty much interested into using the newly enhanced Parallelism features in .NET 4.0. I have also seen some possibilities of using it in F#, as much as in C#. Despite, I can only see what PLINQ has to offer with, for example, the following: var query = from c in Customers.AsParallel() where (c.Name.Contains("customerNameLike") select c; There must for sure be some other use of this parallelism thing. Have you any other examples of using it? Is this particularly turned toward PLINQ, or are there other usage as easy as PLINQ? Thanks! =)

  Read the article

• Common Programming Jargon

  - by jdk

  What programming terms have you coined (or heard) that have taken off in your own circles (i.e. have heard others repeat it)? It might be within your own team, workplace or garnered greater popularity on the Internet. Write your programming term, word or phrase in bold text followed by an explanation, citation and/or usage example so we can use it in appropriate context. Please no repeats of common jargon already ingrained in the programming culture like: "kludge", "automagically", "cruft", etc. (unless you coined it). Stealing from the comments: "A shared vocabulary is the basis of communication, not just among programmers [...]"

  Read the article

• How to create real-life robots?

  - by Click Upvote

  Even before I learnt programming I've been fascinated with how robots could work. Now I know how the underlying programming instructions would be written, but what I don't understand is how those intructions are followed by the robot. For example, if I wrote this code: object=Robot.ScanSurroundings(300,400); if (Objects.isEatable(object)) { Robot.moveLeftArm(300,400); Robot.pickObject(object); } How would this program be followed by the CPU in a way that would make the robot do the physical action of looking to the left, moving his arm, and such? Is it done primarily in binary language/ASM? Lastly, where would i go if I wanted to learn how to create a robot?

  Read the article

• Does the number of busy worker threads in the CLR ThreadPool affect performance of I/O threads?

  - by andrej351

  We have a Windows Service which hosts a number of WCF services and, in an unrelated part of the app, makes extensive use of the TPL Task class to asynchronously do relatively short bits of work. It is my understanding that WCF uses managed I/O threads from the ThreadPool to execute requests. I noticed that after deploying a feature which significantly raised the applications use of Tasks, and as such the use of ThreadPool worker threads as well, performance of a couple of web services has become very slow. We're talking minutes instead of less than a second. The number of Tasks actually trying to run at any one time can range between 20 and 1000, which makes me think that any new (last in) work needing some CPU time could be forced to wait for quite some time. Does the (in my case extremely large) number of busy ThreadPool worker threads affect the ThreadPool's managed I/O threads? Or could these two be connected in any way? Thanks!

  Read the article

• Why implement DB connection pointer object as a reference counting pointer? (C++)

  - by DVK

  At our company one of the core C++ classes (Database connection pointer) is implemented as a reference counting pointer. To be clear, the objects are NOT DB connections themselves, but pointers to a DB connection object. The library is very old, and nobody who designed is around anymore. So far, nether I, nor any C++ experts in the company that I asked have come up with a good reason for why this particular design was chosen. Any ideas? It is introducing some problems (partially due to awful reference pointer implementation used), and I'm trying to understand if this design actually has some deep underlying reasons? The usage pattern these days seems to be that the DB connection pointer object is returned by a DB connection manager class, and it's somewhat unclear whether DB connection pointers were designed to be able to be used independently of DB connection manager.

  Read the article

• Why doesn't infinite recursion hit a stack overflow exception in F#?

  - by Amazingant

  I know this is somewhat the reverse of the issue people are having when they ask about a stack overflow issue, but if I create a function and call it as follows, I never receive any errors, and the application simply grinds up a core of my CPU until I force-quit it: let rec recursionTest x = recursionTest x recursionTest 1 Of course I can change this out so it actually does something like this: let rec recursionTest (x: uint64) = recursionTest (x + 1UL) recursionTest 0UL This way I can occasionally put a breakpoint in my code and see the value of x is going up rather quickly, but it still doesn't complain. Does F# not mind infinite recursion?

  Read the article

< Previous Page | 293 294 295 296 297 298 299 300 301 302 303 304  | Next Page >