Search Results

Search found 27144 results on 1086 pages for 'tail call optimization'.

Page 399/1086 | < Previous Page | 395 396 397 398 399 400 401 402 403 404 405 406  | Next Page >

• Why is cell phone software is still so primitive?

  - by Tomislav Nakic-Alfirevic

  I don't do mobile development, but it strikes me as odd that features like this aren't available by default on most phones: full text search: searches all address book contents, messages, anything else being a plus better call management: e.g. a rotating audio call log, meaning you always have the last N calls recorded for your listening pleasure later (your little girl just said her first "da-da" while you were on a business trip, you had a telephone job interview, you received complex instructions to do something etc.) bluetooth remote control (like e.g. anyRemote, but available by default on a bluetooth phone) no multitasking capabilities worth mentioning and in general no e.g. weekly software updates, making the phone much more usable (even if it had to be done over USB, rather than over the network). I'm sure I was dumbfounded by the lack or design of other features as well, but they don't come to mind right now. To clarify, I'm not talking about smartphones here: my plain, 2-year old phone has a CPU an order of magnitude faster than my first PC, about as much storage space and it's ridiculous how bad (slow, unwieldy) the software is and it's not one phone or one manufacturer. What keeps the (to me) obvious software functionality vacuum on a capable hardware platform from being filled up?

  Read the article

• In languages which create a new scope each time in a loop block, a new local copy of the local loop

  - by Jian Lin

  It seems that in language like C, Java, and Ruby (as opposed to Javascript), a new scope is created for each iteration of a loop block, and the local variable defined for the loop is actually made into a local variable every single time and recorded in this new scope? For example, in Ruby: p RUBY_VERSION $foo = [] (1..5).each do |i| $foo[i] = lambda { p i } end (1..5).each do |j| $foo[j].call() end the print out is: [MacBook01:~] $ ruby scope.rb "1.8.6" 1 2 3 4 5 [MacBook01:~] $ So, it looks like when a new scope is created, a new local copy of i is also created and recorded in this new scope, so that when the function is executed at a later time, the "i" is found in those scope chains as 1, 2, 3, 4, 5 respectively. Is this true? (It sounds like a heavy operation). Contrast that with p RUBY_VERSION $foo = [] i = 0 (1..5).each do |i| $foo[i] = lambda { p i } end (1..5).each do |j| $foo[j].call() end This time, the i is defined before entering the loop, so Ruby 1.8.6 will not put this i in the new scope created for the loop block, and therefore when the i is looked up in the scope chain, it always refer to the i that was in the outside scope, and give 5 every time: [MacBook01:~] $ ruby scope2.rb "1.8.6" 5 5 5 5 5 [MacBook01:~] $ I heard that in Ruby 1.9, i will be treated as a local defined for the loop even when there is an i defined earlier? The operation of creating a new scope, creating a new local copy of i each time through the loop seems heavy, as it seems it wouldn't have matter if we are not invoking the functions at a later time. So when the functions don't need to be invoked at a later time, could the interpreter and the compiler to C / Java try to optimize it so that there is not local copy of i each time?

  Read the article

• Windows Task Scheduler: IAction.QueryInterface() returns an error I cannot find a definition for

  - by Sascha

  Hello I am attempting to schedule a task (to open an .exe at a specific time) using C++ win32. But at one specific point I am getting an error, I have searched & searched to try & find the definition of this error but I cannot find it? Do you know what this error means: Hexadecimal: 80004003 Decimal: 2147500035 I wont post the whole function because its rather long (unless you may need it to determine the error context?). The code I am using (that causes the error) is the following: // QI for the executable task pointer. hr = action -> QueryInterface( IID_IExecAction, (void**) execAction ); action -> Release(); if( FAILED(hr) ) { printf("QueryInterface call failed for IExecAction: %x %X %u \n", hr, hr, hr ); rootFolder -> Release(); task -> Release(); CoUninitialize(); return false; } The output is: QueryInterface call failed for IExecAction: 80004003 80004003 2147500035

  Read the article

• url with question mark considered as new http request?

  - by Navin Leon

  I am optimization my web page by implementing caching, so if I want the browser not to take data from cache, then I will append a dynamic number as query value. eg: google.com?val=823746 But some time, if I want to bring data from cache for the below url, the browser is making a new http request to server, its not taking data from cache. Is that because of the question mark in URL ? eg: http://google.com? Please provide some reference document link. Thanks in advance. Regards, Navin

  Read the article

• instantiate python object within a c function called via ctypes

  - by gwk

  My embedded Python 3.3 program segfaults when I instantiate python objects from a c function called by ctypes. After setting up the interpreter, I can successfully instantiate a python Int (as well as a custom c extension type) from c main: #import <Python/Python.h> #define LOGPY(x) \ { fprintf(stderr, "%s: ", #x); PyObject_Print((PyObject*)(x), stderr, 0); fputc('\n', stderr); } // c function to be called from python script via ctypes. void instantiate() { PyObject* instance = PyObject_CallObject((PyObject*)&PyLong_Type, NULL); LOGPY(instance); } int main(int argc, char* argv[]) { Py_Initialize(); instantiate(); // works fine // run a script that calls instantiate() via ctypes. FILE* scriptFile = fopen("emb.py", "r"); if (!scriptFile) { fprintf(stderr, "ERROR: cannot open script file\n"); return 1; } PyRun_SimpleFileEx(scriptFile, scriptPath, 1); // close on completion return 0; } I then run a python script using PyRun_SimpleFileEx. It appears to run just fine, but when it calls instantiate() via ctypes, the program segfaults inside PyObject_CallObject: import ctypes as ct dy = ct.CDLL('./emb') dy.instantiate() # segfaults lldb output: instance: 0 Process 52068 stopped * thread #1: tid = 0x1c03, 0x000000010000d3f5 Python`PyObject_Call + 69, stop reason = EXC_BAD_ACCESS (code=1, address=0x18) frame #0: 0x000000010000d3f5 Python`PyObject_Call + 69 Python`PyObject_Call + 69: -> 0x10000d3f5: movl 24(%rax), %edx 0x10000d3f8: incl %edx 0x10000d3fa: movl %edx, 24(%rax) 0x10000d3fd: leaq 2069148(%rip), %rax ; _Py_CheckRecursionLimit (lldb) bt * thread #1: tid = 0x1c03, 0x000000010000d3f5 Python`PyObject_Call + 69, stop reason = EXC_BAD_ACCESS (code=1, address=0x18) frame #0: 0x000000010000d3f5 Python`PyObject_Call + 69 frame #1: 0x00000001000d5197 Python`PyEval_CallObjectWithKeywords + 87 frame #2: 0x0000000201100d8e emb`instantiate + 30 at emb.c:9 Why does the call to instantiate() fail from ctypes only? The function only crashes when it calls into the python lib, so perhaps some interpreter state is getting munged by the ctypes FFI call?

  Read the article

• Python3 and ftplib uploading files

  - by Teifion

  My python2 script uploads files nicely using this method but python3 is presenting problems and I'm stuck as to where to go next (googling hasn't helped). from ftplib import FTP ftp = FTP(ftp_host, ftp_user, ftp_pass) ftp.storbinary('STOR myfile.txt', open('myfile.txt')) The error I get is Traceback (most recent call last): File "/Library/WebServer/CGI-Executables/rob3/functions/cli_f.py", line 12, in upload ftp.storlines('STOR myfile.txt', open('myfile.txt')) File "/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/ftplib.py", line 454, in storbinary conn.sendall(buf) TypeError: must be bytes or buffer, not str I tried altering the code to from ftplib import FTP ftp = FTP(ftp_host, ftp_user, ftp_pass) ftp.storbinary('STOR myfile.txt'.encode('utf-8'), open('myfile.txt')) But instead I got this Traceback (most recent call last): File "/Library/WebServer/CGI-Executables/rob3/functions/cli_f.py", line 12, in upload ftp.storbinary('STOR myfile.txt'.encode('utf-8'), open('myfile.txt')) File "/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/ftplib.py", line 450, in storbinary conn = self.transfercmd(cmd) File "/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/ftplib.py", line 358, in transfercmd return self.ntransfercmd(cmd, rest)[0] File "/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/ftplib.py", line 329, in ntransfercmd resp = self.sendcmd(cmd) File "/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/ftplib.py", line 244, in sendcmd self.putcmd(cmd) File "/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/ftplib.py", line 179, in putcmd self.putline(line) File "/Library/Frameworks/Python.framework/Versions/3.1/lib/python3.1/ftplib.py", line 172, in putline line = line + CRLF TypeError: can't concat bytes to str Can anybody point me in the right direction

  Read the article

• jQuery - Callback failing if there is no options parameter

  - by user249950

  Hi, I'm attempting to build a simple plugin like this (function($) { $.fn.gpSlideOut = function(options, callback) { // default options - these are used when no others are specified $.fn.gpSlideOut.defaults = { fadeToColour: "#ffffb3", fadeToColourSpeed: 500, slideUpSpeed: 400 }; // build main options before element iteration var o = $.extend({}, $.fn.gpSlideOut.defaults, options); this.each(function() { $(this) .animate({backgroundColor: o.fadeToColour},o.fadeToColourSpeed) .slideUp(o.SlideUpSpeed, function(){ if (typeof callback == 'function') { // make sure the callback is a function callback.call(this); // brings the scope to the callback } }); }); return this; }; // invoke the function we just created passing it the jQuery object })(jQuery); The confusion I'm having is that normally on jQuery plugins you can call something like this: $(this_moveable_item).gpSlideOut(function() { // Do stuff }); Without the options parameter, but it misses the callback if I do it like that so I have to always have var options = {} $(this_moveable_item).gpSlideOut(options, function() { // Do stuff }); Even if I only want to use the defaults. Is there anyway to make sure the callback function is called whether or not the options parameter is there? Cheers.

  Read the article

• How can you handle cross-cutting conerns in JAX-WS without Spring or AOP? Handlers?

  - by LES2

  I do have something more specific in mind, however: Each web service method needs to be wrapped with some boiler place code (cross cutting concern, yes, spring AOP would work great here but it either doesn't work or unapproved by gov't architecture group). A simple service call is as follows: @WebMethod... public Foo performFoo(...) { Object result = null; Object something = blah; try { soil(something); result = handlePerformFoo(...); } catch(Exception e) { throw translateException(e); } finally { wash(something); } return result; } protected abstract Foo handlePerformFoo(...); (I hope that's enough context). Basically, I would like a hook (that was in the same thread - like a method invocation interceptor) that could have a before() and after() that could could soil(something) and wash(something) around the method call for every freaking WebMethod. Can't use Spring AOP because my web services are not Spring managed beans :( HELP!!!!! Give advice! Please don't let me copy-paste that boiler plate 1 billion times (as I've been instructed to do). Regards, LES

  Read the article

• mod_rewrite with question marks and ampersands (with PHP)

  - by Chris

  I have a PHP-based web app that I'm trying to apply Apache's mod_rewrite to. Original URLs are of the form: http://example.com/index.php?page=home&x=5 And I'd like to transform these into: http://example.com/home?x=5 Note that while rewriting the page name, I'm also effectively "moving" the question mark. When I try to do this, Apache happily performs this translation: RewriteRule ^/([a-z]+)\?(.+)$ /index.php?page=$1&$2 [NC,L] But it messes up the $_GET variables in PHP. For example, a call to http://example.com/home?x=88 yields only one $_GET variable (page => home). Where did x => 88 go? However, when I change my rule to use an ampersand rather than a question mark: RewriteRule ^/([a-z]+)&(.+)$ /index.php?page=$1&$2 [NC,L] a call like http://example.com/home&x=88 will work just as I'd expect it to (i.e. both the page and x $_GET variables are set appropriately). The difference is minimal I know, but I'd like my URL variables to "start" with a question mark, if it's possible. I'm sure this reflects my own misunderstanding of how mod_rewrite redirects interact with PHP, but it seems like I should be able to do this (one way or another). Thanks in advance! Cheers, -Chris

  Read the article

• Qt Socket blocking functions required to run in QThread where created. Any way past this?

  - by Alexander Kondratskiy

  The title is very cryptic, so here goes! I am writing a client that behaves in a very synchronous manner. Due to the design of the protocol and the server, everything has to happen sequentially (send request, wait for reply, service reply etc.), so I am using blocking sockets. Here is where Qt comes in. In my application I have a GUI thread, a command processing thread and a scripting engine thread. I create the QTcpSocket in the command processing thread, as part of my Client class. The Client class has various methods that boil down to writing to the socket, reading back a specific number of bytes, and returning a result. The problem comes when I try to directly call Client methods from the scripting engine thread. The Qt sockets randomly time out and when using a debug build of Qt, I get these warnings: QSocketNotifier: socket notifiers cannot be enabled from another thread QSocketNotifier: socket notifiers cannot be disabled from another thread Anytime I call these methods from the command processing thread (where Client was created), I do not get these problems. To simply phrase the situation: Calling blocking functions of QAbstractSocket, like waitForReadyRead(), from a thread other than the one where the socket was created (dynamically allocated), causes random behaviour and debug asserts/warnings. Anyone else experienced this? Ways around it? Thanks in advance.

  Read the article

• Calling PHP functions within HEREDOC strings

  - by Doug Kavendek

  In PHP, the HEREDOC string declarations are really useful for outputting a block of html. You can have it parse in variables just by prefixing them with $, but for more complicated syntax (like $var[2][3]), you have to put your expression inside {} braces. In PHP 5, it is possible to actually make function calls within {} braces inside a HEREDOC string, but you have to go through a bit of work. The function name itself has to be stored in a variable, and you have to call it like it is a dynamically-named function. For example: $fn = 'testfunction'; function testfunction() { return 'ok'; } $string = <<< heredoc plain text and now a function: {$fn()} heredoc; As you can see, this is a bit more messy than just: $string = <<< heredoc plain text and now a function: {testfunction()} heredoc; There are other ways besides the first code example, such as breaking out of the HEREDOC to call the function, or reversing the issue and doing something like: ?> <!-- directly outputting html and only breaking into php for the function --> plain text and now a function: <?PHP print testfunction(); ?> The latter has the disadvantage that the output is directly put into the output stream (unless I'm using output buffering), which might not be what I want. So, the essence of my question is: is there a more elegant way to approach this? Edit based on responses: It certainly does seem like some kind of template engine would make my life much easier, but it would require me basically invert my usual PHP style. Not that that's a bad thing, but it explains my inertia.. I'm up for figuring out ways to make life easier though, so I'm looking into templates now.

  Read the article

• BindingList<T> and reflection!

  - by Aren B

  Background Working in .NET 2.0 Here, reflecting lists in general. I was originally using t.IsAssignableFrom(typeof(IEnumerable)) to detect if a Property I was traversing supported the IEnumerable Interface. (And thus I could cast the object to it safely) However this code was not evaluating to True when the object is a BindingList<T>. Next I tried to use t.IsSubclassOf(typeof(IEnumerable)) and didn't have any luck either. Code /// <summary> /// Reflects an enumerable (not a list, bad name should be fixed later maybe?) /// </summary> /// <param name="o">The Object the property resides on.</param> /// <param name="p">The Property We're reflecting on</param> /// <param name="rla">The Attribute tagged to this property</param> public void ReflectList(object o, PropertyInfo p, ReflectedListAttribute rla) { Type t = p.PropertyType; //if (t.IsAssignableFrom(typeof(IEnumerable))) if (t.IsSubclassOf(typeof(IEnumerable))) { IEnumerable e = p.GetValue(o, null) as IEnumerable; int count = 0; if (e != null) { foreach (object lo in e) { if (count >= rla.MaxRows) break; ReflectObject(lo, count); count++; } } } } The Intent I want to basically tag lists i want to reflect through with the ReflectedListAttribute and call this function on the properties that has it. (Already Working) Once inside this function, given the object the property resides on, and the PropertyInfo related, get the value of the property, cast it to an IEnumerable (assuming it's possible) and then iterate through each child and call ReflectObject(...) on the child with the count variable.

  Read the article

• How can I create a WebBrowser control (ActiveX / IWebBrowser2) without a UI?

  - by wangminhere

  I cannot figure out how to use the WebBrowser control without having it create a window in the taskbar. I am using the IWebBrowser2 ActiveX control directly because I need to use some of the advanced features like blocking downloading JAVA/ActiveX/images etc. That apparently is not available in the WPF or winforms WebBrowser wrappers (but these wrappers do have the ability to create the control with no UI) Here is my code for creating the control: Type webbrowsertype = Type.GetTypeFromCLSID(Iid_Clsids.CLSID_WebBrowser, true); m_WBWebBrowser2 = (IWebBrowser2)System.Activator.CreateInstance(webbrowsertype); m_WBWebBrowser2.Visible = false; m_WBOleObject = (IOleObject)m_WBWebBrowser2; int iret = m_WBOleObject.SetClientSite(this); iret = m_WBOleObject.SetHostNames("me", string.Empty); tagRECT rect = new tagRECT(0, 0, 0, 0); tagMSG nullMsg = new tagMSG(); m_WBOleInPlaceObject = (IOleInPlaceObject)m_WBWebBrowser2; //INPLACEACTIVATE the WB iret = m_WBOleObject.DoVerb((int)OLEDOVERB.OLEIVERB_INPLACEACTIVATE, ref nullMsg, this, 0, IntPtr.Zero, ref rect); IConnectionPointContainer cpCont = (IConnectionPointContainer)m_WBWebBrowser2; Guid guid = typeof(DWebBrowserEvents2).GUID; IConnectionPoint m_WBConnectionPoint = null; cpCont.FindConnectionPoint(ref guid, out m_WBConnectionPoint); m_WBConnectionPoint.Advise(this, out m_dwCookie); This code works perfectly but it shows a window in the taskbar. If i omit the DoVerb(OLEDOVERB.OLEIVERB_INPLACEACTIVATE) call, then Navigating to a webpage is not working properly. Navigate() will not download everything on the page and it never fires the DocumentComplete event. If I add a DoVerb(OLEIVERB_HIDE) then I get the same behavior as if I omitted the DoVerb(OLEDOVERB.OLEIVERB_INPLACEACTIVATE) call. This seems like a pretty basic question but I couldn't find any examples anywhere.

  Read the article

• mysql partitioning

  - by Yang

  just want to verify that database partition is implemented only at the database level, when we query a partitioned table, we still do our normal query, nothing special with our queries, the optimization is performed automatically when parsing the query, is that correct? e.g. we have a table called 'address' with a column called 'country_code' and 'city'. so if i want to get all the addresses in New York, US, normally i wound do something like this: select * from address where country_code = 'US' and city = 'New York' if now the table is partitioned by 'country_code', and i know that now the query will only be executed on the partition which contains country_code = US. My question is do I need to explicitly specify the partition to query in my sql statement? or i still use the previous statement and the db server will optimize it automatically? Thanks in advance!

  Read the article

• multiple calender in exchange web service

  - by user3559462

  i have multiple calender in my mailbox, i can retrieve only one calender that is main calnder folder using ews api 2.0, now i want whole list of calenders and appointments and meetings in that. like i have three calender one is main calnder 1.Calender(color-code:default) 2.Jorgen(color-code:pink) 3.Soren(color-code: yellow) i can retrieve all the values of main "Calnder", using the below code Folder inbox = Folder.Bind(service, WellKnownFolderName.Calendar); view.PropertySet = new PropertySet(BasePropertySet.IdOnly); // This results in a FindItem call to EWS. FindItemsResults<Item> results = inbox.FindItems(view); i = 1; m = results.TotalCount; if (results.Count() > 0) { foreach (var item in results) { PropertySet props = new PropertySet(AppointmentSchema.MimeContent,AppointmentSchema.ParentFolderId,AppointmentSchema.Id,AppointmentSchema.Categories,AppointmentSchema.Location); // This results in a GetItem call to EWS. var email = Appointment.Bind(service, item.Id, props); string iCalFileName = @"C:\export\appointment" +i ".ics"; // Save as .eml. using (FileStream fs = new FileStream(iCalFileName, FileMode.Create, FileAccess.Write)) { fs.Write(email.MimeContent.Content, 0, email.MimeContent.Content.Length); } i++; } now i want to get all the remaining calender schedules also, i am not able to get is Please help, need it urgently

  Read the article

• Pass Result of ASIHTTPRequest "requestFinished" Back to Originating Method

  - by Intelekshual

  I have a method (getAllTeams:) that initiates an HTTP request using the ASIHTTPRequest library. NSURL *httpURL = [[[NSURL alloc] initWithString:@"/api/teams" relativeToURL:webServiceURL] autorelease]; ASIHTTPRequest *request = [[[ASIHTTPRequest alloc] initWithURL:httpURL] autorelease]; [request setDelegate:self]; [request startAsynchronous]; What I'd like to be able to do is call [WebService getAllTeams] and have it return the results in an NSArray. At the moment, getAllTeams doesn't return anything because the HTTP response is evaluated in the requestFinished: method. Ideally I'd want to be able to call [WebService getAllTeams], wait for the response, and dump it into an NSArray. I don't want to create properties because this is disposable class (meaning it doesn't store any values, just retrieves values), and multiple methods are going to be using the same requestFinished (all of them returning an array). I've read up a bit on delegates, and NSNotifications, but I'm not sure if either of them are the best approach. I found this snippet about implementing callbacks by passing a selector as a parameter, but it didn't pan out (since requestFinished fires independently). Any suggestions? I'd appreciate even just to be pointed in the right direction. NSArray *teams = [[WebService alloc] getAllTeams]; (currently doesn't work, because getAllTeams doesn't return anything, but requestFinished does. I want to get the result of requestFinished and pass it back to getAllTeams:)

  Read the article

• Open a buffer as a vertical split in VIM

  - by alfredodeza

  If you are editing a file in VIM and then you need to open an existing buffer (e.g. from your buffer list: :buffers) how can you open it in a vertical split? I know that you already can open it with a normal split like: :sbuffer N Wehere N is the buffer number you want, however, the above opens that N buffer horizontally, not vertically. I'm also aware that you can change the window placement after opening and have a Vertical Split like so: Ctrl-W H Ctrl-W L Which will vertically split the window to the right or the left. It seems to me that if there is a sbuffer there should be a vsbuffer but that doesn't exist (not that I am aware of) Also, please note that I am not looking for a plugin to solve this question. I know about a wealth of plugins that will allow you to do this. I am sure I might be missing something that is already there. EDIT: In the best spirit of collaboration, I have created a simple Function with a Mapping if someone else stumbles across this issue and do not want to install a plugin: Function: " Vertical Split Buffer Function function VerticalSplitBuffer(buffer) execute "vert belowright sb" a:buffer endfunction Mapping: " Vertical Split Buffer Mapping command -nargs=1 Vbuffer call VerticalSplitBuffer(<f-args>) This accomplishes the task of opening a buffer in a right split, so for buffer 1, you would call it like: :Vbuffer 1

  Read the article

• C# 4.0: casting dynamic to static

  - by Kevin Won

  This is an offshoot question that's related to another I asked here. I'm splitting it off because it's really a sub-question: I'm having difficulties casting an object of type dynamic to another (known) static type. I have an ironPython script that is doing this: import clr clr.AddReference("System") from System import * def GetBclUri(): return Uri("http://google.com") note that it's simply newing up a BCL System.Uri type and returning it. So I know the static type of the returned object. now over in C# land, I'm newing up the script hosting stuff and calling this getter to return the Uri object: dynamic uri = scriptEngine.GetBclUri(); System.Uri u = uri as System.Uri; // casts the dynamic to static fine Works no problem. I now can use the strongly typed Uri object as if it was originally instantiated statically. however.... Now I want to define my own C# class that will be newed up in dynamic-land just like I did with the Uri. My simple C# class: namespace Entity { public class TestPy // stupid simple test class of my own { public string DoSomething(string something) { return something; } } } Now in Python, new up an object of this type and return it: sys.path.append(r'C:..path here...') clr.AddReferenceToFile("entity.dll") import Entity.TestPy def GetTest(): return Entity.TestPy(); // the C# class then in C# call the getter: dynamic test = scriptEngine.GetTest(); Entity.TestPy t = test as Entity.TestPy; // t==null!!! here, the cast does not work. Note that the 'test' object (dynamic) is valid--I can call the DoSomething()--it just won't cast to the known static type string s = test.DoSomething("asdf"); // dynamic object works fine so I'm perplexed. the BCL type System.Uri will cast from a dynamic type to the correct static one, but my own type won't. There's obviously something I'm not getting about this...

  Read the article

• Thread safe lockfree mutual ByteArray queue

  - by user313421

  A byte stream should be transferred and there is one producer thread and a consumer one. Speed of producer is higher than consumer most of the time, and I need enough buffered data for QoS of my application. I read about my problem and there are solutions like shared buffer, PipeStream .NET class ... This class is going to be instantiated many times on server so I need and optimized solution. Is it good idea to use a Queue of ByteArray ? If yes, I'll use an optimization algorithm to guess the Queue size and each ByteArray capacity and theoretically it fits my case. If no, I what's the best approach ? Please let me know if there's a good lock free thread safe implementation of ByteArray Queue in C# or VB. Thanks in advance

  Read the article

• Invalid argument in sendfile() with two regular files

  - by Daniel Hershcovich

  I'm trying to test the sendfile() system call under Linux 2.6.32 to zero-copy data between two regular files. As far as I understand, it should work: ever since 2.6.22, sendfile() has been implemented using splice(), and both the input file and the output file can be either regular files or sockets. The following is the content of sendfile_test.c: #include <sys/sendfile.h> #include <fcntl.h> #include <stdio.h> int main(int argc, char **argv) { int result; int in_file; int out_file; in_file = open(argv[1], O_RDONLY); out_file = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0644); result = sendfile(out_file, in_file, NULL, 1); if (result == -1) perror("sendfile"); close(in_file); close(out_file); return 0; } And when I'm running the following commands: $ gcc sendfile_test.c $ ./a.out infile The output is sendfile: Bad file descriptor Which means that the system call resulted in errno = -EINVAL, I think. What am I doing wrong?

  Read the article

• Apache CXF REST Services w/ Spring AOP

  - by jconlin

  I'm trying to get Apache CXF JAX-RS services working with Spring AOP. I've created a simple logging class: public class AOPLogger{ public void logBefore(){ System.out.println("Logging Before!"); } } My Spring configuration (beans.xml): <aop:config> <aop:aspect id="aopLogger" ref="test.aop.AOPLogger"> <aop:before method="logBefore" pointcut="execution(* test.rest.RestService(..))"/> </aop:aspect> </aop:config> <bean id="aopLogger" class="test.aop.AOPLogger"/> I always get an NPE in RestService when a call is made to a Method getServletRequest(), which has: return messageContext.getHttpServletRequest(); If I remove the aop configuration or comment it out from my beans.xml, everything works fine. All of my actual Rest services extend test.rest.RestService (which is a class) and call getServletRequest(). I'm just trying to just get AOP up and running based off of the example in the CXF JAX-RS documentation. Does anyone have any idea what I'm doing wrong? Thanks!

  Read the article

• TFS Solution build cascading to several other builds even when common components were not modified

  - by Bob Palmer

  Hey all, here is the issue I am currently trying to work through. We are using Team Foundation Server 2008, and utilizing the automated build support out of the box. We have one very large project that encompasses a number of interrelated components and web sites, each of which is set up as a Visual Studio solution file. Many of these solutions are highly interrelated since they may contain applications, or contain common libraries or shared components. We have roughly 20 or so applications, three large web sites, and about 20 components. Each solution may include projects from other solutions. For example, a solution for a console app would also include the project files for all of the components it utilizes, since we need to ensure that when someone changes a component and rebuilds it, it is reflected in all of the projects that consume that component, and we can make sure nothing was broken. We have build projects for each solution, whether that's an application, component, or web site. For this example, we will call them solutions 01, 02, and 03. These reference multiple projects (both their own core project and test projects, plus the projects relating to various components). Solution 01 has projects A, B, and C. Solution 02 has projects C, D, and E. Solution 03 has projects E, F, and G. Now, for the problem. If I modify project A, the system will end up rebuilding all three solutions. Worse, all thirty solutions reference common projects used for data access (let's call it project H). Because they all share one project in common, if I modify any solution in my stack, even if it does not touch project H, I still end up kicking off every single build script. Any thoughts on how to address this? Ideally I would only want to kick off builds where their constituant projects were directly modified - i.e in the example below, if I modified project C, I would only rebuild solutions 01 and 02. Thanks!

  Read the article

• Can a destructor be recursive?

  - by Cubbi

  Is this program well-defined, and if not, why exactly? #include <iostream> #include <new> struct X { int cnt; X (int i) : cnt(i) {} ~X() { std::cout << "destructor called, cnt=" << cnt << std::endl; if ( cnt-- > 0 ) this->X::~X(); // explicit recursive call to dtor } }; int main() { char* buf = new char[sizeof(X)]; X* p = new(buf) X(7); p->X::~X(); // explicit call to dtor delete[] buf; } My reasoning: although invoking a destructor twice is undefined behavior, per 12.4/14, what it says exactly is this: the behavior is undefined if the destructor is invoked for an object whose lifetime has ended Which does not seem to prohibit recursive calls. While the destructor for an object is executing, the object's lifetime has not yet ended, thus it's not UB to invoke the destructor again. On the other hand, 12.4/6 says: After executing the body [...] a destructor for class X calls the destructors for X's direct members, the destructors for X's direct base classes [...] which means that after the return from a recursive invocation of a destructor, all member and base class destructors will have been called, and calling them again when returning to the previous level of recursion would be UB. Therefore, a class with no base and only POD members can have a recursive destructor without UB. Am I right?

  Read the article

• Save a form in an XML file using Ajax and JSP

  - by novellino

  Hello, I want to create a simple form with a name and an email and save these data in an XML file. So far I found that using Ajax with jQuery is quite easy. So I used the usual code: //dataString have the values taken from the form var dataString = 'name='+ name + '&email=' + email; $.ajax({ type: "POST", url: "users.xml", data: dataString, dataType: "xml", success: function() { .... } }); If I understood well, in the url I should add the name of the XML file that will be created. When the user clicks a button I call the function with the Ajax request, and then I should call somewhere a function for generating the xml. I am using also two beans. One is for setting the elements of the user and the other is for saving the data in the XML. I am using the XStream library for the xml although I don't know if is the best solution. The problem now it that I can not connect all these together in order to save the data in the XML. Does anyone know what should I do? Thanks a lot!

  Read the article

• removing duplicate strings from a massive array in java efficiently?

  - by Preator Darmatheon

  I'm considering the best possible way to remove duplicates from an (Unsorted) array of strings - the array contains millions or tens of millions of stringz..The array is already prepopulated so the optimization goal is only on removing dups and not preventing dups from initially populating!! I was thinking along the lines of doing a sort and then binary search to get a log(n) search instead of n (linear) search. This would give me nlogn + n searches which althout is better than an unsorted (n^2) search = but this still seems slow. (Was also considering along the lines of hashing but not sure about the throughput) Please help! Looking for an efficient solution that addresses both speed and memory since there are millions of strings involved without using Collections API!

  Read the article

< Previous Page | 395 396 397 398 399 400 401 402 403 404 405 406  | Next Page >