Search Results

Search found 42453 results on 1699 pages for 'my question'.

Page 74/1699 | < Previous Page | 70 71 72 73 74 75 76 77 78 79 80 81  | Next Page >

  • linux raw socket programming question

    - by user194420
    Hi all, I am trying to create a raw socket which send and receive message with ip/tcp header under linux. I can successfully binds to a port and receive tcp message(ie:syn) However, the message seems to be handled by the os, but not mine. I am just a reader of it(like wireshark). My raw socket binds to port 8888, and then i try to telnet to that port . In wireshark, it shows that the port 8888 reply a "rst ack" when it receive the "syn" request. In my program, it shows that it receive a new message and it doesnot reply with any message. Any way to actually binds to that port?(prevent os handle it) Here is part of my code, i try to cut those error checking for easy reading sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_TCP); int tmp = 1; const int *val = &tmp; setsockopt (sockfd, IPPROTO_IP, IP_HDRINCL, val, sizeof (tmp)); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = htonl(INADDR_ANY); servaddr.sin_port = htons(8888); bind(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr)); //call recv in loop

    Read the article

  • JPA Inheritance and Relations - Clarification question

    - by Michael
    Here the scenario: I have a unidirectional 1:N Relation from Person Entity to Address Entity. And a bidirectional 1:N Relation from User Entity to Vehicle Entity. Here is the Address class: @Entity public class Address implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) privat Long int ... The Vehicles Class: @Entity public class Vehicle implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne private User owner; ... @PreRemove protected void preRemove() { //this.owner.removeVehicle(this); } public Vehicle(User owner) { this.owner = owner; ... The Person Class: @Entity @Inheritance(strategy = InheritanceType.JOINED) @DiscriminatorColumn(name="PERSON_TYP") public class Person implements Serializable { @Id protected String username; @OneToMany(cascade = CascadeType.ALL, orphanRemoval=true) @JoinTable(name = "USER_ADDRESS", joinColumns = @JoinColumn(name = "USERNAME"), inverseJoinColumns = @JoinColumn(name = "ADDRESS_ID")) protected List<Address> addresses; ... @PreRemove protected void prePersonRemove(){ this.addresses = null; } ... The User Class which is inherited from the Person class: @Entity @Table(name = "Users") @DiscriminatorValue("USER") public class User extends Person { @OneToMany(mappedBy = "owner", cascade = {CascadeType.PERSIST, CascadeType.REMOVE}) private List<Vehicle> vehicles; ... When I try to delete a User who has an address I have to use orphanremoval=true on the corresponding relation (see above) and the preRemove function where the address List is set to null. Otherwise (no orphanremoval and adress list not set to null) a foreign key contraint fails. When i try to delete a user who has an vehicle a concurrent Acces Exception is thrown when do not uncomment the "this.owner.removeVehicle(this);" in the preRemove Function of the vehicle. The thing i do not understand is that before i used this inheritance there was only a User class which had all relations: @Entity @Table(name = "Users") public class User implements Serializable { @Id protected String username; @OneToMany(mappedBy = "owner", cascade = {CascadeType.PERSIST, CascadeType.REMOVE}) private List<Vehicle> vehicles; @OneToMany(cascade = CascadeType.ALL) @JoinTable(name = "USER_ADDRESS", joinColumns = @JoinColumn(name = "USERNAME") inverseJoinColumns = @JoinColumn(name = "ADDRESS_ID")) ptivate List<Address> addresses; ... No orphanremoval, and the vehicle class has used the uncommented statement above in its preRemove function. And - I could delte a user who has an address and i could delte a user who has a vehicle. So why doesn't everything work without changes when i use inheritance? I use JPA 2.0, EclipseLink 2.0.2, MySQL 5.1.x and Netbeans 6.8

    Read the article

  • Axis Rotation Question

    - by Leo
    By using left hand rule, I rotate one object left and right using y axis, and rotate up/down using x axis. After first object is rotated to the right, the up/down rotation should be using z axis. However, when I try to rotate using z axis, after the first rotation, it has the same effect when I rotate using y axis. Anyone has any ideas? Thanks

    Read the article

  • question about qsort in c++

    - by davit-datuashvili
    i have following code in c++ #include <iostream> using namespace std; void qsort5(int a[],int n){ int i; int j; if (n<=1) return; for (i=1;i<n;i++) j=0; if (a[i]<a[0]) swap(++j,i,a); swap(0,j,a); qsort5(a,j); qsort(a+j+1,n-j-1); } int main() { return 0; } void swap(int i,int j,int a[]) { int t=a[i]; a[i]=a[j]; a[j]=t; } i have problem 1>c:\users\dato\documents\visual studio 2008\projects\qsort5\qsort5\qsort5.cpp(13) : error C2780: 'void std::swap(std::basic_string<_Elem,_Traits,_Alloc> &,std::basic_string<_Elem,_Traits,_Alloc> &)' : expects 2 arguments - 3 provided 1> c:\program files\microsoft visual studio 9.0\vc\include\xstring(2203) : see declaration of 'std::swap' 1>c:\users\dato\documents\visual studio 2008\projects\qsort5\qsort5\qsort5.cpp(13) : error C2780: 'void std::swap(std::pair<_Ty1,_Ty2> &,std::pair<_Ty1,_Ty2> &)' : expects 2 arguments - 3 provided 1> c:\program files\microsoft visual studio 9.0\vc\include\utility(76) : see declaration of 'std::swap' 1>c:\users\dato\documents\visual studio 2008\projects\qsort5\qsort5\qsort5.cpp(13) : error C2780: 'void std::swap(_Ty &,_Ty &)' : expects 2 arguments - 3 provided 1> c:\program files\microsoft visual studio 9.0\vc\include\utility(16) : see declaration of 'std::swap' 1>c:\users\dato\documents\visual studio 2008\projects\qsort5\qsort5\qsort5.cpp(14) : error C2780: 'void std::swap(std::basic_string<_Elem,_Traits,_Alloc> &,std::basic_string<_Elem,_Traits,_Alloc> &)' : expects 2 arguments - 3 provided 1> c:\program files\microsoft visual studio 9.0\vc\include\xstring(2203) : see declaration of 'std::swap' 1>c:\users\dato\documents\visual studio 2008\projects\qsort5\qsort5\qsort5.cpp(14) : error C2780: 'void std::swap(std::pair<_Ty1,_Ty2> &,std::pair<_Ty1,_Ty2> &)' : expects 2 arguments - 3 provided 1> c:\program files\microsoft visual studio 9.0\vc\include\utility(76) : see declaration of 'std::swap' 1>c:\users\dato\documents\visual studio 2008\projects\qsort5\qsort5\qsort5.cpp(14) : error C2780: 'void std::swap(_Ty &,_Ty &)' : expects 2 arguments - 3 provided 1> c:\program files\microsoft visual studio 9.0\vc\include\utility(16) : see declaration of 'std::swap' 1>c:\users\dato\documents\visual studio 2008\projects\qsort5\qsort5\qsort5.cpp(16) : error C2661: 'qsort' : no overloaded function takes 2 arguments 1>Build log was saved at "file://c:\Users\dato\Documents\Visual Studio 2008\Projects\qsort5\qsort5\Debug\BuildLog.htm" please help

    Read the article

  • magento - webserver question

    - by WANNABE
    I've uploaded the Magento installation file to my hosting and I've been told to go to the URL you uploaded it to using you browser, then the installation wizard will run you through the processes. I uploaded to /home/domain/public_html/magneto What URL should I use to access it? Thanks in advance

    Read the article

  • setBit java method using bit shifting and hexadecimal code - question

    - by somewhat_confused
    I am having trouble understanding what is happening in the two lines with the 0xFF7F and the one below it. There is a link here that explains it to some degree. http://www.herongyang.com/java/Bit-String-Set-Bit-to-Byte-Array.html I don't know if 0xFF7FposBit) & oldByte) & 0x00FF are supposed to be 3 values 'AND'ed together or how this is supposed to be read. If anyone can clarify what is happening here a little better, I would greatly appreciate it. private static void setBit(byte[] data, final int pos, final int val) { int posByte = pos/8; int posBit = pos%8; byte oldByte = data[posByte]; oldByte = (byte) (((0xFF7F>>posBit) & oldByte) & 0x00FF); byte newByte = (byte) ((val<<(8-(posBit+1))) | oldByte); data[posByte] = newByte; } passed into this method as parameters from a selectBits method was setBit(out,i,val); out = is byte[] out = new byte[numOfBytes]; (numOfBytes can be 7 in this situation) i = which is number [57], the original number from the PC1 int array holding the 56-integers. val = which is the bit taken from the byte array from the getBit() method.

    Read the article

  • MySQL easy question CURDATE()

    - by Tristan
    I want to compare two results one is stored in the first query, and the other is exactly the same as the first, but i want only to recieve data < today "SELECT s.GSP_nom as nom, timestamp, COUNT(s.GSP_nom) as nb_votes, AVG(v.vote+v.prix+v.serviceClient+v.interface+v.interface+v.services)/6 as moy FROM votes_serveur AS v INNER JOIN serveur AS s ON v.idServ = s.idServ WHERE s.valide = 1 AND v.date < CURDATE() ROUP BY s.GSP_nom HAVING nb_votes > 9 ORDER BY moy DESC LIMIT 0,15"; is that correct ? thank you

    Read the article

  • MUD (game) design concept question about timed events.

    - by mudder
    I'm trying my hand at building a MUD (multiplayer interactive-fiction game) I'm in the design/conceptualizing phase and I've run into a problem that I can't come up with a solution for. I'm hoping some more experienced programmers will have some advice. Here's the problem as best I can explain it. When the player decides to perform an action he sends a command to the server. the server then processes the command, determines whether or not the action can be performed, and either does it or responds with a reason as to why it could not be done. One reason that an action might fail is that the player is busy doing something else. For instance, if a player is mid-fight and has just swung a massive broadsword, it might take 3 seconds before he can repeat this action. If the player attempts to swing again to soon, the game will respond indicating that he must wait x seconds before doing that. Now, this I can probably design without much trouble. The problem I'm having is how I can replicate this behavior from AI creatures. All of the events that are being performed by the server ON ITS OWN, aka not as an immediate reaction to something a player has done, will have to be time sensitive. Some evil monster has cast a spell on you but must wait 30 seconds before doing it again... I think I'll probably be adding all these events to some kind of event queue, but how can I make that event queue time sensitive?

    Read the article

  • iPhone SDK Question with Audio/Mic

    - by Henry D'Andrea
    I am trying to do an app, to where when it launches, it will detect audio, and then play it back automatically. NO BUTTONS, nothing to press. Just a picture of something then, it listens for audio, then plays it back. Similar to the Talking Carl app in the App Store. Any ideas/help? Would appreciate it, if i could use the code with IB.

    Read the article

  • General ORM design question

    - by Calvin
    Suppose you have 2 classes, Person and Rabbit. A person can do a number of things to a rabbit, s/he can either feed it, buy it and become its owner, or give it away. A rabbit can have none or at most 1 owner at a time. And if it is not fed for a while, it may die. Class Person { Void Feed(Rabbit r); Void Buy(Rabbit r); Void Giveaway(Person p, Rabbit r); Rabbit[] rabbits; } Class Rabbit { Bool IsAlive(); Person pwner; } There are a couple of observations from the domain model: Person and Rabbit can have references to each other Any actions on 1 object can also change the state of the other object Even if no explicit actions are invoked, there can still be a change of state in the objects (e.g. Rabbit can be starved to death, and that causes it to be removed from the Person.rabbits array) As DDD is concerned, I think the correct approach is to synchronize all calls that may change the states in the domain model. For instance, if a Person buys a Rabbit, s/he would need to acquire a lock in Person to make a change to the rabbits array AND also another lock in Rabbit to change its owner before releasing the first one. This would prevent a race condition where 2 Persons claim to be the owner of the little Rabbit. The other approach is to let the database to handle all these synchronizations. Who makes the first call wins, but then the DB needs to have some kind of business logics to figure out if it is a valid transaction (e.g. if a Rabbit already has an owner, it cannot change its owner unless the Person gives it away). There are both pros/cons in either approach, and I’d expect the “best” solution would be somewhere in-between. How would you do it in real life? What’s your take and experience? Also, is it a valid concern that there can be another race condition the domain model has committed its change but before it is fully committed in the database? And for the 3rd observation (i.e. state change due to time factor). How will you do it?

    Read the article

  • Question of using static_cast on "this" pointer in a derived object to base class

    - by Johnyy
    Hi, this is an example taken from Effective C++ 3ed, it says that if the static_cast is used this way, the base part of the object is copied, and the call is invoked from that part. I wanted to understand what is happening under the hood, will anyone help? class Window { // base class public: virtual void onResize() { } // base onResize impl }; class SpecialWindow: public Window { // derived class public: virtual void onResize() { // derived onResize impl; static_cast<Window>(*this).onResize(); // cast *this to Window, // then call its onResize; // this doesn't work! // do SpecialWindow- } // specific stuff };

    Read the article

  • Question about oracle db connection with .NET

    - by john
    I'm trying to connect to an oracle database with .net but i get the error: ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified however, when I enter add a new database connection through toolsconnect to database. it works fine. even after copying the connection string which is: Data Source=source here;Persist Security Info=True;User ID=userhere;Password=pass;Unicode=True

    Read the article

  • rotating circle with swipe question

    - by Joe
    Okay so I'm making something that basically works as a knob, but only half on the screen -- so I just need horizontal swipes to cause it to rotate. I have it nearly all sorted with one exception: if you change direction of your swipe in mid-swipe, the rotation doesn't change direction. I even can see the problem, but not sure what to do about a solution. So in my touchesMoved, I get the swipe into radians in the predictable way: CGFloat radians = atan2f(location.y - centerY, location.x - centerX); I then store radians, add/subtract it to previous rotation and then give the result to the CATransform3D. So the prob is that even though the swipe changes direction, there is a "balance" which doesn't allow an immediate change of direction. Does this make any sense?

    Read the article

  • StructureMap Question

    - by derans
    This is the equivalent of what I'm trying to create with StructureMap: new ChangePasswordWithNotificationAndLoggingService( new ChangePasswordService( new ActiveDirectoryRepository(new ActiveDirectoryCredentials()), new TokenRepository("")), new EmailNotificationService(new PasswordChangedNotification(new UserAccount())), new LoggingService()); This is what I have right now: ForRequestedType<IChangePasswordService>() .TheDefault.Is.ConstructedBy(() => new ChangePasswordService(DependencyRegistrar.Resolve<IActiveDirectoryRepository>(), DependencyRegistrar.Resolve<ITokenRepository>())) .EnrichWith<IChangePasswordService>(x => new ChangePasswordWithNotificationAndLoggingService(x, DependencyRegistrar.Resolve<INotificationService>(), DependencyRegistrar.Resolve<ILoggingService>())); I need to pass the UserAccount to the INotificationService...can't figure it out. I've tried this: DependencyRegistrar.With(new UserAccount { Username = "test" }); No luck...UserAccount always turns out null. I don't have to do it all with StructureMap, I'm open to any suggestions. This is what I currently have working: public static IChangePasswordService ChangePasswordService(UserAccount userAccount) { return new ChangePasswordWithNotificationService( new ChangePasswordService(ActiveDirectoryRepository(), TokenRepository()), new EmailNotificationService(new PasswordChangedNotification(userAccount))); }

    Read the article

  • Python decorator question

    - by nsharish
    decorator 1: def dec(f): def wrap(obj, *args, **kwargs): f(obj, *args,**kwargs) return wrap decorator 2: class dec: def __init__(self, f): self.f = f def __call__(self, obj, *args, **kwargs): self.f(obj, *args, **kwargs) A sample class, class Test: @dec def disp(self, *args, **kwargs): print(*args,**kwargs) The follwing code works with decorator 1 but not with decorator 2. a = Test() a.disp("Message") I dont understand why decorator 2 is not working here. Can someone help me with this?

    Read the article

  • Flex 4 app with mate design question

    - by chchrist
    Hi all, I have a view with a DropDownList component and a DataGroup component. The dropdownlist has to be updated from a remote php object and on change to call another remote object service in order to update the datagroup's provider. So I am thinks to dispatch an event from my view and the in my EventMap to call the service and inject the result to the drop down. When the dropdown changes I'll dispatch another event and in the EventMap I'll call another service and I'll inject the result to the datagroup. Is there another more sophisticated way? Thanks in advance

    Read the article

  • Singleton constructor question

    - by gillyb
    Hi, I created a Singleton class in c#, with a public property that I want to initialize when the Singleton is first called. This is the code I wrote : public class BL { private ISessionFactory _sessionFactory; public ISessionFactory SessionFactory { get { return _sessionFactory; } set { _sessionFactory = value; } } private BL() { SessionFactory = Dal.SessionFactory.CreateSessionFactory(); } private object thisLock = new object(); private BL _instance = null; public BL Instance { get { lock (thisLock) { if (_instance == null) { _instance = new BL(); } return _instance; } } } } As far as I know, when I address the Instance BL object in the BL class for the first time, it should load the constructor and that should initialize the SessionFactory object. But when I try : BL.Instance.SessionFactory.OpenSession(); I get a Null Reference Exception, and I see that SessionFactory is null... why?

    Read the article

  • Multiple memcached servers question.

    - by Andre
    hypothetically - if I have multiple memcached servers like this: //PHP $MEMCACHE_SERVERS = array( "10.1.1.1", //web1 "10.1.1.2", //web2 "10.1.1.3", //web3 ); $memcache = new Memcache(); foreach($MEMCACHE_SERVERS as $server){ $memcache->addServer ( $server ); } And then I set data like this: $huge_data_for_frong_page = 'some data blah blah blah'; $memcache->set("huge_data_for_frong_page", $huge_data_for_frong_page); And then I retrieve data like this: $huge_data_for_frong_page = $memcache->get("huge_data_for_frong_page"); When i would to retrieve this data from memcached servers - how would php memcached client know which server to query for this data? Or is memcached client going to query all memcached servers?

    Read the article

  • MongoDB: embedding performance question

    - by Alex
    I just started learning MongoDB, and I really like the idea of embedding collections instead of referencing them. MongoDB's documentation recommends to use embedding if performance is needed. I just thought about a simple forum model. Let's say, every board category has several boards, every board has several topics, and every topic has several messages. All of these collections are embedded. After some time the size of the board category will be huge. Way more than the 2MB limit. Does this mean that there's a flaw in this design?

    Read the article

  • Regular Expression Question

    - by zyq524
    I'm trying to use regular expression to extract the comments in the heading of a file. For example, the source code may look like: //This is an example file. //Please help me. #include "test.h" int main() //main function { ... } What I want to extract from the code are the first two lines, i.e. //This is an example file. //Please help me. Any idea?

    Read the article

  • Getting Preferred, Varied Products -- Tough Pseudocode Question

    - by Volomike
    I have a Dallas client who has given me a tough process to work out. I'm seeking your advice. I use PHP, but the language doesn't matter. We can work this out in pseudocode. In a nutshell, this involves showing products on a page based on matching keyword phrases, and using a preferred product provider, but varying this up so that I try to show products from each provider as much as possible when I can. He has 3 product companies: Amazon, eBay, and Overstock. I already have worked out with the API to get products back in an array via a function. He wants to give the user the preference of which one to use primarily -- so a priority number on each. He wants to display anywhere from 1 to 6 products on a page from them. Let's go with 6 for now in this example to start with. Let's assume Amazon first, then eBay, then Overstock as far as priority. He wants me to attempt to take a keyword phrase and find relevant products (all the keywords found in product title) from Amazon, eBay, and Overstock. If we find 1 product from each provider, he wants me to only display one product from each. But if we run out of a particular provider with a matching product, I start over again and grab another product from another provider until we reach 6 products. If there just aren't 6 relevant products, then I do the best I can -- even if I only display one product. If no relevant products, then I don't display anything.

    Read the article

  • I have a question about URI templates in WCF Services

    - by Debby
    I have a web service with following operation contract and my service is hosted at http://localhost:9002/Service.svc/ [OperationContract] [WebGet(UriTemplate = "/Files/{Filepath}")] Stream DownloadFile(string Filepath); This web service would let users download file, if the proper filepath is provided (assuming, I somehow find out that proper filepath). Now, I can access this service from a browser by typing, http://localhost:9002/Service.svc/Files/(Filepath} If {filepath} is some simple string, its not a problem, but I want to send the location of the file. Lets us say users want to download file C:\Test.mp3 on the server. But how can I pass C:\Test.mp3 as {Filepath}? I get an error when I type http://localhost:9002/Service.svc/Files/C:\Test.mp3 in the browser. I am new to web services and find that this community is the quickest way to get answers to my questions.

    Read the article

< Previous Page | 70 71 72 73 74 75 76 77 78 79 80 81  | Next Page >