Search Results

Search found 36506 results on 1461 pages for 'unsigned long long int'.

Page 341/1461 | < Previous Page | 337 338 339 340 341 342 343 344 345 346 347 348  | Next Page >

  • How can CopyOnWriteArrayList be thread-safe?

    - by Shooshpanchick
    I've taken a look into OpenJDK's sources of CopyOnWriteArrayList and it seems that all write operations are protected by the same lock and read operations are not protected at all. As I understand, under JMM all accesses to a variable (both read and write) should be protected by lock or reordering effects may occur. For example, set(int, E) method contains these lines (under lock): /* 1 */ int len = elements.length; /* 2 */ Object[] newElements = Arrays.copyOf(elements, len); /* 3 */ newElements[index] = element; /* 4 */ setArray(newElements); The get(int) method, on the other hand, only does return get(getArray(), index);. In my understanding of JMM, this means that get may observe the array in an inconsistent state if statements 1-4 are reordered like 1-2(new)-4-2(copyOf)-3. Do I understand JMM incorrectly or is there any other explanations on why CopyOnWriteArrayList is thread-safe?

    Read the article

  • In C, is it possible do free only an array first or last position?

    - by user354959
    Hi there! I've an array, but I don't need its first (or last) position. So I point a new variable to the rest of the array, but I should free the array first/last position. For instance: p = read_csv_file(); q = p + 1; // I don't need the first CSV file field // Here I'd like to free only the first position of p return q; Otherwise I've to memcpy the array to other variable, excluding the first position, and then free the original array. Like this: p = read_csv_file(); q = (int*) malloc(sizeof(int) * (SOME_SIZE - 1)); memcpy(q, p+1, sizeof(int) * (SOME_SIZE - 1)); free(p); return q; But then I'll have the overhead of copying all the array. Is this possible to only free a single position of an array?

    Read the article

  • why optimization does not happen?

    - by aaa
    hi. I have C/C++ code, that looks like this: static int function(double *I) { int n = 0; // more instructions, loops, for (int i; ...; ++i) n += fabs(I[i] > tolerance); return n; } function(I); // return value is not used. compiler inlines function, however it does not optimize out n manipulations. I would expect compiler is able to recognize that value is never used as rhs only. Is there some side effect, which prevents optimization? Thanks

    Read the article

  • Any chances to imitate times() Ruby method in C#?

    - by Alexander Prokofyev
    Every time I need to do something N times inside an algorithm using C# I write this code for (int i = 0; i < N; i++) { ... } Studying Ruby I have learned about method times() which can be used with the same semantics like this N.times do ... end Code fragment in C# looks more complex and we should declare useless variable i. I tried to write extension method which returns IEnumerable, but I am not satisfied with the result because again I have to declare a cycle variable i. public static class IntExtender { public static IEnumerable Times(this int times) { for (int i = 0; i < times; i++) yield return true; } } ... foreach (var i in 5.Times()) { ... } Is it possible using some new C# 3.0 language features to make N times cycle more elegant?

    Read the article

  • How do you resolve the common collsision between type name and object name?

    - by Catskul
    Since the convention is to capitalize the first letter of public properties, the old c++ convention of initial capital for type names, and initial lowercase for non-type names does not prevent the classic name collision class FooManager { public BarManager BarManager { get; set; } // Feels very wrong. // Recommended naming convention? public int DoIt() { return Foo.Blarb + Foo.StaticBlarb; // 1st and 2nd Foo are two // different symbols } } class BarManager { public int Blarb { get; set; } public static int StaticBlarb { get; set; } } It seems to compile, but feels so wrong. Is there a recommend naming convention to avoid this?

    Read the article

  • Why is forwarding variadic parameters invalid?

    - by awesomeyi
    Consider the variadic function parameter: func foo(bar:Int...) -> () { } Here foo can accept multiple arguments, eg foo(5,4). I am curious about the type of Int... and its supported operations. For example, why is this invalid? func foo2(bar2:Int...) -> () { foo(bar2); } Gives a error: Could not find an overload for '_conversion' that accepts the supplied arguments Why is forwarding variadic parameters invalid? What is the "conversion" the compiler is complaining about?

    Read the article

  • C# & C++, runtime error when call C++ dll from C#

    - by 5YrsLaterDBA
    I have written a C++ wrapper DLL for C# to call. The DLL was tested and worked fine with my C++ test program. now integrated with C#, I got runtime error and crashed. Cannot use debugger to see more details. The C++ side has only one method: #ifdef DLLWRAPPERWIN32_EXPORTS #define DLLWRAPPERWIN32_API __declspec(dllexport) #else #define DLLWRAPPERWIN32_API __declspec(dllimport) #endif #include "NB_DPSM.h" extern "C" { DLLWRAPPERWIN32_API int WriteGenbenchDataWrapper(string fileNameToAnalyze, string parameterFileName, string baseNameToSaveData, string logFileName, string& message) ; } in the C# side, there is a definition, [DllImport("..\\..\\thirdParty\\cogs\\DLLWrapperWin32.dll")] public static extern int WriteGenbenchDataWrapper(string fileNameToAnalyze, string parameterFileName, string baseNameToSaveData, string logFileName, ref string message); and a call: string msg = ""; int returnVal = WriteGenbenchDataWrapper(rawDataFileName, parameterFileName, outputBaseName, logFileName, ref msg); I guess there must be something wrong with the last parameter of the function. string& in C++ should be ref string in C#?

    Read the article

  • initialization of objects in c++

    - by Happy Mittal
    I want to know, in c++, when does the initialization of objects take place? Is it at the compile time or link time? For ex: //file1.cpp extern int i; int j=5; //file2.cpp ( link with file1.cpp) extern j; int i=10; Now, what does compiler do : according to me, it allocates storage for variables. Now I want to know : does it also put initialization value in that storage or is it done at link time?

    Read the article

  • why does the array doesn't get initialized by global variable , even though it should not?

    - by ashish yadav
    why does the array a does not get initialized by global variable 'size'. include int size=5; int main() { int a[size]={1,2,3,4,5}; printf("%d",a[0]); return 0; } the compilation error is shown as "variable-sized object may not be initialized". according to me the array should get initialized by 'size'. i apologize if i am not clear but i feel i have expressed myself well enough. thank you!!!!!!!!!!!

    Read the article

  • Why Is It That Generics Constraint Can't Be Casted to Its Derived Type?

    - by Ngu Soon Hui
    It is quite puzzling to find out that Generics Constraint Can't Be Casted to Its Derived Type. Let's say I have the following code: public abstract class BaseClass { public int Version { get { return 1; } } public string FixString { get; set; } public BaseClass() { FixString = "hello"; } public virtual int GetBaseVersion() { return Version; } } public class DeriveClass: BaseClass { public new int Version { get { return 2; } } } And guess what, this method will return a compilation error: public void FreeConversion<T>(T baseClass) { var derivedMe = (DeriveClass)baseClass; } I would have to cast the baseClass to object first before I can cast it to DerivedClass. Seems to me pretty ugly. Why this is so?

    Read the article

  • "input cannot be resolved" when added a try..catch

    - by Mark
    I originally tried to get my throw statement to work without a try catch and the userInput = input.nextInt(); line worked fine. But when I tried adding the try..catch it didn't like my input saying it cannot be resolved. I don't think my try..catch is correct yet but I am planning on tackling that after I can get this input to be recognized but I would appreciate any feedback on things you see with that as well. Thanks import java.util.Scanner; public class Program6 { public static void main(String[] args) { final int NUMBER_HIGH_LIMIT = 100; final int NUMBER_LOW_LIMIT = 10; int userInput; try { System.out.print("Enter a number between 10 and 100: "); userInput = input.nextInt();//Says input cannot be resolved Verify v = new Verify(NUMBER_HIGH_LIMIT, NUMBER_LOW_LIMIT); } catch(NumberHighException exception) { userInput = 0; } catch(NumberLowException exception) { userInput = 0; } } }

    Read the article

  • Are there any C# collections where modification does not invalidate iterators?

    - by young-phillip
    Are there any data structures in the C# Collections library where modification of the structure does not invalidate iterators? Consider the following: List<int> myList = new List<int>(); myList.Add( 1 ); myList.Add( 2 ); List<int>.Enumerator myIter = myList.GetEnumerator(); myIter.MoveNext(); // myIter.Current == 1 myList.Add( 3 ); myIter.MoveNext(); // throws InvalidOperationException

    Read the article

  • help implementing All Nearest Smaller Values algorithm

    - by davit-datuashvili
    http://en.wikipedia.org/wiki/All_nearest_smaller_values this is site of the problem and here is my code but i have some trouble to implement it import java.util.*; public class stack{ public static void main(String[]args){ int x[]=new int[]{ 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 }; Stack<Integer> st=new Stack<Integer>(); for (int a:x){ while (!st.empty() && st.pop()>=a){ System.out.println( st.pop()); if (st.empty()){ break; } else{ st.push(a); } } } } } and here is pseudo code from site S = new empty stack data structure for x in the input sequence: while S is nonempty and the top element of S is greater than or equal to x: pop S if S is empty: x has no preceding smaller value else: the nearest smaller value to x is the top element of S push x onto S

    Read the article

  • why this signal handler is called infinitely

    - by lz_prgmr
    I am using Mac OS 10.6.5, g++ 4.2.1. And meet problem with following code: #include <iostream> #include <sys/signal.h> using namespace std; void segfault_handler(int signum) { cout << "segfault caught!!!\n"; } int main() { signal(SIGSEGV, segfault_handler); int* p = 0; *p = 100; return 1; } It seems the segfault_handler is called infinitely and keep on print: segfault caught!!! segfault caught!!! segfault caught!!! ... I am new to Mac development, do you have any idea on what happened?

    Read the article

  • WPF TextBox value doesn't change on OnPropertyChanged

    - by jpsstavares
    I have a TextBox whose Value is binded to a ViewModel property: <TextBox Name="txtRunAfter" Grid.Column="4" Text="{Binding Mode=TwoWay, Path=RunAfter}" Style="{StaticResource TestStepTextBox}"/> The set and get were working fine until I tried to add some validation when the Value is set: private int _runAfter = 0; public string RunAfter { get { return _runAfter.ToString(); } set { int val = int.Parse(value); if (_runAfter != val) { if (val < _order) _runAfter = val; else { _runAfter = 0; OnPropertyChanged("RunAfter"); } } } } Although the OnPropertyChanged is reached (I have dubugged that), the View is not changed. How can I make this work? Thanks, José Tavares

    Read the article

  • C++ -- return x,y; The point?

    - by Earlz
    Hello, I have been programming in C and C++ for a few years and now I'm taking a college course in it and our book had a function like this int foo(){ int x=0; int y=20; return x,y; //y is always returned } I have never seen such syntax. In fact, I never see the , operator used outside of parameter lists. If y is always returned though, then what is the point? Is there a case where a return statement would need to be created like this? (Also, I tagged C as well because it applies to both, though my book specifically is C++)

    Read the article

  • AlertDialog not showing two buttons.

    - by jfalexvijay
    Hi AlertDialog not showing send button. Below is the code. Please tell me what mistake I have made in my code. protected Dialog onCreateDialog(int id) { final AlertDialog.Builder dialog = new AlertDialog.Builder(this); dialog.setMessage("Enter Holla message"); EditText hollaMessage = new EditText(this); dialog.setView(hollaMessage); dialog.setCancelable(false); dialog.setPositiveButton("Send", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { List result = new ArrayList(); } }); dialog.setPositiveButton("Cancel", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { dismissDialog(0); } }); AlertDialog alert = dialog.create(); return alert; }

    Read the article

  • Writing to pointer out of bounds after malloc() not causing error

    - by marr
    Hi, when I try the code below it works fine. Am I missing something? main() { int *p; p=malloc(sizeof(int)); printf("size of p=%d\n",sizeof(p)); p[500]=999999; printf("p[0]=%d",p[500]); return 0; } I tried it with malloc(0*sizeof(int)) or anything but it works just fine. The program only crashes when I don't use malloc at all. So even if I allocate 0 memory for the array p, it still stores values properly. So why am I even bothering with malloc then?

    Read the article

  • Why isn't the copy constructor elided here?

    - by Jesse Beder
    (I'm using gcc with -O2.) This seems like a straightforward opportunity to elide the copy constructor, since there are no side-effects to accessing the value of a field in a bar's copy of a foo; but the copy constructor is called, since I get the output meep meep!. #include <iostream> struct foo { foo(): a(5) { } foo(const foo& f): a(f.a) { std::cout << "meep meep!\n"; } int a; }; struct bar { foo F() const { return f; } foo f; }; int main() { bar b; int a = b.F().a; return 0; }

    Read the article

  • strstr whole string match

    - by clay
    I'm trying to match the whole string and not just part of it. For instance, if the needle is 2, I would like to match just the string 2 and not 20, 02, or 22 or anything related. I'm using strstr as: #include <stdio.h> #include <string.h> int main(int argc, char *argv[]) { FILE *file; char l[BUFSIZ]; int linenumber = 1; char term[6] = "2"; file = fopen(argv[1], "r"); if(file != NULL) { while(fgets(l, sizeof(l), file)){ if(strstr(l, term) != NULL) { printf("Search Term Found at %d!\n", linenumber); } ++linenumber; } } else { perror(argv[1]); } fclose(file); return 0; }

    Read the article

  • generating function arguments in java

    - by aloishis89
    I'm very new to java and am working on my first Android app. I am using the webview demo as a template. I am trying to generate a random integer between 1 and 12 and then call a certain javascript function based on the result. Here's what I have: int number = 1 + (int)(Math.random() * ((12 - 1) + 1)); number = (int) Math.floor(number); String nextQuote = "javascript:wave" + number + "()"; mWebView.loadUrl(nextQuote); So mWebView.loadUrl(nextQuote) will be the same as something like mWebView.loadUrl("javascript:wave1()") I just want to know if what I have here is correct and will work the way I think it will. The application isn't responding as expected and I suspect this bit of code is the culprit.

    Read the article

  • Initialization of array on heap

    - by Radek Šimko
    How do i manually initiate values in array on heap? If the array is local variable (in stack), it can be done very elegant and easy way, like this: int myArray[3] = {1,2,3}; Unfortunately, following code int * myArray = new int[3]; myArray = {1,2,3}; outputs an error by compiling error: expected primary-expression before ‘{’ token error: expected `;' before ‘{’ token Do i have to use cycle, or not-so-much-elegant way like this? myArray[0] = 1; myArray[1] = 2; myArray[2] = 3;

    Read the article

  • why single SQL delete statement will cause deadlock?

    - by George2
    Hello everyone, I am using SQL Server 2008 Enterprise. I am wondering why even a single delete statement of this store procedure will cause deadlock if executed by multiple threads at the same time? For the delete statement, Param1 is a column of table FooTable, Param1 is a foreign key of another table (refers to another primary key clustered index column of the other table). There is no index on Param1 itself for table FooTable. FooTable has another column which is used as clustered primary key, but not Param1 column. create PROCEDURE [dbo].[FooProc] ( @Param1 int ,@Param2 int ,@Param3 int ) AS DELETE FooTable WHERE Param1 = @Param1 INSERT INTO FooTable ( Param1 ,Param2 ,Param3 ) VALUES ( @Param1 ,@Param2 ,@Param3 ) DECLARE @ID bigint SET @ID = ISNULL(@@Identity,-1) IF @ID > 0 BEGIN SELECT IdentityStr FROM FooTable WHERE ID = @ID END thanks in advance, George

    Read the article

  • MVC DropDownListFor not populating the selected value

    - by user2254436
    I'm really having troubles with MVC, in another project I've done the same thing and it worked fine but in this project I just don't understand why the selected item in the dropdown is not populating the class correctly with EF. I have 2 classes: public partial class License { public License() { this.Customers = new HashSet<Customer>(); } public int LicenseID { get; set; } public int Lic_LicenseTypeID { get; set; } public int Lic_LicenseStatusID { get; set; } public string Lic_LicenseComments { get; set; } public virtual EntitiesList LicenseStatus { get; set; } public virtual EntitiesList LicenseType { get; set; } } public partial class EntitiesList { public EntitiesList() { this.LicensesStatus = new HashSet<License>(); this.LicensesType = new HashSet<License>(); } public int ListID { get; set; } public string List_EntityValue { get; set; } public string List_Comments { get; set; } public string List_EntityName { get; set; } public virtual ICollection<License> LicensesStatus { get; set; } public virtual ICollection<License> LicensesType { get; set; } public string List_DisplayName { get { return Regex.Replace(List_EntityName, "([a-z])([A-Z])", "$1 $2"); ; } } public string List_DisplayValue { get { return Regex.Replace(List_EntityValue, "([a-z])([A-Z])", "$1 $2"); } } } The EntitiesList is table in db that have all my "enum" lists. For example: ListID - 0 List_EntityValue - Activate List_EntityName - LicenseStatus ListID - 1 List_EntityValue - Basic List_EntityName - LicenseType This is my model: public class LicenseModel { public License License { get; set; } public SelectList LicenseStatuses { get; set; } public int SelectedStatus { get; set; } public SelectList LicenseTypes { get; set; } public int SelectedType { get; set; } } My controller for create: public ActionResult Create() { LicenseModel model = new LicenseModel(); model.License = new License(); model.LicenseStatuses = new SelectList(managerLists.GetAllLicenseStatuses(), "ListID", "List_DisplayValue"); model.LicenseTypes = new SelectList(managerLists.GetAllLicenseTypes(), "ListID", "List_DisplayValue"); return View(model); } [HttpPost] [ValidateAntiForgeryToken] public ActionResult Create(LicenseModel model) { if (ModelState.IsValid) { model.License.Lic_LicenseTypeID = model.SelectedType; model.License.Lic_LicenseStatusID = model.SelectedStatus; managerLicense.AddNewObject(model.License); return RedirectToAction("Index"); } return View(model); } managerLists and managerLicense are the managers that connect between the entities in db and the MVC UI, nothing special... they contains queries for adding new objects, getting the lists, editing and so on. And the view for creating the License: @using (Html.BeginForm()) { @Html.AntiForgeryToken() @Html.ValidationSummary(true) <fieldset> <legend>License</legend> <div class="form-group"> @Html.LabelFor(model => model.License.Lic_LicenseTypeID) @Html.DropDownListFor(model => model.SelectedType, Model.LicenseTypes, new { @class = "form-control" }) <p class="help-block">@Html.ValidationMessageFor(model => model.License.Lic_LicenseTypeID)</p> </div> <div class="form-group"> @Html.LabelFor(model => model.License.Lic_LicenseStatusID) @Html.DropDownListFor(model => model.SelectedStatus, Model.LicenseStatuses, new { @class = "form-control" }) <p class="help-block">@Html.ValidationMessageFor(model => model.License.Lic_LicenseStatusID)</p> </div> <div class="form-group"> @Html.LabelFor(model => model.License.Lic_LicenseComments) @Html.TextAreaFor(model => model.License.Lic_LicenseComments, new { @class = "form-control", rows = "3" }) <p class="help-block">@Html.ValidationMessageFor(model => model.License.Lic_LicenseComments)</p> </div> <p> <input type="submit" value="Create" /> </p> </fieldset> } Now, when I'm trying to save the new license, when it gets to the db.SaveChanges() in the manager I'm getting: "Validation failed for one or more entities. See 'EntityValidationErrors' property for more details." In breakpoint, the Lic_LicenseTypeID and Lic_LicenseStatusID are getting correctly the ID's from the selected item in the dropdown but the LicenseStatus and LicenseStatus properties are null. What an I missing?

    Read the article

  • c++ Initializing a struct with an array as a member

    - by Drew Shafer
    I've got the following reduced testcase: typedef struct TestStruct { int length; int values[]; }; TestStruct t = {3, {0, 1, 2}}; This works with Visual C++, but doesn't compile with g++ under linux. Can anyone help me make this specific kind of initializer portable? Additional details: the actual structure I'm working with has several other int values, and the array can range in length from a single entry to over 1800 entries. Any help much appreciated. Thanks!

    Read the article

< Previous Page | 337 338 339 340 341 342 343 344 345 346 347 348  | Next Page >