C/C++ :: How Compiler Perform Padding In Size Of Structure
Oct 9, 2013struct st
{
char a;
short b;
char c;
}
what will be size of structue.
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C :: Structure Padding To 16 Bytes For Use With Atomic Instructions
Jun 30, 2013I am using atomic instructions on x64 and variables so used must be 16 byte aligned.
I use a number of structures where their members are so operated upon.
The structures accordingly needs must be 16 byte aligned and padded - their internal members must be on 16 byte boundaries and, crucially, there must be tail padding to a 16 byte boundary, so I can allocate arrays of these structures and use pointer math to iterate. (I am naturally using aligned malloc).
The problem I am finding is that it is not apparent to me how to achieve this end. Here below we have a test structure (currently I'm working with the latest Amazon Linux GCC, 4.6.3, on x64);
Code:
#define LFDS700_ALIGN_DOUBLE_POINTER 16
#define LFDS700_ALIGN(alignment) __attribute__( (aligned(alignment)) )
LFDS700_ALIGN(LFDS700_ALIGN_DOUBLE_POINTER) struct test_element
{
struct lfds700_freelist_element
[Code] ....
I allocate an array of test elements, thus;
Code:
te_array = abstraction_aligned_malloc( sizeof(struct test_element) * 100000, LFDS700_ALIGN_DOUBLE_POINTER );
The problem manifest is that sizeof(struct test_element) is 40 bytes! So the second element does not begin on a 16 byte boundary and we all fall down. Printing the addresses of the first element in the test element array, I see the following;
Code:
(gdb) print *ts->te_array
$2 = {fe = {next = {0x7fffec0008d0, 0x2}, user_data = 0x7fffdc0008d0}, thread_number = 3, datum = 0}
(gdb) print sizeof(struct test_element)
$3 = 40
(gdb) print &ts->te_array->fe.next
[Code] ....
So we see fe->next is the first element and so is correctly aligned curtsey of aligned malloc, where fe->next is 16 bytes, fe->user_data is correctly aligned, but then te->thread_number is misaligned and te->datum is given eight bytes rather than four, leaving us in the end without correct tail padding to a 16 byte boundary.
So, what gives? how *am* I supposed to indicate to the compiler it must pad structures to 16 byte boundaries?
C++ :: Compiler Time Checker - Invalid Application Of Size Of To Function Type
Nov 30, 2014I have this piece of code from the book "Modern C++ Design" that checks for compile-time error. When i tried to compile it, i get the error "invalid application of size of to function type". How to make this compiler-time checker work?
Code:
template<bool> struct CompileTimeChecker{
CompileTimeChecker(...);
};
template<> struct CompileTimeChecker<false> {};
[Code] .....
C++ :: Size Of Structure Pointer
Sep 2, 2014Is there way to find the size of structure pointer size? When we tried to get the size of structure pointer will get size of address(@ location) which would be 4 bytes long. But I want to get the size of all structure members size using structure pointer.
View 1 Replies View RelatedC/C++ :: Size Of Empty Structure?
Nov 8, 2014 I have a doubt related Size of empty structure. I know the answer of empty structure is "0".
How and why the Result got ZERO..??
C++ :: Add Padding In BMP Image
Feb 1, 2015I am working on pset4 in the CS50 online coarse. The goal is to resize a bmp image. I have it working except adding the padding back to new resized image. The image I am using uses 3 bites of padding. If the factor I resize the image by works out to have 3 bites of padding it works perfect and if the image has no padding it works perfectly I need a fresh pair of eyes. I am not sure how to add the images so here is the address to download the images and the skelton of the source code they gave to modify. [URL] .... The image that requires the padding is labled as small.bmp.
#include <stdio.h>
#include <stdlib.h>
#include "bmp.h"
int main(int argc, char* argv[]) {
// ensure proper usage
if (argc != 4)
[Code] .....
C++ :: Zero Padding / Convert 2.3 To 0002.3?
Aug 12, 2013i want a C program to convert 2.3 to 0002.3 . Any in built function is there for this conversion?
View 10 Replies View RelatedC++ :: Zero Padding To A Float Number?
Aug 12, 2013I want to convert a float number like 2.3 to 0002.3.Is therany inbuilt function in C/C++ for this.
View 4 Replies View RelatedC++ :: Padding Zeroes Onto A Binary Number
Feb 24, 2014The following piece of code is supposed to output the binary representation of a given integer and it does exactly that. However, if the given integer is 2, then output is 01. Is there a way to make the program output 0001. I am working on a C program that outputs 4-bit gray code.
#include <stdio.h>
#include <math.h>
int main(void) {
long int n=2;
while (n) {
if (n & 1)
printf("1");
[Code] ......
C/C++ :: Cannot Display Items In File To Do A Receipt And Use Padding
Oct 21, 2014#include<iostream>
#include<fstream>
#include<iomanip>
#include <sstream>
using namespace std;
string padLeft(string,char,int);
string padRight(string,char,int);
string fromMoneyToStr(double);
[Code] ....
And don't know how to use padding functions so I can space my receipt.
C# :: Perform Web Request And Get Results?
Sep 17, 2014Here is the site that I want to interact Genderchecker
I want to set a value to a specific element in a web site. Perform a click on an element that is image. Get the result <span> text into string variable...
What should I use ?
C++ :: Simplest Way To Perform Attribute Match?
Aug 2, 2013I have a input record like
acct|N|Y|N|N|rose@gmail.com
Now I need to create a logic to append a code to the end of the file using the following matrix rules.
00NNNN
01NNNY
02NNYN
03NNYY
04NYNN
05NYNY
06NYYN
07NYYY
[code].....
In the above example these four flags are "N|Y|N|N", so I need to append the matching code at the end of file "04".
desired output :
acct|N|Y|N|N|rose@gmail.com|04|
as it matches code '04':
04NYNN
C/C++ :: How To Perform Data Validation For Emails
May 15, 2013I have this big project and I need to do data validation for an email.
View 1 Replies View RelatedVisual C++ :: How To Keep Within Boundaries And Perform The Function
Dec 26, 2014I am really unsure how to keep within the boundries and still perform the function I need. My code functions normal when I have both categories 'buy' and 'sell' in the queue which is my main goal and I should be clocked out on this function BUT, If the queue is missing all 'sell' data, it segment faults.
I don't want to change any of the functionality, just get rid of the segment fault error. It appears b < buydat.size() and buydat[b+1] are in conflict. The purpose of the algorithm is capture the record sets in groups of 7 from data coming in from the www as strings. In that group/set, I pattern match for the string 'Buy' and if true, insert record into vector for processing. I also need the price (y = 3)
How do I capture buydat[2] and buydat[3] in groups of 7 without a segment fault?
Code:
void buymngr(){
//vector defs
vector<std::string> buydat;
vector<std::string> markdat;
vector<std::string> pricedat;
vector<std::string> qworkcoin;
buydat = getmyData();
[Code] ....
When one buy and one sell are sitting in the queue. Code functions as expected:
gentoo-mini # ./masterMain
Code:
I got my own data
I just got market buy data
Bork!
Bork2!
You 'do' have buy string match data!
my max price is 0.00492975 at position 0
[Code] ....
C++ :: Perform Subtraction Between Two Objects And Put Result In Third Object
Sep 19, 2013trying to understand operator overloading, and i wrote some code just to define a "-" operator to do a simple subtraction. SO, i wrote a program that can perform a subtraction between two objects and put the result in the third object. now I Just cant show the result on the console. And also can anyone define the meaning of [b1.x], like I want to know am I assigning the value to the "b1"object or the x variable? This is a very concept that I need to understand.
#include<iostream>
using namespace std;
struct Ok
{
int x;
int y;
};
Ok operator-(const Ok& a , const Ok& b)
{
Ok result;
result = (a - b);
return result;
}
int main()
[Code]...
C# :: Possible To Perform Database Operation In Windows Service
May 29, 2014I had created windows service .from that i just want to insert data into database . It is successfully installed but it is not started. It gives an error service could not started...
View 14 Replies View RelatedC# :: Fetch Datatable Values To Perform Some Operation
Dec 16, 2014I am having some column say "Response" column in my Datatable.Now I want to fetch this particular column value and compare this value with the maximum response how to fetch and compare it in C#.net .. This is my code.
for (int i = 0; i < DataFilter.Rows.Count; i++) {
DataRow dr = DataFilter.Rows[i];
DataView dv2 = new DataView();
dv2 = DataFilter.DefaultView;
[Code] ......
C++ :: Perform Arithmetic Operations With Template Parameters?
Jul 13, 2013 how to use template parameters to perform arithmetic operations on objects.
I feel that it would best to demonstrate my issue rather than try and explain it.
Sample:
// Fundamental object structure
template<int T> struct myInt
{
myInt() { value = T; };
[Code]....
What I don't know is how to get a hold of the T variable to add them through the 'add' structure. Also, might any of this have to do with sequence wrappers?
seq_c<T,c1,c2,... cn> is essentially what I'm thinking of. Where T in this case is the type and c to the nth c are the values.
C :: Unable To Perform In Order Traversal In Binary Tree
Jan 16, 2014Following is the code for inserting elements in a tree and then retrieving them back using inorder traversal technique elements are getting inserted just fine,but the code doesn't displays the elements of the tree while performing inorder traversal..
Code:
#include<stdio.h>
#include<stdlib.h>
struct node{
int data;
struct node *right;
struct node *left;
}*z,*t,*root=NULL,*x=NULL,*y=NULL;
[Code]....
Visual C++ :: Create A Program That Perform Same Calculation For Every Oscillation
Jan 17, 2014I am reading from a text file and want to create a program that will perform the same calculation for every oscillation.
The text file I'm reading from is attached to this post. A3.txt
The program that I've written is as follows:
Code:
#include <iostream>
#include <fstream>
using namespace std;
int main() {
ifstream inFile ("AP1.txt");
ofstream results_file ("APDuration.txt");
[Code]...
Where I'm having trouble is in having the inFile.seekg function iterate to the next series of values.
Here is what the data file looks like in a graph:
In a nutshell, my program will read the duration of each action potential from a point called "dVmax" (where the upstroke is at its maximum upward rate of change) to the point of 90% repolarization (on the downstroke where 90% of the total wave amplitude is subtracted from the volts at peak amplitude).
If you would like to test my program on one action potential, here is one action potential : AP1.txt
C++ :: C Type Strings - Program To Ask User To Enter A String And Perform Functions
Oct 18, 2014My assignment is : Please use C type strings ( array representation of strings). Write a program that will ask the user to enter a string. It will then regard that string as a worked-on string and allow the user to perform the following editing functions on it:
s – search
i – insert
a – append
d – delete
a – append
d – delete
r – replace
e – exit
s – search
This option will allow the user to search for a specified string in the worked-on string. If the string is
found, it will display the starting index (position) of the searched string in the worked-on string.
here is what i have so far.
#include <iostream>
#include <cstring>
using namespace std;
int main() {
char a_string[80];
[Code] .....
C/C++ :: Not Able To Initialize Structure Variable Inside Main Whose Structure Defined GL
Aug 27, 2013I am trying to run a programme implementing a function with structures in c... which is:
#include<stdio.h>
#include<conio.h>
struct store {
char name[20];
float price;
int quantity;
[Code] .....
C++ :: How To Use Structure Pointer Through A Structure Public Member Definition
Dec 7, 2014Why doesn't this compile?
struct hi(){
void other();
}histructure;
void hi::other(){
std::cout << "Hi!" << std::endl;
[Code] ....
Makes no sense the structure is written before the structure member function is called so why is there compile errors ??...
Visual C++ :: Change Frame Window Size According To Increase In Font Size
Nov 27, 2012Change the frame window size according to font size increases.
View 3 Replies View RelatedVisual C++ :: Text Size In Screen Is Different From Size In Print Preview?
Feb 1, 2013I must take an old MFC project in VC++ 6.0 and make changes.
The problem is text size in screen is different from size in print preview.
for example with this font
Code:
CFont f50;
f50.CreateFont(100,0,0,0,FW_BOLD,0,0,0,DEFAULT_CHARSET,OUT_DEFAULT_PRECIS,
CLIP_DEFAULT_PRECIS,DEFAULT_QUALITY,FF_DONTCARE,"Frutiger LT Std 45 Light");
And this text
Code:
s=_T("Let's try to calculate the size of this text");
and with MM_LOMETRIC map mode
GetTextExtent() returns me:
On screen: (1595,99)
Ink printer + print preview: (1589,100)
PDFCreator + print preview: (1580,100)
comparing with screen size the height is bigger but lenght is smaller. I don't understand.
I can understand that different printers process the fonts in different way and then to have different lenghts. That's not the problem. The problem is I need to simulate in screen the same behaviour i will have on printer because these texts are being aligned in the document, and I don't want to see that the text si aligned different in text than in paper.
What can I do to render the text on screen with the same size I will have on the printer? Print preview is doing it. Should I change the font parameters? is something related with pixels per inch?
C/C++ :: Value Assignment To Structure Member Inside The Structure?
Oct 7, 2014Is it possible to assign a value to structure member inside the structure.like.....
struct control{
char tbi:2 =0;
char res:1 =0;
};