I am using thread on VC 2012 (very close to VC 2010). When the argument list is short, it works fine. However, when I add a function with more arguments, the compiler indicates "no thread constructor match the argument list....etc", and when I reduce the number of arguments, it works.
Is there a limit about thread constructor? I didn't see this in ISO C++11 standard. How can I fix this limit?
I have a class which I wrote and one of its object is "SerialPort" .NET class. In my MainWindow I created instance of my class called "SerialPortComm", then I send through some functions of mine, commands to the Serial Port, and I receive answers through "DataReceived" event.
But when I trying to use Dispatcher.BeginInvoke to write my data I have received (successfully), nothing shows on the RichTextBox which I'm trying to write to.
What can caused that, and How I can make it works?
SerialPortComm.cs
public partial class SerialPortComm : UserControl {
public SerialPort mySerialPort = new SerialPort();
public void Open_Port(string comNumber, int baudRate) {
mySerialPort.PortName = comNumber;
mySerialPort.BaudRate = baudRate;
[Code] ....
What I have is a main function that takes input characters from the command prompt during the main function call, and coverts it to an integer array a using atoi. (starting at the 2nd character - the 1st is reserved for another call that I plan to reference later, and the 0th is obviously the ./function). A function is then called to find the mode of an array (the range of values in the array is 1-30). Now, when I run the whole thing, I get a segmentation fault (core dumped) for even number of arguments. It's late and I've been staring at it for too long...
Code:
#include <stdio.h>
#include <stdlib.h>
int get_mode(int a[], int count);
[Code]......
Write a function write with variable number of arguments that takes a string first argument followed by any number of arguments of type double and prints on the screen a string formatted by the rules described below. The first argument may contain formats in curly braces of the form {index[:specifier]}, where the square brackets show optional parts (this is :specifier may be missing), and index is the sequence number of an argument of type double (starting from sequence number 0).
Rules for formatting: In the printed string the curly brackets and their content will be replaced by the argument with the given index, formatted according to the given format specifier. If the format specifier is missing, the argument will be printed with its default format. For example:
write("The number {0} is greater than {1}.", 5, -3);
will print
The number 5 is greater than -3.
write("There are no format specifiers here.");
will print
There are no format specifiers here.
The format specifiers and their meanings are listed in the following table
Specifier MeaningFormat Output for 1.62 Output for 2.0
none default {0}1.62 2
ccurrency{0:c}$1.62 $2.00
escientific{0:e}1.620000e+000 2.000000e+000
ffixed point{0:f}1.620000 2.000000
iround to int{0:i}2 2
Limitations: You may limit the maximum number of arguments your function can process to a certain value, for example 10.
Suggested extensions:
-Add an optional alignment specification in the format , e.g., make the format of the form {index[,alignment][:specifier]}, where alignment is an integer specifying the width of the field in which the corresponding argument will be printed. If alignment is positive, align to the right, if it is negative, align to the left.
-Accept an optional integer after the specifier letter, specifying the required precision in the output. For example, {0:f2} will print the number 1.6234 as 1.62, but {0:f5} will print it as 1.62340.
i'm trying building my how Write() function:
template <typename T>
....
Write(T Argument1[,T ArgumentX])
how can i calculate the numeber of Arguments added? (in C we used an argument for tells how many we putted in a function, but not in these case)
I need to create dynamic string by given format(%d,%s,%f,%lf,%c) using variable number of arguments in function. This code gives me an error(main.exe has stopped working):
Code:
#include<stdio.h>
#include<stdarg.h>
#include<string.h>
#include<stdlib.h>
char *form(char *format,...);
char *form(char *format,...)
[Code]...
I assume the error is in functions(itoa,fcvt,ecvt).
I need to create dynamic string by given format(%d,%s,%f,%lf,%c) using variable number of arguments in function. This code gives me an error(main.exe has stopped working):
#include<stdio.h>
#include<stdarg.h>
#include<string.h>
#include<stdlib.h>
char *form(char *format,...);
char *form(char *format,...)
[Code] ....
I assume the error is in functions(itoa,fcvt,ecvt).
So, I'm supposed to do : Create a function with unlimited number of arguments, which forms a dynamic string based on the following form (%d, %s, %f, %lf, %c), with the following prototype:
char*create(char*form, ...);
The function is supposed to have the following output:
create("Peter is %d years old and is in %s-%c class.",7,"second",'A');
-> Peter is 7 years old and is in 7-A class.
create("His GPA is %lf.",4.96);
-> His GPA is 4.96.
create("His favourite subject is math!");
-> His favourite subject is math!
I've managed to do the following :
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
char *create(char *form, ...) {
char *res =(char*)calloc(1,1),*pos_int,*pos_float,*pos_str,pos_char,*pos_long;
[Code] ....
The part with %d and %s string was not that hard, but now I'm supposed to convert %f and %lf to string, I've tried using sprintf but I've had no luck so far, another problem is the fact that I've gotta use lists to complete the task. I've been trying to convert float to string for the past 2 hours, but I'm drawing a blank now.
Write a function that takes 3 arguments. The function has to bring back a new number that has been generated with the replacement of the figure that is on a given position in the number with a figure that is been transferred as an argument(have in mind that the position of the figure is being counted from right to left,starting from one). Write a main program in which the newly formed numbers will be printed for numbers of a range written by the user.
Example: if you wrote the numbers 2276,3 and 5 the function should bring back the number 2576
If you didn't understand the text, the example shows that in the number 2276, the number has been counted from right to left by the second argument "3" and in the place of the figure "2" has been put the figure "5".
This is where I got stuck, I can't figure out how to make the replacement.
int argument(int x,int y,int z) {
return 0;
} int main() {
int a,b,c;
printf("Enter a value for a(100-999):");
scanf("%d",&a);
[Code] ....
I just started learning C++ a week ago and have been stuck on a project for the past 2 days now. I am building a limited purpose calculator which finds the value of one of five operations. Visual studio doesn't underline any errors in my program but every time I try to run it I get an error message. I believe it has something to do with the if/else but Im not sure.
#include <iostream>
using namespace std;
int main(){
int a;
int b;
int sum = a + b;
[Code] ....
Code:
do {
printf("Edit the entry's cellphone number:");
scanf("%s", addressbook[4][num]);
length = strlen(addressbook[4][num]); //gets the length of the input (should be 10)
//checks if the input is composed of 11 elements wherein the first 2 are 0 and 9 respectively
for(i=0; i<11; i++){
[Code] ....
why do I get an error here?
Code:
if ((addressbook[4][num][0] == '0') && (addressbook[4][num][1] == '9') || (addressbook[4][num][i]>='0') && (addressbook[4][num][i]<='9') && (length=='11'))
And how do I fix this?
The error message is: comparison is always false due to limited data type
I'm currently working on the ioquake3 engine . The ioquake3 engine is separated into 2 different main threads at runtime: the gamecode and the engine. Both are communicating but not all information and my problem resides here.
In the gamecode, there's a struct called gentity_t which contains a lot of fields:
Code:
typedef struct gentity_s gentity_t;
struct gentity_s {
entityState_ts;// communicated by server to clients
entityShared_tr;// shared by both the server system and game
// DO NOT MODIFY ANYTHING ABOVE THIS, THE SERVER
// EXPECTS THE FIELDS IN THAT ORDER!
//================================
struct gclient_s*client;// NULL if not a client
[Code] ....
This whole entity is passed to the engine at runtime, but only the first two fields are declared for the engine:
Code:
// the server looks at a sharedEntity, which is the start of the game's gentity_t structure
typedef struct {
entityState_ts;// communicated by server to clients
entityShared_tr;// shared by both the server system and game
} sharedEntity_t;
My problem is that I need to access the health field of gentity_t from the engine. Technically, this is possible, but the health field is not declared in sharedEntity (which is the same memory address than gentity_t in the gamecode), so this is not straightforward.
I am looking for an elegant way to do this, and my constraint is that I must not edit the gamecode, only the engine.
The solutions I've thought:
- Just copy the whole gentity_t fields into sharedEntity_t. This would work I think but would be redundant, and I would like to avoid copying this huge set of fields.
- Include the two headers files declaring the gentity_t and sharedEntity_t structs, and create a Getter and a Setter functions that would cast a gentity_t over a sharedEntity_t and return/set a field. The problem is that I can't simply include them because they are both including some common headers files and this produce a recursive include error (and I can't modify the files to add a check, these are normally in the gamecode).
- Directly access the health field using a clever memory pointer, but I don't even know if that's possible given the huge number of fields prior health with many different types?
I have small Project In Vs 2013.i have to deploy it.but i did through Installshield. Project is working same PC but when i try to deploy another PC i cannot loin in to my project.it seems to me that i didn't add database .
View 2 Replies View RelatedI can do the folowing:
float var1 ;
var1 = 9.12345 ;
printf("%.2f",var1) ;
the output will be 9.12. What if I wanted to save that as another separate float with displaying it on screen?
I have the following code below. I am getting a memory access violation when accessing cmd->query_string in the loop function. The loop() function is running in another thread. The cmd object appears to be destroyed after calling the send_command function. How do I create an object on the heap and access the query_string.
std::list<my_command_message_que*> my_command_que;
void loop(){
if(my_command_que.size() > 0){
my_command_message_que * cmd = my_command_que.front();
std::cout << cmd->query_string;
[Code] ....
I've been using threading for a while, that was no needing parameters. so I used for example the following line :
_beginthread(functionName, 0, (void*)10);
and it worked great...
but now I have a function that has an int parameter (int num), and I dont know how to transfer it using _beginthread...
I was working on a problem that was best solved with chaining threads together using a blocking thread-safe queue. Eg threads A and B pass data to each other using a queue ... a simple producer consumer design A -> B. This has two benefits: 1) being that there is a buffer between the two threads to cache for a slow consumer and 2) allows for better throughput when loads of data are high because the two can run in parallel. Most of the time the design works well under load. but I found when pushing data through the threads intermittently, i.e. once about 0.5 seconds it ran poorly, mostly from what seemed to be latency introduced during the OS waking up of the consumer thread B.
What i have come up with to solve this issue is what i call an .... Its a wrapper around a basic thread safe queue and adds one extra function called .... The idea here is that if you have a simple case (or perhaps a slightly more complicated case) of two threads in a prod cons design and you know the producer will create or received the data, process it, and then push onto the queue, why not give the consumer thread a heads up to let it know the data is about to arrive. In this case call .... In this way you can have the consumer thread in a polling state anticipating the arrival of data and avoid the time to schedule it back to a running state.
Anyway, i have some code below and I was looking to get some feedback. I have tested it somewhat and it does improve the responsiveness quite substantially.
I don't know if I've setup the thread correctly or not, but its behavoir isn't what I'd expect. I'm creating the thread within a BN_CLICKED message
typedef struct my_TNFO {
HANDLE h_event;
HANDLE h_thread;
DWORD thread_id;
BOOL running;
BOOL init;
BOOL canceled;
[Code] ....
progd->count was devised to stop the thread when the recursion ended by posting a message to the main window. When it reaches 1, the def procedure sends the WMU_DISC_DONE message to set the event
All that *appears* to work; however, if I cancel the recursion thread, the list view continues to populate for a bit and then deletels all but 1 item though I send the message LVM_DELETEALLITEMS.
If I move the (tmp->canceled == TRUE) test inside of the do-while, the app gets loopy.
Startthread get called to launch to update list box.
a)is it the only way to pass string to the PostMessage?. my concern is that allocate using new in each iteration each time slows it down a bit.
b)does OnAddToListBox look memory leak free?.
c)What is the best way handle m_pThread at the end?. Any way to improve it?.
Code:
UINT CMyDlg::Dump(LPVOID lparam) {
HWND *pHndl = static_cast<HWND *>(lparam);
char buffer[200];
for (int i = 0; i < 100; i++) {
sprintf_s(buf,"user %d, data %s",i, "Connected");
[Code] ....
I use MFC Find console window and send key to console like this.
Code:
HWND w;
w = FindWindow(NULL, L"c:userspkrudocumentsvisual studio 2010ProjectsCleanVirusDebugCleanVirus.exe");
[Code]....
After program process success in console it not close console windows but it show like this in Output
The thread 'Win32 Thread' (0x1300) has exited with code 0 (0x0).
I think if I can check when VC will show this line, then I can use FreeConsole(); for close console windows.
There are gnu thread, c thread, posix thread and win32 thread which all can be used on windows platform.
How, why and when do I need them?
Code:
#ifndef C_THREAD_H_
#define C_THREAD_H_
extern "C"
{
#include <cthread.h>
[code]....
This simply won't compile with Visual C++ because there isn't any cthread.h header file there.
I want to add a timer(clock) to my application so that it displays the system time and refreshes every second.
I have this code but it only fires once.
// this is at the top of the application
Code:
HANDLE m_threadClockTime= NULL; Code: int APIENTRY _tWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPTSTR lpCmdLine,
_In_ int nCmdShow)
[Code] ....
But this code only fires once? How can I get this to fire every second (without locking up the entire application in between)....
How to call a thread by a function pointer?
I get "error C2059: syntax error : '(' " on the indicated line.
Code:
#include <windows.h>#include <iostream>
using namespace std;
DWORD WINAPI Thread() {
cout << "ok" << endl;
return 0;
[Code] ....
I am writing a program, the trouble is is that it uses a single thread and is SLOW.
View 10 Replies View RelatedAfter i've created a thread,
Code:
Thread thread = new Thread(new ThreadStart(alpha.ThreadProc)); h
How to wait for that thread to finish without using Sleep?
I have a small problem with my program. It is kinda a mess but I will try to explain you what I am trying to do. I have some threads. One of it, it attempts to detect a game client. So my code is sort of like that:
DWORD ProcessID; // The process ID of the game client
void test() {
char* text;
[Code]....
So basically, its like the variable changes, but only inside the thread... why does that happen?
