Param1 but data structure of param1 different..call made from 2 different places

Hello guys Good evening I am electrical student semester three I have c++ and it is difficult to me I need tutors or expert to help me in excersise or assignment or project and he or she will be paid if he or she needs money for that Thanks

Please people Any expert or tutor any c++ can help me

Im unable to install gcc

I have best online free courses with certificate you can apply in website please DM me

Is it must to pay or just for free😳???

Free

And is it possible for me to involve as a beginner

Absolutely

Thanks a bunch ankita , I really thank u for sharing me this important opportunity👍👍👍

I have main.cpp and header.h. In CMakeLists.txt I write: add_executable(main main.cpp header.h) There is a function defined in header.h and its prototype in main.cpp, I don't #include header.h in main.cpp. The problem is that linker can't link function prototype from main.cpp with its definition in header.h. But it's enough for me to rename header.h to header.cpp (in CMakeLists.txt also) and everything works as intended. What's wrong? (And yes, I know that defining function in a header is not the best practice).

Because the Header file is not included in the main.cpp The linker doesn't link between headers and .cpp files Header files act only as interfaces to other source files and also it can consist of implementation Actually, it's just a copy - paste procedure in inclusion of the header files

I have best online free courses with certificate you can apply in website please DM me

!report

She hasn't done anything , she is helping us in education ,why you reported, it's unfair !! please admins don't ban ankita if you ban ankita ban me and also my friends I'll tell them to leave the group , ankita hasn't done nothing but she has shared us an important thing

She hasn't done anything , she is helping us in education ,why you reported, it's unfair !! please admins don't ban ankita if you ban ankita ban me and also my friends I'll tell them to leave the group , ankita hasn't done nothing but she has shared us an important thing

I have some questions about coroutine s. 1.how to calculate the size of coroutine frame,. 2.where is executing stack of coroutine,. 3.how to execute coroutine on a different thread Plz help me.

Just want to add that false sharing can happen even with your data being cache aligned. You need to do more to prevent false sharing apart from just aligning the data with L1 cache

Because the Header file is not included in the main.cpp The linker doesn't link between headers and .cpp files Header files act only as interfaces to other source files and also it can consist of implementation Actually, it's just a copy - paste procedure in inclusion of the header files

Declaring a parameter passed by value as const is useless. For ex if you have 2 functions void fun(int n){} void fun(const int n){} the compiler will complain about redefinition because both the functions are equivalent to the compiler from the caller's point of view.

> You need to do more to prevent false sharing apart from just aligning the data with L1 cache Interesting, I don't know much about this, care to shed some light about the "do more" part? Or maybe a keyword for me to google is nice.

1. Here are two papers that you can go through. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0981r0.html http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1365r0.pdf The first deals with the situation in which heap allocations for coroutines can be optimized away and the second one deals with conditions whereheap allocations is not possible. There is a dirty way to find the size of the frame needed for a coroutine by overloading operator new and capturing the size of the bytes required provided your use case doesn't fall into the cases listed in paper one. Apart from this there is no standard way to do so. 2. Mostly on the heap but read the papers above. 3. Run the resume function for the coroutine handle in a different thread.

Well assuming that your data is cache aligned and is occupying an entire row of the cache (thus not sharing the row with other unrelated objects). Now if multiple threads in your application access different parts of your datastructure and update them separately, you will still have issues with false sharing where the updates result in unnecessary retrievals from the memory. The way to prevent this is by using thread specific mapped variables. You can read about it here : https://wiki.cdot.senecacollege.ca/wiki/Team_False_Sharing In one of the examples, they deal with the usecase I gave above

Ok, it makes sense. Just to confirm my understanding, assuming I have struct my_data { int a; int b; } ____cacheline_aligned_in_smp; I have 2 cores, Core 0 updating a, Core 1 updating b, they both (a and b) are completely independent with respect to the given task. Then false sharing happens since both in the same cache line. If I do ____cacheline_aligned_in_smp int a; ____cacheline_aligned_in_smp int b; given the same situation as above, false sharing does not happen. Is that correct?

Well assuming that your data is cache aligned and is occupying an entire row of the cache (thus not sharing the row with other unrelated objects). Now if multiple threads in your application access different parts of your datastructure and update them separately, you will still have issues with false sharing where the updates result in unnecessary retrievals from the memory. The way to prevent this is by using thread specific mapped variables. You can read about it here : https://wiki.cdot.senecacollege.ca/wiki/Team_False_Sharing In one of the examples, they deal with the usecase I gave above

Ok, it makes sense. Just to confirm my understanding, assuming I have struct my_data { int a; int b; } ____cacheline_aligned_in_smp; I have 2 cores, Core 0 updating a, Core 1 updating b, they both (a and b) are completely independent with respect to the given task. Then false sharing happens since both in the same cache line. If I do ____cacheline_aligned_in_smp int a; ____cacheline_aligned_in_smp int b; given the same situation as above, false sharing does not happen. Is that correct?

Yes but this wastes precious L1 cache space. A better way to do this would be using thread private data.

#include <stdio.h> #include <string.h> int check_passwort () { char eingabe [0 x10 ]; gets(input ); return !strcmp(eingabe , "password"); } void zugang () { printf("Welcome!\n"); execve("/bin/sh", NULL , NULL ); // Starts a shell. } int main(int argc , char** args) { printf("Enter your password: "); if ( check_passwort ()) { zugang (); } return 0; }

Can someone help me with a C++ Problem, please ?

I am having problem with these commented lines (these concepts) in the following code.. please guide me or refer something which can teach me these concepts easily. class Node{ public: int key; int data; Node* next; // not getting this step // please explain two constructor concept or refer something Node(){ key = 0; data = 0; next = NULL; } Node(int k,int d){ key = k; data = d; next = NULL; } };

in python i=0 while (i<4): print(f"blabla{i}") i=i+1 # output blabla1 blabla2 blabla3 how can I do with c plz

thank you first . no this just example I wan to declare various file in one line like int main() { FILE*fp; for(int i=0.....) fp{i}=open(fp"name_file{i}","w");

Use an array of file pointers. C is not Python. There are limitations to what you can do.

so I can't do that !

No you can't dynamically construct variable names in C. It is statically typed language. The file names (the name of the file that you pass in as a const char* argument) can be constructed dynamically but. You just have to use one of the format methods like snprintf.

it is too slow like using vscode,

why is using namespace std is not recommended by many programmers in C++ ?

In python, you can use the walrus operator or range to make it more concise. In C, you can do while(i < 4) printf("blabla %d \n", i++);

Hi all, I need some help here #include<iostream> #include<string> using namespace std; class Books { public: string author; float cost; string tittle; string publisher; float account_number; int copies; void setdata(); }; { cout<<"\n Enter the following details:\ I'm getting the error : expected unqualified id before '{' token. after the class, any idea where i might be wrong