How can I do Multitasking in C or C++

Question

For instance take example of a program which calculates the time you take to type a paragraph and displays the time you took ( at the end ). Here our program is simultaneously performing two tasks : 1.Waiting for user to type ( taking input ). 2.A clock behind counts the time elapsed .

How can I accomplish both the tasks during execution ( at the same time ) . [ OK ! You may think of subtracting final & initial time which we may get by system but I want multitask to take place .]

I tried a lot searching for standard library functions but none of them do it . I think the only way to make multitask happen is smart algorithm of the program which does many tasks simultaneously as well as efficiently . Am I wrong ?

http://stackoverflow.com/questions/266168/simple-example-of-threading-in-c — wjmolina, Mar 17 '14 at 14:16
Do you want a C answer or a C++ answer? The correct idiomatic answers are VERY different. — Fred Larson, Mar 17 '14 at 14:16
It's fairly easy to do multitasking: First, decide if you're coding in `C` or `C++`. Second, choose `C++`. Third, read up on `std::thread`. — stefan, Mar 17 '14 at 14:17
@stefan: Fourth, read an entire book (or maybe several) on concurrent programming to learn about all the issues of synchronization, communication, different threading techniques, etc. — Fred Larson, Mar 17 '14 at 14:20
@FredLarson: Fifth - start pulling your hair out if, even after all your best efforts, you still run into concurrency-related issues, as you inevitably will. — Elias Van Ootegem, Mar 17 '14 at 14:32

djechlin · Answer 1 · 2014-03-17T14:15:31.973

4

Probably multithreading. Use pthreads.

[Although, in your example it's not needed. Just

int time = getTime();
// run program
int endTime = getTime();
printf("%d\n", endTime - time);

]

edited Mar 17 '14 at 14:15

answered Mar 17 '14 at 14:13

djechlin

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@const_ref; Because there is no `std::thread` in C – haccks Mar 17 '14 at 14:17
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@haccks but there is in c++ which is also tagged – const_ref Mar 17 '14 at 14:17
@const_ref; I can see that's why I commented. – haccks Mar 17 '14 at 14:19
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@const_ref When someone tags both C and C++, I think it is fair game to give an answer that works only in one or the other. – crashmstr Mar 17 '14 at 14:20
@crashmstr So why not comment giving the one that works OS independently and is part of the standard. In OP post "searching for standard library functions but none of them do it"..which is of course not true – const_ref Mar 17 '14 at 14:21
If C, then why not `thrd_t`? (Ok maybe because there's barely any C11 compilers, but still :) ) – Lundin Mar 17 '14 at 14:44

score 2 · Accepted Answer · answered Mar 17 '14 at 14:24

2

In C++11 you can use std::thread which is of course part of the standard.

This will not work if using C however or older c++ compilers.

An alternative is boost::thread

answered Mar 17 '14 at 14:24

const_ref

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In C11, there is `thrd_t`. – Lundin Mar 17 '14 at 14:45

How can I do Multitasking in C or C++

2 Answers2