C++, Usleep() Is Obsolete, Workarounds for Windows/Mingw

c++, usleep() is obsolete, workarounds for Windows/MingW?

usleep() works with microseconds. In windows for getting microsecond precesion you should use QueryPerformanceCounter() winapi function. Here you can find how get that precesion using it.

SLEEP: (Sleep or usleep) is not suspending everything in my thread in Linux but it does in Windows? why?

The output is buffered. You don't see the dots, but they are issued like clockwork.

If you add

fflush(stdout); 

or a newline to the output string, you should see the dots appear regularly.

Cross platform Sleep function for C++

Yes there is. What you do is wrap the different system sleeps calls in your own function as well as the include statements like below:

#ifdef LINUX
#include <unistd.h>
#endif
#ifdef WINDOWS
#include <windows.h>
#endif

void mySleep(int sleepMs)
{
#ifdef LINUX
    usleep(sleepMs * 1000);   // usleep takes sleep time in us (1 millionth of a second)
#endif
#ifdef WINDOWS
    Sleep(sleepMs);
#endif
}

Then your code calls mySleep to sleep rather than making direct system calls.

implicit declaration of function usleep

That list is the pre-conditions for having usleep defined. It's basically a C-like expression involving #define variables which has to be true before including the header file.

The header file itself will only define usleep inside what is usually a massive nest of #ifdef statements and the developers have taken the time to tell you what you need to do so that you don't have to spend hours trying to figure it out yourself :-)

Assuming you're using a glibc 2.12 or better, it means you either have to:

• declare _BSD_SOURCE; or
• declare a complicated combination of three other things, which I won't bother to decode.

Probably the easiest fix is to simply compile with gcc -D _BSD_SOURCE or put:

#define _BSD_SOURCE

in the code before you include the header file that gives you usleep.

You'll probably want to define these before any includes in case there are dependencies between the various header files.

Sleep function in Windows, using C

Use:

#include <windows.h>

Sleep(sometime_in_millisecs); // Note uppercase S

And here's a small example that compiles with MinGW and does what it says on the tin:

#include <windows.h>
#include <stdio.h>

int main() {
    printf( "starting to sleep...\n" );
    Sleep(3000); // Sleep three seconds
    printf("sleep ended\n");
}

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