has_vdso.cpp File Reference

Check whether the vDSO is used on this computer. More...

#include <cppthread/thread.h>
#include <libexcept/file_inheritance.h>
#include <iostream>
#include <string.h>
#include <snapdev/poison.h>

Include dependency graph for has_vdso.cpp:

Go to the source code of this file.

Functions
int	main (int argc, char *argv[])
void	usage (char *progname)

Detailed Description

This tool is expected to be used in your scripts to know whether a given process may fail because it is off time wise (i.e. the process uses the time(2) function which can be off by up to 1 second).

You can simply use it in an if statement like so:

if ! has-vdso -q
then
    echo "warning: our process won't work right on this platform..."
fi

Note

I seem to have such an issue on an ARM64 CPU. So the test above may also require you to test the architecture. I don't recall ever having such an issue on an Intel based computer (I nearly only used computers with Intel processors since I stopped using my SGI computers).

See also

https://man7.org/linux/man-pages/man7/vdso.7.html

Definition in file has_vdso.cpp.

Function Documentation

main()

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 80 of file has_vdso.cpp.

usage()

void usage

(

char *

progname

)

Definition at line 70 of file has_vdso.cpp.