Use feature test macro for transparent drop-in about c11threads HOT 7 CLOSED

According to the C11 standard, the correct solution would be for client code to look like this:

#ifdef __STDC_NO_THREADS__
    #include "c11threads.h"  // Use home-grown substitute
#else
    # include <threads.h>  // Use standard libc header
#endif

No need to change c11threads.h.

from c11threads.

Not a bad idea, but is there any libc out there which supports C11 threads to test against?

from c11threads.

http://stackoverflow.com/questions/24557728/does-any-c-library-implement-c11-threads-for-gnu-linux

You could try musl.

The latest glibc at least sets __STDC_NO_THREADS__ to 1. Previous versions don't, sigh -.-

from c11threads.

But if you use musl with c11 threads, why would you include this c11thread.h file ?

from c11threads.

Thats the point of this issue: Only include c11thread.h in case your libc does not have C11 thread support.

from c11threads.

You are right.

from c11threads.

The correct way to check for C standard library support for threads at compile time should be

#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) && !defined(__STDC_NO_THREADS__)
#include <threads.h>
#else
#include "c11threads.h"
#endif

A possible solution to automatically use the standard library if available could be to add these lines to c11threads.h, replacing #include "c11threads.h" with the current content of the header.

Note that nowadays all distributions are shipped with a version of glibc supporting threads.

from c11threads.