clock_gettime(): not found during config due to including the wrong sched.h header instead of the correct time.h

[BalkanMadman]

Hello! We, at Gentoo, work on improving the state of NGINX ecosystem. As part of our efforts, I have been working on better supporting your module.

Getting straight to the point. Your config check checks whether clock_gettime() is available, additionally including the sched.h header.

nginx-vod-module/config

Lines 125 to 145 in 26f0687

	# clock_gettime
	#
	ngx_feature="clock_gettime()"
	ngx_feature_name="NGX_HAVE_CLOCK_GETTIME"
	ngx_feature_run=no
	ngx_feature_incs="#include <sched.h>"
	ngx_feature_path=
	ngx_feature_libs=
	ngx_feature_test="clock_gettime()"
	. auto/feature
	if [ $ngx_found != yes ]; then
	ngx_feature="clock_gettime() in librt"
	ngx_feature_libs="-lrt"
	. auto/feature
	if [ $ngx_found = yes ]; then
	ngx_module_libs="$ngx_module_libs $ngx_feature_libs"
	fi
	fi

This fails, because, according to POSIX and GNU, the clock_gettime() function is provided by time.h, not sched.h.

Thus, the line

nginx-vod-module/config

Line 130 in 26f0687

ngx_feature_incs="#include <sched.h>"

should be changed to

ngx_feature_incs="#include <time.h>"

to check for clock_gettime() properly. I will follow this issue with a PR fixing this.

[BalkanMadman]

Moreover, even with the correct header the check still fails, as the function expect two arguments, but none are provided.

The line

nginx-vod-module/config

Line 133 in 26f0687

ngx_feature_test="clock_gettime()"

should be changed to something like

ngx_feature_test="clockid_t c; clock_gettime(c, NULL)"