gcc -pthread  -Wall -Wextra -Werror=implicit-function-declaration time/clock_getcpuclockid.c -o time/clock_getcpuclockid -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -lxnet -lsocket -latomic
time/clock_getcpuclockid.c: In function 'main':
time/clock_getcpuclockid.c:12:22: error: implicit declaration of function 'clock_getcpuclockid' [-Wimplicit-function-declaration]
   12 |         int errnum = clock_getcpuclockid(getpid(), &id);
      |                      ^~~~~~~~~~~~~~~~~~~