github.com/afumu/libc@v0.0.6/musl/src/time/clock.c (about)

     1  #include <time.h>
     2  #include <limits.h>
     3  
     4  clock_t clock()
     5  {
     6  	struct timespec ts;
     7  
     8  	if (__clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts))
     9  		return -1;
    10  
    11  	if (ts.tv_sec > LONG_MAX/1000000
    12  	 || ts.tv_nsec/1000 > LONG_MAX-1000000*ts.tv_sec)
    13  		return -1;
    14  
    15  	return ts.tv_sec*1000000 + ts.tv_nsec/1000;
    16  }