Time operation functions accurate to microseconds in Linux

Linux time-based operation functions accurate to microseconds-general Linux technology-Linux programming and kernel information. The following is a detailed description. In Linux, if the time is computed in seconds, I believe everyone has used time and other functions to implement it. But what should I do more accurately? What about milliseconds and microseconds?

Take a look at the following source code to understand:

# Include
# Include
# Include

Void function ()/* is a function that consumes a certain amount of time and has no practical use */
{
Unsigned int I, j;
Double y;
For (I = 0; I <10000; I ++)
For (j = 0; j <10000; j ++)
Y = sin (double) I );
}

Int main (int argc, char ** argv)
{
Struct timeval tpstart, tpend;
Float timeuse;

Gettimeofday (& tpstart, NULL );
Function ();
Gettimeofday (& tpend, NULL );
Timeuse = 1000000 * (tpend. TV _sec-tpstart. TV _sec) + tpend. TV _usec-tpstart. TV _usec;
Timeuse/= 1000000;
Printf ("Used Time: % f \ n", timeuse );
Exit (0 );
}


The gettimeofday function is used, and this structure is used in the function:

Struct timeval {
Long TV _sec;/* seconds */
Long TV _usec;/* microseconds */
};
Needless to say, Do you understand everything else?