Timer Setting

[Pramod Sharma]

Clock resolution as mentioned in the man page of system call 'setitimer' is 1/HZ sec and value of this constant 'HZ' is defined in include file ,which is 100 . That means the smallest interval timer can only be 10 ms .Is there anyway by which we can reduce it to say 1/10 ms or 1 ms as desired by our application.What is the smalles clock resolution we can get on the system .we are using system HP-UX workstation b2600.

[Graham Cameron_1]

Hi

In the context of setitmer it looks like you are right.

However, the kernel can handle much smaller time increments, via the selct() or nanosleep() calls.

see "man nanosleep".

NB also
# getconf CLOCKS_PER_SEC
1000000
# getconf CLK_TCK
100

Hope this helps.

-- Graham

[A. Clay Stephenson]

You want to make use of the gettimeofday() system call. Although it has microsecond precision the actual resolution is typically a few milliseconds.