Crate tpom

source ·
Expand description

TPOM

Allows replacing time-related functions in the vDSO (1, 2) with user-provided functions.

Only works on Linux. Is currently limited to x86_64, though it could be extended for other architectures.

Replaces these functions, if provided:

User FunctionvDSO
ClockGetTimeclock_gettime
ClockGetTimeOfDaygettimeofday
ClockGetResclock_getres
ClockGetTimetime

Examples

use tpom::*;
use std::time::SystemTime;

ClockController::overwrite(
    Some(|_| TimeSpec {
        seconds: 1,
        nanos: 1,
    }),
    None,
    None,
    None,
);
// Clock is frozen; all calls to time return the same values
let time_a = SystemTime::now();
let time_b = SystemTime::now();
assert_eq!(time_a, time_b);

// Restore clock; all calls to time return unique values
ClockController::restore();
let time_c = SystemTime::now();
let time_d = SystemTime::now();
assert_ne!(time_c, time_d);

Structs

ClockController
TimeSpec
Return type for ClockGetTime and ClockGetRes; maps to libc::timespec.
TimeVal
Return type for ClockGetTimeOfDay; maps to libc::timeval.

Type Definitions

ClockGetResCb
Considered infallible
ClockGetTimeCb
Considered infallible
ClockGetTimeOfDayCb
Considered infallible
TimeCb