Copyright	(c) 2026 Jared Tobin
License	MIT
Maintainer	Jared Tobin <jared@ppad.tech>
Safe Haskell	None
Language	Haskell2010

Censor.Runner.Env

Contents

Environment snapshot

Description

Host-environment capture.

An Env is a point-in-time snapshot of the machine a censor run executed on: platform identity (OS, architecture, kernel release, CPU model, core count), the timing-relevant tuning knobs visible under Linux sysfs (cpufreq governor, turbo/boost state, SMT control, perf_event_paranoid), the load average, and a UTC timestamp.

Capture is best-effort: fields whose sources are absent on the host (e.g. the sysfs knobs on Darwin) are Nothing. Conditions affect the power of a run, not its validity — the paired, order-randomised design cancels common-mode drift — so the snapshot exists to make reports interpretable and provenanced, not to gate execution.

Synopsis

data Env = Env {
- envOs :: !String
- envArch :: !String
- envKernel :: !(Maybe String)
- envCpu :: !(Maybe String)
- envCores :: !Int
- envGovernor :: !(Maybe String)
- envBoost :: !(Maybe String)
- envSmt :: !(Maybe String)
- envParanoid :: !(Maybe String)
- envLoad :: !(Maybe (Double, Double, Double))
- envTime :: !(Maybe String)
}
captureEnv :: IO Env

Environment snapshot

data Env Source #

A host-environment snapshot, taken once at run start.

The Linux knob fields (envGovernor, envBoost, envSmt, envParanoid) hold the raw sysfs/procfs file contents; they are Nothing wherever the file does not exist (in particular, everywhere but Linux).

Constructors

Env

Fields

envOs :: !String
operating system, per System.Info.os.
envArch :: !String
architecture, per System.Info.arch.
envKernel :: !(Maybe String)
kernel release, per uname(2).
envCpu :: !(Maybe String)
CPU model string (Darwin sysctl, or the first model name row of Linux /proc/cpuinfo; absent on most aarch64 Linux kernels).
envCores :: !Int
logical core count.
envGovernor :: !(Maybe String)
Linux cpufreq scaling governor of cpu0.
envBoost :: !(Maybe String)
Linux turbo/boost state, recorded verbatim as key=value (boost=1 is boost-enabled; no_turbo=1 is boost-disabled) to avoid interpreting the two opposing conventions.
envSmt :: !(Maybe String)
Linux SMT control state (on / off / ...).
envParanoid :: !(Maybe String)
Linux kernel.perf_event_paranoid level.
envLoad :: !(Maybe (Double, Double, Double))
1/5/15-minute load averages at capture time.
envTime :: !(Maybe String)
capture time, UTC ISO-8601.

Instances

Instances details

Show Env Source #
Instance details Defined in Censor.Runner.Env Methods showsPrec :: Int -> Env -> ShowS # show :: Env -> String # showList :: [Env] -> ShowS #
Eq Env Source #
Instance details Defined in Censor.Runner.Env Methods (==) :: Env -> Env -> Bool # (/=) :: Env -> Env -> Bool #

captureEnv :: IO Env Source #

Snapshot the host environment. Cheap (a few syscalls and file reads); call once at run start.