golang.org/x/sys v0.19.0: unix.Timespec

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify golang.org/x/sys/unix.Timespec in pkg:golang/golang.org/x/sys@v0.19.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.19.0
Demonstrate these symbols/APIs:
  - golang.org/x/sys/unix.Timespec

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:0131f2362374fc0aed1d381b417f1fef13b7b00500b0f561a833876644fda304","contract":["NsecToTimespec converts nanoseconds into Sec and Nsec components","TimespecToNsec computes total nanoseconds from Timespec","Timespec Nano method returns total duration in nanoseconds","Timespec Unix method returns split second and nanosecond components","TimeToTimespec converts standard time.Time to Timespec representation","ClockGettime populates Timespec with non-zero system time"],"goal":"verify golang.org/x/sys/unix.Timespec in pkg:golang/golang.org/x/sys@v0.19.0","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.19.0"],"schemaVersion":1,"symbols":["golang.org/x/sys/unix.Timespec"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/sys@v0.19.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.19.0","symbols":["golang.org/x/sys/unix.Timespec"],"verifierAdapter":"golang@1"}

module sample

go 1.24.0

require golang.org/x/sys v0.19.0

golang.org/x/sys v0.19.0 h1:q5f1RH2jigJ1MoAWp2KTp3gm5zAGFUTarQZ5U386+4o=
golang.org/x/sys v0.19.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

package main

import (
	"fmt"
	"os"
	"time"

	"golang.org/x/sys/unix"
)

// MeasureInterval demonstrates calculating elapsed duration using unix.Timespec.
func MeasureInterval() (unix.Timespec, error) {
	var start, end unix.Timespec
	if err := unix.ClockGettime(unix.CLOCK_MONOTONIC, &start); err != nil {
		return unix.Timespec{}, fmt.Errorf("clock_gettime start failed: %w", err)
	}

	time.Sleep(10 * time.Millisecond)

	if err := unix.ClockGettime(unix.CLOCK_MONOTONIC, &end); err != nil {
		return unix.Timespec{}, fmt.Errorf("clock_gettime end failed: %w", err)
	}

	elapsedNsec := end.Nano() - start.Nano()
	return unix.NsecToTimespec(elapsedNsec), nil
}

func main() {
	elapsed, err := MeasureInterval()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}

	sec, nsec := elapsed.Unix()
	fmt.Printf("Elapsed: %d seconds, %d nanoseconds\n", sec, nsec)
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/sys/unix.Timespec in pkg:golang/golang.org/x/sys@v0.19.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.19.0"
  ],
  "symbols": [
    "golang.org/x/sys/unix.Timespec"
  ]
}

package main

import (
	"fmt"
	"os"
	"time"

	"golang.org/x/sys/unix"
)

func main() {
	// 1. NsecToTimespec converts nanoseconds into Sec and Nsec components
	{
		const totalNsec = int64(2_750_000_000)
		ts := unix.NsecToTimespec(totalNsec)
		if ts.Sec != 2 || ts.Nsec != 750_000_000 {
			fmt.Fprintf(os.Stderr, "FAIL: expected Sec=2, Nsec=750000000, got Sec=%d, Nsec=%d\n", ts.Sec, ts.Nsec)
			os.Exit(1)
		}
	}

	// 2. TimespecToNsec computes total nanoseconds from Timespec
	{
		ts := unix.Timespec{Sec: 3, Nsec: 125_000_000}
		totalNsec := unix.TimespecToNsec(ts)
		if totalNsec != 3_125_000_000 {
			fmt.Fprintf(os.Stderr, "FAIL: expected 3125000000 nsec, got %d\n", totalNsec)
			os.Exit(1)
		}
	}

	// 3. Timespec Nano method returns total duration in nanoseconds
	{
		ts := unix.Timespec{Sec: 5, Nsec: 500_000_000}
		if nano := ts.Nano(); nano != 5_500_000_000 {
			fmt.Fprintf(os.Stderr, "FAIL: expected Nano() to return 5500000000, got %d\n", nano)
			os.Exit(1)
		}
	}

	// 4. Timespec Unix method returns split second and nanosecond components
	{
		ts := unix.Timespec{Sec: 10, Nsec: 999_999}
		sec, nsec := ts.Unix()
		if sec != 10 || nsec != 999_999 {
			fmt.Fprintf(os.Stderr, "FAIL: expected sec=10, nsec=999999, got sec=%d, nsec=%d\n", sec, nsec)
			os.Exit(1)
		}
	}

	// 5. TimeToTimespec converts standard time.Time to Timespec representation
	{
		refTime := time.Unix(1700000000, 456789000)
		ts, err := unix.TimeToTimespec(refTime)
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: TimeToTimespec returned unexpected error: %v\n", err)
			os.Exit(1)
		}
		if ts.Sec != 1700000000 || ts.Nsec != 456789000 {
			fmt.Fprintf(os.Stderr, "FAIL: unexpected Timespec values from TimeToTimespec: %+v\n", ts)
			os.Exit(1)
		}
	}

	// 6. ClockGettime populates Timespec with non-zero system time
	{
		var ts unix.Timespec
		if err := unix.ClockGettime(unix.CLOCK_REALTIME, &ts); err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: ClockGettime(CLOCK_REALTIME) failed: %v\n", err)
			os.Exit(1)
		}
		if ts.Sec <= 0 {
			fmt.Fprintf(os.Stderr, "FAIL: ClockGettime returned non-positive seconds: %d\n", ts.Sec)
			os.Exit(1)
		}
	}

	fmt.Println("PASS: all contract assertions passed")
}