golang.org/x/sys v0.14.0

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 pkg:golang/golang.org/x/sys@v0.14.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.14.0

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:ed7ac37c1b6a2c2a0e751c8f8ba2083453c03255b3701926dd3d46ee88ac65da","contract":["unix.Pipe2 creates a non-blocking pipe with close-on-exec flag transferring data between descriptors","unix.Ftruncate resizes an open file descriptor to the specified byte length","unix.ClockGettime retrieves current monotonic clock time with valid positive values","unix.Gettid returns a positive caller thread ID"],"goal":"verify pkg:golang/golang.org/x/sys@v0.14.0","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.14.0"],"schemaVersion":1},"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@v0.14.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.14.0","verifierAdapter":"golang@1"}

module example.com/sample

go 1.25.0

require golang.org/x/sys v0.14.0

golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

package main

import (
	"bytes"
	"fmt"
	"os"

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

// CreateNonBlockingPipe creates a unidirectional pipe with O_CLOEXEC and O_NONBLOCK flags.
func CreateNonBlockingPipe() ([2]int, error) {
	var fds [2]int
	if err := unix.Pipe2(fds[:], unix.O_CLOEXEC|unix.O_NONBLOCK); err != nil {
		return fds, fmt.Errorf("pipe2 failed: %w", err)
	}
	return fds, nil
}

// TruncateFile resizes an open file descriptor to the specified size in bytes.
func TruncateFile(fd int, size int64) error {
	if err := unix.Ftruncate(fd, size); err != nil {
		return fmt.Errorf("ftruncate failed: %w", err)
	}
	return nil
}

// GetMonotonicTime retrieves the current time from CLOCK_MONOTONIC.
func GetMonotonicTime() (unix.Timespec, error) {
	var ts unix.Timespec
	if err := unix.ClockGettime(unix.CLOCK_MONOTONIC, &ts); err != nil {
		return ts, fmt.Errorf("clock_gettime failed: %w", err)
	}
	return ts, nil
}

// GetThreadID retrieves the current thread ID using unix.Gettid.
func GetThreadID() int {
	return unix.Gettid()
}

func main() {
	// 1. Non-blocking pipe demonstration
	fds, err := CreateNonBlockingPipe()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error creating pipe: %v\n", err)
		os.Exit(1)
	}
	defer unix.Close(fds[0])
	defer unix.Close(fds[1])

	payload := []byte("golang.org/x/sys v0.14.0 demo")
	if _, err := unix.Write(fds[1], payload); err != nil {
		fmt.Fprintf(os.Stderr, "Error writing to pipe: %v\n", err)
		os.Exit(1)
	}

	buf := make([]byte, 64)
	n, err := unix.Read(fds[0], buf)
	if err != nil || !bytes.Equal(buf[:n], payload) {
		fmt.Fprintf(os.Stderr, "Error reading from pipe: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("Pipe transferred %d bytes: %s\n", n, string(buf[:n]))

	// 2. Ftruncate demonstration
	tmpFile, err := os.CreateTemp("", "sys_demo_*")
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error creating temp file: %v\n", err)
		os.Exit(1)
	}
	defer func() {
		tmpFile.Close()
		os.Remove(tmpFile.Name())
	}()

	fd := int(tmpFile.Fd())
	targetSize := int64(1024)
	if err := TruncateFile(fd, targetSize); err != nil {
		fmt.Fprintf(os.Stderr, "Error truncating file: %v\n", err)
		os.Exit(1)
	}

	var stat unix.Stat_t
	if err := unix.Fstat(fd, &stat); err != nil {
		fmt.Fprintf(os.Stderr, "Error stating file: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("File size after truncate: %d bytes\n", stat.Size)

	// 3. ClockGettime demonstration
	ts, err := GetMonotonicTime()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error getting monotonic time: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("Monotonic time: %d.%09d s\n", ts.Sec, ts.Nsec)

	// 4. Gettid demonstration
	tid := GetThreadID()
	fmt.Printf("Thread ID: %d\n", tid)
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/sys@v0.14.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.14.0"
  ]
}

package main

import (
	"bytes"
	"fmt"
	"os"

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

func main() {
	// Assertion 1: unix.Pipe2 creates a non-blocking pipe with close-on-exec flag transferring data between descriptors
	var fds [2]int
	if err := unix.Pipe2(fds[:], unix.O_CLOEXEC|unix.O_NONBLOCK); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Pipe2 failed: %v\n", err)
		os.Exit(1)
	}
	defer unix.Close(fds[0])
	defer unix.Close(fds[1])

	msg := []byte("sys-contract-pipe-test")
	n, err := unix.Write(fds[1], msg)
	if err != nil || n != len(msg) {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Write failed: n=%d, err=%v\n", n, err)
		os.Exit(1)
	}

	buf := make([]byte, 64)
	rn, err := unix.Read(fds[0], buf)
	if err != nil || rn != len(msg) || !bytes.Equal(buf[:rn], msg) {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Read failed: rn=%d, err=%v, data=%q\n", rn, err, string(buf[:rn]))
		os.Exit(1)
	}

	// Assertion 2: unix.Ftruncate resizes an open file descriptor to the specified byte length
	tmpFile, err := os.CreateTemp("", "contract_ftruncate_*")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: os.CreateTemp failed: %v\n", err)
		os.Exit(1)
	}
	defer func() {
		tmpFile.Close()
		os.Remove(tmpFile.Name())
	}()

	fd := int(tmpFile.Fd())
	targetSize := int64(2048)
	if err := unix.Ftruncate(fd, targetSize); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Ftruncate failed: %v\n", err)
		os.Exit(1)
	}

	var stat unix.Stat_t
	if err := unix.Fstat(fd, &stat); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Fstat failed: %v\n", err)
		os.Exit(1)
	}
	if stat.Size != targetSize {
		fmt.Fprintf(os.Stderr, "FAIL: unexpected file size: got %d, expected %d\n", stat.Size, targetSize)
		os.Exit(1)
	}

	// Assertion 3: unix.ClockGettime retrieves current monotonic clock time with valid positive values
	var ts unix.Timespec
	if err := unix.ClockGettime(unix.CLOCK_MONOTONIC, &ts); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: unix.ClockGettime failed: %v\n", err)
		os.Exit(1)
	}
	if ts.Sec < 0 || ts.Nsec < 0 || ts.Nsec >= 1000000000 {
		fmt.Fprintf(os.Stderr, "FAIL: invalid monotonic timespec: sec=%d, nsec=%d\n", ts.Sec, ts.Nsec)
		os.Exit(1)
	}

	// Assertion 4: unix.Gettid returns a positive caller thread ID
	tid := unix.Gettid()
	if tid <= 0 {
		fmt.Fprintf(os.Stderr, "FAIL: invalid thread ID from unix.Gettid: %d\n", tid)
		os.Exit(1)
	}

	fmt.Println("PASS: golang.org/x/sys contract passed")
}