golang.org/x/sys v0.0.0-20210510120138-977fb7262007: unix.Getpid

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 unix.Getpid in pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007
Demonstrate these symbols/APIs:
  - unix.Getpid

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:sha256:4ce3cc6d41d0323ee7597228bfbfedb54ca0e5a777a1a880d4734a7f29d1f30d","contract":["unix.Getpid returns a strictly positive integer representing the calling process ID","unix.Getpid returns the exact same process ID as os.Getpid within the calling process","unix.Getpid returns a consistent process ID across repeated sequential invocations","unix.Getpid returns the same process ID across concurrent goroutine invocations"],"goal":"verify unix.Getpid in pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007"],"schemaVersion":1,"symbols":["unix.Getpid"]},"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@v0.0.0-20210510120138-977fb7262007"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007","symbols":["unix.Getpid"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require golang.org/x/sys v0.0.0-20210510120138-977fb7262007

golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

package sample

import (
	"sync"

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

// CurrentPID returns the process ID of the calling process using unix.Getpid.
func CurrentPID() int {
	return unix.Getpid()
}

// CollectPIDsConcurrently invokes unix.Getpid across count goroutines and returns all observed PIDs.
func CollectPIDsConcurrently(count int) []int {
	if count <= 0 {
		return nil
	}
	results := make([]int, count)
	var wg sync.WaitGroup
	wg.Add(count)
	for i := 0; i < count; i++ {
		go func(idx int) {
			defer wg.Done()
			results[idx] = unix.Getpid()
		}(i)
	}
	wg.Wait()
	return results
}

{
  "schemaVersion": 1,
  "goal": "verify unix.Getpid in pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.0.0-20210510120138-977fb7262007"
  ],
  "symbols": [
    "unix.Getpid"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// Assertion 1: unix.Getpid returns a strictly positive integer representing the current process ID
	pid := unix.Getpid()
	if pid <= 0 {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Getpid returned non-positive PID: %d\n", pid)
		os.Exit(1)
	}

	// Assertion 2: unix.Getpid matches os.Getpid from the standard library
	stdPid := os.Getpid()
	if pid != stdPid {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Getpid (%d) != os.Getpid (%d)\n", pid, stdPid)
		os.Exit(1)
	}

	// Assertion 3: repeated sequential invocations of unix.Getpid return the same process ID
	for i := 0; i < 10; i++ {
		got := sample.CurrentPID()
		if got != pid {
			fmt.Fprintf(os.Stderr, "FAIL: sequential unix.Getpid call %d returned %d, expected %d\n", i, got, pid)
			os.Exit(1)
		}
	}

	// Assertion 4: concurrent invocations of unix.Getpid across goroutines return the same process ID
	pids := sample.CollectPIDsConcurrently(16)
	if len(pids) != 16 {
		fmt.Fprintf(os.Stderr, "FAIL: expected 16 concurrent PID results, got %d\n", len(pids))
		os.Exit(1)
	}
	for i, got := range pids {
		if got != pid {
			fmt.Fprintf(os.Stderr, "FAIL: goroutine %d unix.Getpid returned %d, expected %d\n", i, got, pid)
			os.Exit(1)
		}
	}

	fmt.Println("PASS: unix.Getpid contract verified")
}