go.uber.org/atomic v1.6.0

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/go.uber.org/atomic@v1.6.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.uber.org/atomic@v1.6.0

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:sha256:08303c6a42809de415757c723427f56e6df573d216e05bfdda6cb4fb568a46ca","contract":["Int64 Add, Sub, Inc, and Dec atomically modify numeric values and return the updated result","Int64 CAS atomically compares and swaps value only when current value matches expected old value","Bool Store, Load, and Swap atomically update and retrieve boolean state","Bool Toggle atomically inverts the boolean value and returns the previous value","String Store and Load provide atomic thread-safe storage for string values","Float64 Add and Sub atomically update floating point values"],"goal":"verify pkg:golang/go.uber.org/atomic@v1.6.0","kind":"HOW","packages":["pkg:golang/go.uber.org/atomic@v1.6.0"],"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/go.uber.org/atomic@v1.6.0"],"schemaVersion":1,"subject":"pkg:golang/go.uber.org/atomic@v1.6.0","verifierAdapter":"golang@1"}

module sample

go 1.26.6

require go.uber.org/atomic v1.6.0

github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
go.uber.org/atomic v1.6.0 h1:Ezj3JGmsOnG1MoRWQkPBsKLe9DwWD9QeXzTRzzldNVk=
go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/lint v0.0.0-20190930215403-16217165b5de h1:5hukYrvBGR8/eNkX5mdUezrA6JiaEZDtJb9Ei+1LlBs=
golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
golang.org/x/tools v0.0.0-20191029041327-9cc4af7d6b2c h1:IGkKhmfzcztjm6gYkykvu/NiS8kaqbCWAEWWAyf8J5U=
golang.org/x/tools v0.0.0-20191029041327-9cc4af7d6b2c/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

package main

import (
	"fmt"
	"sync"
	"time"

	"go.uber.org/atomic"
)

// TaskMetrics tracks task execution metrics concurrently.
type TaskMetrics struct {
	running   *atomic.Bool
	completed *atomic.Int64
	failures  *atomic.Int64
	status    *atomic.String
	duration  *atomic.Duration
}

// NewTaskMetrics initializes a new metrics tracker.
func NewTaskMetrics() *TaskMetrics {
	return &TaskMetrics{
		running:   atomic.NewBool(true),
		completed: atomic.NewInt64(0),
		failures:  atomic.NewInt64(0),
		status:    atomic.NewString("running"),
		duration:  atomic.NewDuration(0),
	}
}

// RecordSuccess atomically increments completed tasks.
func (m *TaskMetrics) RecordSuccess() int64 {
	return m.completed.Inc()
}

// RecordFailure atomically increments failure count.
func (m *TaskMetrics) RecordFailure() int64 {
	return m.failures.Inc()
}

// Stop atomically marks the metrics tracker as stopped and records elapsed duration.
func (m *TaskMetrics) Stop(elapsed time.Duration) bool {
	m.duration.Store(elapsed)
	m.status.Store("stopped")
	return m.running.CAS(true, false)
}

// IsRunning reports whether the tracker is currently running.
func (m *TaskMetrics) IsRunning() bool {
	return m.running.Load()
}

func main() {
	start := time.Now()
	metrics := NewTaskMetrics()
	var wg sync.WaitGroup

	for i := 0; i < 5; i++ {
		wg.Add(1)
		go func(workerID int) {
			defer wg.Done()
			if metrics.IsRunning() {
				metrics.RecordSuccess()
			}
		}(i)
	}

	wg.Wait()
	metrics.Stop(time.Since(start))

	fmt.Printf("Status: %s, Completed: %d, Running: %t, Duration: %v\n",
		metrics.status.Load(),
		metrics.completed.Load(),
		metrics.IsRunning(),
		metrics.duration.Load(),
	)
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/go.uber.org/atomic@v1.6.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.uber.org/atomic@v1.6.0"
  ]
}

package main

import (
	"fmt"
	"os"

	"go.uber.org/atomic"
)

func main() {
	// Assertion 1: Int64 Add, Sub, Inc, and Dec atomically modify numeric values and return the updated result
	{
		n := atomic.NewInt64(10)
		if got := n.Add(5); got != 15 || n.Load() != 15 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: Add expected 15, got %d\n", got)
			os.Exit(1)
		}
		if got := n.Sub(3); got != 12 || n.Load() != 12 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: Sub expected 12, got %d\n", got)
			os.Exit(1)
		}
		if got := n.Inc(); got != 13 || n.Load() != 13 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: Inc expected 13, got %d\n", got)
			os.Exit(1)
		}
		if got := n.Dec(); got != 12 || n.Load() != 12 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: Dec expected 12, got %d\n", got)
			os.Exit(1)
		}
	}

	// Assertion 2: Int64 CAS atomically compares and swaps value only when current value matches expected old value
	{
		n := atomic.NewInt64(100)
		if !n.CAS(100, 200) || n.Load() != 200 {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: CAS should succeed when old value matches\n")
			os.Exit(1)
		}
		if n.CAS(100, 300) || n.Load() != 200 {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: CAS should return false when old value does not match\n")
			os.Exit(1)
		}
	}

	// Assertion 3: Bool Store, Load, and Swap atomically update and retrieve boolean state
	{
		b := atomic.NewBool(false)
		if b.Load() != false {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: initial Load expected false\n")
			os.Exit(1)
		}
		b.Store(true)
		if b.Load() != true {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: Load after Store expected true\n")
			os.Exit(1)
		}
		old := b.Swap(false)
		if old != true || b.Load() != false {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: Swap expected old value true and new value false\n")
			os.Exit(1)
		}
	}

	// Assertion 4: Bool Toggle atomically inverts the boolean value and returns the previous value
	{
		b := atomic.NewBool(false)
		prev1 := b.Toggle()
		if prev1 != false || b.Load() != true {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: Toggle on false expected prev false and current true\n")
			os.Exit(1)
		}
		prev2 := b.Toggle()
		if prev2 != true || b.Load() != false {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: Toggle on true expected prev true and current false\n")
			os.Exit(1)
		}
	}

	// Assertion 5: String Store and Load provide atomic thread-safe storage for string values
	{
		s := atomic.NewString("initial")
		if got := s.Load(); got != "initial" {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: initial Load expected 'initial', got %q\n", got)
			os.Exit(1)
		}
		s.Store("updated")
		if got := s.Load(); got != "updated" {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: Load after Store expected 'updated', got %q\n", got)
			os.Exit(1)
		}
	}

	// Assertion 6: Float64 Add and Sub atomically update floating point values
	{
		f := atomic.NewFloat64(10.5)
		if got := f.Add(2.5); got != 13.0 || f.Load() != 13.0 {
			fmt.Fprintf(os.Stderr, "assertion 6 failed: Add expected 13.0, got %f\n", got)
			os.Exit(1)
		}
		if got := f.Sub(1.5); got != 11.5 || f.Load() != 11.5 {
			fmt.Fprintf(os.Stderr, "assertion 6 failed: Sub expected 11.5, got %f\n", got)
			os.Exit(1)
		}
	}

	fmt.Println("All contract assertions passed successfully.")
}