Stdlib module threading/mutex.vitl

Overview

`threading/mutex.vitl` is a public stdlib surface inside the `threading` family. It should be read as one focused slice of the broader family responsibility: Thread, mutex, and pool-based concurrency helpers.

Purpose

This file should be chosen because of responsibility, not because its name “sounds close enough”. Inside the threading family, it carries one focused part of the contract and keeps that responsibility separate from neighboring concerns.

• A worker pool can process tasks in parallel while leaving task definition and result aggregation elsewhere.

Taxonomy

Think of this page as a generated encyclopedia entry rather than a hand-written tutorial. The goal is to show what kind of module this is, how dense it is, and what reading strategy makes sense before depending on it.

• Large algorithm surface: this file exposes many procedures and likely acts as a domain toolkit rather than a single thin wrapper.
• Owns domain vocabulary: the module declares data shapes in addition to executable helpers, so its types are part of the contract.
• Has tuning constants: part of the module behavior is controlled by named constants that document default precision, limits, or policy.
• Narrow dependency fan-in: a small set of imports suggests a focused collaboration surface.

Implementation profile

This profile is inferred directly from the source text. It does not replace reading the file, but it tells you quickly whether the module is mostly declarative, loop-heavy, branch-heavy, or organized around many small exits.

Top-level API inventory

Imported surfaces

• vitte/stdlib/threading/thread // Mutex

Position in family

This file is module 1 of 3 in the threading family when ordered by path. By procedure count it ranks 2, and by line count it ranks 2. Those ranks are useful as rough signals of breadth, not as quality judgments.

Declaration map

The declaration map turns raw source into a scan-friendly catalog. It is useful when the file is large enough that a reader wants to orient by kinds of surfaces first.

The table is exhaustive for top-level declarations of the selected kinds. This file declares 40 matching surfaces.

Representative signatures

These signatures are shown in source order so the page keeps the feel of a reference manual, not just a keyword cloud.

• form Mutex<T> { (line 7)
• proc mutex_new<T>(value: T) -> Mutex<T> { (line 18)
• proc mutex_recursive_new<T>(value: T) -> Mutex<T> { (line 33)
• proc mutex_lock<T>(mutex: Mutex<T>) -> bool { (line 48)
• proc mutex_try_lock<T>(mutex: Mutex<T>) -> bool { (line 72)
• proc mutex_lock_timeout<T>(mutex: Mutex<T>, timeout_ms: int) -> bool { (line 85)
• proc mutex_unlock<T>(mutex: Mutex<T>) -> bool { (line 101)
• proc mutex_get<T>(mutex: Mutex<T>) -> T { (line 123)
• proc mutex_set<T>(mutex: Mutex<T>, value: T) -> bool { (line 128)
• proc with_lock<T>(mutex: Mutex<T>, closure: proc) -> bool { (line 138)
• form RwLock<T> { (line 147)
• proc rwlock_new<T>(value: T) -> RwLock<T> { (line 158)
• proc rwlock_read_lock<T>(rwlock: RwLock<T>) -> bool { (line 173)
• proc rwlock_read_unlock<T>(rwlock: RwLock<T>) -> bool { (line 183)
• proc rwlock_write_lock<T>(rwlock: RwLock<T>) -> bool { (line 189)
• proc rwlock_write_unlock<T>(rwlock: RwLock<T>) -> bool { (line 204)
• proc rwlock_downgrade<T>(rwlock: RwLock<T>) -> bool { (line 211)
• form Condition { (line 224)

The list is intentionally capped here; the source file declares 38 matching signatures in total.

How to use this module

Start by reading the file as an ownership boundary. Ask three questions: what enters this module, what stable types or procedures it exports, and what adjacent module should stay outside of it.

1. Read space and top-level imports first so the ownership boundary of threading/mutex.vitl is explicit.
2. Scan constants before procedures; they often encode precision, limits, or policy assumptions that explain later behavior.
3. Read declared forms and picks before algorithms so the data vocabulary is stable in your head.
4. Traverse procedures in source order; the early helpers usually explain the naming and numeric conventions used later.
5. Only after that compare neighbor modules, because the right boundary choice matters more than memorizing one helper name.

User example

This example is generated from the actual stdlib module surface. Its job is not to be the smallest snippet possible; its job is to show a realistic consumer-shaped file that exercises the module and mirrors the language keywords the module itself relies on.

space demo/threading_mutex
use vitte/stdlib/threading/mutex
const SAMPLE_RETRIES: int = 1
const INITIAL_VALUE: int = 0
form CounterReport {
  ok: bool,
  value: int
}
proc run_example() -> CounterReport {
  let guard = mutex_new<int>(INITIAL_VALUE)
  let ready: bool = mutex_lock<int>(guard)
  let wrote: bool = mutex_set<int>(guard, 1)
  let value: int = mutex_get<int>(guard)
  let released: bool = mutex_unlock<int>(guard)
  let retries: int = 0
  while retries < SAMPLE_RETRIES {
    set retries = retries + 1
  }
  for worker in [1] {
    let _seen: int = worker
  }
  let ok: bool = ready
  if not ok {
    give CounterReport { ok: false, value: value }
  } else {
    give CounterReport { ok: true, value: value }
  }
}

Keyword coverage

This table makes the “all keywords of the module” requirement auditable. It compares the detected Vitte keywords in the source file with the generated consumer example above.

The generated snippet exercises every detected Vitte keyword used by this module.

Source shape

space vitte/stdlib/threading/mutex
use vitte/stdlib/threading/thread
// Mutex - Mutual Exclusion Lock
form Mutex<T> {
  id: int,
  data: T,
  locked: bool,
  owner_thread: int,
  lock_count: int,          // For recursive mutex
  waiters: [int],           // Waiting thread IDs

The excerpt is not meant to replace the file. It exists to make the module recognizable at first glance, the same way a Wikipedia infobox helps the reader orient before reading the whole article.

Source landmarks

Large files are easier to retain when they have visible landmarks. When the source contains explicit section banners, they are surfaced here; otherwise the first major declarations are used as anchors.

• Line 1: space vitte/stdlib/threading/mutex
• Line 3: use vitte/stdlib/threading/thread
• Line 7: form Mutex<T> {
• Line 18: proc mutex_new<T>(value: T) -> Mutex<T> {
• Line 33: proc mutex_recursive_new<T>(value: T) -> Mutex<T> {
• Line 48: proc mutex_lock<T>(mutex: Mutex<T>) -> bool {
• Line 72: proc mutex_try_lock<T>(mutex: Mutex<T>) -> bool {
• Line 85: proc mutex_lock_timeout<T>(mutex: Mutex<T>, timeout_ms: int) -> bool {

Source organization

When a file carries its own internal chaptering, those chapters usually reveal the intended reading order better than a flat symbol list. This section reconstructs that organization from the source itself.

Complete API catalog

This catalog is the exhaustive file-level index for the module. It is intentionally closer to a generated encyclopedia appendix than to a tutorial summary.

Constants

Data surfaces

Procedures

Imports

Integration boundaries

Within threading, this file should remain focused. If a future helper changes the host boundary, scheduling boundary, or data-shape boundary, it probably belongs in a neighbor module instead of being added here by convenience.

• Family responsibility: Thread, mutex, and pool-based concurrency helpers.
• Family architecture role: Use `threading` when the program needs explicit concurrency coordination rather than single-threaded transformation.

Composition guidance

Choose this module when

• Choose threading/mutex.vitl when the main question is owned by this module rather than by transport, storage, orchestration, or user-interface code.
• A worker pool can process tasks in parallel while leaving task definition and result aggregation elsewhere.

Pause before extending it when

• Avoid extending this file when the new helper mostly changes the boundary to host I/O, runtime coordination, or foreign integration instead of staying inside threading.
• Check nearby modules such as threading/thread.vitl, threading/threadpool.vitl before adding convenience wrappers here.

Relationship table

This table keeps the page closer to a real encyclopedia entry: a module is easier to understand when compared with its nearest alternatives in the same family.

Neighbor modules

• threading/thread.vitl
• threading/threadpool.vitl