Crate web_thread

TODO:

• Re-factor builder implementation.
• Add MessageSend macro.
• Add WorkletBuilder (or use Builder).
• Wrap MessageChannel into something safe.
• Consider passing message into Builder.
• Add README.
• Consider moving some APIs into web-thread-core/primitives.

Things to note:

• Will fail on import when used with the no-modules target.
• Blocking is not recommended, e.g. blocks events.
• Audio worklets are very limited, e.g. should not do any allocation.
• Spawning happens on the “main” thread, e.g. if blocked nothing will spawn (affects some browsers only).
• Calling any functions from a thread not spawned by web-thread will cause issues.

Browser bugs:

• Browsers don’t support TextEncoder/TextDecoder in audio worklets:
  • Chrome: ?
  • Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1826432
  • Safari: ?
• Firefox doesn’t support module service workers: https://bugzilla.mozilla.org/show_bug.cgi?id=1360870.
• Browsers don’t support blocking in shared workers:
  • Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1359745
  • Safari: ?
• Spec doesn’t allow cross-origin isolation in shared and service workers: https://github.com/w3c/ServiceWorker/pull/1545.
• Browsers don’t support spawning and blocking afterwards (e.g. spawn(..).join()):
  • Chrome:
    • Spawning: https://issues.chromium.org/issues/40633395
    • postMessage(): https://issues.chromium.org/issues/40687798
  • Safari: ?
• Browsers don’t properly shutdown audio worklet when state is closed:
  • Chrome: https://issues.chromium.org/issues/40072701
  • Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1878516
  • Safari: ?
• Headless browsers seem to have some issues when spawning too many threads:
  • Firefox: ?
  • Safari: ?
• Headless Firefox can’t run AudioContext without a real audio device: https://bugzilla.mozilla.org/show_bug.cgi?id=1881904.
• Chrome fails to send WebAssembly.Module over AudioWorkletNode.port: https://issues.chromium.org/issues/40855462.

Modules

• webWeb
  Platform-specific extensions for web-thread on the Web platform.

Structs

• AccessError
  An error returned by LocalKey::try_with.
• Builder
  See std::thread::Builder.
• JoinHandle
  See std::thread::JoinHandle.
• LocalKey
  A thread local storage key which owns its contents.
• Scope
  See std::thread::Scope.
• ScopedJoinHandle
  See std::thread::ScopedJoinHandle.
• Thread
  See std::thread::Thread.
• ThreadId
  See std::thread::ThreadId.

Functions

• available_parallelism
  See std::thread::available_parallelism().
• current
  See std::thread::current().
• panicking
  Determines whether the current thread is unwinding because of panic.
• park
  See std::thread::park().
• park_timeout
  See std::thread::park_timeout().
• park_timeout_msDeprecated
  See std::thread::park_timeout_ms().
• scope
  See std::thread::scope().
• sleep
  See std::thread::sleep().
• sleep_msDeprecated
  See std::thread::sleep_ms().
• spawn
  See std::thread::spawn().
• yield_now
  See std::thread::yield_now().
• sleep_untilExperimental
  Puts the current thread to sleep until the specified deadline has passed.

Type Aliases

• Result
  A specialized Result type for threads.