ecmascript/jobs

Microtask queue implementation for Promise and async operation scheduling, conforming to ECMAScript microtask semantics. Primary Language: C++

Design

Implements the microtask queue for asynchronous operations:

  Promise.then() / queueMicrotask()
       │
       ▼
  MicroJobQueue::EnqueueMicrotask()
       │
       ├──▶ PendingJob (job wrapper)
       │     ├── Callback function
       │     ├── Arguments
       │     └── Context
       │
       ▼
  MicroJobQueue::Execute() (called at check points)
       │
       └──▶ Execute all queued jobs in FIFO order

Key abstractions:

• MicroJobQueue — Per-VM microtask queue, manages job lifecycle
• PendingJob — Job container holding callback and arguments
• HiTraceScope — Performance tracing integration

Reference Source

• arkcompiler/ets_runtime/ecmascript/jobs/micro_job_queue.h (1-100行) - Microtask queue interface

Key Files

File	Role
micro_job_queue.h/.cpp	Microtask queue implementation
pending_job.h	Job container definition
hitrace_scope.h/.cpp	Performance tracing integration

Building

Standalone repo (from repo root ../../):

python ark.py x64.debug

Full OHOS tree:

./build.sh --product-name <product-name> --build-target ark_js_host_linux_tools_packages

Tests

Standalone repo (from repo root ../../):

python ark.py x64.debug unittest   # includes jobs tests

Full OHOS tree:

./build.sh --product-name <product-name> --build-target ecmascript/jobs/tests:host_unittest

Boundaries

• Microtasks are per-VM; do not share queues across VMs.
• Jobs execute synchronously during Execute(); no async execution here.
• Integration with Promise and async/await is in builtins/.