next.js

4674a435 - Turbopack: Make the priority_runner testcase deterministic (#88651)

Turbopack: Make the priority_runner testcase deterministic (#88651) # What Fixes the `test_mixed_cpu_bound_and_waiting_tasks` to avoid flakes. # Why The `test_mixed_cpu_bound_and_waiting_tasks` was non-deterministic and relied on thread scheduling order. The previous test relied on timing-based synchronization using sleep() calls with varying durations to simulate CPU-bound and async work. This approach was inherently flaky because: 1. Thread scheduling is non-deterministic - a task sleeping for 10ms might complete before one sleeping for 5ms depending on OS scheduler behaviour 2. The assertions depended on specific completion ordering that wasn't guaranteed by the timing 3. Test behaviour could vary based on system load, available cores, and Tokio runtime scheduling # How he new approach uses std::sync::Barrier pairs (start, finish) for each task, giving the test explicit control over when tasks can proceed. Because this is a priority-ordered system, we know which barriers should be available at any given time and can release them. If the given task is not current waiting on its own corresponding barrier, the test will fail.