Struct mmtk::scheduler::worker_monitor::WorkerMonitor

pub(crate) struct WorkerMonitor {
    sync: Mutex<WorkerMonitorSync>,
    workers_have_anything_to_do: Condvar,
}

A data structure for synchronizing workers with each other and with mutators.

Unlike GCWorkerShared, there is only one instance of WorkerMonitor.

• It allows workers to park and unpark.
• It allows mutators to notify workers to schedule a GC.

Fields

sync: Mutex<WorkerMonitorSync>

The synchronized part.

workers_have_anything_to_do: Condvar

Workers wait on this when idle. Notified if workers have things to do. That include:

• any work packets available, and
• any field in sync.goals.requests set to true.

Implementations

impl WorkerMonitor

pub fn new(worker_count: usize) -> Self

pub fn make_request(&self, goal: WorkerGoal)

Make a request. Can be called by a mutator to request the workers to work towards the given goal.

pub fn notify_work_available(&self, all: bool)

Wake up workers when more work packets are made available for workers, or a mutator has requested the GC workers to schedule a GC.

pub fn park_and_wait<F>( &self, ordinal: usize, on_last_parked: F ) -> Result<(), WorkerShouldExit>

where F: FnOnce(&mut WorkerGoals) -> LastParkedResult,

Park a worker and wait on the CondVar workers_have_anything_to_do.

If it is the last worker parked, on_last_parked will be called. The argument of on_last_parked is true if sync.gc_requested is true. The return value of on_last_parked will determine whether this worker and other workers will wake up or block waiting.

This function returns Ok(()) if the current worker should continue working, or Err(WorkerShouldExit) if the current worker should exit now.

pub fn on_all_workers_exited(&self)

Called when all workers have exited.