Struct Scheduler

pub struct Scheduler { /* private fields */ }

A scheduler for running Lua threads and async tasks.

Implementations

impl Scheduler

pub fn new(lua: Lua) -> Scheduler

Creates a new scheduler for the given Lua state.

This scheduler will have a default error callback that prints errors to stderr.

Panics

Panics if the given Lua state already has a scheduler attached to it.

pub fn status(&self) -> Status

Returns the current status of this scheduler.

pub fn set_error_callback(&self, callback: impl Fn(LuaError) + Send + 'static)

Sets the error callback for this scheduler.

This callback will be called whenever a Lua thread errors.

Overwrites any previous error callback.

Panics

Panics if the scheduler is currently running.

pub fn remove_error_callback(&self)

Clears the error callback for this scheduler.

This will remove any current error callback, including default(s).

Panics

Panics if the scheduler is currently running.

pub fn get_exit_code(&self) -> Option<u8>

Gets the exit code for this scheduler, if one has been set.

pub fn set_exit_code(&self, code: u8)

Sets the exit code for this scheduler.

This will cause Scheduler::run to exit immediately.

pub fn push_thread_front( &self, thread: impl IntoLuaThread, args: impl IntoLuaMulti, ) -> LuaResult<ThreadId>

Spawns a chunk / function / thread onto the scheduler queue.

Threads are guaranteed to be resumed in the order that they were pushed to the queue.

Returns

Returns a ThreadId that can be used to retrieve the result of the thread.

Note that the result may not be available until Scheduler::run completes.

Errors

Errors when out of memory.

pub fn push_thread_back( &self, thread: impl IntoLuaThread, args: impl IntoLuaMulti, ) -> LuaResult<ThreadId>

Defers a chunk / function / thread onto the scheduler queue.

Deferred threads are guaranteed to run after all spawned threads either yield or complete.

Threads are guaranteed to be resumed in the order that they were pushed to the queue.

Returns

Returns a ThreadId that can be used to retrieve the result of the thread.

Note that the result may not be available until Scheduler::run completes.

Errors

Errors when out of memory.

pub fn get_thread_result( &self, id: ThreadId, ) -> Option<LuaResult<LuaMultiValue>>

Gets the tracked result for the LuaThread with the given ThreadId.

Depending on the current Scheduler::status, this method will return:

• Status::NotStarted: returns None.
• Status::Running: may return Some(Ok(v)) or Some(Err(e)), but it is not guaranteed.
• Status::Completed: returns Some(Ok(v)) or Some(Err(e)).

Note that this method also takes the value out of the scheduler and stops tracking the given thread, so it may only be called once.

Any subsequent calls after this method returns Some will return None.

pub async fn wait_for_thread(&self, id: ThreadId)

Waits for the LuaThread with the given ThreadId to complete.

This will return instantly if the thread has already completed.

pub async fn run(&self)

Runs the scheduler until all Lua threads have completed.

Note that the given Lua state must be the same one that was used to create this scheduler, otherwise this method will panic.

Panics

Panics if the given Lua state already has a scheduler attached to it.

Trait Implementations

impl Clone for Scheduler

fn clone(&self) -> Scheduler

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Drop for Scheduler

fn drop(&mut self)

Executes the destructor for this type.