IScheduler

Scheduler handles concurrent execution of all application tasks, assigning them to limited amount of worker fibers. Scheduler functionality can be split into 3 major blocks:

1. executing arbitrary ocean.task.Task using a worker fiber from a pool 2. keeping queue of tasks to execute in cases when all worker fibers are busy 3. allowing any task to suspend to allow event processing by epoll in a way that it will be automatically resumed by scheduler again when there are no more immediate pending events

interface IScheduler {

struct Configuration;

struct Stats;

struct SpecializedPoolStats;

EpollSelectDispatcher epoll();

void shutdown();

Stats getStats();

Optional!(SpecializedPoolStats) getSpecializedPoolStats(cstring name);

void schedule(Task task);

void queue(Task task);

void await(Task task, void delegate(Task) finished_dg);

typeof(TaskT.result) awaitResult(TaskT task);

bool awaitOrTimeout(Task task, uint micro_seconds);

void delayedResume(Task task);

void processEvents();

void eventLoop();

}

Members

Functions

await void await(Task task, void delegate(Task) finished_dg): Schedules the argument and suspends calling task until the argument finishes.
awaitOrTimeout bool awaitOrTimeout(Task task, uint micro_seconds): Similar to await but also has waiting timeout. Calling task will be resumed either if awaited task finished or timeout is hit, whichever happens first.
awaitResult typeof(TaskT.result) awaitResult(TaskT task): Convenience shortcut on top of await to await for a task and return some value type as a result.
delayedResume void delayedResume(Task task): Orders scheduler to resume given task unconditionally after current epoll cycle. Must be used instead of plain Task.resume from termination hooks of other tasks.
epoll EpollSelectDispatcher epoll(): Getter for scheduler epoll instance. Necessary for integration with ISelectClient utilities so that new select client can be registered.
eventLoop void eventLoop(): Starts pseudo-infinite event loop. Event loop will keep running as long as there is at least one event registered.
getSpecializedPoolStats Optional!(SpecializedPoolStats) getSpecializedPoolStats(cstring name)
getStats Stats getStats(): Provides load stats for the scheduler
processEvents void processEvents(): Suspends current fiber temporarily, allowing pending events to be processed. Current fiber will be resumed as soon as no immediate events are left.
queue void queue(Task task): Method used to queue the task for later execution.
schedule void schedule(Task task): Method used to execute new task.
shutdown void shutdown(): Forces early termination of all active tasks and shuts down event loop.

Structs

Configuration struct Configuration: Aggregation of various size limits used internally by scheduler. Instance of this struct is used as initScheduler argument.
SpecializedPoolStats struct SpecializedPoolStats: Usage stats of a single specialized task pool
Stats struct Stats: Aggregate of various statistics that indicate overall scheduler load and performance.

IScheduler

Members

Functions

Structs

Meta

Source