NewConfig returns Config instance with default configuration values.

Run creates as many child workers as specified by *Config and start them.

WithReporter creates and returns WorkerOption to set preferred Reporter implementation.

ErrEnqueueAfterWorkerShutdown is returned when job is given after worker context cancellation.

ErrQueueOverflow is returned when job is given, but all workers are busy and queue is full.

Config contains some configuration variables.

Stats represents a group of statistical data.

Reporter is an interface to report statistics such as queue length to outer service.

Worker is an interface that all Worker implementation must satisfy.

WorkerOption defines function that worker's functional option must satisfy.