+ protected messageListener (message: MessageValue<Data, Data>): void {
+ if (message.workerId === this.id) {
+ if (message.ready != null) {
+ // Startup message received
+ this.workerReady()
+ } else if (message.statistics != null) {
+ // Statistics message received
+ this.statistics = message.statistics
+ } else if (message.checkAlive != null) {
+ // Check alive message received
+ message.checkAlive ? this.startCheckAlive() : this.stopCheckAlive()
+ } else if (message.id != null && message.data != null) {
+ // Task message received
+ this.run(message)
+ } else if (message.kill === true) {
+ // Kill message received
+ this.stopCheckAlive()
+ this.emitDestroy()
+ }
+ }
+ }
+
+ /**
+ * Notifies the main worker that this worker is ready to process tasks.
+ */
+ protected workerReady (): void {
+ !this.isMain && this.sendToMainWorker({ ready: true, workerId: this.id })
+ }
+
+ /**
+ * Starts the worker alive check interval.
+ */
+ private startCheckAlive (): void {
+ this.lastTaskTimestamp = performance.now()
+ this.aliveInterval = setInterval(
+ this.checkAlive.bind(this),
+ (this.opts.maxInactiveTime ?? DEFAULT_MAX_INACTIVE_TIME) / 2
+ )
+ this.checkAlive.bind(this)()
+ }
+
+ /**
+ * Stops the worker alive check interval.
+ */
+ private stopCheckAlive (): void {
+ this.aliveInterval != null && clearInterval(this.aliveInterval)
+ }
+
+ /**
+ * Checks if the worker should be terminated, because its living too long.
+ */
+ private checkAlive (): void {