Package com.ultikits.ultitools.utils

Class SerialRequestWorker

java.lang.Object

com.ultikits.ultitools.utils.SerialRequestWorker

final class SerialRequestWorker
extends Object

One dedicated worker thread for the file and server.properties requests of one connection (plan 22-21 fix round). Those handlers do blocking disk I/O -- a files.list of a directory with tens of thousands of entries takes seconds -- so they must not run on the connection's own thread, where every heartbeat, ack and other request would wait behind them.

Order. One thread and a FIFO queue: the wrapped requests are handled one at a time, in arrival order, so a files.write followed by a files.read of the same path still reads what was written.

Bounds. At most capacity requests wait; one more is answered at once with the generic error rate_limited (contract section 6) and never runs. The thread is a daemon named "UltiTools-CloudFiles" and ends when idle.

Failures. The router no longer surrounds a handler that runs here, so this worker answers as the router would: an InvalidFrameException becomes invalid_message (its code), any other runtime failure internal_error without the exception text. The reply goes out through the connection's channel.

Close. close() drops the requests that had not started (their connection is gone, so a reply could not reach the gateway, and an unanswered request is one the gateway reports as timed out -- never run twice) and lets the running one finish. Never waits for the thread.

Shutdown. A request the ShutdownGate covers (files.write, files.delete, properties.update) asks the gate again when it starts here, because it may have been queued before UltiTools#onDisable began: refused, it is answered with its shutting-down failure and never runs; let in, it keeps the gate's permit until it is answered, so onDisable waits for it before the action log closes.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static final int	DEFAULT_CAPACITY	How many file requests may wait behind the running one.
private final ThreadPoolExecutor	executor
private static final long	IDLE_SECONDS
private static final Logger	LOGGER
private final BlockingQueue<Runnable>	queue
private final ShutdownGate	shutdown
(package private) static final String	THREAD_NAME	The name of the worker thread.

Constructor Summary

Constructors

Constructor	Description
SerialRequestWorker(int capacity)	A worker whose requests are never refused for a shutdown.
SerialRequestWorker(int capacity, ShutdownGate shutdown)

Method Summary

Modifier and Type	Method	Description
(package private) void	close()	Drops the requests that had not started and stops the thread once the running one ends.
private static void	handle(CloudRequestHandler handler, CloudRequest request, CloudChannel channel)
private void	handleUnlessShuttingDown(CloudRequestHandler handler, CloudRequest request, CloudChannel channel)
private void	submit(CloudRequestHandler handler, CloudRequest request, CloudChannel channel)
(package private) CloudRequestHandler	wrap(CloudRequestHandler handler)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

THREAD_NAME

static final String THREAD_NAME

The name of the worker thread.

See Also:

• Constant Field Values

DEFAULT_CAPACITY

static final int DEFAULT_CAPACITY

How many file requests may wait behind the running one.

See Also:

• Constant Field Values

LOGGER

private static final Logger LOGGER

IDLE_SECONDS

private static final long IDLE_SECONDS

See Also:

• Constant Field Values

queue

private final BlockingQueue<Runnable> queue

executor

private final ThreadPoolExecutor executor

shutdown

private final ShutdownGate shutdown

Constructor Details

SerialRequestWorker

SerialRequestWorker(int capacity)

A worker whose requests are never refused for a shutdown.

Parameters:

capacity - how many requests may wait behind the running one; at least 1

SerialRequestWorker

SerialRequestWorker(int capacity,
 ShutdownGate shutdown)

Parameters:

capacity - how many requests may wait behind the running one; at least 1

shutdown - the shutdown gate a covered request asks when it starts

Method Details

wrap

CloudRequestHandler wrap(CloudRequestHandler handler)

Parameters:

handler - the blocking handler

Returns:

a handler that queues each request for this worker and returns at once

close

void close()

Drops the requests that had not started and stops the thread once the running one ends.

submit

private void submit(CloudRequestHandler handler,
 CloudRequest request,
 CloudChannel channel)

handleUnlessShuttingDown

private void handleUnlessShuttingDown(CloudRequestHandler handler,
 CloudRequest request,
 CloudChannel channel)

handle

private static void handle(CloudRequestHandler handler,
 CloudRequest request,
 CloudChannel channel)