Package org.asynchttpclient.netty.channel

Class MaxConnectionSemaphore

java.lang.Object

org.asynchttpclient.netty.channel.MaxConnectionSemaphore

All Implemented Interfaces:

ConnectionSemaphore

public class MaxConnectionSemaphore
extends Object
implements ConnectionSemaphore

Max connections limiter.

Author:

Stepan Koltsov, Alex Maltinsky

Field Summary

Fields

Modifier and Type	Field	Description
protected int	acquireTimeout
protected Semaphore	freeChannels
protected IOException	tooManyConnections

Method Summary

Modifier and Type	Method	Description
void	acquireChannelLock(Object partitionKey)
void	acquireChannelLock(Object partitionKey, boolean nonBlocking)	Acquires a connection permit for partitionKey, optionally without blocking.
void	releaseChannelLock(Object partitionKey)

Methods inherited from class java.lang.Object

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

Field Detail

freeChannels

protected final Semaphore freeChannels

tooManyConnections

protected final IOException tooManyConnections

acquireTimeout

protected final int acquireTimeout

Method Detail

acquireChannelLock

public void acquireChannelLock(Object partitionKey)
                        throws IOException

Specified by:

acquireChannelLock in interface ConnectionSemaphore

Throws:

IOException

acquireChannelLock

public void acquireChannelLock(Object partitionKey,
                               boolean nonBlocking)
                        throws IOException

Description copied from interface: ConnectionSemaphore

Acquires a connection permit for partitionKey, optionally without blocking.

When nonBlocking is true a permit must be taken without waiting — the too-many-connections exception is thrown immediately if none is free. This is used when the caller runs on a Netty event-loop thread (a redirect / 401 / 407 / retry replay re-enters the send path on the event loop), where waiting for the configured acquire timeout would freeze the loop and stall every other connection it serves. When false this behaves exactly like ConnectionSemaphore.acquireChannelLock(Object).

The default implementation ignores the hint and delegates to the blocking ConnectionSemaphore.acquireChannelLock(Object), preserving the behaviour of custom implementations; the built-in limiters override it to honour nonBlocking.

Specified by:

acquireChannelLock in interface ConnectionSemaphore

Parameters:

partitionKey - the per-host partition key the permit is scoped to

nonBlocking - true to fail fast instead of waiting for a permit

Throws:

IOException - if no permit could be acquired

releaseChannelLock

public void releaseChannelLock(Object partitionKey)

Specified by:

releaseChannelLock in interface ConnectionSemaphore