Package org.asynchttpclient.netty.channel

Class PerHostConnectionSemaphore

java.lang.Object

org.asynchttpclient.netty.channel.PerHostConnectionSemaphore

All Implemented Interfaces:

ConnectionSemaphore

Direct Known Subclasses:

CombinedConnectionSemaphore

public class PerHostConnectionSemaphore
extends Object
implements ConnectionSemaphore

Max per-host connections limiter.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	acquireTimeout
protected ConcurrentHashMap<Object,Semaphore>	freeChannelsPerHost
protected int	maxConnectionsPerHost
protected IOException	tooManyConnectionsPerHost

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.
protected Semaphore	getFreeConnectionsForHost(Object partitionKey)	Deprecated. does not participate in the reference-counted reservation bookkeeping that acquireChannelLock(Object, boolean)/releaseChannelLock(Object) rely on to prune idle host entries, so a permit acquired through the returned Semaphore should be released through the same instance rather than through releaseChannelLock(Object).
void	releaseChannelLock(Object partitionKey)

Methods inherited from class java.lang.Object

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

Field Detail

freeChannelsPerHost

protected final ConcurrentHashMap<Object,Semaphore> freeChannelsPerHost

maxConnectionsPerHost

protected final int maxConnectionsPerHost

tooManyConnectionsPerHost

protected final IOException tooManyConnectionsPerHost

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

getFreeConnectionsForHost

@Deprecated
protected Semaphore getFreeConnectionsForHost(Object partitionKey)

Deprecated.

does not participate in the reference-counted reservation bookkeeping that acquireChannelLock(Object, boolean)/releaseChannelLock(Object) rely on to prune idle host entries, so a permit acquired through the returned Semaphore should be released through the same instance rather than through releaseChannelLock(Object). Delegates to reserveFreeConnectionsForHost(Object) so the returned instance is always the map's current TrackedSemaphore for this key, kept only for binary compatibility.