Package org.eclipse.aether.named.providers

Class FileLockNamedLockFactory

java.lang.Object

org.eclipse.aether.named.support.NamedLockFactorySupport

org.eclipse.aether.named.providers.FileLockNamedLockFactory

All Implemented Interfaces:

NamedLockFactory

@Singleton
@Named("file-lock")
public class FileLockNamedLockFactory
extends NamedLockFactorySupport

Named locks factory of FileLockNamedLocks. This is a bit of special implementation, as it expects locks names to be proper URI string representations (use file: protocol for default file system).

Since:

1.7.3

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	NAME
static java.lang.String	SYSTEM_PROP_ATTEMPTS	Tweak: on Windows, the presence of StandardOpenOption#DELETE_ON_CLOSE causes concurrency issues.
static java.lang.String	SYSTEM_PROP_DELETE_LOCK_FILES	Tweak: on Windows, the presence of StandardOpenOption#DELETE_ON_CLOSE causes concurrency issues.
static java.lang.String	SYSTEM_PROP_MAX_CACHED_CHANNELS	Maximum number of idle (not currently locked) FileChannels to keep open for reuse.
static java.lang.String	SYSTEM_PROP_SLEEP_MILLIS	Tweak: When SYSTEM_PROP_ATTEMPTS used, the amount of milliseconds to sleep between subsequent retries.

Fields inherited from class org.eclipse.aether.named.support.NamedLockFactorySupport

logger, SYSTEM_PROP_DIAGNOSTIC_ENABLED

Constructor Summary

Constructors

Constructor	Description
FileLockNamedLockFactory()

Method Summary

Modifier and Type	Method	Description
protected NamedLockSupport	createLock(NamedLockKey key)	Implementations shall create and return NamedLockSupport for given name, this method must never return null.
protected void	destroyLock(NamedLock namedLock)	Implementation may override this (empty) method to perform some sort of implementation specific cleanup for given lock name.
protected void	doShutdown()

Methods inherited from class org.eclipse.aether.named.support.NamedLockFactorySupport

closeLock, doGetLock, getLock, getLockAndRefTrack, isDiagnosticEnabled, onFailure, shutdown

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.aether.named.NamedLockFactory

getLock

Field Detail

NAME

public static final java.lang.String NAME

See Also:

Constant Field Values

SYSTEM_PROP_DELETE_LOCK_FILES

public static final java.lang.String SYSTEM_PROP_DELETE_LOCK_FILES

Tweak: on Windows, the presence of StandardOpenOption#DELETE_ON_CLOSE causes concurrency issues. This flag allows to have it removed from effective flags, at the cost that lockfile directory becomes crowded with 0 byte sized lock files that are never cleaned up. Default value is true on non-Windows OS. See JDK-8252883 for Windows related bug. Users on Windows can still force "delete on close" by explicitly setting this property to true.

See Also:

JDK-8252883, Constant Field Values

SYSTEM_PROP_ATTEMPTS

public static final java.lang.String SYSTEM_PROP_ATTEMPTS

Tweak: on Windows, the presence of StandardOpenOption#DELETE_ON_CLOSE causes concurrency issues. This flag allows to implement similar fix as referenced JDK bug report: retry and hope the best. Default value is 5 attempts (will retry 4 times).

See Also:

JDK-8252883, Constant Field Values

SYSTEM_PROP_SLEEP_MILLIS

public static final java.lang.String SYSTEM_PROP_SLEEP_MILLIS

Tweak: When SYSTEM_PROP_ATTEMPTS used, the amount of milliseconds to sleep between subsequent retries. Default value is 50 milliseconds.

See Also:

Constant Field Values

SYSTEM_PROP_MAX_CACHED_CHANNELS

public static final java.lang.String SYSTEM_PROP_MAX_CACHED_CHANNELS

Maximum number of idle (not currently locked) FileChannels to keep open for reuse. Keeping channels open avoids repeated open/creat syscalls, but each open channel consumes a file descriptor. On systems with low FD limits (e.g., macOS defaults to 256), large reactor builds with thousands of unique artifacts can exhaust the limit. This cap bounds idle channel retention; channels for actively held locks are never evicted.

See Also:

Constant Field Values

Constructor Detail

FileLockNamedLockFactory

public FileLockNamedLockFactory()

Method Detail

createLock

protected NamedLockSupport createLock(NamedLockKey key)

Description copied from class: NamedLockFactorySupport

Implementations shall create and return NamedLockSupport for given name, this method must never return null.

Specified by:

createLock in class NamedLockFactorySupport

destroyLock

protected void destroyLock(NamedLock namedLock)

Description copied from class: NamedLockFactorySupport

Implementation may override this (empty) method to perform some sort of implementation specific cleanup for given lock name. Invoked when reference count for given name drops to zero and named lock was removed.

Overrides:

destroyLock in class NamedLockFactorySupport

doShutdown

protected void doShutdown()

Overrides:

doShutdown in class NamedLockFactorySupport