Modifier and Type	Class and Description
pack-priv static class	WeakConcurrentMap.LookupKey<K>
public static class	WeakConcurrentMap.WithInlinedExpunction<K, V> A `WeakConcurrentMap` where stale entries are removed as a side effect of interacting with this map.

Modifier and Type	Field and Description
private static final AtomicLong	ID
private static final ThreadLocal<WeakConcurrentMap.LookupKey<?>>	LOOKUP_KEY_CACHE Lookup keys are cached thread-locally to avoid allocations on lookups.
private final boolean	reuseKeys
private final Thread	thread

Constructor Summary

Access	Constructor and Description
public	WeakConcurrentMap(boolean `true` if a thread should be started that removes stale entries. cleanerThread)
public	WeakConcurrentMap(boolean `true` if a thread should be started that removes stale entries. cleanerThread, boolean `true` if the lookup keys should be reused via a `ThreadLocal`. Note that setting this to `true` may result in class loader leaks. See `isPersistentClassLoader(ClassLoader)` for more details. reuseKeys)
public	WeakConcurrentMap(boolean `true` if a thread should be started that removes stale entries. cleanerThread, boolean `true` if the lookup keys should be reused via a `ThreadLocal`. Note that setting this to `true` may result in class loader leaks. See `isPersistentClassLoader(ClassLoader)` for more details. reuseKeys, ConcurrentMap<AbstractWeakConcurrentMap.WeakKey<K>, V> ConcurrentMap implementation that this class wraps. target)

Method Summary

Modifier and Type	Method and Description
public Thread	Returns: The cleaner thread or `null` if no such thread was set. getCleanerThread()
protected WeakConcurrentMap.LookupKey<K>	getLookupKey(K key) Implements abstract io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.getLookupKey. Override with care as it can cause lookup failures if done incorrectly.
private static boolean	Returns: `true` if the provided class loader can be unloaded. isPersistentClassLoader(ClassLoader The class loader to check. classLoader) Checks whether the provided `ClassLoader` may be unloaded like a web application class loader, for example.
protected void	resetLookupKey(WeakConcurrentMap.LookupKey<K> lookupKey) Implements abstract io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.resetLookupKey. Resets any reusable state in the lookup key.

Inherited from io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap:: approximateSize clear containsKey defaultValue expungeStaleEntries get getIfPresent iterator put putIfAbsent putIfProbablyAbsent remove run toString

ID	back to summary
private static final AtomicLong ID

LOOKUP_KEY_CACHE	back to summary
private static final ThreadLocal<WeakConcurrentMap.LookupKey<?>> LOOKUP_KEY_CACHE Lookup keys are cached thread-locally to avoid allocations on lookups. This is beneficial as the JIT unfortunately can't reliably replace the `LookupKey` allocation with stack allocations, even though the `LookupKey` does not escape.

reuseKeys	back to summary
private final boolean reuseKeys

thread	back to summary
private final Thread thread

Constructor Detail

WeakConcurrentMap	back to summary
public WeakConcurrentMap(boolean cleanerThread) Parameters cleanerThread:boolean `true` if a thread should be started that removes stale entries.

WeakConcurrentMap	back to summary
public WeakConcurrentMap(boolean cleanerThread, boolean reuseKeys) Parameters cleanerThread:boolean `true` if a thread should be started that removes stale entries. reuseKeys:boolean `true` if the lookup keys should be reused via a `ThreadLocal`. Note that setting this to `true` may result in class loader leaks. See `isPersistentClassLoader(ClassLoader)` for more details.

WeakConcurrentMap back to summary

WeakConcurrentMap	back to summary
public WeakConcurrentMap(boolean cleanerThread, boolean reuseKeys, ConcurrentMap<AbstractWeakConcurrentMap.WeakKey<K>, V> target) Parameters cleanerThread:boolean `true` if a thread should be started that removes stale entries. reuseKeys:boolean `true` if the lookup keys should be reused via a `ThreadLocal`. Note that setting this to `true` may result in class loader leaks. See `isPersistentClassLoader(ClassLoader)` for more details. target:ConcurrentMap<AbstractWeakConcurrentMap.WeakKey<K>, V> ConcurrentMap implementation that this class wraps.

public WeakConcurrentMap(boolean cleanerThread, boolean reuseKeys, ConcurrentMap<AbstractWeakConcurrentMap.WeakKey<K>, V> target)

Parameters

cleanerThread:boolean: true if a thread should be started that removes stale entries.
reuseKeys:boolean: true if the lookup keys should be reused via a ThreadLocal. Note that setting this to true may result in class loader leaks. See isPersistentClassLoader(ClassLoader) for more details.
target:ConcurrentMap<AbstractWeakConcurrentMap.WeakKey<K>, V>: ConcurrentMap implementation that this class wraps.

Method Detail

getCleanerThread	back to summary
public Thread getCleanerThread() Returns:Thread The cleaner thread or `null` if no such thread was set.

getLookupKey back to summary

getLookupKey	back to summary
protected WeakConcurrentMap.LookupKey<K> getLookupKey(K key) Implements abstract io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.getLookupKey. Doc from io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.getLookupKey. Override with care as it can cause lookup failures if done incorrectly. The result must have the same `Object#hashCode()` as the input and be `equal to` a weak reference of the key. When overriding this, also override `resetLookupKey`. Annotations @Override @SuppressWarnings:unchecked

protected WeakConcurrentMap.LookupKey<K> getLookupKey(K key)

Implements abstract io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.getLookupKey.

Doc from io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.getLookupKey.

Override with care as it can cause lookup failures if done incorrectly. The result must have the same Object#hashCode() as the input and be equal to a weak reference of the key. When overriding this, also override resetLookupKey.

Annotations

@Override
@SuppressWarnings:unchecked

isPersistentClassLoader back to summary

isPersistentClassLoader	back to summary
private static boolean isPersistentClassLoader(ClassLoader classLoader) Checks whether the provided `ClassLoader` may be unloaded like a web application class loader, for example. If the class loader can't be unloaded, it is safe to use `ThreadLocal`s and to reuse the `LookupKey`. Otherwise, the use of `ThreadLocal`s may lead to class loader leaks as it prevents the class loader this class is loaded by to unload. Parameters classLoader:ClassLoader The class loader to check. Returns:boolean `true` if the provided class loader can be unloaded.

private static boolean isPersistentClassLoader(ClassLoader classLoader)

Checks whether the provided ClassLoader may be unloaded like a web application class loader, for example.

If the class loader can't be unloaded, it is safe to use ThreadLocals and to reuse the LookupKey. Otherwise, the use of ThreadLocals may lead to class loader leaks as it prevents the class loader this class is loaded by to unload.

Parameters

classLoader:ClassLoader: The class loader to check.

Returns:boolean

true if the provided class loader can be unloaded.

resetLookupKey	back to summary
protected void resetLookupKey(WeakConcurrentMap.LookupKey<K> lookupKey) Implements abstract io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.resetLookupKey. Doc from io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.resetLookupKey. Resets any reusable state in the lookup key. Annotations @Override

resetLookupKey

back to summary

protected void resetLookupKey(WeakConcurrentMap.LookupKey<K> lookupKey)

Implements abstract io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.resetLookupKey.

Doc from io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.resetLookupKey.

Resets any reusable state in the lookup key.

Annotations

@Override

io.opentelemetry.context.internal.shaded back to summary

pack-priv final Class WeakConcurrentMap.LookupKey<K>

Class Inheritance

extends Object

java.lang.Object
io.opentelemetry.context.internal.shaded.WeakConcurrentMap.LookupKey

Field Summary

Modifier and Type	Field and Description
private int	hashCode
private K	key

Constructor Summary

Access	Constructor and Description
pack-priv	LookupKey()

Method Summary

Modifier and Type	Method and Description
public boolean	equals(Object the reference object with which to compare. other) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
public int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for this object.
pack-priv void	reset() Failing to reset a lookup key can lead to memory leaks as the key is strongly referenced.
pack-priv WeakConcurrentMap.LookupKey<K>	withValue(K key)

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll toString wait wait wait

Field Detail

hashCode	back to summary
private int hashCode

key	back to summary
private K key

Constructor Detail

LookupKey	back to summary
pack-priv LookupKey()

Method Detail

equals back to summary

equals	back to summary
public boolean equals(Object other) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Parameters other:Object the reference object with which to compare. Returns:boolean `true` if this object is the same as the obj argument; `false` otherwise. Annotations @Override

public boolean equals(Object other)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

other:Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@Override

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Returns:int a hash code value for this object Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object

Annotations

@Override

reset	back to summary
pack-priv void reset() Failing to reset a lookup key can lead to memory leaks as the key is strongly referenced.

withValue	back to summary
pack-priv WeakConcurrentMap.LookupKey<K> withValue(K key)

Modifier and Type	Method and Description
public int	approximateSize() Overrides io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.approximateSize. Returns the approximate size of this map where the returned number is at least as big as the actual number of entries.
public boolean	containsKey(K The key of the entry. key) Overrides io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.containsKey.
public V	get(K The key of the entry. key) Overrides io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.get.
public Iterator<Map.Entry<K, V>>	iterator() Overrides io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.iterator. Implements java.lang.Iterable.iterator. Returns an iterator over elements of type `T`.
public V	put(K The key of the entry. key, V The value of the entry. value) Overrides io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.put.
public V	remove(K The key of the entry. key) Overrides io.opentelemetry.context.internal.shaded.AbstractWeakConcurrentMap.remove.

public Class WeakConcurrentMap<K, V>

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

pack-priv final Class WeakConcurrentMap.LookupKey<K>

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public Class WeakConcurrentMap.WithInlinedExpunction<K, V>

Constructor Summary

Method Summary

Constructor Detail

Method Detail