ConditionVariable

Kotlin |Java

@UnstableApi
public class ConditionVariable

An interruptible condition variable. This class provides a number of benefits over :

Consistent use of (elapsedRealtime for timing block timeout intervals. android.os.ConditionVariable used currentTimeMillis prior to Android 10, which is not a correct clock to use for interval timing because it's not guaranteed to be monotonic.
Support for injecting a custom Clock.
The ability to query the variable's current state, by calling isOpen.
open and close return whether they changed the variable's state.

Summary

Public fields
`boolean`	`isOpen`

Public constructors
`ConditionVariable()` Creates a closed instance using `DEFAULT`.
`ConditionVariable(Clock clock)` Creates an instance, which starts closed.

Public methods
`synchronized void`	`block()` Blocks until the condition is opened.
`synchronized boolean`	`block(long timeoutMs)` Blocks until the condition is opened or until `timeoutMs` have passed.
`synchronized void`	`blockUninterruptible()` Blocks until the condition is open.
`synchronized boolean`	`close()` Closes the condition.
`synchronized boolean`	`isOpen()` Returns whether the condition is opened.
`synchronized boolean`	`open()` Opens the condition and releases all threads that are blocked.

Public fields

isOpen

public boolean isOpen

Public constructors

ConditionVariable

public ConditionVariable()

Creates a closed instance using DEFAULT.

ConditionVariable

public ConditionVariable(Clock clock)

Creates an instance, which starts closed.

Parameters
`Clock clock`	The `Clock` whose `elapsedRealtime` method is used to determine when `block` should time out.

Public methods

block

synchronized public void block()

Blocks until the condition is opened.

Throws
`java.lang.InterruptedException`	If the thread is interrupted.

block

synchronized public boolean block(long timeoutMs)

Blocks until the condition is opened or until timeoutMs have passed.

Parameters
`long timeoutMs`	The maximum time to wait in milliseconds. If `timeoutMs <= 0` then the call will return immediately without blocking.

Returns
`boolean`	True if the condition was opened, false if the call returns because of the timeout.

Throws
`java.lang.InterruptedException`	If the thread is interrupted.

blockUninterruptible

synchronized public void blockUninterruptible()

Blocks until the condition is open. Unlike block, this method will continue to block if the calling thread is interrupted. If the calling thread was interrupted then its interrupted status will be set when the method returns.

close

synchronized public boolean close()

Closes the condition.

Returns
`boolean`	True if the condition variable was closed. False if it was already closed.

isOpen

synchronized public boolean isOpen()

Returns whether the condition is opened.

open

synchronized public boolean open()

Opens the condition and releases all threads that are blocked.

Returns
`boolean`	True if the condition variable was opened. False if it was already open.