Package org.eclipse.jetty.util.thread
Class ReservedThreadExecutor
- java.lang.Object
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- org.eclipse.jetty.util.component.AbstractLifeCycle
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- org.eclipse.jetty.util.thread.ReservedThreadExecutor
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- All Implemented Interfaces:
java.util.concurrent.Executor
,Dumpable
,LifeCycle
,TryExecutor
@ManagedObject("A pool for reserved threads") public class ReservedThreadExecutor extends AbstractLifeCycle implements TryExecutor, Dumpable
A TryExecutor using pre-allocated/reserved threads from an external Executor.
Calls to
tryExecute(Runnable)
on ReservedThreadExecutor will either succeed with a reserved thread immediately being assigned the task, or fail if no reserved thread is available.Threads are reserved lazily, with new reserved threads being allocated from the external
Executor
passed to the constructor. Whenever 1 or more reserved threads have been idle for more thangetIdleTimeoutMs()
then one reserved thread will return to the external Executor.
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Nested Class Summary
Nested Classes Modifier and Type Class Description private class
ReservedThreadExecutor.ReservedThread
private static class
ReservedThreadExecutor.State
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Nested classes/interfaces inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle
AbstractLifeCycle.AbstractLifeCycleListener
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Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.Dumpable
Dumpable.DumpableContainer
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Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.LifeCycle
LifeCycle.Listener
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Nested classes/interfaces inherited from interface org.eclipse.jetty.util.thread.TryExecutor
TryExecutor.NoTryExecutor
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Field Summary
Fields Modifier and Type Field Description private int
_capacity
private AtomicBiInteger
_count
private java.util.concurrent.Executor
_executor
private long
_idleTimeNanos
private java.util.concurrent.atomic.AtomicLong
_lastEmptyTime
private ThreadPoolBudget.Lease
_lease
private java.util.concurrent.SynchronousQueue<java.lang.Runnable>
_queue
private java.util.Set<ReservedThreadExecutor.ReservedThread>
_threads
private static long
DEFAULT_IDLE_TIMEOUT
private static Logger
LOG
private static java.lang.Runnable
STOP
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Fields inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle
FAILED, RUNNING, STARTED, STARTING, STOPPED, STOPPING
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Fields inherited from interface org.eclipse.jetty.util.thread.TryExecutor
NO_TRY
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Constructor Summary
Constructors Constructor Description ReservedThreadExecutor(java.util.concurrent.Executor executor, int capacity)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description void
doStart()
void
doStop()
void
dump(java.lang.Appendable out, java.lang.String indent)
Dump this object (and children) into an Appendable using the provided indent after any new lines.void
execute(java.lang.Runnable task)
int
getAvailable()
int
getCapacity()
java.util.concurrent.Executor
getExecutor()
long
getIdleTimeoutMs()
int
getPending()
private static int
reservedThreads(java.util.concurrent.Executor executor, int capacity)
void
setIdleTimeout(long idleTime, java.util.concurrent.TimeUnit idleTimeUnit)
Set the idle timeout for shrinking the reserved thread poolprivate void
startReservedThread()
java.lang.String
toString()
boolean
tryExecute(java.lang.Runnable task)
Executes the given task if and only if a reserved thread is available.-
Methods inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle
addLifeCycleListener, getState, getState, getStopTimeout, isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, removeLifeCycleListener, setStopTimeout, start, stop
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Field Detail
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LOG
private static final Logger LOG
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DEFAULT_IDLE_TIMEOUT
private static final long DEFAULT_IDLE_TIMEOUT
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STOP
private static final java.lang.Runnable STOP
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_executor
private final java.util.concurrent.Executor _executor
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_capacity
private final int _capacity
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_threads
private final java.util.Set<ReservedThreadExecutor.ReservedThread> _threads
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_queue
private final java.util.concurrent.SynchronousQueue<java.lang.Runnable> _queue
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_count
private final AtomicBiInteger _count
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_lastEmptyTime
private final java.util.concurrent.atomic.AtomicLong _lastEmptyTime
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_lease
private ThreadPoolBudget.Lease _lease
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_idleTimeNanos
private long _idleTimeNanos
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Constructor Detail
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ReservedThreadExecutor
public ReservedThreadExecutor(java.util.concurrent.Executor executor, int capacity)
- Parameters:
executor
- The executor to use to obtain threadscapacity
- The number of threads to preallocate. If less than 0 then capacity is calculated based on a heuristic from the number of available processors and thread pool size.
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Method Detail
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reservedThreads
private static int reservedThreads(java.util.concurrent.Executor executor, int capacity)
- Parameters:
executor
- The executor to use to obtain threadscapacity
- The number of threads to preallocate, If less than 0 then capacity is calculated based on a heuristic from the number of available processors and thread pool size.- Returns:
- the number of reserved threads that would be used by a ReservedThreadExecutor constructed with these arguments.
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getExecutor
public java.util.concurrent.Executor getExecutor()
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getCapacity
@ManagedAttribute(value="max number of reserved threads", readonly=true) public int getCapacity()
- Returns:
- the maximum number of reserved threads
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getAvailable
@ManagedAttribute(value="available reserved threads", readonly=true) public int getAvailable()
- Returns:
- the number of threads available to
tryExecute(Runnable)
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getPending
@ManagedAttribute(value="pending reserved threads", readonly=true) public int getPending()
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getIdleTimeoutMs
@ManagedAttribute(value="idle timeout in ms", readonly=true) public long getIdleTimeoutMs()
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setIdleTimeout
public void setIdleTimeout(long idleTime, java.util.concurrent.TimeUnit idleTimeUnit)
Set the idle timeout for shrinking the reserved thread pool- Parameters:
idleTime
- Time to wait before shrinking, or 0 for default timeout.idleTimeUnit
- Time units for idle timeout
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doStart
public void doStart() throws java.lang.Exception
- Overrides:
doStart
in classAbstractLifeCycle
- Throws:
java.lang.Exception
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doStop
public void doStop() throws java.lang.Exception
- Overrides:
doStop
in classAbstractLifeCycle
- Throws:
java.lang.Exception
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execute
public void execute(java.lang.Runnable task) throws java.util.concurrent.RejectedExecutionException
- Specified by:
execute
in interfacejava.util.concurrent.Executor
- Specified by:
execute
in interfaceTryExecutor
- Throws:
java.util.concurrent.RejectedExecutionException
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tryExecute
public boolean tryExecute(java.lang.Runnable task)
Executes the given task if and only if a reserved thread is available.
- Specified by:
tryExecute
in interfaceTryExecutor
- Parameters:
task
- the task to run- Returns:
- true if and only if a reserved thread was available and has been assigned the task to run.
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startReservedThread
private void startReservedThread()
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dump
public void dump(java.lang.Appendable out, java.lang.String indent) throws java.io.IOException
Description copied from interface:Dumpable
Dump this object (and children) into an Appendable using the provided indent after any new lines. The indent should not be applied to the first object dumped.
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toString
public java.lang.String toString()
- Overrides:
toString
in classAbstractLifeCycle
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