EventPumper (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- net.i2p.router.transport.ntcp.EventPumper

All Implemented Interfaces:
Runnable
```
class EventPumper
extends Object
implements Runnable
```
The main NTCP NIO event loop thread responsible for high-throughput, low-latency handling of inbound and outbound NTCP connections using non-blocking I/O.
This class is optimized for minimal overhead and maximum event dispatch efficiency. All hot paths (e.g., processRead(java.nio.channels.SelectionKey), processWrite(java.nio.channels.SelectionKey), runDelayedEvents()) avoid synchronization, allocations, and unnecessary syscalls.
Key performance characteristics:
- Fixed 200ms selector timeout for consistent latency
- Immediate wakeup() on pending I/O
- Duplicate-free write request tracking via ConcurrentHashSet
- Spin detection: yields briefly when select() returns repeatedly without blocking
- Failsafe iteration every 2 seconds to clean stale connections
- Efficient buffer pooling with bounded size

Constructor Summary
Constructors
Constructor and Description
EventPumper(RouterContext ctx, NTCPTransport transport)
EventPumper.

Constructors
Constructor and Description
`EventPumper(RouterContext ctx, NTCPTransport transport)` EventPumper.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static ByteBuffer`	`acquireBuf()` High-frequency path in thread.
`void`	`blockIP(byte[] ip)` Record the given IP as blocked.
`static void`	`clearInterest(SelectionKey key, int op)` Clear the given interest operation on the selection key.
`static long`	`getFailsafeIterationFreq()` Failsafe iteration frequency in milliseconds.
`long`	`getIdleTimeout()` The idle timeout for connections.
`static int`	`getMaxIdleLps()` Max idle loop rate in loops per second.
`static long`	`getSelectorLoopDelay()` Selector loop delay in milliseconds.
`boolean`	`isAlive()` Selector can take quite a while to close after calling stopPumping()
`boolean`	`processWrite(NTCPConnection con, SelectionKey key)` Try to write the queued buffers for the connection.
`void`	`register(ServerSocketChannel chan)` Register the acceptor.
`void`	`registerConnect(NTCPConnection con)` Outbound connection registration with optional retry backoff.
`static void`	`releaseBuf(ByteBuffer buf)` Read buffer returned to the pool.
`void`	`run()` Run the selector event loop.
`static void`	`setFailsafeIterationFreq(long ms)` Failsafe iteration frequency, bounded by MIN-MAX.
`static void`	`setInterest(SelectionKey key, int op)` Interest operations on the given selection key.
`static void`	`setMaxIdleLps(int lps)` Max idle loop rate in loops per second, bounded 1-5000.
`static void`	`setSelectorLoopDelay(long ms)` Selector loop delay, bounded 1-SELECTOR_MAX_DELAY ms.
`void`	`startPumping()` Open the selector and start the pump thread.
`void`	`stopPumping()` Stop the pump thread and wake the selector.
`void`	`trackFailedInboundHandshake(byte[] ip)` Track failed inbound handshake (IP only, no hash).
`void`	`trackFailedInboundHandshake(byte[] ip, Hash hash)` Track failed inbound handshake for diagnostic stats.
`void`	`trackInvalidEncryption(byte[] ip, Hash hash)` Track failed inbound handshake with invalid encryption and ban if too many failures.
`void`	`wantsRead(NTCPConnection con)` This is only called from NTCPConnection.complete() if there is more data, which is rare (never?) so we don't need to check for dups or make _wantsRead a Set.
`void`	`wantsWrite(NTCPConnection con)` Called by the connection when it has data ready to write (after bw allocation).

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - EventPumper
```
public EventPumper(RouterContext ctx,
                   NTCPTransport transport)
```
    EventPumper.
- Method Detail
  - acquireBuf
```
public static ByteBuffer acquireBuf()
```
    High-frequency path in thread.
  - blockIP
```
public void blockIP(byte[] ip)
```
    Record the given IP as blocked.
  - clearInterest
```
public static void clearInterest(SelectionKey key,
                                 int op)
                          throws CancelledKeyException
```
    Clear the given interest operation on the selection key.
    Throws:
    CancelledKeyException
  - getFailsafeIterationFreq
```
public static long getFailsafeIterationFreq()
```
    Failsafe iteration frequency in milliseconds.
  - getIdleTimeout
```
public long getIdleTimeout()
```
    The idle timeout for connections.
    Returns:
    the idle timeout
  - getMaxIdleLps
```
public static int getMaxIdleLps()
```
    Max idle loop rate in loops per second.
  - getSelectorLoopDelay
```
public static long getSelectorLoopDelay()
```
    Selector loop delay in milliseconds.
  - isAlive
```
public boolean isAlive()
```
    Selector can take quite a while to close after calling stopPumping()
    Returns:
    whether alive
  - processWrite
```
public boolean processWrite(NTCPConnection con,
                            SelectionKey key)
```
    Try to write the queued buffers for the connection.
  - register
```
public void register(ServerSocketChannel chan)
```
    Register the acceptor. This is only called from NTCPTransport.bindAddress(), so it isn't clear why this needs a queue.
  - registerConnect
```
public void registerConnect(NTCPConnection con)
```
    Outbound connection registration with optional retry backoff.
  - releaseBuf
```
public static void releaseBuf(ByteBuffer buf)
```
    Read buffer returned to the pool. These buffers must be from acquireBuf(), i.e. capacity() == BUF_SIZE. High-frequency path in thread.
  - run
```
public void run()
```
    Run the selector event loop.
    Specified by:
    run in interface Runnable
  - setFailsafeIterationFreq
```
public static void setFailsafeIterationFreq(long ms)
```
    Failsafe iteration frequency, bounded by MIN-MAX.
  - setInterest
```
public static void setInterest(SelectionKey key,
                               int op)
                        throws CancelledKeyException
```
    Interest operations on the given selection key.
    Throws:
    CancelledKeyException
  - setMaxIdleLps
```
public static void setMaxIdleLps(int lps)
```
    Max idle loop rate in loops per second, bounded 1-5000. The pumper enforces this as a minimum idle iteration time (1e9 / rate), capping idle busy-spin even when selector wakeups defeat the timeout.
  - setSelectorLoopDelay
```
public static void setSelectorLoopDelay(long ms)
```
    Selector loop delay, bounded 1-SELECTOR_MAX_DELAY ms. Updates the base delay the pumper relaxes toward and raises the live delay immediately so Tuner-driven increases take effect without waiting for the pumper's own 60s ramp.
  - startPumping
```
public void startPumping()
```
    Open the selector and start the pump thread.
  - stopPumping
```
public void stopPumping()
```
    Stop the pump thread and wake the selector.
  - trackFailedInboundHandshake
```
public void trackFailedInboundHandshake(byte[] ip)
```
    Track failed inbound handshake (IP only, no hash).
  - trackFailedInboundHandshake
```
public void trackFailedInboundHandshake(byte[] ip,
                                        Hash hash)
```
    Track failed inbound handshake for diagnostic stats. Handshake timeouts on the open internet are network noise, not hostile, so we do not ban for them.
    Parameters:
    ip - source IP address (tracked for stats only)
    hash - optional router hash if available
  - trackInvalidEncryption
```
public void trackInvalidEncryption(byte[] ip,
                                   Hash hash)
```
    Track failed inbound handshake with invalid encryption and ban if too many failures. Ban reason: "Invalid encryption"
    Parameters:
    ip - byte array IP address
    hash - optional router hash if available
  - wantsRead
```
public void wantsRead(NTCPConnection con)
```
    This is only called from NTCPConnection.complete() if there is more data, which is rare (never?) so we don't need to check for dups or make _wantsRead a Set.
  - wantsWrite
```
public void wantsWrite(NTCPConnection con)
```
    Called by the connection when it has data ready to write (after bw allocation). Only wakeup if new.

Class EventPumper

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

EventPumper

Method Detail

acquireBuf

blockIP

clearInterest

getFailsafeIterationFreq

getIdleTimeout

getMaxIdleLps

getSelectorLoopDelay

isAlive

processWrite

register

registerConnect

releaseBuf

run

setFailsafeIterationFreq

setInterest

setMaxIdleLps

setSelectorLoopDelay

startPumping

stopPumping

trackFailedInboundHandshake

trackFailedInboundHandshake

trackInvalidEncryption

wantsRead

wantsWrite