Closed a connection when occurred RejectedExecutionException on TcpNioConnection#checkForAssembler

[kazuki43zoo]

In what version(s) of Spring Integration are you seeing this issue?

6.4.9

Describe the bug

Closed a connection when occurred the RejectedExecutionException on TcpNioConnection#checkForAssembler.
Because It catch at readPacket method as follow:

	public void readPacket() {
		if (logger.isDebugEnabled()) {
			logger.debug(getConnectionId() + " Reading...");
		}
		try {
			doRead();
		}
		catch (@SuppressWarnings(UNUSED) ClosedChannelException cce) {
			if (logger.isDebugEnabled()) {
				logger.debug(getConnectionId() + " Channel is closed");
			}
			closeConnection(true);
		}
		catch (Exception e) {
			logger.error("Exception on Read " + getConnectionId() + " " + e.getMessage(), e);
			closeConnection(true); // ★★★★★ close connection this code
		}
	}

On the other hand, AbstractConnectionFactory is implemented assuming that a RejectedExecutionException will be thrown from readPacket method.

				boolean delayed = false;
				try {
					connection.readPacket();
				}
				catch (@SuppressWarnings(UNUSED) RejectedExecutionException e1) { // ★★★★ Current implementation is dead code
					delayRead(selector, now, key);
					delayed = true;
				}

Expected behavior

Instead of closing the connection, it will be delayed Read.
How about modifying it as follows?

	public void readPacket() {
		if (logger.isDebugEnabled()) {
			logger.debug(getConnectionId() + " Reading...");
		}
		try {
			doRead();
		}
		catch (@SuppressWarnings(UNUSED) ClosedChannelException cce) {
			if (logger.isDebugEnabled()) {
				logger.debug(getConnectionId() + " Channel is closed");
			}
			closeConnection(true);
		}
+		catch (RejectedExecutionException ree) {
+			throw ree;
+		}
		catch (Exception e) {
			logger.error("Exception on Read " + getConnectionId() + " " + e.getMessage(), e);
			closeConnection(true);
		}
	}

The behavior seems to have changed in the following commit:

19b9944#diff-6451fd5c22e08caea6f3005257a2c56b99adfac27424810b8375d8848a73b61b

[cppwfs]

Thank you writing a well crafted issue. It was most helpful!
Would you like to contribute the fix for this issue?

[kazuki43zoo]

@cppwfs OK, I will try to fix this issue!