[#794] Wait for the listen port to be open before returning from connection...

Valery Kharseko

16 hours ago a2c7a1aafbd30c89e1c857ec8574080dcd83aa52

 opendj-server-legacy/src/main/java/org/forgerock/opendj/reactive/LDAPConnectionHandler2.java

@@ -190,6 +190,13 @@
     */
    private final Object waitListen = new Object();

    /**
     * Condition predicate for {@link #waitListen}: set once the handler thread has attempted to open the listen socket
     * (successfully or not). Guarded by the {@link #waitListen} monitor; protects the start method against spurious
     * wakeups.
     */
    private boolean listenAttempted;

    /** The friendly name of this connection handler. */
    private String friendlyName;

@@ -680,6 +687,38 @@
    }

    /**
     * {@inheritDoc}
     * <p>
     * Deliberately left unsynchronized, unlike the overridden {@link Thread#start()}: the state this method touches is
     * guarded by the {@link #waitListen} monitor, and holding the thread's own monitor across {@code waitListen.wait()}
     * would block {@link Thread#join()}.
     */
    @Override
    public void start() {
        // The Directory Server start process should only return when the connection handler port is fully opened
        // and working. The start method therefore needs to wait for the created thread.
        synchronized (waitListen) {
            super.start();

            final long deadlineNanos = System.nanoTime() + TimeUnit.MILLISECONDS.toNanos(LISTEN_TIMEOUT_MS);
            try {
                while (!listenAttempted) {
                    final long remainingMs = TimeUnit.NANOSECONDS.toMillis(deadlineNanos - System.nanoTime());
                    if (remainingMs <= 0) {
                        logger.error(ERR_CONNHANDLER_TIMEOUT_WAITING_FOR_LISTENER, handlerName,
                                TimeUnit.MILLISECONDS.toSeconds(LISTEN_TIMEOUT_MS));
                        break;
                    }
                    waitListen.wait(remainingMs);
                }
            } catch (InterruptedException e) {
                // If something interrupted the start its probably better to return ASAP.
                Thread.currentThread().interrupt();
            }
        }
    }

    /**
     * Operates in a loop, accepting new connections and ensuring that requests on those connections are handled
     * properly.
     */
@@ -702,6 +741,7 @@
                    // so notify here to allow the server startup to complete.
                    synchronized (waitListen) {
                        starting = false;
                        listenAttempted = true;
                        waitListen.notifyAll();
                    }
                }
@@ -717,12 +757,6 @@
            }

            try {
                // At this point, the connection Handler either started correctly or failed
                // to start but the start process should be notified and resume its work in any cases.
                synchronized (waitListen) {
                    waitListen.notifyAll();
                }

                // If we have gotten here, then we are about to start listening
                // for the first time since startup or since we were previously disabled.
                startListener();
@@ -750,6 +784,13 @@
                } else {
                    lastIterationFailed = true;
                }
            } finally {
                // At this point, the connection handler either started listening or failed to do so,
                // but the start process should be notified and resume its work in any cases.
                synchronized (waitListen) {
                    listenAttempted = true;
                    waitListen.notifyAll();
                }
            }
        }