Merge pull request #1429 from nats-io/write-timeout-tuning

Ensure write timeout is not less than 100 nanoseconds

Author: scottf

src/main/java/io/nats/client/Options.java

@@ -125,6 +125,11 @@ public class Options {
     @Deprecated
     public static final long MINIMUM_SOCKET_WRITE_TIMEOUT_GT_CONNECTION_TIMEOUT = 100;
 
+    /**
+     * This is set to 100 nanos to ensure that the scheduled task can execute
+     */
+    public static final long MINIMUM_SOCKET_WRITE_TIMEOUT_NANOS = 100;
+
     /**
      * @deprecated No longer enforcing a minimum
      */
@@ -1955,8 +1960,8 @@ else if (useDefaultTls) {
                 socketReadTimeoutMillis = 0; // just for consistency. The connection compares to gt 0
             }
 
-            if (socketWriteTimeout != null && socketWriteTimeout.toMillis() < 1) {
-                socketWriteTimeout = null;
+            if (socketWriteTimeout != null && socketWriteTimeout.toNanos() < MINIMUM_SOCKET_WRITE_TIMEOUT_NANOS) {
+                throw new IllegalArgumentException("Socket Write Timeout cannot be less than " + MINIMUM_SOCKET_WRITE_TIMEOUT_NANOS + " nanoseconds.");
             }
 
             if (socketSoLinger < 0) {

src/main/java/io/nats/client/impl/SocketDataPortWithWriteTimeout.java

@@ -21,6 +21,7 @@
 import org.jspecify.annotations.NonNull;
 
 import java.io.IOException;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
 
 /**
@@ -30,7 +31,7 @@
 public class SocketDataPortWithWriteTimeout extends SocketDataPort {
 
     private long writeTimeoutNanos;
-    private long delayPeriodMillis;
+    private long delayPeriodNanos;
     private ScheduledTask writeWatchTask;
     private final AtomicLong writeMustBeDoneBy;
 
@@ -41,21 +42,16 @@ public SocketDataPortWithWriteTimeout() {
     @Override
     public void afterConstruct(Options options) {
         super.afterConstruct(options);
-        long writeTimeoutMillis;
-        if (options.getSocketWriteTimeout() == null) {
-            writeTimeoutMillis = Options.DEFAULT_SOCKET_WRITE_TIMEOUT.toMillis();
-        }
-        else {
-            writeTimeoutMillis = options.getSocketWriteTimeout().toMillis();
-        }
-        delayPeriodMillis = writeTimeoutMillis * 51 / 100;
-        writeTimeoutNanos = writeTimeoutMillis * 1_000_000;
+        writeTimeoutNanos = options.getSocketWriteTimeout() == null
+            ? Options.DEFAULT_SOCKET_WRITE_TIMEOUT.toNanos()
+            : options.getSocketWriteTimeout().toNanos();
+        delayPeriodNanos = writeTimeoutNanos * 51 / 100;
     }
 
     @Override
     public void connect(@NonNull NatsConnection conn, @NonNull NatsUri nuri, long timeoutNanos) throws IOException {
         super.connect(conn, nuri, timeoutNanos);
-        writeWatchTask = new ScheduledTask(conn.getScheduledExecutor(), delayPeriodMillis,
+        writeWatchTask = new ScheduledTask(conn.getScheduledExecutor(), delayPeriodNanos, TimeUnit.NANOSECONDS,
             () -> {
                 //  if now is after when it was supposed to be done by
                 if (NatsSystemClock.nanoTime() > writeMustBeDoneBy.get()) {

src/main/java/io/nats/client/support/ScheduledTask.java

@@ -67,7 +67,7 @@ public ScheduledTask(String id, ScheduledExecutorService ses, long initialDelay,
         this.initialDelayNanos = unit.toNanos(initialDelay);
         this.periodNanos = unit.toNanos(period);
         scheduledFutureRef = new AtomicReference<>(
-            ses.scheduleAtFixedRate(this, initialDelay, period, unit));
+            ses.scheduleAtFixedRate(this, initialDelayNanos, periodNanos, TimeUnit.NANOSECONDS));
     }
 
     public long getInitialDelayNanos() {