Added time to error message when port open timed out. (#9287)

Author: AlexeyKuznetsov-DD

dd-java-agent/testing/src/main/groovy/datadog/trace/agent/test/utils/PortUtils.java

@@ -105,7 +105,8 @@ private static boolean isPortOpen(String host, int port) {
 
   public static void waitForPortToOpen(
       final int port, final long timeout, final TimeUnit unit, final Process process) {
-    final long waitUntil = System.currentTimeMillis() + unit.toMillis(timeout);
+    final long startedAt = System.currentTimeMillis();
+    final long waitUntil = startedAt + unit.toMillis(timeout);
 
     while (System.currentTimeMillis() < waitUntil) {
       try {
@@ -133,7 +134,13 @@ public static void waitForPortToOpen(
       }
     }
 
-    throw new RuntimeException("Timed out waiting for port " + port + " to be opened");
+    throw new RuntimeException(
+        "Timed out waiting for port "
+            + port
+            + " to be opened, started to wait at: "
+            + startedAt
+            + ", timed out at: "
+            + System.currentTimeMillis());
   }
 
   public static void waitForPortToOpen(String host, int port, long timeout, TimeUnit unit) {

dd-java-agent/testing/src/test/groovy/utils/PortUtilsTest.groovy

@@ -0,0 +1,70 @@
+package utils
+
+import datadog.trace.agent.test.AgentTestRunner
+import datadog.trace.agent.test.utils.PortUtils
+
+import java.util.concurrent.TimeUnit
+
+class PortUtilsTest extends AgentTestRunner {
+  def "expect waitForPortToOpen succeed"() {
+    given:
+    int port = PortUtils.randomOpenPort()
+    def socket = new ServerSocket(port) // Emulating port opened.
+
+    def process = Mock(Process)
+    process.isAlive() >> true
+
+    when:
+    PortUtils.waitForPortToOpen(port, 1, TimeUnit.SECONDS, process)
+
+    then:
+    noExceptionThrown()
+
+    cleanup:
+    socket.close()
+  }
+
+  def "expect to handle port open timeout"() {
+    given:
+    int port = PortUtils.randomOpenPort()
+    def process = Mock(Process)
+    process.isAlive() >> true
+
+    when:
+    PortUtils.waitForPortToOpen(port, 1, TimeUnit.SECONDS, process)
+
+    then:
+    def ex = thrown(RuntimeException)
+    ex.message.startsWith("Timed out waiting for port $port to be opened, started to wait at:")
+  }
+
+  def "expect to handle process abnormal termination"() {
+    given:
+    int port = PortUtils.randomOpenPort()
+    def process = Mock(Process)
+    process.isAlive() >> false
+    process.exitValue() >> 123
+
+    when:
+    PortUtils.waitForPortToOpen(port, 1, TimeUnit.SECONDS, process)
+
+    then:
+    def ex = thrown(RuntimeException)
+    ex.message == "Process exited abnormally exitCode=123 before port=$port was opened"
+  }
+
+  def "expect to handle process termination before port opened"() {
+    given:
+    int port = PortUtils.randomOpenPort()
+    def process = Mock(Process)
+    process.isAlive() >> false
+    process.exitValue() >> 0
+
+    when:
+    PortUtils.waitForPortToOpen(port, 1, TimeUnit.SECONDS, process)
+
+    then:
+    def ex = thrown(RuntimeException)
+    ex.message == "Process finished before port=$port was opened"
+  }
+}