org.openqa.selenium.net.PortProber Maven / Gradle / Ivy
Show all versions of selenium-api Show documentation
// Licensed to the Software Freedom Conservancy (SFC) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The SFC licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
package org.openqa.selenium.net;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.net.ConnectException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import org.openqa.selenium.Platform;
public class PortProber {
public static final int HIGHEST_PORT = 65535;
public static final int START_OF_USER_PORTS = 1024;
private static final Random random = new Random();
private static final EphemeralPortRangeDetector ephemeralRangeDetector;
private static final Platform current = Platform.getCurrent();
static {
if (current.is(Platform.LINUX)) {
ephemeralRangeDetector = LinuxEphemeralPortRangeDetector.getInstance();
} else if (current.is(Platform.XP)) {
ephemeralRangeDetector = new OlderWindowsVersionEphemeralPortDetector();
} else {
ephemeralRangeDetector = new FixedIANAPortRange();
}
}
private PortProber() {
// Utility class
}
public static int findFreePort() {
for (int i = 0; i < 5; i++) {
int seedPort = createAcceptablePort();
int suggestedPort = checkPortIsFree(seedPort);
if (suggestedPort != -1) {
return suggestedPort;
}
}
throw new RuntimeException("Unable to find a free port");
}
/**
* Returns a port that is within a probable free-range.
*
*
Based on the ports in ..., this
* method stays away from all well-known ephemeral port ranges, since they can arbitrarily race
* with the operating system in allocations. Due to the port-greedy nature of selenium this
* happens fairly frequently. Staying within the known safe range increases the probability tests
* will run green quite significantly.
*
* @return a random port number
*/
private static int createAcceptablePort() {
synchronized (random) {
final int FIRST_PORT;
final int LAST_PORT;
int ephemeralStart =
Math.max(START_OF_USER_PORTS, ephemeralRangeDetector.getLowestEphemeralPort());
int ephemeralEnd = Math.min(HIGHEST_PORT, ephemeralRangeDetector.getHighestEphemeralPort());
/*
* If the system provides a too short range of ephemeral ports (mostly on old windows systems)
* use the range suggested from Internet Assigned Numbers Authority as ephemeral port range.
*/
if (ephemeralEnd - ephemeralStart < 5000) {
EphemeralPortRangeDetector ianaRange = new FixedIANAPortRange();
ephemeralStart = ianaRange.getLowestEphemeralPort();
ephemeralEnd = ianaRange.getHighestEphemeralPort();
}
int freeAbove = HIGHEST_PORT - ephemeralEnd;
int freeBelow = Math.max(0, ephemeralStart - START_OF_USER_PORTS);
if (freeAbove > freeBelow) {
FIRST_PORT = ephemeralEnd;
LAST_PORT = 65535;
} else {
FIRST_PORT = 1024;
LAST_PORT = ephemeralStart;
}
if (FIRST_PORT == LAST_PORT) {
return FIRST_PORT;
}
if (FIRST_PORT > LAST_PORT) {
throw new UnsupportedOperationException("Could not find ephemeral port to use");
}
final int randomInt = random.nextInt();
final int portWithoutOffset = Math.abs(randomInt % (LAST_PORT - FIRST_PORT + 1));
return portWithoutOffset + FIRST_PORT;
}
}
private static boolean isFree(String bindHost, int port) {
try (ServerSocket socket = new ServerSocket()) {
socket.setReuseAddress(true);
socket.bind(new InetSocketAddress(bindHost, port));
return true;
} catch (Exception e) {
return false;
}
}
static int checkPortIsFree(int port) {
if (isFree("localhost", port) && isFree("0.0.0.0", port)) {
return port;
}
return -1;
}
public static void waitForPortUp(int port, int timeout, TimeUnit unit) {
long end = System.currentTimeMillis() + unit.toMillis(timeout);
while (System.currentTimeMillis() < end) {
try (Socket socket = new Socket()) {
socket.connect(new InetSocketAddress("localhost", port), 1000);
return;
} catch (ConnectException | SocketTimeoutException e) {
// Ignore this
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
}
}