8303485: Replacing os.name for operating system customization

Reviewed-by: naoto, erikj, alanb

make/modules/java.base/gensrc/GensrcMisc.gmk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2020, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -50,8 +50,14 @@ $(eval $(call SetupTextFileProcessing, BUILD_VERSION_JAVA, \
         @@VENDOR_URL_VM_BUG@@ => $(VENDOR_URL_VM_BUG), \
 ))
 
-TARGETS += $(BUILD_VERSION_JAVA)
+$(eval $(call SetupTextFileProcessing, BUILD_PLATFORMPROPERTIES_JAVA, \
+    SOURCE_FILES := $(TOPDIR)/src/java.base/share/classes/jdk/internal/util/OperatingSystemProps.java.template, \
+    OUTPUT_FILE := $(SUPPORT_OUTPUTDIR)/gensrc/java.base/jdk/internal/util/OperatingSystemProps.java, \
+    REPLACEMENTS := \
+        @@OPENJDK_TARGET_OS@@ => $(OPENJDK_TARGET_OS), \
+))
 
+TARGETS += $(BUILD_VERSION_JAVA) $(BUILD_PLATFORMPROPERTIES_JAVA)
 ################################################################################
 
 ifneq ($(filter $(TOOLCHAIN_TYPE), gcc clang), )

src/java.base/share/classes/java/lang/ProcessBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,7 @@
 
 package java.lang;
 
+import jdk.internal.util.OperatingSystem;
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.IOException;
@@ -35,7 +36,6 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import jdk.internal.event.ProcessStartEvent;
-import sun.security.action.GetPropertyAction;
 
 /**
  * This class is used to create operating system processes.
@@ -469,9 +469,8 @@ public final class ProcessBuilder
      * @since 1.7
      */
     public abstract static class Redirect {
-        private static final File NULL_FILE = new File(
+        private static final File NULL_FILE =
-                (GetPropertyAction.privilegedGetProperty("os.name")
+                new File((OperatingSystem.isWindows() ? "NUL" : "/dev/null")
-                        .startsWith("Windows") ? "NUL" : "/dev/null")
         );
 
         /**

src/java.base/share/classes/java/util/zip/ZipFile.java

@@ -63,7 +63,7 @@ import java.util.stream.StreamSupport;
 import jdk.internal.access.JavaUtilZipFileAccess;
 import jdk.internal.access.JavaUtilJarAccess;
 import jdk.internal.access.SharedSecrets;
-import jdk.internal.misc.VM;
+import jdk.internal.util.OperatingSystem;
 import jdk.internal.perf.PerfCounter;
 import jdk.internal.ref.CleanerFactory;
 import jdk.internal.vm.annotation.Stable;
@@ -1085,8 +1085,6 @@ public class ZipFile implements ZipConstants, Closeable {
         }
     }
 
-    private static boolean isWindows;
-
     static {
         SharedSecrets.setJavaUtilZipFileAccess(
             new JavaUtilZipFileAccess() {
@@ -1133,7 +1131,6 @@ public class ZipFile implements ZipConstants, Closeable {
 
              }
         );
-        isWindows = VM.getSavedProperty("os.name").contains("Windows");
     }
 
     private static class Source {
@@ -1321,7 +1318,7 @@ public class ZipFile implements ZipConstants, Closeable {
             this.zc = zc;
             this.key = key;
             if (toDelete) {
-                if (isWindows) {
+                if (OperatingSystem.isWindows()) {
                     this.zfile = SharedSecrets.getJavaIORandomAccessFileAccess()
                                               .openAndDelete(key.file, "r");
                 } else {

src/java.base/share/classes/jdk/internal/foreign/CABI.java

@@ -1,5 +1,5 @@
 /*
- *  Copyright (c) 2020, 2022, Oracle and/or its affiliates. All rights reserved.
+ *  Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
  *  DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  *  This code is free software; you can redistribute it and/or modify it
@@ -25,8 +25,10 @@
  */
 package jdk.internal.foreign;
 
+import jdk.internal.util.OperatingSystem;
+import jdk.internal.util.StaticProperty;
+
 import static java.lang.foreign.ValueLayout.ADDRESS;
-import static sun.security.action.GetPropertyAction.privilegedGetProperty;
 
 public enum CABI {
     SYS_V,
@@ -38,32 +40,30 @@ public enum CABI {
 
     private static final CABI ABI;
     private static final String ARCH;
-    private static final String OS;
     private static final long ADDRESS_SIZE;
 
     static {
-        ARCH = privilegedGetProperty("os.arch");
+        ARCH = StaticProperty.osArch();
-        OS = privilegedGetProperty("os.name");
         ADDRESS_SIZE = ADDRESS.bitSize();
         // might be running in a 32-bit VM on a 64-bit platform.
         // addressSize will be correctly 32
         if ((ARCH.equals("amd64") || ARCH.equals("x86_64")) && ADDRESS_SIZE == 64) {
-            if (OS.startsWith("Windows")) {
+            if (OperatingSystem.isWindows()) {
                 ABI = WIN_64;
             } else {
                 ABI = SYS_V;
             }
         } else if (ARCH.equals("aarch64")) {
-            if (OS.startsWith("Mac")) {
+            if (OperatingSystem.isMacOS()) {
                 ABI = MAC_OS_AARCH_64;
-            } else if (OS.startsWith("Windows")) {
+            } else if (OperatingSystem.isWindows()) {
                 ABI = WIN_AARCH_64;
             } else {
                 // The Linux ABI follows the standard AAPCS ABI
                 ABI = LINUX_AARCH_64;
             }
         } else if (ARCH.equals("riscv64")) {
-            if (OS.startsWith("Linux")) {
+            if (OperatingSystem.isLinux()) {
                 ABI = LINUX_RISCV_64;
             } else {
                 // unsupported
@@ -78,7 +78,8 @@ public enum CABI {
     public static CABI current() {
         if (ABI == null) {
             throw new UnsupportedOperationException(
-                    "Unsupported os, arch, or address size: " + OS + ", " + ARCH + ", " + ADDRESS_SIZE);
+                    "Unsupported os, arch, or address size: " + OperatingSystem.current() +
+                            ", " + ARCH + ", " + ADDRESS_SIZE);
         }
         return ABI;
     }

src/java.base/share/classes/jdk/internal/util/OperatingSystem.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package jdk.internal.util;
+
+import jdk.internal.util.OperatingSystemProps;
+import jdk.internal.vm.annotation.ForceInline;
+
+/**
+ * Enumeration of operating system types and testing for the current OS.
+ * The enumeration can be used to dispatch to OS specific code or values.
+ * Checking if a specific operating system is current uses a simple
+ * static method for each operating system.
+ * <p>
+ * For example,
+ * {@snippet lang = "java":
+ * if (OperatingSystem.isWindows()) {
+ *     // Windows only code.
+ * } else if (OperatingSystem.isLinux()) {
+ *     // Linux only code
+ * }
+ *}
+ *
+ * Alternatively, compare with the {@linkplain #current() current} operating system.
+ * For example,
+ * {@snippet lang = "java":
+ * if (OperatingSystem.current() == OperatingSystem.WINDOWS) {
+ *     // Windows only code.
+ * }
+ *}
+ * Dispatch based on the current operating system or choose a value.
+ * For example,
+ * {@snippet lang = "java":
+ * int port() {
+ *      return switch(OperatingSystem.current()) {
+ *          case LINUX->32768;
+ *          case AIX->32768;
+ *          case MACOS->49152;
+ *          case WINDOWS->49152;
+ *      };
+ * }
+ *}
+ */
+public enum OperatingSystem {
+
+    /**
+     * Operating systems based on the Linux kernel.
+     */
+    LINUX,
+    /**
+     * The Mac OS X Operating system.
+     */
+    MACOS,
+    /**
+     * The Windows Operating system.
+     */
+    WINDOWS,
+    /**
+     * The AIX Operating system.
+     */
+    AIX,
+    ;
+
+    // Cache a copy of the array for lightweight indexing
+    private static final OperatingSystem[] osValues = OperatingSystem.values();
+
+    /**
+     * {@return {@code true} if built for the Linux operating system}
+     */
+    @ForceInline
+    public static boolean isLinux() {
+        return OperatingSystemProps.TARGET_OS_IS_LINUX;
+    }
+
+    /**
+     * {@return {@code true} if built for the Mac OS X operating system}
+     */
+    @ForceInline
+    public static boolean isMacOS() {
+        return OperatingSystemProps.TARGET_OS_IS_MACOSX;
+    }
+
+    /**
+     * {@return {@code true} if built for the Windows operating system}
+     */
+    @ForceInline
+    public static boolean isWindows() {
+        return OperatingSystemProps.TARGET_OS_IS_WINDOWS;
+    }
+
+    /**
+     * {@return {@code true} if built for the AIX operating system}
+     */
+    @ForceInline
+    public static boolean isAix() {
+        return OperatingSystemProps.TARGET_OS_IS_AIX;
+    }
+
+    /**
+     * {@return the current operating system}
+     */
+    public static OperatingSystem current() {
+        return osValues[OperatingSystemProps.CURRENT_OS_ORDINAL];
+    }
+}

src/java.base/share/classes/jdk/internal/util/OperatingSystemProps.java.template

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package jdk.internal.util;
+
+/**
+ * The corresponding source file is generated by GensrcMisc.gmk for java.base.
+ * @see OperatingSystem
+ */
+class OperatingSystemProps {
+
+    // Unique integers named to match the build system naming of the build target
+    // The values must match the ordinals of the respective enum
+    private static final int TARGET_OS_linux   = 0;
+    private static final int TARGET_OS_macosx  = 1;
+    private static final int TARGET_OS_windows = 2;
+    private static final int TARGET_OS_aix     = 3;
+
+    // Index/ordinal of the current OperatingSystem enum as substituted by the build
+    static final int CURRENT_OS_ORDINAL = TARGET_OS_@@OPENJDK_TARGET_OS@@;
+
+    // Precomputed booleans for each Operating System
+    static final boolean TARGET_OS_IS_LINUX   = TARGET_OS_@@OPENJDK_TARGET_OS@@ == TARGET_OS_linux;
+    static final boolean TARGET_OS_IS_MACOSX  = TARGET_OS_@@OPENJDK_TARGET_OS@@ == TARGET_OS_macosx;
+    static final boolean TARGET_OS_IS_WINDOWS = TARGET_OS_@@OPENJDK_TARGET_OS@@ == TARGET_OS_windows;
+    static final boolean TARGET_OS_IS_AIX     = TARGET_OS_@@OPENJDK_TARGET_OS@@ == TARGET_OS_aix;
+}

src/java.base/share/classes/jdk/internal/util/StaticProperty.java

@@ -54,6 +54,8 @@ public final class StaticProperty {
     private static final String JAVA_PROPERTIES_DATE;
     private static final String SUN_JNU_ENCODING;
     private static final String JAVA_LOCALE_USE_OLD_ISO_CODES;
+    private static final String OS_NAME;
+    private static final String OS_ARCH;
 
     private StaticProperty() {}
 
@@ -73,6 +75,8 @@ public final class StaticProperty {
         JAVA_PROPERTIES_DATE = getProperty(props, "java.properties.date", null);
         SUN_JNU_ENCODING = getProperty(props, "sun.jnu.encoding");
         JAVA_LOCALE_USE_OLD_ISO_CODES = getProperty(props, "java.locale.useOldISOCodes", "");
+        OS_NAME = getProperty(props, "os.name");
+        OS_ARCH = getProperty(props, "os.arch");
     }
 
     private static String getProperty(Properties props, String key) {
@@ -243,4 +247,22 @@ public final class StaticProperty {
     public static String javaLocaleUseOldISOCodes() {
         return JAVA_LOCALE_USE_OLD_ISO_CODES;
     }
+
+     /**
+      * {@return the {@code os.name} system property}
+      * <strong>{@link SecurityManager#checkPropertyAccess} is NOT checked
+      * in this method. This property is not considered security sensitive.</strong>
+      */
+     public static String osName() {
+         return OS_NAME;
+     }
+
+     /**
+      * {@return the {@code os.arch} system property}
+      * <strong>{@link SecurityManager#checkPropertyAccess} is NOT checked
+      * in this method. This property is not considered security sensitive.</strong>
+      */
+     public static String osArch() {
+         return OS_ARCH;
+     }
 }

src/java.base/share/classes/sun/launcher/LauncherHelper.java

@@ -77,6 +77,7 @@ import java.util.jar.Manifest;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import jdk.internal.util.OperatingSystem;
 import jdk.internal.misc.VM;
 import jdk.internal.module.ModuleBootstrap;
 import jdk.internal.module.Modules;
@@ -168,7 +169,7 @@ public final class LauncherHelper {
                 printLocale();
                 break;
             case "system":
-                if (System.getProperty("os.name").contains("Linux")) {
+                if (OperatingSystem.isLinux()) {
                     printSystemMetrics();
                     break;
                 }
@@ -176,7 +177,7 @@ public final class LauncherHelper {
                 printVmSettings(initialHeapSize, maxHeapSize, stackSize);
                 printProperties();
                 printLocale();
-                if (System.getProperty("os.name").contains("Linux")) {
+                if (OperatingSystem.isLinux()) {
                     printSystemMetrics();
                 }
                 break;
@@ -532,7 +533,7 @@ public final class LauncherHelper {
         initOutput(printToStderr);
         ostream.println(getLocalizedMessage("java.launcher.X.usage",
                 File.pathSeparator));
-        if (System.getProperty("os.name").contains("OS X")) {
+        if (OperatingSystem.isMacOS()) {
             ostream.println(getLocalizedMessage("java.launcher.X.macosx.usage",
                         File.pathSeparator));
         }
@@ -745,7 +746,7 @@ public final class LauncherHelper {
         Class<?> c = null;
         try {
             c = Class.forName(m, mainClass);
-            if (c == null && System.getProperty("os.name", "").contains("OS X")
+            if (c == null && OperatingSystem.isMacOS()
                     && Normalizer.isNormalized(mainClass, Normalizer.Form.NFD)) {
 
                 String cn = Normalizer.normalize(mainClass, Normalizer.Form.NFC);
@@ -789,7 +790,7 @@ public final class LauncherHelper {
             try {
                 mainClass = Class.forName(cn, false, scl);
             } catch (NoClassDefFoundError | ClassNotFoundException cnfe) {
-                if (System.getProperty("os.name", "").contains("OS X")
+                if (OperatingSystem.isMacOS()
                         && Normalizer.isNormalized(cn, Normalizer.Form.NFD)) {
                     try {
                         // On Mac OS X since all names with diacritical marks are

src/java.base/share/classes/sun/net/sdp/SdpSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,7 +30,7 @@ import java.io.FileDescriptor;
 
 import jdk.internal.access.SharedSecrets;
 import jdk.internal.access.JavaIOFileDescriptorAccess;
-import sun.security.action.GetPropertyAction;
+import jdk.internal.util.OperatingSystem;
 
 
 /**
@@ -39,8 +39,7 @@ import sun.security.action.GetPropertyAction;
  */
 
 public final class SdpSupport {
-    private static final String os = GetPropertyAction.privilegedGetProperty("os.name");
+    private static final boolean isSupported = OperatingSystem.isLinux();
-    private static final boolean isSupported = os.equals("Linux");
     private static final JavaIOFileDescriptorAccess fdAccess =
         SharedSecrets.getJavaIOFileDescriptorAccess();
 

src/java.base/unix/classes/java/lang/ProcessImpl.java

@@ -37,19 +37,17 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.charset.Charset;
 import java.util.Arrays;
-import java.util.EnumSet;
 import java.util.Locale;
-import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.ReentrantLock;
 import java.security.AccessController;
-import java.security.PrivilegedAction;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
 import jdk.internal.access.JavaIOFileDescriptorAccess;
 import jdk.internal.access.SharedSecrets;
+import jdk.internal.util.OperatingSystem;
 import jdk.internal.util.StaticProperty;
 import sun.security.action.GetPropertyAction;
 
@@ -92,65 +90,39 @@ final class ProcessImpl extends Process {
         VFORK
     }
 
-    private static enum Platform {
+    /**
-
+     * {@return the default or requested launch mechanism}
-        LINUX(LaunchMechanism.POSIX_SPAWN, LaunchMechanism.VFORK, LaunchMechanism.FORK),
+     * @throws Error if the requested launch mechanism is not found or valid
-
+     */
-        BSD(LaunchMechanism.POSIX_SPAWN, LaunchMechanism.FORK),
+    private static LaunchMechanism launchMechanism() {
-
+        String s = GetPropertyAction.privilegedGetProperty("jdk.lang.Process.launchMechanism");
-        AIX(LaunchMechanism.POSIX_SPAWN, LaunchMechanism.FORK);
-
-        final LaunchMechanism defaultLaunchMechanism;
-        final Set<LaunchMechanism> validLaunchMechanisms;
-
-        Platform(LaunchMechanism ... launchMechanisms) {
-            this.defaultLaunchMechanism = launchMechanisms[0];
-            this.validLaunchMechanisms =
-                EnumSet.copyOf(Arrays.asList(launchMechanisms));
-        }
-
-        @SuppressWarnings("removal")
-        LaunchMechanism launchMechanism() {
-            return AccessController.doPrivileged(
-                (PrivilegedAction<LaunchMechanism>) () -> {
-                    String s = System.getProperty(
-                        "jdk.lang.Process.launchMechanism");
-                    LaunchMechanism lm;
         if (s == null) {
-                        lm = defaultLaunchMechanism;
+            return LaunchMechanism.POSIX_SPAWN;
-                        s = lm.name().toLowerCase(Locale.ROOT);
+        }
-                    } else {
+
         try {
-                            lm = LaunchMechanism.valueOf(
+            // Should be value of a LaunchMechanism enum
-                                s.toUpperCase(Locale.ROOT));
+            LaunchMechanism lm = LaunchMechanism.valueOf(s.toUpperCase(Locale.ROOT));
+            switch (OperatingSystem.current()) {
+                case LINUX:
+                    return lm;      // All options are valid for Linux
+                case AIX:
+                case MACOS:
+                    if (lm != LaunchMechanism.VFORK) {
+                        return lm; // All but VFORK are valid
+                    }
+                    break;
+                case WINDOWS:
+                    // fall through to throw to Error
+            }
         } catch (IllegalArgumentException e) {
-                            lm = null;
-                        }
-                    }
-                    if (lm == null || !validLaunchMechanisms.contains(lm)) {
-                        throw new Error(
-                            s + " is not a supported " +
-                            "process launch mechanism on this platform."
-                        );
-                    }
-                    return lm;
-                }
-            );
         }
 
-        static Platform get() {
+        throw new Error(s + " is not a supported " +
-            String osName = GetPropertyAction.privilegedGetProperty("os.name");
+            "process launch mechanism on this platform: " + OperatingSystem.current());
-
-            if (osName.equals("Linux")) { return LINUX; }
-            if (osName.contains("OS X")) { return BSD; }
-            if (osName.equals("AIX")) { return AIX; }
-
-            throw new Error(osName + " is not a supported OS platform.");
-        }
     }
 
-    private static final Platform platform = Platform.get();
+    private static final LaunchMechanism launchMechanism = launchMechanism();
-    private static final LaunchMechanism launchMechanism = platform.launchMechanism();
     private static final byte[] helperpath = toCString(StaticProperty.javaHome() + "/lib/jspawnhelper");
 
     private static byte[] toCString(String s) {
@@ -354,9 +326,9 @@ final class ProcessImpl extends Process {
      * @throws IOException
      */
     void initStreams(int[] fds, boolean forceNullOutputStream) throws IOException {
-        switch (platform) {
+        switch (OperatingSystem.current()) {
             case LINUX:
-            case BSD:
+            case MACOS:
                 stdin = (fds[0] == -1) ?
                         ProcessBuilder.NullOutputStream.INSTANCE :
                         new ProcessPipeOutputStream(fds[0]);
@@ -428,7 +400,9 @@ final class ProcessImpl extends Process {
                 });
                 break;
 
-            default: throw new AssertionError("Unsupported platform: " + platform);
+            default:
+                throw new AssertionError("Unsupported platform: " +
+                    OperatingSystem.current());
         }
     }
 
@@ -484,9 +458,9 @@ final class ProcessImpl extends Process {
     }
 
     private void destroy(boolean force) {
-        switch (platform) {
+        switch (OperatingSystem.current()) {
             case LINUX:
-            case BSD:
+            case MACOS:
             case AIX:
                 // There is a risk that pid will be recycled, causing us to
                 // kill the wrong process!  So we only terminate processes
@@ -506,7 +480,7 @@ final class ProcessImpl extends Process {
                 try { stderr.close(); } catch (IOException ignored) {}
                 break;
 
-            default: throw new AssertionError("Unsupported platform: " + platform);
+            default: throw new AssertionError("Unsupported platform: " + OperatingSystem.current());
         }
     }
 

src/java.base/unix/classes/sun/net/PortConfig.java

@@ -25,7 +25,7 @@
 
 package sun.net;
 
-import sun.security.action.GetPropertyAction;
+import jdk.internal.util.OperatingSystem;
 
 /**
  * Determines the ephemeral port range in use on this system.
@@ -42,14 +42,16 @@ public final class PortConfig {
 
     static {
         jdk.internal.loader.BootLoader.loadLibrary("net");
-        String os = GetPropertyAction.privilegedGetProperty("os.name");
+        switch (OperatingSystem.current()) {
-        if (os.startsWith("Linux")) {
+            case LINUX:
                 defaultLower = 32768;
                 defaultUpper = 61000;
-        } else if (os.contains("OS X")) {
+                break;
+            case MACOS:
                 defaultLower = 49152;
                 defaultUpper = 65535;
-        } else if (os.startsWith("AIX")) {
+                break;
+            case AIX:
                 // The ephemeral port is OS version dependent on AIX:
                 // http://publib.boulder.ibm.com/infocenter/aix/v7r1/topic/com.ibm.aix.rsct315.admin/bl503_ephport.htm
                 // However, on AIX 5.3 / 6.1 / 7.1 we always see the
@@ -57,9 +59,9 @@ public final class PortConfig {
                 // /usr/sbin/no -a | fgrep ephemeral
                 defaultLower = 32768;
                 defaultUpper = 65535;
-        } else {
+                break;
-            throw new InternalError(
+            default:
-                "sun.net.PortConfig: unknown OS");
+                throw new InternalError("sun.net.PortConfig: unsupported OS: " + OperatingSystem.current());
         }
 
         int v = getLower0();

test/jdk/java/foreign/TestUnsupportedLinker.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -24,8 +24,8 @@
 /*
  * @test
  * @enablePreview
- *
+ * @summary test with unknown architecture override
- * @run testng/othervm -Dos.arch=unknown -Dos.name=unknown --enable-native-access=ALL-UNNAMED TestUnsupportedLinker
+ * @run testng/othervm -Dos.arch=unknown --enable-native-access=ALL-UNNAMED TestUnsupportedLinker
  */
 
 import java.lang.foreign.Linker;

test/jdk/jdk/internal/util/OSTest.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+
+import java.util.Locale;
+import java.util.stream.Stream;
+
+import jdk.internal.util.OperatingSystem;
+
+import static jdk.internal.util.OperatingSystem.AIX;
+import static jdk.internal.util.OperatingSystem.LINUX;
+import static jdk.internal.util.OperatingSystem.MACOS;
+import static jdk.internal.util.OperatingSystem.WINDOWS;
+
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
+/**
+ * @test
+ * @summary test OperatingSystem enum
+ * @modules java.base/jdk.internal.util
+ * @run junit OSTest
+ */
+
+public class OSTest {
+    /**
+     * Test consistency of System property "os.name" with OperatingSystem.current().
+     */
+    @Test
+    public void os_nameVsCurrent() {
+        String osName = System.getProperty("os.name").substring(0, 3).toLowerCase(Locale.ROOT);
+        OperatingSystem os = switch (osName) {
+            case "win" -> WINDOWS;
+            case "lin" -> LINUX;
+            case "mac" -> MACOS;
+            case "aix" -> AIX;
+            default    -> fail("Unknown os.name: " + osName);
+        };
+        assertEquals(OperatingSystem.current(), os, "mismatch in OperatingSystem.current vs " + osName);
+    }
+
+    /**
+     * Test various OperatingSystem enum values vs boolean isXXX() methods.
+     * @return a stream of arguments for parameterized test
+     */
+    private static Stream<Arguments> osParams() {
+        return Stream.of(
+                Arguments.of(LINUX, OperatingSystem.isLinux()),
+                Arguments.of(WINDOWS, OperatingSystem.isWindows()),
+                Arguments.of(MACOS, OperatingSystem.isMacOS()),
+                Arguments.of(AIX, OperatingSystem.isAix())
+        );
+    }
+
+    @ParameterizedTest
+    @MethodSource("osParams")
+    public void isXXX(OperatingSystem os, boolean isXXX) {
+        OperatingSystem current = OperatingSystem.current();
+        assertEquals(os == current, isXXX,
+                "Mismatch " + os + " == " + current + " vs is" + os);
+    }
+ }