8274397: [macOS] Stop setting env. var JAVA_MAIN_CLASS_<pid> in launcher code

src/java.base/macosx/native/libjli/java_md_macosx.m

@@ -793,7 +793,7 @@ static void MacOSXStartup(int argc, char *argv[]) {
          * change drastically between update release, and it may even be
          * removed or replaced with another mechanism.
          *
-         * NOTE: It is used by SWT, and JavaFX.
+         * NOTE: It is used by SWT
          */
         snprintf(envVar, sizeof(envVar), "APP_NAME_%d", getpid());
         setenv(envVar, (arg + 12), 1);
@@ -828,40 +828,78 @@ static void MacOSXStartup(int argc, char *argv[]) {
     jmethodID getCanonicalNameMID = NULL;
     NULL_CHECK(getCanonicalNameMID = (*env)->GetMethodID(env, classClass, "getCanonicalName", "()Ljava/lang/String;"));
 
+    jclass strClass = NULL;
+    NULL_CHECK(strClass = (*env)->FindClass(env, "java/lang/String"));
+
+    jmethodID lastIndexMID = NULL;
+    NULL_CHECK(lastIndexMID = (*env)->GetMethodID(env, strClass, "lastIndexOf", "(I)I"));
+
+    jmethodID subStringMID = NULL;
+    NULL_CHECK(subStringMID = (*env)->GetMethodID(env, strClass, "substring", "(I)Ljava/lang/String;"));
+
     jstring mainClassString = (*env)->CallObjectMethod(env, mainClass, getCanonicalNameMID);
     if ((*env)->ExceptionCheck(env) || NULL == mainClassString) {
-        /*
-         * Clears all errors caused by getCanonicalName() on the mainclass and
-         * leaves the JAVA_MAIN_CLASS__<pid> empty.
-         */
         (*env)->ExceptionClear(env);
         return;
     }
 
-    const char *mainClassName = NULL;
-    NULL_CHECK(mainClassName = (*env)->GetStringUTFChars(env, mainClassString, NULL));
+    jint lastPeriod = (*env)->CallIntMethod(env, mainClassString, lastIndexMID, (jint)'.');
+    if ((*env)->ExceptionCheck(env)) {
+        (*env)->ExceptionClear(env);
+        return;
+    }
 
-    char envVar[80];
-    /*
-     * The JAVA_MAIN_CLASS_<pid> environment variable is used to pass
-     * the name of a Java class whose main() method is invoked by
-     * the Java launcher code to start the application, to the AWT code
-     * in order to assign the name to the Apple menu bar when the app
-     * is active on the Mac.
-     * The _<pid> part is added to avoid collisions with child processes.
-     *
-     * WARNING: This environment variable is an implementation detail and
-     * isn't meant for use outside of the core platform. The mechanism for
-     * passing this information from Java launcher to other modules may
-     * change drastically between update release, and it may even be
-     * removed or replaced with another mechanism.
+    if (lastPeriod != -1) {
+        mainClassString = (*env)->CallObjectMethod(env, mainClassString, subStringMID, lastPeriod+1);
+        if ((*env)->ExceptionCheck(env)) {
+            (*env)->ExceptionClear(env);
+            return;
+        }
+    }
+
+    /* There are multiple apple.awt.*" system properties that AWT(the desktop module)
+     * references that are inherited from Apple JDK.
+     * This inherited AWT code looks for this property and uses it for the name
+     * of the app as it appears in the system menu bar.
      *
-     * NOTE: It is used by SWT, and JavaFX.
+     * No idea if how much external code ever sets it, but use it if set, else
+     * if not set (the high probability event) set it to the application class name.
      */
-    snprintf(envVar, sizeof(envVar), "JAVA_MAIN_CLASS_%d", getpid());
-    setenv(envVar, mainClassName, 1);
+    const char* propName = "apple.awt.application.name";
+    jstring jKey = NULL;
+    NULL_CHECK(jKey = (*env)->NewStringUTF(env, propName));
+
+    jclass sysClass = NULL;
+    NULL_CHECK(sysClass = (*env)->FindClass(env, "java/lang/System"));
+
+    jmethodID getPropertyMID = NULL;
+    NULL_CHECK(getPropertyMID = (*env)->GetStaticMethodID(env, sysClass,
+               "getProperty", "(Ljava/lang/String;)Ljava/lang/String;"));
+
+    jmethodID setPropertyMID = NULL;
+    NULL_CHECK(setPropertyMID = (*env)->GetStaticMethodID(env, sysClass,
+               "setProperty",
+               "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;"));
+
+    jstring jValue = (*env)->CallStaticObjectMethod(env, sysClass, getPropertyMID, jKey);
+    if ((*env)->ExceptionCheck(env)) {
+        (*env)->ExceptionClear(env);
+        (*env)->DeleteLocalRef(env, jKey);
+        return;
+    }
+    if (jValue == NULL) {
+        (*env)->CallStaticObjectMethod(env, sysClass, setPropertyMID,
+                                       jKey, mainClassString);
+        if ((*env)->ExceptionCheck(env)) {
+            (*env)->ExceptionClear(env);
+            (*env)->DeleteLocalRef(env, jKey);
+            return;
+        }
+    } else {
+        (*env)->DeleteLocalRef(env, jValue);
+    }
 
-    (*env)->ReleaseStringUTFChars(env, mainClassString, mainClassName);
+    (*env)->DeleteLocalRef(env, jKey);
 }
 
 void

src/java.desktop/macosx/native/libosxapp/NSApplicationAWT.m

@@ -180,26 +180,11 @@ - (void) registerWithProcessManager
     }
 
     // If it wasn't specified as an argument, see if it was specified as a system property.
+    // The launcher code sets this if it is not already set on the command line.
     if (fApplicationName == nil) {
         fApplicationName = [PropertiesUtilities javaSystemPropertyForKey:@"apple.awt.application.name" withEnv:env];
     }
 
-    // If we STILL don't have it, the app name is retrieved from an environment variable (set in java.c) It should be UTF8.
-    if (fApplicationName == nil) {
-        char mainClassEnvVar[80];
-        snprintf(mainClassEnvVar, sizeof(mainClassEnvVar), "JAVA_MAIN_CLASS_%d", getpid());
-        char *mainClass = getenv(mainClassEnvVar);
-        if (mainClass != NULL) {
-            fApplicationName = [NSString stringWithUTF8String:mainClass];
-            unsetenv(mainClassEnvVar);
-
-            NSRange lastPeriod = [fApplicationName rangeOfString:@"." options:NSBackwardsSearch];
-            if (lastPeriod.location != NSNotFound) {
-                fApplicationName = [fApplicationName substringFromIndex:lastPeriod.location + 1];
-            }
-        }
-    }
-
     // The dock name is nil for double-clickable Java apps (bundled and Web Start apps)
     // When that happens get the display name, and if that's not available fall back to
     // CFBundleName.

test/jdk/tools/launcher/MacOSAppNamePropertyTest.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2021, 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.
+ */
+
+/**
+ * @test
+ * @bug 8274397
+ * @summary Ensure the app name system property is set on macOS
+ * @requires os.family == "mac"
+ * @compile MacOSAppNamePropertyTest.java SystemPropertyTest.java
+ * @run main MacOSAppNamePropertyTest
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+/*
+ * If the system property apple.awt.application.name is unset, it should default
+ * to the name of this test class.
+ * If it is set, then it should be used instead of the class.
+ * The arg. to the test indicates the *expected* name.
+ * The test will fail if the property is not set or does not match
+ */
+public class MacOSAppNamePropertyTest extends TestHelper {
+
+    static final String APPNAME = "SystemPropertyTest";
+
+    public static void main(String[]args) {
+        if (!isMacOSX) {
+            return;
+        }
+        execTest(null, APPNAME);
+        execTest("-Dapple.awt.application.name=Foo", "Foo");
+    }
+
+    static void execTest(String propSetting, String expect) {
+        List<String> cmdList = new ArrayList<>();
+        cmdList.add(javaCmd);
+        if (propSetting != null) {
+            cmdList.add(propSetting);
+        }
+        cmdList.add(APPNAME);
+        cmdList.add(expect);
+        TestResult tr = doExec(cmdList.toArray(new String[cmdList.size()]));
+        if (!tr.isOK()) {
+            System.err.println(tr.toString());
+            throw new RuntimeException("Test Fails");
+        }
+    }
+}

test/jdk/tools/launcher/SystemPropertyTest.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2021, 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.
+ */
+
+
+/*
+ * Child launched by MacOSAppNamePropertyTest.java
+ * If the system property apple.awt.application.name is unset, it should default
+ * to the name of this main program class, less any package name.
+ * If it is set, then it should be used instead of the class name.
+ * The arg. to the test indicates the *expected* name.
+ * The test will fail if the property is not set or does not match
+ */
+public class SystemPropertyTest {
+
+    public static void main(String[]args) {
+        String prop = System.getProperty("apple.awt.application.name");
+        if (prop == null) {
+            throw new RuntimeException("Property not set");
+        }
+        if (!prop.equals(args[0])) {
+            throw new RuntimeException("Got " + prop + " expected " + args[0]);
+        }
+    }
+}

test/jdk/tools/launcher/TestSpecialArgs.java

@@ -83,15 +83,11 @@ void testDocking() {
         Set<String> envToRemove = new HashSet<>();
         Map<String, String> map = System.getenv();
         for (String s : map.keySet()) {
-            if (s.startsWith("JAVA_MAIN_CLASS_")
-                    || s.startsWith("APP_NAME_")
+            if (s.startsWith("APP_NAME_")
                     || s.startsWith("APP_ICON_")) {
                 envToRemove.add(s);
             }
         }
-        runTest(envToRemove, javaCmd, "-cp", TEST_CLASSES_DIR.getAbsolutePath(),
-                "EnvironmentVariables", "JAVA_MAIN_CLASS_*",
-                "EnvironmentVariables");
 
         runTest(envToRemove, javaCmd, "-cp", TEST_CLASSES_DIR.getAbsolutePath(),
                 "-Xdock:name=TestAppName", "EnvironmentVariables",