1 /* 2 * Copyright (c) 2007, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 #include "jni.h" 25 26 extern "C" { 27 28 29 int always_true = 1; 30 31 JNIEXPORT jint JNICALL 32 Java_nsk_jdwp_ThreadReference_ForceEarlyReturn_forceEarlyReturn002_forceEarlyReturn002a_nativeMethod(JNIEnv *env, jobject classObject, jobject object) 33 { 34 int dummy_counter = 0; 35 // notify another thread that thread in native method 36 jclass klass = env->GetObjectClass(object); 37 jfieldID field = env->GetFieldID(klass, "threadInNative", "Z"); 38 env->SetBooleanField(object, field, 1); 39 40 // execute infinite loop to be sure that thread in native method 41 while (always_true) 42 { 43 // Need some dummy code so the optimizer does not remove this loop. 44 dummy_counter = dummy_counter < 1000 ? 0 : dummy_counter + 1; 45 } 46 // The optimizer can be surprisingly clever. 47 // Use dummy_counter so it can never be optimized out. 48 // This statement will always return 0. 49 return dummy_counter >= 0 ? 0 : 1; 50 } 51 52 }