1 /*
   2  * Copyright (c) 2007, 2017 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 static volatile int release_critical = 0;
  27 
  28 JNIEXPORT jboolean JNICALL Java_CSLocker_lock
  29   (JNIEnv *env, jobject obj, jintArray array)
  30 {
  31     jboolean retval = JNI_TRUE;
  32     void *nativeArray = (*env)->GetPrimitiveArrayCritical(env, array, 0);
  33 
  34     if (nativeArray == NULL) {
  35         retval = JNI_FALSE;
  36     }
  37 
  38     // deadblock
  39     while (!release_critical) /* empty */;
  40 
  41     (*env)->ReleasePrimitiveArrayCritical(env, array, nativeArray, 0);
  42     return retval;
  43 }
  44 
  45 JNIEXPORT void JNICALL Java_CSLocker_unlock
  46   (JNIEnv *env, jobject obj)
  47 {
  48     release_critical = 1;
  49 }