content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF 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 com.datastax.oss.driver.internal.core.os;
  
  import com.oracle.svm.core.annotate.Substitute;
  import com.oracle.svm.core.annotate.TargetClass;
  import java.util.Optional;
  
  /**
   * Add an explicit Graal substitution for {@link JnrLibc}. If we don't implement something like this
   * the analysis done at Graal native image build time will discover the jnr-posix references in
   * JnrLibc even though they won't be used at runtime. By default jnr-ffi (used by jnr-posix to do
   * it's work) will use {@link ClassLoader#defineClass(String, byte[], int, int)} which isn't
   * supported by Graal. This behaviour can be changed with a system property but the cleanest
   * solution is simply to remove the references to jnr-posix code via a Graal substitution.
   */
  @TargetClass(JnrLibc.class)
  @Substitute
  final class JnrLibcSubstitution implements Libc {
  
    @Substitute
    public JnrLibcSubstitution() {}
  
    @Substitute
    @Override
    public boolean available() {
      return false;
    }
  
    @Substitute
    @Override
    public Optional<Long> gettimeofday() {
      return Optional.empty();
    }
  
    @Substitute
    @Override
    public Optional<Integer> getpid() {
      return Optional.empty();
    }
  }
  