shadows/framework/src/main/java/org/robolectric/shadows/ShadowSharedMemory.java
@Implementation
  protected ByteBuffer map(int prot, int offset, int length) throws ErrnoException {
    ReflectionHelpers.callInstanceMethod(realObject, "checkOpen");
    File file = filesByFd.get(getRealFileDescriptor());
    if (file == null) {
      throw new IllegalStateException("SharedMemory from a parcel isn't yet implemented!");
    }

    try (RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw")) {
      // It would be easy to support a MapMode.READ_ONLY type mapping as well except none of the
      // OsConstants fields are even initialized by robolectric and so "prot" is always zero!
      return randomAccessFile.getChannel().map(MapMode.READ_WRITE, offset, length);
    } catch (IOException e) {
      throw new ErrnoException(e.getMessage(), OsConstants.EIO, e);
    }
  }
@Implementation
  protected ByteBuffer map(int prot, int offset, int length) throws ErrnoException {
    ReflectionHelpers.callInstanceMethod(realObject, "checkOpen");
    File file = filesByFd.get(getRealFileDescriptor());
    if (file == null) {
      throw new IllegalStateException("SharedMemory from a parcel isn't yet implemented!");
    }

    try (RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw")) {
      // It would be easy to support a MapMode.READ_ONLY type mapping as well except none of the
      // OsConstants fields are even initialized by robolectric and so "prot" is always zero!
      return randomAccessFile.getChannel().map(MapMode.READ_WRITE, offset, length);
    } catch (IOException e) {
      throw new ErrnoException(e.getMessage(), OsConstants.EIO, e);
    }
  }
Only works on {@link SharedMemory} instances from {@link SharedMemory#create}.

<p>"prot" is ignored -- all mappings are read/write.