src/java.base/share/classes/sun/nio/ch/IOUtil.java

*** 27,36 ****
--- 27,41 ----
  
  import java.io.FileDescriptor;
  import java.io.IOException;
  import java.nio.ByteBuffer;
  
+ import jdk.internal.misc.JavaIOFileDescriptorAccess;
+ import jdk.internal.misc.JavaNioAccess;
+ import jdk.internal.misc.SharedSecrets;
+ import jdk.internal.ref.Cleaner;
+ import sun.security.action.GetPropertyAction;
  
  /**
   * File-descriptor based I/O utilities that are shared by NIO classes.
   */
  
*** 39,48 ****
--- 44,56 ----
      /**
       * Max number of iovec structures that readv/writev supports
       */
      static final int IOV_MAX;
  
+     private static final JavaIOFileDescriptorAccess fdAccess =
+        SharedSecrets.getJavaIOFileDescriptorAccess();
+ 
      private IOUtil() { }                // No instantiation
  
      static int write(FileDescriptor fd, ByteBuffer src, long position,
                       NativeDispatcher nd)
          throws IOException
*** 84,97 ****
--- 92,113 ----
  
          int written = 0;
          if (rem == 0)
              return 0;
          if (position != -1) {
+             if (fdAccess.getDirect(fd))
+                 written = nd.pwriteDirect(fd,
+                                           ((DirectBuffer)bb).address() + pos,
+                                           rem, position);
+             else
                  written = nd.pwrite(fd,
                                      ((DirectBuffer)bb).address() + pos,
                                      rem, position);
          } else {
+             if (fdAccess.getDirect(fd))
+                 written = nd.writeDirect(fd, ((DirectBuffer)bb).address() + pos, rem);
+             else
                  written = nd.write(fd, ((DirectBuffer)bb).address() + pos, rem);
          }
          if (written > 0)
              bb.position(pos + written);
          return written;
*** 143,153 ****
                  i++;
              }
              if (iov_len == 0)
                  return 0L;
  
!             long bytesWritten = nd.writev(fd, vec.address, iov_len);
  
              // Notify the buffers how many bytes were taken
              long left = bytesWritten;
              for (int j=0; j<iov_len; j++) {
                  if (left > 0) {
--- 159,173 ----
                  i++;
              }
              if (iov_len == 0)
                  return 0L;
  
!             long bytesWritten;
!             if (fdAccess.getDirect(fd))          
!                 bytesWritten = nd.writevDirect(fd, vec.address, iov_len);
!             else
!                 bytesWritten = nd.writev(fd, vec.address, iov_len);
  
              // Notify the buffers how many bytes were taken
              long left = bytesWritten;
              for (int j=0; j<iov_len; j++) {
                  if (left > 0) {
*** 215,227 ****
--- 235,254 ----
  
          if (rem == 0)
              return 0;
          int n = 0;
          if (position != -1) {
+             if (fdAccess.getDirect(fd))
+                 n = nd.preadDirect(fd, ((DirectBuffer)bb).address() + pos,
+                              rem, position);
+             else
                  n = nd.pread(fd, ((DirectBuffer)bb).address() + pos,
                               rem, position);
          } else {
+             if (fdAccess.getDirect(fd))
+                 n = nd.readDirect(fd, ((DirectBuffer)bb).address() + pos, rem);
+             else
                  n = nd.read(fd, ((DirectBuffer)bb).address() + pos, rem);
          }
          if (n > 0)
              bb.position(pos + n);
          return n;
*** 272,283 ****
                  }
                  i++;
              }
              if (iov_len == 0)
                  return 0L;
! 
!             long bytesRead = nd.readv(fd, vec.address, iov_len);
  
              // Notify the buffers how many bytes were read
              long left = bytesRead;
              for (int j=0; j<iov_len; j++) {
                  ByteBuffer shadow = vec.getShadow(j);
--- 299,313 ----
                  }
                  i++;
              }
              if (iov_len == 0)
                  return 0L;
!             long bytesRead;
!             if (fdAccess.getDirect(fd))
!                 bytesRead = nd.readvDirect(fd, vec.address, iov_len);
!             else
!                 bytesRead = nd.readv(fd, vec.address, iov_len);
  
              // Notify the buffers how many bytes were read
              long left = bytesRead;
              for (int j=0; j<iov_len; j++) {
                  ByteBuffer shadow = vec.getShadow(j);