1 /*
   2  * Copyright (c) 2014, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #include <windows.h>
  27 
  28 #include "jni_util.h"
  29 #include "jlong.h"
  30 #include "jdk_internal_jimage_concurrent_ConcurrentPReader.h"
  31 
  32 static jfieldID handle_fdID;
  33 
  34 JNIEXPORT void JNICALL
  35 Java_jdk_internal_jimage_concurrent_ConcurrentPReader_initIDs(JNIEnv *env, jclass clazz)
  36 {
  37     CHECK_NULL(clazz = (*env)->FindClass(env, "java/io/FileDescriptor"));
  38     CHECK_NULL(handle_fdID = (*env)->GetFieldID(env, clazz, "handle", "J"));
  39 }
  40 
  41 JNIEXPORT jint JNICALL
  42 Java_jdk_internal_jimage_concurrent_ConcurrentPReader_pread(JNIEnv *env, jclass clazz,
  43                                                             jobject fdo, jlong address,
  44                                                             jint len, jlong offset)
  45 {
  46     OVERLAPPED ov;
  47     DWORD nread;
  48     BOOL result;
  49 
  50     jlong handle = (*env)->GetLongField(env, fdo, handle_fdID);
  51     void *buf = (void *)jlong_to_ptr(address);
  52 
  53     ZeroMemory(&ov, sizeof(ov));
  54     ov.Offset = (DWORD)offset;
  55     ov.OffsetHigh = (DWORD)(offset >> 32);
  56 
  57     result = ReadFile(handle, (LPVOID)buf, len, &nread, &ov);
  58     if (result == 0) {
  59         JNU_ThrowIOExceptionWithLastError(env, "ReadFile failed");
  60     }
  61 
  62     return nread;
  63 }
  64