1 /* 2 * Copyright (c) 2001, 2010, 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 "jni.h" 27 #include "jni_util.h" 28 #include "jvm.h" 29 #include "jlong.h" 30 #include "java_nio_MappedByteBuffer.h" 31 #include <stdlib.h> 32 33 JNIEXPORT jboolean JNICALL 34 Java_java_nio_MappedByteBuffer_isLoaded0(JNIEnv *env, jobject obj, jlong address, 35 jlong len, jint numPages) 36 { 37 jboolean loaded = JNI_FALSE; 38 /* Information not available? 39 MEMORY_BASIC_INFORMATION info; 40 void *a = (void *) jlong_to_ptr(address); 41 int result = VirtualQuery(a, &info, (DWORD)len); 42 */ 43 return loaded; 44 } 45 46 JNIEXPORT void JNICALL 47 Java_java_nio_MappedByteBuffer_load0(JNIEnv *env, jobject obj, jlong address, 48 jlong len) 49 { 50 // no madvise available 51 } 52 53 JNIEXPORT void JNICALL 54 Java_java_nio_MappedByteBuffer_force0(JNIEnv *env, jobject obj, jobject fdo, 55 jlong address, jlong len) 56 { 57 void *a = (void *) jlong_to_ptr(address); 58 BOOL result; 59 int retry; 60 61 /* 62 * FlushViewOfFile can fail with ERROR_LOCK_VIOLATION if the memory 63 * system is writing dirty pages to disk. As there is no way to 64 * synchronize the flushing then we retry a limited number of times. 65 */ 66 retry = 0; 67 do { 68 result = FlushViewOfFile(a, (DWORD)len); 69 if ((result != 0) || (GetLastError() != ERROR_LOCK_VIOLATION)) 70 break; 71 retry++; 72 } while (retry < 3); 73 74 /** 75 * FlushViewOfFile only initiates the writing of dirty pages to disk 76 * so we have to call FlushFileBuffers to and ensure they are written. 77 */ 78 if (result != 0) { 79 // by right, the jfieldID initialization should be in a static 80 // initializer but we do it here instead to avoiding needing to 81 // load nio.dll during startup. 82 static jfieldID handle_fdID; 83 HANDLE h; 84 if (handle_fdID == NULL) { 85 jclass clazz = (*env)->FindClass(env, "java/io/FileDescriptor"); 86 if (clazz == NULL) 87 return; // exception thrown 88 handle_fdID = (*env)->GetFieldID(env, clazz, "handle", "J"); 89 } 90 h = jlong_to_ptr((*env)->GetLongField(env, fdo, handle_fdID)); 91 result = FlushFileBuffers(h); 92 if (result == 0 && GetLastError() == ERROR_ACCESS_DENIED) { 93 // read-only mapping 94 result = 1; 95 } 96 } 97 98 if (result == 0) { 99 JNU_ThrowIOExceptionWithLastError(env, "Flush failed"); 100 } 101 }