# HG changeset patch # User twisti # Date 1430150561 25200 # Node ID 476c276de939f8a043c4f3d4eab55fb439f7aab6 # Parent b39d2cec50566109de59ffa16772daa145699eba 8022853: add ability to load uncompressed object and Klass references in a compressed environment to Unsafe Reviewed-by: coleenp, jrose, kvn diff -r b39d2cec5056 -r 476c276de939 hotspot/src/share/vm/prims/unsafe.cpp --- a/hotspot/src/share/vm/prims/unsafe.cpp Mon Apr 27 14:41:49 2015 +0200 +++ b/hotspot/src/share/vm/prims/unsafe.cpp Mon Apr 27 09:02:41 2015 -0700 @@ -172,18 +172,6 @@ oop p = JNIHandles::resolve(obj); \ OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), x); -// Macros for oops that check UseCompressedOops - -#define GET_OOP_FIELD(obj, offset, v) \ - oop p = JNIHandles::resolve(obj); \ - oop v; \ - if (UseCompressedOops) { \ - narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); \ - v = oopDesc::decode_heap_oop(n); \ - } else { \ - v = *(oop*)index_oop_from_field_offset_long(p, offset); \ - } - // Get/SetObject must be special-cased, since it works with handles. @@ -192,7 +180,14 @@ // That is, it should be in the range [0, MAX_OBJECT_SIZE]. UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) UnsafeWrapper("Unsafe_GetObject"); - GET_OOP_FIELD(obj, offset, v) + oop p = JNIHandles::resolve(obj); + oop v; + if (UseCompressedOops) { + narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); + v = oopDesc::decode_heap_oop(n); + } else { + v = *(oop*)index_oop_from_field_offset_long(p, offset); + } jobject ret = JNIHandles::make_local(env, v); #if INCLUDE_ALL_GCS // We could be accessing the referent field in a reference @@ -261,6 +256,25 @@ OrderAccess::fence(); UNSAFE_END +UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) + UnsafeWrapper("Unsafe_GetUncompressedObject"); + oop v = *(oop*) (address) addr; + return JNIHandles::make_local(env, v); +UNSAFE_END + +UNSAFE_ENTRY(jclass, Unsafe_GetJavaMirror(JNIEnv *env, jobject unsafe, jlong metaspace_klass)) + UnsafeWrapper("Unsafe_GetJavaMirror"); + Klass* klass = (Klass*) (address) metaspace_klass; + return (jclass) JNIHandles::make_local(klass->java_mirror()); +UNSAFE_END + +UNSAFE_ENTRY(jlong, Unsafe_GetKlassPointer(JNIEnv *env, jobject unsafe, jobject obj)) + UnsafeWrapper("Unsafe_GetKlassPointer"); + oop o = JNIHandles::resolve(obj); + jlong klass = (jlong) (address) o->klass(); + return klass; +UNSAFE_END + #ifndef SUPPORTS_NATIVE_CX8 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'. @@ -1222,6 +1236,10 @@ {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"", FN_PTR(Unsafe_GetObjectVolatile)}, {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V", FN_PTR(Unsafe_SetObjectVolatile)}, + {CC"getUncompressedObject", CC"("ADR")"OBJ, FN_PTR(Unsafe_GetUncompressedObject)}, + {CC"getJavaMirror", CC"("ADR")"CLS, FN_PTR(Unsafe_GetJavaMirror)}, + {CC"getKlassPointer", CC"("OBJ")"ADR, FN_PTR(Unsafe_GetKlassPointer)}, + DECLARE_GETPUTOOP(Boolean, Z), DECLARE_GETPUTOOP(Byte, B), DECLARE_GETPUTOOP(Short, S), diff -r b39d2cec5056 -r 476c276de939 hotspot/test/runtime/Unsafe/GetKlassPointerGetJavaMirror.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/test/runtime/Unsafe/GetKlassPointerGetJavaMirror.java Mon Apr 27 09:02:41 2015 -0700 @@ -0,0 +1,46 @@ +/* + * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/* @test + * @bug 8022853 + * @library /testlibrary + * @modules java.base/sun.misc + * @run main GetKlassPointerGetJavaMirror + */ + +import static com.oracle.java.testlibrary.Asserts.*; + +import com.oracle.java.testlibrary.*; +import sun.misc.Unsafe; + +public class GetKlassPointerGetJavaMirror { + + public static void main(String args[]) throws Exception { + Unsafe unsafe = Utils.getUnsafe(); + Object o = new GetKlassPointerGetJavaMirror(); + final long metaspaceKlass = unsafe.getKlassPointer(o); + Class c = unsafe.getJavaMirror(metaspaceKlass); + assertEquals(o.getClass(), c); + } + +} diff -r b39d2cec5056 -r 476c276de939 hotspot/test/runtime/Unsafe/GetUncompressedObject.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/test/runtime/Unsafe/GetUncompressedObject.java Mon Apr 27 09:02:41 2015 -0700 @@ -0,0 +1,56 @@ +/* + * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/* @test + * @bug 8022853 + * @library /testlibrary + * @modules java.base/sun.misc + * @run main GetUncompressedObject + */ + +import static com.oracle.java.testlibrary.Asserts.*; + +import com.oracle.java.testlibrary.*; +import sun.misc.Unsafe; + +public class GetUncompressedObject { + + public static void main(String args[]) throws Exception { + Unsafe unsafe = Utils.getUnsafe(); + + // Allocate some memory and fill it with non-zero values. + final int size = 32; + final long address = unsafe.allocateMemory(size); + unsafe.setMemory(address, size, (byte) 0x23); + + // The only thing we can do is check for null-ness. + // So, store a null somewhere. + unsafe.putAddress(address + 16, 0); + + Object nullObj = unsafe.getUncompressedObject(address + 16); + if (nullObj != null) { + throw new InternalError("should be null"); + } + } + +}