Mercurial > hg > graal-jvmci-8
diff agent/src/share/classes/sun/jvm/hotspot/runtime/JNIHandleBlock.java @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | c18cbe5936b8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/JNIHandleBlock.java Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,154 @@ +/* + * Copyright 2000-2001 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +package sun.jvm.hotspot.runtime; + +import java.util.*; +import sun.jvm.hotspot.debugger.*; +import sun.jvm.hotspot.runtime.*; +import sun.jvm.hotspot.types.*; +import sun.jvm.hotspot.utilities.*; + +/** */ +public class JNIHandleBlock extends VMObject { + private static Field handlesField; + private static CIntegerField topField; + private static AddressField nextField; + + private static int blockSizeInOops; + + static { + VM.registerVMInitializedObserver(new Observer() { + public void update(Observable o, Object data) { + initialize(VM.getVM().getTypeDataBase()); + } + }); + } + + private static synchronized void initialize(TypeDataBase db) { + Type type = db.lookupType("JNIHandleBlock"); + + handlesField = type.getField("_handles"); + topField = type.getCIntegerField("_top"); + nextField = type.getAddressField("_next"); + + blockSizeInOops = db.lookupIntConstant("JNIHandleBlock::block_size_in_oops").intValue(); + } + + public JNIHandleBlock(Address addr) { + super(addr); + } + + public JNIHandleBlock next() { + Address handleAddr = nextField.getValue(addr); + if (handleAddr == null) { + return null; + } + + /* the next handle block is valid only if the current block is full */ + if (top() < blockSizeInOops) { + return null; + } + return new JNIHandleBlock(handleAddr); + } + + public int top() { + return (int) topField.getValue(addr); + } + + public void oopsDo(AddressVisitor visitor) { + // Visit handles in this block + for (int i = 0; i < top(); i++) { + Address cur = getOopHandleAddress(i); + if (cur != null) { + visitor.visitAddress(cur); + } + } + + // Visit handles in subsequent blocks if necessary + JNIHandleBlock n = next(); + if (n != null) { + n.oopsDo(visitor); + } + } + + public OopHandle getOopHandle(int x) { + Address oopAddr = getOopHandleAddress(x); + if (oopAddr != null) { + return oopAddr.getOopHandleAt(0); + } + return null; + } + + /** Debugging routine only. Returns non-null JNIHandleBlock + containing the JNI handle or null if this handle block and its + successors did not contain it (or if the handle was deleted). */ + public JNIHandleBlock blockContainingHandle(Address jniHandle) { + JNIHandleBlock cur = this; + while (cur != null) { + if (indexOfHandle(jniHandle) >= 0) { + return cur; + } + cur = cur.next(); + } + return null; + } + + /** Debugging routine: returns the index (0..top() - 1) of the + handle in this block, or -1 if the handle was not contained in + this block. Does not search successor blocks. */ + public int indexOfHandle(Address jniHandle) { + for (int i = 0; i < top(); i++) { + Address addr = getOopHandleAddress(i); + if (addr != null) { + if (addr.equals(jniHandle)) { + return i; + } + } + } + return -1; + } + + public String toString() { + Address handleBase = addr.addOffsetTo(handlesField.getOffset()); + Address handleEnd = addr.addOffsetTo(handlesField.getOffset() + top() * VM.getVM().getOopSize()); + return "JNIHandleBlock [" + handleBase + ", " + handleEnd + ")"; + } + + /** Only returns addresses of valid OopHandles */ + private Address getOopHandleAddress(int x) { + if (Assert.ASSERTS_ENABLED) { + Assert.that(x < top(), "out of bounds"); + } + + Address oopAddr = addr.addOffsetTo(handlesField.getOffset() + x * VM.getVM().getOopSize()); + OopHandle handle = oopAddr.getOopHandleAt(0); + if (VM.getVM().getUniverse().isInReserved(handle) && !VM.getVM().getJNIHandles().isDeletedHandle(handle)) { + /* the oop handle is valid only if it is not freed (i.e. reserved in heap) and is not a deleted oop */ + return oopAddr; + } else { + return null; + } + } +}