| /* |
| * Copyright (c) 2000, 2008, 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. |
| * |
| */ |
| |
| package sun.jvm.hotspot.debugger; |
| |
| /** <P> This is the bottom-most interface which abstracts address |
| access for both debugging and introspection. In the situation of |
| debugging a target VM, these routines can throw the specified |
| RuntimeExceptions to indicate failure and allow recovery of the |
| debugging system. If these are used for introspecting the current |
| VM and implementing functionality in it, however, it is expected |
| that these kinds of failures will not occur and, in fact, a crash |
| will occur if the situation arises where they would have been |
| thrown. </P> |
| |
| <P> Addresses are immutable. Further, it was decided not to expose |
| the representation of the Address (and provide a corresponding |
| factory method from, for example, long to Address). Unfortunately, |
| because of the existence of C and "reuse" of low bits of pointers, |
| it is occasionally necessary to perform logical operations like |
| masking off the low bits of an "address". While these operations |
| could be used to generate arbitrary Address objects, allowing this |
| is not the intent of providing these operations. </P> |
| |
| <P> This interface is able to fetch all Java primitive types, |
| addresses, oops, and C integers of arbitrary size (see @see |
| sun.jvm.hotspot.types.CIntegerType for further discussion). Note |
| that the result of the latter is restricted to fitting into a |
| 64-bit value and the high-order bytes will be silently discarded |
| if too many bytes are requested. </P> |
| |
| <P> Implementations may have restrictions, for example that the |
| Java-related routines may not be called until a certain point in |
| the bootstrapping process once the sizes of the Java primitive |
| types are known. (The current implementation has that property.) |
| </P> |
| |
| <P> A note of warning: in C addresses, when represented as |
| integers, are usually represented with unsigned types. |
| Unfortunately, there are no unsigned primitive types in Java, so |
| care will have to be taken in the implementation of this interface |
| if using longs as the representation for 64-bit correctness. This |
| is not so simple for the comparison operators. </P> */ |
| |
| public interface Address { |
| |
| /** This is stated explicitly here because it is important for |
| implementations to understand that equals() and hashCode() must |
| absolutely, positively work properly -- i.e., two Address |
| objects representing the same address are both equal (via |
| equals()) and have the same hash code. */ |
| public boolean equals(Object arg); |
| |
| /** This is stated explicitly here because it is important for |
| implementations to understand that equals() and hashCode() must |
| absolutely, positively work properly -- i.e., two Address |
| objects representing the same address are both equal (via |
| equals()) and have the same hash code. */ |
| public int hashCode(); |
| |
| // |
| // C/C++-related routines |
| // |
| |
| public long getCIntegerAt (long offset, long numBytes, boolean isUnsigned) |
| throws UnmappedAddressException, UnalignedAddressException; |
| /** This returns null if the address at the given offset is NULL. */ |
| public Address getAddressAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| /** Returns the decoded address at the given offset */ |
| public Address getCompOopAddressAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public Address getCompKlassAddressAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| |
| // |
| // Java-related routines |
| // |
| |
| public boolean getJBooleanAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public byte getJByteAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public char getJCharAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public double getJDoubleAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public float getJFloatAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public int getJIntAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public long getJLongAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| public short getJShortAt (long offset) throws UnmappedAddressException, UnalignedAddressException; |
| /** This returns null if the address at the given offset is NULL. */ |
| public OopHandle getOopHandleAt (long offset) |
| throws UnmappedAddressException, UnalignedAddressException, NotInHeapException; |
| public OopHandle getCompOopHandleAt (long offset) |
| throws UnmappedAddressException, UnalignedAddressException, NotInHeapException; |
| |
| // |
| // C/C++-related mutators. These throw UnmappedAddressException if |
| // the target is read-only (for example, a core file rather than an |
| // active process), if the target address is unmapped, or if it is |
| // read-only. The implementation may supply extra detail messages. |
| // |
| |
| /** Sets a C integer numBytes in size at the specified offset. Note |
| that there is no "unsigned" flag for the accessor since the |
| value will not be sign-extended; the number of bytes are simply |
| copied from the value into the target address space. */ |
| public void setCIntegerAt(long offset, long numBytes, long value); |
| |
| /** Sets an Address at the specified location. */ |
| public void setAddressAt(long offset, Address value); |
| |
| // |
| // Java-related mutators -- see above. |
| // |
| |
| public void setJBooleanAt (long offset, boolean value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setJByteAt (long offset, byte value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setJCharAt (long offset, char value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setJDoubleAt (long offset, double value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setJFloatAt (long offset, float value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setJIntAt (long offset, int value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setJLongAt (long offset, long value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setJShortAt (long offset, short value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| public void setOopHandleAt (long offset, OopHandle value) |
| throws UnmappedAddressException, UnalignedAddressException; |
| |
| // |
| // Arithmetic operations -- necessary evil. |
| // |
| |
| /** This throws an UnsupportedOperationException if this address happens |
| to actually be an OopHandle, because interior object pointers |
| are not allowed. Negative offsets are allowed and handle the |
| subtraction case. */ |
| public Address addOffsetTo (long offset) throws UnsupportedOperationException; |
| |
| /** This method had to be added in order to support heap iteration |
| in the debugging system, and is effectively the dangerous |
| operation of allowing interior object pointers. For this reason |
| it was kept as a separate API and its use is forbidden in the |
| non-debugging (i.e., reflective system) case. It is strongly |
| recommended that this not be called by clients: it is currently |
| wrapped up in the Space's iteration mechanism. */ |
| public OopHandle addOffsetToAsOopHandle(long offset) throws UnsupportedOperationException; |
| |
| /** Performs the subtraction "this - arg", returning the resulting |
| offset in bytes. Note that this must handle a null argument |
| properly, and can be used to convert an Address into a long for |
| further manipulation, but that the reverse conversion is not |
| possible. (FIXME: any signed/unsigned issues? Should this work |
| for OopHandles?) */ |
| public long minus(Address arg); |
| |
| /** Performs unsigned comparison "this < arg". |
| (FIXME: should this work for OopHandles?) */ |
| public boolean lessThan (Address arg); |
| /** Performs unsigned comparison "this <= arg". |
| (FIXME: should this work for OopHandles?) */ |
| public boolean lessThanOrEqual (Address arg); |
| /** Performs unsigned comparison "this > arg". |
| (FIXME: should this work for OopHandles?) */ |
| public boolean greaterThan (Address arg); |
| /** Performs unsigned comparison "this >= arg". |
| (FIXME: should this work for OopHandles?) */ |
| public boolean greaterThanOrEqual(Address arg); |
| |
| /** This throws an UnsupportedOperationException if this address happens |
| to actually be an OopHandle. Performs a logical "and" operation |
| of the bits of the address and the mask (least significant bits |
| of the Address and the mask are aligned) and returns the result |
| as an Address. Returns null if the result was zero. */ |
| public Address andWithMask(long mask) throws UnsupportedOperationException; |
| |
| /** This throws an UnsupportedOperationException if this address happens |
| to actually be an OopHandle. Performs a logical "or" operation |
| of the bits of the address and the mask (least significant bits |
| of the Address and the mask are aligned) and returns the result |
| as an Address. Returns null if the result was zero. */ |
| public Address orWithMask(long mask) throws UnsupportedOperationException; |
| |
| /** This throws an UnsupportedOperationException if this address happens |
| to actually be an OopHandle. Performs a logical "exclusive or" |
| operation of the bits of the address and the mask (least |
| significant bits of the Address and the mask are aligned) and |
| returns the result as an Address. Returns null if the result was |
| zero. */ |
| public Address xorWithMask(long mask) throws UnsupportedOperationException; |
| |
| // return address as long integer. |
| public long asLongValue(); |
| } |