/*
*
*
* Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program 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 program 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 at /legal/license.txt).
*
* 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 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.cldchi.jvm;
public class DebuggerInvoke {
private static final int T_BOOLEAN = 4;
private static final int T_CHAR = 5;
private static final int T_FLOAT = 6;
private static final int T_DOUBLE = 7;
private static final int T_BYTE = 8;
private static final int T_SHORT = 9;
private static final int T_INT = 10;
private static final int T_LONG = 11;
private static final int T_OBJECT = 12;
private static final int T_ARRAY = 13;
private static final int T_VOID = 14;
/**
* This method is used to synchronously invoke a method on
* behalf of a debugger and then return the method return value back
* to the debugger. The reason for this sync method is the
* non-synchronous nature of EntryActivations in the VM. Picture this,
* some event happens in the VM, like a breakpoint, which gets sent to
* the debugger. The debugger decides to invoke a Method. The return
* packet to the debugger for that invoke can't be sent until the Method
* returns and we send the return value (or exception object!) back to
* the debugger. So, all threads are suspended in the VM, we have
* a Method in hand and the debugger has picked a thread to execute this
* Method. We create an entry activation for that Method with all the
* args passed in by debugger. Then we create another entry activattion
* for this method. This allows us to synchronously call the Method
* requested, catch any exceptions and then call back down into the VM
* to send the reply packet. The return code in the VM will strip off
* these method calls from the thread stack so the thread will be back
* in the state it was before we started this whole invoke thing. We
* use two different return call methods based on what type of caller
* was on the stack when we started the whole invoke process. This is
* because there are two entry points into the VM; shared_call_vm and
* shared_call_vm_oop. (Don't care about shared_call_vm_exception). We
* need to make sure that the original call into the VM returns properly
* including any return values (object or otherwise) stored on the stack
* or in the EntryFrame or ThreadDesc.
*
* @param entry really an EntryActivation object from the VM
*
* @param transport a Transport object from the VM
*
* @param id debugger request id used to generate outgoing reply packet
*
* @param options invoke options from debugger
*
* @param return_type return type of Method being invoked
*
* @param is_obj_return if original caller of VM was shared_call_vm_oop
*
*/
private static void debuggerInvoke(Object entry, Object transport, int id,
int options, int return_type,
int is_obj_return)
{
try {
Object ret_obj = null;
switch (return_type) {
case T_VOID:
invokeV(entry);
break;
case T_OBJECT: {
Object[] ret = new Object[1];
Object o = invokeL(entry);
ret[0] = o;
ret_obj = ret;
break;
}
case T_BOOLEAN:
case T_BYTE:
case T_SHORT:
case T_CHAR:
case T_INT: {
int[] ret = new int[1];
switch (return_type) {
case T_BOOLEAN:
boolean b = invokeZ(entry);
ret[0] = b ? 1 : 0;
break;
case T_BYTE:
ret[0] = (int)invokeB(entry);
break;
case T_SHORT:
ret[0] = (int)invokeS(entry);
break;
case T_CHAR:
ret[0] = (int)invokeC(entry);
break;
case T_INT:
ret[0] = invokeI(entry);
break;
}
ret_obj = ret;
break;
}
case T_LONG: {
long[] ret = new long[1];
ret[0] = invokeJ(entry);
ret_obj = ret;
break;
}
case T_DOUBLE: {
double[] ret = new double[1];
ret[0] = invokeD(entry);
ret_obj = ret;
break;
}
case T_FLOAT: {
float[] ret = new float[1];
ret[0] = invokeF(entry);
ret_obj = ret;
break;
}
}
if (is_obj_return == 1) {
debuggerInvokeReturnObj(ret_obj, null, transport, id, options,
return_type);
} else {
debuggerInvokeReturn(ret_obj, null, transport, id, options,
return_type);
}
} catch (Throwable t) {
// we send the exception object to the debugger via the native call
if (is_obj_return == 1) {
debuggerInvokeReturnObj(null, t, transport, id, options,
return_type);
} else {
debuggerInvokeReturn(null, t, transport, id, options,
return_type);
}
}
}
/**
* This method is used by the java debugger code to signal the
* synchronous end of a method invoke
*/
private native static long debuggerInvokeReturn(Object ret,
Object exception,
Object transport,
int id,
int options,
int return_type);
/**
* You might think "Oh, I could combine this two methods into one
* and pass an arg to distinguish them". Don't! This one returns
* Object so that it enters the VM via shared_call_vm_oop. When
* we strip the frames off the stack in ObjectReferenceImpl::invoke_return
* we need to make sure we return the original return value that was
* stored in the EntryFrame back to the original caller.
*/
private native static Object debuggerInvokeReturnObj(Object ret,
Object exception,
Object transport,
int id,
int options,
int return_type);
private static native void invokeV(Object entry);
private static native boolean invokeZ(Object entry);
private static native char invokeC(Object entry);
private static native float invokeF(Object entry);
private static native double invokeD(Object entry);
private static native byte invokeB(Object entry);
private static native short invokeS(Object entry);
private static native int invokeI(Object entry);
private static native long invokeJ(Object entry);
private static native Object invokeL(Object entry);
}