private HeapRegion at(long index) {
Address arrayAddr = regionsField.getValue(addr);
// Offset of &_region[index]
long offset = index * VM.getVM().getAddressSize();
Address regionAddr = arrayAddr.getAddressAt(offset);
return (HeapRegion) VMObjectFactory.newObject(HeapRegion.class, regionAddr);
}
public OopHandle getOopHandle(int x) {
Address oopAddr = getOopHandleAddress(x);
if (oopAddr != null) {
return oopAddr.getOopHandleAt(0);
}
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 ThreadProxy getThreadProxy(Address addr) {
// Addr is the address of the JavaThread.
// Fetch the OSThread (for now and for simplicity, not making a
// separate "OSThread" class in this package)
Address osThreadAddr = osThreadField.getValue(addr);
// Get the address of the _thread_id from the OSThread
Address threadIdAddr = osThreadAddr.addOffsetTo(osThreadThreadIDField.getOffset());
JVMDebugger debugger = VM.getVM().getDebugger();
return debugger.getThreadForIdentifierAddress(threadIdAddr);
}
void setValue(String value) throws DebuggerException {
try {
byte[] data = value.getBytes("US-ASCII");
if (data.length >= bufLen) {
throw new DebuggerException("String too long");
}
for (int i = 0; i < data.length; i++) {
addr.setCIntegerAt(i, 1, data[i]);
}
addr.setCIntegerAt(data.length, 1, 0);
} catch (UnsupportedEncodingException e) {
throw new DebuggerException("Unable to use US-ASCII encoding");
}
}
String getValue() throws DebuggerException {
int len = 0;
while ((addr.getCIntegerAt(len, 1, true) != 0) && (len < bufLen)) {
++len;
}
byte[] res = new byte[len];
for (int i = 0; i < len; i++) {
res[i] = (byte) addr.getCIntegerAt(i, 1, true);
}
try {
return new String(res, "US-ASCII");
} catch (UnsupportedEncodingException e) {
throw new DebuggerException("Unable to use US-ASCII encoding");
}
}
public CFrame sender() {
if (ebp == null) {
return null;
}
Address nextEBP = ebp.getAddressAt(0 * ADDRESS_SIZE);
if (nextEBP == null) {
return null;
}
Address nextPC = ebp.getAddressAt(1 * ADDRESS_SIZE);
if (nextPC == null) {
return null;
}
return new X86CFrame(dbg(), nextEBP, nextPC);
}
/** 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;
}
}
public LoadObject loadObjectContainingPC(Address pc) throws DebuggerException {
if (pc == null) {
return null;
}
List objs = getLoadObjectList();
Object[] arr = objs.toArray();
// load objects are sorted by base address, do binary search
int mid = -1;
int low = 0;
int high = arr.length - 1;
while (low <= high) {
mid = (low + high) >> 1;
LoadObject midVal = (LoadObject) arr[mid];
long cmp = pc.minus(midVal.getBase());
if (cmp < 0) {
high = mid - 1;
} else if (cmp > 0) {
long size = midVal.getSize();
if (cmp >= size) {
low = mid + 1;
} else {
return (LoadObject) arr[mid];
}
} else { // match found
return (LoadObject) arr[mid];
}
}
// no match found.
return null;
}
public void visitCompOopAddress(Address addr) {
Oop next = heap.newOop(addr.getCompOopHandleAt(0));
LivenessPathElement lp =
new LivenessPathElement(
null, new NamedFieldIdentifier(baseRootDescription + " @ " + addr));
rp.put(lp, next);
markAndTraverse(next);
}
public DbxSPARCThread(DbxDebugger debugger, Address addr) {
this.debugger = debugger;
// FIXME: the size here should be configurable. However, making it
// so would produce a dependency on the "types" package from the
// debugger package, which is not desired.
this.id = (int) addr.getCIntegerAt(0, 4, true);
}
private String addressToString(Address a) {
if (a == null) {
if (is64Bit) {
return "0x0000000000000000";
} else {
return "0x00000000";
}
}
return a.toString();
}
// refer to Threads::owning_thread_from_monitor_owner
public JavaThread owningThreadFromMonitor(Address o) {
if (o == null) return null;
for (JavaThread thread = first(); thread != null; thread = thread.next()) {
if (o.equals(thread.threadObjectAddress())) {
return thread;
}
}
for (JavaThread thread = first(); thread != null; thread = thread.next()) {
if (thread.isLockOwned(o)) return thread;
}
return null;
}
/** Returns false if not able to find a frame within a reasonable range. */
public boolean run(long regionInBytesToSearch) {
Address sp = context.getRegisterAsAddress(AMD64ThreadContext.RSP);
Address pc = context.getRegisterAsAddress(AMD64ThreadContext.RIP);
Address fp = context.getRegisterAsAddress(AMD64ThreadContext.RBP);
if (sp == null) {
// Bail out if no last java frame either
if (thread.getLastJavaSP() != null) {
setValues(thread.getLastJavaSP(), thread.getLastJavaFP(), null);
return true;
}
return false;
}
Address end = sp.addOffsetTo(regionInBytesToSearch);
VM vm = VM.getVM();
setValues(null, null, null); // Assume we're not going to find anything
if (vm.isJavaPCDbg(pc)) {
if (vm.isClientCompiler()) {
// If the topmost frame is a Java frame, we are (pretty much)
// guaranteed to have a viable EBP. We should be more robust
// than this (we have the potential for losing entire threads'
// stack traces) but need to see how much work we really have
// to do here. Searching the stack for an (SP, FP) pair is
// hard since it's easy to misinterpret inter-frame stack
// pointers as base-of-frame pointers; we also don't know the
// sizes of C1 frames (not registered in the nmethod) so can't
// derive them from ESP.
setValues(sp, fp, pc);
return true;
} else {
if (vm.getInterpreter().contains(pc)) {
if (DEBUG) {
System.out.println(
"CurrentFrameGuess: choosing interpreter frame: sp = "
+ sp
+ ", fp = "
+ fp
+ ", pc = "
+ pc);
}
setValues(sp, fp, pc);
return true;
}
// For the server compiler, EBP is not guaranteed to be valid
// for compiled code. In addition, an earlier attempt at a
// non-searching algorithm (see below) failed because the
// stack pointer from the thread context was pointing
// (considerably) beyond the ostensible end of the stack, into
// garbage; walking from the topmost frame back caused a crash.
//
// This algorithm takes the current PC as a given and tries to
// find the correct corresponding SP by walking up the stack
// and repeatedly performing stackwalks (very inefficient).
//
// FIXME: there is something wrong with stackwalking across
// adapter frames...this is likely to be the root cause of the
// failure with the simpler algorithm below.
for (long offset = 0; offset < regionInBytesToSearch; offset += vm.getAddressSize()) {
try {
Address curSP = sp.addOffsetTo(offset);
Frame frame = new X86Frame(curSP, null, pc);
RegisterMap map = thread.newRegisterMap(false);
while (frame != null) {
if (frame.isEntryFrame() && frame.entryFrameIsFirst()) {
// We were able to traverse all the way to the
// bottommost Java frame.
// This sp looks good. Keep it.
if (DEBUG) {
System.out.println("CurrentFrameGuess: Choosing sp = " + curSP + ", pc = " + pc);
}
setValues(curSP, null, pc);
return true;
}
frame = frame.sender(map);
}
} catch (Exception e) {
if (DEBUG) {
System.out.println("CurrentFrameGuess: Exception " + e + " at offset " + offset);
}
// Bad SP. Try another.
}
}
// Were not able to find a plausible SP to go with this PC.
// Bail out.
return false;
/*
// Original algorithm which does not work because SP was
// pointing beyond where it should have:
// For the server compiler, EBP is not guaranteed to be valid
// for compiled code. We see whether the PC is in the
// interpreter and take care of that, otherwise we run code
// (unfortunately) duplicated from AMD64Frame.senderForCompiledFrame.
CodeCache cc = vm.getCodeCache();
if (cc.contains(pc)) {
CodeBlob cb = cc.findBlob(pc);
// See if we can derive a frame pointer from SP and PC
// NOTE: This is the code duplicated from AMD64Frame
Address saved_fp = null;
int llink_offset = cb.getLinkOffset();
if (llink_offset >= 0) {
// Restore base-pointer, since next frame might be an interpreter frame.
Address fp_addr = sp.addOffsetTo(VM.getVM().getAddressSize() * llink_offset);
saved_fp = fp_addr.getAddressAt(0);
}
setValues(sp, saved_fp, pc);
return true;
}
*/
}
} else {
// If the current program counter was not known to us as a Java
// PC, we currently assume that we are in the run-time system
// and attempt to look to thread-local storage for saved ESP and
// EBP. Note that if these are null (because we were, in fact,
// in Java code, i.e., vtable stubs or similar, and the SA
// didn't have enough insight into the target VM to understand
// that) then we are going to lose the entire stack trace for
// the thread, which is sub-optimal. FIXME.
if (DEBUG) {
System.out.println(
"CurrentFrameGuess: choosing last Java frame: sp = "
+ thread.getLastJavaSP()
+ ", fp = "
+ thread.getLastJavaFP());
}
if (thread.getLastJavaSP() == null) {
return false; // No known Java frames on stack
}
setValues(thread.getLastJavaSP(), thread.getLastJavaFP(), null);
return true;
}
}
public int regEncode() {
if (matcherRegEncodeAddr != null) {
return (int) matcherRegEncodeAddr.getCIntegerAt(value, 1, true);
}
return value;
}
public void set_map(Address addr) {
for (int i = 0; i < sizeInWords(); i++) {
data[i] = (int) addr.getCIntegerAt(0, bytesPerWord, true);
addr = addr.addOffsetTo(bytesPerWord);
}
}
public Address getLastJavaFP(Address addr) {
return lastJavaFPField.getValue(
addr.addOffsetTo(sun.jvm.hotspot.runtime.JavaThread.getAnchorField().getOffset()));
}
