public OopHandle getOopHandle(int x) {
   Address oopAddr = getOopHandleAddress(x);
   if (oopAddr != null) {
     return oopAddr.getOopHandleAt(0);
   }
   return null;
 }
Ejemplo n.º 2
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  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);
  }
 /**
  * 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;
 }
  /** 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;
    }
  }
Ejemplo n.º 5
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 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);
 }
Ejemplo n.º 6
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 public Address getLastJavaFP(Address addr) {
   return lastJavaFPField.getValue(
       addr.addOffsetTo(sun.jvm.hotspot.runtime.JavaThread.getAnchorField().getOffset()));
 }
  /** 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;
    }
  }