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package sun.jvm.hotspot.runtime;

import java.io.*;
import java.util.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.types.*;
import sun.jvm.hotspot.utilities.*;

This is an abstract class because there are certain OS- and CPU-specific operations (like the setting and getting of the last Java frame pointer) which need to be factored out. These operations are implemented by, for example, SolarisSPARCJavaThread, and the concrete subclasses are instantiated by the JavaThreadFactory in the Threads class.
/** This is an abstract class because there are certain OS- and CPU-specific operations (like the setting and getting of the last Java frame pointer) which need to be factored out. These operations are implemented by, for example, SolarisSPARCJavaThread, and the concrete subclasses are instantiated by the JavaThreadFactory in the Threads class. */
public class JavaThread extends Thread { private static final boolean DEBUG = System.getProperty("sun.jvm.hotspot.runtime.JavaThread.DEBUG") != null; private static AddressField nextField; private static sun.jvm.hotspot.types.OopField threadObjField; private static AddressField anchorField; private static AddressField lastJavaSPField; private static AddressField lastJavaPCField; private static CIntegerField threadStateField; private static AddressField osThreadField; private static AddressField stackBaseField; private static CIntegerField stackSizeField; private static CIntegerField terminatedField; private static JavaThreadPDAccess access; // JavaThreadStates read from underlying process private static int UNINITIALIZED; private static int NEW; private static int NEW_TRANS; private static int IN_NATIVE; private static int IN_NATIVE_TRANS; private static int IN_VM; private static int IN_VM_TRANS; private static int IN_JAVA; private static int IN_JAVA_TRANS; private static int BLOCKED; private static int BLOCKED_TRANS; private static int NOT_TERMINATED; private static int EXITING; private static final String ADDRESS_FORMAT = VM.getVM().isLP64() ? "0x%016x" : "0x%08x"; 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("JavaThread"); Type anchorType = db.lookupType("JavaFrameAnchor"); nextField = type.getAddressField("_next"); threadObjField = type.getOopField("_threadObj"); anchorField = type.getAddressField("_anchor"); lastJavaSPField = anchorType.getAddressField("_last_Java_sp"); lastJavaPCField = anchorType.getAddressField("_last_Java_pc"); threadStateField = type.getCIntegerField("_thread_state"); osThreadField = type.getAddressField("_osthread"); stackBaseField = type.getAddressField("_stack_base"); stackSizeField = type.getCIntegerField("_stack_size"); terminatedField = type.getCIntegerField("_terminated"); UNINITIALIZED = db.lookupIntConstant("_thread_uninitialized").intValue(); NEW = db.lookupIntConstant("_thread_new").intValue(); NEW_TRANS = db.lookupIntConstant("_thread_new_trans").intValue(); IN_NATIVE = db.lookupIntConstant("_thread_in_native").intValue(); IN_NATIVE_TRANS = db.lookupIntConstant("_thread_in_native_trans").intValue(); IN_VM = db.lookupIntConstant("_thread_in_vm").intValue(); IN_VM_TRANS = db.lookupIntConstant("_thread_in_vm_trans").intValue(); IN_JAVA = db.lookupIntConstant("_thread_in_Java").intValue(); IN_JAVA_TRANS = db.lookupIntConstant("_thread_in_Java_trans").intValue(); BLOCKED = db.lookupIntConstant("_thread_blocked").intValue(); BLOCKED_TRANS = db.lookupIntConstant("_thread_blocked_trans").intValue(); NOT_TERMINATED = db.lookupIntConstant("JavaThread::_not_terminated").intValue(); EXITING = db.lookupIntConstant("JavaThread::_thread_exiting").intValue(); } public JavaThread(Address addr) { super(addr); } void setThreadPDAccess(JavaThreadPDAccess access) { this.access = access; } public JavaThread next() { Address threadAddr = nextField.getValue(addr); if (threadAddr == null) { return null; } return VM.getVM().getThreads().createJavaThreadWrapper(threadAddr); }
NOTE: for convenience, this differs in definition from the underlying VM. Only "pure" JavaThreads return true; CompilerThreads, the CodeCacheSweeperThread, JVMDIDebuggerThreads return false. FIXME: consider encapsulating platform-specific functionality in an object instead of using inheritance (which is the primary reason we can't traverse CompilerThreads, etc; didn't want to have, for example, "SolarisSPARCCompilerThread".)
/** NOTE: for convenience, this differs in definition from the underlying VM. Only "pure" JavaThreads return true; CompilerThreads, the CodeCacheSweeperThread, JVMDIDebuggerThreads return false. FIXME: consider encapsulating platform-specific functionality in an object instead of using inheritance (which is the primary reason we can't traverse CompilerThreads, etc; didn't want to have, for example, "SolarisSPARCCompilerThread".) */
public boolean isJavaThread() { return true; } public boolean isExiting () { return (getTerminated() == EXITING) || isTerminated(); } public boolean isTerminated() { return (getTerminated() != NOT_TERMINATED) && (getTerminated() != EXITING); } public static AddressField getAnchorField() { return anchorField; }
Get the last Java stack pointer
/** Get the last Java stack pointer */
public Address getLastJavaSP() { Address sp = lastJavaSPField.getValue(addr.addOffsetTo(anchorField.getOffset())); return sp; } public Address getLastJavaPC() { Address pc = lastJavaPCField.getValue(addr.addOffsetTo(anchorField.getOffset())); return pc; }
Abstract accessor to last Java frame pointer, implemented by OS/CPU-specific JavaThread implementation. May return null if there is no frame pointer or if it is not necessary on this platform.
/** Abstract accessor to last Java frame pointer, implemented by OS/CPU-specific JavaThread implementation. May return null if there is no frame pointer or if it is not necessary on this platform. */
public Address getLastJavaFP(){ return access.getLastJavaFP(addr); } /** Abstract accessor to last Java pc, implemented by OS/CPU-specific JavaThread implementation. May return null if there is no frame pointer or if it is not necessary on this platform. */ /* public Address getLastJavaPC(){ return access.getLastJavaPC(addr); } */ // FIXME: not yet implementable // public abstract void setLastJavaFP(Address fp);
A stack pointer older than any java frame stack pointer. Only needed on some platforms; for example, see thread_solaris_sparc.hpp.
/** A stack pointer older than any java frame stack pointer. Only needed on some platforms; for example, see thread_solaris_sparc.hpp. */
public Address getBaseOfStackPointer(){ return access.getBaseOfStackPointer(addr); } // FIXME: not yet implementable // public abstract void setBaseOfStackPointer(Address fp);
Tells whether the last Java frame is set
/** Tells whether the last Java frame is set */
public boolean hasLastJavaFrame() { return (getLastJavaSP() != null); }
Accessing frames
/** Accessing frames */
public Frame getLastFrame() { // FIXME: would need to implement runtime routine // "cacheStatePD(boolean)" for reflective system to be able to // flush register windows on SPARC return cookLastFrame(getLastFramePD()); }
Internal routine implemented by platform-dependent subclasses
/** Internal routine implemented by platform-dependent subclasses */
protected Frame getLastFramePD(){ return access.getLastFramePD(this, addr); }
Accessing frames. Returns the last Java VFrame or null if none was present. (NOTE that this is mostly unusable in a debugging system; see getLastJavaVFrameDbg, below, which provides very different functionality.)
/** Accessing frames. Returns the last Java VFrame or null if none was present. (NOTE that this is mostly unusable in a debugging system; see getLastJavaVFrameDbg, below, which provides very different functionality.) */
public JavaVFrame getLastJavaVFrame(RegisterMap regMap) { if (Assert.ASSERTS_ENABLED) { Assert.that(regMap != null, "a map must be given"); } Frame f = getLastFrame(); if (f == null) { return null; } for (VFrame vf = VFrame.newVFrame(f, regMap, this); vf != null; vf = vf.sender()) { if (vf.isJavaFrame()) { return (JavaVFrame) vf; } } return null; }
This should only be used by a debugger. Uses the current frame guess to attempt to get the topmost JavaVFrame. (getLastJavaVFrame, as a port of the VM's routine, assumes the VM is at a safepoint.)
/** This should only be used by a debugger. Uses the current frame guess to attempt to get the topmost JavaVFrame. (getLastJavaVFrame, as a port of the VM's routine, assumes the VM is at a safepoint.) */
public JavaVFrame getLastJavaVFrameDbg() { RegisterMap regMap = newRegisterMap(true); sun.jvm.hotspot.runtime.Frame f = getCurrentFrameGuess(); if (f == null) return null; boolean imprecise = true; if (f.isInterpretedFrame() && !f.isInterpretedFrameValid()) { if (DEBUG) { System.out.println("Correcting for invalid interpreter frame"); } f = f.sender(regMap); imprecise = false; } VFrame vf = VFrame.newVFrame(f, regMap, this, true, imprecise); if (vf == null) { if (DEBUG) { System.out.println(" (Unable to create vframe for topmost frame guess)"); } return null; } return vf.isJavaFrame() ? (JavaVFrame)vf : vf.javaSender(); }
In this system, a JavaThread is the top-level factory for a RegisterMap, since the JavaThread implementation is already platform-specific and RegisterMap is also necessarily platform-specific. The updateMap argument indicates whether the register map needs to be updated, for example during stack traversal -- see frame.hpp.
/** In this system, a JavaThread is the top-level factory for a RegisterMap, since the JavaThread implementation is already platform-specific and RegisterMap is also necessarily platform-specific. The updateMap argument indicates whether the register map needs to be updated, for example during stack traversal -- see frame.hpp. */
public RegisterMap newRegisterMap(boolean updateMap){ return access.newRegisterMap(this, updateMap); }
This is only designed to be used by the debugging system. Returns a "best guess" of the topmost frame on the stack. This guess should be as "raw" as possible. For example, if the topmost frame is an interpreter frame (the return PC is in the interpreter) but is not a valid frame (i.e., the BCI has not yet been set up) this should still return the topmost frame and not the sender. Validity checks are done at higher levels.
/** This is only designed to be used by the debugging system. Returns a "best guess" of the topmost frame on the stack. This guess should be as "raw" as possible. For example, if the topmost frame is an interpreter frame (the return PC is in the interpreter) but is not a valid frame (i.e., the BCI has not yet been set up) this should still return the topmost frame and not the sender. Validity checks are done at higher levels. */
public Frame getCurrentFrameGuess(){ return access.getCurrentFrameGuess(this, addr); }
Also only intended for use by the debugging system. Provides the same effect of OSThread::print(); that is, prints a value which allows the user to intuitively understand which native OS thread maps to this Java thread. Does not print a newline or leading or trailing spaces.
/** Also only intended for use by the debugging system. Provides the same effect of OSThread::print(); that is, prints a value which allows the user to intuitively understand which native OS thread maps to this Java thread. Does not print a newline or leading or trailing spaces. */
public void printThreadIDOn(PrintStream tty) { access.printThreadIDOn(addr,tty); } public void printThreadID() { printThreadIDOn(System.out); } public ThreadProxy getThreadProxy() { return access.getThreadProxy(addr); } // // Safepoint support // public JavaThreadState getThreadState() { int val = (int) threadStateField.getValue(addr); if (val == UNINITIALIZED) { return JavaThreadState.UNINITIALIZED; } else if (val == NEW) { return JavaThreadState.NEW; } else if (val == NEW_TRANS) { return JavaThreadState.NEW_TRANS; } else if (val == IN_NATIVE) { return JavaThreadState.IN_NATIVE; } else if (val == IN_NATIVE_TRANS) { return JavaThreadState.IN_NATIVE_TRANS; } else if (val == IN_VM) { return JavaThreadState.IN_VM; } else if (val == IN_VM_TRANS) { return JavaThreadState.IN_VM_TRANS; } else if (val == IN_JAVA) { return JavaThreadState.IN_JAVA; } else if (val == IN_JAVA_TRANS) { return JavaThreadState.IN_JAVA_TRANS; } else if (val == BLOCKED) { return JavaThreadState.BLOCKED; } else if (val == BLOCKED_TRANS) { return JavaThreadState.BLOCKED_TRANS; } else { throw new RuntimeException("Illegal thread state " + val); } } // FIXME: not yet implementable // public void setThreadState(JavaThreadState s); // // Miscellaneous operations // public OSThread getOSThread() { return (OSThread) VMObjectFactory.newObject(OSThread.class, osThreadField.getValue(addr)); } public Address getStackBase() { return stackBaseField.getValue(addr); } public long getStackBaseValue() { return VM.getVM().getAddressValue(getStackBase()); } public long getStackSize() { return stackSizeField.getValue(addr); } public int getTerminated() { return (int) terminatedField.getValue(addr); }
Gets the Java-side thread object for this JavaThread
/** Gets the Java-side thread object for this JavaThread */
public Oop getThreadObj() { Oop obj = null; try { obj = VM.getVM().getObjectHeap().newOop(threadObjField.getValue(addr)); } catch (Exception e) { e.printStackTrace(); } return obj; }
Get the Java-side name of this thread
/** Get the Java-side name of this thread */
public String getThreadName() { Oop threadObj = getThreadObj(); if (threadObj == null) { return "<null>"; } return OopUtilities.threadOopGetName(threadObj); } // // Oop traversal // public void oopsDo(AddressVisitor oopVisitor) { super.oopsDo(oopVisitor); // FIXME: add in the rest of the routine from the VM // Traverse the execution stack for(StackFrameStream fst = new StackFrameStream(this); !fst.isDone(); fst.next()) { fst.getCurrent().oopsDo(oopVisitor, fst.getRegisterMap()); } } public boolean isInStack(Address a) { if (Assert.ASSERTS_ENABLED) { Assert.that(VM.getVM().isDebugging(), "Not yet implemented for non-debugging system"); } Address sp = lastSPDbg(); Address stackBase = getStackBase(); // Be robust if (sp == null) return false; return stackBase.greaterThan(a) && sp.lessThanOrEqual(a); } public boolean isLockOwned(Address a) { Address stackBase = getStackBase(); Address stackLimit = stackBase.addOffsetTo(-getStackSize()); return stackBase.greaterThan(a) && stackLimit.lessThanOrEqual(a); // FIXME: should traverse MonitorArray/MonitorChunks as in VM } public Oop getCurrentParkBlocker() { Oop threadObj = getThreadObj(); if (threadObj != null) { return OopUtilities.threadOopGetParkBlocker(threadObj); } return null; } public void printInfoOn(PrintStream tty) { tty.println("State: " + getThreadState().toString()); // Attempt to figure out the addresses covered by Java frames. // NOTE: we should make this a method and let the Stackwalk panel use the result too. // sun.jvm.hotspot.runtime.Frame tmpFrame = getCurrentFrameGuess(); if (tmpFrame != null ) { Address sp = tmpFrame.getSP(); Address maxSP = sp; Address minSP = sp; RegisterMap tmpMap = newRegisterMap(false); while ((tmpFrame != null) && (!tmpFrame.isFirstFrame())) { tmpFrame = tmpFrame.sender(tmpMap); if (tmpFrame != null) { sp = tmpFrame.getSP(); maxSP = AddressOps.max(maxSP, sp); minSP = AddressOps.min(minSP, sp); } } tty.println("Stack in use by Java: " + minSP + " .. " + maxSP); } else { tty.println("No Java frames present"); } tty.println("Base of Stack: " + getStackBase()); tty.println("Last_Java_SP: " + getLastJavaSP()); tty.println("Last_Java_FP: " + getLastJavaFP()); tty.println("Last_Java_PC: " + getLastJavaPC()); // More stuff like saved_execption_pc, safepoint_state, ... access.printInfoOn(addr, tty); } /////////////////////////////// // // // FIXME: add more accessors // // // /////////////////////////////// //-------------------------------------------------------------------------------- // Internals only below this point // private Frame cookLastFrame(Frame fr) { if (fr == null) { return null; } Address pc = fr.getPC(); if (Assert.ASSERTS_ENABLED) { if (pc == null) { Assert.that(VM.getVM().isDebugging(), "must have PC"); } } return fr; } private Address lastSPDbg() { return access.getLastSP(addr); } public void printThreadInfoOn(PrintStream out){ Oop threadOop = this.getThreadObj(); out.print("\""); out.print(this.getThreadName()); out.print("\" #"); out.print(OopUtilities.threadOopGetTID(threadOop)); if(OopUtilities.threadOopGetDaemon(threadOop)){ out.print(" daemon"); } out.print(" prio="); out.print(OopUtilities.threadOopGetPriority(threadOop)); out.print(" tid="); out.print(this.getAddress()); out.print(" nid="); out.print(String.format("0x%x ",this.getOSThread().threadId())); out.print(getOSThread().getThreadState().getPrintVal()); out.print(" ["); if(this.getLastJavaSP() == null){ out.print(String.format(ADDRESS_FORMAT,0L)); } else { out.print(this.getLastJavaSP().andWithMask(~0xFFF)); } out.println("]"); out.print(" java.lang.Thread.State: "); out.println(OopUtilities.threadOopGetThreadStatusName(threadOop)); out.print(" JavaThread state: _thread_"); out.println(this.getThreadState().toString().toLowerCase()); } }