com.oracle.svm.core.stack

Class JavaStackWalker

java.lang.Object

com.oracle.svm.core.stack.JavaStackWalker

public final class JavaStackWalker
extends Object

Provides methods to iterate each of the Java frames in a thread stack. It skips native frames, i.e., it only visits frames where Java frame information is available.

For most cases, the "walk*" methods that apply a StackFrameVisitor are the preferred way to do stack walking. Use cases that are extremely performance sensitive, or cannot use a visitor approach, can use the various "init*" and "continue*" methods directly.

The stack walking code must be allocation free (so that it can be used during garbage collection) and not use static state (so that multiple threads can walk their stacks concurrently). State is therefore stored in a stack-allocated JavaStackWalk structure.

Method Summary

Modifier and Type	Method and Description
static boolean	continueWalk(JavaStackWalk walk, CodeInfo info) Continue a started stack walk.
static boolean	continueWalk(JavaStackWalk walk, SimpleCodeInfoQueryResult queryResult, DeoptimizedFrame deoptFrame)
static boolean	initWalk(JavaStackWalk walk, org.graalvm.nativeimage.IsolateThread thread) Initialize a stack walk for the given thread.
static void	initWalk(JavaStackWalk walk, org.graalvm.word.Pointer startSP) See JavaStackWalker.initWalk(JavaStackWalk, Pointer, CodePointer), except that the instruction pointer will be read from the stack later on.
static void	initWalk(JavaStackWalk walk, org.graalvm.word.Pointer startSP, org.graalvm.nativeimage.c.function.CodePointer startIP) Initialize a stack walk for the current thread.
static RuntimeException	reportUnknownFrameEncountered(org.graalvm.word.Pointer sp, org.graalvm.nativeimage.c.function.CodePointer ip, DeoptimizedFrame deoptFrame)
static <T> boolean	walkCurrentThread(org.graalvm.word.Pointer startSP, ParameterizedStackFrameVisitor<T> visitor, T data)
static boolean	walkCurrentThread(org.graalvm.word.Pointer startSP, StackFrameVisitor visitor)
static <T> boolean	walkThread(org.graalvm.nativeimage.IsolateThread thread, ParameterizedStackFrameVisitor<T> visitor, T data)
static boolean	walkThread(org.graalvm.nativeimage.IsolateThread thread, StackFrameVisitor visitor)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

initWalk

public static void initWalk(JavaStackWalk walk,
                            org.graalvm.word.Pointer startSP,
                            org.graalvm.nativeimage.c.function.CodePointer startIP)

Initialize a stack walk for the current thread. The given walk parameter should normally be allocated on the stack.

The stack walker is only valid while the stack being walked is stable and existent.

Parameters:

walk - the stack-allocated walk base pointer

startSP - the starting SP

startIP - the starting IP

initWalk

public static void initWalk(JavaStackWalk walk,
                            org.graalvm.word.Pointer startSP)

See JavaStackWalker.initWalk(JavaStackWalk, Pointer, CodePointer), except that the instruction pointer will be read from the stack later on.

initWalk

public static boolean initWalk(JavaStackWalk walk,
                               org.graalvm.nativeimage.IsolateThread thread)

Initialize a stack walk for the given thread. The given walk parameter should normally be allocated on the stack.

Parameters:

walk - the stack-allocated walk base pointer

thread - the thread to examine

continueWalk

public static boolean continueWalk(JavaStackWalk walk,
                                   CodeInfo info)

Continue a started stack walk. This method must only be called after JavaStackWalker.initWalk(com.oracle.svm.core.stack.JavaStackWalk, org.graalvm.word.Pointer, org.graalvm.nativeimage.c.function.CodePointer) was called to start the walk. Once this method returns false, it will always return false.

Parameters:

walk - the initiated stack walk pointer

Returns:

true if there is another frame, or false if there are no more frames to iterate

continueWalk

public static boolean continueWalk(JavaStackWalk walk,
                                   SimpleCodeInfoQueryResult queryResult,
                                   DeoptimizedFrame deoptFrame)

reportUnknownFrameEncountered

public static RuntimeException reportUnknownFrameEncountered(org.graalvm.word.Pointer sp,
                                                             org.graalvm.nativeimage.c.function.CodePointer ip,
                                                             DeoptimizedFrame deoptFrame)

walkCurrentThread

public static boolean walkCurrentThread(org.graalvm.word.Pointer startSP,
                                        StackFrameVisitor visitor)

walkCurrentThread

public static <T> boolean walkCurrentThread(org.graalvm.word.Pointer startSP,
                                            ParameterizedStackFrameVisitor<T> visitor,
                                            T data)

walkThread

public static boolean walkThread(org.graalvm.nativeimage.IsolateThread thread,
                                 StackFrameVisitor visitor)

walkThread

public static <T> boolean walkThread(org.graalvm.nativeimage.IsolateThread thread,
                                     ParameterizedStackFrameVisitor<T> visitor,
                                     T data)