// Begins stack walking.
//
// Parameters:
// stackStream StackStream object
// mode Stack walking mode.
// skip_frames Number of frames to be skipped.
// frame_count Number of frames to be traversed.
// start_index Start index to the user-supplied buffers.
// frames_array Buffer to store StackFrame in, starting at start_index.
// frames array is a Class<?>[] array when only getting caller
// reference, and a StackFrameInfo[] array (or derivative)
// otherwise. It should never be null.
//
// Returns Object returned from AbstractStackWalker::doStackWalk call.
//
oop StackWalk::walk(Handle stackStream, jlong mode,
int skip_frames, int frame_count, int start_index,
objArrayHandle frames_array,
TRAPS) {
ResourceMark rm(THREAD);
JavaThread* jt = (JavaThread*)THREAD;
log_debug(stackwalk)("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
mode, skip_frames, frame_count);
if (frames_array.is_null()) {
THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
}
// Setup traversal onto my stack.
if (live_frame_info(mode)) {
assert (use_frames_array(mode), "Bad mode for get live frame");
RegisterMap regMap(jt, true);
LiveFrameStream stream(jt, ®Map);
return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
start_index, frames_array, THREAD);
} else {
JavaFrameStream stream(jt, mode);
return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
start_index, frames_array, THREAD);
}
}
// Begins stack walking.
//
// Parameters:
// stackStream StackStream object
// mode Stack walking mode.
// skip_frames Number of frames to be skipped.
// frame_count Number of frames to be traversed.
// start_index Start index to the user-supplied buffers.
// frames_array Buffer to store StackFrame in, starting at start_index.
// frames array is a Class<?>[] array when only getting caller
// reference, and a StackFrameInfo[] array (or derivative)
// otherwise. It should never be null.
//
// Returns Object returned from AbstractStackWalker::doStackWalk call.
//
oop StackWalk::walk(Handle stackStream, jlong mode,
int skip_frames, int frame_count, int start_index,
objArrayHandle frames_array,
TRAPS) {
ResourceMark rm(THREAD);
JavaThread* jt = (JavaThread*)THREAD;
if (TraceStackWalk) {
tty->print_cr("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
mode, skip_frames, frame_count);
}
if (frames_array.is_null()) {
THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
}
Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
// Setup traversal onto my stack.
RegisterMap regMap(jt, true);
JavaFrameStream stream(jt, ®Map);
{
while (!stream.at_end()) {
InstanceKlass* ik = stream.method()->method_holder();
if (ik != stackWalker_klass &&
ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
break;
}
if (TraceStackWalk) {
tty->print(" skip "); stream.method()->print_short_name(); tty->print("\n");
}
stream.next();
}
// stack frame has been traversed individually and resume stack walk
// from the stack frame at depth == skip_frames.
for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
if (TraceStackWalk) {
tty->print(" skip "); stream.method()->print_short_name();
tty->print_cr(" frame id: " PTR_FORMAT " pc: " PTR_FORMAT,
p2i(stream.java_frame()->fr().id()),
p2i(stream.java_frame()->fr().pc()));
}
}
}
int end_index = start_index;
int numFrames = 0;
if (!stream.at_end()) {
numFrames = fill_in_frames(mode, stream, frame_count, start_index,
frames_array, end_index, CHECK_NULL);
if (numFrames < 1) {
THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
}
}
// JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
// Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
// which calls the implementation to consume the stack frames.
// When JVM_CallStackWalk returns, it invalidates the stack stream.
JavaValue result(T_OBJECT);
JavaCallArguments args(stackStream);
args.push_long(stream.address_value());
args.push_int(skip_frames);
args.push_int(frame_count);
args.push_int(start_index);
args.push_int(end_index);
// Link the thread and vframe stream into the callee-visible object
stream.setup_magic_on_entry(frames_array);
JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
// Do this before anything else happens, to disable any lingering stream objects
bool ok = stream.cleanup_magic_on_exit(frames_array);
// Throw pending exception if we must
(void) (CHECK_NULL);
if (!ok) {
THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
}
// Return normally
return (oop)result.get_jobject();
}
