// Unpacks one or more frames into user-supplied buffers.
// Updates the end index, and returns the number of unpacked frames.
// Always start with the existing vfst.method and bci.
// Do not call vfst.next to advance over the last returned value.
// In other words, do not leave any stale data in the vfst.
//
// Parameters:
// mode Restrict which frames to be decoded.
// BaseFrameStream stream of frames
// max_nframes Maximum number of frames to be filled.
// start_index Start index to the user-supplied buffers.
// frames_array Buffer to store Class or 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.
// end_index End index to the user-supplied buffers with unpacked frames.
//
// Returns the number of frames whose information was transferred into the buffers.
//
int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream,
int max_nframes, int start_index,
objArrayHandle frames_array,
int& end_index, TRAPS) {
log_debug(stackwalk)("fill_in_frames limit=%d start=%d frames length=%d",
max_nframes, start_index, frames_array->length());
assert(max_nframes > 0, "invalid max_nframes");
assert(start_index + max_nframes <= frames_array->length(), "oob");
int frames_decoded = 0;
for (; !stream.at_end(); stream.next()) {
Method* method = stream.method();
if (method == NULL) continue;
// skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
// not set) and when StackWalker::getCallerClass is called
if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
if (method->is_hidden()) {
if (log_is_enabled(Debug, stackwalk)) {
ResourceMark rm(THREAD);
outputStream* st = Log(stackwalk)::debug_stream();
st->print(" hidden method: ");
method->print_short_name(st);
st->cr();
}
continue;
}
}
int index = end_index++;
if (log_is_enabled(Debug, stackwalk)) {
ResourceMark rm(THREAD);
outputStream* st = Log(stackwalk)::debug_stream();
st->print(" %d: frame method: ", index);
method->print_short_name(st);
st->print_cr(" bci=%d", stream.bci());
}
if (!need_method_info(mode) && get_caller_class(mode) &&
index == start_index && method->caller_sensitive()) {
ResourceMark rm(THREAD);
THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(),
err_msg("StackWalker::getCallerClass called from @CallerSensitive %s method",
method->name_and_sig_as_C_string()));
}
// fill in StackFrameInfo and initialize MemberName
stream.fill_frame(index, frames_array, method, CHECK_0);
if (++frames_decoded >= max_nframes) break;
}
return frames_decoded;
}
// Unpacks one or more frames into user-supplied buffers.
// Updates the end index, and returns the number of unpacked frames.
// Always start with the existing vfst.method and bci.
// Do not call vfst.next to advance over the last returned value.
// In other words, do not leave any stale data in the vfst.
//
// Parameters:
// mode Restrict which frames to be decoded.
// JavaFrameStream stream of javaVFrames
// max_nframes Maximum number of frames to be filled.
// start_index Start index to the user-supplied buffers.
// frames_array Buffer to store Class or 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.
// end_index End index to the user-supplied buffers with unpacked frames.
//
// Returns the number of frames whose information was transferred into the buffers.
//
int StackWalk::fill_in_frames(jlong mode, JavaFrameStream& stream,
int max_nframes, int start_index,
objArrayHandle frames_array,
int& end_index, TRAPS) {
if (TraceStackWalk) {
tty->print_cr("fill_in_frames limit=%d start=%d frames length=%d",
max_nframes, start_index, frames_array->length());
}
assert(max_nframes > 0, "invalid max_nframes");
assert(start_index + max_nframes <= frames_array->length(), "oob");
int frames_decoded = 0;
for (; !stream.at_end(); stream.next()) {
Method* method = stream.method();
int bci = stream.bci();
if (method == NULL) continue;
if (!ShowHiddenFrames && StackWalk::skip_hidden_frames(mode)) {
if (method->is_hidden()) {
if (TraceStackWalk) {
tty->print(" hidden method: "); method->print_short_name();
tty->print("\n");
}
continue;
}
}
int index = end_index++;
if (TraceStackWalk) {
tty->print(" %d: frame method: ", index); method->print_short_name();
tty->print_cr(" bci=%d", bci);
}
// fill in StackFrameInfo and initialize MemberName
if (live_frame_info(mode)) {
assert (use_frames_array(mode), "Bad mode for get live frame");
Handle stackFrame(frames_array->obj_at(index));
fill_live_stackframe(stackFrame, method, bci, stream.java_frame(), CHECK_0);
} else if (need_method_info(mode)) {
assert (use_frames_array(mode), "Bad mode for get stack frame");
Handle stackFrame(frames_array->obj_at(index));
fill_stackframe(stackFrame, method, bci);
} else {
assert (use_frames_array(mode) == false, "Bad mode for get caller class");
frames_array->obj_at_put(index, method->method_holder()->java_mirror());
}
if (++frames_decoded >= max_nframes) break;
}
return frames_decoded;
}
