// 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.
// vfst vFrameStream.
// max_nframes Maximum number of frames to be filled.
// start_index Start index to the user-supplied buffers.
// classes_array Buffer to store classes in, starting at start_index.
// frames_array Buffer to store StackFrame in, starting at start_index.
// NULL if not used.
// 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, vframeStream& vfst,
int max_nframes, int start_index,
objArrayHandle classes_array,
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, classes_array->length());
}
assert(max_nframes > 0, "invalid max_nframes");
assert(start_index + max_nframes <= classes_array->length(), "oob");
int frames_decoded = 0;
for (; !vfst.at_end(); vfst.next()) {
Method* method = vfst.method();
int bci = vfst.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);
}
classes_array->obj_at_put(index, method->method_holder()->java_mirror());
// fill in StackFrameInfo and initialize MemberName
if (live_frame_info(mode)) {
Handle stackFrame(frames_array->obj_at(index));
fill_live_stackframe(stackFrame, method, bci, vfst.java_frame(), CHECK_0);
} else if (need_method_info(mode)) {
Handle stackFrame(frames_array->obj_at(index));
fill_stackframe(stackFrame, method, bci);
}
if (++frames_decoded >= max_nframes) break;
}
return frames_decoded;
}
int bci() { return _vfst.bci(); }
bool at_end() { return _vfst.at_end(); }
Method* method() { return _vfst.method(); }
void next() { _vfst.next();}