# HG changeset patch # User bchristi # Date 1474391095 25200 # Node ID 74b314ad1e9a3924f6837a55fdf78850f369b583 # Parent 5a7c83da4a2dd93fd93baf3ca2ad7ec59d1c51b8 8165372: StackWalker performance regression following JDK-8147039 Summary: Stack walking can use javaVFrame or vframeStream Reviewed-by: coleenp, mchung diff -r 5a7c83da4a2d -r 74b314ad1e9a hotspot/src/share/vm/prims/jvm.cpp --- a/hotspot/src/share/vm/prims/jvm.cpp Tue Sep 20 11:41:43 2016 +0200 +++ b/hotspot/src/share/vm/prims/jvm.cpp Tue Sep 20 10:04:55 2016 -0700 @@ -562,8 +562,8 @@ } Handle stackStream_h(THREAD, JNIHandles::resolve_non_null(stackStream)); - return StackWalk::moreFrames(stackStream_h, mode, anchor, frame_count, - start_index, frames_array_h, THREAD); + return StackWalk::fetchNextBatch(stackStream_h, mode, anchor, frame_count, + start_index, frames_array_h, THREAD); JVM_END JVM_ENTRY(void, JVM_ToStackTraceElement(JNIEnv *env, jobject frame, jobject stack)) diff -r 5a7c83da4a2d -r 74b314ad1e9a hotspot/src/share/vm/prims/stackwalk.cpp --- a/hotspot/src/share/vm/prims/stackwalk.cpp Tue Sep 20 11:41:43 2016 +0200 +++ b/hotspot/src/share/vm/prims/stackwalk.cpp Tue Sep 20 10:04:55 2016 -0700 @@ -37,42 +37,47 @@ #include "utilities/globalDefinitions.hpp" // setup and cleanup actions -void JavaFrameStream::setup_magic_on_entry(objArrayHandle frames_array) { +void BaseFrameStream::setup_magic_on_entry(objArrayHandle frames_array) { frames_array->obj_at_put(magic_pos, _thread->threadObj()); _anchor = address_value(); assert(check_magic(frames_array), "invalid magic"); } -bool JavaFrameStream::check_magic(objArrayHandle frames_array) { +bool BaseFrameStream::check_magic(objArrayHandle frames_array) { oop m1 = frames_array->obj_at(magic_pos); jlong m2 = _anchor; if (m1 == _thread->threadObj() && m2 == address_value()) return true; return false; } -bool JavaFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) { +bool BaseFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) { bool ok = check_magic(frames_array); frames_array->obj_at_put(magic_pos, NULL); _anchor = 0L; return ok; } -// Returns JavaFrameStream for the current stack being traversed. +JavaFrameStream::JavaFrameStream(JavaThread* thread, int mode) + : BaseFrameStream(thread), _vfst(thread) { + _need_method_info = StackWalk::need_method_info(mode); +} + +// Returns the BaseFrameStream for the current stack being traversed. // // Parameters: // thread Current Java thread. // magic Magic value used for each stack walking // frames_array User-supplied buffers. The 0th element is reserved -// to this JavaFrameStream to use +// for this BaseFrameStream to use // -JavaFrameStream* JavaFrameStream::from_current(JavaThread* thread, jlong magic, +BaseFrameStream* BaseFrameStream::from_current(JavaThread* thread, jlong magic, objArrayHandle frames_array) { assert(thread != NULL && thread->is_Java_thread(), ""); oop m1 = frames_array->obj_at(magic_pos); if (m1 != thread->threadObj()) return NULL; if (magic == 0L) return NULL; - JavaFrameStream* stream = (JavaFrameStream*) (intptr_t) magic; + BaseFrameStream* stream = (BaseFrameStream*) (intptr_t) magic; if (!stream->is_valid_in(thread, frames_array)) return NULL; return stream; } @@ -85,7 +90,7 @@ // // Parameters: // mode Restrict which frames to be decoded. -// JavaFrameStream stream of javaVFrames +// 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. @@ -96,7 +101,7 @@ // // Returns the number of frames whose information was transferred into the buffers. // -int StackWalk::fill_in_frames(jlong mode, JavaFrameStream& stream, +int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream, int max_nframes, int start_index, objArrayHandle frames_array, int& end_index, TRAPS) { @@ -110,7 +115,6 @@ int frames_decoded = 0; for (; !stream.at_end(); stream.next()) { Method* method = stream.method(); - int bci = stream.bci(); if (method == NULL) continue; @@ -129,35 +133,42 @@ int index = end_index++; if (TraceStackWalk) { tty->print(" %d: frame method: ", index); method->print_short_name(); - tty->print_cr(" bci=%d", bci); + tty->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 - 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 filling in Class object"); - if (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())); - } - - frames_array->obj_at_put(index, method->method_holder()->java_mirror()); - } + stream.fill_frame(index, frames_array, method, CHECK_0); if (++frames_decoded >= max_nframes) break; } return frames_decoded; } -static oop create_primitive_value_instance(StackValueCollection* values, int i, TRAPS) { +// Fill in the LiveStackFrameInfo at the given index in frames_array +void LiveFrameStream::fill_frame(int index, objArrayHandle frames_array, + const methodHandle& method, TRAPS) { + Handle stackFrame(THREAD, frames_array->obj_at(index)); + fill_live_stackframe(stackFrame, method, CHECK); +} + +// Fill in the StackFrameInfo at the given index in frames_array +void JavaFrameStream::fill_frame(int index, objArrayHandle frames_array, + const methodHandle& method, TRAPS) { + if (_need_method_info) { + Handle stackFrame(THREAD, frames_array->obj_at(index)); + fill_stackframe(stackFrame, method); + } else { + frames_array->obj_at_put(index, method->method_holder()->java_mirror()); + } +} + +oop LiveFrameStream::create_primitive_value_instance(StackValueCollection* values, int i, TRAPS) { Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL); instanceKlassHandle ik (THREAD, k); @@ -228,7 +239,7 @@ return (instanceOop) result.get_jobject(); } -static objArrayHandle values_to_object_array(StackValueCollection* values, TRAPS) { +objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPS) { objArrayHandle empty; int length = values->size(); objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), @@ -243,7 +254,7 @@ return array_h; } -static objArrayHandle monitors_to_object_array(GrowableArray* monitors, TRAPS) { +objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray* monitors, TRAPS) { int length = monitors->length(); objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), length, CHECK_(objArrayHandle())); @@ -256,19 +267,19 @@ } // Fill StackFrameInfo with declaringClass and bci and initialize memberName -void StackWalk::fill_stackframe(Handle stackFrame, const methodHandle& method, int bci) { +void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method) { java_lang_StackFrameInfo::set_declaringClass(stackFrame(), method->method_holder()->java_mirror()); - java_lang_StackFrameInfo::set_method_and_bci(stackFrame(), method, bci); + java_lang_StackFrameInfo::set_method_and_bci(stackFrame(), method, bci()); } // Fill LiveStackFrameInfo with locals, monitors, and expressions -void StackWalk::fill_live_stackframe(Handle stackFrame, const methodHandle& method, - int bci, javaVFrame* jvf, TRAPS) { - fill_stackframe(stackFrame, method, bci); - if (jvf != NULL) { - StackValueCollection* locals = jvf->locals(); - StackValueCollection* expressions = jvf->expressions(); - GrowableArray* monitors = jvf->monitors(); +void LiveFrameStream::fill_live_stackframe(Handle stackFrame, + const methodHandle& method, TRAPS) { + fill_stackframe(stackFrame, method); + if (_jvf != NULL) { + StackValueCollection* locals = _jvf->locals(); + StackValueCollection* expressions = _jvf->expressions(); + GrowableArray* monitors = _jvf->monitors(); if (!locals->is_empty()) { objArrayHandle locals_h = values_to_object_array(locals, CHECK); @@ -315,15 +326,26 @@ THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL); } - Klass* stackWalker_klass = SystemDictionary::StackWalker_klass(); - Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass(); + // 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, CHECK_NULL); + } else { + JavaFrameStream stream(jt, mode); + return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count, start_index, frames_array, CHECK_NULL); + } +} +oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream, + jlong mode, int skip_frames, int frame_count, + int start_index, objArrayHandle frames_array, TRAPS) { methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method()); - // Setup traversal onto my stack. - RegisterMap regMap(jt, true); - JavaFrameStream stream(jt, ®Map); { + Klass* stackWalker_klass = SystemDictionary::StackWalker_klass(); + Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass(); while (!stream.at_end()) { InstanceKlass* ik = stream.method()->method_holder(); if (ik != stackWalker_klass && @@ -341,10 +363,7 @@ // 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())); + tty->print(" skip "); stream.method()->print_short_name(); tty->cr(); } } } @@ -402,13 +421,13 @@ // // Returns the end index of frame filled in the buffer. // -jint StackWalk::moreFrames(Handle stackStream, jlong mode, jlong magic, - int frame_count, int start_index, - objArrayHandle frames_array, - TRAPS) +jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic, + int frame_count, int start_index, + objArrayHandle frames_array, + TRAPS) { JavaThread* jt = (JavaThread*)THREAD; - JavaFrameStream* existing_stream = JavaFrameStream::from_current(jt, magic, frames_array); + BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array); if (existing_stream == NULL) { THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L); } @@ -418,7 +437,7 @@ } if (TraceStackWalk) { - tty->print_cr("StackWalk::moreFrames frame_count %d existing_stream " PTR_FORMAT " start %d frames %d", + tty->print_cr("StackWalk::fetchNextBatch frame_count %d existing_stream " PTR_FORMAT " start %d frames %d", frame_count, p2i(existing_stream), start_index, frames_array->length()); } int end_index = start_index; @@ -429,7 +448,7 @@ int count = frame_count + start_index; assert (frames_array->length() >= count, "not enough space in buffers"); - JavaFrameStream& stream = (*existing_stream); + BaseFrameStream& stream = (*existing_stream); if (!stream.at_end()) { stream.next(); // advance past the last frame decoded in previous batch if (!stream.at_end()) { diff -r 5a7c83da4a2d -r 74b314ad1e9a hotspot/src/share/vm/prims/stackwalk.hpp --- a/hotspot/src/share/vm/prims/stackwalk.hpp Tue Sep 20 11:41:43 2016 +0200 +++ b/hotspot/src/share/vm/prims/stackwalk.hpp Tue Sep 20 10:04:55 2016 -0700 @@ -29,31 +29,34 @@ #include "oops/oop.hpp" #include "runtime/vframe.hpp" -// -// JavaFrameStream is used by StackWalker to iterate through Java stack frames -// on the given JavaThread. -// -class JavaFrameStream : public StackObj { +// BaseFrameStream is an abstract base class for encapsulating the VM-side +// implementation of the StackWalker API. There are two concrete subclasses: +// - JavaFrameStream: +// -based on vframeStream; used in most instances +// - LiveFrameStream: +// -based on javaVFrame; used for retrieving locals/monitors/operands for +// LiveStackFrame +class BaseFrameStream : public StackObj { private: enum { magic_pos = 0 }; JavaThread* _thread; - javaVFrame* _jvf; jlong _anchor; +protected: + void fill_stackframe(Handle stackFrame, const methodHandle& method); public: - JavaFrameStream(JavaThread* thread, RegisterMap* rm) - : _thread(thread), _anchor(0L) { - _jvf = _thread->last_java_vframe(rm); - } + BaseFrameStream(JavaThread* thread) : _thread(thread), _anchor(0L) {} + + virtual void next()=0; + virtual bool at_end()=0; - javaVFrame* java_frame() { return _jvf; } - void next() { _jvf = _jvf->java_sender(); } - bool at_end() { return _jvf == NULL; } + virtual Method* method()=0; + virtual int bci()=0; - Method* method() { return _jvf->method(); } - int bci() { return _jvf->bci(); } + virtual void fill_frame(int index, objArrayHandle frames_array, + const methodHandle& method, TRAPS)=0; void setup_magic_on_entry(objArrayHandle frames_array); bool check_magic(objArrayHandle frames_array); @@ -67,35 +70,72 @@ return (jlong) castable_address(this); } - static JavaFrameStream* from_current(JavaThread* thread, jlong magic, objArrayHandle frames_array); + static BaseFrameStream* from_current(JavaThread* thread, jlong magic, objArrayHandle frames_array); +}; + +class JavaFrameStream : public BaseFrameStream { +private: + vframeStream _vfst; + bool _need_method_info; +public: + JavaFrameStream(JavaThread* thread, int mode); + + void next() { _vfst.next();} + bool at_end() { return _vfst.at_end(); } + + Method* method() { return _vfst.method(); } + int bci() { return _vfst.bci(); } + + void fill_frame(int index, objArrayHandle frames_array, + const methodHandle& method, TRAPS); +}; + +class LiveFrameStream : public BaseFrameStream { +private: + javaVFrame* _jvf; + + void fill_live_stackframe(Handle stackFrame, const methodHandle& method, TRAPS); + static oop create_primitive_value_instance(StackValueCollection* values, + int i, TRAPS); + static objArrayHandle monitors_to_object_array(GrowableArray* monitors, + TRAPS); + static objArrayHandle values_to_object_array(StackValueCollection* values, TRAPS); +public: + LiveFrameStream(JavaThread* thread, RegisterMap* rm) : BaseFrameStream(thread) { + _jvf = thread->last_java_vframe(rm); + } + + void next() { _jvf = _jvf->java_sender(); } + bool at_end() { return _jvf == NULL; } + + Method* method() { return _jvf->method(); } + int bci() { return _jvf->bci(); } + + void fill_frame(int index, objArrayHandle frames_array, + const methodHandle& method, TRAPS); }; class StackWalk : public AllStatic { private: - static int fill_in_frames(jlong mode, JavaFrameStream& stream, + static int fill_in_frames(jlong mode, BaseFrameStream& stream, int max_nframes, int start_index, objArrayHandle frames_array, int& end_index, TRAPS); - static void fill_stackframe(Handle stackFrame, const methodHandle& method, int bci); - - static void fill_live_stackframe(Handle stackFrame, const methodHandle& method, int bci, - javaVFrame* jvf, TRAPS); - static inline bool get_caller_class(int mode) { return (mode & JVM_STACKWALK_GET_CALLER_CLASS) != 0; } static inline bool skip_hidden_frames(int mode) { return (mode & JVM_STACKWALK_SHOW_HIDDEN_FRAMES) == 0; } - static inline bool need_method_info(int mode) { - return (mode & JVM_STACKWALK_FILL_CLASS_REFS_ONLY) == 0; - } static inline bool live_frame_info(int mode) { return (mode & JVM_STACKWALK_FILL_LIVE_STACK_FRAMES) != 0; } public: + static inline bool need_method_info(int mode) { + return (mode & JVM_STACKWALK_FILL_CLASS_REFS_ONLY) == 0; + } static inline bool use_frames_array(int mode) { return (mode & JVM_STACKWALK_FILL_CLASS_REFS_ONLY) == 0; } @@ -104,9 +144,12 @@ objArrayHandle frames_array, TRAPS); - static jint moreFrames(Handle stackStream, jlong mode, jlong magic, - int frame_count, int start_index, - objArrayHandle frames_array, - TRAPS); + static oop fetchFirstBatch(BaseFrameStream& stream, Handle stackStream, + jlong mode, int skip_frames, int frame_count, + int start_index, objArrayHandle frames_array, TRAPS); + + static jint fetchNextBatch(Handle stackStream, jlong mode, jlong magic, + int frame_count, int start_index, + objArrayHandle frames_array, TRAPS); }; #endif // SHARE_VM_PRIMS_STACKWALK_HPP