/* * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ // vframes are virtual stack frames representing source level activations. // A single frame may hold several source level activations in the case of // optimized code. The debugging stored with the optimized code enables // us to unfold a frame as a stack of vframes. // A cVFrame represents an activation of a non-java method. // The vframe inheritance hierarchy: // - vframe // - javaVFrame // - interpretedVFrame // - compiledVFrame ; (used for both compiled Java methods and native stubs) // - externalVFrame // - entryVFrame ; special frame created when calling Java from C // - BasicLock class vframe: public ResourceObj { protected: frame _fr; // Raw frame behind the virtual frame. RegisterMap _reg_map; // Register map for the raw frame (used to handle callee-saved registers). JavaThread* _thread; // The thread owning the raw frame. vframe(const frame* fr, const RegisterMap* reg_map, JavaThread* thread); vframe(const frame* fr, JavaThread* thread); public: // Factory method for creating vframes static vframe* new_vframe(const frame* f, const RegisterMap *reg_map, JavaThread* thread); // Accessors frame fr() const { return _fr; } CodeBlob* cb() const { return _fr.cb(); } nmethod* nm() const { assert( cb() != NULL && cb()->is_nmethod(), "usage"); return (nmethod*) cb(); } // ???? Does this need to be a copy? frame* frame_pointer() { return &_fr; } const RegisterMap* register_map() const { return &_reg_map; } JavaThread* thread() const { return _thread; } // Returns the sender vframe virtual vframe* sender() const; // Returns the next javaVFrame on the stack (skipping all other kinds of frame) javaVFrame *java_sender() const; // Answers if the this is the top vframe in the frame, i.e., if the sender vframe // is in the caller frame virtual bool is_top() const { return true; } // Returns top vframe within same frame (see is_top()) virtual vframe* top() const; // Type testing operations virtual bool is_entry_frame() const { return false; } virtual bool is_java_frame() const { return false; } virtual bool is_interpreted_frame() const { return false; } virtual bool is_compiled_frame() const { return false; } #ifndef PRODUCT // printing operations virtual void print_value() const; virtual void print(); #endif }; class javaVFrame: public vframe { public: // JVM state virtual methodOop method() const = 0; virtual int bci() const = 0; virtual StackValueCollection* locals() const = 0; virtual StackValueCollection* expressions() const = 0; // the order returned by monitors() is from oldest -> youngest#4418568 virtual GrowableArray* monitors() const = 0; // Debugging support via JVMTI. // NOTE that this is not guaranteed to give correct results for compiled vframes. // Deoptimize first if necessary. virtual void set_locals(StackValueCollection* values) const = 0; // Test operation bool is_java_frame() const { return true; } protected: javaVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {} javaVFrame(const frame* fr, JavaThread* thread) : vframe(fr, thread) {} public: // casting static javaVFrame* cast(vframe* vf) { assert(vf == NULL || vf->is_java_frame(), "must be java frame"); return (javaVFrame*) vf; } // Return an array of monitors locked by this frame in the youngest to oldest order GrowableArray* locked_monitors(); // printing used during stack dumps void print_lock_info_on(outputStream* st, int frame_count); void print_lock_info(int frame_count) { print_lock_info_on(tty, frame_count); } #ifndef PRODUCT public: // printing operations void print(); void print_value() const; void print_activation(int index) const; // verify operations virtual void verify() const; // Structural compare bool structural_compare(javaVFrame* other); #endif friend class vframe; }; class interpretedVFrame: public javaVFrame { public: // JVM state methodOop method() const; int bci() const; StackValueCollection* locals() const; StackValueCollection* expressions() const; GrowableArray* monitors() const; void set_locals(StackValueCollection* values) const; // Test operation bool is_interpreted_frame() const { return true; } protected: interpretedVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : javaVFrame(fr, reg_map, thread) {}; public: // Accessors for Byte Code Pointer u_char* bcp() const; void set_bcp(u_char* bcp); // casting static interpretedVFrame* cast(vframe* vf) { assert(vf == NULL || vf->is_interpreted_frame(), "must be interpreted frame"); return (interpretedVFrame*) vf; } private: static const int bcp_offset; intptr_t* locals_addr_at(int offset) const; // returns where the parameters starts relative to the frame pointer int start_of_parameters() const; #ifndef PRODUCT public: // verify operations void verify() const; #endif friend class vframe; }; class externalVFrame: public vframe { protected: externalVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {} #ifndef PRODUCT public: // printing operations void print_value() const; void print(); #endif friend class vframe; }; class entryVFrame: public externalVFrame { public: bool is_entry_frame() const { return true; } protected: entryVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread); public: // casting static entryVFrame* cast(vframe* vf) { assert(vf == NULL || vf->is_entry_frame(), "must be entry frame"); return (entryVFrame*) vf; } #ifndef PRODUCT public: // printing void print_value() const; void print(); #endif friend class vframe; }; // A MonitorInfo is a ResourceObject that describes a the pair: // 1) the owner of the monitor // 2) the monitor lock class MonitorInfo : public ResourceObj { private: oop _owner; // the object owning the monitor BasicLock* _lock; oop _owner_klass; // klass if owner was scalar replaced bool _eliminated; bool _owner_is_scalar_replaced; public: // Constructor MonitorInfo(oop owner, BasicLock* lock, bool eliminated, bool owner_is_scalar_replaced) { if (!owner_is_scalar_replaced) { _owner = owner; _owner_klass = NULL; } else { assert(eliminated, "monitor should be eliminated for scalar replaced object"); _owner = NULL; _owner_klass = owner; } _lock = lock; _eliminated = eliminated; _owner_is_scalar_replaced = owner_is_scalar_replaced; } // Accessors oop owner() const { assert(!_owner_is_scalar_replaced, "should not be called for scalar replaced object"); return _owner; } klassOop owner_klass() const { assert(_owner_is_scalar_replaced, "should not be called for not scalar replaced object"); return (klassOop)_owner_klass; } BasicLock* lock() const { return _lock; } bool eliminated() const { return _eliminated; } bool owner_is_scalar_replaced() const { return _owner_is_scalar_replaced; } }; class vframeStreamCommon : StackObj { protected: // common frame _frame; JavaThread* _thread; RegisterMap _reg_map; enum { interpreted_mode, compiled_mode, at_end_mode } _mode; int _sender_decode_offset; // Cached information methodOop _method; int _bci; // Should VM activations be ignored or not bool _stop_at_java_call_stub; bool fill_in_compiled_inlined_sender(); void fill_from_compiled_frame(int decode_offset); void fill_from_compiled_native_frame(); void found_bad_method_frame(); void fill_from_interpreter_frame(); bool fill_from_frame(); // Helper routine for security_get_caller_frame void skip_prefixed_method_and_wrappers(); public: // Constructor vframeStreamCommon(JavaThread* thread) : _reg_map(thread, false) { _thread = thread; } // Accessors methodOop method() const { return _method; } int bci() const { return _bci; } intptr_t* frame_id() const { return _frame.id(); } address frame_pc() const { return _frame.pc(); } CodeBlob* cb() const { return _frame.cb(); } nmethod* nm() const { assert( cb() != NULL && cb()->is_nmethod(), "usage"); return (nmethod*) cb(); } // Frame type bool is_interpreted_frame() const { return _frame.is_interpreted_frame(); } bool is_entry_frame() const { return _frame.is_entry_frame(); } // Iteration void next() { // handle frames with inlining if (_mode == compiled_mode && fill_in_compiled_inlined_sender()) return; // handle general case do { _frame = _frame.sender(&_reg_map); } while (!fill_from_frame()); } bool at_end() const { return _mode == at_end_mode; } // Implements security traversal. Skips depth no. of frame including // special security frames and prefixed native methods void security_get_caller_frame(int depth); // Helper routine for JVM_LatestUserDefinedLoader -- needed for 1.4 // reflection implementation void skip_reflection_related_frames(); }; class vframeStream : public vframeStreamCommon { public: // Constructors vframeStream(JavaThread* thread, bool stop_at_java_call_stub = false) : vframeStreamCommon(thread) { _stop_at_java_call_stub = stop_at_java_call_stub; if (!thread->has_last_Java_frame()) { _mode = at_end_mode; return; } _frame = _thread->last_frame(); while (!fill_from_frame()) { _frame = _frame.sender(&_reg_map); } } // top_frame may not be at safepoint, start with sender vframeStream(JavaThread* thread, frame top_frame, bool stop_at_java_call_stub = false); }; inline bool vframeStreamCommon::fill_in_compiled_inlined_sender() { if (_sender_decode_offset == DebugInformationRecorder::serialized_null) { return false; } fill_from_compiled_frame(_sender_decode_offset); return true; } inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) { _mode = compiled_mode; // Range check to detect ridiculous offsets. if (decode_offset == DebugInformationRecorder::serialized_null || decode_offset < 0 || decode_offset >= nm()->scopes_data_size()) { // 6379830 AsyncGetCallTrace sometimes feeds us wild frames. // If we attempt to read nmethod::scopes_data at serialized_null (== 0), // or if we read some at other crazy offset, // we will decode garbage and make wild references into the heap, // leading to crashes in product mode. // (This isn't airtight, of course, since there are internal // offsets which are also crazy.) #ifdef ASSERT if (WizardMode) { tty->print_cr("Error in fill_from_frame: pc_desc for " INTPTR_FORMAT " not found or invalid at %d", _frame.pc(), decode_offset); nm()->print(); nm()->method()->print_codes(); nm()->print_code(); nm()->print_pcs(); } #endif // Provide a cheap fallback in product mode. (See comment above.) found_bad_method_frame(); fill_from_compiled_native_frame(); return; } // Decode first part of scopeDesc DebugInfoReadStream buffer(nm(), decode_offset); _sender_decode_offset = buffer.read_int(); _method = methodOop(buffer.read_oop()); // Deoptimization needs reexecute bit to determine whether to reexecute the bytecode // only at the time when it "unpack_frames", and the reexecute bit info could always // be obtained from the scopeDesc in the compiledVFrame. As a result, we don't keep // the reexecute bit here. bool dummy_reexecute; _bci = buffer.read_bci_and_reexecute(dummy_reexecute); assert(_method->is_method(), "checking type of decoded method"); } // The native frames are handled specially. We do not rely on ScopeDesc info // since the pc might not be exact due to the _last_native_pc trick. inline void vframeStreamCommon::fill_from_compiled_native_frame() { _mode = compiled_mode; _sender_decode_offset = DebugInformationRecorder::serialized_null; _method = nm()->method(); _bci = 0; } inline bool vframeStreamCommon::fill_from_frame() { // Interpreted frame if (_frame.is_interpreted_frame()) { fill_from_interpreter_frame(); return true; } // Compiled frame if (cb() != NULL && cb()->is_nmethod()) { if (nm()->is_native_method()) { // Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick. fill_from_compiled_native_frame(); } else { PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc()); int decode_offset; if (pc_desc == NULL) { // Should not happen, but let fill_from_compiled_frame handle it. // If we are trying to walk the stack of a thread that is not // at a safepoint (like AsyncGetCallTrace would do) then this is an // acceptable result. [ This is assuming that safe_for_sender // is so bullet proof that we can trust the frames it produced. ] // // So if we see that the thread is not safepoint safe // then simply produce the method and a bci of zero // and skip the possibility of decoding any inlining that // may be present. That is far better than simply stopping (or // asserting. If however the thread is safepoint safe this // is the sign of a compiler bug and we'll let // fill_from_compiled_frame handle it. JavaThreadState state = _thread->thread_state(); // in_Java should be good enough to test safepoint safety // if state were say in_Java_trans then we'd expect that // the pc would have already been slightly adjusted to // one that would produce a pcDesc since the trans state // would be one that might in fact anticipate a safepoint if (state == _thread_in_Java ) { // This will get a method a zero bci and no inlining. // Might be nice to have a unique bci to signify this // particular case but for now zero will do. fill_from_compiled_native_frame(); // There is something to be said for setting the mode to // at_end_mode to prevent trying to walk further up the // stack. There is evidence that if we walk any further // that we could produce a bad stack chain. However until // we see evidence that allowing this causes us to find // frames bad enough to cause segv's or assertion failures // we don't do it as while we may get a bad call chain the // probability is much higher (several magnitudes) that we // get good data. return true; } decode_offset = DebugInformationRecorder::serialized_null; } else { decode_offset = pc_desc->scope_decode_offset(); } fill_from_compiled_frame(decode_offset); } return true; } // End of stack? if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) { _mode = at_end_mode; return true; } return false; } inline void vframeStreamCommon::fill_from_interpreter_frame() { methodOop method = _frame.interpreter_frame_method(); intptr_t bcx = _frame.interpreter_frame_bcx(); int bci = method->validate_bci_from_bcx(bcx); // 6379830 AsyncGetCallTrace sometimes feeds us wild frames. if (bci < 0) { found_bad_method_frame(); bci = 0; // pretend it's on the point of entering } _mode = interpreted_mode; _method = method; _bci = bci; }