/* * Copyright (c) 1997, 2011, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_CODE_NMETHOD_HPP #define SHARE_VM_CODE_NMETHOD_HPP #include "code/codeBlob.hpp" #include "code/pcDesc.hpp" // This class is used internally by nmethods, to cache // exception/pc/handler information. class ExceptionCache : public CHeapObj { friend class VMStructs; private: enum { cache_size = 16 }; klassOop _exception_type; address _pc[cache_size]; address _handler[cache_size]; int _count; ExceptionCache* _next; address pc_at(int index) { assert(index >= 0 && index < count(),""); return _pc[index]; } void set_pc_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _pc[index] = a; } address handler_at(int index) { assert(index >= 0 && index < count(),""); return _handler[index]; } void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; } int count() { return _count; } void increment_count() { _count++; } public: ExceptionCache(Handle exception, address pc, address handler); klassOop exception_type() { return _exception_type; } klassOop* exception_type_addr() { return &_exception_type; } ExceptionCache* next() { return _next; } void set_next(ExceptionCache *ec) { _next = ec; } address match(Handle exception, address pc); bool match_exception_with_space(Handle exception) ; address test_address(address addr); bool add_address_and_handler(address addr, address handler) ; }; // cache pc descs found in earlier inquiries class PcDescCache VALUE_OBJ_CLASS_SPEC { friend class VMStructs; private: enum { cache_size = 4 }; PcDesc* _pc_descs[cache_size]; // last cache_size pc_descs found public: PcDescCache() { debug_only(_pc_descs[0] = NULL); } void reset_to(PcDesc* initial_pc_desc); PcDesc* find_pc_desc(int pc_offset, bool approximate); void add_pc_desc(PcDesc* pc_desc); PcDesc* last_pc_desc() { return _pc_descs[0]; } }; // nmethods (native methods) are the compiled code versions of Java methods. // // An nmethod contains: // - header (the nmethod structure) // [Relocation] // - relocation information // - constant part (doubles, longs and floats used in nmethod) // - oop table // [Code] // - code body // - exception handler // - stub code // [Debugging information] // - oop array // - data array // - pcs // [Exception handler table] // - handler entry point array // [Implicit Null Pointer exception table] // - implicit null table array class Dependencies; class ExceptionHandlerTable; class ImplicitExceptionTable; class AbstractCompiler; class xmlStream; class nmethod : public CodeBlob { friend class VMStructs; friend class NMethodSweeper; friend class CodeCache; // non-perm oops private: // Shared fields for all nmethod's methodOop _method; int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method jmethodID _jmethod_id; // Cache of method()->jmethod_id() // To support simple linked-list chaining of nmethods: nmethod* _osr_link; // from instanceKlass::osr_nmethods_head nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods nmethod* _saved_nmethod_link; // from CodeCache::speculatively_disconnect static nmethod* volatile _oops_do_mark_nmethods; nmethod* volatile _oops_do_mark_link; AbstractCompiler* _compiler; // The compiler which compiled this nmethod // offsets for entry points address _entry_point; // entry point with class check address _verified_entry_point; // entry point without class check address _osr_entry_point; // entry point for on stack replacement // Offsets for different nmethod parts int _exception_offset; // All deoptee's will resume execution at this location described by // this offset. int _deoptimize_offset; // All deoptee's at a MethodHandle call site will resume execution // at this location described by this offset. int _deoptimize_mh_offset; // Offset of the unwind handler if it exists int _unwind_handler_offset; #ifdef HAVE_DTRACE_H int _trap_offset; #endif // def HAVE_DTRACE_H int _consts_offset; int _stub_offset; int _oops_offset; // offset to where embedded oop table begins (inside data) int _scopes_data_offset; int _scopes_pcs_offset; int _dependencies_offset; int _handler_table_offset; int _nul_chk_table_offset; int _nmethod_end_offset; // location in frame (offset for sp) that deopt can store the original // pc during a deopt. int _orig_pc_offset; int _compile_id; // which compilation made this nmethod int _comp_level; // compilation level // protected by CodeCache_lock bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock) bool _speculatively_disconnected; // Marked for potential unload bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper) bool _marked_for_deoptimization; // Used for stack deoptimization // used by jvmti to track if an unload event has been posted for this nmethod. bool _unload_reported; // set during construction unsigned int _has_unsafe_access:1; // May fault due to unsafe access. unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes? // Protected by Patching_lock unsigned char _state; // {alive, not_entrant, zombie, unloaded} #ifdef ASSERT bool _oops_are_stale; // indicates that it's no longer safe to access oops section #endif enum { alive = 0, not_entrant = 1, // uncommon trap has happened but activations may still exist zombie = 2, unloaded = 3 }; jbyte _scavenge_root_state; NOT_PRODUCT(bool _has_debug_info; ) // Nmethod Flushing lock. If non-zero, then the nmethod is not removed // and is not made into a zombie. However, once the nmethod is made into // a zombie, it will be locked one final time if CompiledMethodUnload // event processing needs to be done. jint _lock_count; // not_entrant method removal. Each mark_sweep pass will update // this mark to current sweep invocation count if it is seen on the // stack. An not_entrant method can be removed when there is no // more activations, i.e., when the _stack_traversal_mark is less than // current sweep traversal index. long _stack_traversal_mark; ExceptionCache *_exception_cache; PcDescCache _pc_desc_cache; // These are used for compiled synchronized native methods to // locate the owner and stack slot for the BasicLock so that we can // properly revoke the bias of the owner if necessary. They are // needed because there is no debug information for compiled native // wrappers and the oop maps are insufficient to allow // frame::retrieve_receiver() to work. Currently they are expected // to be byte offsets from the Java stack pointer for maximum code // sharing between platforms. Note that currently biased locking // will never cause Class instances to be biased but this code // handles the static synchronized case as well. // JVMTI's GetLocalInstance() also uses these offsets to find the receiver // for non-static native wrapper frames. ByteSize _native_receiver_sp_offset; ByteSize _native_basic_lock_sp_offset; friend class nmethodLocker; // For native wrappers nmethod(methodOop method, int nmethod_size, CodeOffsets* offsets, CodeBuffer *code_buffer, int frame_size, ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */ ByteSize basic_lock_sp_offset, /* synchronized natives only */ OopMapSet* oop_maps); #ifdef HAVE_DTRACE_H // For native wrappers nmethod(methodOop method, int nmethod_size, CodeOffsets* offsets, CodeBuffer *code_buffer, int frame_size); #endif // def HAVE_DTRACE_H // Creation support nmethod(methodOop method, int nmethod_size, int compile_id, int entry_bci, CodeOffsets* offsets, int orig_pc_offset, DebugInformationRecorder *recorder, Dependencies* dependencies, CodeBuffer *code_buffer, int frame_size, OopMapSet* oop_maps, ExceptionHandlerTable* handler_table, ImplicitExceptionTable* nul_chk_table, AbstractCompiler* compiler, int comp_level); // helper methods void* operator new(size_t size, int nmethod_size); const char* reloc_string_for(u_char* begin, u_char* end); // Returns true if this thread changed the state of the nmethod or // false if another thread performed the transition. bool make_not_entrant_or_zombie(unsigned int state); void inc_decompile_count(); // Used to manipulate the exception cache void add_exception_cache_entry(ExceptionCache* new_entry); ExceptionCache* exception_cache_entry_for_exception(Handle exception); // Inform external interfaces that a compiled method has been unloaded void post_compiled_method_unload(); // Initailize fields to their default values void init_defaults(); public: // create nmethod with entry_bci static nmethod* new_nmethod(methodHandle method, int compile_id, int entry_bci, CodeOffsets* offsets, int orig_pc_offset, DebugInformationRecorder* recorder, Dependencies* dependencies, CodeBuffer *code_buffer, int frame_size, OopMapSet* oop_maps, ExceptionHandlerTable* handler_table, ImplicitExceptionTable* nul_chk_table, AbstractCompiler* compiler, int comp_level); static nmethod* new_native_nmethod(methodHandle method, CodeBuffer *code_buffer, int vep_offset, int frame_complete, int frame_size, ByteSize receiver_sp_offset, ByteSize basic_lock_sp_offset, OopMapSet* oop_maps); #ifdef HAVE_DTRACE_H // The method we generate for a dtrace probe has to look // like an nmethod as far as the rest of the system is concerned // which is somewhat unfortunate. static nmethod* new_dtrace_nmethod(methodHandle method, CodeBuffer *code_buffer, int vep_offset, int trap_offset, int frame_complete, int frame_size); int trap_offset() const { return _trap_offset; } address trap_address() const { return insts_begin() + _trap_offset; } #endif // def HAVE_DTRACE_H // accessors methodOop method() const { return _method; } AbstractCompiler* compiler() const { return _compiler; } #ifndef PRODUCT bool has_debug_info() const { return _has_debug_info; } void set_has_debug_info(bool f) { _has_debug_info = false; } #endif // NOT PRODUCT // type info bool is_nmethod() const { return true; } bool is_java_method() const { return !method()->is_native(); } bool is_native_method() const { return method()->is_native(); } bool is_osr_method() const { return _entry_bci != InvocationEntryBci; } bool is_compiled_by_c1() const; bool is_compiled_by_c2() const; bool is_compiled_by_shark() const; // boundaries for different parts address consts_begin () const { return header_begin() + _consts_offset ; } address consts_end () const { return header_begin() + code_offset() ; } address insts_begin () const { return header_begin() + code_offset() ; } address insts_end () const { return header_begin() + _stub_offset ; } address stub_begin () const { return header_begin() + _stub_offset ; } address stub_end () const { return header_begin() + _oops_offset ; } address exception_begin () const { return header_begin() + _exception_offset ; } address deopt_handler_begin () const { return header_begin() + _deoptimize_offset ; } address deopt_mh_handler_begin() const { return header_begin() + _deoptimize_mh_offset ; } address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; } oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; } oop* oops_end () const { return (oop*) (header_begin() + _scopes_data_offset) ; } address scopes_data_begin () const { return header_begin() + _scopes_data_offset ; } address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; } PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); } PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; } address dependencies_begin () const { return header_begin() + _dependencies_offset ; } address dependencies_end () const { return header_begin() + _handler_table_offset ; } address handler_table_begin () const { return header_begin() + _handler_table_offset ; } address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; } address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; } address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; } // Sizes int consts_size () const { return consts_end () - consts_begin (); } int insts_size () const { return insts_end () - insts_begin (); } int stub_size () const { return stub_end () - stub_begin (); } int oops_size () const { return (address) oops_end () - (address) oops_begin (); } int scopes_data_size () const { return scopes_data_end () - scopes_data_begin (); } int scopes_pcs_size () const { return (intptr_t) scopes_pcs_end () - (intptr_t) scopes_pcs_begin (); } int dependencies_size () const { return dependencies_end () - dependencies_begin (); } int handler_table_size() const { return handler_table_end() - handler_table_begin(); } int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); } int total_size () const; // Containment bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); } bool insts_contains (address addr) const { return insts_begin () <= addr && addr < insts_end (); } bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); } bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); } bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); } bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); } bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); } bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); } // entry points address entry_point() const { return _entry_point; } // normal entry point address verified_entry_point() const { return _verified_entry_point; } // if klass is correct // flag accessing and manipulation bool is_in_use() const { return _state == alive; } bool is_alive() const { return _state == alive || _state == not_entrant; } bool is_not_entrant() const { return _state == not_entrant; } bool is_zombie() const { return _state == zombie; } bool is_unloaded() const { return _state == unloaded; } // Make the nmethod non entrant. The nmethod will continue to be // alive. It is used when an uncommon trap happens. Returns true // if this thread changed the state of the nmethod or false if // another thread performed the transition. bool make_not_entrant() { return make_not_entrant_or_zombie(not_entrant); } bool make_zombie() { return make_not_entrant_or_zombie(zombie); } // used by jvmti to track if the unload event has been reported bool unload_reported() { return _unload_reported; } void set_unload_reported() { _unload_reported = true; } bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; } void mark_for_deoptimization() { _marked_for_deoptimization = true; } void make_unloaded(BoolObjectClosure* is_alive, oop cause); bool has_dependencies() { return dependencies_size() != 0; } void flush_dependencies(BoolObjectClosure* is_alive); bool has_flushed_dependencies() { return _has_flushed_dependencies; } void set_has_flushed_dependencies() { assert(!has_flushed_dependencies(), "should only happen once"); _has_flushed_dependencies = 1; } bool is_marked_for_reclamation() const { return _marked_for_reclamation; } void mark_for_reclamation() { _marked_for_reclamation = 1; } bool has_unsafe_access() const { return _has_unsafe_access; } void set_has_unsafe_access(bool z) { _has_unsafe_access = z; } bool has_method_handle_invokes() const { return _has_method_handle_invokes; } void set_has_method_handle_invokes(bool z) { _has_method_handle_invokes = z; } bool is_speculatively_disconnected() const { return _speculatively_disconnected; } void set_speculatively_disconnected(bool z) { _speculatively_disconnected = z; } int comp_level() const { return _comp_level; } // Support for oops in scopes and relocs: // Note: index 0 is reserved for null. oop oop_at(int index) const { return index == 0 ? (oop) NULL: *oop_addr_at(index); } oop* oop_addr_at(int index) const { // for GC // relocation indexes are biased by 1 (because 0 is reserved) assert(index > 0 && index <= oops_size(), "must be a valid non-zero index"); assert(!_oops_are_stale, "oops are stale"); return &oops_begin()[index - 1]; } void copy_oops(GrowableArray* oops); // Relocation support private: void fix_oop_relocations(address begin, address end, bool initialize_immediates); inline void initialize_immediate_oop(oop* dest, jobject handle); public: void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); } void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); } bool is_at_poll_return(address pc); bool is_at_poll_or_poll_return(address pc); // Non-perm oop support bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; } protected: enum { npl_on_list = 0x01, npl_marked = 0x10 }; void set_on_scavenge_root_list() { _scavenge_root_state = npl_on_list; } void clear_on_scavenge_root_list() { _scavenge_root_state = 0; } // assertion-checking and pruning logic uses the bits of _scavenge_root_state #ifndef PRODUCT void set_scavenge_root_marked() { _scavenge_root_state |= npl_marked; } void clear_scavenge_root_marked() { _scavenge_root_state &= ~npl_marked; } bool scavenge_root_not_marked() { return (_scavenge_root_state &~ npl_on_list) == 0; } // N.B. there is no positive marked query, and we only use the not_marked query for asserts. #endif //PRODUCT nmethod* scavenge_root_link() const { return _scavenge_root_link; } void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; } nmethod* saved_nmethod_link() const { return _saved_nmethod_link; } void set_saved_nmethod_link(nmethod *n) { _saved_nmethod_link = n; } public: // Sweeper support long stack_traversal_mark() { return _stack_traversal_mark; } void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; } // Exception cache support ExceptionCache* exception_cache() const { return _exception_cache; } void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; } address handler_for_exception_and_pc(Handle exception, address pc); void add_handler_for_exception_and_pc(Handle exception, address pc, address handler); void remove_from_exception_cache(ExceptionCache* ec); // implicit exceptions support address continuation_for_implicit_exception(address pc); // On-stack replacement support int osr_entry_bci() const { assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod"); return _entry_bci; } address osr_entry() const { assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod"); return _osr_entry_point; } void invalidate_osr_method(); nmethod* osr_link() const { return _osr_link; } void set_osr_link(nmethod *n) { _osr_link = n; } // tells whether frames described by this nmethod can be deoptimized // note: native wrappers cannot be deoptimized. bool can_be_deoptimized() const { return is_java_method(); } // Inline cache support void clear_inline_caches(); void cleanup_inline_caches(); bool inlinecache_check_contains(address addr) const { return (addr >= code_begin() && addr < verified_entry_point()); } // unlink and deallocate this nmethod // Only NMethodSweeper class is expected to use this. NMethodSweeper is not // expected to use any other private methods/data in this class. protected: void flush(); public: // When true is returned, it is unsafe to remove this nmethod even if // it is a zombie, since the VM or the ServiceThread might still be // using it. bool is_locked_by_vm() const { return _lock_count >0; } // See comment at definition of _last_seen_on_stack void mark_as_seen_on_stack(); bool can_not_entrant_be_converted(); // Evolution support. We make old (discarded) compiled methods point to new methodOops. void set_method(methodOop method) { _method = method; } // GC support void do_unloading(BoolObjectClosure* is_alive, OopClosure* keep_alive, bool unloading_occurred); bool can_unload(BoolObjectClosure* is_alive, OopClosure* keep_alive, oop* root, bool unloading_occurred); void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f); void oops_do(OopClosure* f) { oops_do(f, false); } void oops_do(OopClosure* f, bool do_strong_roots_only); bool detect_scavenge_root_oops(); void verify_scavenge_root_oops() PRODUCT_RETURN; bool test_set_oops_do_mark(); static void oops_do_marking_prologue(); static void oops_do_marking_epilogue(); static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; } DEBUG_ONLY(bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }) // ScopeDesc for an instruction ScopeDesc* scope_desc_at(address pc); private: ScopeDesc* scope_desc_in(address begin, address end); address* orig_pc_addr(const frame* fr) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); } PcDesc* find_pc_desc_internal(address pc, bool approximate); PcDesc* find_pc_desc(address pc, bool approximate) { PcDesc* desc = _pc_desc_cache.last_pc_desc(); if (desc != NULL && desc->pc_offset() == pc - code_begin()) { return desc; } return find_pc_desc_internal(pc, approximate); } public: // ScopeDesc retrieval operation PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); } // pc_desc_near returns the first PcDesc at or after the givne pc. PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); } public: // copying of debugging information void copy_scopes_pcs(PcDesc* pcs, int count); void copy_scopes_data(address buffer, int size); // Deopt // Return true is the PC is one would expect if the frame is being deopted. bool is_deopt_pc (address pc) { return is_deopt_entry(pc) || is_deopt_mh_entry(pc); } bool is_deopt_entry (address pc) { return pc == deopt_handler_begin(); } bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); } // Accessor/mutator for the original pc of a frame before a frame was deopted. address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); } void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; } static address get_deopt_original_pc(const frame* fr); // MethodHandle bool is_method_handle_return(address return_pc); // jvmti support: void post_compiled_method_load_event(); jmethodID get_and_cache_jmethod_id(); // verify operations void verify(); void verify_scopes(); void verify_interrupt_point(address interrupt_point); // print compilation helper static void print_compilation(outputStream *st, const char *method_name, const char *title, methodOop method, bool is_blocking, int compile_id, int bci, int comp_level); // printing support void print() const; void print_code(); void print_relocations() PRODUCT_RETURN; void print_pcs() PRODUCT_RETURN; void print_scopes() PRODUCT_RETURN; void print_dependencies() PRODUCT_RETURN; void print_value_on(outputStream* st) const PRODUCT_RETURN; void print_calls(outputStream* st) PRODUCT_RETURN; void print_handler_table() PRODUCT_RETURN; void print_nul_chk_table() PRODUCT_RETURN; void print_nmethod(bool print_code); // need to re-define this from CodeBlob else the overload hides it virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); } void print_on(outputStream* st, const char* title) const; // Logging void log_identity(xmlStream* log) const; void log_new_nmethod() const; void log_state_change() const; // Prints block-level comments, including nmethod specific block labels: virtual void print_block_comment(outputStream* stream, address block_begin) { print_nmethod_labels(stream, block_begin); CodeBlob::print_block_comment(stream, block_begin); } void print_nmethod_labels(outputStream* stream, address block_begin); // Prints a comment for one native instruction (reloc info, pc desc) void print_code_comment_on(outputStream* st, int column, address begin, address end); static void print_statistics() PRODUCT_RETURN; // Compiler task identification. Note that all OSR methods // are numbered in an independent sequence if CICountOSR is true, // and native method wrappers are also numbered independently if // CICountNative is true. int compile_id() const { return _compile_id; } const char* compile_kind() const; // For debugging // CompiledIC* IC_at(char* p) const; // PrimitiveIC* primitiveIC_at(char* p) const; oop embeddedOop_at(address p); // tells if any of this method's dependencies have been invalidated // (this is expensive!) bool check_all_dependencies(); // tells if this compiled method is dependent on the given changes, // and the changes have invalidated it bool check_dependency_on(DepChange& changes); // Evolution support. Tells if this compiled method is dependent on any of // methods m() of class dependee, such that if m() in dependee is replaced, // this compiled method will have to be deoptimized. bool is_evol_dependent_on(klassOop dependee); // Fast breakpoint support. Tells if this compiled method is // dependent on the given method. Returns true if this nmethod // corresponds to the given method as well. bool is_dependent_on_method(methodOop dependee); // is it ok to patch at address? bool is_patchable_at(address instr_address); // UseBiasedLocking support ByteSize native_receiver_sp_offset() { return _native_receiver_sp_offset; } ByteSize native_basic_lock_sp_offset() { return _native_basic_lock_sp_offset; } // support for code generation static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); } static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); } static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); } }; // Locks an nmethod so its code will not get removed and it will not // be made into a zombie, even if it is a not_entrant method. After the // nmethod becomes a zombie, if CompiledMethodUnload event processing // needs to be done, then lock_nmethod() is used directly to keep the // generated code from being reused too early. class nmethodLocker : public StackObj { nmethod* _nm; public: // note: nm can be NULL // Only JvmtiDeferredEvent::compiled_method_unload_event() // should pass zombie_ok == true. static void lock_nmethod(nmethod* nm, bool zombie_ok = false); static void unlock_nmethod(nmethod* nm); // (ditto) nmethodLocker(address pc); // derive nm from pc nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); } nmethodLocker() { _nm = NULL; } ~nmethodLocker() { unlock_nmethod(_nm); } nmethod* code() { return _nm; } void set_code(nmethod* new_nm) { unlock_nmethod(_nm); // note: This works even if _nm==new_nm. _nm = new_nm; lock_nmethod(_nm); } }; #endif // SHARE_VM_CODE_NMETHOD_HPP