#ifndef SHARE_VM_CODE_NMETHOD_HPP

#define SHARE_VM_CODE_NMETHOD_HPP

#include "code/codeBlob.hpp"

#include "code/pcDesc.hpp"

class ExceptionCache : public CHeapObj<mtCode> {

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) ;

};

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]; }

};

class Dependencies;

class ExceptionHandlerTable;

class ImplicitExceptionTable;

class AbstractCompiler;

class xmlStream;

class nmethod : public CodeBlob {

friend class VMStructs;

friend class NMethodSweeper;

friend class CodeCache; // scavengable 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?

unsigned int _lazy_critical_native:1; // Lazy JNI critical native

unsigned int _has_wide_vectors:1; // Preserve wide vectors at safepoints

// 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;

// 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,

int compile_id,

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,

int compile_id,

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; }

// 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; }

bool is_lazy_critical_native() const { return _lazy_critical_native; }

void set_lazy_critical_native(bool z) { _lazy_critical_native = z; }

bool has_wide_vectors() const { return _has_wide_vectors; }

void set_has_wide_vectors(bool z) { _has_wide_vectors = 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<jobject>* 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); }

void verify_oop_relocations();

bool is_at_poll_return(address pc);

bool is_at_poll_or_poll_return(address pc);

// Scavengable oop support

bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }

protected:

enum { sl_on_list = 0x01, sl_marked = 0x10 };

void set_on_scavenge_root_list() { _scavenge_root_state = sl_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 |= sl_marked; }

void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; }

bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_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(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }

address osr_entry() const { assert(is_osr_method(), "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; }

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);

// 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* msg) 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) const {

print_nmethod_labels(stream, block_begin);

CodeBlob::print_block_comment(stream, block_begin);

}

void print_nmethod_labels(outputStream* stream, address block_begin) const;

// 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); }

};

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