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src/share/vm/code/nmethod.hpp@53eec13fbaa5 (annotated)

src/share/vm/code/nmethod.hpp

Thu, 26 Jul 2018 16:04:06 +0800

author

aoqi

date

Thu, 26 Jul 2018 16:04:06 +0800

changeset 9203

53eec13fbaa5

parent 8856

ac27a9c85bea

permissions

-rw-r--r--

Merge

aoqi@0	1	/*
dbuck@8734	2	* Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation.
aoqi@0	8	*
aoqi@0	9	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	12	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	13	* accompanied this code).
aoqi@0	14	*
aoqi@0	15	* You should have received a copy of the GNU General Public License version
aoqi@0	16	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	18	*
aoqi@0	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	20	* or visit www.oracle.com if you need additional information or have any
aoqi@0	21	* questions.
aoqi@0	22	*
aoqi@0	23	*/
aoqi@0	24
aoqi@0	25	#ifndef SHARE_VM_CODE_NMETHOD_HPP
aoqi@0	26	#define SHARE_VM_CODE_NMETHOD_HPP
aoqi@0	27
aoqi@0	28	#include "code/codeBlob.hpp"
aoqi@0	29	#include "code/pcDesc.hpp"
aoqi@0	30	#include "oops/metadata.hpp"
aoqi@0	31
aoqi@0	32	// This class is used internally by nmethods, to cache
aoqi@0	33	// exception/pc/handler information.
aoqi@0	34
aoqi@0	35	class ExceptionCache : public CHeapObj<mtCode> {
aoqi@0	36	friend class VMStructs;
aoqi@0	37	private:
aoqi@0	38	enum { cache_size = 16 };
aoqi@0	39	Klass* _exception_type;
aoqi@0	40	address _pc[cache_size];
aoqi@0	41	address _handler[cache_size];
dbuck@8734	42	volatile int _count;
aoqi@0	43	ExceptionCache* _next;
aoqi@0	44
aoqi@0	45	address pc_at(int index) { assert(index >= 0 && index < count(),""); return _pc[index]; }
aoqi@0	46	void set_pc_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
aoqi@0	47	address handler_at(int index) { assert(index >= 0 && index < count(),""); return _handler[index]; }
aoqi@0	48	void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
dbuck@8734	49	int count() { return OrderAccess::load_acquire(&_count); }
dbuck@8734	50	// increment_count is only called under lock, but there may be concurrent readers.
dbuck@8734	51	void increment_count() { OrderAccess::release_store(&_count, _count + 1); }
aoqi@0	52
aoqi@0	53	public:
aoqi@0	54
aoqi@0	55	ExceptionCache(Handle exception, address pc, address handler);
aoqi@0	56
aoqi@0	57	Klass* exception_type() { return _exception_type; }
aoqi@0	58	ExceptionCache* next() { return _next; }
aoqi@0	59	void set_next(ExceptionCache *ec) { _next = ec; }
aoqi@0	60
aoqi@0	61	address match(Handle exception, address pc);
aoqi@0	62	bool match_exception_with_space(Handle exception) ;
aoqi@0	63	address test_address(address addr);
aoqi@0	64	bool add_address_and_handler(address addr, address handler) ;
aoqi@0	65	};
aoqi@0	66
aoqi@0	67
aoqi@0	68	// cache pc descs found in earlier inquiries
aoqi@0	69	class PcDescCache VALUE_OBJ_CLASS_SPEC {
aoqi@0	70	friend class VMStructs;
aoqi@0	71	private:
aoqi@0	72	enum { cache_size = 4 };
mdoerr@6941	73	// The array elements MUST be volatile! Several threads may modify
mdoerr@6941	74	// and read from the cache concurrently. find_pc_desc_internal has
mdoerr@6941	75	// returned wrong results. C++ compiler (namely xlC12) may duplicate
mdoerr@6941	76	// C++ field accesses if the elements are not volatile.
mdoerr@6941	77	typedef PcDesc* PcDescPtr;
mdoerr@6941	78	volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
aoqi@0	79	public:
aoqi@0	80	PcDescCache() { debug_only(_pc_descs[0] = NULL); }
aoqi@0	81	void reset_to(PcDesc* initial_pc_desc);
aoqi@0	82	PcDesc* find_pc_desc(int pc_offset, bool approximate);
aoqi@0	83	void add_pc_desc(PcDesc* pc_desc);
aoqi@0	84	PcDesc* last_pc_desc() { return _pc_descs[0]; }
aoqi@0	85	};
aoqi@0	86
aoqi@0	87
aoqi@0	88	// nmethods (native methods) are the compiled code versions of Java methods.
aoqi@0	89	//
aoqi@0	90	// An nmethod contains:
aoqi@0	91	// - header (the nmethod structure)
aoqi@0	92	// [Relocation]
aoqi@0	93	// - relocation information
aoqi@0	94	// - constant part (doubles, longs and floats used in nmethod)
aoqi@0	95	// - oop table
aoqi@0	96	// [Code]
aoqi@0	97	// - code body
aoqi@0	98	// - exception handler
aoqi@0	99	// - stub code
aoqi@0	100	// [Debugging information]
aoqi@0	101	// - oop array
aoqi@0	102	// - data array
aoqi@0	103	// - pcs
aoqi@0	104	// [Exception handler table]
aoqi@0	105	// - handler entry point array
aoqi@0	106	// [Implicit Null Pointer exception table]
aoqi@0	107	// - implicit null table array
aoqi@0	108
aoqi@0	109	class Dependencies;
aoqi@0	110	class ExceptionHandlerTable;
aoqi@0	111	class ImplicitExceptionTable;
aoqi@0	112	class AbstractCompiler;
aoqi@0	113	class xmlStream;
aoqi@0	114
aoqi@0	115	class nmethod : public CodeBlob {
aoqi@0	116	friend class VMStructs;
aoqi@0	117	friend class NMethodSweeper;
aoqi@0	118	friend class CodeCache; // scavengable oops
aoqi@0	119	private:
stefank@6992	120
stefank@6992	121	// GC support to help figure out if an nmethod has been
stefank@6992	122	// cleaned/unloaded by the current GC.
stefank@6992	123	static unsigned char _global_unloading_clock;
stefank@6992	124
aoqi@0	125	// Shared fields for all nmethod's
aoqi@0	126	Method* _method;
aoqi@0	127	int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
aoqi@0	128	jmethodID _jmethod_id; // Cache of method()->jmethod_id()
aoqi@0	129
aoqi@0	130	// To support simple linked-list chaining of nmethods:
aoqi@0	131	nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
stefank@6992	132
stefank@6992	133	union {
stefank@6992	134	// Used by G1 to chain nmethods.
stefank@6992	135	nmethod* _unloading_next;
stefank@6992	136	// Used by non-G1 GCs to chain nmethods.
stefank@6992	137	nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
stefank@6992	138	};
aoqi@0	139
aoqi@0	140	static nmethod* volatile _oops_do_mark_nmethods;
aoqi@0	141	nmethod* volatile _oops_do_mark_link;
aoqi@0	142
aoqi@0	143	AbstractCompiler* _compiler; // The compiler which compiled this nmethod
aoqi@0	144
aoqi@0	145	// offsets for entry points
aoqi@0	146	address _entry_point; // entry point with class check
aoqi@0	147	address _verified_entry_point; // entry point without class check
aoqi@0	148	address _osr_entry_point; // entry point for on stack replacement
aoqi@0	149
aoqi@0	150	// Offsets for different nmethod parts
aoqi@0	151	int _exception_offset;
aoqi@0	152	// All deoptee's will resume execution at this location described by
aoqi@0	153	// this offset.
aoqi@0	154	int _deoptimize_offset;
aoqi@0	155	// All deoptee's at a MethodHandle call site will resume execution
aoqi@0	156	// at this location described by this offset.
aoqi@0	157	int _deoptimize_mh_offset;
aoqi@0	158	// Offset of the unwind handler if it exists
aoqi@0	159	int _unwind_handler_offset;
aoqi@0	160
aoqi@0	161	#ifdef HAVE_DTRACE_H
aoqi@0	162	int _trap_offset;
aoqi@0	163	#endif // def HAVE_DTRACE_H
aoqi@0	164	int _consts_offset;
aoqi@0	165	int _stub_offset;
aoqi@0	166	int _oops_offset; // offset to where embedded oop table begins (inside data)
aoqi@0	167	int _metadata_offset; // embedded meta data table
aoqi@0	168	int _scopes_data_offset;
aoqi@0	169	int _scopes_pcs_offset;
aoqi@0	170	int _dependencies_offset;
aoqi@0	171	int _handler_table_offset;
aoqi@0	172	int _nul_chk_table_offset;
aoqi@0	173	int _nmethod_end_offset;
aoqi@0	174
aoqi@0	175	// location in frame (offset for sp) that deopt can store the original
aoqi@0	176	// pc during a deopt.
aoqi@0	177	int _orig_pc_offset;
aoqi@0	178
aoqi@0	179	int _compile_id; // which compilation made this nmethod
aoqi@0	180	int _comp_level; // compilation level
aoqi@0	181
aoqi@0	182	// protected by CodeCache_lock
aoqi@0	183	bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
aoqi@0	184
aoqi@0	185	bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper)
aoqi@0	186	bool _marked_for_deoptimization; // Used for stack deoptimization
aoqi@0	187
aoqi@0	188	// used by jvmti to track if an unload event has been posted for this nmethod.
aoqi@0	189	bool _unload_reported;
aoqi@0	190
aoqi@0	191	// set during construction
aoqi@0	192	unsigned int _has_unsafe_access:1; // May fault due to unsafe access.
aoqi@0	193	unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
aoqi@0	194	unsigned int _lazy_critical_native:1; // Lazy JNI critical native
aoqi@0	195	unsigned int _has_wide_vectors:1; // Preserve wide vectors at safepoints
aoqi@0	196
aoqi@0	197	// Protected by Patching_lock
aoqi@0	198	volatile unsigned char _state; // {alive, not_entrant, zombie, unloaded}
aoqi@0	199
stefank@6992	200	volatile unsigned char _unloading_clock; // Incremented after GC unloaded/cleaned the nmethod
stefank@6992	201
aoqi@0	202	#ifdef ASSERT
aoqi@0	203	bool _oops_are_stale; // indicates that it's no longer safe to access oops section
aoqi@0	204	#endif
aoqi@0	205
aoqi@0	206	enum { in_use = 0, // executable nmethod
aoqi@0	207	not_entrant = 1, // marked for deoptimization but activations may still exist,
aoqi@0	208	// will be transformed to zombie when all activations are gone
aoqi@0	209	zombie = 2, // no activations exist, nmethod is ready for purge
aoqi@0	210	unloaded = 3 }; // there should be no activations, should not be called,
aoqi@0	211	// will be transformed to zombie immediately
aoqi@0	212
aoqi@0	213	jbyte _scavenge_root_state;
aoqi@0	214
aoqi@0	215	#if INCLUDE_RTM_OPT
aoqi@0	216	// RTM state at compile time. Used during deoptimization to decide
aoqi@0	217	// whether to restart collecting RTM locking abort statistic again.
aoqi@0	218	RTMState _rtm_state;
aoqi@0	219	#endif
aoqi@0	220
aoqi@0	221	// Nmethod Flushing lock. If non-zero, then the nmethod is not removed
aoqi@0	222	// and is not made into a zombie. However, once the nmethod is made into
aoqi@0	223	// a zombie, it will be locked one final time if CompiledMethodUnload
aoqi@0	224	// event processing needs to be done.
aoqi@0	225	jint _lock_count;
aoqi@0	226
aoqi@0	227	// not_entrant method removal. Each mark_sweep pass will update
aoqi@0	228	// this mark to current sweep invocation count if it is seen on the
aoqi@0	229	// stack. An not_entrant method can be removed when there are no
aoqi@0	230	// more activations, i.e., when the _stack_traversal_mark is less than
aoqi@0	231	// current sweep traversal index.
aoqi@0	232	long _stack_traversal_mark;
aoqi@0	233
aoqi@0	234	// The _hotness_counter indicates the hotness of a method. The higher
aoqi@0	235	// the value the hotter the method. The hotness counter of a nmethod is
aoqi@0	236	// set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
aoqi@0	237	// is active while stack scanning (mark_active_nmethods()). The hotness
aoqi@0	238	// counter is decreased (by 1) while sweeping.
aoqi@0	239	int _hotness_counter;
aoqi@0	240
dbuck@8734	241	ExceptionCache * volatile _exception_cache;
aoqi@0	242	PcDescCache _pc_desc_cache;
aoqi@0	243
aoqi@0	244	// These are used for compiled synchronized native methods to
aoqi@0	245	// locate the owner and stack slot for the BasicLock so that we can
aoqi@0	246	// properly revoke the bias of the owner if necessary. They are
aoqi@0	247	// needed because there is no debug information for compiled native
aoqi@0	248	// wrappers and the oop maps are insufficient to allow
aoqi@0	249	// frame::retrieve_receiver() to work. Currently they are expected
aoqi@0	250	// to be byte offsets from the Java stack pointer for maximum code
aoqi@0	251	// sharing between platforms. Note that currently biased locking
aoqi@0	252	// will never cause Class instances to be biased but this code
aoqi@0	253	// handles the static synchronized case as well.
aoqi@0	254	// JVMTI's GetLocalInstance() also uses these offsets to find the receiver
aoqi@0	255	// for non-static native wrapper frames.
aoqi@0	256	ByteSize _native_receiver_sp_offset;
aoqi@0	257	ByteSize _native_basic_lock_sp_offset;
aoqi@0	258
aoqi@0	259	friend class nmethodLocker;
aoqi@0	260
aoqi@0	261	// For native wrappers
aoqi@0	262	nmethod(Method* method,
aoqi@0	263	int nmethod_size,
aoqi@0	264	int compile_id,
aoqi@0	265	CodeOffsets* offsets,
aoqi@0	266	CodeBuffer *code_buffer,
aoqi@0	267	int frame_size,
aoqi@0	268	ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
aoqi@0	269	ByteSize basic_lock_sp_offset, /* synchronized natives only */
aoqi@0	270	OopMapSet* oop_maps);
aoqi@0	271
aoqi@0	272	#ifdef HAVE_DTRACE_H
aoqi@0	273	// For native wrappers
aoqi@0	274	nmethod(Method* method,
aoqi@0	275	int nmethod_size,
aoqi@0	276	CodeOffsets* offsets,
aoqi@0	277	CodeBuffer *code_buffer,
aoqi@0	278	int frame_size);
aoqi@0	279	#endif // def HAVE_DTRACE_H
aoqi@0	280
aoqi@0	281	// Creation support
aoqi@0	282	nmethod(Method* method,
aoqi@0	283	int nmethod_size,
aoqi@0	284	int compile_id,
aoqi@0	285	int entry_bci,
aoqi@0	286	CodeOffsets* offsets,
aoqi@0	287	int orig_pc_offset,
aoqi@0	288	DebugInformationRecorder *recorder,
aoqi@0	289	Dependencies* dependencies,
aoqi@0	290	CodeBuffer *code_buffer,
aoqi@0	291	int frame_size,
aoqi@0	292	OopMapSet* oop_maps,
aoqi@0	293	ExceptionHandlerTable* handler_table,
aoqi@0	294	ImplicitExceptionTable* nul_chk_table,
aoqi@0	295	AbstractCompiler* compiler,
aoqi@0	296	int comp_level);
aoqi@0	297
aoqi@0	298	// helper methods
aoqi@0	299	void* operator new(size_t size, int nmethod_size) throw();
aoqi@0	300
aoqi@0	301	const char* reloc_string_for(u_char* begin, u_char* end);
aoqi@0	302	// Returns true if this thread changed the state of the nmethod or
aoqi@0	303	// false if another thread performed the transition.
aoqi@0	304	bool make_not_entrant_or_zombie(unsigned int state);
aoqi@0	305	void inc_decompile_count();
aoqi@0	306
aoqi@0	307	// Used to manipulate the exception cache
aoqi@0	308	void add_exception_cache_entry(ExceptionCache* new_entry);
aoqi@0	309	ExceptionCache* exception_cache_entry_for_exception(Handle exception);
aoqi@0	310
aoqi@0	311	// Inform external interfaces that a compiled method has been unloaded
aoqi@0	312	void post_compiled_method_unload();
aoqi@0	313
aoqi@0	314	// Initailize fields to their default values
aoqi@0	315	void init_defaults();
aoqi@0	316
aoqi@0	317	public:
aoqi@0	318	// create nmethod with entry_bci
aoqi@0	319	static nmethod* new_nmethod(methodHandle method,
aoqi@0	320	int compile_id,
aoqi@0	321	int entry_bci,
aoqi@0	322	CodeOffsets* offsets,
aoqi@0	323	int orig_pc_offset,
aoqi@0	324	DebugInformationRecorder* recorder,
aoqi@0	325	Dependencies* dependencies,
aoqi@0	326	CodeBuffer *code_buffer,
aoqi@0	327	int frame_size,
aoqi@0	328	OopMapSet* oop_maps,
aoqi@0	329	ExceptionHandlerTable* handler_table,
aoqi@0	330	ImplicitExceptionTable* nul_chk_table,
aoqi@0	331	AbstractCompiler* compiler,
aoqi@0	332	int comp_level);
aoqi@0	333
aoqi@0	334	static nmethod* new_native_nmethod(methodHandle method,
aoqi@0	335	int compile_id,
aoqi@0	336	CodeBuffer *code_buffer,
aoqi@0	337	int vep_offset,
aoqi@0	338	int frame_complete,
aoqi@0	339	int frame_size,
aoqi@0	340	ByteSize receiver_sp_offset,
aoqi@0	341	ByteSize basic_lock_sp_offset,
aoqi@0	342	OopMapSet* oop_maps);
aoqi@0	343
aoqi@0	344	#ifdef HAVE_DTRACE_H
aoqi@0	345	// The method we generate for a dtrace probe has to look
aoqi@0	346	// like an nmethod as far as the rest of the system is concerned
aoqi@0	347	// which is somewhat unfortunate.
aoqi@0	348	static nmethod* new_dtrace_nmethod(methodHandle method,
aoqi@0	349	CodeBuffer *code_buffer,
aoqi@0	350	int vep_offset,
aoqi@0	351	int trap_offset,
aoqi@0	352	int frame_complete,
aoqi@0	353	int frame_size);
aoqi@0	354
aoqi@0	355	int trap_offset() const { return _trap_offset; }
aoqi@0	356	address trap_address() const { return insts_begin() + _trap_offset; }
aoqi@0	357
aoqi@0	358	#endif // def HAVE_DTRACE_H
aoqi@0	359
aoqi@0	360	// accessors
aoqi@0	361	Method* method() const { return _method; }
aoqi@0	362	AbstractCompiler* compiler() const { return _compiler; }
aoqi@0	363
aoqi@0	364	// type info
aoqi@0	365	bool is_nmethod() const { return true; }
aoqi@0	366	bool is_java_method() const { return !method()->is_native(); }
aoqi@0	367	bool is_native_method() const { return method()->is_native(); }
aoqi@0	368	bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
aoqi@0	369
aoqi@0	370	bool is_compiled_by_c1() const;
aoqi@0	371	bool is_compiled_by_c2() const;
aoqi@0	372	bool is_compiled_by_shark() const;
aoqi@0	373
aoqi@0	374	// boundaries for different parts
aoqi@0	375	address consts_begin () const { return header_begin() + _consts_offset ; }
aoqi@0	376	address consts_end () const { return header_begin() + code_offset() ; }
aoqi@0	377	address insts_begin () const { return header_begin() + code_offset() ; }
aoqi@0	378	address insts_end () const { return header_begin() + _stub_offset ; }
aoqi@0	379	address stub_begin () const { return header_begin() + _stub_offset ; }
aoqi@0	380	address stub_end () const { return header_begin() + _oops_offset ; }
aoqi@0	381	address exception_begin () const { return header_begin() + _exception_offset ; }
aoqi@0	382	address deopt_handler_begin () const { return header_begin() + _deoptimize_offset ; }
aoqi@0	383	address deopt_mh_handler_begin() const { return header_begin() + _deoptimize_mh_offset ; }
aoqi@0	384	address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
aoqi@0	385	oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
aoqi@0	386	oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
aoqi@0	387
aoqi@0	388	Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
aoqi@0	389	Metadata** metadata_end () const { return (Metadata**) (header_begin() + _scopes_data_offset) ; }
aoqi@0	390
aoqi@0	391	address scopes_data_begin () const { return header_begin() + _scopes_data_offset ; }
aoqi@0	392	address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
aoqi@0	393	PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
aoqi@0	394	PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
aoqi@0	395	address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
aoqi@0	396	address dependencies_end () const { return header_begin() + _handler_table_offset ; }
aoqi@0	397	address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
aoqi@0	398	address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
aoqi@0	399	address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
aoqi@0	400	address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
aoqi@0	401
aoqi@0	402	// Sizes
aoqi@0	403	int consts_size () const { return consts_end () - consts_begin (); }
aoqi@0	404	int insts_size () const { return insts_end () - insts_begin (); }
aoqi@0	405	int stub_size () const { return stub_end () - stub_begin (); }
aoqi@0	406	int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
aoqi@0	407	int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
aoqi@0	408	int scopes_data_size () const { return scopes_data_end () - scopes_data_begin (); }
aoqi@0	409	int scopes_pcs_size () const { return (intptr_t) scopes_pcs_end () - (intptr_t) scopes_pcs_begin (); }
aoqi@0	410	int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
aoqi@0	411	int handler_table_size() const { return handler_table_end() - handler_table_begin(); }
aoqi@0	412	int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); }
aoqi@0	413
aoqi@0	414	int total_size () const;
aoqi@0	415
aoqi@0	416	void dec_hotness_counter() { _hotness_counter--; }
aoqi@0	417	void set_hotness_counter(int val) { _hotness_counter = val; }
aoqi@0	418	int hotness_counter() const { return _hotness_counter; }
aoqi@0	419
aoqi@0	420	// Containment
aoqi@0	421	bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); }
aoqi@0	422	bool insts_contains (address addr) const { return insts_begin () <= addr && addr < insts_end (); }
aoqi@0	423	bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); }
aoqi@0	424	bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
aoqi@0	425	bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
aoqi@0	426	bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
aoqi@0	427	bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
aoqi@0	428	bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
aoqi@0	429	bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
aoqi@0	430
aoqi@0	431	// entry points
aoqi@0	432	address entry_point() const { return _entry_point; } // normal entry point
aoqi@0	433	address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
aoqi@0	434
aoqi@0	435	// flag accessing and manipulation
aoqi@0	436	bool is_in_use() const { return _state == in_use; }
dbuck@8734	437	bool is_alive() const { unsigned char s = _state; return s == in_use || s == not_entrant; }
aoqi@0	438	bool is_not_entrant() const { return _state == not_entrant; }
aoqi@0	439	bool is_zombie() const { return _state == zombie; }
aoqi@0	440	bool is_unloaded() const { return _state == unloaded; }
aoqi@0	441
aoqi@0	442	#if INCLUDE_RTM_OPT
aoqi@0	443	// rtm state accessing and manipulating
aoqi@0	444	RTMState rtm_state() const { return _rtm_state; }
aoqi@0	445	void set_rtm_state(RTMState state) { _rtm_state = state; }
aoqi@0	446	#endif
aoqi@0	447
aoqi@0	448	// Make the nmethod non entrant. The nmethod will continue to be
aoqi@0	449	// alive. It is used when an uncommon trap happens. Returns true
aoqi@0	450	// if this thread changed the state of the nmethod or false if
aoqi@0	451	// another thread performed the transition.
iveresov@7146	452	bool make_not_entrant() {
iveresov@7146	453	assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
iveresov@7146	454	return make_not_entrant_or_zombie(not_entrant);
iveresov@7146	455	}
aoqi@0	456	bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
aoqi@0	457
aoqi@0	458	// used by jvmti to track if the unload event has been reported
aoqi@0	459	bool unload_reported() { return _unload_reported; }
aoqi@0	460	void set_unload_reported() { _unload_reported = true; }
aoqi@0	461
stefank@6992	462	void set_unloading_next(nmethod* next) { _unloading_next = next; }
stefank@6992	463	nmethod* unloading_next() { return _unloading_next; }
stefank@6992	464
stefank@6992	465	static unsigned char global_unloading_clock() { return _global_unloading_clock; }
stefank@6992	466	static void increase_unloading_clock();
stefank@6992	467
stefank@6992	468	void set_unloading_clock(unsigned char unloading_clock);
stefank@6992	469	unsigned char unloading_clock();
stefank@6992	470
aoqi@0	471	bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; }
aoqi@0	472	void mark_for_deoptimization() { _marked_for_deoptimization = true; }
aoqi@0	473
aoqi@0	474	void make_unloaded(BoolObjectClosure* is_alive, oop cause);
aoqi@0	475
aoqi@0	476	bool has_dependencies() { return dependencies_size() != 0; }
aoqi@0	477	void flush_dependencies(BoolObjectClosure* is_alive);
aoqi@0	478	bool has_flushed_dependencies() { return _has_flushed_dependencies; }
aoqi@0	479	void set_has_flushed_dependencies() {
aoqi@0	480	assert(!has_flushed_dependencies(), "should only happen once");
aoqi@0	481	_has_flushed_dependencies = 1;
aoqi@0	482	}
aoqi@0	483
aoqi@0	484	bool is_marked_for_reclamation() const { return _marked_for_reclamation; }
aoqi@0	485	void mark_for_reclamation() { _marked_for_reclamation = 1; }
aoqi@0	486
aoqi@0	487	bool has_unsafe_access() const { return _has_unsafe_access; }
aoqi@0	488	void set_has_unsafe_access(bool z) { _has_unsafe_access = z; }
aoqi@0	489
aoqi@0	490	bool has_method_handle_invokes() const { return _has_method_handle_invokes; }
aoqi@0	491	void set_has_method_handle_invokes(bool z) { _has_method_handle_invokes = z; }
aoqi@0	492
aoqi@0	493	bool is_lazy_critical_native() const { return _lazy_critical_native; }
aoqi@0	494	void set_lazy_critical_native(bool z) { _lazy_critical_native = z; }
aoqi@0	495
aoqi@0	496	bool has_wide_vectors() const { return _has_wide_vectors; }
aoqi@0	497	void set_has_wide_vectors(bool z) { _has_wide_vectors = z; }
aoqi@0	498
aoqi@0	499	int comp_level() const { return _comp_level; }
aoqi@0	500
aoqi@0	501	// Support for oops in scopes and relocs:
aoqi@0	502	// Note: index 0 is reserved for null.
aoqi@0	503	oop oop_at(int index) const { return index == 0 ? (oop) NULL: *oop_addr_at(index); }
aoqi@0	504	oop* oop_addr_at(int index) const { // for GC
aoqi@0	505	// relocation indexes are biased by 1 (because 0 is reserved)
aoqi@0	506	assert(index > 0 && index <= oops_size(), "must be a valid non-zero index");
aoqi@0	507	assert(!_oops_are_stale, "oops are stale");
aoqi@0	508	return &oops_begin()[index - 1];
aoqi@0	509	}
aoqi@0	510
aoqi@0	511	// Support for meta data in scopes and relocs:
aoqi@0	512	// Note: index 0 is reserved for null.
aoqi@0	513	Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
aoqi@0	514	Metadata** metadata_addr_at(int index) const { // for GC
aoqi@0	515	// relocation indexes are biased by 1 (because 0 is reserved)
aoqi@0	516	assert(index > 0 && index <= metadata_size(), "must be a valid non-zero index");
aoqi@0	517	return &metadata_begin()[index - 1];
aoqi@0	518	}
aoqi@0	519
aoqi@0	520	void copy_values(GrowableArray<jobject>* oops);
aoqi@0	521	void copy_values(GrowableArray<Metadata*>* metadata);
aoqi@0	522
aoqi@0	523	// Relocation support
aoqi@0	524	private:
aoqi@0	525	void fix_oop_relocations(address begin, address end, bool initialize_immediates);
aoqi@0	526	inline void initialize_immediate_oop(oop* dest, jobject handle);
aoqi@0	527
aoqi@0	528	public:
aoqi@0	529	void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
aoqi@0	530	void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
aoqi@0	531	void verify_oop_relocations();
aoqi@0	532
aoqi@0	533	bool is_at_poll_return(address pc);
aoqi@0	534	bool is_at_poll_or_poll_return(address pc);
aoqi@0	535
aoqi@0	536	// Scavengable oop support
aoqi@0	537	bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }
aoqi@0	538	protected:
aoqi@0	539	enum { sl_on_list = 0x01, sl_marked = 0x10 };
aoqi@0	540	void set_on_scavenge_root_list() { _scavenge_root_state = sl_on_list; }
aoqi@0	541	void clear_on_scavenge_root_list() { _scavenge_root_state = 0; }
aoqi@0	542	// assertion-checking and pruning logic uses the bits of _scavenge_root_state
aoqi@0	543	#ifndef PRODUCT
aoqi@0	544	void set_scavenge_root_marked() { _scavenge_root_state |= sl_marked; }
aoqi@0	545	void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; }
aoqi@0	546	bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_on_list) == 0; }
aoqi@0	547	// N.B. there is no positive marked query, and we only use the not_marked query for asserts.
aoqi@0	548	#endif //PRODUCT
aoqi@0	549	nmethod* scavenge_root_link() const { return _scavenge_root_link; }
aoqi@0	550	void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; }
aoqi@0	551
aoqi@0	552	public:
aoqi@0	553
aoqi@0	554	// Sweeper support
aoqi@0	555	long stack_traversal_mark() { return _stack_traversal_mark; }
aoqi@0	556	void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
aoqi@0	557
aoqi@0	558	// Exception cache support
dbuck@8734	559	// Note: _exception_cache may be read concurrently. We rely on memory_order_consume here.
aoqi@0	560	ExceptionCache* exception_cache() const { return _exception_cache; }
aoqi@0	561	void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; }
dbuck@8734	562	void release_set_exception_cache(ExceptionCache *ec) { OrderAccess::release_store_ptr(&_exception_cache, ec); }
aoqi@0	563	address handler_for_exception_and_pc(Handle exception, address pc);
aoqi@0	564	void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
stefank@6983	565	void clean_exception_cache(BoolObjectClosure* is_alive);
aoqi@0	566
aoqi@0	567	// implicit exceptions support
aoqi@0	568	address continuation_for_implicit_exception(address pc);
aoqi@0	569
aoqi@0	570	// On-stack replacement support
aoqi@0	571	int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
aoqi@0	572	address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
aoqi@0	573	void invalidate_osr_method();
aoqi@0	574	nmethod* osr_link() const { return _osr_link; }
aoqi@0	575	void set_osr_link(nmethod *n) { _osr_link = n; }
aoqi@0	576
aoqi@0	577	// tells whether frames described by this nmethod can be deoptimized
aoqi@0	578	// note: native wrappers cannot be deoptimized.
aoqi@0	579	bool can_be_deoptimized() const { return is_java_method(); }
aoqi@0	580
aoqi@0	581	// Inline cache support
aoqi@0	582	void clear_inline_caches();
thartmann@8073	583	void clear_ic_stubs();
aoqi@0	584	void cleanup_inline_caches();
aoqi@0	585	bool inlinecache_check_contains(address addr) const {
aoqi@0	586	return (addr >= code_begin() && addr < verified_entry_point());
aoqi@0	587	}
aoqi@0	588
stefank@6992	589	// Verify calls to dead methods have been cleaned.
stefank@6992	590	void verify_clean_inline_caches();
stefank@6992	591	// Verify and count cached icholder relocations.
stefank@6992	592	int verify_icholder_relocations();
aoqi@0	593	// Check that all metadata is still alive
aoqi@0	594	void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive);
aoqi@0	595
aoqi@0	596	// unlink and deallocate this nmethod
aoqi@0	597	// Only NMethodSweeper class is expected to use this. NMethodSweeper is not
aoqi@0	598	// expected to use any other private methods/data in this class.
aoqi@0	599
aoqi@0	600	protected:
aoqi@0	601	void flush();
aoqi@0	602
aoqi@0	603	public:
aoqi@0	604	// When true is returned, it is unsafe to remove this nmethod even if
aoqi@0	605	// it is a zombie, since the VM or the ServiceThread might still be
aoqi@0	606	// using it.
aoqi@0	607	bool is_locked_by_vm() const { return _lock_count >0; }
aoqi@0	608
aoqi@0	609	// See comment at definition of _last_seen_on_stack
aoqi@0	610	void mark_as_seen_on_stack();
thartmann@8075	611	bool can_convert_to_zombie();
aoqi@0	612
aoqi@0	613	// Evolution support. We make old (discarded) compiled methods point to new Method*s.
aoqi@0	614	void set_method(Method* method) { _method = method; }
aoqi@0	615
aoqi@0	616	// GC support
aoqi@0	617	void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
stefank@6992	618	// The parallel versions are used by G1.
stefank@6992	619	bool do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred);
stefank@6992	620	void do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred);
stefank@7333	621
stefank@7333	622	private:
stefank@6992	623	// Unload a nmethod if the *root object is dead.
aoqi@0	624	bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
stefank@7333	625	bool unload_if_dead_at(RelocIterator *iter_at_oop, BoolObjectClosure* is_alive, bool unloading_occurred);
aoqi@0	626
stefank@7333	627	void mark_metadata_on_stack_at(RelocIterator* iter_at_metadata);
stefank@7333	628	void mark_metadata_on_stack_non_relocs();
stefank@7333	629
stefank@7333	630	public:
aoqi@0	631	void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
aoqi@0	632	OopClosure* f);
aoqi@0	633	void oops_do(OopClosure* f) { oops_do(f, false); }
aoqi@0	634	void oops_do(OopClosure* f, bool allow_zombie);
aoqi@0	635	bool detect_scavenge_root_oops();
aoqi@0	636	void verify_scavenge_root_oops() PRODUCT_RETURN;
aoqi@0	637
aoqi@0	638	bool test_set_oops_do_mark();
aoqi@0	639	static void oops_do_marking_prologue();
aoqi@0	640	static void oops_do_marking_epilogue();
aoqi@0	641	static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
aoqi@0	642	bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
aoqi@0	643
aoqi@0	644	// ScopeDesc for an instruction
aoqi@0	645	ScopeDesc* scope_desc_at(address pc);
aoqi@0	646
aoqi@0	647	private:
aoqi@0	648	ScopeDesc* scope_desc_in(address begin, address end);
aoqi@0	649
aoqi@0	650	address* orig_pc_addr(const frame* fr) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); }
aoqi@0	651
aoqi@0	652	PcDesc* find_pc_desc_internal(address pc, bool approximate);
aoqi@0	653
aoqi@0	654	PcDesc* find_pc_desc(address pc, bool approximate) {
aoqi@0	655	PcDesc* desc = _pc_desc_cache.last_pc_desc();
aoqi@0	656	if (desc != NULL && desc->pc_offset() == pc - code_begin()) {
aoqi@0	657	return desc;
aoqi@0	658	}
aoqi@0	659	return find_pc_desc_internal(pc, approximate);
aoqi@0	660	}
aoqi@0	661
aoqi@0	662	public:
aoqi@0	663	// ScopeDesc retrieval operation
aoqi@0	664	PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); }
aoqi@0	665	// pc_desc_near returns the first PcDesc at or after the givne pc.
aoqi@0	666	PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
aoqi@0	667
aoqi@0	668	public:
aoqi@0	669	// copying of debugging information
aoqi@0	670	void copy_scopes_pcs(PcDesc* pcs, int count);
aoqi@0	671	void copy_scopes_data(address buffer, int size);
aoqi@0	672
aoqi@0	673	// Deopt
aoqi@0	674	// Return true is the PC is one would expect if the frame is being deopted.
aoqi@0	675	bool is_deopt_pc (address pc) { return is_deopt_entry(pc) || is_deopt_mh_entry(pc); }
aoqi@0	676	bool is_deopt_entry (address pc) { return pc == deopt_handler_begin(); }
aoqi@0	677	bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); }
aoqi@0	678	// Accessor/mutator for the original pc of a frame before a frame was deopted.
aoqi@0	679	address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
aoqi@0	680	void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
aoqi@0	681
aoqi@0	682	static address get_deopt_original_pc(const frame* fr);
aoqi@0	683
aoqi@0	684	// MethodHandle
aoqi@0	685	bool is_method_handle_return(address return_pc);
aoqi@0	686
aoqi@0	687	// jvmti support:
aoqi@0	688	void post_compiled_method_load_event();
aoqi@0	689	jmethodID get_and_cache_jmethod_id();
aoqi@0	690
aoqi@0	691	// verify operations
aoqi@0	692	void verify();
aoqi@0	693	void verify_scopes();
aoqi@0	694	void verify_interrupt_point(address interrupt_point);
aoqi@0	695
aoqi@0	696	// printing support
aoqi@0	697	void print() const;
aoqi@0	698	void print_code();
aoqi@0	699	void print_relocations() PRODUCT_RETURN;
aoqi@0	700	void print_pcs() PRODUCT_RETURN;
aoqi@0	701	void print_scopes() PRODUCT_RETURN;
aoqi@0	702	void print_dependencies() PRODUCT_RETURN;
aoqi@0	703	void print_value_on(outputStream* st) const PRODUCT_RETURN;
aoqi@0	704	void print_calls(outputStream* st) PRODUCT_RETURN;
aoqi@0	705	void print_handler_table() PRODUCT_RETURN;
aoqi@0	706	void print_nul_chk_table() PRODUCT_RETURN;
aoqi@0	707	void print_nmethod(bool print_code);
aoqi@0	708
aoqi@0	709	// need to re-define this from CodeBlob else the overload hides it
aoqi@0	710	virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
aoqi@0	711	void print_on(outputStream* st, const char* msg) const;
aoqi@0	712
aoqi@0	713	// Logging
aoqi@0	714	void log_identity(xmlStream* log) const;
aoqi@0	715	void log_new_nmethod() const;
aoqi@0	716	void log_state_change() const;
aoqi@0	717
aoqi@0	718	// Prints block-level comments, including nmethod specific block labels:
aoqi@0	719	virtual void print_block_comment(outputStream* stream, address block_begin) const {
aoqi@0	720	print_nmethod_labels(stream, block_begin);
aoqi@0	721	CodeBlob::print_block_comment(stream, block_begin);
aoqi@0	722	}
aoqi@0	723	void print_nmethod_labels(outputStream* stream, address block_begin) const;
aoqi@0	724
aoqi@0	725	// Prints a comment for one native instruction (reloc info, pc desc)
aoqi@0	726	void print_code_comment_on(outputStream* st, int column, address begin, address end);
aoqi@0	727	static void print_statistics() PRODUCT_RETURN;
aoqi@0	728
aoqi@0	729	// Compiler task identification. Note that all OSR methods
aoqi@0	730	// are numbered in an independent sequence if CICountOSR is true,
aoqi@0	731	// and native method wrappers are also numbered independently if
aoqi@0	732	// CICountNative is true.
aoqi@0	733	int compile_id() const { return _compile_id; }
aoqi@0	734	const char* compile_kind() const;
aoqi@0	735
aoqi@0	736	// For debugging
aoqi@0	737	// CompiledIC* IC_at(char* p) const;
aoqi@0	738	// PrimitiveIC* primitiveIC_at(char* p) const;
aoqi@0	739	oop embeddedOop_at(address p);
aoqi@0	740
aoqi@0	741	// tells if any of this method's dependencies have been invalidated
aoqi@0	742	// (this is expensive!)
aoqi@0	743	bool check_all_dependencies();
aoqi@0	744
aoqi@0	745	// tells if this compiled method is dependent on the given changes,
aoqi@0	746	// and the changes have invalidated it
aoqi@0	747	bool check_dependency_on(DepChange& changes);
aoqi@0	748
aoqi@0	749	// Evolution support. Tells if this compiled method is dependent on any of
aoqi@0	750	// methods m() of class dependee, such that if m() in dependee is replaced,
aoqi@0	751	// this compiled method will have to be deoptimized.
aoqi@0	752	bool is_evol_dependent_on(Klass* dependee);
aoqi@0	753
aoqi@0	754	// Fast breakpoint support. Tells if this compiled method is
aoqi@0	755	// dependent on the given method. Returns true if this nmethod
aoqi@0	756	// corresponds to the given method as well.
aoqi@0	757	bool is_dependent_on_method(Method* dependee);
aoqi@0	758
aoqi@0	759	// is it ok to patch at address?
aoqi@0	760	bool is_patchable_at(address instr_address);
aoqi@0	761
aoqi@0	762	// UseBiasedLocking support
aoqi@0	763	ByteSize native_receiver_sp_offset() {
aoqi@0	764	return _native_receiver_sp_offset;
aoqi@0	765	}
aoqi@0	766	ByteSize native_basic_lock_sp_offset() {
aoqi@0	767	return _native_basic_lock_sp_offset;
aoqi@0	768	}
aoqi@0	769
aoqi@0	770	// support for code generation
aoqi@0	771	static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
aoqi@0	772	static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
aoqi@0	773	static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); }
aoqi@0	774
aoqi@0	775	// RedefineClasses support. Mark metadata in nmethods as on_stack so that
aoqi@0	776	// redefine classes doesn't purge it.
aoqi@0	777	static void mark_on_stack(nmethod* nm) {
aoqi@0	778	nm->metadata_do(Metadata::mark_on_stack);
aoqi@0	779	}
aoqi@0	780	void metadata_do(void f(Metadata*));
aoqi@0	781	};
aoqi@0	782
aoqi@0	783	// Locks an nmethod so its code will not get removed and it will not
aoqi@0	784	// be made into a zombie, even if it is a not_entrant method. After the
aoqi@0	785	// nmethod becomes a zombie, if CompiledMethodUnload event processing
aoqi@0	786	// needs to be done, then lock_nmethod() is used directly to keep the
aoqi@0	787	// generated code from being reused too early.
aoqi@0	788	class nmethodLocker : public StackObj {
aoqi@0	789	nmethod* _nm;
aoqi@0	790
aoqi@0	791	public:
aoqi@0	792
aoqi@0	793	// note: nm can be NULL
aoqi@0	794	// Only JvmtiDeferredEvent::compiled_method_unload_event()
aoqi@0	795	// should pass zombie_ok == true.
aoqi@0	796	static void lock_nmethod(nmethod* nm, bool zombie_ok = false);
aoqi@0	797	static void unlock_nmethod(nmethod* nm); // (ditto)
aoqi@0	798
aoqi@0	799	nmethodLocker(address pc); // derive nm from pc
aoqi@0	800	nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
aoqi@0	801	nmethodLocker() { _nm = NULL; }
aoqi@0	802	~nmethodLocker() { unlock_nmethod(_nm); }
aoqi@0	803
aoqi@0	804	nmethod* code() { return _nm; }
aoqi@0	805	void set_code(nmethod* new_nm) {
aoqi@0	806	unlock_nmethod(_nm); // note: This works even if _nm==new_nm.
aoqi@0	807	_nm = new_nm;
aoqi@0	808	lock_nmethod(_nm);
aoqi@0	809	}
aoqi@0	810	};
aoqi@0	811
aoqi@0	812	#endif // SHARE_VM_CODE_NMETHOD_HPP