6939930: exception unwind changes in 6919934 hurts compilation speed
Reviewed-by: twisti
/*
* Copyright 1997-2010 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
// This class is used internally by nmethods, to cache
// exception/pc/handler information.
class ExceptionCache : public CHeapObj {
friend class VMStructs;
private:
static address _unwind_handler;
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) ;
static address unwind_handler() { return _unwind_handler; }
};
// cache pc descs found in earlier inquiries
class PcDescCache VALUE_OBJ_CLASS_SPEC {
friend class VMStructs;
private:
enum { cache_size = 4 };
PcDesc* _last_pc_desc; // most recent pc_desc found
PcDesc* _pc_descs[cache_size]; // last cache_size pc_descs found
public:
PcDescCache() { debug_only(_last_pc_desc = 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 _last_pc_desc; }
};
// nmethods (native methods) are the compiled code versions of Java methods.
struct nmFlags {
friend class VMStructs;
unsigned int version:8; // version number (0 = first version)
unsigned int level:4; // optimization level
unsigned int age:4; // age (in # of sweep steps)
unsigned int state:2; // {alive, zombie, unloaded)
unsigned int isUncommonRecompiled:1; // recompiled because of uncommon trap?
unsigned int isToBeRecompiled:1; // to be recompiled as soon as it matures
unsigned int hasFlushedDependencies:1; // Used for maintenance of dependencies
unsigned int markedForReclamation:1; // Used by NMethodSweeper
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 speculatively_disconnected:1; // Marked for potential unload
void clear();
};
// A nmethod contains:
// - header (the nmethod structure)
// [Relocation]
// - relocation information
// - constant part (doubles, longs and floats used in nmethod)
// [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
static int _zombie_instruction_size;
methodOop _method;
int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
// 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 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 _stub_offset;
int _consts_offset;
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
// 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
nmFlags flags; // various flags to keep track of nmethod state
bool _markedForDeoptimization; // Used for stack deoptimization
enum { alive = 0,
not_entrant = 1, // uncommon trap has happened but activations may still exist
zombie = 2,
unloaded = 3 };
// used by jvmti to track if an unload event has been posted for this nmethod.
bool _unload_reported;
jbyte _scavenge_root_state;
NOT_PRODUCT(bool _has_debug_info; )
// Nmethod Flushing lock (if non-zero, then the nmethod is not removed)
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 only 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.
ByteSize _compiled_synchronized_native_basic_lock_owner_sp_offset;
ByteSize _compiled_synchronized_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 check that writes to nmFlags are done consistently.
static void check_safepoint() PRODUCT_RETURN;
// 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
inline void post_compiled_method_unload();
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 code_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;
// boundaries for different parts
address code_begin () const { return _entry_point; }
address code_end () const { return header_begin() + _stub_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; }
address stub_begin () const { return header_begin() + _stub_offset ; }
address stub_end () const { return header_begin() + _consts_offset ; }
address consts_begin () const { return header_begin() + _consts_offset ; }
address consts_end () const { return 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 ; }
int code_size () const { return code_end () - code_begin (); }
int stub_size () const { return stub_end () - stub_begin (); }
int consts_size () const { return consts_end () - consts_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;
bool code_contains (address addr) const { return code_begin () <= addr && addr < code_end (); }
bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); }
bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_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 flags.state == alive; }
bool is_alive() const { return flags.state == alive || flags.state == not_entrant; }
bool is_not_entrant() const { return flags.state == not_entrant; }
bool is_zombie() const { return flags.state == zombie; }
bool is_unloaded() const { return flags.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 _markedForDeoptimization; }
void mark_for_deoptimization() { _markedForDeoptimization = 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 flags.hasFlushedDependencies; }
void set_has_flushed_dependencies() {
check_safepoint();
assert(!has_flushed_dependencies(), "should only happen once");
flags.hasFlushedDependencies = 1;
}
bool is_marked_for_reclamation() const { return flags.markedForReclamation; }
void mark_for_reclamation() { check_safepoint(); flags.markedForReclamation = 1; }
void unmark_for_reclamation() { check_safepoint(); flags.markedForReclamation = 0; }
bool has_unsafe_access() const { return flags.has_unsafe_access; }
void set_has_unsafe_access(bool z) { flags.has_unsafe_access = z; }
bool has_method_handle_invokes() const { return flags.has_method_handle_invokes; }
void set_has_method_handle_invokes(bool z) { flags.has_method_handle_invokes = z; }
bool is_speculatively_disconnected() const { return flags.speculatively_disconnected; }
void set_speculatively_disconnected(bool z) { flags.speculatively_disconnected = z; }
int level() const { return flags.level; }
void set_level(int newLevel) { check_safepoint(); flags.level = newLevel; }
int comp_level() const { return _comp_level; }
int version() const { return flags.version; }
void set_version(int v);
// 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 >= instructions_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:
// If returning true, it is unsafe to remove this nmethod even though it is a zombie
// nmethod, since the VM might have a reference to it. Should only be called from a safepoint.
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);
virtual 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 - instructions_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();
// 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);
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 compiled_synchronized_native_basic_lock_owner_sp_offset() {
return _compiled_synchronized_native_basic_lock_owner_sp_offset;
}
ByteSize compiled_synchronized_native_basic_lock_sp_offset() {
return _compiled_synchronized_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, even if it is a zombie/not_entrant method
class nmethodLocker : public StackObj {
nmethod* _nm;
static void lock_nmethod(nmethod* nm); // note: nm can be NULL
static void unlock_nmethod(nmethod* nm); // (ditto)
public:
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);
}
};