8212996: Use AS_NO_KEEPALIVE when accessing dead java.lang.invoke.CallSites during nmethod unloading
Reviewed-by: coleenp, pliden
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#ifndef SHARE_VM_CODE_NMETHOD_HPP
#define SHARE_VM_CODE_NMETHOD_HPP
#include "code/compiledMethod.hpp"
class DepChange;
class DirectiveSet;
// nmethods (native methods) are the compiled code versions of Java methods.
//
// An nmethod contains:
// - header (the nmethod structure)
// [Relocation]
// - relocation information
// - constant part (doubles, longs and floats used in nmethod)
// - oop table
// [Code]
// - code body
// - exception handler
// - stub code
// [Debugging information]
// - oop array
// - data array
// - pcs
// [Exception handler table]
// - handler entry point array
// [Implicit Null Pointer exception table]
// - implicit null table array
class nmethod : public CompiledMethod {
friend class VMStructs;
friend class JVMCIVMStructs;
friend class NMethodSweeper;
friend class CodeCache; // scavengable oops
private:
// Shared fields for all nmethod's
int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
jmethodID _jmethod_id; // Cache of method()->jmethod_id()
#if INCLUDE_JVMCI
// A weak reference to an InstalledCode object associated with
// this nmethod.
jweak _jvmci_installed_code;
// A weak reference to a SpeculationLog object associated with
// this nmethod.
jweak _speculation_log;
// Determines whether this nmethod is unloaded when the
// referent in _jvmci_installed_code is cleared. This
// will be false if the referent is initialized to a
// HotSpotNMethod object whose isDefault field is true.
// That is, installed code other than a "default"
// HotSpotNMethod causes nmethod unloading.
// This field is ignored once _jvmci_installed_code is NULL.
bool _jvmci_installed_code_triggers_invalidation;
#endif
// To support simple linked-list chaining of nmethods:
nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
static nmethod* volatile _oops_do_mark_nmethods;
nmethod* volatile _oops_do_mark_link;
// 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;
// Offset of the unwind handler if it exists
int _unwind_handler_offset;
int _consts_offset;
int _stub_offset;
int _oops_offset; // offset to where embedded oop table begins (inside data)
int _metadata_offset; // embedded meta data table
int _scopes_data_offset;
int _scopes_pcs_offset;
int _dependencies_offset;
int _handler_table_offset;
int _nul_chk_table_offset;
int _nmethod_end_offset;
int code_offset() const { return (address) code_begin() - header_begin(); }
// 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)
// used by jvmti to track if an unload event has been posted for this nmethod.
bool _unload_reported;
// Protected by Patching_lock
volatile signed char _state; // {not_installed, in_use, not_entrant, zombie, unloaded}
#ifdef ASSERT
bool _oops_are_stale; // indicates that it's no longer safe to access oops section
#endif
jbyte _scavenge_root_state;
#if INCLUDE_RTM_OPT
// RTM state at compile time. Used during deoptimization to decide
// whether to restart collecting RTM locking abort statistic again.
RTMState _rtm_state;
#endif
// 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.
volatile 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 are no
// more activations, i.e., when the _stack_traversal_mark is less than
// current sweep traversal index.
volatile long _stack_traversal_mark;
// The _hotness_counter indicates the hotness of a method. The higher
// the value the hotter the method. The hotness counter of a nmethod is
// set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
// is active while stack scanning (mark_active_nmethods()). The hotness
// counter is decreased (by 1) while sweeping.
int _hotness_counter;
// 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(Method* method,
CompilerType type,
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);
// Creation support
nmethod(Method* method,
CompilerType type,
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
#if INCLUDE_JVMCI
, jweak installed_code,
jweak speculation_log
#endif
);
// helper methods
void* operator new(size_t size, int nmethod_size, int comp_level) throw();
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(int state);
bool make_entrant() { Unimplemented(); return false; }
void inc_decompile_count();
// Inform external interfaces that a compiled method has been unloaded
void post_compiled_method_unload();
// Initailize fields to their default values
void init_defaults();
// Offsets
int content_offset() const { return content_begin() - header_begin(); }
int data_offset() const { return _data_offset; }
address header_end() const { return (address) header_begin() + header_size(); }
public:
// create nmethod with entry_bci
static nmethod* new_nmethod(const 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
#if INCLUDE_JVMCI
, jweak installed_code = NULL,
jweak speculation_log = NULL
#endif
);
static nmethod* new_native_nmethod(const 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);
// type info
bool is_nmethod() const { return true; }
bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
// boundaries for different parts
address consts_begin () const { return header_begin() + _consts_offset ; }
address consts_end () const { return code_begin() ; }
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 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() + _metadata_offset) ; }
Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
Metadata** metadata_end () const { return (Metadata**) _scopes_data_begin; }
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 oops_size () const { return (address) oops_end () - (address) oops_begin (); }
int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
int oops_count() const { assert(oops_size() % oopSize == 0, ""); return (oops_size() / oopSize) + 1; }
int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
int total_size () const;
void dec_hotness_counter() { _hotness_counter--; }
void set_hotness_counter(int val) { _hotness_counter = val; }
int hotness_counter() const { return _hotness_counter; }
// Containment
bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_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 (); }
// 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_not_installed() const { return _state == not_installed; }
bool is_in_use() const { return _state <= in_use; }
bool is_alive() const { return _state < zombie; }
bool is_not_entrant() const { return _state == not_entrant; }
bool is_zombie() const { return _state == zombie; }
bool is_unloaded() const { return _state == unloaded; }
virtual void do_unloading(bool unloading_occurred);
#if INCLUDE_RTM_OPT
// rtm state accessing and manipulating
RTMState rtm_state() const { return _rtm_state; }
void set_rtm_state(RTMState state) { _rtm_state = state; }
#endif
void make_in_use() { _state = in_use; }
// 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() {
assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
return make_not_entrant_or_zombie(not_entrant);
}
bool make_not_used() { return make_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; }
int get_state() const {
return _state;
}
void make_unloaded();
bool has_dependencies() { return dependencies_size() != 0; }
void flush_dependencies(bool delete_immediately);
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;
}
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;
oop* oop_addr_at(int index) const { // for GC
// relocation indexes are biased by 1 (because 0 is reserved)
assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
assert(!_oops_are_stale, "oops are stale");
return &oops_begin()[index - 1];
}
// Support for meta data in scopes and relocs:
// Note: index 0 is reserved for null.
Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
Metadata** metadata_addr_at(int index) const { // for GC
// relocation indexes are biased by 1 (because 0 is reserved)
assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
return &metadata_begin()[index - 1];
}
void copy_values(GrowableArray<jobject>* oops);
void copy_values(GrowableArray<Metadata*>* metadata);
// 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); }
// 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; }
public:
// Sweeper support
long stack_traversal_mark() { return _stack_traversal_mark; }
void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
// 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; }
// Verify calls to dead methods have been cleaned.
void verify_clean_inline_caches();
// 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_convert_to_zombie();
// Evolution support. We make old (discarded) compiled methods point to new Method*s.
void set_method(Method* method) { _method = method; }
#if INCLUDE_JVMCI
// Gets the InstalledCode object associated with this nmethod
// which may be NULL if this nmethod was not compiled by JVMCI
// or the weak reference has been cleared.
oop jvmci_installed_code();
// Copies the value of the name field in the InstalledCode
// object (if any) associated with this nmethod into buf.
// Returns the value of buf if it was updated otherwise NULL.
char* jvmci_installed_code_name(char* buf, size_t buflen) const;
// Updates the state of the InstalledCode (if any) associated with
// this nmethod based on the current value of _state.
void maybe_invalidate_installed_code();
// Deoptimizes the nmethod (if any) in the address field of a given
// InstalledCode object. The address field is zeroed upon return.
static void invalidate_installed_code(Handle installed_code, TRAPS);
// Gets the SpeculationLog object associated with this nmethod
// which may be NULL if this nmethod was not compiled by JVMCI
// or the weak reference has been cleared.
oop speculation_log();
private:
// Deletes the weak reference (if any) to the InstalledCode object
// associated with this nmethod.
void clear_jvmci_installed_code();
// Deletes the weak reference (if any) to the SpeculationLog object
// associated with this nmethod.
void clear_speculation_log();
public:
#endif
public:
void oops_do(OopClosure* f) { oops_do(f, false); }
void oops_do(OopClosure* f, bool allow_zombie);
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; }
private:
ScopeDesc* scope_desc_in(address begin, address end);
address* orig_pc_addr(const frame* fr);
public:
// copying of debugging information
void copy_scopes_pcs(PcDesc* pcs, int count);
void copy_scopes_data(address buffer, int size);
// 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; }
// 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_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_recorded_oops() PRODUCT_RETURN;
void print_recorded_metadata() PRODUCT_RETURN;
void maybe_print_nmethod(DirectiveSet* directive);
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.
virtual int compile_id() const { return _compile_id; }
const char* compile_kind() const;
// tells if any of this method's dependencies have been invalidated
// (this is expensive!)
static void check_all_dependencies(DepChange& changes);
// 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(Klass* 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.
virtual bool is_dependent_on_method(Method* 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 state_offset() { return offset_of(nmethod, _state); }
virtual void metadata_do(void f(Metadata*));
NativeCallWrapper* call_wrapper_at(address call) const;
NativeCallWrapper* call_wrapper_before(address return_pc) const;
address call_instruction_address(address pc) const;
virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const;
virtual CompiledStaticCall* compiledStaticCall_at(address addr) const;
virtual CompiledStaticCall* compiledStaticCall_before(address addr) const;
};
// Locks an nmethod so its code will not get removed and it will not
// be made into a zombie, even if it is a not_entrant method. After the
// nmethod becomes a zombie, if CompiledMethodUnload event processing
// needs to be done, then lock_nmethod() is used directly to keep the
// generated code from being reused too early.
class nmethodLocker : public StackObj {
CompiledMethod* _nm;
public:
// note: nm can be NULL
// Only JvmtiDeferredEvent::compiled_method_unload_event()
// should pass zombie_ok == true.
static void lock_nmethod(CompiledMethod* nm, bool zombie_ok = false);
static void unlock_nmethod(CompiledMethod* nm); // (ditto)
nmethodLocker(address pc); // derive nm from pc
nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
nmethodLocker(CompiledMethod *nm) {
_nm = nm;
lock(_nm);
}
static void lock(CompiledMethod* method) {
if (method == NULL) return;
lock_nmethod(method);
}
static void unlock(CompiledMethod* method) {
if (method == NULL) return;
unlock_nmethod(method);
}
nmethodLocker() { _nm = NULL; }
~nmethodLocker() {
unlock(_nm);
}
CompiledMethod* code() { return _nm; }
void set_code(CompiledMethod* new_nm) {
unlock(_nm); // note: This works even if _nm==new_nm.
_nm = new_nm;
lock(_nm);
}
};
#endif // SHARE_VM_CODE_NMETHOD_HPP