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src/hotspot/share/oops/methodData.hpp

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  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_OOPS_METHODDATA_HPP
  26 #define SHARE_OOPS_METHODDATA_HPP
  27 
  28 #include "interpreter/bytecodes.hpp"
  29 #include "interpreter/invocationCounter.hpp"
  30 #include "oops/metadata.hpp"
  31 #include "oops/method.hpp"
  32 #include "oops/oop.hpp"
  33 #include "runtime/atomic.hpp"
  34 #include "runtime/deoptimization.hpp"
  35 #include "runtime/mutex.hpp"
  36 #include "utilities/align.hpp"
  37 #include "utilities/copy.hpp"
  38 
  39 class BytecodeStream;
  40 
  41 // The MethodData object collects counts and other profile information
  42 // during zeroth-tier (interpreter) and third-tier (C1 with full profiling)
  43 // execution.
  44 //
  45 // The profile is used later by compilation heuristics.  Some heuristics
  46 // enable use of aggressive (or "heroic") optimizations.  An aggressive
  47 // optimization often has a down-side, a corner case that it handles
  48 // poorly, but which is thought to be rare.  The profile provides
  49 // evidence of this rarity for a given method or even BCI.  It allows
  50 // the compiler to back out of the optimization at places where it
  51 // has historically been a poor choice.  Other heuristics try to use
  52 // specific information gathered about types observed at a given site.

 186     return Atomic::load_acquire(&_header._struct._flags);
 187   }
 188 
 189   u2 bci() const {
 190     return _header._struct._bci;
 191   }
 192 
 193   void set_header(u8 value) {
 194     _header._bits = value;
 195   }
 196   u8 header() {
 197     return _header._bits;
 198   }
 199   void set_cell_at(int index, intptr_t value) {
 200     _cells[index] = value;
 201   }
 202   void release_set_cell_at(int index, intptr_t value);
 203   intptr_t cell_at(int index) const {
 204     return _cells[index];
 205   }



 206 
 207   bool set_flag_at(u1 flag_number) {
 208     const u1 bit = 1 << flag_number;
 209     u1 compare_value;
 210     do {
 211       compare_value = _header._struct._flags;
 212       if ((compare_value & bit) == bit) {
 213         // already set.
 214         return false;
 215       }
 216     } while (compare_value != Atomic::cmpxchg(&_header._struct._flags, compare_value, static_cast<u1>(compare_value | bit)));
 217     return true;
 218   }
 219 
 220   bool clear_flag_at(u1 flag_number) {
 221     const u1 bit = 1 << flag_number;
 222     u1 compare_value;
 223     u1 exchange_value;
 224     do {
 225       compare_value = _header._struct._flags;

 329     ShouldNotReachHere();
 330     return -1;
 331   }
 332 
 333   // Return the size of this data.
 334   int size_in_bytes() {
 335     return DataLayout::compute_size_in_bytes(cell_count());
 336   }
 337 
 338 protected:
 339   // Low-level accessors for underlying data
 340   void set_intptr_at(int index, intptr_t value) {
 341     assert(0 <= index && index < cell_count(), "oob");
 342     data()->set_cell_at(index, value);
 343   }
 344   void release_set_intptr_at(int index, intptr_t value);
 345   intptr_t intptr_at(int index) const {
 346     assert(0 <= index && index < cell_count(), "oob");
 347     return data()->cell_at(index);
 348   }




 349   void set_uint_at(int index, uint value) {
 350     set_intptr_at(index, (intptr_t) value);
 351   }
 352   void release_set_uint_at(int index, uint value);
 353   uint uint_at(int index) const {
 354     return (uint)intptr_at(index);
 355   }
 356   void set_int_at(int index, int value) {
 357     set_intptr_at(index, (intptr_t) value);
 358   }
 359   void release_set_int_at(int index, int value);
 360   int int_at(int index) const {
 361     return (int)intptr_at(index);
 362   }
 363   int int_at_unchecked(int index) const {
 364     return (int)data()->cell_at(index);
 365   }
 366   void set_oop_at(int index, oop value) {
 367     set_intptr_at(index, cast_from_oop<intptr_t>(value));
 368   }
 369   oop oop_at(int index) const {
 370     return cast_to_oop(intptr_at(index));
 371   }
 372 
 373   void set_flag_at(u1 flag_number) {
 374     data()->set_flag_at(flag_number);
 375   }
 376   bool flag_at(u1 flag_number) const {
 377     return data()->flag_at(flag_number);
 378   }
 379 
 380   // two convenient imports for use by subclasses:
 381   static ByteSize cell_offset(int index) {
 382     return DataLayout::cell_offset(index);
 383   }
 384   static u1 flag_number_to_constant(u1 flag_number) {
 385     return DataLayout::flag_number_to_constant(flag_number);
 386   }
 387 
 388   ProfileData(DataLayout* data) {
 389     _data = data;
 390   }
 391 

 472   VirtualCallTypeData* as_VirtualCallTypeData() const {
 473     assert(is_VirtualCallTypeData(), "wrong type");
 474     return is_VirtualCallTypeData() ? (VirtualCallTypeData*)this : nullptr;
 475   }
 476   ParametersTypeData* as_ParametersTypeData() const {
 477     assert(is_ParametersTypeData(), "wrong type");
 478     return is_ParametersTypeData() ? (ParametersTypeData*)this : nullptr;
 479   }
 480   SpeculativeTrapData* as_SpeculativeTrapData() const {
 481     assert(is_SpeculativeTrapData(), "wrong type");
 482     return is_SpeculativeTrapData() ? (SpeculativeTrapData*)this : nullptr;
 483   }
 484 
 485 
 486   // Subclass specific initialization
 487   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo) {}
 488 
 489   // GC support
 490   virtual void clean_weak_klass_links(bool always_clean) {}
 491 
 492   // CI translation: ProfileData can represent both MethodDataOop data



 493   // as well as CIMethodData data. This function is provided for translating
 494   // an oop in a ProfileData to the ci equivalent. Generally speaking,
 495   // most ProfileData don't require any translation, so we provide the null
 496   // translation here, and the required translators are in the ci subclasses.
 497   virtual void translate_from(const ProfileData* data) {}
 498 
 499   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const {
 500     ShouldNotReachHere();
 501   }
 502 
 503   void print_data_on(outputStream* st, const MethodData* md) const;
 504 
 505   void print_shared(outputStream* st, const char* name, const char* extra) const;
 506   void tab(outputStream* st, bool first = false) const;
 507 };
 508 
 509 // BitData
 510 //
 511 // A BitData holds a flag or two in its header.
 512 class BitData : public ProfileData {

 837   }
 838 
 839   // stack slot for entry i
 840   uint stack_slot(int i) const {
 841     assert(i >= 0 && i < _number_of_entries, "oob");
 842     return _pd->uint_at(stack_slot_offset(i));
 843   }
 844 
 845   // set stack slot for entry i
 846   void set_stack_slot(int i, uint num) {
 847     assert(i >= 0 && i < _number_of_entries, "oob");
 848     _pd->set_uint_at(stack_slot_offset(i), num);
 849   }
 850 
 851   // type for entry i
 852   intptr_t type(int i) const {
 853     assert(i >= 0 && i < _number_of_entries, "oob");
 854     return _pd->intptr_at(type_offset_in_cells(i));
 855   }
 856 





 857   // set type for entry i
 858   void set_type(int i, intptr_t k) {
 859     assert(i >= 0 && i < _number_of_entries, "oob");
 860     _pd->set_intptr_at(type_offset_in_cells(i), k);
 861   }
 862 
 863   static ByteSize per_arg_size() {
 864     return in_ByteSize(per_arg_cell_count * DataLayout::cell_size);
 865   }
 866 
 867   static int per_arg_count() {
 868     return per_arg_cell_count;
 869   }
 870 
 871   ByteSize type_offset(int i) const {
 872     return DataLayout::cell_offset(type_offset_in_cells(i));
 873   }
 874 
 875   // GC support
 876   void clean_weak_klass_links(bool always_clean);
 877 



 878   void print_data_on(outputStream* st) const;
 879 };
 880 
 881 // Type entry used for return from a call. A single cell to record the
 882 // type.
 883 class ReturnTypeEntry : public TypeEntries {
 884 
 885 private:
 886   enum {
 887     cell_count = 1
 888   };
 889 
 890 public:
 891   ReturnTypeEntry(int base_off)
 892     : TypeEntries(base_off) {}
 893 
 894   void post_initialize() {
 895     set_type(type_none());
 896   }
 897 
 898   intptr_t type() const {
 899     return _pd->intptr_at(_base_off);
 900   }
 901 




 902   void set_type(intptr_t k) {
 903     _pd->set_intptr_at(_base_off, k);
 904   }
 905 
 906   static int static_cell_count() {
 907     return cell_count;
 908   }
 909 
 910   static ByteSize size() {
 911     return in_ByteSize(cell_count * DataLayout::cell_size);
 912   }
 913 
 914   ByteSize type_offset() {
 915     return DataLayout::cell_offset(_base_off);
 916   }
 917 
 918   // GC support
 919   void clean_weak_klass_links(bool always_clean);
 920 



 921   void print_data_on(outputStream* st) const;
 922 };
 923 
 924 // Entries to collect type information at a call: contains arguments
 925 // (TypeStackSlotEntries), a return type (ReturnTypeEntry) and a
 926 // number of cells. Because the number of cells for the return type is
 927 // smaller than the number of cells for the type of an arguments, the
 928 // number of cells is used to tell how many arguments are profiled and
 929 // whether a return value is profiled. See has_arguments() and
 930 // has_return().
 931 class TypeEntriesAtCall {
 932 private:
 933   static int stack_slot_local_offset(int i) {
 934     return header_cell_count() + TypeStackSlotEntries::stack_slot_local_offset(i);
 935   }
 936 
 937   static int argument_type_local_offset(int i) {
 938     return header_cell_count() + TypeStackSlotEntries::type_local_offset(i);
 939   }
 940 

1092   }
1093 
1094   ByteSize argument_type_offset(int i) {
1095     return _args.type_offset(i);
1096   }
1097 
1098   ByteSize return_type_offset() {
1099     return _ret.type_offset();
1100   }
1101 
1102   // GC support
1103   virtual void clean_weak_klass_links(bool always_clean) {
1104     if (has_arguments()) {
1105       _args.clean_weak_klass_links(always_clean);
1106     }
1107     if (has_return()) {
1108       _ret.clean_weak_klass_links(always_clean);
1109     }
1110   }
1111 










1112   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1113 };
1114 
1115 // ReceiverTypeData
1116 //
1117 // A ReceiverTypeData is used to access profiling information about a
1118 // dynamic type check.  It consists of a series of (Klass*, count)
1119 // pairs which are used to store a type profile for the receiver of
1120 // the check, the associated count is incremented every time the type
1121 // is seen. A per ReceiverTypeData counter is incremented on type
1122 // overflow (when there's no more room for a not yet profiled Klass*).
1123 //
1124 class ReceiverTypeData : public CounterData {
1125   friend class VMStructs;
1126   friend class JVMCIVMStructs;
1127 protected:
1128   enum {
1129     receiver0_offset = counter_cell_count,
1130     count0_offset,
1131     receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset

1202     //
1203     set_count(0);
1204     set_receiver(row, nullptr);
1205     set_receiver_count(row, 0);
1206   }
1207 
1208   // Code generation support
1209   static ByteSize receiver_offset(uint row) {
1210     return cell_offset(receiver_cell_index(row));
1211   }
1212   static ByteSize receiver_count_offset(uint row) {
1213     return cell_offset(receiver_count_cell_index(row));
1214   }
1215   static ByteSize receiver_type_data_size() {
1216     return cell_offset(static_cell_count());
1217   }
1218 
1219   // GC support
1220   virtual void clean_weak_klass_links(bool always_clean);
1221 



1222   void print_receiver_data_on(outputStream* st) const;
1223   void print_data_on(outputStream* st, const char* extra = nullptr) const;
1224 };
1225 
1226 // VirtualCallData
1227 //
1228 // A VirtualCallData is used to access profiling information about a
1229 // virtual call.  For now, it has nothing more than a ReceiverTypeData.
1230 class VirtualCallData : public ReceiverTypeData {
1231 public:
1232   VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
1233     assert(layout->tag() == DataLayout::virtual_call_data_tag ||
1234            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1235   }
1236 
1237   virtual bool is_VirtualCallData() const { return true; }
1238 
1239   static int static_cell_count() {
1240     // At this point we could add more profile state, e.g., for arguments.
1241     // But for now it's the same size as the base record type.

1367 
1368   ByteSize argument_type_offset(int i) {
1369     return _args.type_offset(i);
1370   }
1371 
1372   ByteSize return_type_offset() {
1373     return _ret.type_offset();
1374   }
1375 
1376   // GC support
1377   virtual void clean_weak_klass_links(bool always_clean) {
1378     ReceiverTypeData::clean_weak_klass_links(always_clean);
1379     if (has_arguments()) {
1380       _args.clean_weak_klass_links(always_clean);
1381     }
1382     if (has_return()) {
1383       _ret.clean_weak_klass_links(always_clean);
1384     }
1385   }
1386 











1387   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1388 };
1389 
1390 // RetData
1391 //
1392 // A RetData is used to access profiling information for a ret bytecode.
1393 // It is composed of a count of the number of times that the ret has
1394 // been executed, followed by a series of triples of the form
1395 // (bci, count, di) which count the number of times that some bci was the
1396 // target of the ret and cache a corresponding data displacement.
1397 class RetData : public CounterData {
1398 protected:
1399   enum {
1400     bci0_offset = counter_cell_count,
1401     count0_offset,
1402     displacement0_offset,
1403     ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
1404   };
1405 
1406   void set_bci(uint row, int bci) {

1550 // and an array start.
1551 class ArrayData : public ProfileData {
1552   friend class VMStructs;
1553   friend class JVMCIVMStructs;
1554 protected:
1555   friend class DataLayout;
1556 
1557   enum {
1558     array_len_off_set,
1559     array_start_off_set
1560   };
1561 
1562   uint array_uint_at(int index) const {
1563     int aindex = index + array_start_off_set;
1564     return uint_at(aindex);
1565   }
1566   int array_int_at(int index) const {
1567     int aindex = index + array_start_off_set;
1568     return int_at(aindex);
1569   }
1570   oop array_oop_at(int index) const {
1571     int aindex = index + array_start_off_set;
1572     return oop_at(aindex);
1573   }
1574   void array_set_int_at(int index, int value) {
1575     int aindex = index + array_start_off_set;
1576     set_int_at(aindex, value);
1577   }
1578 
1579   // Code generation support for subclasses.
1580   static ByteSize array_element_offset(int index) {
1581     return cell_offset(array_start_off_set + index);
1582   }
1583 
1584 public:
1585   ArrayData(DataLayout* layout) : ProfileData(layout) {}
1586 
1587   virtual bool is_ArrayData() const { return true; }
1588 
1589   static int static_cell_count() {
1590     return -1;
1591   }
1592 
1593   int array_len() const {

1766 
1767   int number_of_parameters() const {
1768     return array_len() / TypeStackSlotEntries::per_arg_count();
1769   }
1770 
1771   const TypeStackSlotEntries* parameters() const { return &_parameters; }
1772 
1773   uint stack_slot(int i) const {
1774     return _parameters.stack_slot(i);
1775   }
1776 
1777   void set_type(int i, Klass* k) {
1778     intptr_t current = _parameters.type(i);
1779     _parameters.set_type(i, TypeEntries::with_status((intptr_t)k, current));
1780   }
1781 
1782   virtual void clean_weak_klass_links(bool always_clean) {
1783     _parameters.clean_weak_klass_links(always_clean);
1784   }
1785 





1786   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1787 
1788   static ByteSize stack_slot_offset(int i) {
1789     return cell_offset(stack_slot_local_offset(i));
1790   }
1791 
1792   static ByteSize type_offset(int i) {
1793     return cell_offset(type_local_offset(i));
1794   }
1795 };
1796 
1797 // SpeculativeTrapData
1798 //
1799 // A SpeculativeTrapData is used to record traps due to type
1800 // speculation. It records the root of the compilation: that type
1801 // speculation is wrong in the context of one compilation (for
1802 // method1) doesn't mean it's wrong in the context of another one (for
1803 // method2). Type speculation could have more/different data in the
1804 // context of the compilation of method2 and it's worthwhile to try an
1805 // optimization that failed for compilation of method1 in the context

1836   }
1837 
1838   virtual int cell_count() const {
1839     return static_cell_count();
1840   }
1841 
1842   // Direct accessor
1843   Method* method() const {
1844     return (Method*)intptr_at(speculative_trap_method);
1845   }
1846 
1847   void set_method(Method* m) {
1848     assert(!m->is_old(), "cannot add old methods");
1849     set_intptr_at(speculative_trap_method, (intptr_t)m);
1850   }
1851 
1852   static ByteSize method_offset() {
1853     return cell_offset(speculative_trap_method);
1854   }
1855 



1856   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1857 };
1858 
1859 // MethodData*
1860 //
1861 // A MethodData* holds information which has been collected about
1862 // a method.  Its layout looks like this:
1863 //
1864 // -----------------------------
1865 // | header                    |
1866 // | klass                     |
1867 // -----------------------------
1868 // | method                    |
1869 // | size of the MethodData* |
1870 // -----------------------------
1871 // | Data entries...           |
1872 // |   (variable size)         |
1873 // |                           |
1874 // .                           .
1875 // .                           .

1946 class MethodData : public Metadata {
1947   friend class VMStructs;
1948   friend class JVMCIVMStructs;
1949 private:
1950   friend class ProfileData;
1951   friend class TypeEntriesAtCall;
1952   friend class ciMethodData;
1953 
1954   // If you add a new field that points to any metaspace object, you
1955   // must add this field to MethodData::metaspace_pointers_do().
1956 
1957   // Back pointer to the Method*
1958   Method* _method;
1959 
1960   // Size of this oop in bytes
1961   int _size;
1962 
1963   // Cached hint for bci_to_dp and bci_to_data
1964   int _hint_di;
1965 
1966   Mutex _extra_data_lock;
1967 
1968   MethodData(const methodHandle& method);
1969 public:


1970   static MethodData* allocate(ClassLoaderData* loader_data, const methodHandle& method, TRAPS);
1971 
1972   virtual bool is_methodData() const { return true; }
1973   void initialize();
1974 
1975   // Whole-method sticky bits and flags
1976   enum {
1977     _trap_hist_limit    = Deoptimization::Reason_TRAP_HISTORY_LENGTH,
1978     _trap_hist_mask     = max_jubyte,
1979     _extra_data_count   = 4     // extra DataLayout headers, for trap history
1980   }; // Public flag values
1981 
1982   // Compiler-related counters.
1983   class CompilerCounters {
1984     friend class VMStructs;
1985     friend class JVMCIVMStructs;
1986 
1987     uint _nof_decompiles;             // count of all nmethod removals
1988     uint _nof_overflow_recompiles;    // recompile count, excluding recomp. bits
1989     uint _nof_overflow_traps;         // trap count, excluding _trap_hist

1990     union {
1991       intptr_t _align;
1992       // JVMCI separates trap history for OSR compilations from normal compilations
1993       u1 _array[JVMCI_ONLY(2 *) MethodData::_trap_hist_limit];
1994     } _trap_hist;
1995 
1996   public:
1997     CompilerCounters() : _nof_decompiles(0), _nof_overflow_recompiles(0), _nof_overflow_traps(0) {
1998 #ifndef ZERO
1999       // Some Zero platforms do not have expected alignment, and do not use
2000       // this code. static_assert would still fire and fail for them.
2001       static_assert(sizeof(_trap_hist) % HeapWordSize == 0, "align");
2002 #endif
2003       uint size_in_words = sizeof(_trap_hist) / HeapWordSize;
2004       Copy::zero_to_words((HeapWord*) &_trap_hist, size_in_words);
2005     }
2006 
2007     // Return (uint)-1 for overflow.
2008     uint trap_count(int reason) const {
2009       assert((uint)reason < ARRAY_SIZE(_trap_hist._array), "oob");
2010       return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
2011     }
2012 
2013     uint inc_trap_count(int reason) {
2014       // Count another trap, anywhere in this method.
2015       assert(reason >= 0, "must be single trap");
2016       assert((uint)reason < ARRAY_SIZE(_trap_hist._array), "oob");
2017       uint cnt1 = 1 + _trap_hist._array[reason];

2269     return &_failed_speculations;
2270   }
2271 #endif
2272 
2273 #if INCLUDE_RTM_OPT
2274   int rtm_state() const {
2275     return _rtm_state;
2276   }
2277   void set_rtm_state(RTMState rstate) {
2278     _rtm_state = (int)rstate;
2279   }
2280   void atomic_set_rtm_state(RTMState rstate) {
2281     Atomic::store(&_rtm_state, (int)rstate);
2282   }
2283 
2284   static ByteSize rtm_state_offset() {
2285     return byte_offset_of(MethodData, _rtm_state);
2286   }
2287 #endif
2288 





2289   void set_would_profile(bool p)              { _would_profile = p ? profile : no_profile; }
2290   bool would_profile() const                  { return _would_profile != no_profile; }
2291 
2292   int num_loops() const                       { return _num_loops;  }
2293   void set_num_loops(short n)                 { _num_loops = n;     }
2294   int num_blocks() const                      { return _num_blocks; }
2295   void set_num_blocks(short n)                { _num_blocks = n;    }
2296 
2297   bool is_mature() const;  // consult mileage and ProfileMaturityPercentage
2298   static int mileage_of(Method* m);
2299 
2300   // Support for interprocedural escape analysis, from Thomas Kotzmann.
2301   enum EscapeFlag {
2302     estimated    = 1 << 0,
2303     return_local = 1 << 1,
2304     return_allocated = 1 << 2,
2305     allocated_escapes = 1 << 3,
2306     unknown_modified = 1 << 4
2307   };
2308 

2508   void print_value_on(outputStream* st) const;
2509 
2510   // printing support for method data
2511   void print_data_on(outputStream* st) const;
2512 
2513   const char* internal_name() const { return "{method data}"; }
2514 
2515   // verification
2516   void verify_on(outputStream* st);
2517   void verify_data_on(outputStream* st);
2518 
2519   static bool profile_parameters_for_method(const methodHandle& m);
2520   static bool profile_arguments();
2521   static bool profile_arguments_jsr292_only();
2522   static bool profile_return();
2523   static bool profile_parameters();
2524   static bool profile_return_jsr292_only();
2525 
2526   void clean_method_data(bool always_clean);
2527   void clean_weak_method_links();
2528   Mutex* extra_data_lock() { return &_extra_data_lock; }
2529   void check_extra_data_locked() const NOT_DEBUG_RETURN;
2530 };
2531 
2532 #endif // SHARE_OOPS_METHODDATA_HPP

  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_OOPS_METHODDATA_HPP
  26 #define SHARE_OOPS_METHODDATA_HPP
  27 
  28 #include "interpreter/bytecodes.hpp"
  29 #include "interpreter/invocationCounter.hpp"
  30 #include "oops/metadata.hpp"
  31 #include "oops/method.hpp"

  32 #include "runtime/atomic.hpp"
  33 #include "runtime/deoptimization.hpp"
  34 #include "runtime/mutex.hpp"
  35 #include "utilities/align.hpp"
  36 #include "utilities/copy.hpp"
  37 
  38 class BytecodeStream;
  39 
  40 // The MethodData object collects counts and other profile information
  41 // during zeroth-tier (interpreter) and third-tier (C1 with full profiling)
  42 // execution.
  43 //
  44 // The profile is used later by compilation heuristics.  Some heuristics
  45 // enable use of aggressive (or "heroic") optimizations.  An aggressive
  46 // optimization often has a down-side, a corner case that it handles
  47 // poorly, but which is thought to be rare.  The profile provides
  48 // evidence of this rarity for a given method or even BCI.  It allows
  49 // the compiler to back out of the optimization at places where it
  50 // has historically been a poor choice.  Other heuristics try to use
  51 // specific information gathered about types observed at a given site.

 185     return Atomic::load_acquire(&_header._struct._flags);
 186   }
 187 
 188   u2 bci() const {
 189     return _header._struct._bci;
 190   }
 191 
 192   void set_header(u8 value) {
 193     _header._bits = value;
 194   }
 195   u8 header() {
 196     return _header._bits;
 197   }
 198   void set_cell_at(int index, intptr_t value) {
 199     _cells[index] = value;
 200   }
 201   void release_set_cell_at(int index, intptr_t value);
 202   intptr_t cell_at(int index) const {
 203     return _cells[index];
 204   }
 205   intptr_t* cell_at_adr(int index) const {
 206     return const_cast<intptr_t*>(&_cells[index]);
 207   }
 208 
 209   bool set_flag_at(u1 flag_number) {
 210     const u1 bit = 1 << flag_number;
 211     u1 compare_value;
 212     do {
 213       compare_value = _header._struct._flags;
 214       if ((compare_value & bit) == bit) {
 215         // already set.
 216         return false;
 217       }
 218     } while (compare_value != Atomic::cmpxchg(&_header._struct._flags, compare_value, static_cast<u1>(compare_value | bit)));
 219     return true;
 220   }
 221 
 222   bool clear_flag_at(u1 flag_number) {
 223     const u1 bit = 1 << flag_number;
 224     u1 compare_value;
 225     u1 exchange_value;
 226     do {
 227       compare_value = _header._struct._flags;

 331     ShouldNotReachHere();
 332     return -1;
 333   }
 334 
 335   // Return the size of this data.
 336   int size_in_bytes() {
 337     return DataLayout::compute_size_in_bytes(cell_count());
 338   }
 339 
 340 protected:
 341   // Low-level accessors for underlying data
 342   void set_intptr_at(int index, intptr_t value) {
 343     assert(0 <= index && index < cell_count(), "oob");
 344     data()->set_cell_at(index, value);
 345   }
 346   void release_set_intptr_at(int index, intptr_t value);
 347   intptr_t intptr_at(int index) const {
 348     assert(0 <= index && index < cell_count(), "oob");
 349     return data()->cell_at(index);
 350   }
 351   intptr_t* intptr_at_adr(int index) const {
 352     assert(0 <= index && index < cell_count(), "oob");
 353     return data()->cell_at_adr(index);
 354   }
 355   void set_uint_at(int index, uint value) {
 356     set_intptr_at(index, (intptr_t) value);
 357   }
 358   void release_set_uint_at(int index, uint value);
 359   uint uint_at(int index) const {
 360     return (uint)intptr_at(index);
 361   }
 362   void set_int_at(int index, int value) {
 363     set_intptr_at(index, (intptr_t) value);
 364   }
 365   void release_set_int_at(int index, int value);
 366   int int_at(int index) const {
 367     return (int)intptr_at(index);
 368   }
 369   int int_at_unchecked(int index) const {
 370     return (int)data()->cell_at(index);
 371   }






 372 
 373   void set_flag_at(u1 flag_number) {
 374     data()->set_flag_at(flag_number);
 375   }
 376   bool flag_at(u1 flag_number) const {
 377     return data()->flag_at(flag_number);
 378   }
 379 
 380   // two convenient imports for use by subclasses:
 381   static ByteSize cell_offset(int index) {
 382     return DataLayout::cell_offset(index);
 383   }
 384   static u1 flag_number_to_constant(u1 flag_number) {
 385     return DataLayout::flag_number_to_constant(flag_number);
 386   }
 387 
 388   ProfileData(DataLayout* data) {
 389     _data = data;
 390   }
 391 

 472   VirtualCallTypeData* as_VirtualCallTypeData() const {
 473     assert(is_VirtualCallTypeData(), "wrong type");
 474     return is_VirtualCallTypeData() ? (VirtualCallTypeData*)this : nullptr;
 475   }
 476   ParametersTypeData* as_ParametersTypeData() const {
 477     assert(is_ParametersTypeData(), "wrong type");
 478     return is_ParametersTypeData() ? (ParametersTypeData*)this : nullptr;
 479   }
 480   SpeculativeTrapData* as_SpeculativeTrapData() const {
 481     assert(is_SpeculativeTrapData(), "wrong type");
 482     return is_SpeculativeTrapData() ? (SpeculativeTrapData*)this : nullptr;
 483   }
 484 
 485 
 486   // Subclass specific initialization
 487   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo) {}
 488 
 489   // GC support
 490   virtual void clean_weak_klass_links(bool always_clean) {}
 491 
 492   // CDS support
 493   virtual void metaspace_pointers_do(MetaspaceClosure* it) {}
 494 
 495     // CI translation: ProfileData can represent both MethodDataOop data
 496   // as well as CIMethodData data. This function is provided for translating
 497   // an oop in a ProfileData to the ci equivalent. Generally speaking,
 498   // most ProfileData don't require any translation, so we provide the null
 499   // translation here, and the required translators are in the ci subclasses.
 500   virtual void translate_from(const ProfileData* data) {}
 501 
 502   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const {
 503     ShouldNotReachHere();
 504   }
 505 
 506   void print_data_on(outputStream* st, const MethodData* md) const;
 507 
 508   void print_shared(outputStream* st, const char* name, const char* extra) const;
 509   void tab(outputStream* st, bool first = false) const;
 510 };
 511 
 512 // BitData
 513 //
 514 // A BitData holds a flag or two in its header.
 515 class BitData : public ProfileData {

 840   }
 841 
 842   // stack slot for entry i
 843   uint stack_slot(int i) const {
 844     assert(i >= 0 && i < _number_of_entries, "oob");
 845     return _pd->uint_at(stack_slot_offset(i));
 846   }
 847 
 848   // set stack slot for entry i
 849   void set_stack_slot(int i, uint num) {
 850     assert(i >= 0 && i < _number_of_entries, "oob");
 851     _pd->set_uint_at(stack_slot_offset(i), num);
 852   }
 853 
 854   // type for entry i
 855   intptr_t type(int i) const {
 856     assert(i >= 0 && i < _number_of_entries, "oob");
 857     return _pd->intptr_at(type_offset_in_cells(i));
 858   }
 859 
 860   intptr_t* type_adr(int i) const {
 861     assert(i >= 0 && i < _number_of_entries, "oob");
 862     return _pd->intptr_at_adr(type_offset_in_cells(i));
 863   }
 864 
 865   // set type for entry i
 866   void set_type(int i, intptr_t k) {
 867     assert(i >= 0 && i < _number_of_entries, "oob");
 868     _pd->set_intptr_at(type_offset_in_cells(i), k);
 869   }
 870 
 871   static ByteSize per_arg_size() {
 872     return in_ByteSize(per_arg_cell_count * DataLayout::cell_size);
 873   }
 874 
 875   static int per_arg_count() {
 876     return per_arg_cell_count;
 877   }
 878 
 879   ByteSize type_offset(int i) const {
 880     return DataLayout::cell_offset(type_offset_in_cells(i));
 881   }
 882 
 883   // GC support
 884   void clean_weak_klass_links(bool always_clean);
 885 
 886   // CDS support
 887   virtual void metaspace_pointers_do(MetaspaceClosure* it);
 888 
 889   void print_data_on(outputStream* st) const;
 890 };
 891 
 892 // Type entry used for return from a call. A single cell to record the
 893 // type.
 894 class ReturnTypeEntry : public TypeEntries {
 895 
 896 private:
 897   enum {
 898     cell_count = 1
 899   };
 900 
 901 public:
 902   ReturnTypeEntry(int base_off)
 903     : TypeEntries(base_off) {}
 904 
 905   void post_initialize() {
 906     set_type(type_none());
 907   }
 908 
 909   intptr_t type() const {
 910     return _pd->intptr_at(_base_off);
 911   }
 912 
 913   intptr_t* type_adr() const {
 914     return _pd->intptr_at_adr(_base_off);
 915   }
 916 
 917   void set_type(intptr_t k) {
 918     _pd->set_intptr_at(_base_off, k);
 919   }
 920 
 921   static int static_cell_count() {
 922     return cell_count;
 923   }
 924 
 925   static ByteSize size() {
 926     return in_ByteSize(cell_count * DataLayout::cell_size);
 927   }
 928 
 929   ByteSize type_offset() {
 930     return DataLayout::cell_offset(_base_off);
 931   }
 932 
 933   // GC support
 934   void clean_weak_klass_links(bool always_clean);
 935 
 936   // CDS support
 937   virtual void metaspace_pointers_do(MetaspaceClosure* it);
 938 
 939   void print_data_on(outputStream* st) const;
 940 };
 941 
 942 // Entries to collect type information at a call: contains arguments
 943 // (TypeStackSlotEntries), a return type (ReturnTypeEntry) and a
 944 // number of cells. Because the number of cells for the return type is
 945 // smaller than the number of cells for the type of an arguments, the
 946 // number of cells is used to tell how many arguments are profiled and
 947 // whether a return value is profiled. See has_arguments() and
 948 // has_return().
 949 class TypeEntriesAtCall {
 950 private:
 951   static int stack_slot_local_offset(int i) {
 952     return header_cell_count() + TypeStackSlotEntries::stack_slot_local_offset(i);
 953   }
 954 
 955   static int argument_type_local_offset(int i) {
 956     return header_cell_count() + TypeStackSlotEntries::type_local_offset(i);
 957   }
 958 

1110   }
1111 
1112   ByteSize argument_type_offset(int i) {
1113     return _args.type_offset(i);
1114   }
1115 
1116   ByteSize return_type_offset() {
1117     return _ret.type_offset();
1118   }
1119 
1120   // GC support
1121   virtual void clean_weak_klass_links(bool always_clean) {
1122     if (has_arguments()) {
1123       _args.clean_weak_klass_links(always_clean);
1124     }
1125     if (has_return()) {
1126       _ret.clean_weak_klass_links(always_clean);
1127     }
1128   }
1129 
1130   // CDS support
1131   virtual void metaspace_pointers_do(MetaspaceClosure* it) {
1132     if (has_arguments()) {
1133       _args.metaspace_pointers_do(it);
1134     }
1135     if (has_return()) {
1136       _ret.metaspace_pointers_do(it);
1137     }
1138   }
1139 
1140   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1141 };
1142 
1143 // ReceiverTypeData
1144 //
1145 // A ReceiverTypeData is used to access profiling information about a
1146 // dynamic type check.  It consists of a series of (Klass*, count)
1147 // pairs which are used to store a type profile for the receiver of
1148 // the check, the associated count is incremented every time the type
1149 // is seen. A per ReceiverTypeData counter is incremented on type
1150 // overflow (when there's no more room for a not yet profiled Klass*).
1151 //
1152 class ReceiverTypeData : public CounterData {
1153   friend class VMStructs;
1154   friend class JVMCIVMStructs;
1155 protected:
1156   enum {
1157     receiver0_offset = counter_cell_count,
1158     count0_offset,
1159     receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset

1230     //
1231     set_count(0);
1232     set_receiver(row, nullptr);
1233     set_receiver_count(row, 0);
1234   }
1235 
1236   // Code generation support
1237   static ByteSize receiver_offset(uint row) {
1238     return cell_offset(receiver_cell_index(row));
1239   }
1240   static ByteSize receiver_count_offset(uint row) {
1241     return cell_offset(receiver_count_cell_index(row));
1242   }
1243   static ByteSize receiver_type_data_size() {
1244     return cell_offset(static_cell_count());
1245   }
1246 
1247   // GC support
1248   virtual void clean_weak_klass_links(bool always_clean);
1249 
1250   // CDS support
1251   virtual void metaspace_pointers_do(MetaspaceClosure* it);
1252 
1253   void print_receiver_data_on(outputStream* st) const;
1254   void print_data_on(outputStream* st, const char* extra = nullptr) const;
1255 };
1256 
1257 // VirtualCallData
1258 //
1259 // A VirtualCallData is used to access profiling information about a
1260 // virtual call.  For now, it has nothing more than a ReceiverTypeData.
1261 class VirtualCallData : public ReceiverTypeData {
1262 public:
1263   VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
1264     assert(layout->tag() == DataLayout::virtual_call_data_tag ||
1265            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1266   }
1267 
1268   virtual bool is_VirtualCallData() const { return true; }
1269 
1270   static int static_cell_count() {
1271     // At this point we could add more profile state, e.g., for arguments.
1272     // But for now it's the same size as the base record type.

1398 
1399   ByteSize argument_type_offset(int i) {
1400     return _args.type_offset(i);
1401   }
1402 
1403   ByteSize return_type_offset() {
1404     return _ret.type_offset();
1405   }
1406 
1407   // GC support
1408   virtual void clean_weak_klass_links(bool always_clean) {
1409     ReceiverTypeData::clean_weak_klass_links(always_clean);
1410     if (has_arguments()) {
1411       _args.clean_weak_klass_links(always_clean);
1412     }
1413     if (has_return()) {
1414       _ret.clean_weak_klass_links(always_clean);
1415     }
1416   }
1417 
1418   // CDS support
1419   virtual void metaspace_pointers_do(MetaspaceClosure* it) {
1420     ReceiverTypeData::metaspace_pointers_do(it);
1421     if (has_arguments()) {
1422       _args.metaspace_pointers_do(it);
1423     }
1424     if (has_return()) {
1425       _ret.metaspace_pointers_do(it);
1426     }
1427   }
1428 
1429   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1430 };
1431 
1432 // RetData
1433 //
1434 // A RetData is used to access profiling information for a ret bytecode.
1435 // It is composed of a count of the number of times that the ret has
1436 // been executed, followed by a series of triples of the form
1437 // (bci, count, di) which count the number of times that some bci was the
1438 // target of the ret and cache a corresponding data displacement.
1439 class RetData : public CounterData {
1440 protected:
1441   enum {
1442     bci0_offset = counter_cell_count,
1443     count0_offset,
1444     displacement0_offset,
1445     ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
1446   };
1447 
1448   void set_bci(uint row, int bci) {

1592 // and an array start.
1593 class ArrayData : public ProfileData {
1594   friend class VMStructs;
1595   friend class JVMCIVMStructs;
1596 protected:
1597   friend class DataLayout;
1598 
1599   enum {
1600     array_len_off_set,
1601     array_start_off_set
1602   };
1603 
1604   uint array_uint_at(int index) const {
1605     int aindex = index + array_start_off_set;
1606     return uint_at(aindex);
1607   }
1608   int array_int_at(int index) const {
1609     int aindex = index + array_start_off_set;
1610     return int_at(aindex);
1611   }




1612   void array_set_int_at(int index, int value) {
1613     int aindex = index + array_start_off_set;
1614     set_int_at(aindex, value);
1615   }
1616 
1617   // Code generation support for subclasses.
1618   static ByteSize array_element_offset(int index) {
1619     return cell_offset(array_start_off_set + index);
1620   }
1621 
1622 public:
1623   ArrayData(DataLayout* layout) : ProfileData(layout) {}
1624 
1625   virtual bool is_ArrayData() const { return true; }
1626 
1627   static int static_cell_count() {
1628     return -1;
1629   }
1630 
1631   int array_len() const {

1804 
1805   int number_of_parameters() const {
1806     return array_len() / TypeStackSlotEntries::per_arg_count();
1807   }
1808 
1809   const TypeStackSlotEntries* parameters() const { return &_parameters; }
1810 
1811   uint stack_slot(int i) const {
1812     return _parameters.stack_slot(i);
1813   }
1814 
1815   void set_type(int i, Klass* k) {
1816     intptr_t current = _parameters.type(i);
1817     _parameters.set_type(i, TypeEntries::with_status((intptr_t)k, current));
1818   }
1819 
1820   virtual void clean_weak_klass_links(bool always_clean) {
1821     _parameters.clean_weak_klass_links(always_clean);
1822   }
1823 
1824   // CDS support
1825   virtual void metaspace_pointers_do(MetaspaceClosure* it) {
1826     _parameters.metaspace_pointers_do(it);
1827   }
1828 
1829   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1830 
1831   static ByteSize stack_slot_offset(int i) {
1832     return cell_offset(stack_slot_local_offset(i));
1833   }
1834 
1835   static ByteSize type_offset(int i) {
1836     return cell_offset(type_local_offset(i));
1837   }
1838 };
1839 
1840 // SpeculativeTrapData
1841 //
1842 // A SpeculativeTrapData is used to record traps due to type
1843 // speculation. It records the root of the compilation: that type
1844 // speculation is wrong in the context of one compilation (for
1845 // method1) doesn't mean it's wrong in the context of another one (for
1846 // method2). Type speculation could have more/different data in the
1847 // context of the compilation of method2 and it's worthwhile to try an
1848 // optimization that failed for compilation of method1 in the context

1879   }
1880 
1881   virtual int cell_count() const {
1882     return static_cell_count();
1883   }
1884 
1885   // Direct accessor
1886   Method* method() const {
1887     return (Method*)intptr_at(speculative_trap_method);
1888   }
1889 
1890   void set_method(Method* m) {
1891     assert(!m->is_old(), "cannot add old methods");
1892     set_intptr_at(speculative_trap_method, (intptr_t)m);
1893   }
1894 
1895   static ByteSize method_offset() {
1896     return cell_offset(speculative_trap_method);
1897   }
1898 
1899   // CDS support
1900   virtual void metaspace_pointers_do(MetaspaceClosure* it);
1901 
1902   virtual void print_data_on(outputStream* st, const char* extra = nullptr) const;
1903 };
1904 
1905 // MethodData*
1906 //
1907 // A MethodData* holds information which has been collected about
1908 // a method.  Its layout looks like this:
1909 //
1910 // -----------------------------
1911 // | header                    |
1912 // | klass                     |
1913 // -----------------------------
1914 // | method                    |
1915 // | size of the MethodData* |
1916 // -----------------------------
1917 // | Data entries...           |
1918 // |   (variable size)         |
1919 // |                           |
1920 // .                           .
1921 // .                           .

1992 class MethodData : public Metadata {
1993   friend class VMStructs;
1994   friend class JVMCIVMStructs;
1995 private:
1996   friend class ProfileData;
1997   friend class TypeEntriesAtCall;
1998   friend class ciMethodData;
1999 
2000   // If you add a new field that points to any metaspace object, you
2001   // must add this field to MethodData::metaspace_pointers_do().
2002 
2003   // Back pointer to the Method*
2004   Method* _method;
2005 
2006   // Size of this oop in bytes
2007   int _size;
2008 
2009   // Cached hint for bci_to_dp and bci_to_data
2010   int _hint_di;
2011 
2012   Mutex* volatile _extra_data_lock; // FIXME: CDS support
2013 
2014   MethodData(const methodHandle& method);
2015 public:
2016   MethodData();
2017 
2018   static MethodData* allocate(ClassLoaderData* loader_data, const methodHandle& method, TRAPS);
2019 
2020   virtual bool is_methodData() const { return true; }
2021   void initialize();
2022 
2023   // Whole-method sticky bits and flags
2024   enum {
2025     _trap_hist_limit    = Deoptimization::Reason_TRAP_HISTORY_LENGTH,
2026     _trap_hist_mask     = max_jubyte,
2027     _extra_data_count   = 4     // extra DataLayout headers, for trap history
2028   }; // Public flag values
2029 
2030   // Compiler-related counters.
2031   class CompilerCounters {
2032     friend class VMStructs;
2033     friend class JVMCIVMStructs;
2034 
2035     uint _nof_decompiles;             // count of all nmethod removals
2036     uint _nof_overflow_recompiles;    // recompile count, excluding recomp. bits
2037     uint _nof_overflow_traps;         // trap count, excluding _trap_hist
2038     uint __gap;
2039     union {
2040       intptr_t _align;
2041       // JVMCI separates trap history for OSR compilations from normal compilations
2042       u1 _array[JVMCI_ONLY(2 *) MethodData::_trap_hist_limit];
2043     } _trap_hist;
2044 
2045   public:
2046     CompilerCounters() : _nof_decompiles(0), _nof_overflow_recompiles(0), _nof_overflow_traps(0), __gap(0) {
2047 #ifndef ZERO
2048       // Some Zero platforms do not have expected alignment, and do not use
2049       // this code. static_assert would still fire and fail for them.
2050       static_assert(sizeof(_trap_hist) % HeapWordSize == 0, "align");
2051 #endif
2052       uint size_in_words = sizeof(_trap_hist) / HeapWordSize;
2053       Copy::zero_to_words((HeapWord*) &_trap_hist, size_in_words);
2054     }
2055 
2056     // Return (uint)-1 for overflow.
2057     uint trap_count(int reason) const {
2058       assert((uint)reason < ARRAY_SIZE(_trap_hist._array), "oob");
2059       return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
2060     }
2061 
2062     uint inc_trap_count(int reason) {
2063       // Count another trap, anywhere in this method.
2064       assert(reason >= 0, "must be single trap");
2065       assert((uint)reason < ARRAY_SIZE(_trap_hist._array), "oob");
2066       uint cnt1 = 1 + _trap_hist._array[reason];

2318     return &_failed_speculations;
2319   }
2320 #endif
2321 
2322 #if INCLUDE_RTM_OPT
2323   int rtm_state() const {
2324     return _rtm_state;
2325   }
2326   void set_rtm_state(RTMState rstate) {
2327     _rtm_state = (int)rstate;
2328   }
2329   void atomic_set_rtm_state(RTMState rstate) {
2330     Atomic::store(&_rtm_state, (int)rstate);
2331   }
2332 
2333   static ByteSize rtm_state_offset() {
2334     return byte_offset_of(MethodData, _rtm_state);
2335   }
2336 #endif
2337 
2338 #if INCLUDE_CDS
2339   void remove_unshareable_info();
2340   void restore_unshareable_info(TRAPS);
2341 #endif
2342 
2343   void set_would_profile(bool p)              { _would_profile = p ? profile : no_profile; }
2344   bool would_profile() const                  { return _would_profile != no_profile; }
2345 
2346   int num_loops() const                       { return _num_loops;  }
2347   void set_num_loops(short n)                 { _num_loops = n;     }
2348   int num_blocks() const                      { return _num_blocks; }
2349   void set_num_blocks(short n)                { _num_blocks = n;    }
2350 
2351   bool is_mature() const;  // consult mileage and ProfileMaturityPercentage
2352   static int mileage_of(Method* m);
2353 
2354   // Support for interprocedural escape analysis, from Thomas Kotzmann.
2355   enum EscapeFlag {
2356     estimated    = 1 << 0,
2357     return_local = 1 << 1,
2358     return_allocated = 1 << 2,
2359     allocated_escapes = 1 << 3,
2360     unknown_modified = 1 << 4
2361   };
2362 

2562   void print_value_on(outputStream* st) const;
2563 
2564   // printing support for method data
2565   void print_data_on(outputStream* st) const;
2566 
2567   const char* internal_name() const { return "{method data}"; }
2568 
2569   // verification
2570   void verify_on(outputStream* st);
2571   void verify_data_on(outputStream* st);
2572 
2573   static bool profile_parameters_for_method(const methodHandle& m);
2574   static bool profile_arguments();
2575   static bool profile_arguments_jsr292_only();
2576   static bool profile_return();
2577   static bool profile_parameters();
2578   static bool profile_return_jsr292_only();
2579 
2580   void clean_method_data(bool always_clean);
2581   void clean_weak_method_links();
2582   Mutex* extra_data_lock();
2583   void check_extra_data_locked() const NOT_DEBUG_RETURN;
2584 };
2585 
2586 #endif // SHARE_OOPS_METHODDATA_HPP
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