jdk8-mips64-public/hotspot: src/share/vm/oops/methodDataOop.hpp@0b27f3512f9e (annotated)

src/share/vm/oops/methodDataOop.hpp@0b27f3512f9e (annotated)

src/share/vm/oops/methodDataOop.hpp

Wed, 04 Jun 2008 13:51:09 -0700

author: jmasa
date: Wed, 04 Jun 2008 13:51:09 -0700
changeset 624: 0b27f3512f9e
parent 513: e1e86702e43e
child 631: d1605aabd0a1
permissions: -rw-r--r--

6629727: assertion in set_trap_state() in methodDataOop.hpp is too strong.
Summary: The assertion can failure due to race conditions.
Reviewed-by: never

 /*
  * Copyright 2000-2007 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.
  *
  */
 class BytecodeStream;
 // The MethodData object collects counts and other profile information
 // during zeroth-tier (interpretive) and first-tier execution.
 // The profile is used later by compilation heuristics.  Some heuristics
 // enable use of aggressive (or "heroic") optimizations.  An aggressive
 // optimization often has a down-side, a corner case that it handles
 // poorly, but which is thought to be rare.  The profile provides
 // evidence of this rarity for a given method or even BCI.  It allows
 // the compiler to back out of the optimization at places where it
 // has historically been a poor choice.  Other heuristics try to use
 // specific information gathered about types observed at a given site.
 //
 // All data in the profile is approximate.  It is expected to be accurate
 // on the whole, but the system expects occasional inaccuraces, due to
 // counter overflow, multiprocessor races during data collection, space
 // limitations, missing MDO blocks, etc.  Bad or missing data will degrade
 // optimization quality but will not affect correctness.  Also, each MDO
 // is marked with its birth-date ("creation_mileage") which can be used
 // to assess the quality ("maturity") of its data.
 //
 // Short (<32-bit) counters are designed to overflow to a known "saturated"
 // state.  Also, certain recorded per-BCI events are given one-bit counters
 // which overflow to a saturated state which applied to all counters at
 // that BCI.  In other words, there is a small lattice which approximates
 // the ideal of an infinite-precision counter for each event at each BCI,
 // and the lattice quickly "bottoms out" in a state where all counters
 // are taken to be indefinitely large.
 //
 // The reader will find many data races in profile gathering code, starting
 // with invocation counter incrementation.  None of these races harm correct
 // execution of the compiled code.
 // DataLayout
 //
 // Overlay for generic profiling data.
 class DataLayout VALUE_OBJ_CLASS_SPEC {
 private:
   // Every data layout begins with a header.  This header
   // contains a tag, which is used to indicate the size/layout
   // of the data, 4 bits of flags, which can be used in any way,
   // 4 bits of trap history (none/one reason/many reasons),
   // and a bci, which is used to tie this piece of data to a
   // specific bci in the bytecodes.
   union {
     intptr_t _bits;
     struct {
       u1 _tag;
       u1 _flags;
       u2 _bci;
     } _struct;
   } _header;
   // The data layout has an arbitrary number of cells, each sized
   // to accomodate a pointer or an integer.
   intptr_t _cells[1];
   // Some types of data layouts need a length field.
   static bool needs_array_len(u1 tag);
 public:
   enum {
     counter_increment = 1
   };
   enum {
     cell_size = sizeof(intptr_t)
   };
   // Tag values
   enum {
     no_tag,
     bit_data_tag,
     counter_data_tag,
     jump_data_tag,
     receiver_type_data_tag,
     virtual_call_data_tag,
     ret_data_tag,
     branch_data_tag,
     multi_branch_data_tag,
     arg_info_data_tag
   };
   enum {
     // The _struct._flags word is formatted as [trap_state:4 | flags:4].
     // The trap state breaks down further as [recompile:1 | reason:3].
     // This further breakdown is defined in deoptimization.cpp.
     // See Deoptimization::trap_state_reason for an assert that
     // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT.
     //
     // The trap_state is collected only if ProfileTraps is true.
     trap_bits = 1+3,  // 3: enough to distinguish [0..Reason_RECORDED_LIMIT].
     trap_shift = BitsPerByte - trap_bits,
     trap_mask = right_n_bits(trap_bits),
     trap_mask_in_place = (trap_mask << trap_shift),
     flag_limit = trap_shift,
     flag_mask = right_n_bits(flag_limit),
     first_flag = 0
   };
   // Size computation
   static int header_size_in_bytes() {
     return cell_size;
   }
   static int header_size_in_cells() {
     return 1;
   }
   static int compute_size_in_bytes(int cell_count) {
     return header_size_in_bytes() + cell_count * cell_size;
   }
   // Initialization
   void initialize(u1 tag, u2 bci, int cell_count);
   // Accessors
   u1 tag() {
     return _header._struct._tag;
   }
   // Return a few bits of trap state.  Range is [0..trap_mask].
   // The state tells if traps with zero, one, or many reasons have occurred.
   // It also tells whether zero or many recompilations have occurred.
   // The associated trap histogram in the MDO itself tells whether
   // traps are common or not.  If a BCI shows that a trap X has
   // occurred, and the MDO shows N occurrences of X, we make the
   // simplifying assumption that all N occurrences can be blamed
   // on that BCI.
   int trap_state() {
     return ((_header._struct._flags >> trap_shift) & trap_mask);
   }
   void set_trap_state(int new_state) {
     assert(ProfileTraps, "used only under +ProfileTraps");
     uint old_flags = (_header._struct._flags & flag_mask);
     _header._struct._flags = (new_state << trap_shift) | old_flags;
   }
   u1 flags() {
     return _header._struct._flags;
   }
   u2 bci() {
     return _header._struct._bci;
   }
   void set_header(intptr_t value) {
     _header._bits = value;
   }
   void release_set_header(intptr_t value) {
     OrderAccess::release_store_ptr(&_header._bits, value);
   }
   intptr_t header() {
     return _header._bits;
   }
   void set_cell_at(int index, intptr_t value) {
     _cells[index] = value;
   }
   void release_set_cell_at(int index, intptr_t value) {
     OrderAccess::release_store_ptr(&_cells[index], value);
   }
   intptr_t cell_at(int index) {
     return _cells[index];
   }
   intptr_t* adr_cell_at(int index) {
     return &_cells[index];
   }
   oop* adr_oop_at(int index) {
     return (oop*)&(_cells[index]);
   }
   void set_flag_at(int flag_number) {
     assert(flag_number < flag_limit, "oob");
     _header._struct._flags |= (0x1 << flag_number);
   }
   bool flag_at(int flag_number) {
     assert(flag_number < flag_limit, "oob");
     return (_header._struct._flags & (0x1 << flag_number)) != 0;
   }
   // Low-level support for code generation.
   static ByteSize header_offset() {
     return byte_offset_of(DataLayout, _header);
   }
   static ByteSize tag_offset() {
     return byte_offset_of(DataLayout, _header._struct._tag);
   }
   static ByteSize flags_offset() {
     return byte_offset_of(DataLayout, _header._struct._flags);
   }
   static ByteSize bci_offset() {
     return byte_offset_of(DataLayout, _header._struct._bci);
   }
   static ByteSize cell_offset(int index) {
     return byte_offset_of(DataLayout, _cells[index]);
   }
   // Return a value which, when or-ed as a byte into _flags, sets the flag.
   static int flag_number_to_byte_constant(int flag_number) {
     assert(0 <= flag_number && flag_number < flag_limit, "oob");
     DataLayout temp; temp.set_header(0);
     temp.set_flag_at(flag_number);
     return temp._header._struct._flags;
   }
   // Return a value which, when or-ed as a word into _header, sets the flag.
   static intptr_t flag_mask_to_header_mask(int byte_constant) {
     DataLayout temp; temp.set_header(0);
     temp._header._struct._flags = byte_constant;
     return temp._header._bits;
   }
 };
 // ProfileData class hierarchy
 class ProfileData;
 class   BitData;
 class     CounterData;
 class       ReceiverTypeData;
 class         VirtualCallData;
 class       RetData;
 class   JumpData;
 class     BranchData;
 class   ArrayData;
 class     MultiBranchData;
 class     ArgInfoData;
 // ProfileData
 //
 // A ProfileData object is created to refer to a section of profiling
 // data in a structured way.
 class ProfileData : public ResourceObj {
 private:
 #ifndef PRODUCT
   enum {
     tab_width_one = 16,
     tab_width_two = 36
   };
 #endif // !PRODUCT
   // This is a pointer to a section of profiling data.
   DataLayout* _data;
 protected:
   DataLayout* data() { return _data; }
   enum {
     cell_size = DataLayout::cell_size
   };
 public:
   // How many cells are in this?
   virtual int cell_count() {
     ShouldNotReachHere();
     return -1;
   }
   // Return the size of this data.
   int size_in_bytes() {
     return DataLayout::compute_size_in_bytes(cell_count());
   }
 protected:
   // Low-level accessors for underlying data
   void set_intptr_at(int index, intptr_t value) {
     assert(0 <= index && index < cell_count(), "oob");
     data()->set_cell_at(index, value);
   }
   void release_set_intptr_at(int index, intptr_t value) {
     assert(0 <= index && index < cell_count(), "oob");
     data()->release_set_cell_at(index, value);
   }
   intptr_t intptr_at(int index) {
     assert(0 <= index && index < cell_count(), "oob");
     return data()->cell_at(index);
   }
   void set_uint_at(int index, uint value) {
     set_intptr_at(index, (intptr_t) value);
   }
   void release_set_uint_at(int index, uint value) {
     release_set_intptr_at(index, (intptr_t) value);
   }
   uint uint_at(int index) {
     return (uint)intptr_at(index);
   }
   void set_int_at(int index, int value) {
     set_intptr_at(index, (intptr_t) value);
   }
   void release_set_int_at(int index, int value) {
     release_set_intptr_at(index, (intptr_t) value);
   }
   int int_at(int index) {
     return (int)intptr_at(index);
   }
   int int_at_unchecked(int index) {
     return (int)data()->cell_at(index);
   }
   void set_oop_at(int index, oop value) {
     set_intptr_at(index, (intptr_t) value);
   }
   oop oop_at(int index) {
     return (oop)intptr_at(index);
   }
   oop* adr_oop_at(int index) {
     assert(0 <= index && index < cell_count(), "oob");
     return data()->adr_oop_at(index);
   }
   void set_flag_at(int flag_number) {
     data()->set_flag_at(flag_number);
   }
   bool flag_at(int flag_number) {
     return data()->flag_at(flag_number);
   }
   // two convenient imports for use by subclasses:
   static ByteSize cell_offset(int index) {
     return DataLayout::cell_offset(index);
   }
   static int flag_number_to_byte_constant(int flag_number) {
     return DataLayout::flag_number_to_byte_constant(flag_number);
   }
   ProfileData(DataLayout* data) {
     _data = data;
   }
 public:
   // Constructor for invalid ProfileData.
   ProfileData();
   u2 bci() {
     return data()->bci();
   }
   address dp() {
     return (address)_data;
   }
   int trap_state() {
     return data()->trap_state();
   }
   void set_trap_state(int new_state) {
     data()->set_trap_state(new_state);
   }
   // Type checking
   virtual bool is_BitData()         { return false; }
   virtual bool is_CounterData()     { return false; }
   virtual bool is_JumpData()        { return false; }
   virtual bool is_ReceiverTypeData(){ return false; }
   virtual bool is_VirtualCallData() { return false; }
   virtual bool is_RetData()         { return false; }
   virtual bool is_BranchData()      { return false; }
   virtual bool is_ArrayData()       { return false; }
   virtual bool is_MultiBranchData() { return false; }
   virtual bool is_ArgInfoData()     { return false; }
   BitData* as_BitData() {
     assert(is_BitData(), "wrong type");
     return is_BitData()         ? (BitData*)        this : NULL;
   }
   CounterData* as_CounterData() {
     assert(is_CounterData(), "wrong type");
     return is_CounterData()     ? (CounterData*)    this : NULL;
   }
   JumpData* as_JumpData() {
     assert(is_JumpData(), "wrong type");
     return is_JumpData()        ? (JumpData*)       this : NULL;
   }
   ReceiverTypeData* as_ReceiverTypeData() {
     assert(is_ReceiverTypeData(), "wrong type");
     return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL;
   }
   VirtualCallData* as_VirtualCallData() {
     assert(is_VirtualCallData(), "wrong type");
     return is_VirtualCallData() ? (VirtualCallData*)this : NULL;
   }
   RetData* as_RetData() {
     assert(is_RetData(), "wrong type");
     return is_RetData()         ? (RetData*)        this : NULL;
   }
   BranchData* as_BranchData() {
     assert(is_BranchData(), "wrong type");
     return is_BranchData()      ? (BranchData*)     this : NULL;
   }
   ArrayData* as_ArrayData() {
     assert(is_ArrayData(), "wrong type");
     return is_ArrayData()       ? (ArrayData*)      this : NULL;
   }
   MultiBranchData* as_MultiBranchData() {
     assert(is_MultiBranchData(), "wrong type");
     return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
   }
   ArgInfoData* as_ArgInfoData() {
     assert(is_ArgInfoData(), "wrong type");
     return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
   }
   // Subclass specific initialization
   virtual void post_initialize(BytecodeStream* stream, methodDataOop mdo) {}
   // GC support
   virtual void follow_contents() {}
   virtual void oop_iterate(OopClosure* blk) {}
   virtual void oop_iterate_m(OopClosure* blk, MemRegion mr) {}
   virtual void adjust_pointers() {}
 #ifndef SERIALGC
   // Parallel old support
   virtual void follow_contents(ParCompactionManager* cm) {}
   virtual void update_pointers() {}
   virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr) {}
 #endif // SERIALGC
   // CI translation: ProfileData can represent both MethodDataOop data
   // as well as CIMethodData data. This function is provided for translating
   // an oop in a ProfileData to the ci equivalent. Generally speaking,
   // most ProfileData don't require any translation, so we provide the null
   // translation here, and the required translators are in the ci subclasses.
   virtual void translate_from(ProfileData* data) {}
   virtual void print_data_on(outputStream* st) {
     ShouldNotReachHere();
   }
 #ifndef PRODUCT
   void print_shared(outputStream* st, const char* name);
   void tab(outputStream* st);
 #endif
 };
 // BitData
 //
 // A BitData holds a flag or two in its header.
 class BitData : public ProfileData {
 protected:
   enum {
     // null_seen:
     //  saw a null operand (cast/aastore/instanceof)
     null_seen_flag              = DataLayout::first_flag + 0
   };
   enum { bit_cell_count = 0 };  // no additional data fields needed.
 public:
   BitData(DataLayout* layout) : ProfileData(layout) {
   }
   virtual bool is_BitData() { return true; }
   static int static_cell_count() {
     return bit_cell_count;
   }
   virtual int cell_count() {
     return static_cell_count();
   }
   // Accessor
   // The null_seen flag bit is specially known to the interpreter.
   // Consulting it allows the compiler to avoid setting up null_check traps.
   bool null_seen()     { return flag_at(null_seen_flag); }
   void set_null_seen()    { set_flag_at(null_seen_flag); }
   // Code generation support
   static int null_seen_byte_constant() {
     return flag_number_to_byte_constant(null_seen_flag);
   }
   static ByteSize bit_data_size() {
     return cell_offset(bit_cell_count);
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 // CounterData
 //
 // A CounterData corresponds to a simple counter.
 class CounterData : public BitData {
 protected:
   enum {
     count_off,
     counter_cell_count
   };
 public:
   CounterData(DataLayout* layout) : BitData(layout) {}
   virtual bool is_CounterData() { return true; }
   static int static_cell_count() {
     return counter_cell_count;
   }
   virtual int cell_count() {
     return static_cell_count();
   }
   // Direct accessor
   uint count() {
     return uint_at(count_off);
   }
   // Code generation support
   static ByteSize count_offset() {
     return cell_offset(count_off);
   }
   static ByteSize counter_data_size() {
     return cell_offset(counter_cell_count);
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 // JumpData
 //
 // A JumpData is used to access profiling information for a direct
 // branch.  It is a counter, used for counting the number of branches,
 // plus a data displacement, used for realigning the data pointer to
 // the corresponding target bci.
 class JumpData : public ProfileData {
 protected:
   enum {
     taken_off_set,
     displacement_off_set,
     jump_cell_count
   };
   void set_displacement(int displacement) {
     set_int_at(displacement_off_set, displacement);
   }
 public:
   JumpData(DataLayout* layout) : ProfileData(layout) {
     assert(layout->tag() == DataLayout::jump_data_tag ||
       layout->tag() == DataLayout::branch_data_tag, "wrong type");
   }
   virtual bool is_JumpData() { return true; }
   static int static_cell_count() {
     return jump_cell_count;
   }
   virtual int cell_count() {
     return static_cell_count();
   }
   // Direct accessor
   uint taken() {
     return uint_at(taken_off_set);
   }
   // Saturating counter
   uint inc_taken() {
     uint cnt = taken() + 1;
     // Did we wrap? Will compiler screw us??
     if (cnt == 0) cnt--;
     set_uint_at(taken_off_set, cnt);
     return cnt;
   }
   int displacement() {
     return int_at(displacement_off_set);
   }
   // Code generation support
   static ByteSize taken_offset() {
     return cell_offset(taken_off_set);
   }
   static ByteSize displacement_offset() {
     return cell_offset(displacement_off_set);
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 // ReceiverTypeData
 //
 // A ReceiverTypeData is used to access profiling information about a
 // dynamic type check.  It consists of a counter which counts the total times
 // that the check is reached, and a series of (klassOop, count) pairs
 // which are used to store a type profile for the receiver of the check.
 class ReceiverTypeData : public CounterData {
 protected:
   enum {
     receiver0_offset = counter_cell_count,
     count0_offset,
     receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
   };
 public:
   ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
     assert(layout->tag() == DataLayout::receiver_type_data_tag ||
            layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
   }
   virtual bool is_ReceiverTypeData() { return true; }
   static int static_cell_count() {
     return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
   }
   virtual int cell_count() {
     return static_cell_count();
   }
   // Direct accessors
   static uint row_limit() {
     return TypeProfileWidth;
   }
   static int receiver_cell_index(uint row) {
     return receiver0_offset + row * receiver_type_row_cell_count;
   }
   static int receiver_count_cell_index(uint row) {
     return count0_offset + row * receiver_type_row_cell_count;
   }
   // Get the receiver at row.  The 'unchecked' version is needed by parallel old
   // gc; it does not assert the receiver is a klass.  During compaction of the
   // perm gen, the klass may already have moved, so the is_klass() predicate
   // would fail.  The 'normal' version should be used whenever possible.
   klassOop receiver_unchecked(uint row) {
     assert(row < row_limit(), "oob");
     oop recv = oop_at(receiver_cell_index(row));
     return (klassOop)recv;
   }
   klassOop receiver(uint row) {
     klassOop recv = receiver_unchecked(row);
     assert(recv == NULL || ((oop)recv)->is_klass(), "wrong type");
     return recv;
   }
   uint receiver_count(uint row) {
     assert(row < row_limit(), "oob");
     return uint_at(receiver_count_cell_index(row));
   }
   // Code generation support
   static ByteSize receiver_offset(uint row) {
     return cell_offset(receiver_cell_index(row));
   }
   static ByteSize receiver_count_offset(uint row) {
     return cell_offset(receiver_count_cell_index(row));
   }
   static ByteSize receiver_type_data_size() {
     return cell_offset(static_cell_count());
   }
   // GC support
   virtual void follow_contents();
   virtual void oop_iterate(OopClosure* blk);
   virtual void oop_iterate_m(OopClosure* blk, MemRegion mr);
   virtual void adjust_pointers();
 #ifndef SERIALGC
   // Parallel old support
   virtual void follow_contents(ParCompactionManager* cm);
   virtual void update_pointers();
   virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr);
 #endif // SERIALGC
   oop* adr_receiver(uint row) {
     return adr_oop_at(receiver_cell_index(row));
   }
 #ifndef PRODUCT
   void print_receiver_data_on(outputStream* st);
   void print_data_on(outputStream* st);
 #endif
 };
 // VirtualCallData
 //
 // A VirtualCallData is used to access profiling information about a
 // virtual call.  For now, it has nothing more than a ReceiverTypeData.
 class VirtualCallData : public ReceiverTypeData {
 public:
   VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
     assert(layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
   }
   virtual bool is_VirtualCallData() { return true; }
   static int static_cell_count() {
     // At this point we could add more profile state, e.g., for arguments.
     // But for now it's the same size as the base record type.
     return ReceiverTypeData::static_cell_count();
   }
   virtual int cell_count() {
     return static_cell_count();
   }
   // Direct accessors
   static ByteSize virtual_call_data_size() {
     return cell_offset(static_cell_count());
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 // RetData
 //
 // A RetData is used to access profiling information for a ret bytecode.
 // It is composed of a count of the number of times that the ret has
 // been executed, followed by a series of triples of the form
 // (bci, count, di) which count the number of times that some bci was the
 // target of the ret and cache a corresponding data displacement.
 class RetData : public CounterData {
 protected:
   enum {
     bci0_offset = counter_cell_count,
     count0_offset,
     displacement0_offset,
     ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
   };
   void set_bci(uint row, int bci) {
     assert((uint)row < row_limit(), "oob");
     set_int_at(bci0_offset + row * ret_row_cell_count, bci);
   }
   void release_set_bci(uint row, int bci) {
     assert((uint)row < row_limit(), "oob");
     // 'release' when setting the bci acts as a valid flag for other
     // threads wrt bci_count and bci_displacement.
     release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
   }
   void set_bci_count(uint row, uint count) {
     assert((uint)row < row_limit(), "oob");
     set_uint_at(count0_offset + row * ret_row_cell_count, count);
   }
   void set_bci_displacement(uint row, int disp) {
     set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
   }
 public:
   RetData(DataLayout* layout) : CounterData(layout) {
     assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
   }
   virtual bool is_RetData() { return true; }
   enum {
     no_bci = -1 // value of bci when bci1/2 are not in use.
   };
   static int static_cell_count() {
     return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
   }
   virtual int cell_count() {
     return static_cell_count();
   }
   static uint row_limit() {
     return BciProfileWidth;
   }
   static int bci_cell_index(uint row) {
     return bci0_offset + row * ret_row_cell_count;
   }
   static int bci_count_cell_index(uint row) {
     return count0_offset + row * ret_row_cell_count;
   }
   static int bci_displacement_cell_index(uint row) {
     return displacement0_offset + row * ret_row_cell_count;
   }
   // Direct accessors
   int bci(uint row) {
     return int_at(bci_cell_index(row));
   }
   uint bci_count(uint row) {
     return uint_at(bci_count_cell_index(row));
   }
   int bci_displacement(uint row) {
     return int_at(bci_displacement_cell_index(row));
   }
   // Interpreter Runtime support
   address fixup_ret(int return_bci, methodDataHandle mdo);
   // Code generation support
   static ByteSize bci_offset(uint row) {
     return cell_offset(bci_cell_index(row));
   }
   static ByteSize bci_count_offset(uint row) {
     return cell_offset(bci_count_cell_index(row));
   }
   static ByteSize bci_displacement_offset(uint row) {
     return cell_offset(bci_displacement_cell_index(row));
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 // BranchData
 //
 // A BranchData is used to access profiling data for a two-way branch.
 // It consists of taken and not_taken counts as well as a data displacement
 // for the taken case.
 class BranchData : public JumpData {
 protected:
   enum {
     not_taken_off_set = jump_cell_count,
     branch_cell_count
   };
   void set_displacement(int displacement) {
     set_int_at(displacement_off_set, displacement);
   }
 public:
   BranchData(DataLayout* layout) : JumpData(layout) {
     assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
   }
   virtual bool is_BranchData() { return true; }
   static int static_cell_count() {
     return branch_cell_count;
   }
   virtual int cell_count() {
     return static_cell_count();
   }
   // Direct accessor
   uint not_taken() {
     return uint_at(not_taken_off_set);
   }
   uint inc_not_taken() {
     uint cnt = not_taken() + 1;
     // Did we wrap? Will compiler screw us??
     if (cnt == 0) cnt--;
     set_uint_at(not_taken_off_set, cnt);
     return cnt;
   }
   // Code generation support
   static ByteSize not_taken_offset() {
     return cell_offset(not_taken_off_set);
   }
   static ByteSize branch_data_size() {
     return cell_offset(branch_cell_count);
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 // ArrayData
 //
 // A ArrayData is a base class for accessing profiling data which does
 // not have a statically known size.  It consists of an array length
 // and an array start.
 class ArrayData : public ProfileData {
 protected:
   friend class DataLayout;
   enum {
     array_len_off_set,
     array_start_off_set
   };
   uint array_uint_at(int index) {
     int aindex = index + array_start_off_set;
     return uint_at(aindex);
   }
   int array_int_at(int index) {
     int aindex = index + array_start_off_set;
     return int_at(aindex);
   }
   oop array_oop_at(int index) {
     int aindex = index + array_start_off_set;
     return oop_at(aindex);
   }
   void array_set_int_at(int index, int value) {
     int aindex = index + array_start_off_set;
     set_int_at(aindex, value);
   }
   // Code generation support for subclasses.
   static ByteSize array_element_offset(int index) {
     return cell_offset(array_start_off_set + index);
   }
 public:
   ArrayData(DataLayout* layout) : ProfileData(layout) {}
   virtual bool is_ArrayData() { return true; }
   static int static_cell_count() {
     return -1;
   }
   int array_len() {
     return int_at_unchecked(array_len_off_set);
   }
   virtual int cell_count() {
     return array_len() + 1;
   }
   // Code generation support
   static ByteSize array_len_offset() {
     return cell_offset(array_len_off_set);
   }
   static ByteSize array_start_offset() {
     return cell_offset(array_start_off_set);
   }
 };
 // MultiBranchData
 //
 // A MultiBranchData is used to access profiling information for
 // a multi-way branch (*switch bytecodes).  It consists of a series
 // of (count, displacement) pairs, which count the number of times each
 // case was taken and specify the data displacment for each branch target.
 class MultiBranchData : public ArrayData {
 protected:
   enum {
     default_count_off_set,
     default_disaplacement_off_set,
     case_array_start
   };
   enum {
     relative_count_off_set,
     relative_displacement_off_set,
     per_case_cell_count
   };
   void set_default_displacement(int displacement) {
     array_set_int_at(default_disaplacement_off_set, displacement);
   }
   void set_displacement_at(int index, int displacement) {
     array_set_int_at(case_array_start +
                      index * per_case_cell_count +
                      relative_displacement_off_set,
                      displacement);
   }
 public:
   MultiBranchData(DataLayout* layout) : ArrayData(layout) {
     assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
   }
   virtual bool is_MultiBranchData() { return true; }
   static int compute_cell_count(BytecodeStream* stream);
   int number_of_cases() {
     int alen = array_len() - 2; // get rid of default case here.
     assert(alen % per_case_cell_count == 0, "must be even");
     return (alen / per_case_cell_count);
   }
   uint default_count() {
     return array_uint_at(default_count_off_set);
   }
   int default_displacement() {
     return array_int_at(default_disaplacement_off_set);
   }
   uint count_at(int index) {
     return array_uint_at(case_array_start +
                          index * per_case_cell_count +
                          relative_count_off_set);
   }
   int displacement_at(int index) {
     return array_int_at(case_array_start +
                         index * per_case_cell_count +
                         relative_displacement_off_set);
   }
   // Code generation support
   static ByteSize default_count_offset() {
     return array_element_offset(default_count_off_set);
   }
   static ByteSize default_displacement_offset() {
     return array_element_offset(default_disaplacement_off_set);
   }
   static ByteSize case_count_offset(int index) {
     return case_array_offset() +
            (per_case_size() * index) +
            relative_count_offset();
   }
   static ByteSize case_array_offset() {
     return array_element_offset(case_array_start);
   }
   static ByteSize per_case_size() {
     return in_ByteSize(per_case_cell_count) * cell_size;
   }
   static ByteSize relative_count_offset() {
     return in_ByteSize(relative_count_off_set) * cell_size;
   }
   static ByteSize relative_displacement_offset() {
     return in_ByteSize(relative_displacement_off_set) * cell_size;
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 class ArgInfoData : public ArrayData {
 public:
   ArgInfoData(DataLayout* layout) : ArrayData(layout) {
     assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
   }
   virtual bool is_ArgInfoData() { return true; }
   int number_of_args() {
     return array_len();
   }
   uint arg_modified(int arg) {
     return array_uint_at(arg);
   }
   void set_arg_modified(int arg, uint val) {
     array_set_int_at(arg, val);
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st);
 #endif
 };
 // methodDataOop
 //
 // A methodDataOop holds information which has been collected about
 // a method.  Its layout looks like this:
 //
 // -----------------------------
 // | header                    |
 // | klass                     |
 // -----------------------------
 // | method                    |
 // | size of the methodDataOop |
 // -----------------------------
 // | Data entries...           |
 // |   (variable size)         |
 // |                           |
 // .                           .
 // .                           .
 // .                           .
 // |                           |
 // -----------------------------
 //
 // The data entry area is a heterogeneous array of DataLayouts. Each
 // DataLayout in the array corresponds to a specific bytecode in the
 // method.  The entries in the array are sorted by the corresponding
 // bytecode.  Access to the data is via resource-allocated ProfileData,
 // which point to the underlying blocks of DataLayout structures.
 //
 // During interpretation, if profiling in enabled, the interpreter
 // maintains a method data pointer (mdp), which points at the entry
 // in the array corresponding to the current bci.  In the course of
 // intepretation, when a bytecode is encountered that has profile data
 // associated with it, the entry pointed to by mdp is updated, then the
 // mdp is adjusted to point to the next appropriate DataLayout.  If mdp
 // is NULL to begin with, the interpreter assumes that the current method
 // is not (yet) being profiled.
 //
 // In methodDataOop parlance, "dp" is a "data pointer", the actual address
 // of a DataLayout element.  A "di" is a "data index", the offset in bytes
 // from the base of the data entry array.  A "displacement" is the byte offset
 // in certain ProfileData objects that indicate the amount the mdp must be
 // adjusted in the event of a change in control flow.
 //
 class methodDataOopDesc : public oopDesc {
   friend class VMStructs;
 private:
   friend class ProfileData;
   // Back pointer to the methodOop
   methodOop _method;
   // Size of this oop in bytes
   int _size;
   // Cached hint for bci_to_dp and bci_to_data
   int _hint_di;
   // Whole-method sticky bits and flags
 public:
   enum {
     _trap_hist_limit    = 16,   // decoupled from Deoptimization::Reason_LIMIT
     _trap_hist_mask     = max_jubyte,
     _extra_data_count   = 4     // extra DataLayout headers, for trap history
   }; // Public flag values
 private:
   uint _nof_decompiles;             // count of all nmethod removals
   uint _nof_overflow_recompiles;    // recompile count, excluding recomp. bits
   uint _nof_overflow_traps;         // trap count, excluding _trap_hist
   union {
     intptr_t _align;
     u1 _array[_trap_hist_limit];
   } _trap_hist;
   // Support for interprocedural escape analysis, from Thomas Kotzmann.
   intx              _eflags;          // flags on escape information
   intx              _arg_local;       // bit set of non-escaping arguments
   intx              _arg_stack;       // bit set of stack-allocatable arguments
   intx              _arg_returned;    // bit set of returned arguments
   int _creation_mileage;            // method mileage at MDO creation
   // Size of _data array in bytes.  (Excludes header and extra_data fields.)
   int _data_size;
   // Beginning of the data entries
   intptr_t _data[1];
   // Helper for size computation
   static int compute_data_size(BytecodeStream* stream);
   static int bytecode_cell_count(Bytecodes::Code code);
   enum { no_profile_data = -1, variable_cell_count = -2 };
   // Helper for initialization
   DataLayout* data_layout_at(int data_index) {
     assert(data_index % sizeof(intptr_t) == 0, "unaligned");
     return (DataLayout*) (((address)_data) + data_index);
   }
   // Initialize an individual data segment.  Returns the size of
   // the segment in bytes.
   int initialize_data(BytecodeStream* stream, int data_index);
   // Helper for data_at
   DataLayout* limit_data_position() {
     return (DataLayout*)((address)data_base() + _data_size);
   }
   bool out_of_bounds(int data_index) {
     return data_index >= data_size();
   }
   // Give each of the data entries a chance to perform specific
   // data initialization.
   void post_initialize(BytecodeStream* stream);
   // hint accessors
   int      hint_di() const  { return _hint_di; }
   void set_hint_di(int di)  {
     assert(!out_of_bounds(di), "hint_di out of bounds");
     _hint_di = di;
   }
   ProfileData* data_before(int bci) {
     // avoid SEGV on this edge case
     if (data_size() == 0)
       return NULL;
     int hint = hint_di();
     if (data_layout_at(hint)->bci() <= bci)
       return data_at(hint);
     return first_data();
   }
   // What is the index of the first data entry?
   int first_di() { return 0; }
   // Find or create an extra ProfileData:
   ProfileData* bci_to_extra_data(int bci, bool create_if_missing);
   // return the argument info cell
   ArgInfoData *arg_info();
 public:
   static int header_size() {
     return sizeof(methodDataOopDesc)/wordSize;
   }
   // Compute the size of a methodDataOop before it is created.
   static int compute_allocation_size_in_bytes(methodHandle method);
   static int compute_allocation_size_in_words(methodHandle method);
   static int compute_extra_data_count(int data_size, int empty_bc_count);
   // Determine if a given bytecode can have profile information.
   static bool bytecode_has_profile(Bytecodes::Code code) {
     return bytecode_cell_count(code) != no_profile_data;
   }
   // Perform initialization of a new methodDataOop
   void initialize(methodHandle method);
   // My size
   int object_size_in_bytes() { return _size; }
   int object_size() {
     return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord);
   }
   int      creation_mileage() const  { return _creation_mileage; }
   void set_creation_mileage(int x)   { _creation_mileage = x; }
   bool is_mature() const;  // consult mileage and ProfileMaturityPercentage
   static int mileage_of(methodOop m);
   // Support for interprocedural escape analysis, from Thomas Kotzmann.
   enum EscapeFlag {
     estimated    = 1 << 0,
     return_local = 1 << 1,
     return_allocated = 1 << 2,
     allocated_escapes = 1 << 3,
     unknown_modified = 1 << 4
   };
   intx eflags()                                  { return _eflags; }
   intx arg_local()                               { return _arg_local; }
   intx arg_stack()                               { return _arg_stack; }
   intx arg_returned()                            { return _arg_returned; }
   uint arg_modified(int a)                       { ArgInfoData *aid = arg_info();
                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
                                                    return aid->arg_modified(a); }
   void set_eflags(intx v)                        { _eflags = v; }
   void set_arg_local(intx v)                     { _arg_local = v; }
   void set_arg_stack(intx v)                     { _arg_stack = v; }
   void set_arg_returned(intx v)                  { _arg_returned = v; }
   void set_arg_modified(int a, uint v)           { ArgInfoData *aid = arg_info();
                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
                                                    aid->set_arg_modified(a, v); }
   void clear_escape_info()                       { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
   // Location and size of data area
   address data_base() const {
     return (address) _data;
   }
   int data_size() {
     return _data_size;
   }
   // Accessors
   methodOop method() { return _method; }
   // Get the data at an arbitrary (sort of) data index.
   ProfileData* data_at(int data_index);
   // Walk through the data in order.
   ProfileData* first_data() { return data_at(first_di()); }
   ProfileData* next_data(ProfileData* current);
   bool is_valid(ProfileData* current) { return current != NULL; }
   // Convert a dp (data pointer) to a di (data index).
   int dp_to_di(address dp) {
     return dp - ((address)_data);
   }
   address di_to_dp(int di) {
     return (address)data_layout_at(di);
   }
   // bci to di/dp conversion.
   address bci_to_dp(int bci);
   int bci_to_di(int bci) {
     return dp_to_di(bci_to_dp(bci));
   }
   // Get the data at an arbitrary bci, or NULL if there is none.
   ProfileData* bci_to_data(int bci);
   // Same, but try to create an extra_data record if one is needed:
   ProfileData* allocate_bci_to_data(int bci) {
     ProfileData* data = bci_to_data(bci);
     return (data != NULL) ? data : bci_to_extra_data(bci, true);
   }
   // Add a handful of extra data records, for trap tracking.
   DataLayout* extra_data_base() { return limit_data_position(); }
   DataLayout* extra_data_limit() { return (DataLayout*)((address)this + object_size_in_bytes()); }
   int extra_data_size() { return (address)extra_data_limit()
                                - (address)extra_data_base(); }
   static DataLayout* next_extra(DataLayout* dp) { return (DataLayout*)((address)dp + in_bytes(DataLayout::cell_offset(0))); }
   // Return (uint)-1 for overflow.
   uint trap_count(int reason) const {
     assert((uint)reason < _trap_hist_limit, "oob");
     return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
   }
   // For loops:
   static uint trap_reason_limit() { return _trap_hist_limit; }
   static uint trap_count_limit()  { return _trap_hist_mask; }
   uint inc_trap_count(int reason) {
     // Count another trap, anywhere in this method.
     assert(reason >= 0, "must be single trap");
     if ((uint)reason < _trap_hist_limit) {
       uint cnt1 = 1 + _trap_hist._array[reason];
       if ((cnt1 & _trap_hist_mask) != 0) {  // if no counter overflow...
         _trap_hist._array[reason] = cnt1;
         return cnt1;
       } else {
         return _trap_hist_mask + (++_nof_overflow_traps);
       }
     } else {
       // Could not represent the count in the histogram.
       return (++_nof_overflow_traps);
     }
   }
   uint overflow_trap_count() const {
     return _nof_overflow_traps;
   }
   uint overflow_recompile_count() const {
     return _nof_overflow_recompiles;
   }
   void inc_overflow_recompile_count() {
     _nof_overflow_recompiles += 1;
   }
   uint decompile_count() const {
     return _nof_decompiles;
   }
   void inc_decompile_count() {
     _nof_decompiles += 1;
   }
   // Support for code generation
   static ByteSize data_offset() {
     return byte_offset_of(methodDataOopDesc, _data[0]);
   }
   // GC support
   oop* adr_method() const { return (oop*)&_method; }
   bool object_is_parsable() const { return _size != 0; }
   void set_object_is_parsable(int object_size_in_bytes) { _size = object_size_in_bytes; }
 #ifndef PRODUCT
   // printing support for method data
   void print_data_on(outputStream* st);
 #endif
   // verification
   void verify_data_on(outputStream* st);
 };

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/oops/methodDataOop.hpp@0b27f3512f9e (annotated)

src/share/vm/oops/methodDataOop.hpp