Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1998, 2009, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

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  */

 // Interface for generating the frame map for compiled code.  A frame map

 // describes for a specific pc whether each register and frame stack slot is:

 //   Oop         - A GC root for current frame

 //   Value       - Live non-oop, non-float value: int, either half of double

 //   Dead        - Dead; can be Zapped for debugging

 //   CalleeXX    - Callee saved; also describes which caller register is saved

 //   DerivedXX   - A derived oop; original oop is described.

 //

 // OopMapValue describes a single OopMap entry

 class frame;

 class RegisterMap;

 class DerivedPointerEntry;

 class OopMapValue: public StackObj {

   friend class VMStructs;

 private:

   short _value;

   int value() const                                 { return _value; }

   void set_value(int value)                         { _value = value; }

   short _content_reg;

 public:

   // Constants

   enum { type_bits                = 5,

          register_bits            = BitsPerShort - type_bits };

   enum { type_shift               = 0,

          register_shift           = type_bits };

   enum { type_mask                = right_n_bits(type_bits),

          type_mask_in_place       = type_mask << type_shift,

          register_mask            = right_n_bits(register_bits),

          register_mask_in_place   = register_mask << register_shift };

   enum oop_types {              // must fit in type_bits

          unused_value =0,       // powers of 2, for masking OopMapStream

          oop_value = 1,

          value_value = 2,

          narrowoop_value = 4,

          callee_saved_value = 8,

          derived_oop_value= 16 };

   // Constructors

   OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); }

   OopMapValue (VMReg reg, oop_types t) { set_reg_type(reg,t); }

   OopMapValue (VMReg reg, oop_types t, VMReg reg2) { set_reg_type(reg,t); set_content_reg(reg2); }

   OopMapValue (CompressedReadStream* stream) { read_from(stream); }

   // Archiving

   void write_on(CompressedWriteStream* stream) {

     stream->write_int(value());

     if(is_callee_saved() || is_derived_oop()) {

       stream->write_int(content_reg()->value());

     }

   }

   void read_from(CompressedReadStream* stream) {

     set_value(stream->read_int());

     if(is_callee_saved() || is_derived_oop()) {

       set_content_reg(VMRegImpl::as_VMReg(stream->read_int(), true));

     }

   }

   // Querying

   bool is_oop()               { return mask_bits(value(), type_mask_in_place) == oop_value; }

   bool is_value()             { return mask_bits(value(), type_mask_in_place) == value_value; }

   bool is_narrowoop()           { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }

   bool is_callee_saved()      { return mask_bits(value(), type_mask_in_place) == callee_saved_value; }

   bool is_derived_oop()       { return mask_bits(value(), type_mask_in_place) == derived_oop_value; }

   void set_oop()              { set_value((value() & register_mask_in_place) | oop_value); }

   void set_value()            { set_value((value() & register_mask_in_place) | value_value); }

   void set_narrowoop()          { set_value((value() & register_mask_in_place) | narrowoop_value); }

   void set_callee_saved()     { set_value((value() & register_mask_in_place) | callee_saved_value); }

   void set_derived_oop()      { set_value((value() & register_mask_in_place) | derived_oop_value); }

   VMReg reg() const { return VMRegImpl::as_VMReg(mask_bits(value(), register_mask_in_place) >> register_shift); }

   oop_types type() const      { return (oop_types)mask_bits(value(), type_mask_in_place); }

   static bool legal_vm_reg_name(VMReg p) {

     return (p->value()  == (p->value() & register_mask));

   }

   void set_reg_type(VMReg p, oop_types t) {

     set_value((p->value() << register_shift) | t);

     assert(reg() == p, "sanity check" );

     assert(type() == t, "sanity check" );

   }

   VMReg content_reg() const       { return VMRegImpl::as_VMReg(_content_reg, true); }

   void set_content_reg(VMReg r)   { _content_reg = r->value(); }

   // Physical location queries

   bool is_register_loc()      { return reg()->is_reg(); }

   bool is_stack_loc()         { return reg()->is_stack(); }

   // Returns offset from sp.

   int stack_offset() {

     assert(is_stack_loc(), "must be stack location");

     return reg()->reg2stack();

   }

   void print_on(outputStream* st) const;

   void print() const { print_on(tty); }

 };

 class OopMap: public ResourceObj {

   friend class OopMapStream;

   friend class VMStructs;

  private:

   int  _pc_offset;

   int  _omv_count;

   int  _omv_data_size;

   unsigned char* _omv_data;

   CompressedWriteStream* _write_stream;

   debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;)

   // Accessors

   unsigned char* omv_data() const             { return _omv_data; }

   void set_omv_data(unsigned char* value)     { _omv_data = value; }

   int omv_data_size() const                   { return _omv_data_size; }

   void set_omv_data_size(int value)           { _omv_data_size = value; }

   int omv_count() const                       { return _omv_count; }

   void set_omv_count(int value)               { _omv_count = value; }

   void increment_count()                      { _omv_count++; }

   CompressedWriteStream* write_stream() const { return _write_stream; }

   void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }

  private:

   enum DeepCopyToken { _deep_copy_token };

   OopMap(DeepCopyToken, OopMap* source);  // used only by deep_copy

  public:

   OopMap(int frame_size, int arg_count);

   // pc-offset handling

   int offset() const     { return _pc_offset; }

   void set_offset(int o) { _pc_offset = o; }

   // Check to avoid double insertion

   debug_only(OopMapValue::oop_types locs_used( int indx ) { return _locs_used[indx]; })

   // Construction

   // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd

   // slots to hold 4-byte values like ints and floats in the LP64 build.

   void set_oop  ( VMReg local);

   void set_value( VMReg local);

   void set_narrowoop(VMReg local);

   void set_dead ( VMReg local);

   void set_callee_saved( VMReg local, VMReg caller_machine_register );

   void set_derived_oop ( VMReg local, VMReg derived_from_local_register );

   void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);

   int heap_size() const;

   void copy_to(address addr);

   OopMap* deep_copy();

   bool has_derived_pointer() const PRODUCT_RETURN0;

   bool legal_vm_reg_name(VMReg local) {

      return OopMapValue::legal_vm_reg_name(local);

   }

   // Printing

   void print_on(outputStream* st) const;

   void print() const { print_on(tty); }

 };

 class OopMapSet : public ResourceObj {

   friend class VMStructs;

  private:

   int _om_count;

   int _om_size;

   OopMap** _om_data;

   int om_count() const              { return _om_count; }

   void set_om_count(int value)      { _om_count = value; }

   void increment_count()            { _om_count++; }

   int om_size() const               { return _om_size; }

   void set_om_size(int value)       { _om_size = value; }

   OopMap** om_data() const          { return _om_data; }

   void set_om_data(OopMap** value)  { _om_data = value; }

   void grow_om_data();

   void set(int index,OopMap* value) { assert((index == 0) || ((index > 0) && (index < om_size())),"bad index"); _om_data[index] = value; }

  public:

   OopMapSet();

   // returns the number of OopMaps in this OopMapSet

   int size() const            { return _om_count; }

   // returns the OopMap at a given index

   OopMap* at(int index) const { assert((index >= 0) && (index <= om_count()),"bad index"); return _om_data[index]; }

   // Collect OopMaps.

   void add_gc_map(int pc, OopMap* map);

   // Returns the only oop map. Used for reconstructing

   // Adapter frames during deoptimization

   OopMap* singular_oop_map();

   // returns OopMap in that is anchored to the pc

   OopMap* find_map_at_offset(int pc_offset) const;

   int heap_size() const;

   void copy_to(address addr);

   // Methods oops_do() and all_do() filter out NULL oops and

   // oop == Universe::narrow_oop_base() before passing oops

   // to closures.

   // Iterates through frame for a compiled method

   static void oops_do            (const frame* fr,

                                   const RegisterMap* reg_map, OopClosure* f);

   static void update_register_map(const frame* fr, RegisterMap *reg_map);

   // Iterates through frame for a compiled method for dead ones and values, too

   static void all_do(const frame* fr, const RegisterMap* reg_map,

                      OopClosure* oop_fn,

                      void derived_oop_fn(oop* base, oop* derived),

                      OopClosure* value_fn);

   // Printing

   void print_on(outputStream* st) const;

   void print() const { print_on(tty); }

 };

 class OopMapStream : public StackObj {

  private:

   CompressedReadStream* _stream;

   int _mask;

   int _size;

   int _position;

   bool _valid_omv;

   OopMapValue _omv;

   void find_next();

  public:

   OopMapStream(OopMap* oop_map);

   OopMapStream(OopMap* oop_map, int oop_types_mask);

   bool is_done()                        { if(!_valid_omv) { find_next(); } return !_valid_omv; }

   void next()                           { find_next(); }

   OopMapValue current()                 { return _omv; }

 };

 // Derived pointer support. This table keeps track of all derived points on a

 // stack.  It is cleared before each scavenge/GC.  During the traversal of all

 // oops, it is filled in with references to all locations that contains a

 // derived oop (assumed to be very few).  When the GC is complete, the derived

 // pointers are updated based on their base pointers new value and an offset.

 #ifdef COMPILER2

 class DerivedPointerTable : public AllStatic {

   friend class VMStructs;

  private:

    static GrowableArray<DerivedPointerEntry*>* _list;

    static bool _active;                      // do not record pointers for verify pass etc.

  public:

   static void clear();                       // Called before scavenge/GC

   static void add(oop *derived, oop *base);  // Called during scavenge/GC

   static void update_pointers();             // Called after  scavenge/GC

   static bool is_empty()                     { return _list == NULL || _list->is_empty(); }

   static bool is_active()                    { return _active; }

   static void set_active(bool value)         { _active = value; }

 };

 // A utility class to temporarily "deactivate" the DerivedPointerTable.

 // (Note: clients are responsible for any MT-safety issues)

 class DerivedPointerTableDeactivate: public StackObj {

  private:

   bool _active;

  public:

   DerivedPointerTableDeactivate() {

     _active = DerivedPointerTable::is_active();

     if (_active) {

       DerivedPointerTable::set_active(false);

     }

   }

   ~DerivedPointerTableDeactivate() {

     assert(!DerivedPointerTable::is_active(),

            "Inconsistency: not MT-safe");

     if (_active) {

       DerivedPointerTable::set_active(true);

     }

   }

 };

 #endif // COMPILER2