jdk8-mips64-public/hotspot: src/share/vm/code/exceptionHandlerTable.hpp@f90c822e73f8 (annotated)

src/share/vm/code/exceptionHandlerTable.hpp@f90c822e73f8 (annotated)

src/share/vm/code/exceptionHandlerTable.hpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

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http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 1998, 2012, 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.
  *
  */
 #ifndef SHARE_VM_CODE_EXCEPTIONHANDLERTABLE_HPP
 #define SHARE_VM_CODE_EXCEPTIONHANDLERTABLE_HPP
 #include "memory/allocation.hpp"
 #include "oops/method.hpp"
 // A HandlerTableEntry describes an individual entry of a subtable
 // of ExceptionHandlerTable. An entry consists of a pair(bci, pco),
 // where bci is the exception handler bci, and pco is the pc offset
 // relative to the nmethod code start for the compiled exception
 // handler corresponding to the (interpreted) exception handler
 // starting at bci.
 //
 // The first HandlerTableEntry of each subtable holds the length
 // and catch_pco for the subtable (the length is the number of
 // subtable entries w/o header).
 class HandlerTableEntry {
  private:
   int _bci;
   int _pco;
   int _scope_depth;
  public:
   HandlerTableEntry(int bci, int pco, int scope_depth) {
     assert( 0 <= pco, "pco must be positive");
     assert( 0 <= scope_depth, "scope_depth must be positive");
     _bci = bci;
     _pco = pco;
     _scope_depth = scope_depth;
   }
   int len() const { return _bci; } // for entry at subtable begin
   int bci() const { return _bci; }
   int pco() const { return _pco; }
   int scope_depth() const { return _scope_depth; }
 };
 // An ExceptionHandlerTable is an abstraction over a list of subtables
 // of exception handlers for CatchNodes. Each subtable has a one-entry
 // header holding length and catch_pco of the subtable, followed
 // by 'length' entries for each exception handler that can be reached
 // from the corresponding CatchNode. The catch_pco is the pc offset of
 // the CatchNode in the corresponding nmethod. Empty subtables are dis-
 // carded.
 //
 // Structure of the table:
 //
 // table    = { subtable }.
 // subtable = header entry { entry }.
 // header   = a pair (number of subtable entries, catch pc offset, [unused])
 // entry    = a pair (handler bci, handler pc offset, scope depth)
 //
 // An ExceptionHandlerTable can be created from scratch, in which case
 // it is possible to add subtables. It can also be created from an
 // nmethod (for lookup purposes) in which case the table cannot be
 // modified.
 class nmethod;
 class ExceptionHandlerTable VALUE_OBJ_CLASS_SPEC {
  private:
   HandlerTableEntry* _table;    // the table
   int                _length;   // the current length of the table
   int                _size;     // the number of allocated entries
   ReallocMark        _nesting;  // assertion check for reallocations
   // add the entry & grow the table if needed
   void add_entry(HandlerTableEntry entry);
   HandlerTableEntry* subtable_for(int catch_pco) const;
  public:
   // (compile-time) construction within compiler
   ExceptionHandlerTable(int initial_size = 8);
   // (run-time) construction from nmethod
   ExceptionHandlerTable(const nmethod* nm);
   // (compile-time) add entries
   void add_subtable(
     int                 catch_pco, // the pc offset for the CatchNode
     GrowableArray<intptr_t>* handler_bcis, // the exception handler entry point bcis
     GrowableArray<intptr_t>* scope_depths_from_top_scope,
                                            // if representing exception handlers in multiple
                                            // inlined scopes, indicates which scope relative to
                                            // the youngest/innermost one in which we are performing
                                            // the lookup; zero (or null GrowableArray) indicates
                                            // innermost scope
     GrowableArray<intptr_t>* handler_pcos  // pc offsets for the compiled handlers
   );
   // nmethod support
   int  size_in_bytes() const { return round_to(_length * sizeof(HandlerTableEntry), oopSize); }
   void copy_to(nmethod* nm);
   // lookup
   HandlerTableEntry* entry_for(int catch_pco, int handler_bci, int scope_depth) const;
   // debugging
   void print_subtable(HandlerTableEntry* t) const;
   void print() const;
   void print_subtable_for(int catch_pco) const;
 };
 // ----------------------------------------------------------------------------
 // Implicit null exception tables.  Maps an exception PC offset to a
 // continuation PC offset.  During construction it's a variable sized
 // array with a max size and current length.  When stored inside an
 // nmethod a zero length table takes no space.  This is detected by
 // nul_chk_table_size() == 0.  Otherwise the table has a length word
 // followed by pairs of <excp-offset, const-offset>.
 // Use 32-bit representation for offsets
 typedef  uint              implicit_null_entry;
 class ImplicitExceptionTable VALUE_OBJ_CLASS_SPEC {
   uint _size;
   uint _len;
   implicit_null_entry *_data;
   implicit_null_entry *adr( uint idx ) const { return &_data[2*idx]; }
   ReallocMark          _nesting;  // assertion check for reallocations
 public:
   ImplicitExceptionTable( ) :  _data(0), _size(0), _len(0) { }
   // (run-time) construction from nmethod
   ImplicitExceptionTable( const nmethod *nm );
   void set_size( uint size );
   void append( uint exec_off, uint cont_off );
   uint at( uint exec_off ) const;
   uint len() const { return _len; }
   int size_in_bytes() const { return len() == 0 ? 0 : ((2 * len() + 1) * sizeof(implicit_null_entry)); }
   void copy_to(nmethod* nm);
   void print(address base) const;
   void verify(nmethod *nm) const;
 };
 #endif // SHARE_VM_CODE_EXCEPTIONHANDLERTABLE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/code/exceptionHandlerTable.hpp@f90c822e73f8 (annotated)

src/share/vm/code/exceptionHandlerTable.hpp