src/share/vm/oops/symbol.cpp

Thu, 11 Oct 2012 12:25:42 -0400

author
kamg
date
Thu, 11 Oct 2012 12:25:42 -0400
changeset 4245
4735d2c84362
parent 4037
da91efe96a93
child 4267
bd7a7ce2e264
permissions
-rw-r--r--

7200776: Implement default methods in interfaces
Summary: Add generic type analysis and default method selection algorithms
Reviewed-by: coleenp, acorn

     1 /*
     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    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  */
    26 #include "precompiled.hpp"
    27 #include "classfile/altHashing.hpp"
    28 #include "classfile/classLoaderData.hpp"
    29 #include "oops/symbol.hpp"
    30 #include "runtime/os.hpp"
    31 #include "memory/allocation.inline.hpp"
    32 #include "memory/resourceArea.hpp"
    34 Symbol::Symbol(const u1* name, int length, int refcount) : _refcount(refcount), _length(length) {
    35   _identity_hash = os::random();
    36   for (int i = 0; i < _length; i++) {
    37     byte_at_put(i, name[i]);
    38   }
    39 }
    41 void* Symbol::operator new(size_t sz, int len, TRAPS) {
    42   int alloc_size = size(len)*HeapWordSize;
    43   address res = (address) AllocateHeap(alloc_size, mtSymbol);
    44   return res;
    45 }
    47 void* Symbol::operator new(size_t sz, int len, Arena* arena, TRAPS) {
    48   int alloc_size = size(len)*HeapWordSize;
    49   address res = (address)arena->Amalloc(alloc_size);
    50   return res;
    51 }
    53 void* Symbol::operator new(size_t sz, int len, ClassLoaderData* loader_data, TRAPS) {
    54   address res;
    55   int alloc_size = size(len)*HeapWordSize;
    56   res = (address) Metaspace::allocate(loader_data, size(len), true,
    57                                       Metaspace::NonClassType, CHECK_NULL);
    58   return res;
    59 }
    61 void Symbol::operator delete(void *p) {
    62   assert(((Symbol*)p)->refcount() == 0, "should not call this");
    63   FreeHeap(p);
    64 }
    66 // ------------------------------------------------------------------
    67 // Symbol::equals
    68 //
    69 // Compares the symbol with a string of the given length.
    70 bool Symbol::equals(const char* str, int len) const {
    71   int l = utf8_length();
    72   if (l != len) return false;
    73   while (l-- > 0) {
    74     if (str[l] != (char) byte_at(l))
    75       return false;
    76   }
    77   assert(l == -1, "we should be at the beginning");
    78   return true;
    79 }
    82 // ------------------------------------------------------------------
    83 // Symbol::starts_with
    84 //
    85 // Tests if the symbol starts with the specified prefix of the given
    86 // length.
    87 bool Symbol::starts_with(const char* prefix, int len) const {
    88   if (len > utf8_length()) return false;
    89   while (len-- > 0) {
    90     if (prefix[len] != (char) byte_at(len))
    91       return false;
    92   }
    93   assert(len == -1, "we should be at the beginning");
    94   return true;
    95 }
    98 // ------------------------------------------------------------------
    99 // Symbol::index_of
   100 //
   101 // Finds if the given string is a substring of this symbol's utf8 bytes.
   102 // Return -1 on failure.  Otherwise return the first index where str occurs.
   103 int Symbol::index_of_at(int i, const char* str, int len) const {
   104   assert(i >= 0 && i <= utf8_length(), "oob");
   105   if (len <= 0)  return 0;
   106   char first_char = str[0];
   107   address bytes = (address) ((Symbol*)this)->base();
   108   address limit = bytes + utf8_length() - len;  // inclusive limit
   109   address scan = bytes + i;
   110   if (scan > limit)
   111     return -1;
   112   for (; scan <= limit; scan++) {
   113     scan = (address) memchr(scan, first_char, (limit + 1 - scan));
   114     if (scan == NULL)
   115       return -1;  // not found
   116     assert(scan >= bytes+i && scan <= limit, "scan oob");
   117     if (memcmp(scan, str, len) == 0)
   118       return (int)(scan - bytes);
   119   }
   120   return -1;
   121 }
   124 char* Symbol::as_C_string(char* buf, int size) const {
   125   if (size > 0) {
   126     int len = MIN2(size - 1, utf8_length());
   127     for (int i = 0; i < len; i++) {
   128       buf[i] = byte_at(i);
   129     }
   130     buf[len] = '\0';
   131   }
   132   return buf;
   133 }
   135 char* Symbol::as_C_string() const {
   136   int len = utf8_length();
   137   char* str = NEW_RESOURCE_ARRAY(char, len + 1);
   138   return as_C_string(str, len + 1);
   139 }
   141 char* Symbol::as_C_string_flexible_buffer(Thread* t,
   142                                                  char* buf, int size) const {
   143   char* str;
   144   int len = utf8_length();
   145   int buf_len = len + 1;
   146   if (size < buf_len) {
   147     str = NEW_RESOURCE_ARRAY(char, buf_len);
   148   } else {
   149     str = buf;
   150   }
   151   return as_C_string(str, buf_len);
   152 }
   154 void Symbol::print_symbol_on(outputStream* st) const {
   155   st = st ? st : tty;
   156   int length = UTF8::unicode_length((const char*)bytes(), utf8_length());
   157   const char *ptr = (const char *)bytes();
   158   jchar value;
   159   for (int index = 0; index < length; index++) {
   160     ptr = UTF8::next(ptr, &value);
   161     if (value >= 32 && value < 127 || value == '\'' || value == '\\') {
   162       st->put(value);
   163     } else {
   164       st->print("\\u%04x", value);
   165     }
   166   }
   167 }
   169 jchar* Symbol::as_unicode(int& length) const {
   170   Symbol* this_ptr = (Symbol*)this;
   171   length = UTF8::unicode_length((char*)this_ptr->bytes(), utf8_length());
   172   jchar* result = NEW_RESOURCE_ARRAY(jchar, length);
   173   if (length > 0) {
   174     UTF8::convert_to_unicode((char*)this_ptr->bytes(), result, length);
   175   }
   176   return result;
   177 }
   179 const char* Symbol::as_klass_external_name(char* buf, int size) const {
   180   if (size > 0) {
   181     char* str    = as_C_string(buf, size);
   182     int   length = (int)strlen(str);
   183     // Turn all '/'s into '.'s (also for array klasses)
   184     for (int index = 0; index < length; index++) {
   185       if (str[index] == '/') {
   186         str[index] = '.';
   187       }
   188     }
   189     return str;
   190   } else {
   191     return buf;
   192   }
   193 }
   195 const char* Symbol::as_klass_external_name() const {
   196   char* str    = as_C_string();
   197   int   length = (int)strlen(str);
   198   // Turn all '/'s into '.'s (also for array klasses)
   199   for (int index = 0; index < length; index++) {
   200     if (str[index] == '/') {
   201       str[index] = '.';
   202     }
   203   }
   204   return str;
   205 }
   207 // Alternate hashing for unbalanced symbol tables.
   208 unsigned int Symbol::new_hash(jint seed) {
   209   ResourceMark rm;
   210   // Use alternate hashing algorithm on this symbol.
   211   return AltHashing::murmur3_32(seed, (const jbyte*)as_C_string(), utf8_length());
   212 }
   214 void Symbol::print_on(outputStream* st) const {
   215   if (this == NULL) {
   216     st->print_cr("NULL");
   217   } else {
   218     st->print("Symbol: '");
   219     print_symbol_on(st);
   220     st->print("'");
   221     st->print(" count %d", refcount());
   222   }
   223 }
   225 // The print_value functions are present in all builds, to support the
   226 // disassembler and error reporting.
   227 void Symbol::print_value_on(outputStream* st) const {
   228   if (this == NULL) {
   229     st->print("NULL");
   230   } else {
   231     st->print("'");
   232     for (int i = 0; i < utf8_length(); i++) {
   233       st->print("%c", byte_at(i));
   234     }
   235     st->print("'");
   236   }
   237 }
   239 // SymbolTable prints this in its statistics
   240 NOT_PRODUCT(int Symbol::_total_count = 0;)

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