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

 /*

  * Copyright (c) 1997, 2013, 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.

  *

  */

 #include "precompiled.hpp"

 #include "classfile/altHashing.hpp"

 #include "classfile/classLoaderData.hpp"

 #include "oops/symbol.hpp"

 #include "runtime/atomic.inline.hpp"

 #include "runtime/os.hpp"

 #include "memory/allocation.inline.hpp"

 #include "memory/resourceArea.hpp"

 Symbol::Symbol(const u1* name, int length, int refcount) {

   _refcount = refcount;

   _length = length;

   _identity_hash = os::random();

   for (int i = 0; i < _length; i++) {

     byte_at_put(i, name[i]);

   }

 }

 void* Symbol::operator new(size_t sz, int len, TRAPS) throw() {

   int alloc_size = size(len)*HeapWordSize;

   address res = (address) AllocateHeap(alloc_size, mtSymbol);

   return res;

 }

 void* Symbol::operator new(size_t sz, int len, Arena* arena, TRAPS) throw() {

   int alloc_size = size(len)*HeapWordSize;

   address res = (address)arena->Amalloc(alloc_size);

   return res;

 }

 void* Symbol::operator new(size_t sz, int len, ClassLoaderData* loader_data, TRAPS) throw() {

   address res;

   int alloc_size = size(len)*HeapWordSize;

   res = (address) Metaspace::allocate(loader_data, size(len), true,

                                       MetaspaceObj::SymbolType, CHECK_NULL);

   return res;

 }

 void Symbol::operator delete(void *p) {

   assert(((Symbol*)p)->refcount() == 0, "should not call this");

   FreeHeap(p);

 }

 // ------------------------------------------------------------------

 // Symbol::equals

 //

 // Compares the symbol with a string of the given length.

 bool Symbol::equals(const char* str, int len) const {

   int l = utf8_length();

   if (l != len) return false;

   while (l-- > 0) {

     if (str[l] != (char) byte_at(l))

       return false;

   }

   assert(l == -1, "we should be at the beginning");

   return true;

 }

 // ------------------------------------------------------------------

 // Symbol::starts_with

 //

 // Tests if the symbol starts with the specified prefix of the given

 // length.

 bool Symbol::starts_with(const char* prefix, int len) const {

   if (len > utf8_length()) return false;

   while (len-- > 0) {

     if (prefix[len] != (char) byte_at(len))

       return false;

   }

   assert(len == -1, "we should be at the beginning");

   return true;

 }

 // ------------------------------------------------------------------

 // Symbol::index_of

 //

 // Finds if the given string is a substring of this symbol's utf8 bytes.

 // Return -1 on failure.  Otherwise return the first index where str occurs.

 int Symbol::index_of_at(int i, const char* str, int len) const {

   assert(i >= 0 && i <= utf8_length(), "oob");

   if (len <= 0)  return 0;

   char first_char = str[0];

   address bytes = (address) ((Symbol*)this)->base();

   address limit = bytes + utf8_length() - len;  // inclusive limit

   address scan = bytes + i;

   if (scan > limit)

     return -1;

   for (; scan <= limit; scan++) {

     scan = (address) memchr(scan, first_char, (limit + 1 - scan));

     if (scan == NULL)

       return -1;  // not found

     assert(scan >= bytes+i && scan <= limit, "scan oob");

     if (memcmp(scan, str, len) == 0)

       return (int)(scan - bytes);

   }

   return -1;

 }

 char* Symbol::as_C_string(char* buf, int size) const {

   if (size > 0) {

     int len = MIN2(size - 1, utf8_length());

     for (int i = 0; i < len; i++) {

       buf[i] = byte_at(i);

     }

     buf[len] = '\0';

   }

   return buf;

 }

 char* Symbol::as_C_string() const {

   int len = utf8_length();

   char* str = NEW_RESOURCE_ARRAY(char, len + 1);

   return as_C_string(str, len + 1);

 }

 char* Symbol::as_C_string_flexible_buffer(Thread* t,

                                                  char* buf, int size) const {

   char* str;

   int len = utf8_length();

   int buf_len = len + 1;

   if (size < buf_len) {

     str = NEW_RESOURCE_ARRAY(char, buf_len);

   } else {

     str = buf;

   }

   return as_C_string(str, buf_len);

 }

 void Symbol::print_symbol_on(outputStream* st) const {

   ResourceMark rm;

   st = st ? st : tty;

   st->print("%s", as_quoted_ascii());

 }

 char* Symbol::as_quoted_ascii() const {

   const char *ptr = (const char *)&_body[0];

   int quoted_length = UTF8::quoted_ascii_length(ptr, utf8_length());

   char* result = NEW_RESOURCE_ARRAY(char, quoted_length + 1);

   UTF8::as_quoted_ascii(ptr, utf8_length(), result, quoted_length + 1);

   return result;

 }

 jchar* Symbol::as_unicode(int& length) const {

   Symbol* this_ptr = (Symbol*)this;

   length = UTF8::unicode_length((char*)this_ptr->bytes(), utf8_length());

   jchar* result = NEW_RESOURCE_ARRAY(jchar, length);

   if (length > 0) {

     UTF8::convert_to_unicode((char*)this_ptr->bytes(), result, length);

   }

   return result;

 }

 const char* Symbol::as_klass_external_name(char* buf, int size) const {

   if (size > 0) {

     char* str    = as_C_string(buf, size);

     int   length = (int)strlen(str);

     // Turn all '/'s into '.'s (also for array klasses)

     for (int index = 0; index < length; index++) {

       if (str[index] == '/') {

         str[index] = '.';

       }

     }

     return str;

   } else {

     return buf;

   }

 }

 const char* Symbol::as_klass_external_name() const {

   char* str    = as_C_string();

   int   length = (int)strlen(str);

   // Turn all '/'s into '.'s (also for array klasses)

   for (int index = 0; index < length; index++) {

     if (str[index] == '/') {

       str[index] = '.';

     }

   }

   return str;

 }

 // Alternate hashing for unbalanced symbol tables.

 unsigned int Symbol::new_hash(jint seed) {

   ResourceMark rm;

   // Use alternate hashing algorithm on this symbol.

   return AltHashing::murmur3_32(seed, (const jbyte*)as_C_string(), utf8_length());

 }

 void Symbol::increment_refcount() {

   // Only increment the refcount if positive.  If negative either

   // overflow has occurred or it is a permanent symbol in a read only

   // shared archive.

   if (_refcount >= 0) {

     Atomic::inc(&_refcount);

     NOT_PRODUCT(Atomic::inc(&_total_count);)

   }

 }

 void Symbol::decrement_refcount() {

   if (_refcount >= 0) {

     Atomic::dec(&_refcount);

 #ifdef ASSERT

     if (_refcount < 0) {

       print();

       assert(false, "reference count underflow for symbol");

     }

 #endif

   }

 }

 void Symbol::print_on(outputStream* st) const {

   if (this == NULL) {

     st->print_cr("NULL");

   } else {

     st->print("Symbol: '");

     print_symbol_on(st);

     st->print("'");

     st->print(" count %d", refcount());

   }

 }

 // The print_value functions are present in all builds, to support the

 // disassembler and error reporting.

 void Symbol::print_value_on(outputStream* st) const {

   if (this == NULL) {

     st->print("NULL");

   } else {

     st->print("'");

     for (int i = 0; i < utf8_length(); i++) {

       st->print("%c", byte_at(i));

     }

     st->print("'");

   }

 }

 // SymbolTable prints this in its statistics

 NOT_PRODUCT(int Symbol::_total_count = 0;)