Mercurial > hg > graal-jvmci-8
diff src/share/vm/oops/symbol.cpp @ 2177:3582bf76420e
6990754: Use native memory and reference counting to implement SymbolTable
Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank
author | coleenp |
---|---|
date | Thu, 27 Jan 2011 16:11:27 -0800 |
parents | src/share/vm/oops/symbolOop.cpp@f95d63e2154a |
children | 1d1603768966 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/oops/symbol.cpp Thu Jan 27 16:11:27 2011 -0800 @@ -0,0 +1,231 @@ +/* + * Copyright (c) 1997, 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. + * + */ + + +#include "precompiled.hpp" +#include "oops/oop.inline.hpp" +#include "oops/symbol.hpp" +#include "runtime/os.hpp" +#include "memory/allocation.inline.hpp" + +Symbol::Symbol(const u1* name, int length) : _refcount(0), _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 size, int len) { + return (void *) AllocateHeap(object_size(len) * HeapWordSize, "symbol"); +} + +// ------------------------------------------------------------------ +// 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 = (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); + } +} + + +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 { + st = st ? st : tty; + int length = UTF8::unicode_length((const char*)bytes(), utf8_length()); + const char *ptr = (const char *)bytes(); + jchar value; + for (int index = 0; index < length; index++) { + ptr = UTF8::next(ptr, &value); + if (value >= 32 && value < 127 || value == '\'' || value == '\\') { + st->put(value); + } else { + st->print("\\u%04x", value); + } + } +} + +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; +} + + +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("'"); + } +} + +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 + } +} + +NOT_PRODUCT(int Symbol::_total_count = 0;)