diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/oops/symbol.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/oops/symbol.cpp Tue Sep 12 19:03:39 2017 +0200 @@ -0,0 +1,268 @@ +/* + * Copyright (c) 1997, 2017, 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 "logging/log.hpp" +#include "logging/logStream.hpp" +#include "memory/allocation.inline.hpp" +#include "memory/resourceArea.hpp" +#include "oops/symbol.hpp" +#include "runtime/atomic.hpp" +#include "runtime/os.hpp" + +Symbol::Symbol(const u1* name, int length, int refcount) { + _refcount = refcount; + _length = length; + _identity_hash = (short)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)*wordSize; + 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)*wordSize; + address res = (address)arena->Amalloc_4(alloc_size); + return res; +} + +void Symbol::operator delete(void *p) { + assert(((Symbol*)p)->refcount() == 0, "should not call this"); + FreeHeap(p); +} + +// ------------------------------------------------------------------ +// 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_utf8_on(outputStream* st) const { + st->print("%s", as_C_string()); +} + +void Symbol::print_symbol_on(outputStream* st) const { + char *s; + st = st ? st : tty; + { + // ResourceMark may not affect st->print(). If st is a string + // stream it could resize, using the same resource arena. + ResourceMark rm; + s = as_quoted_ascii(); + s = os::strdup(s); + } + if (s == NULL) { + st->print("(null)"); + } else { + st->print("%s", s); + os::free(s); + } +} + +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(juint 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 non-negative. If negative either + // overflow has occurred or it is a permanent symbol in a read only + // shared archive. + if (_refcount >= 0) { // not a permanent symbol + Atomic::inc(&_refcount); + NOT_PRODUCT(Atomic::inc(&_total_count);) + } +} + +void Symbol::decrement_refcount() { + if (_refcount >= 0) { // not a permanent symbol + short new_value = Atomic::add(short(-1), &_refcount); +#ifdef ASSERT + if (new_value == -1) { // we have transitioned from 0 -> -1 + print(); + assert(false, "reference count underflow for symbol"); + } +#endif + (void)new_value; + } +} + +void Symbol::metaspace_pointers_do(MetaspaceClosure* it) { + if (log_is_enabled(Trace, cds)) { + LogStream trace_stream(Log(cds)::trace()); + trace_stream.print("Iter(Symbol): %p ", this); + print_value_on(&trace_stream); + trace_stream.cr(); + } +} + +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;)