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src/share/vm/oops/symbolOop.hpp@8012aa3ccede (annotated)

src/share/vm/oops/symbolOop.hpp

Thu, 13 Jan 2011 22:15:41 -0800

author

never

date

Thu, 13 Jan 2011 22:15:41 -0800

changeset 2462

8012aa3ccede

parent 2314

f95d63e2154a

permissions

-rw-r--r--

4926272: methodOopDesc::method_from_bcp is unsafe
Reviewed-by: coleenp, jrose, kvn, dcubed

duke@435	1	/*
stefank@2314	2	* Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#ifndef SHARE_VM_OOPS_SYMBOLOOP_HPP
stefank@2314	26	#define SHARE_VM_OOPS_SYMBOLOOP_HPP
stefank@2314	27
stefank@2314	28	#include "oops/typeArrayOop.hpp"
stefank@2314	29	#include "utilities/utf8.hpp"
stefank@2314	30
duke@435	31	// A symbolOop is a canonicalized string.
duke@435	32	// All symbolOops reside in global symbolTable.
duke@435	33	// See oopFactory::new_symbol for how to allocate a symbolOop
duke@435	34
duke@435	35	class symbolOopDesc : public oopDesc {
duke@435	36	friend class VMStructs;
duke@435	37	private:
duke@435	38	unsigned short _length; // number of UTF8 characters in the symbol
duke@435	39	jbyte _body[1];
duke@435	40
duke@435	41	enum {
duke@435	42	// max_symbol_length is constrained by type of _length
duke@435	43	max_symbol_length = (1 << 16) -1
duke@435	44	};
duke@435	45	public:
duke@435	46
duke@435	47	// Low-level access (used with care, since not GC-safe)
duke@435	48	jbyte* base() { return &_body[0]; }
duke@435	49
duke@435	50
duke@435	51	// Returns the largest size symbol we can safely hold.
duke@435	52	static int max_length() {
duke@435	53	return max_symbol_length;
duke@435	54	}
duke@435	55
duke@435	56	static int object_size(int length) {
duke@435	57	int size = header_size() + (sizeof(unsigned short) + length + HeapWordSize - 1) / HeapWordSize;
duke@435	58	return align_object_size(size);
duke@435	59	}
duke@435	60
duke@435	61	int object_size() { return object_size(utf8_length()); }
duke@435	62
duke@435	63	int byte_at(int index) const {
duke@435	64	assert(index >=0 && index < _length, "symbol index overflow");
duke@435	65	return ((symbolOopDesc*)this)->base()[index];
duke@435	66	}
duke@435	67
duke@435	68	void byte_at_put(int index, int value) {
duke@435	69	assert(index >=0 && index < _length, "symbol index overflow");
duke@435	70	((symbolOopDesc*)this)->base()[index] = value;
duke@435	71	}
duke@435	72
duke@435	73	jbyte* bytes() { return base(); }
duke@435	74
duke@435	75	int utf8_length() const { return _length; }
duke@435	76
duke@435	77	void set_utf8_length(int len) { _length = len; }
duke@435	78
twisti@1573	79	// Compares the symbol with a string.
duke@435	80	bool equals(const char* str, int len) const;
twisti@1573	81	bool equals(const char* str) const { return equals(str, (int) strlen(str)); }
twisti@1573	82
twisti@1573	83	// Tests if the symbol starts with the given prefix.
twisti@1573	84	bool starts_with(const char* prefix, int len) const;
twisti@1573	85	bool starts_with(const char* prefix) const {
twisti@1573	86	return starts_with(prefix, (int) strlen(prefix));
twisti@1573	87	}
twisti@1573	88
twisti@1573	89	// Tests if the symbol starts with the given prefix.
twisti@1573	90	int index_of_at(int i, const char* str, int len) const;
twisti@1573	91	int index_of_at(int i, const char* str) const {
twisti@1573	92	return index_of_at(i, str, (int) strlen(str));
twisti@1573	93	}
duke@435	94
duke@435	95	// Three-way compare for sorting; returns -1/0/1 if receiver is </==/> than arg
duke@435	96	// note that the ordering is not alfabetical
duke@435	97	inline int fast_compare(symbolOop other) const;
duke@435	98
duke@435	99	// Returns receiver converted to null-terminated UTF-8 string; string is
duke@435	100	// allocated in resource area, or in the char buffer provided by caller.
duke@435	101	char* as_C_string() const;
duke@435	102	char* as_C_string(char* buf, int size) const;
duke@435	103	// Use buf if needed buffer length is <= size.
duke@435	104	char* as_C_string_flexible_buffer(Thread* t, char* buf, int size) const;
duke@435	105
duke@435	106
duke@435	107	// Returns a null terminated utf8 string in a resource array
duke@435	108	char* as_utf8() const { return as_C_string(); }
duke@435	109	char* as_utf8_flexible_buffer(Thread* t, char* buf, int size) const {
duke@435	110	return as_C_string_flexible_buffer(t, buf, size);
duke@435	111	}
duke@435	112
duke@435	113	jchar* as_unicode(int& length) const;
duke@435	114
duke@435	115	// Treating this symbol as a class name, returns the Java name for the class.
duke@435	116	// String is allocated in resource area if buffer is not provided.
duke@435	117	// See Klass::external_name()
duke@435	118	const char* as_klass_external_name() const;
duke@435	119	const char* as_klass_external_name(char* buf, int size) const;
duke@435	120
duke@435	121	bool object_is_parsable() const {
duke@435	122	return (utf8_length() > 0 || (oop)this == Universe::emptySymbol());
duke@435	123	}
duke@435	124
duke@435	125	// Printing
duke@435	126	void print_symbol_on(outputStream* st = NULL);
duke@435	127	};
duke@435	128
duke@435	129
duke@435	130	// Note: this comparison is used for vtable sorting only; it doesn't matter
duke@435	131	// what order it defines, as long as it is a total, time-invariant order
duke@435	132	// Since symbolOops are in permSpace, their relative order in memory never changes,
duke@435	133	// so use address comparison for speed
duke@435	134	int symbolOopDesc::fast_compare(symbolOop other) const {
duke@435	135	return (((uintptr_t)this < (uintptr_t)other) ? -1
duke@435	136	: ((uintptr_t)this == (uintptr_t) other) ? 0 : 1);
duke@435	137	}
stefank@2314	138
stefank@2314	139	#endif // SHARE_VM_OOPS_SYMBOLOOP_HPP