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src/share/vm/utilities/defaultStream.hpp@c96030fff130 (annotated)

src/share/vm/utilities/defaultStream.hpp

Thu, 20 Nov 2008 16:56:09 -0800

author

ysr

date

Thu, 20 Nov 2008 16:56:09 -0800

changeset 888

c96030fff130

parent 435

a61af66fc99e

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa

duke@435	1	/*
duke@435	2	* Copyright 2003-2004 Sun Microsystems, Inc. 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	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	class defaultStream : public xmlTextStream {
duke@435	26	friend void ostream_abort();
duke@435	27	public:
duke@435	28	enum { NO_WRITER = -1 };
duke@435	29	private:
duke@435	30	bool _inited;
duke@435	31	fileStream* _log_file; // XML-formatted file shared by all threads
duke@435	32	static int _output_fd;
duke@435	33	static int _error_fd;
duke@435	34	static FILE* _output_stream;
duke@435	35	static FILE* _error_stream;
duke@435	36
duke@435	37	void init();
duke@435	38	void init_log();
duke@435	39	void finish_log();
duke@435	40	void finish_log_on_error(char *buf, int buflen);
duke@435	41	public:
duke@435	42	// must defer time stamp due to the fact that os::init() hasn't
duke@435	43	// yet been called and os::elapsed_counter() may not be valid
duke@435	44	defaultStream() {
duke@435	45	_log_file = NULL;
duke@435	46	_inited = false;
duke@435	47	_writer = -1;
duke@435	48	_last_writer = -1;
duke@435	49	}
duke@435	50
duke@435	51	~defaultStream() {
duke@435	52	if (has_log_file()) finish_log();
duke@435	53	}
duke@435	54
duke@435	55	static inline FILE* output_stream() {
duke@435	56	return DisplayVMOutputToStderr ? _error_stream : _output_stream;
duke@435	57	}
duke@435	58	static inline FILE* error_stream() {
duke@435	59	return DisplayVMOutputToStdout ? _output_stream : _error_stream;
duke@435	60	}
duke@435	61	static inline int output_fd() {
duke@435	62	return DisplayVMOutputToStderr ? _error_fd : _output_fd;
duke@435	63	}
duke@435	64	static inline int error_fd() {
duke@435	65	return DisplayVMOutputToStdout ? _output_fd : _error_fd;
duke@435	66	}
duke@435	67
duke@435	68	virtual void write(const char* s, size_t len);
duke@435	69
duke@435	70	void flush() {
duke@435	71	// once we can determine whether we are in a signal handler, we
duke@435	72	// should add the following assert here:
duke@435	73	// assert(xxxxxx, "can not flush buffer inside signal handler");
duke@435	74	xmlTextStream::flush();
duke@435	75	fflush(output_stream());
duke@435	76	if (has_log_file()) _log_file->flush();
duke@435	77	}
duke@435	78
duke@435	79	// advisory lock/unlock of _writer field:
duke@435	80	private:
duke@435	81	intx _writer; // thread_id with current rights to output
duke@435	82	intx _last_writer;
duke@435	83	public:
duke@435	84	intx hold(intx writer_id);
duke@435	85	void release(intx holder);
duke@435	86	intx writer() { return _writer; }
duke@435	87	bool has_log_file();
duke@435	88
duke@435	89	static defaultStream* instance; // sole instance
duke@435	90	};