jdk8-mips64-public/hotspot: src/share/vm/utilities/defaultStream.hpp@c96030fff130

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

     1 /*

     2  * Copyright 2003-2004 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    25 class defaultStream : public xmlTextStream {

    26   friend void ostream_abort();

    27  public:

    28   enum { NO_WRITER = -1 };

    29  private:

    30   bool         _inited;

    31   fileStream*  _log_file;  // XML-formatted file shared by all threads

    32   static int   _output_fd;

    33   static int   _error_fd;

    34   static FILE* _output_stream;

    35   static FILE* _error_stream;

    37   void init();

    38   void init_log();

    39   void finish_log();

    40   void finish_log_on_error(char *buf, int buflen);

    41  public:

    42   // must defer time stamp due to the fact that os::init() hasn't

    43   // yet been called and os::elapsed_counter() may not be valid

    44   defaultStream() {

    45     _log_file = NULL;

    46     _inited = false;

    47     _writer = -1;

    48     _last_writer = -1;

    49   }

    51   ~defaultStream() {

    52     if (has_log_file())  finish_log();

    53   }

    55   static inline FILE* output_stream() {

    56     return DisplayVMOutputToStderr ? _error_stream : _output_stream;

    57   }

    58   static inline FILE* error_stream() {

    59     return DisplayVMOutputToStdout ? _output_stream : _error_stream;

    60   }

    61   static inline int output_fd() {

    62     return DisplayVMOutputToStderr ? _error_fd : _output_fd;

    63   }

    64   static inline int error_fd() {

    65     return DisplayVMOutputToStdout ? _output_fd : _error_fd;

    66   }

    68   virtual void write(const char* s, size_t len);

    70   void flush() {

    71     // once we can determine whether we are in a signal handler, we

    72     // should add the following assert here:

    73     // assert(xxxxxx, "can not flush buffer inside signal handler");

    74     xmlTextStream::flush();

    75     fflush(output_stream());

    76     if (has_log_file()) _log_file->flush();

    77   }

    79   // advisory lock/unlock of _writer field:

    80  private:

    81   intx _writer;    // thread_id with current rights to output

    82   intx _last_writer;

    83  public:

    84   intx hold(intx writer_id);

    85   void release(intx holder);

    86   intx writer() { return _writer; }

    87   bool has_log_file();

    89   static defaultStream* instance;  // sole instance

    90 };

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

src/share/vm/utilities/defaultStream.hpp@c96030fff130

src/share/vm/utilities/defaultStream.hpp