1 /*
   2  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_UTILITIES_DEFAULTSTREAM_HPP
  26 #define SHARE_VM_UTILITIES_DEFAULTSTREAM_HPP
  27 
  28 #include "utilities/xmlstream.hpp"
  29 
  30 class defaultStream : public xmlTextStream {
  31   friend void ostream_abort();
  32  public:
  33   enum { NO_WRITER = -1 };
  34  private:
  35   bool         _inited;
  36   fileStream*  _log_file;  // XML-formatted file shared by all threads
  37   static int   _output_fd;
  38   static int   _error_fd;
  39   static FILE* _output_stream;
  40   static FILE* _error_stream;
  41 
  42   void init();
  43   void init_log();
  44   void finish_log();
  45   void finish_log_on_error(char *buf, int buflen);
  46  public:
  47   // must defer time stamp due to the fact that os::init() hasn't
  48   // yet been called and os::elapsed_counter() may not be valid
  49   defaultStream() {
  50     _log_file = NULL;
  51     _inited = false;
  52     _writer = -1;
  53     _last_writer = -1;
  54   }
  55 
  56   ~defaultStream() {
  57     if (has_log_file())  finish_log();
  58   }
  59 
  60   static inline FILE* output_stream() {
  61     return DisplayVMOutputToStderr ? _error_stream : _output_stream;
  62   }
  63   static inline FILE* error_stream() {
  64     return DisplayVMOutputToStdout ? _output_stream : _error_stream;
  65   }
  66   static inline int output_fd() {
  67     return DisplayVMOutputToStderr ? _error_fd : _output_fd;
  68   }
  69   static inline int error_fd() {
  70     return DisplayVMOutputToStdout ? _output_fd : _error_fd;
  71   }
  72 
  73   virtual void write(const char* s, size_t len);
  74 
  75   void flush() {
  76     // once we can determine whether we are in a signal handler, we
  77     // should add the following assert here:
  78     // assert(xxxxxx, "can not flush buffer inside signal handler");
  79     xmlTextStream::flush();
  80     fflush(output_stream());
  81     if (has_log_file()) _log_file->flush();
  82   }
  83 
  84   // advisory lock/unlock of _writer field:
  85  private:
  86   intx _writer;    // thread_id with current rights to output
  87   intx _last_writer;
  88  public:
  89   intx hold(intx writer_id);
  90   void release(intx holder);
  91   intx writer() { return _writer; }
  92   bool has_log_file();
  93 
  94   static defaultStream* instance;  // sole instance
  95 };
  96 
  97 #endif // SHARE_VM_UTILITIES_DEFAULTSTREAM_HPP