1 /*
   2  * Copyright (c) 1997, 2014, 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_OSTREAM_HPP
  26 #define SHARE_VM_UTILITIES_OSTREAM_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/timer.hpp"
  30 
  31 class GCId;
  32 DEBUG_ONLY(class ResourceMark;)
  33 
  34 // Output streams for printing
  35 //
  36 // Printing guidelines:
  37 // Where possible, please use tty->print() and tty->print_cr().
  38 // For product mode VM warnings use warning() which internally uses tty.
  39 // In places where tty is not initialized yet or too much overhead,
  40 // we may use jio_printf:
  41 //     jio_fprintf(defaultStream::output_stream(), "Message");
  42 // This allows for redirection via -XX:+DisplayVMOutputToStdout and
  43 // -XX:+DisplayVMOutputToStderr
  44 class outputStream : public ResourceObj {
  45  protected:
  46    int _indentation; // current indentation
  47    int _width;       // width of the page
  48    int _position;    // position on the current line
  49    int _newlines;    // number of '\n' output so far
  50    julong _precount; // number of chars output, less _position
  51    TimeStamp _stamp; // for time stamps
  52 
  53    void update_position(const char* s, size_t len);
  54    static const char* do_vsnprintf(char* buffer, size_t buflen,
  55                                    const char* format, va_list ap,
  56                                    bool add_cr,
  57                                    size_t& result_len)  ATTRIBUTE_PRINTF(3, 0);
  58 
  59  public:
  60    // creation
  61    outputStream(int width = 80);
  62    outputStream(int width, bool has_time_stamps);
  63 
  64    // indentation
  65    outputStream& indent();
  66    void inc() { _indentation++; };
  67    void dec() { _indentation--; };
  68    void inc(int n) { _indentation += n; };
  69    void dec(int n) { _indentation -= n; };
  70    int  indentation() const    { return _indentation; }
  71    void set_indentation(int i) { _indentation = i;    }
  72    void fill_to(int col);
  73    void move_to(int col, int slop = 6, int min_space = 2);
  74 
  75    // sizing
  76    int width()    const { return _width;    }
  77    int position() const { return _position; }
  78    int newlines() const { return _newlines; }
  79    julong count() const { return _precount + _position; }
  80    void set_count(julong count) { _precount = count - _position; }
  81    void set_position(int pos)   { _position = pos; }
  82 
  83    // printing
  84    void print(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
  85    void print_cr(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
  86    void vprint(const char *format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
  87    void vprint_cr(const char* format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
  88    void print_raw(const char* str)            { write(str, strlen(str)); }
  89    void print_raw(const char* str, int len)   { write(str,         len); }
  90    void print_raw_cr(const char* str)         { write(str, strlen(str)); cr(); }
  91    void print_raw_cr(const char* str, int len){ write(str,         len); cr(); }
  92    void print_data(void* data, size_t len, bool with_ascii);
  93    void put(char ch);
  94    void sp(int count = 1);
  95    void cr();
  96    void bol() { if (_position > 0)  cr(); }
  97 
  98    // Time stamp
  99    TimeStamp& time_stamp() { return _stamp; }
 100    void stamp();
 101    void stamp(bool guard, const char* prefix, const char* suffix);
 102    void stamp(bool guard) {
 103      stamp(guard, "", ": ");
 104    }
 105    // Date stamp
 106    void date_stamp(bool guard, const char* prefix, const char* suffix);
 107    // A simplified call that includes a suffix of ": "
 108    void date_stamp(bool guard) {
 109      date_stamp(guard, "", ": ");
 110    }
 111    void gclog_stamp(const GCId& gc_id);
 112 
 113    // portable printing of 64 bit integers
 114    void print_jlong(jlong value);
 115    void print_julong(julong value);
 116 
 117    // flushing
 118    virtual void flush() {}
 119    virtual void write(const char* str, size_t len) = 0;
 120    virtual void rotate_log(bool force, outputStream* out = NULL) {} // GC log rotation
 121    virtual ~outputStream() {}   // close properly on deletion
 122 
 123    void dec_cr() { dec(); cr(); }
 124    void inc_cr() { inc(); cr(); }
 125 };
 126 
 127 // standard output
 128 // ANSI C++ name collision
 129 extern outputStream* tty;           // tty output
 130 extern outputStream* gclog_or_tty;  // stream for gc log if -Xloggc:<f>, or tty
 131 
 132 class streamIndentor : public StackObj {
 133  private:
 134   outputStream* _str;
 135   int _amount;
 136 
 137  public:
 138   streamIndentor(outputStream* str, int amt = 2) : _str(str), _amount(amt) {
 139     _str->inc(_amount);
 140   }
 141   ~streamIndentor() { _str->dec(_amount); }
 142 };
 143 
 144 
 145 // advisory locking for the shared tty stream:
 146 class ttyLocker: StackObj {
 147   friend class ttyUnlocker;
 148  private:
 149   intx _holder;
 150 
 151  public:
 152   static intx  hold_tty();                // returns a "holder" token
 153   static void  release_tty(intx holder);  // must witness same token
 154   static bool  release_tty_if_locked();   // returns true if lock was released
 155   static void  break_tty_lock_for_safepoint(intx holder);
 156 
 157   ttyLocker()  { _holder = hold_tty(); }
 158   ~ttyLocker() { release_tty(_holder); }
 159 };
 160 
 161 // Release the tty lock if it's held and reacquire it if it was
 162 // locked.  Used to avoid lock ordering problems.
 163 class ttyUnlocker: StackObj {
 164  private:
 165   bool _was_locked;
 166  public:
 167   ttyUnlocker()  {
 168     _was_locked = ttyLocker::release_tty_if_locked();
 169   }
 170   ~ttyUnlocker() {
 171     if (_was_locked) {
 172       ttyLocker::hold_tty();
 173     }
 174   }
 175 };
 176 
 177 // for writing to strings; buffer will expand automatically
 178 class stringStream : public outputStream {
 179  protected:
 180   char*  buffer;
 181   size_t buffer_pos;
 182   size_t buffer_length;
 183   bool   buffer_fixed;
 184   DEBUG_ONLY(ResourceMark* rm;)
 185  public:
 186   stringStream(size_t initial_bufsize = 256);
 187   stringStream(char* fixed_buffer, size_t fixed_buffer_size);
 188   ~stringStream();
 189   virtual void write(const char* c, size_t len);
 190   size_t      size() { return buffer_pos; }
 191   const char* base() { return buffer; }
 192   void  reset() { buffer_pos = 0; _precount = 0; _position = 0; }
 193   char* as_string();
 194 };
 195 
 196 class fileStream : public outputStream {
 197  protected:
 198   FILE* _file;
 199   bool  _need_close;
 200  public:
 201   fileStream() { _file = NULL; _need_close = false; }
 202   fileStream(const char* file_name);
 203   fileStream(const char* file_name, const char* opentype);
 204   fileStream(FILE* file, bool need_close = false) { _file = file; _need_close = need_close; }
 205   ~fileStream();
 206   bool is_open() const { return _file != NULL; }
 207   void set_need_close(bool b) { _need_close = b;}
 208   virtual void write(const char* c, size_t len);
 209   size_t read(void *data, size_t size, size_t count) { return ::fread(data, size, count, _file); }
 210   char* readln(char *data, int count);
 211   int eof() { return feof(_file); }
 212   long fileSize();
 213   void rewind() { ::rewind(_file); }
 214   void flush();
 215 };
 216 
 217 CDS_ONLY(extern fileStream*   classlist_file;)
 218 
 219 // unlike fileStream, fdStream does unbuffered I/O by calling
 220 // open() and write() directly. It is async-safe, but output
 221 // from multiple thread may be mixed together. Used by fatal
 222 // error handler.
 223 class fdStream : public outputStream {
 224  protected:
 225   int  _fd;
 226   bool _need_close;
 227  public:
 228   fdStream(const char* file_name);
 229   fdStream(int fd = -1) { _fd = fd; _need_close = false; }
 230   ~fdStream();
 231   bool is_open() const { return _fd != -1; }
 232   void set_fd(int fd) { _fd = fd; _need_close = false; }
 233   int fd() const { return _fd; }
 234   virtual void write(const char* c, size_t len);
 235   void flush() {};
 236 };
 237 
 238 class gcLogFileStream : public fileStream {
 239  protected:
 240   const char*  _file_name;
 241   jlong  _bytes_written;
 242   uintx  _cur_file_num;             // current logfile rotation number, from 0 to NumberOfGCLogFiles-1
 243  public:
 244   gcLogFileStream(const char* file_name);
 245   ~gcLogFileStream();
 246   virtual void write(const char* c, size_t len);
 247   virtual void rotate_log(bool force, outputStream* out = NULL);
 248   void dump_loggc_header();
 249 
 250   /* If "force" sets true, force log file rotation from outside JVM */
 251   bool should_rotate(bool force) {
 252     return force ||
 253              ((GCLogFileSize != 0) && ((uintx)_bytes_written >= GCLogFileSize));
 254   }
 255 
 256 };
 257 
 258 #ifndef PRODUCT
 259 // unit test for checking -Xloggc:<filename> parsing result
 260 void test_loggc_filename();
 261 void test_snprintf();
 262 #endif
 263 
 264 void ostream_init();
 265 void ostream_init_log();
 266 void ostream_exit();
 267 void ostream_abort();
 268 
 269 // staticBufferStream uses a user-supplied buffer for all formatting.
 270 // Used for safe formatting during fatal error handling.  Not MT safe.
 271 // Do not share the stream between multiple threads.
 272 class staticBufferStream : public outputStream {
 273  private:
 274   char* _buffer;
 275   size_t _buflen;
 276   outputStream* _outer_stream;
 277  public:
 278   staticBufferStream(char* buffer, size_t buflen,
 279                      outputStream *outer_stream);
 280   ~staticBufferStream() {};
 281   virtual void write(const char* c, size_t len);
 282   void flush();
 283   void print(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
 284   void print_cr(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
 285   void vprint(const char *format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
 286   void vprint_cr(const char* format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
 287 };
 288 
 289 // In the non-fixed buffer case an underlying buffer will be created and
 290 // managed in C heap. Not MT-safe.
 291 class bufferedStream : public outputStream {
 292  protected:
 293   char*  buffer;
 294   size_t buffer_pos;
 295   size_t buffer_max;
 296   size_t buffer_length;
 297   bool   buffer_fixed;
 298  public:
 299   bufferedStream(size_t initial_bufsize = 256, size_t bufmax = 1024*1024*10);
 300   bufferedStream(char* fixed_buffer, size_t fixed_buffer_size, size_t bufmax = 1024*1024*10);
 301   ~bufferedStream();
 302   virtual void write(const char* c, size_t len);
 303   size_t      size() { return buffer_pos; }
 304   const char* base() { return buffer; }
 305   void  reset() { buffer_pos = 0; _precount = 0; _position = 0; }
 306   char* as_string();
 307 };
 308 
 309 #define O_BUFLEN 2000   // max size of output of individual print() methods
 310 
 311 #ifndef PRODUCT
 312 
 313 class networkStream : public bufferedStream {
 314 
 315   private:
 316     int _socket;
 317 
 318   public:
 319     networkStream();
 320     ~networkStream();
 321 
 322     bool connect(const char *host, short port);
 323     bool is_open() const { return _socket != -1; }
 324     int read(char *buf, size_t len);
 325     void close();
 326     virtual void flush();
 327 };
 328 
 329 #endif
 330 
 331 #endif // SHARE_VM_UTILITIES_OSTREAM_HPP