1 /*
   2  * Copyright (c) 1997, 2019, 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_UTILITIES_OSTREAM_HPP
  26 #define SHARE_UTILITIES_OSTREAM_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/timer.hpp"
  30 #include "utilities/globalDefinitions.hpp"
  31 
  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    char* _scratch;   // internal scratch buffer for printf
  53    size_t _scratch_len; // size of internal scratch buffer
  54 
  55    void update_position(const char* s, size_t len);
  56    static const char* do_vsnprintf(char* buffer, size_t buflen,
  57                                    const char* format, va_list ap,
  58                                    bool add_cr,
  59                                    size_t& result_len)  ATTRIBUTE_PRINTF(3, 0);
  60 
  61    // calls do_vsnprintf and writes output to stream; uses an on-stack buffer.
  62    void do_vsnprintf_and_write_with_automatic_buffer(const char* format, va_list ap, bool add_cr) ATTRIBUTE_PRINTF(2, 0);
  63    // calls do_vsnprintf and writes output to stream; uses the user-provided buffer;
  64    void do_vsnprintf_and_write_with_scratch_buffer(const char* format, va_list ap, bool add_cr) ATTRIBUTE_PRINTF(2, 0);
  65    // calls do_vsnprintf, then writes output to stream.
  66    void do_vsnprintf_and_write(const char* format, va_list ap, bool add_cr) ATTRIBUTE_PRINTF(2, 0);
  67 
  68  public:
  69    // creation
  70    outputStream(int width = 80);
  71    outputStream(int width, bool has_time_stamps);
  72 
  73    // indentation
  74    outputStream& indent();
  75    void inc() { _indentation++; };
  76    void dec() { _indentation--; };
  77    void inc(int n) { _indentation += n; };
  78    void dec(int n) { _indentation -= n; };
  79    int  indentation() const    { return _indentation; }
  80    void set_indentation(int i) { _indentation = i;    }
  81    void fill_to(int col);
  82    void move_to(int col, int slop = 6, int min_space = 2);
  83 
  84    // sizing
  85    int width()    const { return _width;    }
  86    int position() const { return _position; }
  87    int newlines() const { return _newlines; }
  88    julong count() const { return _precount + _position; }
  89    void set_count(julong count) { _precount = count - _position; }
  90    void set_position(int pos)   { _position = pos; }
  91 
  92    // printing
  93    void print(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
  94    void print_cr(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
  95    void vprint(const char *format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
  96    void vprint_cr(const char* format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
  97    void print_raw(const char* str)            { write(str, strlen(str)); }
  98    void print_raw(const char* str, int len)   { write(str,         len); }
  99    void print_raw_cr(const char* str)         { write(str, strlen(str)); cr(); }
 100    void print_raw_cr(const char* str, int len){ write(str,         len); cr(); }
 101    void print_data(void* data, size_t len, bool with_ascii);
 102    void put(char ch);
 103    void sp(int count = 1);
 104    void cr();
 105    void cr_indent();
 106    void bol() { if (_position > 0)  cr(); }
 107 
 108 
 109    // Time stamp
 110    TimeStamp& time_stamp() { return _stamp; }
 111    void stamp();
 112    void stamp(bool guard, const char* prefix, const char* suffix);
 113    void stamp(bool guard) {
 114      stamp(guard, "", ": ");
 115    }
 116    // Date stamp
 117    void date_stamp(bool guard, const char* prefix, const char* suffix);
 118    // A simplified call that includes a suffix of ": "
 119    void date_stamp(bool guard) {
 120      date_stamp(guard, "", ": ");
 121    }
 122 
 123    // portable printing of 64 bit integers
 124    void print_jlong(jlong value);
 125    void print_julong(julong value);
 126 
 127    // flushing
 128    virtual void flush() {}
 129    virtual void write(const char* str, size_t len) = 0;
 130    virtual void rotate_log(bool force, outputStream* out = NULL) {} // GC log rotation
 131    virtual ~outputStream() {}   // close properly on deletion
 132 
 133    // Caller may specify their own scratch buffer to use for printing; otherwise,
 134    // an automatic buffer on the stack (with O_BUFLEN len) is used.
 135    void set_scratch_buffer(char* p, size_t len) { _scratch = p; _scratch_len = len; }
 136 
 137    void dec_cr() { dec(); cr(); }
 138    void inc_cr() { inc(); cr(); }
 139 };
 140 
 141 // standard output
 142 // ANSI C++ name collision
 143 extern outputStream* tty;           // tty output
 144 
 145 class streamIndentor : public StackObj {
 146  private:
 147   outputStream* _str;
 148   int _amount;
 149 
 150  public:
 151   streamIndentor(outputStream* str, int amt = 2) : _str(str), _amount(amt) {
 152     _str->inc(_amount);
 153   }
 154   ~streamIndentor() { _str->dec(_amount); }
 155 };
 156 
 157 // advisory locking for the shared tty stream:
 158 class ttyLocker: StackObj {
 159   friend class ttyUnlocker;
 160  private:
 161   intx _holder;
 162 
 163  public:
 164   static intx  hold_tty();                // returns a "holder" token
 165   static void  release_tty(intx holder);  // must witness same token
 166   static bool  release_tty_if_locked();   // returns true if lock was released
 167   static void  break_tty_lock_for_safepoint(intx holder);
 168 
 169   ttyLocker()  { _holder = hold_tty(); }
 170   ~ttyLocker() { release_tty(_holder); }
 171 };
 172 
 173 // Release the tty lock if it's held and reacquire it if it was
 174 // locked.  Used to avoid lock ordering problems.
 175 class ttyUnlocker: StackObj {
 176  private:
 177   bool _was_locked;
 178  public:
 179   ttyUnlocker()  {
 180     _was_locked = ttyLocker::release_tty_if_locked();
 181   }
 182   ~ttyUnlocker() {
 183     if (_was_locked) {
 184       ttyLocker::hold_tty();
 185     }
 186   }
 187 };
 188 
 189 // for writing to strings; buffer will expand automatically
 190 class stringStream : public outputStream {
 191  protected:
 192   char*  buffer;
 193   size_t buffer_pos;
 194   size_t buffer_length;
 195   bool   buffer_fixed;
 196   DEBUG_ONLY(ResourceMark* rm;)
 197  public:
 198   stringStream(size_t initial_bufsize = 256);
 199   stringStream(char* fixed_buffer, size_t fixed_buffer_size);
 200   ~stringStream();
 201   virtual void write(const char* c, size_t len);
 202   size_t      size() { return buffer_pos; }
 203   const char* base() { return buffer; }
 204   void  reset() { buffer_pos = 0; _precount = 0; _position = 0; }
 205   char* as_string();
 206 };
 207 
 208 class fileStream : public outputStream {
 209  protected:
 210   FILE* _file;
 211   bool  _need_close;
 212  public:
 213   fileStream() { _file = NULL; _need_close = false; }
 214   fileStream(const char* file_name);
 215   fileStream(const char* file_name, const char* opentype);
 216   fileStream(FILE* file, bool need_close = false) { _file = file; _need_close = need_close; }
 217   ~fileStream();
 218   bool is_open() const { return _file != NULL; }
 219   virtual void write(const char* c, size_t len);
 220   size_t read(void *data, size_t size, size_t count) { return ::fread(data, size, count, _file); }
 221   char* readln(char *data, int count);
 222   int eof() { return feof(_file); }
 223   long fileSize();
 224   void rewind() { ::rewind(_file); }
 225   void flush();
 226 };
 227 
 228 CDS_ONLY(extern fileStream*   classlist_file;)
 229 
 230 // unlike fileStream, fdStream does unbuffered I/O by calling
 231 // open() and write() directly. It is async-safe, but output
 232 // from multiple thread may be mixed together. Used by fatal
 233 // error handler.
 234 class fdStream : public outputStream {
 235  protected:
 236   int  _fd;
 237  public:
 238   fdStream(int fd = -1) : _fd(fd) { }
 239   bool is_open() const { return _fd != -1; }
 240   void set_fd(int fd) { _fd = fd; }
 241   int fd() const { return _fd; }
 242   virtual void write(const char* c, size_t len);
 243   void flush() {};
 244 };
 245 
 246 void ostream_init();
 247 void ostream_init_log();
 248 void ostream_exit();
 249 void ostream_abort();
 250 
 251 // In the non-fixed buffer case an underlying buffer will be created and
 252 // managed in C heap. Not MT-safe.
 253 class bufferedStream : public outputStream {
 254  protected:
 255   char*  buffer;
 256   size_t buffer_pos;
 257   size_t buffer_max;
 258   size_t buffer_length;
 259   bool   buffer_fixed;
 260  public:
 261   bufferedStream(size_t initial_bufsize = 256, size_t bufmax = 1024*1024*10);
 262   bufferedStream(char* fixed_buffer, size_t fixed_buffer_size, size_t bufmax = 1024*1024*10);
 263   ~bufferedStream();
 264   virtual void write(const char* c, size_t len);
 265   size_t      size() { return buffer_pos; }
 266   const char* base() { return buffer; }
 267   void  reset() { buffer_pos = 0; _precount = 0; _position = 0; }
 268   char* as_string();
 269 };
 270 
 271 #define O_BUFLEN 20000   // max size of output of individual print() methods
 272 
 273 #ifndef PRODUCT
 274 
 275 class networkStream : public bufferedStream {
 276 
 277   private:
 278     int _socket;
 279 
 280   public:
 281     networkStream();
 282     ~networkStream();
 283 
 284     bool connect(const char *host, short port);
 285     bool is_open() const { return _socket != -1; }
 286     int read(char *buf, size_t len);
 287     void close();
 288     virtual void flush();
 289 };
 290 
 291 #endif
 292 
 293 #endif // SHARE_UTILITIES_OSTREAM_HPP