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