1 /*
   2  * Copyright (c) 1997, 2020, 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  private:
  46    NONCOPYABLE(outputStream);
  47 
  48  protected:
  49    int _indentation; // current indentation
  50    int _width;       // width of the page
  51    int _position;    // position on the current line
  52    int _newlines;    // number of '\n' output so far
  53    julong _precount; // number of chars output, less _position
  54    TimeStamp _stamp; // for time stamps
  55    char* _scratch;   // internal scratch buffer for printf
  56    size_t _scratch_len; // size of internal scratch buffer
  57 
  58    void update_position(const char* s, size_t len);
  59    static const char* do_vsnprintf(char* buffer, size_t buflen,
  60                                    const char* format, va_list ap,
  61                                    bool add_cr,
  62                                    size_t& result_len)  ATTRIBUTE_PRINTF(3, 0);
  63 
  64    // calls do_vsnprintf and writes output to stream; uses an on-stack buffer.
  65    void do_vsnprintf_and_write_with_automatic_buffer(const char* format, va_list ap, bool add_cr) ATTRIBUTE_PRINTF(2, 0);
  66    // calls do_vsnprintf and writes output to stream; uses the user-provided buffer;
  67    void do_vsnprintf_and_write_with_scratch_buffer(const char* format, va_list ap, bool add_cr) ATTRIBUTE_PRINTF(2, 0);
  68    // calls do_vsnprintf, then writes output to stream.
  69    void do_vsnprintf_and_write(const char* format, va_list ap, bool add_cr) ATTRIBUTE_PRINTF(2, 0);
  70 
  71  public:
  72    // creation
  73    outputStream(int width = 80);
  74    outputStream(int width, bool has_time_stamps);
  75 
  76    // indentation
  77    outputStream& indent();
  78    void inc() { _indentation++; };
  79    void dec() { _indentation--; };
  80    void inc(int n) { _indentation += n; };
  81    void dec(int n) { _indentation -= n; };
  82    int  indentation() const    { return _indentation; }
  83    void set_indentation(int i) { _indentation = i;    }
  84    void fill_to(int col);
  85    void move_to(int col, int slop = 6, int min_space = 2);
  86 
  87    // sizing
  88    int width()    const { return _width;    }
  89    int position() const { return _position; }
  90    int newlines() const { return _newlines; }
  91    julong count() const { return _precount + _position; }
  92    void set_count(julong count) { _precount = count - _position; }
  93    void set_position(int pos)   { _position = pos; }
  94 
  95    // printing
  96    void print(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
  97    void print_cr(const char* format, ...) ATTRIBUTE_PRINTF(2, 3);
  98    void vprint(const char *format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
  99    void vprint_cr(const char* format, va_list argptr) ATTRIBUTE_PRINTF(2, 0);
 100    void print_raw(const char* str)            { write(str, strlen(str)); }
 101    void print_raw(const char* str, int len)   { write(str,         len); }
 102    void print_raw_cr(const char* str)         { write(str, strlen(str)); cr(); }
 103    void print_raw_cr(const char* str, int len){ write(str,         len); cr(); }
 104    void print_data(void* data, size_t len, bool with_ascii);
 105    void put(char ch);
 106    void sp(int count = 1);
 107    void cr();
 108    void cr_indent();
 109    void bol() { if (_position > 0)  cr(); }
 110 
 111 
 112    // Time stamp
 113    TimeStamp& time_stamp() { return _stamp; }
 114    void stamp();
 115    void stamp(bool guard, const char* prefix, const char* suffix);
 116    void stamp(bool guard) {
 117      stamp(guard, "", ": ");
 118    }
 119    // Date stamp
 120    void date_stamp(bool guard, const char* prefix, const char* suffix);
 121    // A simplified call that includes a suffix of ": "
 122    void date_stamp(bool guard) {
 123      date_stamp(guard, "", ": ");
 124    }
 125 
 126    // portable printing of 64 bit integers
 127    void print_jlong(jlong value);
 128    void print_julong(julong value);
 129 
 130    // flushing
 131    virtual void flush() {}
 132    virtual void write(const char* str, size_t len) = 0;
 133    virtual void rotate_log(bool force, outputStream* out = NULL) {} // GC log rotation
 134    virtual ~outputStream() {}   // close properly on deletion
 135 
 136    // Caller may specify their own scratch buffer to use for printing; otherwise,
 137    // an automatic buffer on the stack (with O_BUFLEN len) is used.
 138    void set_scratch_buffer(char* p, size_t len) { _scratch = p; _scratch_len = len; }
 139 
 140    void dec_cr() { dec(); cr(); }
 141    void inc_cr() { inc(); cr(); }
 142 };
 143 
 144 // standard output
 145 // ANSI C++ name collision
 146 extern outputStream* tty;           // tty output
 147 
 148 class streamIndentor : public StackObj {
 149  private:
 150   outputStream* _str;
 151   int _amount;
 152 
 153  public:
 154   streamIndentor(outputStream* str, int amt = 2) : _str(str), _amount(amt) {
 155     _str->inc(_amount);
 156   }
 157   ~streamIndentor() { _str->dec(_amount); }
 158 };
 159 
 160 // advisory locking for the shared tty stream:
 161 class ttyLocker: StackObj {
 162   friend class ttyUnlocker;
 163  private:
 164   intx _holder;
 165 
 166  public:
 167   static intx  hold_tty();                // returns a "holder" token
 168   static void  release_tty(intx holder);  // must witness same token
 169   static bool  release_tty_if_locked();   // returns true if lock was released
 170   static void  break_tty_lock_for_safepoint(intx holder);
 171 
 172   ttyLocker()  { _holder = hold_tty(); }
 173   ~ttyLocker() { release_tty(_holder); }
 174 };
 175 
 176 // Release the tty lock if it's held and reacquire it if it was
 177 // locked.  Used to avoid lock ordering problems.
 178 class ttyUnlocker: StackObj {
 179  private:
 180   bool _was_locked;
 181  public:
 182   ttyUnlocker()  {
 183     _was_locked = ttyLocker::release_tty_if_locked();
 184   }
 185   ~ttyUnlocker() {
 186     if (_was_locked) {
 187       ttyLocker::hold_tty();
 188     }
 189   }
 190 };
 191 
 192 // for writing to strings; buffer will expand automatically.
 193 // Buffer will always be zero-terminated.
 194 class stringStream : public outputStream {
 195  protected:
 196   char*  buffer;
 197   size_t buffer_pos;
 198   size_t buffer_length;
 199   bool   buffer_fixed;
 200 
 201   // zero terminate at buffer_pos.
 202   void zero_terminate();
 203 
 204  public:
 205   // Create a stringStream using an internal buffer of initially initial_bufsize size;
 206   // will be enlarged on demand. There is no maximum cap.
 207   stringStream(size_t initial_bufsize = 256);
 208   // Creates a stringStream using a caller-provided buffer. Will truncate silently if
 209   // it overflows.
 210   stringStream(char* fixed_buffer, size_t fixed_buffer_size);
 211   ~stringStream();
 212   virtual void write(const char* c, size_t len);
 213   // Return number of characters written into buffer, excluding terminating zero and
 214   // subject to truncation in static buffer mode.
 215   size_t      size() const { return buffer_pos; }
 216   const char* base() const { return buffer; }
 217   void  reset();
 218   // copy to a resource, or C-heap, array as requested
 219   char* as_string(bool c_heap = false) 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