view src/share/vm/utilities/ostream.cpp @ 6862:8a5ea0a9ccc4

7127708: G1: change task num types from int to uint in concurrent mark Summary: Change the type of various task num fields, parameters etc to unsigned and rename them to be more consistent with the other collectors. Code changes were also reviewed by Vitaly Davidovich. Reviewed-by: johnc Contributed-by: Kaushik Srenevasan <kaushik@twitter.com>
author johnc
date Sat, 06 Oct 2012 01:17:44 -0700
parents 4ee06e614636
children c38f13903fdf c3e799c37717
line wrap: on
line source

/*
 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "compiler/compileLog.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/arguments.hpp"
#include "utilities/defaultStream.hpp"
#include "utilities/ostream.hpp"
#include "utilities/top.hpp"
#include "utilities/xmlstream.hpp"
#ifdef TARGET_OS_FAMILY_linux
# include "os_linux.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_solaris
# include "os_solaris.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_windows
# include "os_windows.inline.hpp"
#endif
#ifdef TARGET_OS_FAMILY_bsd
# include "os_bsd.inline.hpp"
#endif

extern "C" void jio_print(const char* s); // Declarationtion of jvm method

outputStream::outputStream(int width) {
  _width       = width;
  _position    = 0;
  _newlines    = 0;
  _precount    = 0;
  _indentation = 0;
}

outputStream::outputStream(int width, bool has_time_stamps) {
  _width       = width;
  _position    = 0;
  _newlines    = 0;
  _precount    = 0;
  _indentation = 0;
  if (has_time_stamps)  _stamp.update();
}

void outputStream::update_position(const char* s, size_t len) {
  for (size_t i = 0; i < len; i++) {
    char ch = s[i];
    if (ch == '\n') {
      _newlines += 1;
      _precount += _position + 1;
      _position = 0;
    } else if (ch == '\t') {
      int tw = 8 - (_position & 7);
      _position += tw;
      _precount -= tw-1;  // invariant:  _precount + _position == total count
    } else {
      _position += 1;
    }
  }
}

// Execute a vsprintf, using the given buffer if necessary.
// Return a pointer to the formatted string.
const char* outputStream::do_vsnprintf(char* buffer, size_t buflen,
                                       const char* format, va_list ap,
                                       bool add_cr,
                                       size_t& result_len) {
  const char* result;
  if (add_cr)  buflen--;
  if (!strchr(format, '%')) {
    // constant format string
    result = format;
    result_len = strlen(result);
    if (add_cr && result_len >= buflen)  result_len = buflen-1;  // truncate
  } else if (format[0] == '%' && format[1] == 's' && format[2] == '\0') {
    // trivial copy-through format string
    result = va_arg(ap, const char*);
    result_len = strlen(result);
    if (add_cr && result_len >= buflen)  result_len = buflen-1;  // truncate
  } else if (vsnprintf(buffer, buflen, format, ap) >= 0) {
    result = buffer;
    result_len = strlen(result);
  } else {
    DEBUG_ONLY(warning("increase O_BUFLEN in ostream.hpp -- output truncated");)
    result = buffer;
    result_len = buflen - 1;
    buffer[result_len] = 0;
  }
  if (add_cr) {
    if (result != buffer) {
      strncpy(buffer, result, buflen);
      result = buffer;
    }
    buffer[result_len++] = '\n';
    buffer[result_len] = 0;
  }
  return result;
}

void outputStream::print(const char* format, ...) {
  char buffer[O_BUFLEN];
  va_list ap;
  va_start(ap, format);
  size_t len;
  const char* str = do_vsnprintf(buffer, O_BUFLEN, format, ap, false, len);
  write(str, len);
  va_end(ap);
}

void outputStream::print_cr(const char* format, ...) {
  char buffer[O_BUFLEN];
  va_list ap;
  va_start(ap, format);
  size_t len;
  const char* str = do_vsnprintf(buffer, O_BUFLEN, format, ap, true, len);
  write(str, len);
  va_end(ap);
}

void outputStream::vprint(const char *format, va_list argptr) {
  char buffer[O_BUFLEN];
  size_t len;
  const char* str = do_vsnprintf(buffer, O_BUFLEN, format, argptr, false, len);
  write(str, len);
}

void outputStream::vprint_cr(const char* format, va_list argptr) {
  char buffer[O_BUFLEN];
  size_t len;
  const char* str = do_vsnprintf(buffer, O_BUFLEN, format, argptr, true, len);
  write(str, len);
}

void outputStream::fill_to(int col) {
  int need_fill = col - position();
  sp(need_fill);
}

void outputStream::move_to(int col, int slop, int min_space) {
  if (position() >= col + slop)
    cr();
  int need_fill = col - position();
  if (need_fill < min_space)
    need_fill = min_space;
  sp(need_fill);
}

void outputStream::put(char ch) {
  assert(ch != 0, "please fix call site");
  char buf[] = { ch, '\0' };
  write(buf, 1);
}

#define SP_USE_TABS false

void outputStream::sp(int count) {
  if (count < 0)  return;
  if (SP_USE_TABS && count >= 8) {
    int target = position() + count;
    while (count >= 8) {
      this->write("\t", 1);
      count -= 8;
    }
    count = target - position();
  }
  while (count > 0) {
    int nw = (count > 8) ? 8 : count;
    this->write("        ", nw);
    count -= nw;
  }
}

void outputStream::cr() {
  this->write("\n", 1);
}

void outputStream::stamp() {
  if (! _stamp.is_updated()) {
    _stamp.update(); // start at 0 on first call to stamp()
  }

  // outputStream::stamp() may get called by ostream_abort(), use snprintf
  // to avoid allocating large stack buffer in print().
  char buf[40];
  jio_snprintf(buf, sizeof(buf), "%.3f", _stamp.seconds());
  print_raw(buf);
}

void outputStream::stamp(bool guard,
                         const char* prefix,
                         const char* suffix) {
  if (!guard) {
    return;
  }
  print_raw(prefix);
  stamp();
  print_raw(suffix);
}

void outputStream::date_stamp(bool guard,
                              const char* prefix,
                              const char* suffix) {
  if (!guard) {
    return;
  }
  print_raw(prefix);
  static const char error_time[] = "yyyy-mm-ddThh:mm:ss.mmm+zzzz";
  static const int buffer_length = 32;
  char buffer[buffer_length];
  const char* iso8601_result = os::iso8601_time(buffer, buffer_length);
  if (iso8601_result != NULL) {
    print_raw(buffer);
  } else {
    print_raw(error_time);
  }
  print_raw(suffix);
  return;
}

outputStream& outputStream::indent() {
  while (_position < _indentation) sp();
  return *this;
}

void outputStream::print_jlong(jlong value) {
  // N.B. Same as INT64_FORMAT
  print(os::jlong_format_specifier(), value);
}

void outputStream::print_julong(julong value) {
  // N.B. Same as UINT64_FORMAT
  print(os::julong_format_specifier(), value);
}

/**
 * This prints out hex data in a 'windbg' or 'xxd' form, where each line is:
 *   <hex-address>: 8 * <hex-halfword> <ascii translation (optional)>
 * example:
 * 0000000: 7f44 4f46 0102 0102 0000 0000 0000 0000  .DOF............
 * 0000010: 0000 0000 0000 0040 0000 0020 0000 0005  .......@... ....
 * 0000020: 0000 0000 0000 0040 0000 0000 0000 015d  .......@.......]
 * ...
 *
 * indent is applied to each line.  Ends with a CR.
 */
void outputStream::print_data(void* data, size_t len, bool with_ascii) {
  size_t limit = (len + 16) / 16 * 16;
  for (size_t i = 0; i < limit; ++i) {
    if (i % 16 == 0) {
      indent().print("%07x:", i);
    }
    if (i % 2 == 0) {
      print(" ");
    }
    if (i < len) {
      print("%02x", ((unsigned char*)data)[i]);
    } else {
      print("  ");
    }
    if ((i + 1) % 16 == 0) {
      if (with_ascii) {
        print("  ");
        for (size_t j = 0; j < 16; ++j) {
          size_t idx = i + j - 15;
          if (idx < len) {
            char c = ((char*)data)[idx];
            print("%c", c >= 32 && c <= 126 ? c : '.');
          }
        }
      }
      print_cr("");
    }
  }
}

stringStream::stringStream(size_t initial_size) : outputStream() {
  buffer_length = initial_size;
  buffer        = NEW_RESOURCE_ARRAY(char, buffer_length);
  buffer_pos    = 0;
  buffer_fixed  = false;
}

// useful for output to fixed chunks of memory, such as performance counters
stringStream::stringStream(char* fixed_buffer, size_t fixed_buffer_size) : outputStream() {
  buffer_length = fixed_buffer_size;
  buffer        = fixed_buffer;
  buffer_pos    = 0;
  buffer_fixed  = true;
}

void stringStream::write(const char* s, size_t len) {
  size_t write_len = len;               // number of non-null bytes to write
  size_t end = buffer_pos + len + 1;    // position after write and final '\0'
  if (end > buffer_length) {
    if (buffer_fixed) {
      // if buffer cannot resize, silently truncate
      end = buffer_length;
      write_len = end - buffer_pos - 1; // leave room for the final '\0'
    } else {
      // For small overruns, double the buffer.  For larger ones,
      // increase to the requested size.
      if (end < buffer_length * 2) {
        end = buffer_length * 2;
      }
      char* oldbuf = buffer;
      buffer = NEW_RESOURCE_ARRAY(char, end);
      strncpy(buffer, oldbuf, buffer_pos);
      buffer_length = end;
    }
  }
  // invariant: buffer is always null-terminated
  guarantee(buffer_pos + write_len + 1 <= buffer_length, "stringStream oob");
  buffer[buffer_pos + write_len] = 0;
  strncpy(buffer + buffer_pos, s, write_len);
  buffer_pos += write_len;

  // Note that the following does not depend on write_len.
  // This means that position and count get updated
  // even when overflow occurs.
  update_position(s, len);
}

char* stringStream::as_string() {
  char* copy = NEW_RESOURCE_ARRAY(char, buffer_pos+1);
  strncpy(copy, buffer, buffer_pos);
  copy[buffer_pos] = 0;  // terminating null
  return copy;
}

stringStream::~stringStream() {}

xmlStream*   xtty;
outputStream* tty;
outputStream* gclog_or_tty;
extern Mutex* tty_lock;

fileStream::fileStream(const char* file_name) {
  _file = fopen(file_name, "w");
  _need_close = true;
}

fileStream::fileStream(const char* file_name, const char* opentype) {
  _file = fopen(file_name, opentype);
  _need_close = true;
}

void fileStream::write(const char* s, size_t len) {
  if (_file != NULL)  {
    // Make an unused local variable to avoid warning from gcc 4.x compiler.
    size_t count = fwrite(s, 1, len, _file);
  }
  update_position(s, len);
}

long fileStream::fileSize() {
  long size = -1;
  if (_file != NULL) {
    long pos  = ::ftell(_file);
    if (::fseek(_file, 0, SEEK_END) == 0) {
      size = ::ftell(_file);
    }
    ::fseek(_file, pos, SEEK_SET);
  }
  return size;
}

char* fileStream::readln(char *data, int count ) {
  char * ret = ::fgets(data, count, _file);
  //Get rid of annoying \n char
  data[::strlen(data)-1] = '\0';
  return ret;
}

fileStream::~fileStream() {
  if (_file != NULL) {
    if (_need_close) fclose(_file);
    _file      = NULL;
  }
}

void fileStream::flush() {
  fflush(_file);
}

fdStream::fdStream(const char* file_name) {
  _fd = open(file_name, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  _need_close = true;
}

fdStream::~fdStream() {
  if (_fd != -1) {
    if (_need_close) close(_fd);
    _fd = -1;
  }
}

void fdStream::write(const char* s, size_t len) {
  if (_fd != -1) {
    // Make an unused local variable to avoid warning from gcc 4.x compiler.
    size_t count = ::write(_fd, s, (int)len);
  }
  update_position(s, len);
}

rotatingFileStream::~rotatingFileStream() {
  if (_file != NULL) {
    if (_need_close) fclose(_file);
    _file      = NULL;
    FREE_C_HEAP_ARRAY(char, _file_name, mtInternal);
    _file_name = NULL;
  }
}

rotatingFileStream::rotatingFileStream(const char* file_name) {
  _cur_file_num = 0;
  _bytes_writen = 0L;
  _file_name = NEW_C_HEAP_ARRAY(char, strlen(file_name)+10, mtInternal);
  jio_snprintf(_file_name, strlen(file_name)+10, "%s.%d", file_name, _cur_file_num);
  _file = fopen(_file_name, "w");
  _need_close = true;
}

rotatingFileStream::rotatingFileStream(const char* file_name, const char* opentype) {
  _cur_file_num = 0;
  _bytes_writen = 0L;
  _file_name = NEW_C_HEAP_ARRAY(char, strlen(file_name)+10, mtInternal);
  jio_snprintf(_file_name, strlen(file_name)+10, "%s.%d", file_name, _cur_file_num);
  _file = fopen(_file_name, opentype);
  _need_close = true;
}

void rotatingFileStream::write(const char* s, size_t len) {
  if (_file != NULL)  {
    // Make an unused local variable to avoid warning from gcc 4.x compiler.
    size_t count = fwrite(s, 1, len, _file);
    Atomic::add((jlong)count, &_bytes_writen);
  }
  update_position(s, len);
}

// rotate_log must be called from VMThread at safepoint. In case need change parameters
// for gc log rotation from thread other than VMThread, a sub type of VM_Operation
// should be created and be submitted to VMThread's operation queue. DO NOT call this
// function directly. Currently, it is safe to rotate log at safepoint through VMThread.
// That is, no mutator threads and concurrent GC threads run parallel with VMThread to
// write to gc log file at safepoint. If in future, changes made for mutator threads or
// concurrent GC threads to run parallel with VMThread at safepoint, write and rotate_log
// must be synchronized.
void rotatingFileStream::rotate_log() {
  if (_bytes_writen < (jlong)GCLogFileSize) return;
#ifdef ASSERT
  Thread *thread = Thread::current();
  assert(thread == NULL ||
         (thread->is_VM_thread() && SafepointSynchronize::is_at_safepoint()),
         "Must be VMThread at safepoint");
#endif
  if (NumberOfGCLogFiles == 1) {
    // rotate in same file
    rewind();
    _bytes_writen = 0L;
    return;
  }

  // rotate file in names file.0, file.1, file.2, ..., file.<MaxGCLogFileNumbers-1>
  // close current file, rotate to next file
  if (_file != NULL) {
    _cur_file_num ++;
    if (_cur_file_num >= NumberOfGCLogFiles) _cur_file_num = 0;
    jio_snprintf(_file_name, strlen(Arguments::gc_log_filename()) + 10, "%s.%d",
             Arguments::gc_log_filename(), _cur_file_num);
    fclose(_file);
    _file = NULL;
  }
  _file = fopen(_file_name, "w");
  if (_file != NULL) {
    _bytes_writen = 0L;
    _need_close = true;
  } else {
    tty->print_cr("failed to open rotation log file %s due to %s\n",
                  _file_name, strerror(errno));
    _need_close = false;
  }
}

defaultStream* defaultStream::instance = NULL;
int defaultStream::_output_fd = 1;
int defaultStream::_error_fd  = 2;
FILE* defaultStream::_output_stream = stdout;
FILE* defaultStream::_error_stream  = stderr;

#define LOG_MAJOR_VERSION 160
#define LOG_MINOR_VERSION 1

void defaultStream::init() {
  _inited = true;
  if (LogVMOutput || LogCompilation) {
    init_log();
  }
}

bool defaultStream::has_log_file() {
  // lazily create log file (at startup, LogVMOutput is false even
  // if +LogVMOutput is used, because the flags haven't been parsed yet)
  // For safer printing during fatal error handling, do not init logfile
  // if a VM error has been reported.
  if (!_inited && !is_error_reported())  init();
  return _log_file != NULL;
}

static const char* make_log_name(const char* log_name, const char* force_directory) {
  const char* basename = log_name;
  char file_sep = os::file_separator()[0];
  const char* cp;
  for (cp = log_name; *cp != '\0'; cp++) {
    if (*cp == '/' || *cp == file_sep) {
      basename = cp+1;
    }
  }
  const char* nametail = log_name;

  // Compute buffer length
  size_t buffer_length;
  if (force_directory != NULL) {
    buffer_length = strlen(force_directory) + strlen(os::file_separator()) +
                    strlen(basename) + 1;
  } else {
    buffer_length = strlen(log_name) + 1;
  }

  const char* star = strchr(basename, '*');
  int star_pos = (star == NULL) ? -1 : (star - nametail);
  int skip = 1;
  if (star == NULL) {
    // Try %p
    star = strstr(basename, "%p");
    if (star != NULL) {
      skip = 2;
    }
  }
  star_pos = (star == NULL) ? -1 : (star - nametail);

  char pid[32];
  if (star_pos >= 0) {
    jio_snprintf(pid, sizeof(pid), "%u", os::current_process_id());
    buffer_length += strlen(pid);
  }

  // Create big enough buffer.
  char *buf = NEW_C_HEAP_ARRAY(char, buffer_length, mtInternal);

  strcpy(buf, "");
  if (force_directory != NULL) {
    strcat(buf, force_directory);
    strcat(buf, os::file_separator());
    nametail = basename;       // completely skip directory prefix
  }

  if (star_pos >= 0) {
    // convert foo*bar.log or foo%pbar.log to foo123bar.log
    int buf_pos = (int) strlen(buf);
    strncpy(&buf[buf_pos], nametail, star_pos);
    strcpy(&buf[buf_pos + star_pos], pid);
    nametail += star_pos + skip;  // skip prefix and pid format
  }

  strcat(buf, nametail);      // append rest of name, or all of name
  return buf;
}

void defaultStream::init_log() {
  // %%% Need a MutexLocker?
  const char* log_name = LogFile != NULL ? LogFile : "hotspot.log";
  const char* try_name = make_log_name(log_name, NULL);
  fileStream* file = new(ResourceObj::C_HEAP, mtInternal) fileStream(try_name);
  if (!file->is_open()) {
    // Try again to open the file.
    char warnbuf[O_BUFLEN*2];
    jio_snprintf(warnbuf, sizeof(warnbuf),
                 "Warning:  Cannot open log file: %s\n", try_name);
    // Note:  This feature is for maintainer use only.  No need for L10N.
    jio_print(warnbuf);
    FREE_C_HEAP_ARRAY(char, try_name, mtInternal);
    try_name = make_log_name("hs_pid%p.log", os::get_temp_directory());
    jio_snprintf(warnbuf, sizeof(warnbuf),
                 "Warning:  Forcing option -XX:LogFile=%s\n", try_name);
    jio_print(warnbuf);
    delete file;
    file = new(ResourceObj::C_HEAP, mtInternal) fileStream(try_name);
    FREE_C_HEAP_ARRAY(char, try_name, mtInternal);
  }
  if (file->is_open()) {
    _log_file = file;
    xmlStream* xs = new(ResourceObj::C_HEAP, mtInternal) xmlStream(file);
    _outer_xmlStream = xs;
    if (this == tty)  xtty = xs;
    // Write XML header.
    xs->print_cr("<?xml version='1.0' encoding='UTF-8'?>");
    // (For now, don't bother to issue a DTD for this private format.)
    jlong time_ms = os::javaTimeMillis() - tty->time_stamp().milliseconds();
    // %%% Should be: jlong time_ms = os::start_time_milliseconds(), if
    // we ever get round to introduce that method on the os class
    xs->head("hotspot_log version='%d %d'"
             " process='%d' time_ms='"INT64_FORMAT"'",
             LOG_MAJOR_VERSION, LOG_MINOR_VERSION,
             os::current_process_id(), time_ms);
    // Write VM version header immediately.
    xs->head("vm_version");
    xs->head("name"); xs->text("%s", VM_Version::vm_name()); xs->cr();
    xs->tail("name");
    xs->head("release"); xs->text("%s", VM_Version::vm_release()); xs->cr();
    xs->tail("release");
    xs->head("info"); xs->text("%s", VM_Version::internal_vm_info_string()); xs->cr();
    xs->tail("info");
    xs->tail("vm_version");
    // Record information about the command-line invocation.
    xs->head("vm_arguments");  // Cf. Arguments::print_on()
    if (Arguments::num_jvm_flags() > 0) {
      xs->head("flags");
      Arguments::print_jvm_flags_on(xs->text());
      xs->tail("flags");
    }
    if (Arguments::num_jvm_args() > 0) {
      xs->head("args");
      Arguments::print_jvm_args_on(xs->text());
      xs->tail("args");
    }
    if (Arguments::java_command() != NULL) {
      xs->head("command"); xs->text()->print_cr("%s", Arguments::java_command());
      xs->tail("command");
    }
    if (Arguments::sun_java_launcher() != NULL) {
      xs->head("launcher"); xs->text()->print_cr("%s", Arguments::sun_java_launcher());
      xs->tail("launcher");
    }
    if (Arguments::system_properties() !=  NULL) {
      xs->head("properties");
      // Print it as a java-style property list.
      // System properties don't generally contain newlines, so don't bother with unparsing.
      for (SystemProperty* p = Arguments::system_properties(); p != NULL; p = p->next()) {
        xs->text()->print_cr("%s=%s", p->key(), p->value());
      }
      xs->tail("properties");
    }
    xs->tail("vm_arguments");
    // tty output per se is grouped under the <tty>...</tty> element.
    xs->head("tty");
    // All further non-markup text gets copied to the tty:
    xs->_text = this;  // requires friend declaration!
  } else {
    delete(file);
    // and leave xtty as NULL
    LogVMOutput = false;
    DisplayVMOutput = true;
    LogCompilation = false;
  }
}

// finish_log() is called during normal VM shutdown. finish_log_on_error() is
// called by ostream_abort() after a fatal error.
//
void defaultStream::finish_log() {
  xmlStream* xs = _outer_xmlStream;
  xs->done("tty");

  // Other log forks are appended here, at the End of Time:
  CompileLog::finish_log(xs->out());  // write compile logging, if any, now

  xs->done("hotspot_log");
  xs->flush();

  fileStream* file = _log_file;
  _log_file = NULL;

  delete _outer_xmlStream;
  _outer_xmlStream = NULL;

  file->flush();
  delete file;
}

void defaultStream::finish_log_on_error(char *buf, int buflen) {
  xmlStream* xs = _outer_xmlStream;

  if (xs && xs->out()) {

    xs->done_raw("tty");

    // Other log forks are appended here, at the End of Time:
    CompileLog::finish_log_on_error(xs->out(), buf, buflen);  // write compile logging, if any, now

    xs->done_raw("hotspot_log");
    xs->flush();

    fileStream* file = _log_file;
    _log_file = NULL;
    _outer_xmlStream = NULL;

    if (file) {
      file->flush();

      // Can't delete or close the file because delete and fclose aren't
      // async-safe. We are about to die, so leave it to the kernel.
      // delete file;
    }
  }
}

intx defaultStream::hold(intx writer_id) {
  bool has_log = has_log_file();  // check before locking
  if (// impossible, but who knows?
      writer_id == NO_WRITER ||

      // bootstrap problem
      tty_lock == NULL ||

      // can't grab a lock or call Thread::current() if TLS isn't initialized
      ThreadLocalStorage::thread() == NULL ||

      // developer hook
      !SerializeVMOutput ||

      // VM already unhealthy
      is_error_reported() ||

      // safepoint == global lock (for VM only)
      (SafepointSynchronize::is_synchronizing() &&
       Thread::current()->is_VM_thread())
      ) {
    // do not attempt to lock unless we know the thread and the VM is healthy
    return NO_WRITER;
  }
  if (_writer == writer_id) {
    // already held, no need to re-grab the lock
    return NO_WRITER;
  }
  tty_lock->lock_without_safepoint_check();
  // got the lock
  if (writer_id != _last_writer) {
    if (has_log) {
      _log_file->bol();
      // output a hint where this output is coming from:
      _log_file->print_cr("<writer thread='"INTX_FORMAT"'/>", writer_id);
    }
    _last_writer = writer_id;
  }
  _writer = writer_id;
  return writer_id;
}

void defaultStream::release(intx holder) {
  if (holder == NO_WRITER) {
    // nothing to release:  either a recursive lock, or we scribbled (too bad)
    return;
  }
  if (_writer != holder) {
    return;  // already unlocked, perhaps via break_tty_lock_for_safepoint
  }
  _writer = NO_WRITER;
  tty_lock->unlock();
}


// Yuck:  jio_print does not accept char*/len.
static void call_jio_print(const char* s, size_t len) {
  char buffer[O_BUFLEN+100];
  if (len > sizeof(buffer)-1) {
    warning("increase O_BUFLEN in ostream.cpp -- output truncated");
    len = sizeof(buffer)-1;
  }
  strncpy(buffer, s, len);
  buffer[len] = '\0';
  jio_print(buffer);
}


void defaultStream::write(const char* s, size_t len) {
  intx thread_id = os::current_thread_id();
  intx holder = hold(thread_id);

  if (DisplayVMOutput &&
      (_outer_xmlStream == NULL || !_outer_xmlStream->inside_attrs())) {
    // print to output stream. It can be redirected by a vfprintf hook
    if (s[len] == '\0') {
      jio_print(s);
    } else {
      call_jio_print(s, len);
    }
  }

  // print to log file
  if (has_log_file()) {
    int nl0 = _newlines;
    xmlTextStream::write(s, len);
    // flush the log file too, if there were any newlines
    if (nl0 != _newlines){
      flush();
    }
  } else {
    update_position(s, len);
  }

  release(holder);
}

intx ttyLocker::hold_tty() {
  if (defaultStream::instance == NULL)  return defaultStream::NO_WRITER;
  intx thread_id = os::current_thread_id();
  return defaultStream::instance->hold(thread_id);
}

void ttyLocker::release_tty(intx holder) {
  if (holder == defaultStream::NO_WRITER)  return;
  defaultStream::instance->release(holder);
}

bool ttyLocker::release_tty_if_locked() {
  intx thread_id = os::current_thread_id();
  if (defaultStream::instance->writer() == thread_id) {
    // release the lock and return true so callers know if was
    // previously held.
    release_tty(thread_id);
    return true;
  }
  return false;
}

void ttyLocker::break_tty_lock_for_safepoint(intx holder) {
  if (defaultStream::instance != NULL &&
      defaultStream::instance->writer() == holder) {
    if (xtty != NULL) {
      xtty->print_cr("<!-- safepoint while printing -->");
    }
    defaultStream::instance->release(holder);
  }
  // (else there was no lock to break)
}

void ostream_init() {
  if (defaultStream::instance == NULL) {
    defaultStream::instance = new(ResourceObj::C_HEAP, mtInternal) defaultStream();
    tty = defaultStream::instance;

    // We want to ensure that time stamps in GC logs consider time 0
    // the time when the JVM is initialized, not the first time we ask
    // for a time stamp. So, here, we explicitly update the time stamp
    // of tty.
    tty->time_stamp().update_to(1);
  }
}

void ostream_init_log() {
  // For -Xloggc:<file> option - called in runtime/thread.cpp
  // Note : this must be called AFTER ostream_init()

  gclog_or_tty = tty; // default to tty
  if (Arguments::gc_log_filename() != NULL) {
    fileStream * gclog  = UseGCLogFileRotation ?
                          new(ResourceObj::C_HEAP, mtInternal)
                             rotatingFileStream(Arguments::gc_log_filename()) :
                          new(ResourceObj::C_HEAP, mtInternal)
                             fileStream(Arguments::gc_log_filename());
    if (gclog->is_open()) {
      // now we update the time stamp of the GC log to be synced up
      // with tty.
      gclog->time_stamp().update_to(tty->time_stamp().ticks());
    }
    gclog_or_tty = gclog;
  }

  // If we haven't lazily initialized the logfile yet, do it now,
  // to avoid the possibility of lazy initialization during a VM
  // crash, which can affect the stability of the fatal error handler.
  defaultStream::instance->has_log_file();
}

// ostream_exit() is called during normal VM exit to finish log files, flush
// output and free resource.
void ostream_exit() {
  static bool ostream_exit_called = false;
  if (ostream_exit_called)  return;
  ostream_exit_called = true;
  if (gclog_or_tty != tty) {
      delete gclog_or_tty;
  }
  {
      // we temporaly disable PrintMallocFree here
      // as otherwise it'll lead to using of almost deleted
      // tty or defaultStream::instance in logging facility
      // of HeapFree(), see 6391258
      DEBUG_ONLY(FlagSetting fs(PrintMallocFree, false);)
      if (tty != defaultStream::instance) {
          delete tty;
      }
      if (defaultStream::instance != NULL) {
          delete defaultStream::instance;
      }
  }
  tty = NULL;
  xtty = NULL;
  gclog_or_tty = NULL;
  defaultStream::instance = NULL;
}

// ostream_abort() is called by os::abort() when VM is about to die.
void ostream_abort() {
  // Here we can't delete gclog_or_tty and tty, just flush their output
  if (gclog_or_tty) gclog_or_tty->flush();
  if (tty) tty->flush();

  if (defaultStream::instance != NULL) {
    static char buf[4096];
    defaultStream::instance->finish_log_on_error(buf, sizeof(buf));
  }
}

staticBufferStream::staticBufferStream(char* buffer, size_t buflen,
                                       outputStream *outer_stream) {
  _buffer = buffer;
  _buflen = buflen;
  _outer_stream = outer_stream;
  // compile task prints time stamp relative to VM start
  _stamp.update_to(1);
}

void staticBufferStream::write(const char* c, size_t len) {
  _outer_stream->print_raw(c, (int)len);
}

void staticBufferStream::flush() {
  _outer_stream->flush();
}

void staticBufferStream::print(const char* format, ...) {
  va_list ap;
  va_start(ap, format);
  size_t len;
  const char* str = do_vsnprintf(_buffer, _buflen, format, ap, false, len);
  write(str, len);
  va_end(ap);
}

void staticBufferStream::print_cr(const char* format, ...) {
  va_list ap;
  va_start(ap, format);
  size_t len;
  const char* str = do_vsnprintf(_buffer, _buflen, format, ap, true, len);
  write(str, len);
  va_end(ap);
}

void staticBufferStream::vprint(const char *format, va_list argptr) {
  size_t len;
  const char* str = do_vsnprintf(_buffer, _buflen, format, argptr, false, len);
  write(str, len);
}

void staticBufferStream::vprint_cr(const char* format, va_list argptr) {
  size_t len;
  const char* str = do_vsnprintf(_buffer, _buflen, format, argptr, true, len);
  write(str, len);
}

bufferedStream::bufferedStream(size_t initial_size, size_t bufmax) : outputStream() {
  buffer_length = initial_size;
  buffer        = NEW_C_HEAP_ARRAY(char, buffer_length, mtInternal);
  buffer_pos    = 0;
  buffer_fixed  = false;
  buffer_max    = bufmax;
}

bufferedStream::bufferedStream(char* fixed_buffer, size_t fixed_buffer_size, size_t bufmax) : outputStream() {
  buffer_length = fixed_buffer_size;
  buffer        = fixed_buffer;
  buffer_pos    = 0;
  buffer_fixed  = true;
  buffer_max    = bufmax;
}

void bufferedStream::write(const char* s, size_t len) {

  if(buffer_pos + len > buffer_max) {
    flush();
  }

  size_t end = buffer_pos + len;
  if (end >= buffer_length) {
    if (buffer_fixed) {
      // if buffer cannot resize, silently truncate
      len = buffer_length - buffer_pos - 1;
    } else {
      // For small overruns, double the buffer.  For larger ones,
      // increase to the requested size.
      if (end < buffer_length * 2) {
        end = buffer_length * 2;
      }
      buffer = REALLOC_C_HEAP_ARRAY(char, buffer, end, mtInternal);
      buffer_length = end;
    }
  }
  memcpy(buffer + buffer_pos, s, len);
  buffer_pos += len;
  update_position(s, len);
}

char* bufferedStream::as_string() {
  char* copy = NEW_RESOURCE_ARRAY(char, buffer_pos+1);
  strncpy(copy, buffer, buffer_pos);
  copy[buffer_pos] = 0;  // terminating null
  return copy;
}

bufferedStream::~bufferedStream() {
  if (!buffer_fixed) {
    FREE_C_HEAP_ARRAY(char, buffer, mtInternal);
  }
}

#ifndef PRODUCT

#if defined(SOLARIS) || defined(LINUX) || defined(_ALLBSD_SOURCE)
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#endif

// Network access
networkStream::networkStream() : bufferedStream(1024*10, 1024*10) {

  _socket = -1;

  int result = os::socket(AF_INET, SOCK_STREAM, 0);
  if (result <= 0) {
    assert(false, "Socket could not be created!");
  } else {
    _socket = result;
  }
}

int networkStream::read(char *buf, size_t len) {
  return os::recv(_socket, buf, (int)len, 0);
}

void networkStream::flush() {
  if (size() != 0) {
    int result = os::raw_send(_socket, (char *)base(), size(), 0);
    assert(result != -1, "connection error");
    assert(result == (int)size(), "didn't send enough data");
  }
  reset();
}

networkStream::~networkStream() {
  close();
}

void networkStream::close() {
  if (_socket != -1) {
    flush();
    os::socket_close(_socket);
    _socket = -1;
  }
}

bool networkStream::connect(const char *ip, short port) {

  struct sockaddr_in server;
  server.sin_family = AF_INET;
  server.sin_port = htons(port);

  server.sin_addr.s_addr = inet_addr(ip);
  if (server.sin_addr.s_addr == (uint32_t)-1) {
    struct hostent* host = os::get_host_by_name((char*)ip);
    if (host != NULL) {
      memcpy(&server.sin_addr, host->h_addr_list[0], host->h_length);
    } else {
      return false;
    }
  }


  int result = os::connect(_socket, (struct sockaddr*)&server, sizeof(struct sockaddr_in));
  return (result >= 0);
}

#endif