nucleus/library/processes/heartbeat.cpp

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   4 /*****************************************************************************\
   5 *                                                                             *
   6 *  Name   : heartbeat                                                         *
   7 *  Author : Chris Koeritz                                                     *
   8 *                                                                             *
   9 *******************************************************************************
  10 * Copyright (c) 1996-$now By Author.  This program is free software; you can  *
  11 * redistribute it and/or modify it under the terms of the GNU General Public  *
  12 * License as published by the Free Software Foundation; either version 2 of   *
  13 * the License or (at your option) any later version.  This is online at:      *
  14 *     http://www.fsf.org/copyleft/gpl.html                                    *
  15 * Please send any updates to: fred@gruntose.com                               *
  16 \*****************************************************************************/
  17
  18 #include "heartbeat.h"
  19
  20 #include <basis/astring.h>
  21 #include <basis/functions.h>
  22 #include <timely/time_stamp.h>
  23
  24 using namespace basis;
  25 using namespace timely;
  26
  27 namespace processes {
  28
  29 heartbeat::heartbeat(int misses_allowed, int check_interval)
  30 : _next_heartbeat(new time_stamp()),
  31   _check_interval(0),
  32   _misses_allowed(0),
  33   _misses(0)
  34 { reset(misses_allowed, check_interval); }
  35
  36 heartbeat::heartbeat(const heartbeat &to_copy)
  37 : root_object(),
  38   _next_heartbeat(new time_stamp()),
  39   _check_interval(0),
  40   _misses_allowed(0),
  41   _misses(0)
  42 { *this = to_copy; }
  43
  44 heartbeat::~heartbeat() { WHACK(_next_heartbeat); }
  45
  46 time_stamp heartbeat::heartbeat_time() const { return *_next_heartbeat; }
  47
  48 bool heartbeat::due() const { return time_left() <= 0; }
  49
  50 void heartbeat::made_request() { _misses++; reset_next_beat(); }
  51
  52 void heartbeat::kabump() { _misses = 0; reset_next_beat(); }
  53
  54 void heartbeat::reset_next_beat()
  55 { *_next_heartbeat = time_stamp(_check_interval); }
  56
  57 int heartbeat::time_left() const
  58 { return int(_next_heartbeat->value() - time_stamp().value()); }
  59
  60 bool heartbeat::dead() const
  61 {
  62   // two cases mean the timer's dead; (1) if the misses are already too high,
  63   // or (2) if the heartbeat is due and the misses are as many as allowed.
  64   return (_misses > _misses_allowed)
  65       || (due() && (_misses >= _misses_allowed));
  66 }
  67
  68 void heartbeat::reset(int misses_allowed, int check_interval)
  69 {
  70   _misses_allowed = misses_allowed;
  71   _misses = 0;
  72   _check_interval = check_interval;
  73   reset_next_beat();
  74 }
  75
  76 astring heartbeat::text_form(bool detailed) const
  77 {
  78   astring to_return = (dead()? astring("expired, ") : astring("alive, "));
  79   to_return += (!dead() && due() ? astring("due now, ")
  80       : astring::empty_string());
  81   to_return += a_sprintf("beats left=%d", misses_left());
  82   if (detailed) {
  83     to_return += a_sprintf(", missed=%d, interval=%d, ",
  84         missed_so_far(), checking_interval());
  85     to_return += astring("next=") + heartbeat_time().text_form();
  86   }
  87   return to_return;
  88 }
  89
  90 heartbeat &heartbeat::operator =(const heartbeat &to_copy)
  91 {
  92   if (this == &to_copy) return *this;
  93   _check_interval = to_copy._check_interval;
  94   _misses_allowed = to_copy._misses_allowed;
  95   _misses = to_copy._misses;
  96   *_next_heartbeat = *to_copy._next_heartbeat;
  97   return *this;
  98 }
  99
 100 } //namespace.
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