ACE/ace/Monitor_Control/CPU_Load_Monitor.cpp

   1 #include "ace/Monitor_Control/CPU_Load_Monitor.h"
   2
   3 #if defined (ACE_HAS_MONITOR_FRAMEWORK) && (ACE_HAS_MONITOR_FRAMEWORK == 1)
   4
   5 #if defined (ACE_LINUX)
   6 #include "ace/OS_NS_stdio.h"
   7 #endif
   8
   9 #include "ace/Log_Msg.h"
  10 #include "ace/OS_NS_string.h"
  11
  12 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  13
  14 namespace ACE
  15 {
  16   namespace Monitor_Control
  17   {
  18     const char* CPU_Load_Monitor::default_name_ =
  19       "OS/Processor/CPULoad";
  20
  21     CPU_Load_Monitor::CPU_Load_Monitor (const char* name)
  22       : Monitor_Base (name, Monitor_Control_Types::MC_NUMBER)
  23 #if defined (ACE_HAS_WIN32_PDH)
  24       , Windows_Monitor (ACE_TEXT("\\Processor(_Total)\\% Processor Time"))
  25 #endif
  26 #if defined (ACE_LINUX)
  27       , user_ (0)
  28       , wait_ (0)
  29       , kernel_ (0)
  30       , idle_ (0)
  31       , prev_idle_ (0)
  32       , prev_total_ (0.0)
  33 #endif
  34 #if defined (ACE_LINUX)
  35       , file_ptr_ (0)
  36 #endif
  37     {
  38       this->init ();
  39     }
  40
  41     void
  42     CPU_Load_Monitor::update ()
  43     {
  44 #if defined (ACE_HAS_WIN32_PDH)
  45       this->update_i ();
  46       this->receive (this->value_);
  47 #elif defined (ACE_LINUX)
  48       this->access_proc_stat (&this->idle_);
  49 #elif defined (ACE_HAS_KSTAT)
  50       this->access_kstats (&this->idle_);
  51 #endif
  52
  53 #if defined (ACE_LINUX)
  54       double delta_idle = this->idle_ - this->prev_idle_;
  55       double total =
  56         this->user_ + this->wait_ + this->kernel_ + this->idle_;
  57       double delta_total = total - this->prev_total_;
  58
  59       if (ACE::is_equal (delta_total, 0.0))
  60         {
  61           /// The system hasn't updated /proc/stat since the last call
  62           /// to update(), we must avoid dividing by 0.
  63           return;
  64         }
  65
  66       double percent_cpu_load = 100.0 - (delta_idle / delta_total * 100.0);
  67
  68       /// Stores value and timestamp with thread-safety.
  69       this->receive (percent_cpu_load);
  70
  71       this->prev_idle_ = this->idle_;
  72       this->prev_total_ = total;
  73 #endif
  74     }
  75
  76     const char*
  77     CPU_Load_Monitor::default_name ()
  78     {
  79       return CPU_Load_Monitor::default_name_;
  80     }
  81
  82     void
  83     CPU_Load_Monitor::clear_i ()
  84     {
  85 #if defined (ACE_HAS_WIN32_PDH)
  86       this->clear_impl ();
  87 #endif
  88
  89       this->init ();
  90       this->Monitor_Base::clear_i ();
  91     }
  92
  93     void
  94     CPU_Load_Monitor::init ()
  95     {
  96 #if defined (ACE_LINUX)
  97       /// All data in this file are stored as running 'jiffy' totals, so we
  98       /// get values here in the constructor to subtract for the difference
  99       /// in subsequent calls.
 100       this->access_proc_stat (&this->prev_idle_);
 101
 102       this->prev_total_ =
 103         this->user_ + this->wait_ + this->kernel_ + this->prev_idle_;
 104 #endif
 105     }
 106
 107 #if defined (ACE_LINUX)
 108     void
 109     CPU_Load_Monitor::access_proc_stat (unsigned long *which_idle)
 110     {
 111       this->file_ptr_ = ACE_OS::fopen (ACE_TEXT ("/proc/stat"),
 112                                        ACE_TEXT ("r"));
 113
 114       if (this->file_ptr_ == 0)
 115         {
 116           ACELIB_ERROR ((LM_ERROR,
 117                       ACE_TEXT ("CPU load - opening /proc/stat failed\n")));
 118           return;
 119         }
 120
 121       char *item = 0;
 122       char *arg = 0;
 123
 124       while ((ACE_OS::fgets (buf_, sizeof (buf_), file_ptr_)) != 0)
 125         {
 126           item = ACE_OS::strtok (this->buf_, " \t\n");
 127           arg = ACE_OS::strtok (0, "\n");
 128
 129           if (item == 0 || arg == 0)
 130             {
 131               continue;
 132             }
 133
 134           if (ACE_OS::strcmp (item, "cpu") == 0)
 135             {
 136               sscanf (arg,
 137                       "%lu %lu %lu %lu",
 138                       &this->user_,
 139                       &this->wait_,
 140                       &this->kernel_,
 141                       which_idle);
 142               break;
 143             }
 144         }
 145
 146       ACE_OS::fclose (this->file_ptr_);
 147     }
 148 #endif
 149   }
 150 }
 151
 152 ACE_END_VERSIONED_NAMESPACE_DECL
 153
 154 #endif /* ACE_HAS_MONITOR_FRAMEWORK==1 */