projects/stargazer/eventloop.cpp

   1 #include <csignal>
   2 #include <cerrno>
   3 #include <cstring>
   4
   5 #include "stg/locker.h"
   6 #include "stg/common.h"
   7 #include "eventloop.h"
   8
   9 EVENT_LOOP::EVENT_LOOP()
  10     : ACTIONS_LIST(),
  11       _running(false),
  12       _stopped(true),
  13       _tid(),
  14       _mutex(),
  15       _condition()
  16 {
  17 pthread_mutex_init(&_mutex, NULL);
  18 pthread_cond_init(&_condition, NULL);
  19 }
  20
  21 EVENT_LOOP::~EVENT_LOOP()
  22 {
  23 pthread_cond_destroy(&_condition);
  24 pthread_mutex_destroy(&_mutex);
  25 }
  26
  27 bool EVENT_LOOP::Start()
  28 {
  29 _running = true;
  30 if (pthread_create(&_tid, NULL, Run, this))
  31     {
  32     printfd(__FILE__, "EVENT_LOOP::Start - Failed to create thread: '%s'\n", strerror(errno));
  33     return true;
  34     }
  35 return false;
  36 }
  37
  38 bool EVENT_LOOP::Stop()
  39 {
  40 _running = false;
  41 // Wake up thread
  42 pthread_cond_signal(&_condition);
  43 // Wait until thread exit
  44 pthread_join(_tid, NULL);
  45 return false;
  46 }
  47
  48 void * EVENT_LOOP::Run(void * self)
  49 {
  50 EVENT_LOOP * ev = static_cast<EVENT_LOOP *>(self);
  51 ev->Runner();
  52 return NULL;
  53 }
  54
  55 void EVENT_LOOP::Runner()
  56 {
  57 sigset_t signalSet;
  58 sigfillset(&signalSet);
  59 pthread_sigmask(SIG_BLOCK, &signalSet, NULL);
  60
  61 _stopped = false;
  62 printfd(__FILE__, "EVENT_LOOP::Runner - Before start\n");
  63 while (_running)
  64     {
  65         {
  66         STG_LOCKER lock(&_mutex);
  67         // Check for any actions...
  68         if (empty())
  69             {
  70             // ... and sleep until new actions added
  71             printfd(__FILE__, "EVENT_LOOP::Runner - Sleeping until new actions arrived\n");
  72             pthread_cond_wait(&_condition, &_mutex);
  73             }
  74         // Check for running after wake up
  75         if (!_running)
  76             {
  77             // Don't process any actions if stopping
  78             break;
  79             }
  80         }
  81     // Create new empty actions list
  82     ACTIONS_LIST local;
  83     // Fast swap with current
  84     swap(local);
  85     // Invoke all current actions
  86     printfd(__FILE__, "EVENT_LOOP::Runner - Invoke %d actions\n", local.size());
  87     local.InvokeAll();
  88     }
  89 printfd(__FILE__, "EVENT_LOOP::Runner - Before stop\n");
  90 _stopped = true;
  91 }
  92
  93 namespace {
  94
  95 pthread_mutex_t singletonMutex;
  96
  97 }
  98
  99 EVENT_LOOP & EVENT_LOOP_SINGLETON::GetInstance()
 100 {
 101 // Double-checking technique
 102 if (!_instance)
 103     {
 104     STG_LOCKER lock(&singletonMutex);
 105     if (!_instance)
 106         {
 107         CreateInstance();
 108         }
 109     }
 110 return *_instance;
 111 }
 112
 113 void EVENT_LOOP_SINGLETON::CreateInstance()
 114 {
 115 static EVENT_LOOP loop;
 116 _instance = &loop;
 117 }
 118
 119 EVENT_LOOP * EVENT_LOOP_SINGLETON::_instance = NULL;