release/src/router/apcupsd/include/aqueue.h

   1 #ifndef __AQUEUE_H
   2 #define __AQUEUE_H
   3
   4 #include <pthread.h>
   5 #include <sys/time.h>
   6 #include "alist.h"
   7 #include "autil.h"
   8
   9 template<class T>
  10 class aqueue
  11 {
  12 public:
  13
  14    aqueue()
  15    {
  16       pthread_mutex_init(&_mutex, NULL);
  17       pthread_cond_init(&_condvar, NULL);
  18    }
  19
  20    ~aqueue()
  21    {
  22       pthread_cond_destroy(&_condvar);
  23       pthread_mutex_destroy(&_mutex);
  24    }
  25
  26    void enqueue(const T &elem)
  27    {
  28       pthread_mutex_lock(&_mutex);
  29       _queue.append(elem);
  30       pthread_mutex_unlock(&_mutex);
  31       pthread_cond_signal(&_condvar);
  32    }
  33
  34    bool dequeue(T& elem, int msec = TIMEOUT_FOREVER)
  35    {
  36       int rc = 0;
  37
  38       pthread_mutex_lock(&_mutex);
  39       if (msec != TIMEOUT_FOREVER) {
  40          struct timespec abstime;
  41          calc_abstimeout(msec, &abstime);
  42          while (rc == 0 && _queue.empty())
  43             rc = pthread_cond_timedwait(&_condvar, &_mutex, &abstime);
  44       } else {
  45          while (rc == 0 && _queue.empty())
  46             rc = pthread_cond_wait(&_condvar, &_mutex);
  47       }
  48
  49       if (rc) {
  50          pthread_mutex_unlock(&_mutex);
  51          return false;
  52       }
  53
  54       elem = _queue.first();
  55       _queue.remove_first();
  56       pthread_mutex_unlock(&_mutex);
  57       return true;
  58    }
  59
  60    T dequeue()
  61    {
  62       pthread_mutex_lock(&_mutex);
  63
  64       int rc = 0;
  65       while (rc == 0 && _queue.empty())
  66          rc = pthread_cond_wait(&_condvar, &_mutex);
  67
  68       T elem = _queue.first();
  69       _queue.remove_first();
  70       pthread_mutex_unlock(&_mutex);
  71       return elem;
  72    }
  73
  74    bool empty()
  75    {
  76       pthread_mutex_lock(&_mutex);
  77       bool tmp = _queue.empty();
  78       pthread_mutex_unlock(&_mutex);
  79       return tmp;
  80    }
  81
  82    void clear()
  83    {
  84       pthread_mutex_lock(&_mutex);
  85       _queue.clear();
  86       pthread_mutex_unlock(&_mutex);
  87    }
  88
  89 private:
  90
  91    static const int TIMEOUT_FOREVER = -1;
  92    pthread_mutex_t _mutex;
  93    pthread_cond_t _condvar;
  94    alist<T> _queue;
  95
  96    // Prevent use
  97    aqueue(const aqueue<T> &rhs);
  98    aqueue<T> &operator=(const aqueue<T> &rhs);
  99 };
 100
 101 #endif