philosopher.c

来自「多线程库」· C语言 代码 · 共 48 行

#include "philosopher.h"

philosopher::philosopher(int n, int forks, void *arg)
  : pthread(arg)
{
  _nr = n;
  _forks = forks;
  _count = forks;
}

philosopher::~philosopher()
{
  delete p_fork;
}

int philosopher::thread(void *ptr)
{
  bool fork_v = false;
  int lfork, rfork;
  
  application = (dining *)ptr;
  lfork = _nr-1 >= 0 ? _nr-1 : _forks-1;
  rfork = lfork+1 >= _forks ? 0 : lfork+1;
  while(_count-- > 0) {
    cout.form("Philosopher %d: looking for %d,%d\n", _nr, lfork, rfork);
    while( fork_v == false ) {
      if (application->fork(lfork).trylock() == 0) {
	if (application->fork(rfork).trylock() == 0)
	  fork_v = true;
	else
	  application->fork(lfork).unlock();
      }
    }
    cout.form("Philosopher %d: using (%d,%d).\n", _nr, lfork, rfork);
    sleep(2);
    fork_v = false;
    cout.form("Philosopher %d: sleeping\n", _nr);
    application->fork(lfork).unlock();
    application->fork(rfork).unlock();
    sleep(2);
  }
  application->finished();
  cout << _nr << " has finished dining." << endl;
  return 0;
}