dining.c

来自「C++ SOCKET 类」· C语言 代码 · 共 83 行

#include <thread.h>

#include "philosopher.h"
#include "dining.h"

using namespace cpp_threads;

dining::dining(int p_no)
{
  p_fork = new Mutex[p_no];
  p      = (Pthread **)malloc(sizeof(Pthread*)*(p_no+1));
  for( philosophers=0;philosophers<p_no;philosophers++ )
    p[philosophers] = new philosopher(philosophers,p_no,this);
}

dining::~dining()
{
  int n = 0;
 
  // house keeping.
  for( n=0;n<philosophers;n++ )
    delete (p[n]);
  delete p;
  delete[] p_fork;
  cout << "Diner closing." << endl;
}

int dining::nr()
{
  return philosophers;
}

bool dining::isLocked(int p_no)
{
  bool locked;

  if (locked = (p_fork[p_no].tryLock() == 0))
    p_fork[p_no].unLock();
  return !locked;
}

void dining::finished(int)
{
  p_finish.post();
}

void dining::open()
{
  int n = 0;

  for( n=0;n<philosophers;n++ )
    ((philosopher *)p[n])->run();
  for(n=0;n<philosophers;n++) {
    p_finish.wait();
    cout << philosophers - n -1 << " little indians, hanging on the wall" << endl;
  }
}

bool dining::get_forks(int p_nr)
{
  int lfork,rfork;

  lfork = p_nr-1 >= 0 ? p_nr-1 : nr()-1;
  rfork = lfork+1 >= nr() ? 0 : lfork+1;
  if ( p_fork[lfork].tryLock() == 0 )
    if ( p_fork[rfork].tryLock() == 0 )
      return true;
    else
      p_fork[lfork].unLock();
  return false;
}

void dining::put_forks(int p_nr)
{
  int lfork,rfork;

  lfork = p_nr-1 >= 0 ? p_nr-1 : nr()-1;
  rfork = lfork+1 >= nr() ? 0 : lfork+1;
  p_fork[lfork].unLock();
  p_fork[rfork].unLock();
}