互斥锁的简单实现

class Peterson: public Lock
{
   private:
     bool flag[2];
     int turn;
   public:
     void lock() {
        int i = Thread.getId();// 0 or 1
        flag[i] = true;
        turn = j;
        while(flag[j] && turn == j);
      }
      void unlock() {
         int i = Thread.getId();
         flag[i] = false;
      }
}

class Bakery: public Lock {
  private: 
    bool flag[];
    Label label[];
  public:
    Bakery (int n) {
      flag = new bool[n];
      label = new Label[n];
      for(int i=0; i<n; i++) {
        flag[i] = flase;
        label[i]  =  0;
      }
      void Lock() {
         int i = Thread.getId();
         flag[i] = true;               
         label[i] = max(label[0], ..., label[n-1]) +1;
         while((exist k!=i)(flag[k] && label[k]<label[i])
       }
       void unlock() {
          flag[Thread.getId()] = false;
       }
     }
}

非原创，当时记录到本地，突然想起来就发出来了，侵删。