《Cracking the Coding Interview》——第16章：线程与锁——题目4

 1 // 16.4 Design a class which provides a lock only if no deadlock would take place.
 2 1. The class will maintain a list of all locks that would be requested by different processes.
 3     private Vector<Lock> locks;
 4 2. The class will have a real-time record of which processes are using which locks. Mapping the process ID with a queue recording the locks it is using.
 5     private HashMap<int, Queue<Lock> > lockOccupations;
 6 3. The class will perform deadlock detection before assigning a certain lock to a certain process.
 7     private bool deadLockDetection(int processID, int lockID);
 8 4. The class will provide a public method to assign a lock to a process.
 9     public bool getLock(int processID, int lockID);
10 
11 About dead lock detection:
12     Generally, dead lock detection is about detecting a loop in a directed graph. Using DFS will be a solution.