Dekker算法python语言

Dekker算法是一种用于解决并发访问共享资源的经典算法之一。它最早由Edsger W. Dijkstra于1965年提出，用于实现互斥访问临界区的同步机制。以下是Dekker算法在Python语言中的实现示例：

from threading import Thread, Lock

class DekkerAlgorithm:
    def __init__(self):
        self.flag = [False, False]
        self.turn = 0

    def lock(self, process):
        other_process = 1 - process
        self.flag[process] = True
        while self.flag[other_process]:
            if self.turn == other_process:
                self.flag[process] = False
                while self.turn == other_process:
                    pass
                self.flag[process] = True

    def unlock(self, process):
        self.turn = 1 - process
        self.flag[process] = False

# 使用Dekker算法进行互斥访问的示例
shared_resource = 0
lock = Lock()
dekker = DekkerAlgorithm()

def increment():
    for _ in range(100000):
        lock.acquire()
        shared_resource += 1
        lock.release()

def decrement():
    for _ in range(100000):
        dekker.lock(1)
        shared_resource -= 1
        dekker.unlock(1)

thread1 = Thread(target=increment)
thread2 = Thread(target=decrement)

thread1.start()
thread2.start()

thread1.join()
thread2.join()

print("Final value of shared resource:", shared_resource)

上述代码中，我们使用了Python的线程库`threading`来创建两个线程，分别执行加一和减一操作。通过使用`Lock`类和`DekkerAlgorithm`类实现了对共享资源的互斥访问。