python 生产者消费者

生产者消费者问题是一个经典的多线程同步问题，其中生产者线程负责生产数据并将其放入缓冲区，而消费者线程则负责从缓冲区中取出数据并进行消费。以下是一个简单的 Python 生产者消费者示例代码：

import threading
import time

# 缓冲区大小
BUFFER_SIZE = 10

# 生产者线程
class ProducerThread(threading.Thread):
    def __init__(self, buffer):
        threading.Thread.__init__(self)
        self.buffer = buffer

    def run(self):
        for i in range(20):
            item = "item %d" % i
            self.buffer.put(item)
            print("Produced:", item)
            time.sleep(0.5)

# 消费者线程
class ConsumerThread(threading.Thread):
    def __init__(self, buffer):
        threading.Thread.__init__(self)
        self.buffer = buffer

    def run(self):
        while True:
            item = self.buffer.get()
            print("Consumed:", item)
            time.sleep(1)

# 缓冲区
class Buffer:
    def __init__(self):
        self.items = []
        self.lock = threading.Lock()
        self.full = threading.Semaphore(0)
        self.empty = threading.Semaphore(BUFFER_SIZE)

    def put(self, item):
        self.empty.acquire()
        self.lock.acquire()
        self.items.append(item)
        self.lock.release()
        self.full.release()

    def get(self):
        self.full.acquire()
        self.lock.acquire()
        item = self.items.pop(0)
        self.lock.release()
        self.empty.release()
        return item

# 测试代码
if __name__ == "__main__":
    buffer = Buffer()
    producer_thread = ProducerThread(buffer)
    consumer_thread = ConsumerThread(buffer)
    producer_thread.start()
    consumer_thread.start()