update

Author: wangchao

docs/chapter4/crawling_the_web_using_the_concurrent_futures_module.md

@@ -151,13 +151,16 @@ def crawl_task(url):
 raise
 finally:
 return (url, links)
-
-with ThreadPoolExecutor(max_workers=3) as group_link_threads:
-for i inrange(urls.qsize()):
- group_link_threads.submit(group_urls_task, urls)
 
-with ThreadPoolExecutor(max_workers=3) as crawler_link_threads:
- future_tasks ={
- crawler_link_threads.submit(crawl_task, url): url 
-for url in result_dict.keys()}
+
+if__name__=="__main__":
+
+with ThreadPoolExecutor(max_workers=3) as group_link_threads:
+for i inrange(urls.qsize()):
+ group_link_threads.submit(group_urls_task, urls)
+
+with ThreadPoolExecutor(max_workers=3) as crawler_link_threads:
+ future_tasks ={
+ crawler_link_threads.submit(crawl_task, url): url 
+for url in result_dict.keys()}
 ```

docs/chapter4/using_threading_to_obtain_the_Fibonacci_series_term_with_multiple_inputs.md

@@ -129,3 +129,69 @@ $ python temp.py
 请注意，首先创建并初始化 `fibonacci_task` 线程，然后它们进入等待状态。 同时，创建 `queue_task` 并填充 `shared_queue`。 最后，`queue_task` 通知 `fibonacci_task` 线程它们可以执行它们的任务。
 
 请注意，`fibonacci_task` 线程的执行不遵循顺序逻辑，每次执行的顺序可能不同。 这就是使用线程的一个特点：**非确定性**(non-determinism)。
+
+## 完整例子
+
+译者注:
+
+```python
+
+#coding: utf-8
+
+import logging, threading
+
+from queue import Queue
+
+logger = logging.getLogger()
+logger.setLevel(logging.DEBUG)
+formatter = logging.Formatter('%(asctime)s - %(message)s')
+
+ch = logging.StreamHandler()
+ch.setLevel(logging.DEBUG)
+ch.setFormatter(formatter)
+logger.addHandler(ch)
+
+fibo_dict ={}
+shared_queue = Queue()
+input_list = [3, 10, 5, 7]
+
+queue_condition = threading.Condition()
+
+def fibonacci_task(condition):
+ with condition:
+whileshared_queue.empty():
+ logger.info("[%s] - waiting for elements in queue.." % threading.current_thread().name)
+condition.wait()
+ else:
+ value = shared_queue.get()
+ a, b = 0, 1
+foritemin range(value):
+ a, b = b, a + b
+ fibo_dict[value] = a 
+shared_queue.task_done()
+ logger.debug("[%s] fibonacci of key [%d] with result [%d]" % (threading.current_thread().name, value, fibo_dict[value]))
+
+def queue_task(condition):
+ logging.debug('Starting queue_task...')
+ with condition:
+foritemin input_list:
+ shared_queue.put(item)
+ logging.debug("Notifying fibonacci_task threadsthat the queue is ready to consume..")
+condition.notify_all()
+
+
+
+
+if __name__ == "__main__":
+ threads = [
+ threading.Thread(daemon=True, target=fibonacci_task,args=(queue_condition,)) 
+foriin range(4)
+ ]
+
+ [thread.start() forthreadin threads]
+
+ prod = threading.Thread(name='queue_task_thread', daemon=True, target=queue_task, args=(queue_condition,))
+prod.start()
+
+ [thread.join() forthreadin threads]
+```