1 import queue
2 import threading
3 import contextlib
4 import time
5
6 StopEvent = object()
7
8
9 class ThreadPool(object):
10
11 def __init__(self, max_num):
12
13 self.q = queue.Queue()
14 #最多创建线程数
15 self.max_num = max_num
16 self.cancel = False
17 self.terminal = False
18 #真实创建的线程列表
19 self.generate_list = []
20 #空闲的线程列表
21 self.free_list = []
22
23 def run(self, func, args, callback=None):
24 """
25 线程池执行一个任务
26 :param func: 任务函数
27 :param args: 任务函数所需参数
28 :param callback: 任务执行失败或成功后执行的回调函数，回调函数有两个参数1、任务函数执行状态；2、任务函数返回值（默认为None，即：不执行回调函数）
29 :return: 如果线程池已经终止，则返回True否则None
30 """
31 if self.cancel:
32 return
33 if len(self.free_list) == 0 and len(self.generate_list) < self.max_num:
34 self.generate_thread()
35 w = (func, args, callback,)
36 self.q.put(w)
37
38 def generate_thread(self):
39 """
40 创建一个线程
41 """
42 t = threading.Thread(target=self.call)
43 t.start()
44
45 def call(self):
46 """
47 循环去获取任务函数并执行任务函数
48 """
49 current_thread = threading.currentThread()
50 self.generate_list.append(current_thread)
51
52 event = self.q.get()
53 while event != StopEvent:
54
55 func, arguments, callback = event
56 try:
57 result = func(*arguments)
58 success = True
59 except Exception as e:
60 success = False
61 result = None
62
63 if callback is not None:
64 try:
65 callback(success, result)
66 except Exception as e:
67 pass
68
69 with self.worker_state(self.free_list, current_thread):
70 if self.terminal:
71 event = StopEvent
72 else:
73 event = self.q.get()
74 else:
75
76 self.generate_list.remove(current_thread)
77
78 def close(self):
79 """
80 执行完所有的任务后，所有线程停止
81 """
82 self.cancel = True
83 full_size = len(self.generate_list)
84 while full_size:
85 self.q.put(StopEvent)
86 full_size -= 1
87
88 def terminate(self):
89 """
90 无论是否还有任务，终止线程
91 """
92 self.terminal = True
93
94 while self.generate_list:
95 self.q.put(StopEvent)
96
97 self.q.queue.clear()
98
99 @contextlib.contextmanager
100 def worker_state(self, state_list, worker_thread):
101 """
102 用于记录线程中正在等待的线程数
103 """
104 state_list.append(worker_thread)
105 try:
106 yield
107 finally:
108 state_list.remove(worker_thread)
109
110
111
112 pool = ThreadPool(5)
113
114 def callback(status, result):
115 # status, execute action status
116 # result, execute action return value
117 pass
118
119
120 def action(i):
121 print(i)
122
123 for i in range(30):
124 ret = pool.run(action, (i,), callback)
125
126 time.sleep(5)
127
128 print(len(pool.generate_list), len(pool.free_list))
129 print(len(pool.generate_list), len(pool.free_list))
130 # pool.close()
131 pool.terminate()
