figure:last-child { margin-bottom: 0.5rem; }
#write ol, #write ul { position: relative; }
img { max-width: 100%; vertical-align: middle; }
button, input, select, textarea { color: inherit; font: inherit; }
input[type="checkbox"], input[type="radio"] { line-height: normal; padding: 0px; }
*, ::after, ::before { box-sizing: border-box; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p, #write pre { width: inherit; }
#write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write p { position: relative; }
p { line-height: inherit; }
h1, h2, h3, h4, h5, h6 { break-after: avoid-page; break-inside: avoid; orphans: 2; }
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h1 { font-size: 2rem; }
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h5 { font-size: 1.2rem; }
h6 { font-size: 1rem; }
.md-math-block, .md-rawblock, h1, h2, h3, h4, h5, h6, p { margin-top: 1rem; margin-bottom: 1rem; }
.hidden { display: none; }
.md-blockmeta { color: rgb(204, 204, 204); font-weight: 700; font-style: italic; }
a { cursor: pointer; }
sup.md-footnote { padding: 2px 4px; background-color: rgba(238, 238, 238, 0.7); color: rgb(85, 85, 85); border-radius: 4px; cursor: pointer; }
sup.md-footnote a, sup.md-footnote a:hover { color: inherit; text-transform: inherit; text-decoration: inherit; }
#write input[type="checkbox"] { cursor: pointer; width: inherit; height: inherit; }
figure { overflow-x: auto; margin: 1.2em 0px; max-width: calc(100% + 16px); padding: 0px; }
figure > table { margin: 0px !important; }
tr { break-inside: avoid; break-after: auto; }
thead { display: table-header-group; }
table { border-collapse: collapse; border-spacing: 0px; width: 100%; overflow: auto; break-inside: auto; text-align: left; }
table.md-table td { min-width: 32px; }
.CodeMirror-gutters { border-right: 0px; background-color: inherit; }
.CodeMirror-linenumber { user-select: none; }
.CodeMirror { text-align: left; }
.CodeMirror-placeholder { opacity: 0.3; }
.CodeMirror pre { padding: 0px 4px; }
.CodeMirror-lines { padding: 0px; }
div.hr:focus { cursor: none; }
#write pre { white-space: pre-wrap; }
#write.fences-no-line-wrapping pre { white-space: pre; }
#write pre.ty-contain-cm { white-space: normal; }
.CodeMirror-gutters { margin-right: 4px; }
.md-fences { font-size: 0.9rem; display: block; break-inside: avoid; text-align: left; overflow: visible; white-space: pre; background: inherit; position: relative !important; }
.md-diagram-panel { width: 100%; margin-top: 10px; text-align: center; padding-top: 0px; padding-bottom: 8px; overflow-x: auto; }
#write .md-fences.mock-cm { white-space: pre-wrap; }
.md-fences.md-fences-with-lineno { padding-left: 0px; }
#write.fences-no-line-wrapping .md-fences.mock-cm { white-space: pre; overflow-x: auto; }
.md-fences.mock-cm.md-fences-with-lineno { padding-left: 8px; }
.CodeMirror-line, twitterwidget { break-inside: avoid; }
.footnotes { opacity: 0.8; font-size: 0.9rem; margin-top: 1em; margin-bottom: 1em; }
.footnotes + .footnotes { margin-top: 0px; }
.md-reset { margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: top; background: 0px 0px; text-decoration: none; text-shadow: none; float: none; position: static; width: auto; height: auto; white-space: nowrap; cursor: inherit; -webkit-tap-highlight-color: transparent; line-height: normal; font-weight: 400; text-align: left; box-sizing: content-box; direction: ltr; }
li div { padding-top: 0px; }
blockquote { margin: 1rem 0px; }
li .mathjax-block, li p { margin: 0.5rem 0px; }
li { margin: 0px; position: relative; }
blockquote > :last-child { margin-bottom: 0px; }
blockquote > :first-child, li > :first-child { margin-top: 0px; }
.footnotes-area { color: rgb(136, 136, 136); margin-top: 0.714rem; padding-bottom: 0.143rem; white-space: normal; }
#write .footnote-line { white-space: pre-wrap; }
@media print {
body, html { border: 1px solid transparent; height: 99%; break-after: avoid; break-before: avoid; }
#write { margin-top: 0px; padding-top: 0px; border-color: transparent !important; }
.typora-export * { -webkit-print-color-adjust: exact; }
html.blink-to-pdf { font-size: 13px; }
.typora-export #write { padding-left: 32px; padding-right: 32px; padding-bottom: 0px; break-after: avoid; }
.typora-export #write::after { height: 0px; }
}
.footnote-line { margin-top: 0.714em; font-size: 0.7em; }
a img, img a { cursor: pointer; }
pre.md-meta-block { font-size: 0.8rem; min-height: 0.8rem; white-space: pre-wrap; background: rgb(204, 204, 204); display: block; overflow-x: hidden; }
p > .md-image:only-child:not(.md-img-error) img, p > img:only-child { display: block; margin: auto; }
p > .md-image:only-child { display: inline-block; width: 100%; }
#write .MathJax_Display { margin: 0.8em 0px 0px; }
.md-math-block { width: 100%; }
.md-math-block:not(:empty)::after { display: none; }
[contenteditable="true"]:active, [contenteditable="true"]:focus { outline: 0px; box-shadow: none; }
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.md-toc-content { position: relative; margin-left: 0px; }
.md-toc-content::after, .md-toc::after { display: none; }
.md-toc-item { display: block; color: rgb(65, 131, 196); }
.md-toc-item a { text-decoration: none; }
.md-toc-inner:hover { text-decoration: underline; }
.md-toc-inner { display: inline-block; cursor: pointer; }
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.md-toc-h2 .md-toc-inner { margin-left: 2em; }
.md-toc-h3 .md-toc-inner { margin-left: 4em; }
.md-toc-h4 .md-toc-inner { margin-left: 6em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 .md-toc-inner { margin-left: 10em; }
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.md-toc-h3 .md-toc-inner { margin-left: 3.5em; }
.md-toc-h4 .md-toc-inner { margin-left: 5em; }
.md-toc-h5 .md-toc-inner { margin-left: 6.5em; }
.md-toc-h6 .md-toc-inner { margin-left: 8em; }
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.footnote-line a:not(.reversefootnote) { color: inherit; }
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kbd { margin: 0px 0.1em; padding: 0.1em 0.6em; font-size: 0.8em; color: rgb(36, 39, 41); background: rgb(255, 255, 255); border: 1px solid rgb(173, 179, 185); border-radius: 3px; box-shadow: rgba(12, 13, 14, 0.2) 0px 1px 0px, rgb(255, 255, 255) 0px 0px 0px 2px inset; white-space: nowrap; vertical-align: middle; }
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a.md-print-anchor { white-space: pre !important; border-width: initial !important; border-style: none !important; border-color: initial !important; display: inline-block !important; position: absolute !important; width: 1px !important; right: 0px !important; outline: 0px !important; background: 0px 0px !important; text-decoration: initial !important; text-shadow: initial !important; }
.md-inline-math .MathJax_SVG .noError { display: none !important; }
.html-for-mac .inline-math-svg .MathJax_SVG { vertical-align: 0.2px; }
.md-math-block .MathJax_SVG_Display { text-align: center; margin: 0px; position: relative; text-indent: 0px; max-width: none; max-height: none; min-height: 0px; min-width: 100%; width: auto; overflow-y: hidden; display: block !important; }
.MathJax_SVG_Display, .md-inline-math .MathJax_SVG_Display { width: auto; margin: inherit; display: inline-block !important; }
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.MathJax_SVG { display: inline; font-style: normal; font-weight: 400; line-height: normal; zoom: 90%; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; }
.MathJax_SVG * { transition: none 0s ease 0s; }
.MathJax_SVG_Display svg { vertical-align: middle !important; margin-bottom: 0px !important; margin-top: 0px !important; }
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[lang="mermaid"] svg, [lang="flow"] svg { max-width: 100%; height: auto; }
[lang="mermaid"] .node text { font-size: 1rem; }
table tr th { border-bottom: 0px; }
video { max-width: 100%; display: block; margin: 0px auto; }
iframe { max-width: 100%; width: 100%; border: none; }
.highlight td, .highlight tr { border: 0px; }

.CodeMirror { height: auto; }
.CodeMirror.cm-s-inner { background: inherit; }
.CodeMirror-scroll { overflow: auto hidden; z-index: 3; }
.CodeMirror-gutter-filler, .CodeMirror-scrollbar-filler { background-color: rgb(255, 255, 255); }
.CodeMirror-gutters { border-right: 1px solid rgb(221, 221, 221); background: inherit; white-space: nowrap; }
.CodeMirror-linenumber { padding: 0px 3px 0px 5px; text-align: right; color: rgb(153, 153, 153); }
.cm-s-inner .cm-keyword { color: rgb(119, 0, 136); }
.cm-s-inner .cm-atom, .cm-s-inner.cm-atom { color: rgb(34, 17, 153); }
.cm-s-inner .cm-number { color: rgb(17, 102, 68); }
.cm-s-inner .cm-def { color: rgb(0, 0, 255); }
.cm-s-inner .cm-variable { color: rgb(0, 0, 0); }
.cm-s-inner .cm-variable-2 { color: rgb(0, 85, 170); }
.cm-s-inner .cm-variable-3 { color: rgb(0, 136, 85); }
.cm-s-inner .cm-string { color: rgb(170, 17, 17); }
.cm-s-inner .cm-property { color: rgb(0, 0, 0); }
.cm-s-inner .cm-operator { color: rgb(152, 26, 26); }
.cm-s-inner .cm-comment, .cm-s-inner.cm-comment { color: rgb(170, 85, 0); }
.cm-s-inner .cm-string-2 { color: rgb(255, 85, 0); }
.cm-s-inner .cm-meta { color: rgb(85, 85, 85); }
.cm-s-inner .cm-qualifier { color: rgb(85, 85, 85); }
.cm-s-inner .cm-builtin { color: rgb(51, 0, 170); }
.cm-s-inner .cm-bracket { color: rgb(153, 153, 119); }
.cm-s-inner .cm-tag { color: rgb(17, 119, 0); }
.cm-s-inner .cm-attribute { color: rgb(0, 0, 204); }
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.cm-s-inner .cm-quote, .cm-s-inner.cm-quote { color: rgb(0, 153, 0); }
.cm-s-inner .cm-hr, .cm-s-inner.cm-hr { color: rgb(153, 153, 153); }
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.cm-constant { color: rgb(38, 139, 210); }
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.CodeMirror-scrollbar-filler { right: 0px; bottom: 0px; }
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.CodeMirror pre { border-radius: 0px; border-width: 0px; background: 0px 0px; font-family: inherit; font-size: inherit; margin: 0px; white-space: pre; overflow-wrap: normal; color: inherit; z-index: 2; position: relative; overflow: visible; }
.CodeMirror-wrap pre { overflow-wrap: break-word; white-space: pre-wrap; word-break: normal; }
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.CodeMirror-linebackground { position: absolute; left: 0px; right: 0px; top: 0px; bottom: 0px; z-index: 0; }
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.CodeMirror-measure { position: absolute; width: 100%; height: 0px; overflow: hidden; visibility: hidden; }
.CodeMirror-measure pre { position: static; }
.CodeMirror div.CodeMirror-cursor { position: absolute; visibility: hidden; border-right: none; width: 0px; }
.CodeMirror div.CodeMirror-cursor { visibility: hidden; }
.CodeMirror-focused div.CodeMirror-cursor { visibility: inherit; }
.cm-searching { background: rgba(255, 255, 0, 0.4); }
@media print {
.CodeMirror div.CodeMirror-cursor { visibility: hidden; }
}

:root { --side-bar-bg-color: #fafafa; --control-text-color: #777; }
html { font-size: 16px; }
body { font-family: "Open Sans", "Clear Sans", "Helvetica Neue", Helvetica, Arial, sans-serif; color: rgb(51, 51, 51); line-height: 1.6; }
#write { max-width: 860px; margin: 0px auto; padding: 30px 30px 100px; }
#write > ul:first-child, #write > ol:first-child { margin-top: 30px; }
a { color: rgb(65, 131, 196); }
h1, h2, h3, h4, h5, h6 { position: relative; margin-top: 1rem; margin-bottom: 1rem; font-weight: bold; line-height: 1.4; cursor: text; }
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h1 tt, h1 code { font-size: inherit; }
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h3 tt, h3 code { font-size: inherit; }
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h1 { padding-bottom: 0.3em; font-size: 2.25em; line-height: 1.2; border-bottom: 1px solid rgb(238, 238, 238); }
h2 { padding-bottom: 0.3em; font-size: 1.75em; line-height: 1.225; border-bottom: 1px solid rgb(238, 238, 238); }
h3 { font-size: 1.5em; line-height: 1.43; }
h4 { font-size: 1.25em; }
h5 { font-size: 1em; }
h6 { font-size: 1em; color: rgb(119, 119, 119); }
p, blockquote, ul, ol, dl, table { margin: 0.8em 0px; }
li > ol, li > ul { margin: 0px; }
hr { height: 2px; padding: 0px; margin: 16px 0px; background-color: rgb(231, 231, 231); border: 0px none; overflow: hidden; box-sizing: content-box; }
li p.first { display: inline-block; }
ul, ol { padding-left: 30px; }
ul:first-child, ol:first-child { margin-top: 0px; }
ul:last-child, ol:last-child { margin-bottom: 0px; }
blockquote { border-left: 4px solid rgb(223, 226, 229); padding: 0px 15px; color: rgb(119, 119, 119); }
blockquote blockquote { padding-right: 0px; }
table { padding: 0px; word-break: initial; }
table tr { border-top: 1px solid rgb(223, 226, 229); margin: 0px; padding: 0px; }
table tr:nth-child(2n), thead { background-color: rgb(248, 248, 248); }
table tr th { font-weight: bold; border-width: 1px 1px 0px; border-top-style: solid; border-right-style: solid; border-left-style: solid; border-top-color: rgb(223, 226, 229); border-right-color: rgb(223, 226, 229); border-left-color: rgb(223, 226, 229); border-image: initial; border-bottom-style: initial; border-bottom-color: initial; margin: 0px; padding: 6px 13px; }
table tr td { border: 1px solid rgb(223, 226, 229); margin: 0px; padding: 6px 13px; }
table tr th:first-child, table tr td:first-child { margin-top: 0px; }
table tr th:last-child, table tr td:last-child { margin-bottom: 0px; }
.CodeMirror-lines { padding-left: 4px; }
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Python学习day36-并发编程(2)

Process的一些常用方法和属性

join

join的主要用法是在于可以让主进程等待子进程运行完后,再执行下面的语句.要注意的一点是,主进程在等待,但是子进程在正常运行.

下面是join一些简单用法,包括串行,并行以及并行的优化

 
 
 
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118
 
 
 
 
1
from multiprocessing import Process
2
import time
3
​
4
def foo():
5
print('进程start')
6
time.sleep(2)
7
print('进程end')
8
if __name__ == '__main__':
9
p = Process(target=foo)
10
p.start()
11
time.sleep(5)
12
p.join()  # 要等待该子进程全部执行完才会继续向下运行,主进程在等待,子进程在运行,内部会调用wait(),回收其子进程的pid号
13
print('主')
14
    
15
    
16
# 输出结果为:
17
# 进程start
18
# 进程end
19
# 主
20
​
21
​
22
​
23
# 串行,开辟内存空间要多费时间
24
def foo(x):
25
print(f'{x}进程start')
26
time.sleep(x)
27
print(f'{x}进程end')
28
if __name__ == '__main__':
29
p = Process(target=foo, args=(3,))
30
p2 = Process(target=foo, args=(2,))
31
p3 = Process(target=foo, args=(1,))
32
start = time.time()
33
p.start()
34
p.join()
35
p2.start()
36
p2.join()
37
p3.start()
38
p3.join()
39
# time.sleep(5)
40
end = time.time()
41
print(f'{end-start}')
42
print('主')
43
# 结果为:
44
# 3进程start
45
# 3进程end
46
# 2进程start
47
# 2进程end
48
# 1进程start
49
# 1进程end
50
# 6.7584381103515625这个时间不是绝对的,会根据所在机器的性能变化
51
# 主
52
​
53
​
54
​
55
# 并行,真正的同时运行
56
def foo(x):
57
print(f'{x}进程start')
58
time.sleep(x)
59
print(f'{x}进程end')
60
if __name__ == '__main__':
61
p = Process(target=foo, args=(10,))
62
p2 = Process(target=foo, args=(2,))
63
p3 = Process(target=foo, args=(1,))
64
start = time.time()
65
p.start()
66
p2.start()
67
p3.start()
68
# time.sleep(5)
69
p.join()  
70
p2.join()
71
p3.join()
72
end = time.time()
73
print(f'{end-start}')
74
print('主')
75
​
76
# 结果为:
77
# 2进程start
78
# 3进程start
79
# 1进程start
80
# 1进程end
81
# 2进程end
82
# 3进程end
83
# 3.3003978729248047
84
# 主
85
​
86
​
87
# 上述这种并行的发生看起来非常的麻烦,所以我们其实可以用一个循环把下面重复性的创建进程以及join暂停进程都放到循环里,简化代码.
88
# 并行的优化
89
​
90
def foo(x):
91
print(f'{x}进程start')
92
time.sleep(x)
93
print(f'{x}进程end')
94
​
95
​
96
if __name__ == '__main__':
97
start = time.time()
98
p_list = []# 创建一个p_list列表用来接收创建的子进程
99
for i in range(1, 4):
100
p = Process(target=foo, args=(i,))
101
p.start()
102
p_list.append(p)
103
for p in p_list:#将列表里的子进程一一拿出来循环,然后通过join分别暂停主进程,从而达到并行的目的
104
p.join()
105
end = time.time()
106
print(end - start)
107
print('主')
108
    
109
    
110
# 结果为:
111
# 2进程start
112
# 1进程start
113
# 3进程start
114
# 1进程end
115
# 2进程end
116
# 3进程end
117
# 3.275794744491577
118
# 主
 
 

获取当前进程pid和父进程pid

获取当前进程pid的常用方式有两种,分别是:

os.getpid(),这是os模块所带有的方法,可以查看当前进程的pid号

os.getppid(),注意这里是ppid,多了一个p,是查看当前进程的父进程的pid号

子进程对象.pid

 
 
 
xxxxxxxxxx
30
 
 
 
 
1
from multiprocessing import Process, current_process  # 获取当前进程的对象
2
​
3
import time, os
4
​
5
​
6
def task():
7
print('子进程start')
8
print('在子进程中查看自身的pid', current_process().pid)
9
print('在子进程中查看自身的pid', os.getpid())
10
print('在子进程中查看父进程的pid', os.getppid())
11
time.sleep(200)
12
print('子进程end')
13
​
14
​
15
if __name__ == '__main__':
16
p = Process(target=task)
17
p.start()
18
print('在主进程查看子进程的pid', p.pid)  # 一定写在子进程启动之后,即start之后
19
print('主进程pid', os.getpid())
20
print('主')
21
    
22
    
23
# 运行结果为:(这里pid每次执行都是不一样的,都是重新分配的)
24
# 在主进程查看子进程的pid 9964
25
# 主进程pid 11584
26
# 主
27
# 子进程start
28
# 在子进程中查看自身的pid 9964
29
# 在子进程中查看自身的pid 9964
30
# 在子进程中查看父进程的pid 11584
 
 

name和is_alive

name() 进程名称,可以手动定义

is_alive() 判断进程是否还存在,只要运行完了就返回false,即便是僵尸进程也是false

 
 
 
xxxxxxxxxx
31
 
 
 
 
1
from multiprocessing import Process, current_process
2
import time
3
​
4
​
5
def foo():
6
print('进程start')
7
print(current_process().name)
8
time.sleep(2)
9
print('进程end')
10
​
11
​
12
if __name__ == '__main__':
13
p = Process(target=foo, name='nick')
14
# p2 = Process(target=foo, name='jack')
15
# p3 = Process(target=foo, name='mata')
16
p.start()
17
# p2.start()
18
# p3.start()
19
print(p.is_alive())# 判定进程是否还活着,返回值是True活着False
20
print(p.name)# 输出进程的名字,也可以是自身赋予的值,如果自己没有赋值系统默认的就是Process-数字
21
# print(p2.name)
22
# print(p3.name)
23
​
24
    
25
# 结果是:
26
# True
27
# nick
28
# 进程start
29
# nick
30
# 进程end
31
​
 
 

terminate

手动结束子进程,但其实只是给操作系统发送了一个关闭进程的请求,需要时间才能完成,推荐在后面加上p.join()来实时判断进程是否已经结束了,也就是说进程只有执行完了才会进行下面的语句.

 
 
 
xxxxxxxxxx
18
 
 
 
 
1
from multiprocessing import Process, current_process
2
import time
3
​
4
​
5
def foo():
6
print('进程start')
7
print(current_process().name)
8
time.sleep(2)
9
print('进程end')
10
​
11
​
12
if __name__ == '__main__':
13
p = Process(target=foo, name='nick')
14
p.start()
15
p.terminate()
16
# p.join()
17
print(p.is_alive())
18
# print(p.name)
 
 

daemon

守护进程(本质就是一个子进程)

  1. 守护进程会在父进程结束之后就随之结束(实际上父进程代码执行完了守护进程就会结束,而不是父进程完全结束)
  2. 守护进程不能创建子进程
 
 
 
x
 
 
 
 
1
from multiprocessing import Process, current_process
2
import time
3
​
4
​
5
def foo():
6
print('守护进程start', time.time())
7
time.sleep(3)
8
print('守护进程end', time.time())
9
​
10
​
11
def task():
12
print('子进程start', time.time())
13
time.sleep(5)
14
print('子进程end', time.time())
15
​
16
​
17
if __name__ == '__main__':
18
p = Process(target=foo, name='nick')
19
p2 = Process(target=task, name='nick')
20
p.daemon = True  # 定义为守护进程,必须要在start之前定义
21
p.start()
22
p2.start()
23
time.sleep(2)
24
print('主', time.time())
25
# 结果为:
26
# 守护进程start 1568278460.6168563
27
# 子进程start 1568278460.6188455
28
# 主 1568278462.376258
29
# 子进程end 1568278465.6189692
30
​
31
​
32
# 可以看到上述例程的结果里没有守护进程结束的输出语句,因为父进程已经结束了,所以守护进程跟随父进程结束了,后面的就没有打印.
 
 

Tips:抢票软件的原理

先来语言分析一波,抢票的总体流程是怎样的,12306的数据库里肯定有实时的票数以及票价,我们购买的时候呢,就要发一个请求,包括查询和购买都要发请求,然后12306的服务器给我们返回数据库里的票数,可是我们都知道,网络是有延迟的,数据传输也是需要时间的,所以很可能同时有很多人,同时查询这个车次的票,然后得到还有一张票的消息(比如),然后这些人都点击购买,那么12306会把这个票给哪个用户呢?

其实这种情况下我们如果用并行进程的概念是行不通的,因为延迟的情况下就有可能很多人都买到了这张票,可是实际情况是不可能的,所以这里为了数据的安全以及逻辑的缜密,我们就要牺牲效率,转而用串行的方法来处理这个事情,尽管效率会慢很多,但是不会出现一张票同时卖给很多人的情况.也就是说用join方法来实现串行.

例程如下:

 
 
 
x
 
 
1
# 这里我们需要在文件的同目录创建一个db.txt文件
2
# 在文件里写{"count": 1}
3
from multiprocessing import Process, current_process
4
import time
5
import json
6
import os
7
​
8
​
9
def search():
10
    time.sleep(1)  # 模拟网络io
11
    with open('db.txt', 'rt', encoding='utf-8')as f:
12
        res = json.load(f)
13
        print(f'还剩{res["count"]}张票')
14
​
15
​
16
def get():
17
    with open('db.txt', 'rt', encoding='utf-8')as f:
18
        res = json.load(f)
19
        print(f'还剩{res["count"]}张票')
20
    time.sleep(1)  # 模拟网络io
21
    if res['count'] > 0:
22
        res['count'] -= 1
23
        with open('db.txt', 'wt', encoding='utf-8')as f:
24
            json.dump(res, f)
25
            f.flush()
26
            print(f'{os.getpid()}抢票成功')
27
            time.sleep(1)  # 模拟网络io
28
​
29
    else:
30
        print('票已经售空!~!~!~!~!~!~!~!')
31
    # current_process().terminate()
32
​
33
​
 
 
34
def task():
35
    #search()
36
    get()
37
​
38
​
39
if __name__ == '__main__':
40
    for i in range(5):
41
        p = Process(target=task)
42
        p.start()
43
        p.join()
44
# 输出结果为:
45
# 还剩1张票
46
# 11576抢票成功
47
# 还剩0张票
48
# 票已经售空!~!~!~!~!~!~!~!
49
# 还剩0张票
50
# 票已经售空!~!~!~!~!~!~!~!
51
# 还剩0张票
52
# 票已经售空!~!~!~!~!~!~!~!
53
# 还剩0张票
54
# 票已经售空!~!~!~!~!~!~!~!
55
​
 
 

当然实际的抢票软件肯定做了更多的优化,不会这么简单,但是大概逻辑是差不多的.

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