Process，LWP），是程序执行流的最小单元。一个标准的线程由线程ID，当前指令指针(PC），寄存器集合和堆栈组成。另外，线程是进程中的一个实体，是被系统独立调度和分派的基本单位，线程自己不拥有系统资源，只拥有一点儿在运行中必不可少的资源，但它可与同属一个进程的其它线程共享进程所拥有的全部资源。一个线程可以创建和撤消另一个线程，同一进程中的多个线程之间可以并发执行。由于线程之间的相互制约，致使线程在运行中呈现出间断性。线程也有就绪、阻塞和运行三种基本状态。就绪状态是指线程具备运行的所有条件，逻辑上可以运行，在等待处理机；运行状态是指线程占有处理机正在运行；阻塞状态是指线程在等待一个事件（如某个信号量），逻辑上不可执行。每一个程序都至少有一个线程，若程序只有一个线程，那就是程序本身。线程是程序中一个单一的顺序控制流程。进程内有一个相对独立的、可调度的执行单元，是系统独立调度和分派cpu的基本单位指令运行时的程序的调度单位。在单个程序中同时运行多个线程完成不同的工作，称为多线程。
进程（Process）是计算机中的程序关于某数据集合上的一次运行活动，是系统进行资源分配和调度的基本单位，是 *** 作系统结构的基础。在早期面向进程设计的计算机结构中，进程是程序的基本执行实体；在当代面向线程设计的计算机结构中，进程是线程的容器。程序是指令、数据及其组织形式的描述，进程是程序的实体。
<span >def<span > func(msg):
<span >print<span >(msg)
<span >print(<span >"<span >这是一个线程<span >"<span >)
t=threading.Thread(target=func,args=(<span >"<span >hello world<span >"<span >,))
t.start()
通过继承类的方式创建线程
==</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000;">#</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000;"><a href="https://m.jb51.cc/tag/zheli/" target="_blank" >这里</a>是将threading.Thread中的run<a href="https://www.jb51.cc/tag/fangfa/" target="_blank" >方法</a><a href="https://m.jb51.cc/tag/jinxing/" target="_blank" >进行</a>了重载</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;"><a href="https://www.jb51.cc/tag/s/" target="_blank" >%s</a> is %d</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span>%<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>,self.age))t
=Mythread(<span >"<span >sfencs<span >",19<span >)t.start()
2.线程的并发
单个线程的创建基本没有意义，只是与主线程并发，现在我们看一下多个线程的并发
===</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>) time.sleep(self.second) </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self.age)t1
=Mythread(<span >"<span >sfencs<span >",19,2<span >)t2=Mythread(<span >"<span >Tom<span >",25,5<span >)
t1.start()
t2.start()
这里先同时打印sfencs和Tom，过了两秒打印19，又过3秒打印25.这说明这两个线程是并发的，如果是串行的那么会使用7秒完成
我们可以使用time模块计算时间
===</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>) time.sleep(self.second) </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self.age)time_begin
=<span >time.time()t1
=Mythread(<span >"<span >sfencs<span >",5<span >)t1.start()
t2.start()
time_end=<span >time.time()
<span >print(time_end-time_begin)
'''
sfencsTom0.00103068351745605471925
'''
这里出现一个问题，输出的时间是0.0010306835174560547，而且在年龄之前输出的
原因是计算时间的代码属于主线程，它与两个自己创建的线程并发，所以它提前完成了计算，为了解决这个办法，我们使用join()方法
3.join()
time_begin=t1=Mythread(<span >"<span >sfencs<span >",5<span >)
t1.start()
t2.start()
t1.join()
t2.join()
time_end=<span >time.time()
<span >print(time_end-<span >time_begin)
<span >'''<span >
sfencs
Tom
19
25
5.001618146896362
<span >'''
这样就显然的看出程序并发节约了约2秒钟
除此之外join()方法还有一个参数为阻塞的时间，默认为一直阻塞
4.IO密集型任务和计算密集型任务
IO密集型任务就如上述的例子一样，有阻塞的状态，如sleep()或者等待相关信息，信号时会停用cpu的任务。IO密集型的任务在python中使用多线程能够很好的节约时间完成并发。
计算密集型任务没有等待状态,从上到下执行,没有任何等待
一个线程
</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): i</span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">0 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">while</span> i<100000000<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: i</span>+=1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">time_begin
=<span >time.time()t1=<span >Mythread()
t1.start()
t1.join()
time_end=<span >time.time()
<span >print(time_end-time_begin)#6.194466590881348
两个线程
</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): i</span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">0 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">while</span> i<100000000<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: i</span>+=1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">time_begin
=<span >time.time()t1=<span >Mythread()
t2=<span >Mythread()
t1.start()
t2.start()
t1.join()
t2.join()
time_end=<span >time.time()
<span >print(time_end-time_begin)#11.998910427093506
可见计算密集型任务在python中并发并不能很好的节约时间，和串行差不多（在python以前版本中时间还会比串行多）
可是又有一个问题，我们的电脑不是有多核cpu吗，为什么不能同时两个cpu每个运行一个线程，那样时间就只有串行的一半啊?原因就是接下来讲的GIL
5.GIL
首先需要明确的一点是GIL并不是Python的特性，它是在实现Python解析器(cpython)时所引入的一个概念。就好比C++是一套语言（语法）标准，但是可以用不同的编译器来编译成可执行代码。有名的编译器例如GCC，INTEL C++，Visual C++等。Python也一样，同样一段代码可以通过cpython，PyPy，Psyco等不同的Python执行环境来执行。像其中的JPython就没有GIL。然而因为cpython是大部分环境下默认的Python执行环境。所以在很多人的概念里cpython就是Python，也就想当然的把GIL归结为Python语言的缺陷。所以这里要先明确一点：GIL并不是Python的特性，Python完全可以不依赖于GIL。
那么cpython实现中的GIL又是什么呢？GIL全称Global Interpreter Lock为了避免误导，我们还是来看一下官方给出的解释：
In cpython,the global interpreter lock,or GIL,is a mutex that prevents multiple native threads from executing Python bytecodes at once. This lock is necessary mainly because cpython’s memory management is not thread-safe. (However,since the GIL exists,other features have grown to depend on the guarantees that it enforces.)
GIL就像是一个防止多线程并发的全局锁，GIL的存在导致多线程无法很好的立即多核cpu的并发处理能力。python的多线程在多核cpu上，只对于IO密集型计算产生正面效果；而当有至少有一个cpu密集型线程存在，那么多线程效率会由于GIL而大幅下降。为了避免GIL的影响，可以使用多进程。
这里具体参考href="https://www.cnblogs.com/SuKiWX/p/8804974.HTML" target="_blank">https://www.cnblogs.com/SuKiWX/p/8804974.HTML
6.守护线程setDaemon
当主线程完成时不需要某个子线程完全运行完就要退出程序，那么就可以将这个子线程设置为守护线程，setDaemon(True).
=(time_end-不会显示年龄的输出，因为主线程已经结束。
7.Lock锁
多线程中对同一资源进行处理，有可能会导致数据不安全
<span >def<span > addNum():<span >global<span > num
</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000;">#</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000;">lock.acquire()</span>temp=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">numtime.sleep(</span>0.001<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">)num </span>=temp-1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000;">#</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000;">lock.release()</span><span >
num
thread_List =<span > []
lock=<span >threading.Lock()<span >for i <span >in range(100<span >):
t = threading.Thread(target=<span >addNum)
t.start()
thread_List.append(t)<span >for t <span >in<span > thread_List:
t.join()<span >print(<span >'<span >final num:<span >',num )#final num: 92
这里运行结果并不是0，原因是多个线程在time.sleep()的时候同时拿到了num，所以num是同一个数，解决方法就是加锁
8.死锁与递归锁
==<span >class<span > MyThread(threading.Thread):<span >def<span > run(self):
self.func1()
self.func2()
<span >def<span > func1(self):
mutexA.acquire()
<span >print(<span >'<span >%s 拿到A锁<span >' %<span >self.name)
mutexB.acquire()
<span >print(<span >'<span >%s 拿到B锁<span >' %<span >self.name)
mutexB.release()
mutexA.release()
</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> func2(self): mutexB.acquire() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;"><a href="https://www.jb51.cc/tag/s/" target="_blank" >%s</a> 拿到B锁</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span> %<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>) time.sleep(</span>2<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) mutexA.acquire() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;"><a href="https://www.jb51.cc/tag/s/" target="_blank" >%s</a> 拿到A锁</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span> %<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>) mutexA.release() mutexB.release()<span >for i <span >in range(5<span >):
t=<span >MyThread()
t.start()'''
Thread-1 拿到A锁Thread-1 拿到B锁Thread-1 拿到B锁Thread-2 拿到A锁
这里开了5个线程，可是却阻塞住了，原因是在Thread1拿到B锁，Thread2拿到A锁时，func2中在等待获得A锁，func1中在等待获得B锁，两者都在等待对方释放锁，造成了死锁，使得线程互相阻塞解决方法是使用递归锁Rlock
=<span >class<span > MyThread(threading.Thread):<span >def<span > run(self):
self.func1()
self.func2()
<span >def<span > func1(self):
lock.acquire()
<span >print(<span >'<span >%s 拿到A锁<span >' %<span >self.name)
lock.acquire()
<span >print(<span >'<span >%s 拿到B锁<span >' %<span >self.name)
lock.release()
lock.release()
</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> func2(self): lock.acquire() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;"><a href="https://www.jb51.cc/tag/s/" target="_blank" >%s</a> 拿到B锁</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span> %<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>) time.sleep(</span>2<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) lock.acquire() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;"><a href="https://www.jb51.cc/tag/s/" target="_blank" >%s</a> 拿到A锁</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">'</span> %<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>) lock.release() lock.release()<span >if <span >name == <span >'<span >main<span >'<span >:
<span >for i <span >in range(5<span >):
t=<span >MyThread()
t.start()
<span >'''<span >
Thread-1 拿到A锁
Thread-1 拿到B锁
Thread-1 拿到B锁
Thread-1 拿到A锁
Thread-2 拿到A锁
Thread-2 拿到B锁
Thread-2 拿到B锁
Thread-2 拿到A锁
Thread-4 拿到A锁
Thread-4 拿到B锁
Thread-4 拿到B锁
Thread-4 拿到A锁
Thread-3 拿到A锁
Thread-3 拿到B锁
Thread-3 拿到B锁
Thread-3 拿到A锁
Thread-5 拿到A锁
Thread-5 拿到B锁
Thread-5 拿到B锁
Thread-5 拿到A锁
<span >'''
在Python中为了支持在同一线程中多次请求同一资源，python提供了可重入锁RLock。
这个RLock内部维护着一个Lock和一个counter变量，counter记录了acquire的次数，从而使得资源可以被多次require。直到一个线程所有的acquire都被release，其他的线程才能获得资源
9.信号量
<div >
=threading.Semaphore(3 ===</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): s.acquire() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>) time.sleep(self.second) </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self.age) s.release()t=<span >[]
<span >for i <span >in range(6<span >):
t.append(Mythread(<span >"<span >sfencs<span >",2<span >))
time_begin=<span >time.time()
<span >for i <span >in range(6<span >):
t[i].start()
<span >for i <span >in range(6<span >):
t[i].join()
time_end=<span >time.time()
<span >print(time_end-<span >time_begin)
<span >'''<span >
sfencs
sfencs
sfencs
19
sfencs
19
sfencs
19
sfencs
19
1919
4.003796339035034
<span >'''
如果没有信号量来限制，那么程序完成的时间应该为2秒左右
10.条件变量同步
wait等待notify的通知，当接到通知后，会重新从if accquire()执行
==</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">global</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> count </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">while</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> True: </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> c.acquire(): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span> count>5<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: c.wait() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: count</span>+=1 <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">:生产了一件商品</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) c.notify() c.release() time.sleep(</span>0.5<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">)<span >class<span > consumer(threading.Thread):<span >def <span >init<span >(self):
threading.Thread.<span >init<span >(self)
</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">global</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> count </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">while</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> True: </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> c.acquire(): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span> count<5<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">:我再等一会儿</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) c.wait() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: count</span>-=1 <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">:<a href="https://m.jb51.cc/tag/shiyong/" target="_blank" >使用</a>了一件商品</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) c.notify() c.release() time.sleep(</span>0.5<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">)producer().start()
<span >for i <span >in range(5<span >):
consumer().start()
11.event
事件(event)用于线程间同步和通信。比如线程A要完成某一任务(event)线程B才能执行后面的代码
set() 开始一个事件
wait() 如果未设置set状态会一直等待，否则过
clear() 清除set状态
isSet() 是否设置set状态
<span >class<span > intervIEwer(threading.Thread):<span >def <span >init<span >(self):
threading.Thread.</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800080;"><a href="https://www.jb51.cc/tag/init/" target="_blank" >__init__</a></span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self)</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">我能问你<a href="https://www.jb51.cc/tag/yige/" target="_blank" >一个</a><a href="https://m.jb51.cc/tag/wenti/" target="_blank" >问题</a>吗？</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) event1.set() event2.wait() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">我的<a href="https://m.jb51.cc/tag/wenti/" target="_blank" >问题</a>刚才已经问完了</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) event2.clear() event1.set()<span >class<span > intervIEwee1(threading.Thread):
<span >def <span >init<span >(self):
threading.Thread.</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800080;"><a href="https://www.jb51.cc/tag/init/" target="_blank" >__init__</a></span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">(self)</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): event1.wait() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">你问吧</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) event1.clear() event2.set() event1.wait() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">行吧。。。</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) event1.clear()event1=<span >threading.Event()
event2=<span >threading.Event()
t1 =<span > intervIEwee1()
t2 =<span > intervIEwer()
t1.start()
t2.start()'''
我能问你一个问题吗？你问吧我的问题刚才已经问完了行吧。。。
12.队列queue
说道多线程就不得不提到队列，python中的队列用到了Queue模块,该模块提供了同步的,安全的对序列,包括FIFO（先入先出)队列Queue，liFO（后入先出）队列lifoQueue，和优先级队列PriorityQueue.这些队列都实现了锁原语，能够在多线程中直接使用。可以使用队列来实现线程间的通信
Queue.qsize() 返回队列的大小
Queue.empty() 如果队列为空，返回True,反之False
Queue.full 与 maxsize 大小对应
Queue.get([block[,timeout]])获取队列，timeout等待时间
Queue.get_Nowait() 相当Queue.get(False)
Queue.put(item) 写入队列，timeout等待时间
Queue.put_Nowait(item) 相当Queue.put(item,False)
Queue.task_done() 在完成一项工作之后，Queue.task_done()函数向任务已经完成的队列发送一个信号
Queue.join() 实际上意味着等到队列为空，再执行别的 *** 作
这个程序将之前的一个用队列改写的
==</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">global</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> count </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">while</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> True: </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> c.acquire(): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> count.f<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l(): c.wait() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: count.put(</span>1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">:生产了一件商品</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) c.notify() c.release() time.sleep(</span>0.5<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">)<span >class<span > consumer(threading.Thread):<span >def <span >init<span >(self):
threading.Thread.<span >init<span >(self)
</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">def</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> run(self): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">global</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> count </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">while</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> True: </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> c.acquire(): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">if</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">not</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;"> count.f<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l(): </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">:我再等一会儿</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) c.wait() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">: count.get() </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff;">print</span>(self.<a href="https://m.jb51.cc/tag/name/" target="_blank" >name</a>+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">:<a href="https://m.jb51.cc/tag/shiyong/" target="_blank" >使用</a>了一件商品</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #800000;">"</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">) c.notify() c.release() time.sleep(</span>0.5<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000;">)producer().start()
<span >for i <span >in range(5<span >):
consumer().start() 总结
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