Python co-process

Co-process, also known as micro-threading, fiber. English name Coroutine. One sentence explains what a thread is: The process is a lightweight thread that is user-state .

The co-process has its own register context and stack. When the schedule is switched, the register context and stack are saved elsewhere, and the previously saved register context and stack are restored when it is cut back.

The greatest advantage is the high execution efficiency of the process. Because the subroutine switch is not a thread switch, but is controlled by the program itself, therefore, there is no thread switching overhead, and multithreading ratio, the more the number of threads, the performance advantage of the association is more obvious.

The second big advantage is that there is no need for a multi-threaded lock mechanism, because there is only one thread, there is no simultaneous write variable conflict, in the process of controlling shared resources without locking, only need to judge the state is good, so the execution efficiency is much higher than multithreading.

Because the co-process is a thread execution, how do you take advantage of multicore CPUs? The simplest method is multi-process + co-progression, which takes full advantage of multicore, and maximizes the high-efficiency of the co-processes, which can achieve very good performance.

ImportQueue,timedefConsumer (name):Print('Start')     whileTrue:new_baozi=yield     #the generator encounters next first returns the value after yield,                            #If you encounter send (value) to assign this value to New_baozi, the first time you encounter a Send (value), the value can only be none        Print('%s Eat No.%d Bun'%(Name,new_baozi))defproducer (): Next (Con) next (con2) n=0 whileN<5: N+=1Print('production of the No.%d Bun'%N) con.send (n) con2.send (n)if __name__=='__main__': Con=consumer ('C1')#Creating a Builder ObjectCon2=consumer ('C2') P=producer ()

What conditions can be called the Association Process:

1. Concurrency must be implemented in only one single thread
2. No lock required to modify shared data
3. The context stack in the user program that holds multiple control flows
4. A coprocessor encounters an IO operation that automatically switches to other co-threads

Python co-process