How to implement a basic thread pool with the shell

This article mainly describes how to use bash to implement a basic thread pool.

1. Pre-knowledge

• {}& in Linux means the entire block of code is put into the background execution

• The wait Wait command indicates that all background processes are waiting for the execution to complete

• FIFO Pipeline file

2. Realization of Ideas

There are many ways to implement a process pool, such as creating a file to determine the number of files. In this paper, we use FIFO file to implement thread pool, and use the Read command of Linux in the natural blocking to implement quickly.

3. Concrete implementation

Create process_pool.sh with the following script:

#!/bin/bash  #线程池process_pool () {     #判断输入参数等     if [ $#  -lt 3 ]; then        echo  "$0 process_ Num command [args] "        return 1     fi    _process_num=$1    shift    _func=$1     shift    if [[ ! $_process_num =~ ^[0-9]+ $ ]]; then        echo  "Process_num must be  a number "        return 1    fi     if !type $_func >/dev/null 2>&1; then         echo  "Comannd must be executable"          return 1    fi     #  Create a FIFO pipeline file      fifo= "/tmp/$$.fifo"     mkfifo  $fifo      #创建一个文件描述符号, Associating FD with this file descriptor to this file &NBSP;&NBSP;&NBSP;&NBSP;#{FD} represents a non-display descriptor     exec {FD}<> $fifo     rm  $fifo        #  Create slots      for i in $ (Seq $_process_num); do         echo >& $FD     done       #  Execute specific Commands     for arg in [email protected]; do         read -u  $FD         {             $_func  $arg               echo >& $FD         }&     Done     # wait wait for all background processes to complete     wait      #  Release File descriptor     exec {FD}>&-}   #以下为测试test () {     echo $1    sleep 3    return 0}  process_pool 3  ' Test '  1 2 3 4 5 6 7

Already at the end there is a basic test case, just

SH process_pool.sh

You can see the effect.

This article is from the "xlows" blog, make sure to keep this source http://xlows.blog.51cto.com/5380484/1773678

How to implement a basic thread pool with the shell