Code examples about multi-process programming in php

This article mainly introduces the PHP multi-process programming method, and analyzes the concepts, usage, related functions and usage techniques of PHP multi-process programming in more detail. Friends in need can refer to the following

Examples of this article Learned PHP multi-process programming. Share it with everyone for your reference, the details are as follows:

Step one:

$ php -m command to check whether php has pcntl and posix extensions installed, if not, install them

Usage scenarios:

1. A large number of time-consuming network operations are required
2. A large number of calculations are required, and the system has multiple CPUs , in order to give users a faster experience, divide a task into several small tasks and finally merge them.

Commonly used functions for multiple processes:

pcntl_alarm — Set an alarm clock signal for the process
pcntl_errno — Alias pcntl_strerror
pcntl_exec —Execute the specified program in the current process space
pcntl_fork—Create a child process and generate a branch (child process) at the current position of the current process. Annotation: fork creates a child process. Both the parent process and the child process continue to execute from the fork position. The difference is that during the execution of the parent process, the return value of fork is the child process number, while the child process gets 0.
pcntl_get_last_error — Retrieve the error number set by the last pcntl function which failed
pcntl_getpriority — Get the priority of any process
pcntl_setpriority — Modify the priority of any process
pcntl_signal_dispatch — Call a handler waiting for a signal
pcntl_signal — Install a signal handler
pcntl_sigprocmask — Set or retrieve blocking signals
pcntl_sigtimedwait — Signal waiting with timeout mechanism
pcntl_sigwaitinfo — Wait for signals
pcntl_strerror — Retrieve the system error message associated with the given errno
pcntl_wait — Wait for or return the child process status of fork
pcntl_waitpid — Wait for or return the child process status of fork
pcntl_wexitstatus — Returns the return code of an interrupted child process
pcntl_wifexited — Checks whether the status code represents a normal exit.
pcntl_wifsignaled — Check whether the child process status code represents an interruption due to a signal
pcntl_wifstopped — Check whether the child process is currently stopped
pcntl_wstopsig — Return the signal that causes the child process to stop
pcntl_wtermsig — Return the signal that causes the child process to interrupt

Example 1:

Copy after login

Example 2: Open multiple child processes to avoid fork flooding

Copy after login

Note:

Use the multi-process function through the pcntl_XXX series of functions. Note: pcntl_XXX can only run in the php CLI (command line) environment. In the web server environment, unpredictable results will occur, please use with caution!

The above is the detailed content of Code examples about multi-process programming in php. For more information, please follow other related articles on the PHP Chinese website!