PHP Extension: php-affinity

Php-affinity by setting CPU affinity, you can bind a process to a CPU core. In general, we may want to modify the CPU affinity of a process in the following scenarios:

• Frequent parallel operations

• Thread Scalability Testing (simulates linear scaling by increasing the number of CPU cores)

• Run time-sensitive, decisive process

Open source software, such as Nginx,swoole, provides a way to set CPU affinity. Nginx officially recommends that the number of workers equal to the number of CPU cores is also to bind a process to a CPU core while avoiding the overhead of process switching.

PHP itself does not provide a function to set CPU affinity, which we can implement in two ways:

• Invoking system commands to modify the current process CPU affinity

• Write PHP extensions to encapsulate system calls.

Php-affinity is a php extension written using C, project address: https://github.com/huyanping/php-affinity

  /** * Set CPU affinity * * @param $cpu _id * @return BOOL */functionsetaffinity ($cpu _id) {$num = getc                        Pucores ();                        if ($cpu _id>= $num) {returnfalse;                        } $set = System_call ($cpu _id);                        if ($set = = =-1) {returnfalse;                    } returntrue;                     }/** * Get CPU affinity * * @return BOOL */functiongetaffinity () {$cpu _id= Syst                        Em_call ();                        if ($cpu _id===-1) {returnfalse;    } return$cpu_id;                }/** * Get number of C PU * * @return BOOL */Functiongetcpucores (                        ) {$nums = System_call ();                        if ($nums = = =-1) {returnfalse;                    } return$nums; }

The following three functions are available:

setaffinity– Setting CPU Affinity

getaffinity– Getting CPU Affinity

getcpucores– getting the number of CPU cores

The API is as follows:

Reference documents:

Https://zh.wikipedia.org/wiki/%E5%A4%84%E7%90%86%E5%99%A8%E4%BA%B2%E5%92%8C%E6%80%A7

Http://www.ibm.com/developerworks/cn/linux/l-affinity.html

Http://www.cnblogs.com/LubinLew/p/cpu_affinity.html

Project home:http://www.open-open.com/lib/view/home/1448371981438

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