深入理解PHP高性能框架中Workerman守護(hù)進(jìn)程原理

[ manongsen@root  phpwork]$ php index.php
[parent] process id: 61052, parent process id: 8243, process group id: 61052, session id: 8243
[parent1] process id: 61052, parent process id: 8243, process group id: 61052, session id: 8243 exited the process
[child1] process id: 61053, parent process id: 61052, process group id: 61052, session id: 8243
[child1] process id: 61053, parent process id: 61052, process group id: 61053, session id: 61053
[parent2] process id: 61053, parent process id: 61052, process group id: 61053, session id: 61053 exited the process
[child2] process id: 61054, parent process id: 61053, process group id: 61053, session id: 61053. this process is retained

[ manongsen@root  phpwork]$ ps aux | grep index.php
root 66064 0.0 0.0 408105040 1472 s080 s+10:00 pm 00:00 grep index.php
root 61054 0.0 438073488 280?? s 10:00 pm 00:00 php index.php

 php

function echomsg($prefix, $suffix="") {
//process id
$pid = getmypid(); 
//process group id
$pgid = posix_getpgid($pid);
//session id
$sid = posix_getsid($pid); 
//parent process id
$ppid = posix_getppid();

echo "[{$prefix}] process id: {$pid}, parent process id: {$ppid}, process group id: {$pgid}, session id: {$sd} {$suffix}". php_eol;
}

//[parent] process id: 61052, parent process id: 8243, process group id: 61052, session id: 8243
echomsg("parent");

//the first fork process
$pid = pcntl_fork();
if ( $pid  0 ) {
//[parent1] process id: 61052, parent process id: 8243, process group id: 61052, session id: 8243 exited the process
echoes ("parent1", "exited the process");
exit;
}

//the child process id created is 61053, but the process group, session, and parent process are still the same
//[child1] process id: 61053, parent process id: 61052, process group id: 61052, session id: 8243
echomsg("child1");

//calling the posix_setsid function will create a new session and process group, and set the process group id and session id to that process id
if (-1 === \posix_setsid()) {
throw new exception("setsid fail");
}

//now you will find that both the process group id and session id have changed to 61053, which is equivalent to starting a session window similar to a linux terminal
//[child1] process id: 61053, parent process id: 61052, process group id: 61053, session id: 61053
echomsg("child1");

//second fork process
//the reason for requiring a secondary fork process here is to avoid being associated with terminal controlled processes. this process 61052 was created in terminal mode
//need to detach from process 61052 to ensure the stability of the daemon process
$pid = pcntl_fork();
if ( $pid   0 ) {
//[parent2] process id: 61053, parent process id: 61052, process group id: 61053, session id: 61053 exited the process
echoes ("parent2", "exited the process");
exit;
}

//at this point, the process has broken free from the control of the terminal process and formed a daemon process
//[child2] process id: 61054, parent process id: 61053, process group id: 61053, session id: 61053. this process is retained
echoes ("child2", "this process is reserved");

sleep(100);

// workerman/Worker.php:554
/**
* Run all worker instances.
*Run process
* @return void
*/
public static function runAll()
{
static::checkSapiEnv();
static::init();
static::parseCommand();
static::lock();
//Create a process and form a daemon process
static::daemonize();
static::initWorkers();
static::installSignal();
static::saveMasterPid();
static::lock(\LOCK_UN);
static::displayUI();
static::forkWorkers();
static::resetStd();
static::monitorWorkers();
}

// workerman/Worker.php:1262
/**
* Run as daemon mode.
*Run in daemon mode
* @throws Exception
*/
protected static function daemonize()
{
//Determine whether it is already in a guarded state and whether the current system is in a Linux environment
if (! static::$daemonize || static::$_OS !== \OS_TYPE_LINUX) {
return;
}

//If umask is set to 0, the file permissions created by the current process will be 777, which has the highest permission
\umask(0);

//The first time creating a process
$pid = \pcntl_fork();
if (-1 === $pid) {
//Process creation failed
throw new Exception('Fork fail');
} elseif ($pid > 0) {
//Main process exits
exit(0);
}

//The child process continues to execute
//By calling the posix_setsid function, a process can detach from its parent process and transform into a daemon process
if (-1 === \posix_setsid()) {
throw new Exception("Setsid fail");
}

//The second creation process, in a System V based system, exits by forking the parent process again
//Ensure that the formed daemon process does not become the first session process and does not have control terminals
$pid = \pcntl_fork();
if (-1 === $pid) {
//Process creation failed
throw new Exception("Fork fail");
} elseif (0 !== $pid) {
//Main process exits
exit(0);
}

//The child process continues to execute
}