PHP实现的多进程控制demo示例

declare(ticks=1);function sigHandler($signal){  echo "a child exited/n";}pcntl_signal(SIGCHLD, sigHandler, false);echo "this is " . posix_getpid() . PHP_EOL;for($i=0; $i<3; $i++){  $pid = pcntl_fork();  if($pid == -1)  {    echo 'fork failed ' . PHP_EOL;  }  else if($pid)  {  }  else  {    $pid = posix_getpid();    echo 'child ' . $pid . ' ' . time() . PHP_EOL;    sleep(rand(2,5));    echo 'child ' . $pid . ' done ' . time() . PHP_EOL;    exit(0);  }}do{  $pid = pcntl_wait($status);  echo 'child quit ' . $pid . PHP_EOL;}while($pid > 0);echo 'parent done' . PHP_EOL;