fix: avoid `pcntl_wait` blocking

main.php

@@ -25,8 +25,11 @@ $vlmcsd = array(
 );
 
 logging::info('Loading kms-server (' . $version . ')');
+
 declare(ticks = 1);
-pcntl_signal(SIGCHLD, 'subExit'); // receive SIGCHLD signal
+pcntl_signal(SIGCHLD, function() { // receive SIGCHLD signal
+    pcntl_wait($status, WNOHANG); // avoid zombie process
+});
 
 new Process($nginx['command']);
 logging::info('Start nginx server...OK');

src/Daemon.php

@@ -3,10 +3,6 @@
 require_once 'Logger.php';
 require_once 'Process.php';
 
-function subExit(): void {
-    pcntl_wait($status); // avoid zombie process
-}
-
 function msSleep(int $ms): void { // sleep for xxx ms
     for ($i = 0; $i < $ms; $i++) {
         usleep(1000); // split multiple times (avoid SIGCHLD signal)

src/Logger.php

@@ -1,6 +1,6 @@
 <?php
 
-logging::$logLevel = logging::INFO;
+logging::$logLevel = logging::DEBUG;
 
 $logColor = array(
     logging::DEBUG    => '37m', // white