Respond to termination signals and delete PID file

lib/CLI.php

@@ -94,10 +94,14 @@ USAGE_TEXT;
                     return 0;
                 case "daemon":
                     if ($args['--fork'] !== null) {
-                        $this->fork($args['--fork']);
+                        $pidfile = $this->resolvePID($args['--fork']);
+                        $this->fork($pidfile);
                     }
                     $this->loadConf();
                     Arsse::$obj->get(Service::class)->watch(true);
+                    if (isset($pidfile)) {
+                        unlink($pidfile);
+                    }
                     return 0;
                 case "feed refresh":
                     return (int) !Arsse::$db->feedUpdate((int) $args['<n>'], true);
@@ -282,6 +286,7 @@ USAGE_TEXT;
             default:
                 fclose($pipe[1]);
                 fread($pipe[0], 100);
+                fclose($pipe[0]);
                 # Call exit() in the original process. The process that invoked the daemon must be able to rely on that this exit() happens after initialization is complete and all external communication channels are established and accessible.
                 exit;
         }
@@ -320,4 +325,23 @@ USAGE_TEXT;
             }
         }
     }
+
+    /** Resolves the PID file path and ensures the file or parent directory is writable */
+    protected function resolvePID(string $pidfile): string {
+        $dir = dirname($pidfile);
+        $file = basename($pidfile);
+        if ($base = @realpath($dir)) {
+            $out = "$base/$file";
+            if (file_exists($out)) {
+                if (!is_writable($out)) {
+                    throw new \Exception("PID file is not writable");
+                }
+            } elseif (!is_writable($base)) {
+                throw new \Exception("Cannot create PID file");
+            }
+        } else {
+            throw new \Exception("Parent directory of PID file does not exist");
+        }
+        return $out;
+    }
 }

lib/Service.php

@@ -16,6 +16,7 @@ class Service {
 
     /** @var Service\Driver */
     protected $drv;
+    protected $loop = false;
 
     public function __construct() {
         $driver = Arsse::$conf->serviceDriver;
@@ -23,6 +24,8 @@ class Service {
     }
 
     public function watch(bool $loop = true): \DateTimeInterface {
+        $this->loop = $loop;
+        $this->signalInit();
         $t = new \DateTime();
         do {
             $this->checkIn();
@@ -37,13 +40,14 @@ class Service {
             static::cleanupPost();
             $t->add(Arsse::$conf->serviceFrequency);
             // @codeCoverageIgnoreStart
-            if ($loop) {
+            if ($this->loop) {
                 do {
-                    @time_sleep_until($t->getTimestamp());
+                    sleep((int) max(0, $t->getTimestamp() - time()));
-                } while ($t->getTimestamp() > time());
+                    pcntl_signal_dispatch();
+                } while ($this->loop && $t->getTimestamp() > time());
             }
             // @codeCoverageIgnoreEnd
-        } while ($loop);
+        } while ($this->loop);
         return $t;
     }
 
@@ -88,4 +92,20 @@ class Service {
         }
         return true;
     }
+
+    protected function signalInit(): void {
+        if (function_exists("pcntl_async_signals") && function_exists("pcntl_signal")) {
+            // receive asynchronous signals if supported
+            pcntl_async_signals(true);
+            foreach ([\SIGABRT, \SIGINT, \SIGTERM] as $sig) {
+                pcntl_signal($sig, [$this, "sigTerm"]);
+            }
+        }
+    }
+
+    protected function sigTerm(int $signo): void {
+        $this->loop = false;
+    }
+
+
 }