Daemon: move code to class PidFile

Makefile.am

@@ -159,6 +159,7 @@ src_mpd_SOURCES = \
 	src/Win32Main.cxx \
 	src/GlobalEvents.cxx src/GlobalEvents.hxx \
 	src/Daemon.cxx src/Daemon.hxx \
+	src/PidFile.hxx \
 	src/AudioCompress/compress.c \
 	src/MixRampInfo.hxx \
 	src/MusicBuffer.cxx src/MusicBuffer.hxx \

src/Daemon.cxx

@@ -23,9 +23,9 @@
 #include "fs/AllocatedPath.hxx"
 #include "fs/FileSystem.hxx"
 #include "util/Domain.hxx"
+#include "PidFile.hxx"
 #include "Log.hxx"
 
-#include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -164,28 +164,14 @@ daemonize_detach(void)
 void
 daemonize(bool detach)
 {
-	FILE *fp = nullptr;
-
-	if (!pidfile.IsNull()) {
-		/* do this before daemon'izing so we can fail gracefully if we can't
-		 * write to the pid file */
-		LogDebug(daemon_domain, "opening pid file");
-		fp = FOpen(pidfile, "w+");
-		if (!fp) {
-			const std::string utf8 = pidfile.ToUTF8();
-			FormatFatalSystemError("Failed to create pid file \"%s\"",
-					       pidfile.c_str());
-		}
-	}
+	/* do this before daemon'izing so we can fail gracefully if we
+	   can't write to the pid file */
+	PidFile pidfile2(pidfile);
 
 	if (detach)
 		daemonize_detach();
 
-	if (!pidfile.IsNull()) {
-		LogDebug(daemon_domain, "writing pid file");
-		fprintf(fp, "%lu\n", (unsigned long)getpid());
-		fclose(fp);
-	}
+	pidfile2.Write();
 }
 
 void

src/PidFile.hxx

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_PID_FILE_HXX
+#define MPD_PID_FILE_HXX
+
+#include "fs/FileSystem.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "Log.hxx"
+
+#include <assert.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+class PidFile {
+	FILE *file;
+
+public:
+	PidFile(const AllocatedPath &path):file(nullptr) {
+		if (path.IsNull())
+			return;
+
+		file = FOpen(path, "w+");
+		if (file == nullptr) {
+			const std::string utf8 = path.ToUTF8();
+			FormatFatalSystemError("Failed to create pid file \"%s\"",
+					       path.c_str());
+		}
+	}
+
+	PidFile(const PidFile &) = delete;
+
+	void Write(pid_t pid) {
+		if (file == nullptr)
+			return;
+
+		fprintf(file, "%lu\n", (unsigned long)pid);
+		fclose(file);
+	}
+
+	void Write() {
+		if (file == nullptr)
+			return;
+
+		Write(getpid());
+	}
+};
+
+#endif