Volume, Output: use new class PeriodClock instead of GTimer

Makefile.am

@@ -299,6 +299,7 @@ libsystem_a_SOURCES = \
 	src/system/EventFD.cxx src/system/EventFD.hxx \
 	src/system/SignalFD.cxx src/system/SignalFD.hxx \
 	src/system/EPollFD.cxx src/system/EPollFD.hxx \
+	src/system/PeriodClock.hxx \
 	src/system/Clock.cxx src/system/Clock.hxx
 
 # Event loop library

src/Main.cxx

@@ -544,7 +544,6 @@ int mpd_main(int argc, char *argv[])
 	playlist_list_global_finish();
 	input_stream_global_finish();
 	audio_output_all_finish();
-	volume_finish();
 	mapper_finish();
 	delete instance->partition;
 	command_finish();

src/OutputAll.cxx

@@ -225,10 +225,7 @@ audio_output_reset_reopen(struct audio_output *ao)
 {
 	const ScopeLock protect(ao->mutex);
 
-	if (!ao->open && ao->fail_timer != nullptr) {
-		g_timer_destroy(ao->fail_timer);
-		ao->fail_timer = nullptr;
-	}
+	ao->fail_timer.Reset();
 }
 
 /**

src/OutputControl.cxx

@@ -32,8 +32,6 @@
 #include "util/Error.hxx"
 #include "Log.hxx"
 
-#include <glib.h>
-
 #include <assert.h>
 #include <stdlib.h>
 
@@ -152,10 +150,7 @@ audio_output_open(struct audio_output *ao,
 	assert(ao->allow_play);
 	assert(audio_format.IsValid());
 
-	if (ao->fail_timer != nullptr) {
-		g_timer_destroy(ao->fail_timer);
-		ao->fail_timer = nullptr;
-	}
+	ao->fail_timer.Reset();
 
 	if (ao->open && audio_format == ao->in_audio_format) {
 		assert(ao->pipe == &mp ||
@@ -213,14 +208,12 @@ audio_output_close_locked(struct audio_output *ao)
 	if (ao->mixer != nullptr)
 		mixer_auto_close(ao->mixer);
 
-	assert(!ao->open || ao->fail_timer == nullptr);
+	assert(!ao->open || !ao->fail_timer.IsDefined());
 
 	if (ao->open)
 		ao_command(ao, AO_COMMAND_CLOSE);
-	else if (ao->fail_timer != nullptr) {
-		g_timer_destroy(ao->fail_timer);
-		ao->fail_timer = nullptr;
-	}
+	else
+		ao->fail_timer.Reset();
 }
 
 bool
@@ -231,8 +224,7 @@ audio_output_update(struct audio_output *ao,
 	const ScopeLock protect(ao->mutex);
 
 	if (ao->enabled && ao->really_enabled) {
-		if (ao->fail_timer == nullptr ||
-		    g_timer_elapsed(ao->fail_timer, nullptr) > REOPEN_AFTER) {
+		if (ao->fail_timer.Check(REOPEN_AFTER * 1000)) {
 			return audio_output_open(ao, audio_format, mp);
 		}
 	} else if (audio_output_is_open(ao))
@@ -312,7 +304,7 @@ audio_output_release(struct audio_output *ao)
 void audio_output_close(struct audio_output *ao)
 {
 	assert(ao != nullptr);
-	assert(!ao->open || ao->fail_timer == nullptr);
+	assert(!ao->open || !ao->fail_timer.IsDefined());
 
 	const ScopeLock protect(ao->mutex);
 	audio_output_close_locked(ao);
@@ -322,7 +314,7 @@ void audio_output_finish(struct audio_output *ao)
 {
 	audio_output_close(ao);
 
-	assert(ao->fail_timer == nullptr);
+	assert(!ao->fail_timer.IsDefined());
 
 	if (ao->thread.IsDefined()) {
 		assert(ao->allow_play);

src/OutputFinish.cxx

@@ -29,7 +29,7 @@ void
 ao_base_finish(struct audio_output *ao)
 {
 	assert(!ao->open);
-	assert(ao->fail_timer == nullptr);
+	assert(!ao->fail_timer.IsDefined());
 	assert(!ao->thread.IsDefined());
 
 	if (ao->mixer != nullptr)
@@ -44,7 +44,7 @@ void
 audio_output_free(struct audio_output *ao)
 {
 	assert(!ao->open);
-	assert(ao->fail_timer == nullptr);
+	assert(!ao->fail_timer.IsDefined());
 	assert(!ao->thread.IsDefined());
 
 	ao_plugin_finish(ao);

src/OutputInit.cxx

@@ -173,7 +173,6 @@ ao_base_init(struct audio_output *ao,
 	ao->allow_play = true;
 	ao->in_playback_loop = false;
 	ao->woken_for_play = false;
-	ao->fail_timer = nullptr;
 
 	/* set up the filter chain */
 

src/OutputInternal.hxx

@@ -25,15 +25,13 @@
 #include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
 #include "thread/Thread.hxx"
-
-#include <time.h>
+#include "system/PeriodClock.hxx"
 
 class Error;
 class Filter;
 class MusicPipe;
 struct config_param;
 struct PlayerControl;
-typedef struct _GTimer GTimer;
 
 enum audio_output_command {
 	AO_COMMAND_NONE = 0,
@@ -147,7 +145,7 @@ struct audio_output {
 	 * to estimate how long it should stay disabled (unless
 	 * explicitly reopened with "play").
 	 */
-	GTimer *fail_timer;
+	PeriodClock fail_timer;
 
 	/**
 	 * The configured audio format.

src/OutputThread.cxx

@@ -35,8 +35,6 @@
 #include "Log.hxx"
 #include "Compiler.h"
 
-#include <glib.h>
-
 #include <assert.h>
 #include <string.h>
 
@@ -137,14 +135,7 @@ ao_open(struct audio_output *ao)
 	assert(ao->chunk == nullptr);
 	assert(ao->in_audio_format.IsValid());
 
-	if (ao->fail_timer != nullptr) {
-		/* this can only happen when this
-		   output thread fails while
-		   audio_output_open() is run in the
-		   player thread */
-		g_timer_destroy(ao->fail_timer);
-		ao->fail_timer = nullptr;
-	}
+	ao->fail_timer.Reset();
 
 	/* enable the device (just in case the last enable has failed) */
 
@@ -160,7 +151,7 @@ ao_open(struct audio_output *ao)
 		FormatError(error, "Failed to open filter for \"%s\" [%s]",
 			    ao->name, ao->plugin->name);
 
-		ao->fail_timer = g_timer_new();
+		ao->fail_timer.Update();
 		return;
 	}
 
@@ -180,7 +171,7 @@ ao_open(struct audio_output *ao)
 			    ao->name, ao->plugin->name);
 
 		ao_filter_close(ao);
-		ao->fail_timer = g_timer_new();
+		ao->fail_timer.Update();
 		return;
 	}
 
@@ -190,7 +181,7 @@ ao_open(struct audio_output *ao)
 			    ao->name, ao->plugin->name);
 
 		ao_filter_close(ao);
-		ao->fail_timer = g_timer_new();
+		ao->fail_timer.Update();
 		return;
 	}
 
@@ -256,7 +247,7 @@ ao_reopen_filter(struct audio_output *ao)
 
 		ao->chunk = nullptr;
 		ao->open = false;
-		ao->fail_timer = g_timer_new();
+		ao->fail_timer.Update();
 
 		ao->mutex.unlock();
 		ao_plugin_close(ao);
@@ -445,7 +436,7 @@ ao_play_chunk(struct audio_output *ao, const struct music_chunk *chunk)
 
 		/* don't automatically reopen this device for 10
 		   seconds */
-		ao->fail_timer = g_timer_new();
+		ao->fail_timer.Update();
 		return false;
 	}
 
@@ -469,8 +460,8 @@ ao_play_chunk(struct audio_output *ao, const struct music_chunk *chunk)
 
 			/* don't automatically reopen this device for
 			   10 seconds */
-			assert(ao->fail_timer == nullptr);
-			ao->fail_timer = g_timer_new();
+			assert(!ao->fail_timer.IsDefined());
+			ao->fail_timer.Update();
 
 			return false;
 		}

src/Volume.cxx

@@ -23,6 +23,7 @@
 #include "Idle.hxx"
 #include "GlobalEvents.hxx"
 #include "util/Domain.hxx"
+#include "system/PeriodClock.hxx"
 #include "Log.hxx"
 
 #include <glib.h>
@@ -39,7 +40,7 @@ static unsigned volume_software_set = 100;
 /** the cached hardware mixer value; invalid if negative */
 static int last_hardware_volume = -1;
 /** the age of #last_hardware_volume */
-static GTimer *hardware_volume_timer;
+static PeriodClock hardware_volume_clock;
 
 /**
  * Handler for #GlobalEvents::MIXER.
@@ -54,29 +55,19 @@ mixer_event_callback(void)
 	idle_add(IDLE_MIXER);
 }
 
-void volume_finish(void)
-{
-	g_timer_destroy(hardware_volume_timer);
-}
-
 void volume_init(void)
 {
-	hardware_volume_timer = g_timer_new();
-
 	GlobalEvents::Register(GlobalEvents::MIXER, mixer_event_callback);
 }
 
 int volume_level_get(void)
 {
-	assert(hardware_volume_timer != nullptr);
-
 	if (last_hardware_volume >= 0 &&
-	    g_timer_elapsed(hardware_volume_timer, nullptr) < 1.0)
+	    !hardware_volume_clock.CheckUpdate(1000))
 		/* throttle access to hardware mixers */
 		return last_hardware_volume;
 
 	last_hardware_volume = mixer_all_get_volume();
-	g_timer_start(hardware_volume_timer);
 	return last_hardware_volume;
 }
 

src/Volume.hxx

@@ -26,8 +26,6 @@
 
 void volume_init(void);
 
-void volume_finish(void);
-
 gcc_pure
 int volume_level_get(void);
 

src/system/PeriodClock.hxx

@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2003-2013 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_PERIOD_CLOCK_HXX
+#define MPD_PERIOD_CLOCK_HXX
+
+#include "Clock.hxx"
+
+/**
+ * This is a stopwatch which saves the timestamp of an event, and can
+ * check whether a specified time span has passed since then.
+ */
+class PeriodClock {
+protected:
+  typedef unsigned Stamp;
+
+private:
+  Stamp last;
+
+public:
+  /**
+   * Initializes the object, setting the last time stamp to "0",
+   * i.e. a Check() will always succeed.  If you do not want this
+   * default behaviour, call Update() immediately after creating the
+   * object.
+   */
+  constexpr
+  PeriodClock():last(0) {}
+
+protected:
+  static Stamp GetNow() {
+    return MonotonicClockMS();
+  }
+
+  constexpr int Elapsed(Stamp now) const {
+    return last == 0
+      ? -1
+      : now - last;
+  }
+
+  constexpr bool Check(Stamp now, unsigned duration) const {
+    return now >= last + duration;
+  }
+
+  void Update(Stamp now) {
+    last = now;
+  }
+
+public:
+  bool IsDefined() const {
+    return last != 0;
+  }
+
+  /**
+   * Resets the clock.
+   */
+  void Reset() {
+    last = 0;
+  }
+
+  /**
+   * Returns the number of milliseconds elapsed since the last
+   * update().  Returns -1 if update() was never called.
+   */
+  int Elapsed() const {
+    return Elapsed(GetNow());
+  }
+
+  /**
+   * Combines a call to Elapsed() and Update().
+   */
+  int ElapsedUpdate() {
+    const auto now = GetNow();
+    int result = Elapsed(now);
+    Update(now);
+    return result;
+  }
+
+  /**
+   * Checks whether the specified duration has passed since the last
+   * update.
+   *
+   * @param duration the duration in milliseconds
+   */
+  bool Check(unsigned duration) const {
+    return Check(GetNow(), duration);
+  }
+
+  /**
+   * Updates the time stamp, setting it to the current clock.
+   */
+  void Update() {
+    Update(GetNow());
+  }
+
+  /**
+   * Updates the time stamp, setting it to the current clock plus the
+   * specified offset.
+   */
+  void UpdateWithOffset(int offset) {
+    Update(GetNow() + offset);
+  }
+
+  /**
+   * Checks whether the specified duration has passed since the last
+   * update.  If yes, it updates the time stamp.
+   *
+   * @param duration the duration in milliseconds
+   */
+  bool CheckUpdate(unsigned duration) {
+    Stamp now = GetNow();
+    if (Check(now, duration)) {
+      Update(now);
+      return true;
+    } else
+      return false;
+  }
+
+  /**
+   * Checks whether the specified duration has passed since the last
+   * update.  After that, it updates the time stamp.
+   *
+   * @param duration the duration in milliseconds
+   */
+  bool CheckAlwaysUpdate(unsigned duration) {
+    Stamp now = GetNow();
+    bool ret = Check(now, duration);
+    Update(now);
+    return ret;
+  }
+};
+
+#endif