Changeset 207338 in webkit

Timestamp:

Oct 14, 2016 7:56:05 AM (8 years ago)

Author:

Chris Dumez

Message:

[Mac] Allow throttling of background tabs that have media elements with no audible audio
​https://bugs.webkit.org/show_bug.cgi?id=163402
<rdar://problem/28056151>

Reviewed by Gavin Barraclough.

Allow throttling of background tabs that have media elements with no audible audio.
We were taking an media assertion from the PageThrottler as soon as there was a
media element playing on the page. This prevented throttling of background tabs
even if those media elements had no audible audio, which was unfortunate.

We now have more fine-grained rules for when HTMLMediaElement should take an
assertion. I also added release logging to help debug such issues in the
future.

• html/HTMLMediaElement.cpp:

(WebCore::HTMLMediaElement::setMuted):
(WebCore::HTMLMediaElement::updateVolume):
(WebCore::HTMLMediaElement::updatePlayState):
(WebCore::HTMLMediaElement::updateAudioAssertionState):
(WebCore::HTMLMediaElement::effectiveMuted): Deleted.

• html/HTMLMediaElement.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• html/HTMLMediaElement.cpp (modified) (7 diffs)
• html/HTMLMediaElement.h (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2016-10-14  Chris Dumez  <cdumez@apple.com>
+
+        [Mac] Allow throttling of background tabs that have media elements with no audible audio
+        https://bugs.webkit.org/show_bug.cgi?id=163402
+        <rdar://problem/28056151>
+
+        Reviewed by Gavin Barraclough.
+
+        Allow throttling of background tabs that have media elements with no audible audio.
+        We were taking an media assertion from the PageThrottler as soon as there was a
+        media element playing on the page. This prevented throttling of background tabs
+        even if those media elements had no audible audio, which was unfortunate.
+
+        We now have more fine-grained rules for when HTMLMediaElement should take an
+        assertion. I also added release logging to help debug such issues in the
+        future.
+
+        * html/HTMLMediaElement.cpp:
+        (WebCore::HTMLMediaElement::setMuted):
+        (WebCore::HTMLMediaElement::updateVolume):
+        (WebCore::HTMLMediaElement::updatePlayState):
+        (WebCore::HTMLMediaElement::updateAudioAssertionState):
+        (WebCore::HTMLMediaElement::effectiveMuted): Deleted.
+        * html/HTMLMediaElement.h:
+
 2016-10-14  Romain Bellessort  <romain.bellessort@crf.canon.fr>
 

trunk/Source/WebCore/html/HTMLMediaElement.cpp

@@ -3334 +3334 @@
 
     scheduleUpdatePlaybackControlsManager();
+    updateAudioAssertionState();
 }
 
@@ -4853 +4854 @@
         mediaControls()->changedVolume();
 #endif
+
+    updateAudioAssertionState();
 }
 
@@ -4872 +4875 @@
         if (hasMediaControls())
             mediaControls()->playbackStopped();
-        m_activityToken = nullptr;
+        updateAudioAssertionState();
         return;
     }
@@ -4910 +4913 @@
         if (hasMediaControls())
             mediaControls()->playbackStarted();
-        if (document().page())
-            m_activityToken = document().page()->pageThrottler().mediaActivityToken();
 
         startPlaybackProgressTimer();
@@ -4933 +4934 @@
         if (hasMediaControls())
             mediaControls()->playbackStopped();
-        m_activityToken = nullptr;
     }
     
@@ -4941 +4941 @@
     m_hasEverHadAudio |= hasAudio();
     m_hasEverHadVideo |= hasVideo();
+
+    updateAudioAssertionState();
 }
 
@@ -7001 +7003 @@
 }
 
+void HTMLMediaElement::updateAudioAssertionState()
+{
+    auto* page = document().page();
+    if (!page) {
+        m_audioActivityToken = nullptr;
+        return;
+    }
+
+#define RELEASE_AUDIO_TOKEN(REASON) \
+    RELEASE_LOG_IF(page->isAlwaysOnLoggingAllowed() && m_audioActivityToken, Media, "%p - HTMLMediaElement releases audio activity token, reason: " REASON, this); \
+    m_audioActivityToken = nullptr
+
+    if (!hasAudio()) {
+        RELEASE_AUDIO_TOKEN("No audio");
+        return;
+    }
+    if (!isPlaying()) {
+        RELEASE_AUDIO_TOKEN("Not playing");
+        return;
+    }
+    if (effectiveMuted()) {
+        RELEASE_AUDIO_TOKEN("Audio is muted");
+        return;
+    }
+    if (!volume()) {
+        RELEASE_AUDIO_TOKEN("Volume is 0");
+        return;
+    }
+    if (!m_audioActivityToken) {
+        RELEASE_LOG_IF(page->isAlwaysOnLoggingAllowed(), Media, "%p - HTMLMediaElement takes audio activity token because there is audible audio", this);
+        m_audioActivityToken = page->pageThrottler().mediaActivityToken();
+    }
+
+#undef RELEASE_AUDIO_TOKEN
+}
+
 bool HTMLMediaElement::doesHaveAttribute(const AtomicString& attribute, AtomicString* value) const
 {

trunk/Source/WebCore/html/HTMLMediaElement.h

@@ -770 +770 @@
     bool effectiveMuted() const;
 
+    void updateAudioAssertionState();
+
     void registerWithDocument(Document&);
     void unregisterWithDocument(Document&);
@@ -1006 +1008 @@
 
     std::unique_ptr<MediaElementSession> m_mediaSession;
-    PageActivityAssertionToken m_activityToken;
+    PageActivityAssertionToken m_audioActivityToken;
     size_t m_reportedExtraMemoryCost;