631953 - Linked video makes Firefox enter a busy loop

Status: VERIFIED FIXED

(Core :: Audio/Video, defect)

Description

[Rui Matos]

User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:2.0b10) Gecko/20100101 Firefox/4.0b10
Build Identifier: Mozilla/5.0 (X11; Linux x86_64; rv:2.0b10) Gecko/20100101 Firefox/4.0b10

Visiting the video in the URL makes Firefox enter a 100% CPU using loop. The only way out is killing the process.

Reproducible: Always

Comment 1

[Matthias Versen [:Matti]]

I can confirm a hang with Mozilla/5.0 (Windows NT 6.1; rv:2.0b12pre) Gecko/20110205 Firefox/4.0b12pre SeaMonkey/2.1b3pre

Comment 2

[Matthew Gregan [:kinetik]]

Hangs a current nightly on Linux x86_64 for me, but doesn't hang with my current development debug build.

Comment 3

[Chris Pearce [:cpearce (Not reading bugmail)]]

One problem here is that nsOggReader::mVorbisSerial is initialized to 0, but that's the actual value of the Theora stream's serial (there's no Vorbis stream in that video). So the Ogg @buffered implementation is trying to use Theora pages to calculate Vorbis timestamps. That might be the problem; it's at least causing assertions to fire (for me).

We perhaps need to add flags to nsOggReader to denote whether we have Vorbis and Theora streams. There may be other problems here...

Comment 4

[Matthew Gregan [:kinetik]]

It doesn't hang for me with a local optimized build either (gcc 4.4.5 vs gcc 4.3.3 for the nightlies).  I grabbed the symbols for my current nightly and got a plausible looking stack... it looks like the hang is the problem cpearce already discovered:

#0 ogg_page_checksum_set (og=0x7fff05e2e7a0) at media/libogg/src/ogg_framing.c:294
#1 ogg_sync_pageseek (oy=0x7fff05e2e900, og=0x7fff05e2e8e0) at media/libogg/src/ogg_framing.c:691
#2 PageSync(nsMediaStream *, struct {...} *, PRBool, PRInt64, PRInt64, struct {...} *, int &) (aStream=0x7f74db4be000, aState=0x7fff05e2e900, aCachedDataOnly=1, aOffset=1513812796, 
  age=0x7fff05e2e8e0, aSkippedBytes=@0x7fff05e2e92c) at content/media/ogg/nsOggReader.cpp:1287
#3 nsOggReader::GetBuffered (this=0x7f74d8f75800, aBuffered=0x7f74f0357b20, aStartTime=0) at content/media/ogg/nsOggReader.cpp:1601
#4 nsHTMLMediaElement::GetBuffered (this=0x7f74ddc91ee0, aBuffered=0x7fff05e2ebd0) at content/html/content/src/nsHTMLMediaElement.cpp:2565

Comment 5

[Matthew Gregan [:kinetik]]

Attachment: patch v0

I can reproduce this with a optimized build built with gcc 4.3.3.  This patch fixes the hang.

Comment 6

[Chris Pearce [:cpearce (Not reading bugmail)]]

http://hg.mozilla.org/mozilla-central/rev/dcc45003a979

Comment 7

[u279076]

Cannot reproduce with Firefox 4.0b12pre 20110218.