<Sound Dev> Comment on bug JDK-8013586

[Dan Rollo]

Yikes, Good point Klaus! Forgot the caller wants to actually use a valid stream for the non-exceptional case. Would have to move the is.close() back into a catch clause. I’ll try to post a better one later. (Any unit tests of this sort of thing exist in the tree now? - if not, I could try a unit test too).

> On Jan 9, 2015, at 12:34 PM, Klaus Jaensch <klausj at phonetik.uni-muenchen.de> wrote:
> 
> Hi Dan,
> 
> Am 09.01.2015 um 05:37 schrieb Dan Rollo:
>> Even better, no need for the “catch/throw” chunk, because the method declares those caught exceptions:
>> 
>> 
>> public AudioInputStream getAudioInputStream(File file)
>>         throws UnsupportedAudioFileException, IOException {
>> 
>>     final FileInputStream fis = new FileInputStream(file);
>>     try {
>>         return getAudioInputStream(new BufferedInputStream(fis));
>>     } finally {
>>         fis.close();
>>     }
>> }
> 
> I think your code will not work. If the call to  getAudioInputStream(InputStream) succeeds the code always closes the stream before it is returned. 
> 
> 
> I suggest this approach:  
> 
> public AudioInputStream getAudioInputStream(File file)
>             throws UnsupportedAudioFileException, IOException {
>         FileInputStream fis=new FileInputStream(file);
>         BufferedInputStream bis=new BufferedInputStream(fis);
>         AudioInputStream ais=null;
>         try{
>             ais=getAudioInputStream(bis);
>         } catch(IOException|UnsupportedAudioFileException e) { 
>             if(bis!=null){
>                 bis.close();
>             }
>             throw e;
>         }
>         return ais;
>     }
> 
> Closes the BufferedInputStream as well as the underlying FileInputStream.
> 
> I think the method:
> public AudioInputStream getAudioInputStream(URL url)
> 
> needs to be changed in the same way.
> 
> 
> Best regards,
> Klaus
> 
> 
>> 
>> 
>>> On Jan 7, 2015, at 11:41 PM, Dan Rollo <danrollo at gmail.com <mailto:danrollo at gmail.com>> wrote:
>>> 
>>> If this approach is taken, I’d like to suggest using a ‘final’ var instead of ‘null init/null check’, for example:
>>> 
>>> public AudioInputStream getAudioInputStream(File file)
>>>         throws UnsupportedAudioFileException, IOException {
>>> 
>>>     final FileInputStream fis = new FileInputStream(file);
>>>     try {
>>>         return getAudioInputStream(new BufferedInputStream(fis));
>>>     } catch(IOException|UnsupportedAudioFileException e) {
>>>         throw e;
>>>     } finally {
>>>         fis.close();
>>>     }
>>> }
>>> 
>>> 
>>>> On Jan 7, 2015, at 10:51 PM, Sergey Bylokhov <Sergey.Bylokhov at oracle.com <mailto:Sergey.Bylokhov at oracle.com>> wrote:
>>>> 
>>>> On 08.01.2015 1:13, Phil Race wrote:
>>>>> Its not clear to me if the bug description is implying an exception was thrown
>>>> UnsupportedAudioFileException is thrown if the URL/File does not point to valid audio file data recognized by the specific reader, so AudioSystem will try to move to the next reader and a leak will occur.
>>>> Actually most of our readers are affected.
>>>>> Still, something like what you suggest seems to be needed. 
>>>> right.
>>>>> 
>>>>> The owner of this bug is out until next week so I'll let him comment further 
>>>>> after his return. 
>>>>> 
>>>>> -phil. 
>>>>> 
>>>>> On 01/07/2015 12:42 PM, Mike Clark wrote: 
>>>>>> Hello all, 
>>>>>> 
>>>>>> I wanted to post this as a comment on https://bugs.openjdk.java.net/browse/JDK-8013586 <https://bugs.openjdk.java.net/browse/JDK-8013586>, but apparently getting comment access to that system is a bit of a hurdle.  Anyway.  What follows is, I believe, a fix for the aforementioned bug: 
>>>>>> 
>>>>>> There is a file handle leak in some of the subclasses of javax.sound.sampled.spi.AudioFileReader, such as com.sun.media.sound.WaveFloatFileReader. 
>>>>>> 
>>>>>> Consider com.sun.media.sound.WaveFloatFileReader's method: 
>>>>>> 
>>>>>> public AudioInputStream getAudioInputStream(File file) 
>>>>>>         throws UnsupportedAudioFileException, IOException { 
>>>>>>     return getAudioInputStream( 
>>>>>>         new BufferedInputStream(new FileInputStream(file))); 
>>>>>> } 
>>>>>> 
>>>>>> See how there is no attempt to close the FileInputStream if an exception is thrown?  A file handle will remain open on the file until garbage collection is run. Since garbage collection may never run, the file handle may remain open until the JVM exits. And on Windows the open file handle prevents the file from being deleted, which is problematic. 
>>>>>> 
>>>>>> Could we fix it by adding a try/catch block? 
>>>>>> 
>>>>>> public AudioInputStream getAudioInputStream(File file) 
>>>>>>         throws UnsupportedAudioFileException, IOException { 
>>>>>>     FileInputStream fis = null; 
>>>>>>     try { 
>>>>>>         fis = new FileInputStream(file); 
>>>>>>         return getAudioInputStream(new BufferedInputStream(fis)); 
>>>>>>     } catch(IOException|UnsupportedAudioFileException e) { 
>>>>>>         if (fis != null) { 
>>>>>>             fis.close(); 
>>>>>>         } 
>>>>>>         throw e; 
>>>>>>     } 
>>>>>> } 
>>>>>> 
>>>>>> These AudioFileReader subclass methods are usually called by javax.sound.sampled.AudioSystem.getAudioInputStream(File), which calls getAudioInputStream(File) on all registered subclasses of AudioFileReader.  As such, all subclasses of AudioFileReader in the JRE should be reviewed for this problem. 
>>>>>> 
>>>>>> best regards, 
>>>>>> -Mike 
>>>>>> 
>>>>> 
>>>> 
>>>> 
>>>> -- 
>>>> Best regards, Sergey. 
>>> 
>> 
> 
> 
> -- 
> ------------------------------------------
> Klaus Jaensch
> Muenchen
> Germany
> 
> Institut fuer Phonetik und Sprachverarbeitung
> Schellingstr.3/II
> Room 223 VG
> 80799 München
> 
> Phone (Work): +49-(0)89-2180-2806
> Fax:          +49-(0)89-2180-5790
> EMail: klausj at phonetik.uni-muenchen.de <mailto:klausj at phonetik.uni-muenchen.de>

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