[PATCH] Review request: 6962637 TEST_BUG: java/io/File/MaxPathLength.java may fail in busy system

[David Holmes]

On 22/08/2012 6:10 PM, Eric Wang wrote:
> Hi David,
>
> To use dirFile.length() == 0 to replace the disk space measurement as
> guess the original test tries to prove that there's no extra disk spent
> when creating empty folders.

Sorry I don't understand. File.length() says:

public long length()

Returns the length of the file denoted by this abstract pathname. The 
return value is unspecified if this pathname denotes a directory.

Where it is required to distinguish an I/O exception from the case that 
0L is returned, or where several attributes of the same file are 
required at the same time, then the Files.readAttributes method may be used.

Returns:
     The length, in bytes, of the file denoted by this abstract 
pathname, or 0L if the file does not exist. Some operating systems may 
return 0L for pathnames denoting system-dependent entities such as 
devices or pipes.

----

In this case we verify we have a directory before we do the length() 
test, which means the return value from length is unspecified.

So I don't understand how length() is being used here.

David
-----


> Regards,
> Eric
>
> On 2012/8/22 16:02, David Holmes wrote:
>> Hi Eric,
>>
>> On 22/08/2012 5:54 PM, Eric Wang wrote:
>>> Please help to review the fix below for bug **6962637
>>> <http://monaco.us.oracle.com/detail.jsf?cr=6962637> TEST_BUG:
>>> java/io/File/MaxPathLength.java may fail in busy system
>>> http://dl.dropbox.com/u/90659131/fixes/6962637/webrev/index.html
>>>
>>> Root cause is the test is not reliable when system is busy, if disk
>>> space is changed by some other program, test can fail. so the fix is to
>>> check file.length() instead of disk space.
>>
>> I can not figure out what the original version of the test was doing
>> with the disk space measurements but I can certainly appreciate that
>> they could be changing dynamically while the test is running.
>>
>> But I don't really understand why dirFile is expected to have a zero
>> length ???
>>
>> David
>>
>>> Regards,
>>> Eric
>