107762 - Fastload leaks spec strings

Status: VERIFIED DUPLICATE of bug 106860

(Core :: XPCOM, defect)

Description

[David :Bienvenu]

Here's a sample stack trace. It's not an accurate one because we're purifying
release builds, but the problem is that a couple hash tables aren't freing the
data allocated in the entries. Patch upcoming.

    malloc         [msvcrt.DLL]
    nsMemoryImpl::Alloc(UINT) [nsMemoryImpl.obj:320]
    nsMemory::Clone(void const*,UINT) [nsMemoryImpl.cpp:592]
    nsFastLoadFileUpdater::Open(nsFastLoadFileReader *) [nsFastLoadFile.cpp:2293]
                // release the reference.
                NS_IF_ADDREF(obj);
                writeEntry->mObject = NS_REINTERPRET_CAST(nsISupports*, key);
     =>         writeEntry->mOID = oid;
                writeEntry->mInfo = *NS_STATIC_CAST(nsFastLoadSharpObjectInfo*,
                                                    readEntry);
            }
    NS_NewFastLoadFileUpdater(nsIObjectOutputStream * *,nsIOutputStream
*,nsIObjectInputStream *) [nsFastLoadFile.cpp:2339]

Comment 1

[David :Bienvenu]

Attachment: proposed fix

Comment 2

[David :Bienvenu]

Fix is to enumerate the hash tables freeing the strings - I'm not sure if the
null check is needed - does nsMemory check for null? I don't see the leaks in
purify after this change. Anyway, requesting reviews.

Comment 3

[Brendan Eich [:brendan]]

No enumeration should be necessary, because the table clears entries when it is
Finished or Destroyed, and Finish calls clearEntry.  See strmap_ClearEntry in
nsFastLoadFile.cpp.

I think this is a dup of bug 106860, which cites the same purify-reported leaks.
 I believe we must be leaking the entire XPCOM object (nsFastLoadFileWriter or
nsFastLoadFileUpdater) to cause these string leaks.  Enumerating to free the
mStrings just papers over this larger leak.

/be

*** This bug has been marked as a duplicate of 106860 ***

Comment 4

[David :Bienvenu]

yes, I think you're right - I just discovered that under Purify - don't know why
it didn't show up the second time I ran Purify. 

Comment 5

[Brendan Eich [:brendan]]

Anyone have XPCOM_MEM_LEAK_LOG output showing an nsFastLoadFile* leak?

/be

Comment 6

[[e-mail] (gone - use [e-mail] instead)]

verified dup.