On Sun, 28 Feb 2021 03:50:13 GMT, liach <github.com+7806504+li...@openjdk.org>
wrote:
>> src/java.desktop/share/classes/sun/font/SunFontManager.java line 1452:
>>
>>> 1450: if (platformFontMap == null) {
>>> 1451: platformFontMap = populateHardcodedFileNameMap();
>>> 1452: SunFontManager.platformFontMap = platformFontMap;
>>
>> I am not sure it is enough for "thread-safe initialization". The
>> "platformFontMap" might not be null, but its content can be
>> broken/incomplete at this point.
>
> https://github.com/openjdk/jdk/pull/2691#issuecomment-784367127
>
> In short, previously platformFontMap references were field set/gets and may
> be inconsistent due to concurrency. It is now moved to a local variable; also
> the map modifications have been moved to fields to avoid concurrency issues
> with hash map as far as I can see.
One thread may create the local platformFontMap, then set the static
SunFontManager.platformFontMap field, and then initialize the platformFontMap
or mix these operations. The second thread may see non-null
SunFontManager.platformFontMap which is not still initialized.
-------------
PR: https://git.openjdk.java.net/jdk/pull/2762
