Hi,
Please review this change to disable the file canonicalization cache by
default.
Bug:
https://bugs.openjdk.java.net/browse/JDK-8207005
From the bug report:
"The file canonicalization cache was added back in JDK 1.4.2 in order to
improve startup time.
The cache has long-standing correctness issues (JDK-7066948, for
example). For this reason, it has been desired to disable the cache by
default, but the increase to startup time was undesirable.
Recent JDK releases have removed usages of the cache, in particular from
FilePermission (JDK-8164705 in JDK 9). This reduced usage of the
canonicalization cache should also reduce the startup effect of
disabling the cache by default. Measurements support this. Previous
measurements showed the startup effect of disabling the cache on Linux
to be 3-6%, depending on the specific benchmark. The same comparison
performed last month now shows no startup change on Linux.
The file canonicalization cache can still be enabled by setting the
"sun.io.useCanonCaches" system property. This is merely a change to the
default value."
Here is the diff:
--- a/src/java.base/share/classes/java/io/FileSystem.java
@@ -231,8 +231,8 @@
// Flags for enabling/disabling performance optimizations for file
// name canonicalization
- static boolean useCanonCaches = true;
- static boolean useCanonPrefixCache = true;
+ static boolean useCanonCaches = false;
+ static boolean useCanonPrefixCache = false;
private static boolean getBooleanProperty(String prop, boolean
defaultVal) {
--
Thanks,
-Brent
