On 19/12/17 5:13 PM, Jaikiran Pai wrote:
Looking at the JDK code, I still am not sure which exact code path
triggers this stale/invalid cache in this specific case, but
apparently it does.
Now that we know the canonical path cache is playing a role, I think the
only way this issue makes sense is the following flow:
1. Some code somewhere invokes getCanonicalPath on the *non-existent*
"link1" file (and other similar symlink files).
2. Given that the file "link1" is non-existent, the JDK implementation
gets back a path which points back to "link1" itself (getCanonicalPath
is allowed on non-existent files) and then caches this result in its cache.
3. A symlink then gets created with link1 pointing to a file1. At this
point "link1" file does exist. The cache however isn't updated.
4. A call to getCanonicalPath on the now existent "link1" file happens.
Given that a previous invocation has cached (an invalid) value, the
invalid value pointing back to "link1" is returned back.
That's a guess. What's interesting is #1 and what/who triggers that call
(maybe explicit or somewhere implicit).
But either way, at this point, I'm happy that we know what's going on
and this ended up being a JVM issue (and a known/acknowledged one).
Thanks Stefan for narrowing this down.
-Jaikiran
[exec] [junit] Testsuite:
org.apache.tools.ant.taskdefs.optional.unix.SymlinkTest
[exec] [junit] Tests run: 6, Failures: 0, Errors: 0, Skipped: 0, Time
elapsed: 0.276 sec
-Jaikiran
On 19/12/17 5:02 PM, [email protected]:
Repository: ant
Updated Branches:
refs/heads/master c2c821a38 -> 3dad11d41
disable a bunch of caches, just so we've tried that as well
Project:http://git-wip-us.apache.org/repos/asf/ant/repo
Commit:http://git-wip-us.apache.org/repos/asf/ant/commit/3dad11d4
Tree:http://git-wip-us.apache.org/repos/asf/ant/tree/3dad11d4
Diff:http://git-wip-us.apache.org/repos/asf/ant/diff/3dad11d4
Branch: refs/heads/master
Commit: 3dad11d4191074a95b0d83397e73a99bd5b3f0c1
Parents: c2c821a
Author: Stefan Bodewig<[email protected]>
Authored: Tue Dec 19 12:31:26 2017 +0100
Committer: Stefan Bodewig<[email protected]>
Committed: Tue Dec 19 12:31:26 2017 +0100
----------------------------------------------------------------------
build.xml | 2 ++
1 file changed, 2 insertions(+)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/ant/blob/3dad11d4/build.xml
----------------------------------------------------------------------
diff --git a/build.xml b/build.xml
index 36df7a4..0939eb5 100644
--- a/build.xml
+++ b/build.xml
@@ -1665,6 +1665,8 @@ ${antunit.reports}
<sysproperty key="tests.and.ant.share.classloader"
value="${tests.and.ant.share.classloader}"/>
<sysproperty key="java.io.tmpdir" file="${build.junit.tmpdir}"/>
+ <sysproperty key="sun.io.useCanonCaches" value="false"/>
+ <sysproperty key="sun.io.useCanonPrefixCache" value="false"/>
<classpath>
<path refid="tests-runtime-classpath"/>
<pathelement location="${junit.collector.dir}"/>
