OpenJDK / jdk / jdk10
changeset 18550:6d0f51c99930
8014233: java.lang.Thread should have @Contended on TLR fields
Summary: add the @Contended over three TLR fields.
Reviewed-by: psandoz, chegar, dholmes, dl
| author | shade |
|---|---|
| date | Tue, 25 Jun 2013 20:06:09 +0100 |
| parents | 66e6e111be22 |
| children | 882a3948c6e6 |
| files | jdk/src/share/classes/java/lang/Thread.java |
| diffstat | 1 files changed, 10 insertions(+), 1 deletions(-) [+] |
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--- a/jdk/src/share/classes/java/lang/Thread.java Tue Jun 25 21:51:11 2013 +0800 +++ b/jdk/src/share/classes/java/lang/Thread.java Tue Jun 25 20:06:09 2013 +0100 @@ -1993,12 +1993,21 @@ // The following three initially uninitialized fields are exclusively - // managed by class java.util.concurrent.ThreadLocalRandom. + // managed by class java.util.concurrent.ThreadLocalRandom. These + // fields are used to build the high-performance PRNGs in the + // concurrent code, and we can not risk accidental false sharing. + // Hence, the fields are isolated with @Contended. + /** The current seed for a ThreadLocalRandom */ + @sun.misc.Contended("tlr") long threadLocalRandomSeed; + /** Probe hash value; nonzero if threadLocalRandomSeed initialized */ + @sun.misc.Contended("tlr") int threadLocalRandomProbe; + /** Secondary seed isolated from public ThreadLocalRandom sequence */ + @sun.misc.Contended("tlr") int threadLocalRandomSecondarySeed; /* Some private helper methods */