Summary

Deprecate the UseLinuxPosixThreadCPUClocks flag and remove it in a future release

Problem

The UseLinuxPosixThreadCPUClocks flag was added in Java 6 to allow users to select a new, fast, Thread CPU time API on Linux, if it was available. In 6u23 and 7 it was enabled by default. There is no reason for anyone to opt out of using this API today (nor for quite a long time).

Solution

Deprecate the UseLinuxPosixThreadCPUClocks flag in JDK 24, make it obsolete in JDK 25 and expire it in JDK 26.

Specification

Update the flag description to show it is deprecated:

    product(bool, UseLinuxPosixThreadCPUClocks, true,                     \
-          "enable fast Linux Posix clocks where available")             \
+          "(Deprecated) enable fast Linux Posix clocks where available") \

Add the flag to the deprecated flag table to deprecate in 24, obsolete in 25 and remove in 26:

+#ifdef LINUX
+  { "UseLinuxPosixThreadCPUClocks", JDK_Version::jdk(24), JDK_Version::jdk(25), JDK_Version::jdk(26) },
+#endif