Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
For specifics regarding the bug see GLIBC BUGID 261237 :
   http://www.mail-archive.com/###@###.###/msg10837.html.

Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
is used. (The simple C test-case provided in the GLIBC bug report manifests the
hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
and monitorenter. All those operations may result in calls to pthread_cond_timedwait().

Workarounds:
- Upgrade to a version of linux/nptl that does not have the bug
- Use LD_ASSUME_KERNEL to select the older non-ntpl libpthread.so