jeff 2007-06-12 07:24:47 UTC
FreeBSD src repository
Modified files:
sys/sys proc.h
sys/kern kern_thread.c
Log:
Solve a complex exit race introduced with thread_lock:
- Add a count of exiting threads, p_exitthreads, to struct proc.
- Increment p_exithreads when we set the deadthread in thread_exit().
- When we thread_stash() a deadthread use an atomic to drop the count.
- Spin until the p_exithreads count reaches 0 in thread_wait().
- Lock the last exiting thread momentarily to be certain that it has
exited cpu_throw().
- Restructure thread_wait(). It does not need a loop as there will only
ever be one thread.
Tested by: moose@opera.com
Reported by: kris, moose@opera.com
Revision Changes Path
1.249 +33 -15 src/sys/kern/kern_thread.c
1.484 +1 -0 src/sys/sys/proc.h