diff options
Diffstat (limited to 'sys/kern/kern_thread.c')
| -rw-r--r-- | sys/kern/kern_thread.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c index 7370fd919203..48aac8e057b8 100644 --- a/sys/kern/kern_thread.c +++ b/sys/kern/kern_thread.c @@ -710,6 +710,35 @@ thread_reap_callout_cb(void *arg __unused) } /* + * Calling this function guarantees that any thread that exited before + * the call is reaped when the function returns. By 'exited' we mean + * a thread removed from the process linkage with thread_unlink(). + * Practically this means that caller must lock/unlock corresponding + * process lock before the call, to synchronize with thread_exit(). + */ +void +thread_reap_barrier(void) +{ + struct task *t; + + /* + * First do context switches to each CPU to ensure that all + * PCPU pc_deadthreads are moved to zombie list. + */ + quiesce_all_cpus("", PDROP); + + /* + * Second, fire the task in the same thread as normal + * thread_reap() is done, to serialize reaping. + */ + t = malloc(sizeof(*t), M_TEMP, M_WAITOK); + TASK_INIT(t, 0, thread_reap_task_cb, t); + taskqueue_enqueue(taskqueue_thread, t); + taskqueue_drain(taskqueue_thread, t); + free(t, M_TEMP); +} + +/* * Allocate a thread. */ struct thread * |