Extract _spdk_thread_exit() from spdk_thread_exit() and
_spdk_thread_poll() calls _spdk_thread_exit() if the thread is in
the exiting state. spdk_thread_exit() changes to move the state to
the exiting state. The spdk_thread_poll() loop will end after the
thread moves to the exited state because the caller of
spdk_thread_poll() will check if the thread is in the exited state,
and break the loop if true.
If the user does not call spdk_thread_exit() explicitly, the reactor
has to terminate all existing threads at its shutdown. In this case,
multiple threads may have some dependency to release I/O channels or
unregister pollers. So the reactor has the large two loops, the first
loop calls spdk_thread_exit() on all threads, the second loop calls
spdk_thread_destroy() if exited or spdk_thread_poll() otherwise for
each thread until all threads are destroyed.
Besides, change the return value of spdk_thread_exit() to return
always 0. Keep it for ABI compatibility. Change ERRLOG to INFOLOG
for _spdk_thread_exit() because it is called repeatedly now. Remove
the check of I/O reference count from _spdk_thread_exit() because
_free_thread() cannot free I/O channel. Refine the unit test
accordingly.
Fixes issue #1288.
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Iee5fb984a96bfac53110fe991dd994ded31dffa4
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/1423
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>