This is a preparation to support voluntary thread termination by
calling spdk_thread_exit().
One of the subsequent patches will allow thread to exit only if
all of its pollers are being unregistered. After the thread is
marked as exited, only unregistering pollers will remain if the
exited thread does not accept registering new poller.
Hence in this patch, we change spdk_poller_register() to fail if the
current thread is marked as exited first.
Then, in subsequent patches, if we remove break from poller
processing in spdk_thread_poll(), poller unregistration of the exited
thread will complete, and we will be able to support voluntary thread
termination easily by checking only the thread is exited and idle.
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: I5b843a07049ef01a5ff402eb521e294182ce2ae2
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/822
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
1e98e82051