Current SPDK thread library has a issue which occurs if there is
a race between exiting thread and unregistering io_device.
For example, there are two threads. Thread 1 registers a device
and thread 2 gets a channel of the device. Then if thread 1 starts
exiting and unregisters the device, and then thread 2 puts the channel,
thread 2 sends a message to thread 1 to complete releasing the device,
thread 1 already moved exited. Hence thread 2 failed to send the
message.
This patch fixes the race issue. The code is verified by adding
a unit test case.
In detail, add a count, unregistering_dev, to struct spdk_thread,
increment it if a callback is specified to spdk_io_device_unregister(),
and then decrement it in _finish_unregister(), and thread_exit()
checks if it is zero.
The contents of struct spdk_thread is changed but it is not public
data structure, and hence suppress it for ABI testing.
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Idf5faa55335c3ea89f47ccce32687a6be2e26c68
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5796
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: <dongx.yi@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
6fdc71ec18