Every time the telemetry server successfully returns from the accept, it
atomically increases the value of num_clients（if < MAX_CONNECTIONS） and then
executes pthread_create to create a thread to execute the client_handler
function. In this function, some information will be written to the client. If
the write fails, the thread returns NULL without atomically reducing
num_clients, this will cause the Telemetry server to run for a period of time,
and the value of num_clients will be greater than 10, resulting in telemetry
being unavailable. 
Therefore, the decrease in atomicity v2_clients should occur after the write()
failure