diff options
Diffstat (limited to 'src/ruby/lib/grpc/generic/rpc_server.rb')
| -rw-r--r-- | src/ruby/lib/grpc/generic/rpc_server.rb | 171 |
1 files changed, 141 insertions, 30 deletions
diff --git a/src/ruby/lib/grpc/generic/rpc_server.rb b/src/ruby/lib/grpc/generic/rpc_server.rb index 7dbcb7d479..00e0db71be 100644 --- a/src/ruby/lib/grpc/generic/rpc_server.rb +++ b/src/ruby/lib/grpc/generic/rpc_server.rb @@ -31,10 +31,133 @@ require_relative '../grpc' require_relative 'active_call' require_relative 'service' require 'thread' -require 'concurrent' # GRPC contains the General RPC module. module GRPC + # Pool is a simple thread pool. + class Pool + # Default keep alive period is 1s + DEFAULT_KEEP_ALIVE = 1 + + def initialize(size, keep_alive: DEFAULT_KEEP_ALIVE) + fail 'pool size must be positive' unless size > 0 + @jobs = Queue.new + @size = size + @stopped = false + @stop_mutex = Mutex.new # needs to be held when accessing @stopped + @stop_cond = ConditionVariable.new + @workers = [] + @keep_alive = keep_alive + + # Each worker thread has its own queue to push and pull jobs + # these queues are put into @ready_queues when that worker is idle + @ready_workers = Queue.new + end + + # Returns the number of jobs waiting + def jobs_waiting + @jobs.size + end + + def ready_for_work? + # Busy worker threads are either doing work, or have a single job + # waiting on them. Workers that are idle with no jobs waiting + # have their "queues" in @ready_workers + !@ready_workers.empty? + end + + # Runs the given block on the queue with the provided args. + # + # @param args the args passed blk when it is called + # @param blk the block to call + def schedule(*args, &blk) + return if blk.nil? + @stop_mutex.synchronize do + if @stopped + GRPC.logger.warn('did not schedule job, already stopped') + return + end + GRPC.logger.info('schedule another job') + fail 'No worker threads available' if @ready_workers.empty? + worker_queue = @ready_workers.pop + + fail 'worker already has a task waiting' unless worker_queue.empty? + worker_queue << [blk, args] + end + end + + # Starts running the jobs in the thread pool. + def start + @stop_mutex.synchronize do + fail 'already stopped' if @stopped + end + until @workers.size == @size.to_i + new_worker_queue = Queue.new + @ready_workers << new_worker_queue + next_thread = Thread.new(new_worker_queue) do |jobs| + catch(:exit) do # allows { throw :exit } to kill a thread + loop_execute_jobs(jobs) + end + remove_current_thread + end + @workers << next_thread + end + end + + # Stops the jobs in the pool + def stop + GRPC.logger.info('stopping, will wait for all the workers to exit') + schedule { throw :exit } while ready_for_work? + @stop_mutex.synchronize do # wait @keep_alive for works to stop + @stopped = true + @stop_cond.wait(@stop_mutex, @keep_alive) if @workers.size > 0 + end + forcibly_stop_workers + GRPC.logger.info('stopped, all workers are shutdown') + end + + protected + + # Forcibly shutdown any threads that are still alive. + def forcibly_stop_workers + return unless @workers.size > 0 + GRPC.logger.info("forcibly terminating #{@workers.size} worker(s)") + @workers.each do |t| + next unless t.alive? + begin + t.exit + rescue StandardError => e + GRPC.logger.warn('error while terminating a worker') + GRPC.logger.warn(e) + end + end + end + + # removes the threads from workers, and signal when all the + # threads are complete. + def remove_current_thread + @stop_mutex.synchronize do + @workers.delete(Thread.current) + @stop_cond.signal if @workers.size.zero? + end + end + + def loop_execute_jobs(worker_queue) + loop do + begin + blk, args = worker_queue.pop + blk.call(*args) + rescue StandardError => e + GRPC.logger.warn('Error in worker thread') + GRPC.logger.warn(e) + end + # there shouldn't be any work given to this thread while its busy + fail('received a task while busy') unless worker_queue.empty? + @ready_workers << worker_queue + end + end + end + # RpcServer hosts a number of services and makes them available on the # network. class RpcServer @@ -44,14 +167,11 @@ module GRPC def_delegators :@server, :add_http2_port - # Default max size of the thread pool size is 100 - DEFAULT_MAX_POOL_SIZE = 100 - - # Default minimum size of the thread pool is 5 - DEFAULT_MIN_POOL_SIZE = 5 + # Default thread pool size is 30 + DEFAULT_POOL_SIZE = 30 - # Default max_waiting_requests size is 60 - DEFAULT_MAX_WAITING_REQUESTS = 60 + # Deprecated due to internal changes to the thread pool + DEFAULT_MAX_WAITING_REQUESTS = 20 # Default poll period is 1s DEFAULT_POLL_PERIOD = 1 @@ -74,12 +194,12 @@ module GRPC # There are some specific keyword args used to configure the RpcServer # instance. # - # * pool_size: the maximum size of the thread pool that the server's - # thread pool can reach. + # * pool_size: the size of the thread pool the server uses to run its + # threads. No more concurrent requests can be made than the size + # of the thread pool # - # * max_waiting_requests: the maximum number of requests that are not - # being handled to allow. When this limit is exceeded, the server responds - # with not available to new requests + # * max_waiting_requests: Deprecated due to internal changes to the thread + # pool. This is still an argument for compatibility but is ignored. # # * poll_period: when present, the server polls for new events with this # period @@ -91,8 +211,7 @@ module GRPC # # * server_args: # A server arguments hash to be passed down to the underlying core server - def initialize(pool_size:DEFAULT_MAX_POOL_SIZE, - min_pool_size:DEFAULT_MIN_POOL_SIZE, + def initialize(pool_size:DEFAULT_POOL_SIZE, max_waiting_requests:DEFAULT_MAX_WAITING_REQUESTS, poll_period:DEFAULT_POLL_PERIOD, connect_md_proc:nil, @@ -100,12 +219,8 @@ module GRPC @connect_md_proc = RpcServer.setup_connect_md_proc(connect_md_proc) @max_waiting_requests = max_waiting_requests @poll_period = poll_period - - @pool = Concurrent::ThreadPoolExecutor.new( - min_threads: [min_pool_size, pool_size].min, - max_threads: pool_size, - max_queue: max_waiting_requests, - fallback_policy: :discard) + @pool_size = pool_size + @pool = Pool.new(@pool_size) @run_cond = ConditionVariable.new @run_mutex = Mutex.new # running_state can take 4 values: :not_started, :running, :stopping, and @@ -126,8 +241,7 @@ module GRPC end deadline = from_relative_time(@poll_period) @server.close(deadline) - @pool.shutdown - @pool.wait_for_termination + @pool.stop end def running_state @@ -224,6 +338,7 @@ module GRPC def run @run_mutex.synchronize do fail 'cannot run without registering services' if rpc_descs.size.zero? + @pool.start @server.start transition_running_state(:running) @run_cond.broadcast @@ -235,12 +350,8 @@ module GRPC # Sends RESOURCE_EXHAUSTED if there are too many unprocessed jobs def available?(an_rpc) - jobs_count, max = @pool.queue_length, @pool.max_queue - GRPC.logger.info("waiting: #{jobs_count}, max: #{max}") - - # remaining capacity for ThreadPoolExecutors is -1 if unbounded - return an_rpc if @pool.remaining_capacity != 0 - GRPC.logger.warn("NOT AVAILABLE: too many jobs_waiting: #{an_rpc}") + return an_rpc if @pool.ready_for_work? + GRPC.logger.warn('no free worker threads currently') noop = proc { |x| x } # Create a new active call that knows that metadata hasn't been @@ -275,7 +386,7 @@ module GRPC break if (!an_rpc.nil?) && an_rpc.call.nil? active_call = new_active_server_call(an_rpc) unless active_call.nil? - @pool.post(active_call) do |ac| + @pool.schedule(active_call) do |ac| c, mth = ac begin rpc_descs[mth].run_server_method(c, rpc_handlers[mth]) |