perf: prevent redundant context switch (#152)

Author: supercaracal

lib/redis_client/cluster/node.rb

@@ -85,7 +85,6 @@ def load_info(options, **kwargs) # rubocop:disable Metrics/AbcSize, Metrics/Cycl
           startup_nodes.each_slice(MAX_THREADS).with_index do |chuncked_startup_nodes, chuncked_idx|
             threads = chuncked_startup_nodes.each_with_index.map do |raw_client, idx|
               Thread.new(raw_client, (MAX_THREADS * chuncked_idx) + idx) do |cli, i|
-                Thread.pass
                 Thread.current.thread_variable_set(:index, i)
                 reply = cli.call('CLUSTER', 'NODES')
                 Thread.current.thread_variable_set(:info, parse_cluster_node_reply(reply))
@@ -304,7 +303,6 @@ def try_map(clients) # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComple
         clients.each_slice(MAX_THREADS) do |chuncked_clients|
           threads = chuncked_clients.map do |k, v|
             Thread.new(k, v) do |node_key, client|
-              Thread.pass
               Thread.current.thread_variable_set(:node_key, node_key)
               reply = yield(node_key, client)
               Thread.current.thread_variable_set(:result, reply)

lib/redis_client/cluster/node/latency_replica.rb

@@ -43,7 +43,6 @@ def measure_latencies(clients) # rubocop:disable Metrics/AbcSize
           clients.each_slice(::RedisClient::Cluster::Node::MAX_THREADS).each_with_object({}) do |chuncked_clients, acc|
             threads = chuncked_clients.map do |k, v|
               Thread.new(k, v) do |node_key, client|
-                Thread.pass
                 Thread.current.thread_variable_set(:node_key, node_key)
 
                 min = DUMMY_LATENCY_NSEC

test/cluster_controller.rb

@@ -197,7 +197,6 @@ def scale_in # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedCo
     primary = primary_info.client
     threads = @clients.map do |cli|
       Thread.new(cli) do |c|
-        Thread.pass
         c.pipelined do |pi|
           pi.call('CLUSTER', 'FORGET', replica_info.id)
           pi.call('CLUSTER', 'FORGET', primary_info.id)

test/redis_client/cluster/test_normalized_cmd_name.rb

@@ -67,7 +67,6 @@ def test_thread_safety
 
         threads = attempts.each_with_index.map do |_, i|
           Thread.new do
-            Thread.pass
             Thread.current.thread_variable_set(:index, i)
             got = if i.even?
                     @subject.get_by_command(%w[SET foo bar])

test/test_concurrency.rb

@@ -53,9 +53,7 @@ def test_forking_with_pipelining
   def test_threading
     threads = Array.new(MAX_THREADS) do
       Thread.new do
-        Thread.pass
         ATTEMPTS.times { MAX_THREADS.times { |i| @client.call('INCR', "key#{i}") } }
-        Thread.pass
         ATTEMPTS.times { MAX_THREADS.times { |i| @client.call('DECR', "key#{i}") } }
       rescue StandardError => e
         Thread.current.thread_variable_set(:error, e)
@@ -70,9 +68,7 @@ def test_threading
   def test_threading_with_pipelining
     threads = Array.new(MAX_THREADS) do
       Thread.new do
-        Thread.pass
         @client.pipelined { |pi| ATTEMPTS.times { MAX_THREADS.times { |i| pi.call('INCR', "key#{i}") } } }
-        Thread.pass
         @client.pipelined { |pi| ATTEMPTS.times { MAX_THREADS.times { |i| pi.call('DECR', "key#{i}") } } }
       rescue StandardError => e
         Thread.current.thread_variable_set(:error, e)