Avoid spawning Threadpool#trim thread if pool size is fixed (#3384)

Co-authored-by: ouyangjinting <OuYangJinTing@users.noreply.github.com>
puma · Nov 23, 2024 · 5f41574 · 5f41574
1 parent 8c4e80d
commit 5f41574
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Showing 2 changed files with 36 additions and 2 deletions.
diff --git a/lib/puma/server.rb b/lib/puma/server.rb
@@ -253,9 +253,8 @@ def run(background=true, thread_name: 'srv')
         @reactor.run
       end
 
-
       @thread_pool.auto_reap! if options[:reaping_time]
-      @thread_pool.auto_trim! if options[:auto_trim_time]
+      @thread_pool.auto_trim! if @min_threads != @max_threads && options[:auto_trim_time]
 
       @check, @notify = Puma::Util.pipe unless @notify
 

diff --git a/test/test_puma_server.rb b/test/test_puma_server.rb
@@ -40,6 +40,8 @@ def server_run(**options, &block)
     @server = Puma::Server.new block || @app, @events, options
     @bind_port = (@server.add_tcp_listener @host, 0).addr[1]
     @server.run
+  ensure
+    @pool = @server.instance_variable_get(:@thread_pool)
   end
 
   def test_http10_req_to_http10_resp
@@ -2098,4 +2100,37 @@ def test_cl_and_te_smuggle
     assert_includes body, "Content-Length: 144\r\n"
     assert_equal 1, response.scan("HTTP/1.1 200 OK").size
   end
+
+  def test_auto_trim_with_variable_pool_size
+    auto_trim_time = 3
+    server_run(min_threads: 1, max_threads: 2, auto_trim_time: auto_trim_time)
+    sleep 1 # wait for possible initial trim on run
+    thread_pool_expect true, :trim, nil, after: auto_trim_time
+  end
+
+  def test_auto_trim_with_fixed_pool_size
+    auto_trim_time = 3
+    server_run(min_threads: 2, max_threads: 2, auto_trim_time: auto_trim_time)
+    sleep 1 # wait for possible initial trim on run
+    thread_pool_expect false, :trim, nil, after: auto_trim_time
+  end
+
+  private
+
+  def thread_pool_expect(should_expect, expect_method, *expect_args, after: nil)
+    mock_pool = Minitest::Mock.new
+    mock_pool.expect(expect_method, *expect_args) if should_expect
+
+    @pool.singleton_class.class_eval do
+      define_method(expect_method) do |*args, **kwargs|
+        raise "unexpected #{expect_method} called on Puma::Threadpool" unless should_expect
+
+        mock_pool.public_send(expect_method, *args, **kwargs)
+      end
+    end
+
+    sleep after if after
+
+    assert mock_pool.verify # assert to satisfy proveit
+  end
 end