cleanup graceful shutdown handling

Using a 10ms tick was too little, use 100ms instead to avoid
burning CPU.  Ideally, we would not tick at all during shutdown
(we're normally tickless); but the common case could be
slightly more expensive; and shutdowns are rare (I hope).

Then, change our process title to indicate we're shutting down,
and finally, cut down on repeated log spew during shutdown and
only log dropping changes.

This mean we could potentially take 90ms longer to notice when
we can do a graceful shutdown, but oh well...

While we're at it, add a test to ensure graceful shutdowns
work as intended with multiple processes.

1 files changed, 35 insertions, 0 deletions

diff --git a/test/test_server.rb b/test/test_server.rb
index 9f33b42..c6d70cb 100644
--- a/test/test_server.rb
+++ b/test/test_server.rb
@@ -725,6 +725,41 @@ class TestServer < Testcase
     assert_nil c.read(666)
   end
 
+  def test_slow_shutdown_timeout; _slow_shutdown(nil); end
+  def test_slow_shutdown_timeout_mp; _slow_shutdown(1); end
+
+  def _slow_shutdown(nr_workers)
+    err, cfg, host, port = @err, Yahns::Config.new, @srv.addr[3], @srv.addr[1]
+    pid = mkserver(cfg) do
+      ru = lambda { |e| [ 200, {'Content-Length'=>'2'}, %w(OK) ] }
+      cfg.instance_eval do
+        app(:rack, ru) { listen "#{host}:#{port}" }
+        stderr_path err.path
+        worker_processes(nr_workers) if nr_workers
+      end
+    end
+    c = get_tcp_client(host, port)
+    c.write 'G'
+    100000.times { Thread.pass }
+    Process.kill(:QUIT, pid)
+    "ET / HTTP/1.1\r\nHost: example.com\r\n\r\n".each_byte do |x|
+      Thread.pass
+      c.write(x.chr)
+      Thread.pass
+    end
+    assert_equal c, c.wait(30)
+    buf = ''.dup
+    re = /\r\n\r\nOK\z/
+    Timeout.timeout(30) do
+      begin
+        buf << c.readpartial(666)
+      end until re =~ buf
+    end
+    c.close
+    _, status = Timeout.timeout(5) { Process.waitpid2(pid) }
+    assert status.success?, status.inspect
+  end
+
   def test_before_exec
     err, cfg, host, port = @err, Yahns::Config.new, @srv.addr[3], @srv.addr[1]
     ru = lambda { |e| [ 200, {'Content-Length'=>'2' }, %w(OK) ] }