remove autopush support and make it a no-op

Maintaining global state in a library like kgio is ugly, and it
is not optimal from a performance standpoint compared to using
MSG_MORE.

TCP_CORK and TCP_NOPUSH require extra syscalls so it still offers
sub-optimal performance compared to MSG_MORE.

Instead, server developers should use MSG_MORE if their OS supports
it (and should add MSG_MORE to their OS if lacking it).

1 files changed, 3 insertions, 157 deletions

diff --git a/test/test_autopush.rb b/test/test_autopush.rb
index 38b7c52..4e5af92 100644
--- a/test/test_autopush.rb
+++ b/test/test_autopush.rb
@@ -1,165 +1,11 @@
-require 'tempfile'
 require 'test/unit'
-begin
-  $-w = false
-  RUBY_PLATFORM =~ /linux/ and require 'strace'
-rescue LoadError
-end
-$-w = true
 require 'kgio'
 
 class TestAutopush < Test::Unit::TestCase
-  TCP_CORK = 3
-  TCP_NOPUSH = 4
-
-  def setup
-    Kgio.autopush = false
-    assert_equal false, Kgio.autopush?
-
-    @host = ENV["TEST_HOST"] || '127.0.0.1'
-    @srv = Kgio::TCPServer.new(@host, 0)
-    RUBY_PLATFORM =~ /linux/ and
-      @srv.setsockopt(Socket::IPPROTO_TCP, TCP_CORK, 1)
-    RUBY_PLATFORM =~ /freebsd/ and
-      @srv.setsockopt(Socket::IPPROTO_TCP, TCP_NOPUSH, 1)
-    @port = @srv.addr[1]
-  end
-
-  def test_autopush_accessors
-    Kgio.autopush = true
-    opt = RUBY_PLATFORM =~ /freebsd/ ? TCP_NOPUSH : TCP_CORK
-    s = Kgio::TCPSocket.new(@host, @port)
-    assert_equal 0, s.getsockopt(Socket::IPPROTO_TCP, opt).unpack('i')[0]
-    assert ! s.kgio_autopush?
-    s.kgio_autopush = true
-    assert s.kgio_autopush?
-    s.kgio_write 'asdf'
-    assert_equal :wait_readable, s.kgio_tryread(1)
-    assert s.kgio_autopush?
-    val = s.getsockopt(Socket::IPPROTO_TCP, opt).unpack('i')[0]
-    assert_operator val, :>, 0, "#{opt}=#{val} (#{RUBY_PLATFORM})"
-  end
-
-  def test_autopush_true_unix
-    Kgio.autopush = true
-    tmp = Tempfile.new('kgio_unix')
-    @path = tmp.path
-    tmp.close!
-    @srv = Kgio::UNIXServer.new(@path)
-    @rd = Kgio::UNIXSocket.new(@path)
-    t0 = nil
-    if defined?(Strace)
-      io, err = Strace.me { @wr = @srv.kgio_accept }
-      assert_nil err
-      rc = nil
-      io, err = Strace.me {
-        t0 = Time.now
-        @wr.kgio_write "HI\n"
-        rc = @wr.kgio_tryread 666
-      }
-      assert_nil err
-      lines = io.readlines
-      assert lines.grep(/TCP_CORK/).empty?, lines.inspect
-    else
-      @wr = @srv.kgio_accept
-      t0 = Time.now
-      @wr.kgio_write "HI\n"
-      rc = @wr.kgio_tryread 666
-    end
-    assert_equal "HI\n", @rd.kgio_read(3)
-    diff = Time.now - t0
-    assert(diff < 0.200, "nopush on UNIX sockets? diff=#{diff} > 200ms")
-    assert_equal :wait_readable, rc
-  ensure
-    File.unlink(@path) rescue nil
-  end
-
-  def test_autopush_false
-    Kgio.autopush = nil
-    assert_equal false, Kgio.autopush?
-
-    @wr = Kgio::TCPSocket.new(@host, @port)
-    if defined?(Strace)
-      io, err = Strace.me { @rd = @srv.kgio_accept }
-      assert_nil err
-      lines = io.readlines
-      assert lines.grep(/TCP_CORK/).empty?, lines.inspect
-      assert_equal 1, @rd.getsockopt(Socket::SOL_TCP, TCP_CORK).unpack("i")[0]
-    else
-      @rd = @srv.kgio_accept
-    end
-
-    rbuf = "..."
-    t0 = Time.now
-    @rd.kgio_write "HI\n"
-    @wr.kgio_read(3, rbuf)
-    diff = Time.now - t0
-    assert(diff >= 0.190, "nopush broken? diff=#{diff} > 200ms")
-    assert_equal "HI\n", rbuf
-  end
-
-  def test_autopush_true
+  def test_compatibility
     Kgio.autopush = true
     assert_equal true, Kgio.autopush?
-    @wr = Kgio::TCPSocket.new(@host, @port)
-
-    if defined?(Strace)
-      io, err = Strace.me { @rd = @srv.kgio_accept }
-      assert_nil err
-      lines = io.readlines
-      assert_equal 1, lines.grep(/TCP_CORK/).size, lines.inspect
-      assert_equal 1, @rd.getsockopt(Socket::SOL_TCP, TCP_CORK).unpack("i")[0]
-    else
-      @rd = @srv.kgio_accept
-    end
-
-    @wr.write "HI\n"
-    rbuf = ""
-    if defined?(Strace)
-      io, err = Strace.me { @rd.kgio_read(3, rbuf) }
-      assert_nil err
-      lines = io.readlines
-      assert lines.grep(/TCP_CORK/).empty?, lines.inspect
-      assert_equal "HI\n", rbuf
-    else
-      assert_equal "HI\n", @rd.kgio_read(3, rbuf)
-    end
-
-    t0 = Time.now
-    @rd.kgio_write "HI2U2\n"
-    @rd.kgio_write "HOW\n"
-    rc = false
-
-    if defined?(Strace)
-      io, err = Strace.me { rc = @rd.kgio_tryread(666) }
-    else
-      rc = @rd.kgio_tryread(666)
-    end
-
-    @wr.readpartial(666, rbuf)
-    rbuf == "HI2U2\nHOW\n" or warn "rbuf=#{rbuf.inspect} looking bad?"
-    diff = Time.now - t0
-    assert(diff < 0.200, "time diff=#{diff} >= 200ms")
-    assert_equal :wait_readable, rc
-    if defined?(Strace)
-      assert_nil err
-      lines = io.readlines
-      assert_equal 2, lines.grep(/TCP_CORK/).size, lines.inspect
-    end
-    @wr.close
-    @rd.close
-
-    @wr = Kgio::TCPSocket.new(@host, @port)
-    if defined?(Strace)
-      io, err = Strace.me { @rd = @srv.kgio_accept }
-      assert_nil err
-      lines = io.readlines
-      assert lines.grep(/TCP_CORK/).empty?,"optimization fail: #{lines.inspect}"
-      assert_equal 1, @rd.getsockopt(Socket::SOL_TCP, TCP_CORK).unpack("i")[0]
-    end
-  end
-
-  def teardown
     Kgio.autopush = false
+    assert_equal false, Kgio.autopush?
   end
-end if RUBY_PLATFORM =~ /linux|freebsd/
+end