accept_nonblock supports "exception: false"

This is analogous to functionality found in IO#read_nonblock and
IO#wait_nonblock.  Raising exceptions for common failures on
non-blocking servers is expensive and makes $DEBUG too noisy.

Benchmark results:
                                    user     system      total        real
default                         2.790000   0.870000   3.660000 (  3.671597)
exception: false                1.120000   0.800000   1.920000 (  1.922032)
exception: false (cached arg)   0.820000   0.770000   1.590000 (  1.589267)
--------------------- benchmark script ------------------------
require 'socket'
require 'benchmark'
require 'tmpdir'
nr = 1000000
Dir.mktmpdir('nb_bench') do |path|
  sock_path = "#{path}/test.sock"
  s = UNIXServer.new(sock_path)
  Benchmark.bmbm do |x|
    x.report("default") do
      nr.times do
        begin
          s.accept_nonblock
        rescue IO::WaitReadable
        end
      end
    end
    x.report("exception: false") do
      nr.times do
        begin
          s.accept_nonblock(exception: false)
        rescue IO::WaitReadable
          abort "should not raise"
        end
      end
    end
    x.report("exception: false (cached arg)") do
      arg = { exception: false }
      nr.times do
        begin
          s.accept_nonblock(arg)
        rescue IO::WaitReadable
          abort "should not raise"
        end
      end
    end
  end
end

* ext/socket/init.c (rsock_s_accept_nonblock):
  support exception: false
  [ruby-core:66385] [Feature #10532]
* ext/socket/init.c (rsock_init_socket_init): define new symbols
* ext/socket/rubysocket.h: adjust prototype
* ext/socket/socket.c (sock_accept_nonblock): support exception: false
* ext/openssl/ossl_ssl.c (ossl_ssl_accept_nonblock): ditto
* ext/socket/socket.c (Init_socket): adjust accept_nonblock definition
* ext/openssl/ossl_ssl.c (Init_ossl_ssl): ditto
* ext/socket/tcpserver.c (rsock_init_tcpserver): ditto
* ext/socket/unixserver.c (rsock_init_unixserver): ditto
* ext/socket/tcpserver.c (tcp_accept_nonblock): adjust
  rsock_s_accept_nonblock call
* ext/socket/unixserver.c (unix_accept_nonblock): ditto
* ext/openssl/ossl_ssl.c (ossl_start_ssl): support no_exception
* ext/openssl/ossl_ssl.c (ossl_ssl_connect): adjust ossl_start_ssl call
* ext/openssl/ossl_ssl.c (ossl_ssl_connect_nonblock): ditto
* ext/openssl/ossl_ssl.c (ossl_ssl_accept): ditto
* test/socket/test_nonblock.rb (test_accept_nonblock): test for
  "exception :false"
* test/socket/test_tcp.rb (test_accept_nonblock): new test
* test/socket/test_unix.rb (test_accept_nonblock): ditto
* test/openssl/test_pair.rb (test_accept_nonblock_no_exception): ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49948 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 44 insertions, 0 deletions

diff --git a/test/openssl/test_pair.rb b/test/openssl/test_pair.rb
index 3aca5f4833..2c2776b644 100644
--- a/test/openssl/test_pair.rb
+++ b/test/openssl/test_pair.rb
@@ -283,6 +283,33 @@ module OpenSSL::TestPairM
     serv.close if serv && !serv.closed?
   end
 
+  def test_accept_nonblock_no_exception
+    ctx2 = OpenSSL::SSL::SSLContext.new
+    ctx2.ciphers = "ADH"
+    ctx2.tmp_dh_callback = proc { OpenSSL::TestUtils::TEST_KEY_DH1024 }
+
+    sock1, sock2 = tcp_pair
+
+    s2 = OpenSSL::SSL::SSLSocket.new(sock2, ctx2)
+    accepted = s2.accept_nonblock(exception: false)
+    assert_equal :wait_readable, accepted
+
+    ctx1 = OpenSSL::SSL::SSLContext.new
+    ctx1.ciphers = "ADH"
+    s1 = OpenSSL::SSL::SSLSocket.new(sock1, ctx1)
+    th = Thread.new { s1.connect }
+    until th.join(0.01)
+      accepted = s2.accept_nonblock(exception: false)
+      assert_includes([s2, :wait_readable, :wait_writable ], accepted)
+    end
+  ensure
+    s1.close if s1
+    s2.close if s2
+    sock1.close if sock1
+    sock2.close if sock2
+    accepted.close if accepted.respond_to?(:close)
+  end
+
   def test_connect_accept_nonblock
     ctx = OpenSSL::SSL::SSLContext.new()
     ctx.ciphers = "ADH"
diff --git a/test/socket/test_nonblock.rb b/test/socket/test_nonblock.rb
index 882e438deb..94ed198616 100644
--- a/test/socket/test_nonblock.rb
+++ b/test/socket/test_nonblock.rb
@@ -13,6 +13,8 @@ class TestSocketNonblock < Test::Unit::TestCase
     serv.bind(Socket.sockaddr_in(0, "127.0.0.1"))
     serv.listen(5)
     assert_raise(IO::WaitReadable) { serv.accept_nonblock }
+    assert_equal :wait_readable, serv.accept_nonblock(exception: false)
+    assert_raise(IO::WaitReadable) { serv.accept_nonblock(exception: true) }
     c = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM, 0)
     c.connect(serv.getsockname)
     begin
diff --git a/test/socket/test_tcp.rb b/test/socket/test_tcp.rb
index 7328897d1e..a6c332c6c4 100644
--- a/test/socket/test_tcp.rb
+++ b/test/socket/test_tcp.rb
@@ -76,4 +76,12 @@ class TestSocket_TCPSocket < Test::Unit::TestCase
       th.join
     }
   end
+
+  def test_accept_nonblock
+    TCPServer.open("localhost", 0) {|svr|
+      assert_raises(IO::WaitReadable) { svr.accept_nonblock }
+      assert_equal :wait_readable, svr.accept_nonblock(exception: false)
+      assert_raises(IO::WaitReadable) { svr.accept_nonblock(exception: true) }
+    }
+  end
 end if defined?(TCPSocket)
diff --git a/test/socket/test_unix.rb b/test/socket/test_unix.rb
index 866c83906e..829eaa90a2 100644
--- a/test/socket/test_unix.rb
+++ b/test/socket/test_unix.rb
@@ -663,4 +663,11 @@ class TestSocket_UNIXSocket < Test::Unit::TestCase
     assert(s0.closed?)
   end
 
+  def test_accept_nonblock
+    bound_unix_socket(UNIXServer) {|serv, path|
+      assert_raises(IO::WaitReadable) { serv.accept_nonblock }
+      assert_raises(IO::WaitReadable) { serv.accept_nonblock(exception: true) }
+      assert_equal :wait_readable, serv.accept_nonblock(exception: false)
+    }
+  end
 end if defined?(UNIXSocket) && /cygwin/ !~ RUBY_PLATFORM