export SOCK_NONBLOCK, SOCK_CLOEXEC constants in Kgio

It's more reliable than relying on IO::NONBLOCK and
Fcntl::FD_CLOEXEC constants.  The existing constants are not
guaranteed to be equivalent to what accept4() takes even
though the current Linux implementation does it this way.

2 files changed, 65 insertions, 4 deletions

diff --git a/ext/kgio/accept.c b/ext/kgio/accept.c
index 1a125ca..f14c791 100644
--- a/ext/kgio/accept.c
+++ b/ext/kgio/accept.c
@@ -283,8 +283,8 @@ static VALUE addr_bang(VALUE io)
  * value of +Kgio.accept_cloexec+ and +Kgio.accept_nonblock+.  +flags+
  * is a bitmask that may contain any combination of:
  *
- * - Fcntl::FD_CLOEXEC - close-on-exec flag
- * - IO::NONBLOCK - non-blocking flag
+ * - Kgio::SOCK_CLOEXEC - close-on-exec flag
+ * - Kgio::SOCK_NONBLOCK - non-blocking flag
  */
 static VALUE tcp_tryaccept(int argc, VALUE *argv, VALUE self)
 {
@@ -320,8 +320,8 @@ static VALUE tcp_tryaccept(int argc, VALUE *argv, VALUE self)
  * value of +Kgio.accept_cloexec+ and +Kgio.accept_nonblock+.  +flags+
  * is a bitmask that may contain any combination of:
  *
- * - Fcntl::FD_CLOEXEC - close-on-exec flag
- * - IO::NONBLOCK - non-blocking flag
+ * - Kgio::SOCK_CLOEXEC - close-on-exec flag
+ * - Kgio::SOCK_NONBLOCK - non-blocking flag
  */
 static VALUE tcp_accept(int argc, VALUE *argv, VALUE self)
 {
@@ -496,6 +496,18 @@ void init_kgio_accept(void)
         VALUE cUNIXServer, cTCPServer;
         VALUE mKgio = rb_define_module("Kgio");
 
+        /*
+         * this maps to the SOCK_NONBLOCK constant in Linux for setting
+         * the non-blocking flag on newly accepted sockets.
+         */
+        rb_define_const(mKgio, "SOCK_NONBLOCK", INT2NUM(SOCK_NONBLOCK));
+
+        /*
+         * this maps to the SOCK_CLOEXEC constant in Linux for setting
+         * the close-on-exec flag on newly accepted descriptors.
+         */
+        rb_define_const(mKgio, "SOCK_CLOEXEC", INT2NUM(SOCK_CLOEXEC));
+
         localhost = rb_const_get(mKgio, rb_intern("LOCALHOST"));
         cKgio_Socket = rb_const_get(mKgio, rb_intern("Socket"));
         cClientSocket = cKgio_Socket;
diff --git a/test/test_accept_flags.rb b/test/test_accept_flags.rb
new file mode 100644
index 0000000..3aae216
--- /dev/null
+++ b/test/test_accept_flags.rb
@@ -0,0 +1,49 @@
+require 'test/unit'
+require 'fcntl'
+require 'io/nonblock'
+$-w = true
+require 'kgio'
+
+class TestAcceptFlags < Test::Unit::TestCase
+  def test_accept_flags
+    @host = ENV["TEST_HOST"] || '127.0.0.1'
+    @srv = Kgio::TCPServer.new(@host, 0)
+    @port = @srv.addr[1]
+
+    client = TCPSocket.new(@host, @port)
+    accepted = @srv.kgio_accept(nil, Kgio::SOCK_NONBLOCK)
+    assert_instance_of Kgio::Socket, accepted
+    assert accepted.nonblock?
+    flags = accepted.fcntl(Fcntl::F_GETFD)
+    assert_equal 0, flags & Fcntl::FD_CLOEXEC
+    assert_nil client.close
+    assert_nil accepted.close
+
+    client = TCPSocket.new(@host, @port)
+    accepted = @srv.kgio_accept(nil, Kgio::SOCK_CLOEXEC)
+    assert_instance_of Kgio::Socket, accepted
+    assert ! accepted.nonblock?
+    flags = accepted.fcntl(Fcntl::F_GETFD)
+    assert_equal Fcntl::FD_CLOEXEC, flags & Fcntl::FD_CLOEXEC
+    assert_nil client.close
+    assert_nil accepted.close
+
+    client = TCPSocket.new(@host, @port)
+    accepted = @srv.kgio_accept(nil, Kgio::SOCK_CLOEXEC|Kgio::SOCK_NONBLOCK)
+    assert_instance_of Kgio::Socket, accepted
+    assert accepted.nonblock?
+    flags = accepted.fcntl(Fcntl::F_GETFD)
+    assert_equal Fcntl::FD_CLOEXEC, flags & Fcntl::FD_CLOEXEC
+    assert_nil client.close
+    assert_nil accepted.close
+
+    client = TCPSocket.new(@host, @port)
+    accepted = @srv.kgio_accept(nil, Kgio::SOCK_CLOEXEC|Kgio::SOCK_NONBLOCK)
+    assert_instance_of Kgio::Socket, accepted
+    assert accepted.nonblock?
+    flags = accepted.fcntl(Fcntl::F_GETFD)
+    assert_equal Fcntl::FD_CLOEXEC, flags & Fcntl::FD_CLOEXEC
+    assert_nil client.close
+    assert_nil accepted.close
+  end
+end