diff --git a/moo/kernel/Socket.moo b/moo/kernel/Socket.moo
index 8a0a1c8..fb32401 100644
--- a/moo/kernel/Socket.moo
+++ b/moo/kernel/Socket.moo
@@ -7,6 +7,7 @@ class Socket(Object) from 'sck'
 	method(#primitive) open(domain, type, proto).
 	method(#primitive) _close.
 	method(#primitive) connect(a,b,c).
+	method(#primitive) endConnect: xxx.
 }
 
 (* TODO: generate these domain and type from the C header *)
@@ -68,6 +69,7 @@ extend Socket
 			System addAsyncSemaphore: s2.
 			self connect(1, 2, 3).
 		] ifCurtailed: [
+			## rollback 
 			sa value: s2.
 		]
 	}
@@ -116,6 +118,7 @@ class MyObject(Object)
 				##s beginRead: xxx.
 				if (result)
 				{
+					s endConnect: result.
 					'CONNECTED NOW.............' dump.
 					s asyncRead: [:data |
 						data dump.
diff --git a/moo/lib/err.c b/moo/lib/err.c
index a8eb5ae..468b0bf 100644
--- a/moo/lib/err.c
+++ b/moo/lib/err.c
@@ -308,7 +308,7 @@ const moo_ooch_t* moo_geterrmsg (moo_t* moo)
 void moo_seterrwithsyserr (moo_t* moo, int syserr)
 {
 	moo_bch_t msgbuf[64];
-	strerror_r (errno, msgbuf, MOO_COUNTOF(msgbuf));
+	strerror_r (syserr, msgbuf, MOO_COUNTOF(msgbuf));
 	moo_seterrbfmt (moo, moo_syserr_to_errnum(errno), "%s", msgbuf);
 }
 
diff --git a/moo/lib/main.c b/moo/lib/main.c
index b75da65..4181391 100644
--- a/moo/lib/main.c
+++ b/moo/lib/main.c
@@ -1666,6 +1666,7 @@ static void vm_muxwait (moo_t* moo, const moo_ntime_t* dur, moo_vmprim_muxwait_c
 				if (revents & XPOLLERR) mask |= MOO_SEMAPHORE_IO_MASK_ERROR;
 				if (revents & XPOLLHUP) mask |= MOO_SEMAPHORE_IO_MASK_HANGUP;
 
+printf ("먹스 마스크  %d\n", (int)mask);
 			#if defined(USE_DEVPOLL)
 				MOO_ASSERT (moo, xtn->epd.capa > xtn->ev.buf[n].fd);
 				muxwcb (moo, mask, (void*)xtn->epd.ptr[xtn->ev.buf[n].fd]);
diff --git a/moo/mod/sck.c b/moo/mod/sck.c
index cf810be..67952e6 100644
--- a/moo/mod/sck.c
+++ b/moo/mod/sck.c
@@ -152,12 +152,55 @@ sin.sin_port = htons(12345);
 	return MOO_PF_SUCCESS;
 
 oops_syserr:
-	errnum = moo_syserr_to_errnum(errno);
+	moo_seterrwithsyserr (moo, errno);
+	return MOO_PF_FAILURE;
 
 oops:
 	moo_seterrnum (moo, errnum);
 	return MOO_PF_FAILURE;
 }
+
+static moo_pfrc_t pf_end_connect (moo_t* moo, moo_ooi_t nargs)
+{
+	oop_sck_t sck;
+	int fd;
+
+	sck = (oop_sck_t)MOO_STACK_GETRCV(moo, nargs);
+	MOO_PF_CHECK_RCV (moo, 
+		MOO_OOP_IS_POINTER(sck) && 
+		MOO_OBJ_BYTESOF(sck) >= (MOO_SIZEOF(*sck) - MOO_SIZEOF(moo_obj_t)) &&
+		MOO_OOP_IS_SMOOI(sck->handle)
+	);
+
+	fd = MOO_OOP_TO_SMOOI(sck->handle);
+	if (fd >= 0)
+	{
+		socklen_t len;
+		int ret;
+
+		len = MOO_SIZEOF(ret);
+		if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (char*)&ret, &len) == -1)
+		{
+			moo_seterrwithsyserr (moo, errno);
+			return MOO_PF_FAILURE;
+		}
+
+		if (ret == EINPROGRESS)
+		{
+			return MOO_PF_FAILURE;
+		}
+		else if (ret != 0)
+		{
+			moo_seterrwithsyserr (moo, ret);
+			return MOO_PF_FAILURE;
+		}
+	}
+
+
+	MOO_STACK_SETRETTORCV (moo, nargs);
+	return MOO_PF_SUCCESS;
+}
+
 /* ------------------------------------------------------------------------ */
  
 typedef struct fnctab_t fnctab_t;
@@ -176,9 +219,10 @@ struct fnctab_t
 
 static moo_pfinfo_t pfinfos[] =
 {
-	{ I, { 'c','l','o','s','e','\0' },          0, { pf_close_socket,    0, 0  }  },
-	{ I, { 'c','o','n','n','e','c','t','\0' },  0, { pf_connect,         3, 3  }  },
-	{ I, { 'o','p','e','n','\0' },              0, { pf_open_socket,     3, 3  }  },
+	{ I, { 'c','l','o','s','e','\0' },                          0, { pf_close_socket,    0, 0  }  },
+	{ I, { 'c','o','n','n','e','c','t','\0' },                  0, { pf_connect,         3, 3  }  },
+	{ I, { 'e','n','d','C','o','n','n','e','c','t',':','\0' },  0, { pf_end_connect,     1, 1  }  },
+	{ I, { 'o','p','e','n','\0' },                              0, { pf_open_socket,     3, 3  }  },
 };
 
 /* ------------------------------------------------------------------------ */