diff --git a/Makefile b/Makefile
index 7db3749..b6355eb 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,8 @@ endif
 COLIB_OBJS=co_epoll.o co_routine.o co_hook_sys_call.o coctx_swap.o coctx.o
 #co_swapcontext.o
 
-PROGS = colib example_poll example_echosvr example_echocli example_thread  example_cond example_specific example_copystack example_closure
+PROGS = colib example_poll example_echosvr example_echocli example_thread  example_cond \
+		example_specific example_copystack example_closure example_setenv
 
 all:$(PROGS)
 
diff --git a/example_poll.cpp b/example_poll.cpp
index eb92f21..0043895 100644
--- a/example_poll.cpp
+++ b/example_poll.cpp
@@ -135,9 +135,14 @@ static void *poll_routine( void *arg )
 		int ret = poll( pf,iWaitCnt,1000 );
 		printf("co %p poll wait %ld ret %d\n",
 				co_self(),iWaitCnt,ret);
+		int nready = ret; 
 		for(int i=0;i<(int)iWaitCnt;i++)
 		{
-			printf("co %p fire fd %d revents 0x%X POLLOUT 0x%X POLLERR 0x%X POLLHUP 0x%X\n",
+			if ( nready <= 0 )
+				break;
+			if (pf[i].revents & (POLLOUT | POLLERR | POLLHUP)) 
+			{
+				printf("co %p fire fd %d revents 0x%X POLLOUT 0x%X POLLERR 0x%X POLLHUP 0x%X\n",
 					co_self(),
 					pf[i].fd,
 					pf[i].revents,
@@ -145,13 +150,15 @@ static void *poll_routine( void *arg )
 					POLLERR,
 					POLLHUP
 					);
-			setRaiseFds.insert( pf[i].fd );
+				setRaiseFds.insert( pf[i].fd );
+				nready--;
+			}
 		}
 		if( setRaiseFds.size() == v.size())
 		{
 			break;
 		}
-		if( ret <= 0 )
+		if( ret < 0 )
 		{
 			break;
 		}