Make acl_fiber_kill() more safety.

lib_acl/src/master/template/acl_aio_server.c

@@ -925,9 +925,9 @@ static void dispatch_receive(int event_type acl_unused, ACL_EVENT *event,
 
 	ret = acl_read_fd(ACL_VSTREAM_SOCK(conn), buf, sizeof(buf) - 1, &fd);
 	if (ret <= 0 || fd < 0) {
-		acl_msg_warn("%s(%d), %s: read from master_dispatch(%s) error",
+		acl_msg_warn("%s(%d), %s: read from master_dispatch(%s) error %s",
 			__FUNCTION__, __LINE__, myname,
-			acl_var_aio_dispatch_addr);
+			acl_var_aio_dispatch_addr, acl_last_serror());
 
 		acl_event_disable_read(event, conn);
 		acl_vstream_close(conn);

lib_fiber/c/src/fiber_io.c

@@ -432,8 +432,10 @@ static void read_callback(EVENT *ev, FILE_EVENT *fe)
 	/* If the reader fiber has been set in ready status when the
 	 * other fiber killed the reader fiber, the reader fiber should
 	 * not be set in ready queue again.
+	 * We should check if fe->fiber_r is NULL, which maybe set NULL if
+	 * the other fiber acl_fiber_kill() the fiber_r before.
 	 */
-	if (fe->fiber_r->status != FIBER_STATUS_READY) {
+	if (fe->fiber_r && fe->fiber_r->status != FIBER_STATUS_READY) {
 		acl_fiber_ready(fe->fiber_r);
 	}
 }
@@ -497,7 +499,7 @@ static void write_callback(EVENT *ev, FILE_EVENT *fe)
 	 * other fiber killed the writer fiber, the writer fiber should
 	 * not be set in ready queue again.
 	 */
-	if (fe->fiber_w->status != FIBER_STATUS_READY) {
+	if (fe->fiber_w && fe->fiber_w->status != FIBER_STATUS_READY) {
 		acl_fiber_ready(fe->fiber_w);
 	}
 }