Improve fd_sets handling. Based on a previous patch from Holger Eitzenberger.

diff --git a/src/select.c b/src/select.c
index b1cdb17ec4a886bae1924addb3d1bf666de0cf1c..aaca5172fdeb2041c432fdfd95554357bd89ed3f 100644 (file)
--- a/src/select.c
+++ b/src/select.c
@@ -26,6 +26,7 @@
 #include <ulogd/linuxlist.h>
 
 static int maxfd = 0;
+static fd_set readset, writeset, exceptset;
 static LLIST_HEAD(ulogd_fds);
 
 int ulogd_register_fd(struct ulogd_fd *fd)
@@ -41,6 +42,15 @@ int ulogd_register_fd(struct ulogd_fd *fd)
        if (flags < 0)
                return -1;
 
+       if (fd->when & ULOGD_FD_READ)
+               FD_SET(fd->fd, &readset);
+
+       if (fd->when & ULOGD_FD_WRITE)
+               FD_SET(fd->fd, &writeset);
+
+       if (fd->when & ULOGD_FD_EXCEPT)
+               FD_SET(fd->fd, &exceptset);
+
        /* Register FD */
        if (fd->fd > maxfd)
                maxfd = fd->fd;
@@ -52,44 +62,48 @@ int ulogd_register_fd(struct ulogd_fd *fd)
 
 void ulogd_unregister_fd(struct ulogd_fd *fd)
 {
+       if (fd->when & ULOGD_FD_READ)
+               FD_CLR(fd->fd, &readset);
+
+       if (fd->when & ULOGD_FD_WRITE)
+               FD_CLR(fd->fd, &writeset);
+
+       if (fd->when & ULOGD_FD_EXCEPT)
+               FD_CLR(fd->fd, &exceptset);
+
        llist_del(&fd->list);
+
+       /* Improvement: recalculate maxfd iif fd->fd == maxfd */
+       maxfd = -1;
+       llist_for_each_entry(fd, &ulogd_fds, list) {
+               if (fd->fd > maxfd)
+                       maxfd = fd->fd;
+       }
 }
 
 int ulogd_select_main(struct timeval *tv)
 {
        struct ulogd_fd *ufd;
-       fd_set readset, writeset, exceptset;
+       fd_set rds_tmp, wrs_tmp, exs_tmp;
        int i;
 
-       FD_ZERO(&readset);
-       FD_ZERO(&writeset);
-       FD_ZERO(&exceptset);
-
-       /* prepare read and write fdsets */
-       llist_for_each_entry(ufd, &ulogd_fds, list) {
-               if (ufd->when & ULOGD_FD_READ)
-                       FD_SET(ufd->fd, &readset);
-
-               if (ufd->when & ULOGD_FD_WRITE)
-                       FD_SET(ufd->fd, &writeset);
-
-               if (ufd->when & ULOGD_FD_EXCEPT)
-                       FD_SET(ufd->fd, &exceptset);
-       }
+       rds_tmp = readset;
+       wrs_tmp = writeset;
+       exs_tmp = exceptset;
 
-       i = select(maxfd+1, &readset, &writeset, &exceptset, tv);
+       i = select(maxfd+1, &rds_tmp, &wrs_tmp, &exs_tmp, tv);
        if (i > 0) {
                /* call registered callback functions */
                llist_for_each_entry(ufd, &ulogd_fds, list) {
                        int flags = 0;
 
-                       if (FD_ISSET(ufd->fd, &readset))
+                       if (FD_ISSET(ufd->fd, &rds_tmp))
                                flags |= ULOGD_FD_READ;
 
-                       if (FD_ISSET(ufd->fd, &writeset))
+                       if (FD_ISSET(ufd->fd, &wrs_tmp))
                                flags |= ULOGD_FD_WRITE;
 
-                       if (FD_ISSET(ufd->fd, &exceptset))
+                       if (FD_ISSET(ufd->fd, &exs_tmp))
                                flags |= ULOGD_FD_EXCEPT;
 
                        if (flags)