irqtop: simplify terminal resizing

* don't care about term size and attrs when runs only once
* explicitly define signals
* resize immediately after SIGWINCH (to keep it nice for users)

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/irqtop.c b/sys-utils/irqtop.c
index a9cff2c1a08633712122bd4047a350cc3e79761a..e678f90666e046f0764e40a518f7f4cc2f0b0112 100644 (file)
--- a/sys-utils/irqtop.c
+++ b/sys-utils/irqtop.c
@@ -116,7 +116,6 @@ struct irqtop_ctl {
        WINDOW *win;
        int cols;
        int rows;
-       int old_rows;
        struct itimerspec timer;
        struct timeval uptime_tv;
        sort_fp *sort_func;
@@ -488,10 +487,6 @@ static int update_screen(struct irqtop_ctl *const ctl)
                return 1;
        }
 
-       if (!ctl->run_once && ctl->old_rows != ctl->rows) {
-               resizeterm(ctl->rows, ctl->cols);
-               ctl->old_rows = ctl->rows;
-       }
        if (init_scols_table(ctl))
                return 1;
 
@@ -556,6 +551,7 @@ static int event_loop(struct irqtop_ctl *const ctl)
                err(EXIT_FAILURE, _("cannot not create timerfd"));
        if (timerfd_settime(tfd, 0, &ctl->timer, NULL) != 0)
                err(EXIT_FAILURE, _("cannot set timerfd"));
+
        ev.events = EPOLLIN;
        ev.data.fd = tfd;
        if (epoll_ctl(efd, EPOLL_CTL_ADD, tfd, &ev) != 0)
@@ -565,8 +561,15 @@ static int event_loop(struct irqtop_ctl *const ctl)
                err(EXIT_FAILURE, _("sigfillset failed"));
        if (sigprocmask(SIG_BLOCK, &sigmask, NULL) != 0)
                err(EXIT_FAILURE, _("sigprocmask failed"));
-       if ((sfd = signalfd(-1, &sigmask, 0)) < 0)
+
+       sigaddset(&sigmask, SIGWINCH);
+       sigaddset(&sigmask, SIGTERM);
+       sigaddset(&sigmask, SIGINT);
+       sigaddset(&sigmask, SIGQUIT);
+
+       if ((sfd = signalfd(-1, &sigmask, SFD_CLOEXEC)) < 0)
                err(EXIT_FAILURE, _("cannot not create signalfd"));
+
        ev.events = EPOLLIN;
        ev.data.fd = sfd;
        if (epoll_ctl(efd, EPOLL_CTL_ADD, sfd, &ev) != 0)
@@ -592,8 +595,10 @@ static int event_loop(struct irqtop_ctl *const ctl)
                                        warn(_("read failed"));
                                        continue;
                                }
-                               if (siginfo.ssi_signo == SIGWINCH)
+                               if (siginfo.ssi_signo == SIGWINCH) {
                                        get_terminal_dimension(&ctl->cols, &ctl->rows);
+                                       resizeterm(ctl->rows, ctl->cols);
+                               }
                                else {
                                        ctl->request_exit = 1;
                                        break;
@@ -682,7 +687,7 @@ static void parse_args(struct irqtop_ctl *const ctl, int const argc,
 
 int main(int argc, char **argv)
 {
-       int is_tty;
+       int is_tty = 0;
        int retval = EXIT_SUCCESS;
        struct termios saved_tty;
        struct irqtop_ctl ctl = {
@@ -703,18 +708,17 @@ int main(int argc, char **argv)
                ctl.columns[ctl.ncolumns++] = COL_NAME;
        }
 
-       is_tty = isatty(STDIN_FILENO);
-       if (is_tty && tcgetattr(STDIN_FILENO, &saved_tty) == -1)
-               fputs(_("terminal setting retrieval"), stdout);
-
-       ctl.old_rows = ctl.rows;
-       get_terminal_dimension(&ctl.cols, &ctl.rows);
        if (!ctl.run_once) {
+               is_tty = isatty(STDIN_FILENO);
+               if (is_tty && tcgetattr(STDIN_FILENO, &saved_tty) == -1)
+                       fputs(_("terminal setting retrieval"), stdout);
+
                ctl.win = initscr();
                get_terminal_dimension(&ctl.cols, &ctl.rows);
                resizeterm(ctl.rows, ctl.cols);
                curs_set(0);
        }
+
        ctl.smp_num_cpus = sysconf(_SC_NPROCESSORS_ONLN);
        gettime_monotonic(&ctl.uptime_tv);
        ctl.hostname = xgethostname();
@@ -727,10 +731,9 @@ int main(int argc, char **argv)
        free_irqinfo(ctl.prev_stat);
        free(ctl.hostname);
 
-       if (is_tty)
-               tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_tty);
-
        if (ctl.win) {
+               if (is_tty)
+                       tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_tty);
                delwin(ctl.win);
                endwin();
        }