Attachment 37970 Details for Bug 17720 – New patch that uses new VT_WAITEVENT ioctl

[patch] New patch that uses new VT_WAITEVENT ioctl

0001-Use-VT_WAITEVENT-if-available-to-avoid-spawn-too-man.patch (text/plain), 4.98 KB, created by Kan-Ru Chen on 2010-08-19 02:38:15 UTC

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Creator: Kan-Ru Chen

Created: 2010-08-19 02:38:15 UTC

Size: 4.98 KB

patch

obsolete

>From bd4ea39dec291dba9e8b6ad845e80cd534a21eaf Mon Sep 17 00:00:00 2001
>From: Kan-Ru Chen <koster@debian.org>
>Date: Thu, 19 Aug 2010 13:45:03 +0800
>Subject: [PATCH] Use VT_WAITEVENT if available to avoid spawn too many threads
>
>Starting from linux kernel 2.6.32 there is a new ioctl VT_WAITEVENT
>which can monitor vt switches and return new vt number.
>
>https://bugs.freedesktop.org/show_bug.cgi?id=17720
>---
> Please CC me on any replies (non-subscriber)
>
> src/ck-sysdeps-unix.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
> src/ck-sysdeps.h      |    2 ++
> src/ck-vt-monitor.c   |   32 ++++++++++++++++++++++++++++++--
> 3 files changed, 76 insertions(+), 2 deletions(-)
>
>diff --git a/src/ck-sysdeps-unix.c b/src/ck-sysdeps-unix.c
>index e4ab16b..90c514d 100644
>--- a/src/ck-sysdeps-unix.c
>+++ b/src/ck-sysdeps-unix.c
>@@ -296,6 +296,50 @@ ck_wait_for_active_console_num (int   console_fd,
>         return ret;
> }
> 
>+#ifdef VT_WAITEVENT
>+gboolean
>+ck_wait_for_console_switch (int   console_fd,
>+                            guint *num)
>+{
>+        gboolean ret;
>+        int      res;
>+        struct vt_event vt;
>+
>+        g_assert (console_fd != -1);
>+
>+ again:
>+        ret = FALSE;
>+        errno = 0;
>+        vt.event = VT_EVENT_SWITCH;
>+        vt.oldev = num;
>+        res = ioctl (console_fd, VT_WAITEVENT, &vt);
>+
>+        if (res == ERROR) {
>+                const char *errmsg;
>+
>+                errmsg = g_strerror (errno);
>+
>+                if (errno == EINTR) {
>+                        g_debug ("Interrupted waiting for native console event: %s",
>+                                  errmsg);
>+                       goto again;
>+                } else if (errno == ENOTSUP) {
>+                        g_debug ("Console event not supported on this system");
>+                } else {
>+                        g_warning ("Error waiting for native console event: %s",
>+                                   errmsg);
>+                }
>+                goto out;
>+        }
>+
>+        ret = TRUE;
>+        *num = vt.newev;
>+
>+ out:
>+        return ret;
>+}
>+#endif
>+
> gboolean
> ck_activate_console_num (int   console_fd,
>                          guint num)
>diff --git a/src/ck-sysdeps.h b/src/ck-sysdeps.h
>index 8f22d52..5dd573f 100644
>--- a/src/ck-sysdeps.h
>+++ b/src/ck-sysdeps.h
>@@ -72,6 +72,8 @@ gboolean     ck_activate_console_num          (int             console_fd,
>                                                guint           num);
> gboolean     ck_wait_for_active_console_num   (int             console_fd,
>                                                guint           num);
>+gboolean     ck_wait_for_console_switch       (int             console_fd,
>+                                               guint          *num);
> 
> G_END_DECLS
> 
>diff --git a/src/ck-vt-monitor.c b/src/ck-vt-monitor.c
>index 67a1f49..414bdbb 100644
>--- a/src/ck-vt-monitor.c
>+++ b/src/ck-vt-monitor.c
>@@ -40,7 +40,7 @@
> #include "ck-sysdeps.h"
> #include "ck-marshal.h"
> 
>-#if defined (__sun) && defined (HAVE_SYS_VT_H)
>+#ifdef HAVE_SYS_VT_H
> #include <sys/vt.h>
> #include <signal.h>
> #include <stropts.h>
>@@ -163,7 +163,7 @@ ck_vt_monitor_get_active (CkVtMonitor    *vt_monitor,
>         return TRUE;
> }
> 
>-#if defined (__sun) && defined (HAVE_SYS_VT_H)
>+#ifdef HAVE_SYS_VT_H
> static void
> handle_vt_active (void)
> {
>@@ -318,6 +318,26 @@ vt_thread_start (ThreadData *data)
>         vt_monitor = data->vt_monitor;
>         num = data->num;
> 
>+#ifdef VT_WAITEVENT
>+        for (;;) {
>+                res = ck_wait_for_console_switch (vt_monitor->priv->vfd, &num);
>+                if (! res) {
>+                        break;
>+                } else {
>+                        EventData *event;
>+
>+                        /* add event to queue */
>+                        event = g_new0 (EventData, 1);
>+                        event->num = num;
>+                        g_debug ("Pushing activation event for VT %d onto queue", num);
>+
>+                        g_async_queue_push (vt_monitor->priv->event_queue, event);
>+
>+                        /* schedule processing of queue */
>+                        schedule_process_queue (vt_monitor);
>+                }
>+        }
>+#else
>         res = ck_wait_for_active_console_num (vt_monitor->priv->vfd, num);
>         if (! res) {
>                 /* FIXME: what do we do if it fails? */
>@@ -334,6 +354,7 @@ vt_thread_start (ThreadData *data)
>                 /* schedule processing of queue */
>                 schedule_process_queue (vt_monitor);
>         }
>+#endif
> 
>         G_LOCK (hash_lock);
>         if (vt_monitor->priv->vt_thread_hash != NULL) {
>@@ -398,6 +419,13 @@ vt_add_watches (CkVtMonitor *vt_monitor)
>         sigaction (SIGPOLL, &act, NULL);
> 
>         ioctl (vt_monitor->priv->vfd, I_SETSIG, S_MSG);
>+#elif defined (VT_WAITEVENT)
>+        G_LOCK (hash_lock);
>+        gpointer id;
>+        id = GINT_TO_POINTER (1);
>+        if (g_hash_table_lookup (vt_monitor->priv->vt_thread_hash, id) == NULL)
>+                vt_add_watch_unlocked (vt_monitor, 1);
>+        G_UNLOCK (hash_lock);
> #else
>         G_LOCK (hash_lock);
> 
>-- 
>1.7.1
>

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