can tell when a window that was "closed" has stopped responding now

1 files changed, 151 insertions, 0 deletions

diff --git a/openbox/ping.c b/openbox/ping.c
new file mode 100644
index 00000000..d8c10c83
--- /dev/null
+++ b/openbox/ping.c
@@ -0,0 +1,151 @@
+/* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-
+
+   client.h for the Openbox window manager
+   Copyright (c) 2006        Mikael Magnusson
+   Copyright (c) 2003-2008   Dana Jansens
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   See the COPYING file for a copy of the GNU General Public License.
+*/
+
+#include "ping.h"
+#include "client.h"
+#include "prop.h"
+#include "event.h"
+#include "mainloop.h"
+#include "openbox.h"
+
+typedef struct _ObPingTarget
+{
+    ObClient *client;
+    ObPingEventHandler h;
+    Time sent;
+    gint waiting;
+} ObPingTarget;
+
+static GSList *ping_targets = NULL;
+static gboolean active = FALSE;
+
+#define PING_TIMEOUT (G_USEC_PER_SEC * 1)
+/*! Warn the user after this many PING_TIMEOUT intervals */
+#define PING_TIMEOUT_WARN 3
+
+static void ping_send(ObPingTarget *t);
+static void ping_end(ObClient *client, gpointer data);
+static gboolean ping_timeout(gpointer data);
+
+void ping_start(struct _ObClient *client, ObPingEventHandler h)
+{
+    GSList *it;
+    ObPingTarget *t;
+
+    /* make sure we're not already pinging it */
+    for (it = ping_targets; it != NULL; it = g_slist_next(it)) {
+        t = it->data;
+        if (t->client == client) return;
+    }
+
+    t = g_new(ObPingTarget, 1);
+    t->client = client;
+    t->h = h;
+    t->waiting = 1; /* first wait for a reply */
+
+    ping_send(t);
+    ping_targets = g_slist_prepend(ping_targets, t);
+    ob_main_loop_timeout_add(ob_main_loop, PING_TIMEOUT, ping_timeout,
+                             t, NULL, NULL);
+
+    if (!active) {
+        active = TRUE;
+        /* listen for the client to disappear */
+        client_add_destroy_notify(ping_end, NULL);
+    }
+}
+
+void ping_stop(struct _ObClient *c)
+{
+    ping_end(c, NULL);
+}
+
+void ping_got_pong(Time timestamp)
+{
+    GSList *it;
+    ObPingTarget *t;
+
+    /* make sure we're not already pinging it */
+    for (it = ping_targets; it != NULL; it = g_slist_next(it)) {
+        t = it->data;
+        if (t->sent == timestamp) {
+            ob_debug("Got PONG with timestamp %lu\n", timestamp);
+            if (t->waiting > PING_TIMEOUT_WARN) {
+                /* we had notified that they weren't responding, so now we
+                   need to notify that they are again */
+                t->h(t->client, FALSE);
+            }
+            t->waiting = 0; /* not waiting for a reply anymore */
+            break;
+        }
+    }
+
+    if (it == NULL)
+        ob_debug("Got PONG with timestamp %lu but not waiting for one\n",
+                 timestamp);
+}
+
+static void ping_send(ObPingTarget *t)
+{
+    t->sent = event_get_server_time();
+    ob_debug("PINGing client 0x%x at %lu\n", t->client->window, t->sent);
+    PROP_MSG_TO(t->client->window, t->client->window, wm_protocols,
+                prop_atoms.net_wm_ping, t->sent, t->client->window, 0, 0,
+                NoEventMask);
+}
+
+static gboolean ping_timeout(gpointer data)
+{
+    ObPingTarget *t = data;
+
+    if (t->waiting == 0) { /* got a reply already */
+        /* send another ping to make sure it's still alive */
+        ping_send(t);
+    }
+
+    if (t->waiting == PING_TIMEOUT_WARN)
+        t->h(t->client, TRUE); /* notify that the client isn't responding */
+
+    ++t->waiting;
+
+    return TRUE; /* repeat */
+}
+
+static void ping_end(ObClient *client, gpointer data)
+{
+    GSList *it;
+    ObPingTarget *t;
+
+    for (it = ping_targets; it != NULL; it = g_slist_next(it)) {
+        t = it->data;
+        if (t->client == client) {
+            ping_targets = g_slist_remove_link(ping_targets, it);
+            ob_main_loop_timeout_remove_data(ob_main_loop, ping_timeout, t,
+                                             FALSE);
+            g_free(t);
+            break;
+        }
+    }
+
+    /* stop listening if we're not waiting for any more pings */
+    if (!ping_targets) {
+        active = TRUE;
+        client_remove_destroy_notify(ping_end);
+    }    
+}