[Qemu-devel] [PATCH v3 3/3] chardev: introduce qemu_chr_timeout_add_ms()

[Peter Xu <peterx@redhat.com>]

It's a replacement of g_timeout_add[_seconds]() for chardevs.  Chardevs
now can have dedicated gcontext, we should always bind chardev tasks
onto those gcontext rather than the default main context.  Since there
are quite a few of g_timeout_add[_seconds]() callers, a new function
qemu_chr_timeout_add_ms() is introduced.

One thing to mention is that, terminal3270 is still always running on
main gcontext.  However let's convert that as well since it's still part
of chardev codes and in case one day we'll miss that when we move it out
of main gcontext too.

Also, in pty_chr_rearm_timer() the GSource name is not user visible, and
does not really matter much.  Unify the two calls into one.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 chardev/char-pty.c     |  9 ++-------
 chardev/char-socket.c  |  6 ++++--
 chardev/char.c         | 21 +++++++++++++++++++++
 hw/char/terminal3270.c |  7 ++++---
 include/chardev/char.h |  3 +++
 5 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/chardev/char-pty.c b/chardev/char-pty.c
index dd17b1b823..2b37ad55ed 100644
--- a/chardev/char-pty.c
+++ b/chardev/char-pty.c
@@ -78,13 +78,8 @@ static void pty_chr_rearm_timer(Chardev *chr, int ms)
         s->timer_tag = 0;
     }
 
-    if (ms == 1000) {
-        name = g_strdup_printf("pty-timer-secs-%s", chr->label);
-        s->timer_tag = g_timeout_add_seconds(1, pty_chr_timer, chr);
-    } else {
-        name = g_strdup_printf("pty-timer-ms-%s", chr->label);
-        s->timer_tag = g_timeout_add(ms, pty_chr_timer, chr);
-    }
+    name = g_strdup_printf("pty-timer-ms-%s", chr->label);
+    s->timer_tag = qemu_chr_timeout_add_ms(chr, ms, pty_chr_timer, chr);
     g_source_set_name_by_id(s->timer_tag, name);
     g_free(name);
 }
diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index 630a7f2995..9527314708 100644
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -73,8 +73,10 @@ static void qemu_chr_socket_restart_timer(Chardev *chr)
     char *name;
 
     assert(s->connected == 0);
-    s->reconnect_timer = g_timeout_add_seconds(s->reconnect_time,
-                                               socket_reconnect_timeout, chr);
+    s->reconnect_timer = qemu_chr_timeout_add_ms(chr,
+                                                 s->reconnect_time * 1000,
+                                                 socket_reconnect_timeout,
+                                                 chr);
     name = g_strdup_printf("chardev-socket-reconnect-%s", chr->label);
     g_source_set_name_by_id(s->reconnect_timer, name);
     g_free(name);
diff --git a/chardev/char.c b/chardev/char.c
index 8c3765ee99..d77787d67a 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -1084,6 +1084,27 @@ void qmp_chardev_send_break(const char *id, Error **errp)
     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
 }
 
+/*
+ * Add a timeout callback for the chardev (in milliseconds). Please
+ * use this to add timeout hook for chardev instead of g_timeout_add()
+ * and g_timeout_add_seconds(), to make sure the gcontext that the
+ * task bound to is correct.  Returns the ID of the timeout GSource in
+ * gcontext of the chardev.
+ */
+guint qemu_chr_timeout_add_ms(Chardev *chr, guint ms, GSourceFunc func,
+                              void *private)
+{
+    GSource *source = g_timeout_source_new(ms);
+    guint id;
+
+    assert(func);
+    g_source_set_callback(source, func, private, NULL);
+    id = g_source_attach(source, chr->gcontext);
+    g_source_unref(source);
+
+    return id;
+}
+
 void qemu_chr_cleanup(void)
 {
     object_unparent(get_chardevs_root());
diff --git a/hw/char/terminal3270.c b/hw/char/terminal3270.c
index a109ce5987..b0f81d0d16 100644
--- a/hw/char/terminal3270.c
+++ b/hw/char/terminal3270.c
@@ -94,8 +94,8 @@ static void terminal_read(void *opaque, const uint8_t *buf, int size)
         g_source_remove(t->timer_tag);
         t->timer_tag = 0;
     }
-    t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
-
+    t->timer_tag = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
+                                           send_timing_mark_cb, t);
     memcpy(&t->inv[t->in_len], buf, size);
     t->in_len += size;
     if (t->in_len < 2) {
@@ -157,7 +157,8 @@ static void chr_event(void *opaque, int event)
          * char-socket.c. Once qemu receives the terminal-type of the
          * client, mark handshake done and trigger everything rolling again.
          */
-        t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
+        t->timer_tag = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
+                                               send_timing_mark_cb, t);
         break;
     case CHR_EVENT_CLOSED:
         sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
diff --git a/include/chardev/char.h b/include/chardev/char.h
index 778d610295..f1b67af4d2 100644
--- a/include/chardev/char.h
+++ b/include/chardev/char.h
@@ -256,6 +256,9 @@ Chardev *qemu_chardev_new(const char *id, const char *typename,
 
 extern int term_escape_char;
 
+guint qemu_chr_timeout_add_ms(Chardev *chr, guint ms, GSourceFunc func,
+                              void *private);
+
 /* console.c */
 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 
-- 
2.14.3