[PATCH 7/8] chardev/mux: implement detach of frontends from mux

Roman Penyaev posted 8 patches 1 month, 1 week ago
There is a newer version of this series
[PATCH 7/8] chardev/mux: implement detach of frontends from mux
Posted by Roman Penyaev 1 month, 1 week ago
With bitset management now it becomes feasible to implement
the logic of detaching frontends from multiplexer.

Signed-off-by: Roman Penyaev <r.peniaev@gmail.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: qemu-devel@nongnu.org
---
 chardev/char-fe.c          |  2 +-
 chardev/char-mux.c         | 20 +++++++++++++++++---
 chardev/chardev-internal.h |  1 +
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/chardev/char-fe.c b/chardev/char-fe.c
index 3b8771ca2ac4..8ac6bebb6f74 100644
--- a/chardev/char-fe.c
+++ b/chardev/char-fe.c
@@ -225,7 +225,7 @@ void qemu_chr_fe_deinit(CharBackend *b, bool del)
         }
         if (CHARDEV_IS_MUX(b->chr)) {
             MuxChardev *d = MUX_CHARDEV(b->chr);
-            d->backends[b->tag] = NULL;
+            mux_chr_detach_frontend(d, b->tag);
         }
         if (del) {
             Object *obj = OBJECT(b->chr);
diff --git a/chardev/char-mux.c b/chardev/char-mux.c
index 9c3cacb2fecd..649f8ff6ccbf 100644
--- a/chardev/char-mux.c
+++ b/chardev/char-mux.c
@@ -289,10 +289,10 @@ static void char_mux_finalize(Object *obj)
     bit = -1;
     while ((bit = find_next_bit(&d->mux_bitset, MAX_MUX, bit + 1)) < MAX_MUX) {
         CharBackend *be = d->backends[bit];
-        if (be) {
-            be->chr = NULL;
-        }
+        be->chr = NULL;
+        d->backends[bit] = NULL;
     }
+    d->mux_bitset = 0;
     qemu_chr_fe_deinit(&d->chr, false);
 }
 
@@ -331,6 +331,21 @@ bool mux_chr_attach_frontend(MuxChardev *d, CharBackend *b,
     return true;
 }
 
+bool mux_chr_detach_frontend(MuxChardev *d, unsigned int tag)
+{
+    unsigned int bit;
+
+    bit = find_next_bit(&d->mux_bitset, MAX_MUX, tag);
+    if (bit >= MAX_MUX) {
+        return false;
+    }
+
+    d->mux_bitset &= ~(1 << bit);
+    d->backends[bit] = NULL;
+
+    return true;
+}
+
 void mux_set_focus(Chardev *chr, unsigned int focus)
 {
     MuxChardev *d = MUX_CHARDEV(chr);
diff --git a/chardev/chardev-internal.h b/chardev/chardev-internal.h
index b89aada5413b..853807f3cb88 100644
--- a/chardev/chardev-internal.h
+++ b/chardev/chardev-internal.h
@@ -61,6 +61,7 @@ DECLARE_INSTANCE_CHECKER(MuxChardev, MUX_CHARDEV,
 
 bool mux_chr_attach_frontend(MuxChardev *d, CharBackend *b,
                              unsigned int *tag, Error **errp);
+bool mux_chr_detach_frontend(MuxChardev *d, unsigned int tag);
 void mux_set_focus(Chardev *chr, unsigned int focus);
 void mux_chr_send_all_event(Chardev *chr, QEMUChrEvent event);
 
-- 
2.34.1


Re: [PATCH 7/8] chardev/mux: implement detach of frontends from mux
Posted by Marc-André Lureau 1 month, 1 week ago
Hi

On Mon, Oct 14, 2024 at 3:46 PM Roman Penyaev <r.peniaev@gmail.com> wrote:

> With bitset management now it becomes feasible to implement
> the logic of detaching frontends from multiplexer.
>
> Signed-off-by: Roman Penyaev <r.peniaev@gmail.com>
> Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
> Cc: qemu-devel@nongnu.org
> ---
>  chardev/char-fe.c          |  2 +-
>  chardev/char-mux.c         | 20 +++++++++++++++++---
>  chardev/chardev-internal.h |  1 +
>  3 files changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/chardev/char-fe.c b/chardev/char-fe.c
> index 3b8771ca2ac4..8ac6bebb6f74 100644
> --- a/chardev/char-fe.c
> +++ b/chardev/char-fe.c
> @@ -225,7 +225,7 @@ void qemu_chr_fe_deinit(CharBackend *b, bool del)
>          }
>          if (CHARDEV_IS_MUX(b->chr)) {
>              MuxChardev *d = MUX_CHARDEV(b->chr);
> -            d->backends[b->tag] = NULL;
> +            mux_chr_detach_frontend(d, b->tag);
>
         }
>          if (del) {
>              Object *obj = OBJECT(b->chr);
> diff --git a/chardev/char-mux.c b/chardev/char-mux.c
> index 9c3cacb2fecd..649f8ff6ccbf 100644
> --- a/chardev/char-mux.c
> +++ b/chardev/char-mux.c
> @@ -289,10 +289,10 @@ static void char_mux_finalize(Object *obj)
>      bit = -1;
>      while ((bit = find_next_bit(&d->mux_bitset, MAX_MUX, bit + 1)) <
> MAX_MUX) {
>          CharBackend *be = d->backends[bit];
> -        if (be) {
> -            be->chr = NULL;
> -        }
> +        be->chr = NULL;
> +        d->backends[bit] = NULL;
>      }
> +    d->mux_bitset = 0;
>      qemu_chr_fe_deinit(&d->chr, false);
>  }
>
> @@ -331,6 +331,21 @@ bool mux_chr_attach_frontend(MuxChardev *d,
> CharBackend *b,
>      return true;
>  }
>
> +bool mux_chr_detach_frontend(MuxChardev *d, unsigned int tag)
> +{
> +    unsigned int bit;
> +
> +    bit = find_next_bit(&d->mux_bitset, MAX_MUX, tag);
> +    if (bit >= MAX_MUX) {
>

if (bit != tag) instead?


> +        return false;
> +    }
> +
> +    d->mux_bitset &= ~(1 << bit);
> +    d->backends[bit] = NULL;
> +
> +    return true;
> +}
> +
>  void mux_set_focus(Chardev *chr, unsigned int focus)
>  {
>      MuxChardev *d = MUX_CHARDEV(chr);
> diff --git a/chardev/chardev-internal.h b/chardev/chardev-internal.h
> index b89aada5413b..853807f3cb88 100644
> --- a/chardev/chardev-internal.h
> +++ b/chardev/chardev-internal.h
> @@ -61,6 +61,7 @@ DECLARE_INSTANCE_CHECKER(MuxChardev, MUX_CHARDEV,
>
>  bool mux_chr_attach_frontend(MuxChardev *d, CharBackend *b,
>                               unsigned int *tag, Error **errp);
> +bool mux_chr_detach_frontend(MuxChardev *d, unsigned int tag);
>  void mux_set_focus(Chardev *chr, unsigned int focus);
>  void mux_chr_send_all_event(Chardev *chr, QEMUChrEvent event);
>
> --
> 2.34.1
>
>
>

-- 
Marc-André Lureau
Re: [PATCH 7/8] chardev/mux: implement detach of frontends from mux
Posted by Roman Penyaev 1 month, 1 week ago
On Mon, Oct 14, 2024 at 3:22 PM Marc-André Lureau
<marcandre.lureau@gmail.com> wrote:

[cut]

>>
>> +bool mux_chr_detach_frontend(MuxChardev *d, unsigned int tag)
>> +{
>> +    unsigned int bit;
>> +
>> +    bit = find_next_bit(&d->mux_bitset, MAX_MUX, tag);
>> +    if (bit >= MAX_MUX) {
>
>
> if (bit != tag) instead?

Right, thanks.

--
Roman