Patchwork [RFC,v3,1/5] net: introduce glib function for network

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Submitter pingfank@linux.vnet.ibm.com
Date April 8, 2013, 5:36 a.m.
Message ID <1365399368-26967-2-git-send-email-pingfank@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/234579/
State New
Headers show

Comments

pingfank@linux.vnet.ibm.com - April 8, 2013, 5:36 a.m.
Bind each NetClientState with a GSource(ie,NetClientSource). Currently,
these GSource attached with default context, but in future, after
resolving the race between handlers and the interface exposed by
NetClientInfo and other re-entrant issue, we can run NetClientState
on different threads

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 include/net/net.h |   15 +++++++++++++
 net/net.c         |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+), 0 deletions(-)
Stefan Hajnoczi - April 9, 2013, 2:03 p.m.
On Mon, Apr 08, 2013 at 01:36:04PM +0800, Liu Ping Fan wrote:
> Bind each NetClientState with a GSource(ie,NetClientSource). Currently,
> these GSource attached with default context, but in future, after
> resolving the race between handlers and the interface exposed by
> NetClientInfo and other re-entrant issue, we can run NetClientState
> on different threads
> 
> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
> ---
>  include/net/net.h |   15 +++++++++++++
>  net/net.c         |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 76 insertions(+), 0 deletions(-)
> 
> diff --git a/include/net/net.h b/include/net/net.h
> index cb049a1..cb2451d 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -44,6 +44,7 @@ typedef ssize_t (NetReceiveIOV)(NetClientState *, const struct iovec *, int);
>  typedef void (NetCleanup) (NetClientState *);
>  typedef void (LinkStatusChanged)(NetClientState *);
>  typedef void (NetClientDestructor)(NetClientState *);
> +typedef void (NetClientBindCtx)(NetClientState *, GMainContext *);
>  
>  typedef struct NetClientInfo {
>      NetClientOptionsKind type;
> @@ -55,8 +56,20 @@ typedef struct NetClientInfo {
>      NetCleanup *cleanup;
>      LinkStatusChanged *link_status_changed;
>      NetPoll *poll;
> +    NetClientBindCtx *bind_ctx;
>  } NetClientInfo;
>  
> +typedef bool (*Pollable)(void *opaque);
> +
> +typedef struct NetClientSource {
> +    GSource source;
> +    /* fix me, to expand as array in future */
> +    GPollFD gfd;
> +    Pollable readable;
> +    Pollable writable;
> +    void *opaque;
> +} NetClientSource;

This struct has nothing to do with the net subsystem.  It is a generic
utility for file descriptor read/write monitoring.  It should be in a
separate file (maybe util/fdsource.c?).

NetClient should not know about the GSource at all.  It's an
implementation detail of the NetClient, just like the actual fd is also
an implementation detail that net.h/net.c doesn't know about.

Stefan

Patch

diff --git a/include/net/net.h b/include/net/net.h
index cb049a1..cb2451d 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -44,6 +44,7 @@  typedef ssize_t (NetReceiveIOV)(NetClientState *, const struct iovec *, int);
 typedef void (NetCleanup) (NetClientState *);
 typedef void (LinkStatusChanged)(NetClientState *);
 typedef void (NetClientDestructor)(NetClientState *);
+typedef void (NetClientBindCtx)(NetClientState *, GMainContext *);
 
 typedef struct NetClientInfo {
     NetClientOptionsKind type;
@@ -55,8 +56,20 @@  typedef struct NetClientInfo {
     NetCleanup *cleanup;
     LinkStatusChanged *link_status_changed;
     NetPoll *poll;
+    NetClientBindCtx *bind_ctx;
 } NetClientInfo;
 
+typedef bool (*Pollable)(void *opaque);
+
+typedef struct NetClientSource {
+    GSource source;
+    /* fix me, to expand as array in future */
+    GPollFD gfd;
+    Pollable readable;
+    Pollable writable;
+    void *opaque;
+} NetClientSource;
+
 struct NetClientState {
     NetClientInfo *info;
     int link_down;
@@ -69,6 +82,7 @@  struct NetClientState {
     unsigned receive_disabled : 1;
     NetClientDestructor *destructor;
     unsigned int queue_index;
+    NetClientSource *nsrc;
 };
 
 typedef struct NICState {
@@ -155,6 +169,7 @@  extern int default_net;
 extern const char *legacy_tftp_prefix;
 extern const char *legacy_bootp_filename;
 
+NetClientSource *net_source_new(int fd, GSourceFunc f, void *opaque);
 int net_client_init(QemuOpts *opts, int is_netdev, Error **errp);
 int net_client_parse(QemuOptsList *opts_list, const char *str);
 int net_init_clients(void);
diff --git a/net/net.c b/net/net.c
index f3d67f8..6aecf93 100644
--- a/net/net.c
+++ b/net/net.c
@@ -299,6 +299,9 @@  static void qemu_free_net_client(NetClientState *nc)
     }
     g_free(nc->name);
     g_free(nc->model);
+    if (nc->nsrc) {
+        g_source_remove(g_source_get_id(&nc->nsrc->source));
+    }
     if (nc->destructor) {
         nc->destructor(nc);
     }
@@ -558,6 +561,64 @@  qemu_sendv_packet(NetClientState *nc, const struct iovec *iov, int iovcnt)
     return qemu_sendv_packet_async(nc, iov, iovcnt, NULL);
 }
 
+static gboolean prepare(GSource *src, gint *time)
+{
+    NetClientSource *nsrc = (NetClientSource *)src;
+    int events = 0;
+
+    if (!nsrc->readable && !nsrc->writable) {
+        return false;
+    }
+    if (nsrc->readable && nsrc->readable(nsrc->opaque)) {
+        events |= G_IO_IN;
+    }
+    if ((nsrc->writable) && nsrc->writable(nsrc->opaque)) {
+        events |= G_IO_OUT;
+    }
+    nsrc->gfd.events = events;
+
+    return false;
+}
+
+static gboolean check(GSource *src)
+{
+    NetClientSource *nsrc = (NetClientSource *)src;
+
+    if (nsrc->gfd.revents & nsrc->gfd.events) {
+        return true;
+    }
+    return false;
+}
+
+static gboolean dispatch(GSource *src, GSourceFunc cb, gpointer data)
+{
+    gboolean ret = false;
+
+    if (cb) {
+        ret = cb(data);
+    }
+    return ret;
+}
+
+static GSourceFuncs net_gsource_funcs = {
+    prepare,
+    check,
+    dispatch,
+    NULL
+};
+
+NetClientSource *net_source_new(int fd, GSourceFunc f, void *opaque)
+{
+    NetClientSource *nsrc = (NetClientSource *)g_source_new(&net_gsource_funcs,
+                                                    sizeof(NetClientSource));
+    nsrc->gfd.fd = fd;
+    nsrc->opaque = opaque;
+    g_source_set_callback(&nsrc->source, f, nsrc, NULL);
+    g_source_add_poll(&nsrc->source, &nsrc->gfd);
+
+    return nsrc;
+}
+
 NetClientState *qemu_find_netdev(const char *id)
 {
     NetClientState *nc;