Commit 4d88a2ac authored by Anthony Liguori's avatar Anthony Liguori
Browse files

main: switch qemu_set_fd_handler to g_io_add_watch 



This patch changes qemu_set_fd_handler to be implemented in terms of
g_io_add_watch().  The semantics are a bit different so some glue is required.

qemu_set_fd_handler2 is much harder to convert because of its use of polling.

The glib main loop has the major of advantage of having a proven thread safe
architecture.  By using the glib main loop instead of our own, it will allow us
to eventually introduce multiple I/O threads.

I'm pretty sure that this will work on Win32, but I would appreciate some help
testing.  I think the semantics of g_io_channel_unix_new() are really just tied
to the notion of a "unix fd" and not necessarily unix itself.

Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent 69e5bb68

iohandler.c

+56 −1
Original line number Diff line number Diff line
@@ -80,12 +80,67 @@ int qemu_set_fd_handler2(int fd, 
    return 0;

}



typedef struct IOTrampoline

{

    GIOChannel *chan;

    IOHandler *fd_read;

    IOHandler *fd_write;

    void *opaque;

    guint tag;

} IOTrampoline;



static gboolean fd_trampoline(GIOChannel *chan, GIOCondition cond, gpointer opaque)

{

    IOTrampoline *tramp = opaque;



    if (tramp->opaque == NULL) {

        return FALSE;

    }



    if ((cond & G_IO_IN) && tramp->fd_read) {

        tramp->fd_read(tramp->opaque);

    }



    if ((cond & G_IO_OUT) && tramp->fd_write) {

        tramp->fd_write(tramp->opaque);

    }



    return TRUE;

}



int qemu_set_fd_handler(int fd,

                        IOHandler *fd_read,

                        IOHandler *fd_write,

                        void *opaque)

{

    return qemu_set_fd_handler2(fd, NULL, fd_read, fd_write, opaque);

    static IOTrampoline fd_trampolines[FD_SETSIZE];

    IOTrampoline *tramp = &fd_trampolines[fd];



    if (tramp->tag != 0) {

        g_io_channel_unref(tramp->chan);

        g_source_remove(tramp->tag);

    }



    if (opaque) {

        GIOCondition cond = 0;



        tramp->fd_read = fd_read;

        tramp->fd_write = fd_write;

        tramp->opaque = opaque;



        if (fd_read) {

            cond |= G_IO_IN | G_IO_ERR;

        }



        if (fd_write) {

            cond |= G_IO_OUT | G_IO_ERR;

        }



        tramp->chan = g_io_channel_unix_new(fd);

        tramp->tag = g_io_add_watch(tramp->chan, cond, fd_trampoline, tramp);

    }



    return 0;

}



void qemu_iohandler_fill(int *pnfds, fd_set *readfds, fd_set *writefds, fd_set *xfds)