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: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2011-08-22 08:12:53 -05:00
parent 69e5bb68a5
commit 4d88a2ac86

View File

@ -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)