Re: [PATCH 18/28] libxl: ocaml: add xen_console_read

[David Scott <dave.scott@eu.citrix.com>]

On 25/03/13 14:45, Rob Hoes wrote:
> Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
> ---
>   tools/ocaml/libs/xl/xenlight.ml.in   |    1 +
>   tools/ocaml/libs/xl/xenlight.mli.in  |    1 +
>   tools/ocaml/libs/xl/xenlight_stubs.c |   27 +++++++++++++++++++++++++++
>   3 files changed, 29 insertions(+)
>
> diff --git a/tools/ocaml/libs/xl/xenlight.ml.in b/tools/ocaml/libs/xl/xenlight.ml.in
> index 991b2bf..63b8bf8 100644
> --- a/tools/ocaml/libs/xl/xenlight.ml.in
> +++ b/tools/ocaml/libs/xl/xenlight.ml.in
> @@ -78,5 +78,6 @@ type devid = int
>   external send_trigger : ctx -> domid -> trigger -> int -> unit = "stub_xl_send_trigger"
>   external send_sysrq : ctx -> domid -> char -> unit = "stub_xl_send_sysrq"
>   external send_debug_keys : ctx -> string -> unit = "stub_xl_send_debug_keys"
> +external xen_console_read : ctx -> string list = "stub_xl_xen_console_read"
>
>   let _ = Callback.register_exception "Xenlight.Error" (Error(Fail, ""))
> diff --git a/tools/ocaml/libs/xl/xenlight.mli.in b/tools/ocaml/libs/xl/xenlight.mli.in
> index 12568ca..24064fc 100644
> --- a/tools/ocaml/libs/xl/xenlight.mli.in
> +++ b/tools/ocaml/libs/xl/xenlight.mli.in
> @@ -50,3 +50,4 @@ type devid = int
>   external send_trigger : ctx -> domid -> trigger -> int -> unit = "stub_xl_send_trigger"
>   external send_sysrq : ctx -> domid -> char -> unit = "stub_xl_send_sysrq"
>   external send_debug_keys : ctx -> string -> unit = "stub_xl_send_debug_keys"
> +external xen_console_read : ctx -> string list = "stub_xl_xen_console_read"
> diff --git a/tools/ocaml/libs/xl/xenlight_stubs.c b/tools/ocaml/libs/xl/xenlight_stubs.c
> index f4fa520..939e993 100644
> --- a/tools/ocaml/libs/xl/xenlight_stubs.c
> +++ b/tools/ocaml/libs/xl/xenlight_stubs.c
> @@ -484,6 +484,33 @@ value stub_xl_send_debug_keys(value ctx, value keys)
>   	CAMLreturn(Val_unit);
>   }
>
> +value stub_xl_xen_console_read(value ctx)
> +{
> +	CAMLparam1(ctx);
> +	CAMLlocal3(list, cons, ml_line);
> +	int i = 0, ret;
> +	char *console[32768], *line;
> +	libxl_xen_console_reader *cr;
> +
> +	cr = libxl_xen_console_read_start(CTX, 0);
> +	if (cr)
> +		for (i = 0; libxl_xen_console_read_line(CTX, cr, &line) > 0; i++)
 > +			console[i] = strdup(line);

Is it obvious why i is always < 32768? Or is 32768 "too big to fail"? 
(Sorry, couldn't resist)

> +	libxl_xen_console_read_finish(CTX, cr);
> +
> +	list = Val_emptylist;
> +	for (; i > 0; i--) {
> +		ml_line = caml_copy_string(console[i - 1]);
> +		free(console[i - 1]);
> +		cons = caml_alloc(2, 0);
> +		Store_field(cons, 0, ml_line);  // head
> +		Store_field(cons, 1, list);     // tail
> +		list = cons;
> +	}
> +
> +	CAMLreturn(list);
> +}
> +
>   /*
>    * Local variables:
>    *  indent-tabs-mode: t
>