On Tue, 12/01 21:28, Peter Xu wrote:
> One new QMP event DUMP_COMPLETED is added. When a dump finishes, one
> DUMP_COMPLETED event will occur to notify the user.
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
> ---
> docs/qmp-events.txt | 16 ++++++++++++++++
> dump.c | 11 +++++------
> qapi-schema.json | 3 ++-
> qapi/event.json | 13 +++++++++++++
> qmp-commands.hx | 5 +++--
> util/error.c | 6 +++++-
> 6 files changed, 44 insertions(+), 10 deletions(-)
>
> diff --git a/docs/qmp-events.txt b/docs/qmp-events.txt
> index d2f1ce4..1f79588 100644
> --- a/docs/qmp-events.txt
> +++ b/docs/qmp-events.txt
> @@ -220,6 +220,22 @@ Data:
> },
> "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
>
> +DUMP_COMPLETED
> +--------------
> +
> +Emitted when the guest has finished one memory dump.
> +
> +Data:
> +
> +- "error": Error message when dump failed. This is only a
> + human-readable string provided when dump failed. It should not be
> + parsed in any way (json-string, optional)
> +
> +Example:
> +
> +{ "event": "DUMP_COMPLETED",
> + "data": {} }
> +
> GUEST_PANICKED
> --------------
>
> diff --git a/dump.c b/dump.c
> index c86bc2d..5b040b7 100644
> --- a/dump.c
> +++ b/dump.c
> @@ -25,6 +25,7 @@
> #include "qapi/error.h"
> #include "qapi/qmp/qerror.h"
> #include "qmp-commands.h"
> +#include "qapi-event.h"
>
> #include <zlib.h>
> #ifdef CONFIG_LZO
> @@ -1612,6 +1613,9 @@ static void dump_process(DumpState *s, Error **errp)
> s->status = DUMP_STATUS_COMPLETED;
> }
>
> + /* send DUMP_COMPLETED message (unconditionally) */
> + qapi_event_send_dump_completed(!!(*errp), error_get_pretty(*errp),
> + &error_abort);
> dump_cleanup(s);
> }
>
> @@ -1619,13 +1623,8 @@ static void *dump_thread(void *data)
> {
> Error *err = NULL;
> DumpState *s = (DumpState *)data;
> -
> dump_process(s, &err);
> -
> - if (err) {
> - /* TODO: notify user the error */
> - error_free(err);
> - }
> + error_free(err);
> return NULL;
> }
>
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 691a130..f0d3c4a 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -2116,7 +2116,8 @@
> # is the fd's name.
> #
> # @detach: #optional if true, QMP will return immediately rather than
> -# waiting for the dump to finish. (since 2.6).
> +# waiting for the dump to finish. A DUMP_COMPLETED event will
> +# occur at the end. (since 2.6).
> #
> # @begin: #optional if specified, the starting physical address.
> #
> diff --git a/qapi/event.json b/qapi/event.json
> index f0cef01..9b7f714 100644
> --- a/qapi/event.json
> +++ b/qapi/event.json
> @@ -356,3 +356,16 @@
> ##
> { 'event': 'MEM_UNPLUG_ERROR',
> 'data': { 'device': 'str', 'msg': 'str' } }
> +
> +##
> +# @DUMP_COMPLETED
> +#
> +# Emitted when background dump has completed
> +#
> +# @error: #optional human-readable error string that provides
> +# hint on why dump failed.
Please explicitly mention that successful dump emits DUMP_COMPLETED without
error, and failed dump emits DUMP_COMPLETED that has an error str.
> +#
> +# Since: 2.6
> +##
> +{ 'event': 'DUMP_COMPLETED' ,
> + 'data': { '*error': 'str' } }
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 6b51585..7b6f915 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -857,8 +857,9 @@ Arguments:
> - "paging": do paging to get guest's memory mapping (json-bool)
> - "protocol": destination file(started with "file:") or destination file
> descriptor (started with "fd:") (json-string)
> -- "detach": if specified, command will return immediately, without waiting
> - for the dump to finish (json-bool)
> +- "detach": if specified, command will return immediately rather than waiting
> + for the dump completion. A DUMP_COMPLETED event will occur at
> + the end. (json-bool)
> - "begin": the starting physical address. It's optional, and should be
> specified
> with length together (json-int)
> - "length": the memory size, in bytes. It's optional, and should be specified
> diff --git a/util/error.c b/util/error.c
> index 80c89a2..645b9af 100644
> --- a/util/error.c
> +++ b/util/error.c
> @@ -197,7 +197,11 @@ ErrorClass error_get_class(const Error *err)
>
> const char *error_get_pretty(Error *err)
> {
> - return err->msg;
> + if (err) {
> + return err->msg;
> + } else {
> + return NULL;
> + }
This change belongs to a separate patch, if any. But personally I don't like
it, because it doesn't work very well when error_get_pretty is used in
printf-like function parameters:
Error *err = NULL;
error_report("error: %s", error_get_pretty(err));
will print "error: (null)" which is ugly, in which case the caller need to
check the pointer anyway. And that is the dominant use case for
error_get_pretty in the code base.
IMO the caller can always do this:
err ? error_get_pretty(err) : NULL
in place of your proposed
error_get_pretty(err)
So maybe leave this and change dump_process like above? Or if you insist, make
this hunk a separate patch please.
Fam
> }
>
> void error_report_err(Error *err)
> --
> 2.4.3
>
