于 2011年01月07日 00:50, Eric Blake 写道:
On 01/06/2011 08:43 AM, Osier Yang wrote:
Add VM name/UUID in log for domain related APIs. Format: "dom=%p, (VM: name=%s, uuid=%s), param0=%s, param1=%s
*src/libvirt.c (introduce two macros: VIR_DOMAIN_DEBUG, and VIR_DOMAIN_DEBUG0) --- src/libvirt.c | 243 +++++++++++++++++++++++++++++++++++++++----------------- 1 files changed, 169 insertions(+), 74 deletions(-)
diff --git a/src/libvirt.c b/src/libvirt.c index ee2495a..bdf9896 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -312,6 +312,39 @@ static struct gcry_thread_cbs virTLSThreadImpl = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL };
+#define VIR_DOMAIN_DEBUG(dom, fmt, ...) { \ + do { \
No need to use both an outer '{}' and an inner 'do {}while(0);'. The more idiomatic expression is do{}while(0) (note the missing trailing ; in the macro definition, since it is supplied instead by the statement where the macro is used - you had one caller that missed this) and no extra {} (if there is any worry about ever using this as a one-line statement in a brace-less if statement, then it is essential to let the caller supply a trailing ; without it expanding into two statements).
But in this case, we can go one step further - VIR_DOMAIN_DEBUG is always called at the top level (never part of a compound statement), and we require C99 (decl-after-statement is not an issue even if VIR_DOMAIN_DEBUG(); is not the first statement), so we can avoid introducing a new scope altogether. We already use compiler warnings to ensure we don't accidentally shadow any variables, but we can be even safer by making the macro-specific declarations less likely to collide.
+ virUUIDFormat(dom->uuid, uuidstr); \
Just in case dom is complex, we're safer to properly parenthesize within the macro (although I don't think any of the existing uses of dom are complex).
+#define VIR_DOMAIN_DEBUG0(dom) { \
Shorter to define this as as a wrapper around VIR_DOMAIN_DEBUG, rather than repeating logic (plus it means fewer places to touch if we change the layout in the future).
Thanks for the detailed knowledge above.
@@ -2100,7 +2133,10 @@ error: virDomainPtr virDomainLookupByUUID(virConnectPtr conn, const unsigned char *uuid) { - DEBUG("conn=%p, uuid=%s", conn, uuid); + char uuidstr[VIR_UUID_STRING_BUFLEN]; + virUUIDFormat(uuid, uuidstr); + + DEBUG("conn=%p, uuid=%s", conn, uuidstr);
Good catch. Maybe we should favor VIR_DEBUG over DEBUG, (they are identical macros, but the latter is marked as legacy in logging.h), but that doesn't impact this patch.
Everything else looks like straight-forward mechanical conversions.
Therefore, ACK with this squashed in (I used diff -b, to focus on the non-indentation changes; the final patch looks better), and I'm pushing it.
Great, thanks. Regards Osier