Re: [libvirt] [PATCH 01/13] Introduce a new public API for domain events

The current API for domain events has a number of problems - Only allows for domain lifecycle change events - Does not allow the same callback to be registered multiple times - Does not allow filtering of events to a specific domain This introduces a new more general purpose domain events API typedef enum { VIR_DOMAIN_EVENT_ID_LIFECYCLE = 0, /* virConnectDomainEventCallback */ ...more events later.. } int virConnectDomainEventRegisterAny(virConnectPtr conn, virDomainPtr dom, /* Optional, to filter */ int eventID, virConnectDomainEventGenericCallback cb, void *opaque, virFreeCallback freecb); int virConnectDomainEventDeregisterAny(virConnectPtr conn, int callbackID); Since different event types can received different data in the callback, the API is defined with a generic callback. Specific events will each have a custom signature for their callback. Thus when registering an event it is neccessary to cast the callback to the generic signature

diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index 0d1b5b5..62a51ea 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -1837,6 +1837,40 @@ int virDomainGetJobInfo(virDomainPtr dom, int virDomainAbortJob(virDomainPtr dom); +/* A generic callback definition. Specific events usually have a customization + * with extra parameters */ +typedef void (*virConnectDomainEventGenericCallback)(virConnectPtr conn, + virDomainPtr dom, + void *opaque); + +/* Use this to cast the event specific callback into the generic one + * for use for virDomainEventRegister */ +#define VIR_DOMAIN_EVENT_CALLBACK(cb) ((virConnectDomainEventGenericCallback)(cb))

+ +typedef enum { + VIR_DOMAIN_EVENT_ID_LIFECYCLE = 0, /* virConnectDomainEventCallback */ + + /* + * NB: this enum value will increase over time as new events are + * added to the libvirt API. It reflects the last event ID supported + * by this version of the libvirt API. + */ + VIR_DOMAIN_EVENT_ID_LAST +} virDomainEventID; + + +/* Use VIR_DOMAIN_EVENT_CALLBACK() to cast the 'cb' parameter */ +int virConnectDomainEventRegisterAny(virConnectPtr conn, + virDomainPtr dom, /* Optional, to filter */ + int eventID, + virConnectDomainEventGenericCallback cb, + void *opaque, + virFreeCallback freecb); + +int virConnectDomainEventDeregisterAny(virConnectPtr conn, + int callbackID); + #ifdef __cplusplus } #endif