[libvirt] the arguments of qemudDispatchServerEvent

[Eric Blake]

On 08/14/2012 09:35 AM, mzawdx wang wrote:
> Hi all:
>        I am now reading the source codes of libvirt with version 0.9.2 ,

You'd be better off investigating the source code of libvirt.git (the
current development is working towards 0.10.0 as the successor to the
released 0.9.13); 0.9.2 is quite old.

> and be stuck by the function "qemudDispatchServerEvent". as you can see:
> static void
> qemudDispatchServerEvent(int watch, int fd, int events, void *opaque) {

In fact, in the meantime, this function was deleted in commit df0b57a95
(0.9.3) as part of using a newer RPC framework under src/rpc.

> ...
> }
> 
> My question is : except for the argument "void *opaque"， when and how the
> other three arguments (int watch, int fd, int events) being incoming ?
> 
> For it is a static function, I look through the source file "libvirt.c" and
> find no answer .
> Could someone give me a help ?

If you insist on debugging 0.9.2, look at
daemon/libvirtd.c:qemudNetworkEnable, which passes the address of
qemudDispatchServerEvent as a callback pointer to virEventAddHandle.
Thus, any time a poll() on the connection socket completes,
qemudDispatchServerEvent() will be called with the information learned
from that poll.  In particular,
src/util/event_poll.c:virEventPollDispatchTimeouts() is a location that
calls the callback function.

-- 
Eric Blake   eblake at redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 620 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20120814/8e0e06bf/attachment-0001.sig>