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(a)redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org