Hi, all,
I'm using libevent for my project. But I can't find an easy way to
make sure a bufferevent structure is still legal when I want to
call bufferevent_write to send some info back to client.
In my project, the event_base_dispatch() runs in main thread, and
when it receives some packets from a client, a structure Message
is constructed and pushed to a message queue. There is a thread
pool, and each thread fetches Message out from the queue, then
processes them, and sends some info back to clients. Structure
Message records the bufferevent that it comes from, so in those
processing threads, I call bufferevent_write to send info
back. (Hope I make this clear).
But the client may close the connection, which results in that
bufferevent structure is freed in event call back function (main
thread). This results in crash in processing-threads when they try
to send info back using a freed bufferevent.
The way I use is putting bufferevent_free and
bufferevent_write in a critical section (a global lock), and
- when there is a connection established, record the newly created
bufferevent (say a set)
- in the critical section of bufferevent_free, delete that bev
from that set
- in the critical section of bufferevent_write, check whether that
bev is in that set, if so call bufferevent_write
But I think maybe this is not efficient, is there an easy way in
libevent? Does bufferevent_lock/bufferent_unlock help?
Thanks and Regards,
Wenliang
