loop and event dispatchers. This simplifies code and eliminates a bug,
when kevent dispatcher is called with 0 timeout.
While here, in the main loop call gettimeofday() right after event
dispatcher returns. Otherwise, we are using outdated "timeofday" in
second part of the loop. I don't know any bugs because of that, but
they are possible.
specific code to monitor_inotify.c.
Both monitor_inotify.c and monitor_kqueue.c provide their functions
for adding and removing watches. Prefix these functions with monitor_.
Use newer API for IP_MULTICAST_IF which allows one to specify
interface by index, not by address. Introduced in Linux 3.5, it IMHO should
be available on all systems that declare struct ip_mreqn.
This fixes operation failure when a system has multiple interfaces
with same address, but only on of them is desired. Example:
> grep interface /usr/local/etc/minidlna.conf
network_interface=igb0
> ifconfig igb0
igb0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
ether 0c:c4:7a:xx:xx:xx
inet 10.1.10.3 netmask 0xffffff00 broadcast 10.1.10.255
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
> ifconfig ng0
ng0: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> metric 0 mtu 1454
inet 10.1.10.3 --> 10.1.10.2 netmask 0xffffffff
In such configuration, ng0 would be chosen before this fix.
This has theoretical bug if our collection spans different
filesystems and some filesystems support holes, and some not.
If this ever encountered we should use pathconf(2) and cache
its result for directories.
My guess the goal was to skip files with holes in them. Original commit
590f0761f4, doesn't explain that. If that
is still necessary, better to add lseek(SEEK_DATA) check later.
Some effort was made to unify monitoring via kqueue and via inotify
APIs. Now both provide their implementation of add_watch() function.
I guess there are some logical bugs in vnode_process(). With this commit
it would be better provide code as is, and resolve bugs separately.
The idea is taken from the nginx web server, but much simplified and
almost no copypaste left. This will allow minidlna to use different
event dispatcher APIs, which would be defined at compile time.
My personal goal is to convert minidlna to kqueue(2) on FreeBSD. This
would later allow for kqueue based directory change notification, which
won't conflict with select(2) like the current patch does.
Other platforms will also benefit from the pluggability of the event
system, Linux can switch to epoll(2) or at least to poll(2).
Detailed list of changes:
* event.h [New]
Our internal API to unify different event dispatch systems.
* select.c [New]
Much simplified version of nginx's ngx_select_module.c.
* minidlna.c
- Split out listen socket event processing into separate function
ProcessListen(), which matches event_process_t type.
- Create and initialize struct event for the monitor socket, SSDP
socket, HTTP socket and beacon socket.
- Simplify and make more precise timeout calculation using
helper timeval functions from utils.c. Treat gettimeofday() error
as a fatal event.
- Rip out all stuff related to select(2). Just call event_module.process().
* upnpevents.c
- Embed struct event into upnp_event_notify.
- Merge upnp_event_create_notify() with upnp_event_notify_connect().
Start connecting immediately after socket creation. Garbage collect
now useless ECreated state.
- Make upnp_event_process_notify() of event_process_t type, and use it
as process callback for upnp_event_notify event.
- Looks like we always create upnp_event_notify with existing subscriber,
and never clear it later. Remove checks for obj->sub and assert that it
is never NULL. Simplifies things.
- When switching obj state, add/del it to event dispatcher accrodingly.
- Garbage collect upnpevents_selectfds().
- Garbage collect select(2) related stuff from upnpevents_processfds().
Rename function to upnpevents_gc(), since the remaining functionality
is garbage collecting, not file descriptor processing.
Actually, this can be simplified even more. We can safely close sockets
and free objects immediately, eliminating need for upnpevents_gc(). But
this change would be beyond scope of this commit.
* upnphttp.c, upnphttp.h
Embed struct event into struct upnphttp. Adjust Process_upnphttp() to match
event_process_t type. Add/del to event dispatcher once creating/closing a
socket.
* minissdp.c, minissdp.h
Make ProcessSSDPRequest() of event_process_t type.
* getifaddr.c, getifaddr.h
Make ProcessMonitorEvent() of event_process_t type.
