Benchmarks demonstrated that the idle timer handle approach didn't balance the
load quite fair enough, the majority of new connections still ended up in one
or two processes.
The new approach voluntarily gives up a scheduler timeslice by calling
nanosleep() with a one nanosecond timeout.
Why not sched_yield()? Because on Linux (and this is probably true for other
Unices as well), sched_yield() only yields if there are other processes running
on the same CPU.
nanosleep() on the other hand always forces the process to sleep, which gives
other processes a chance to accept our pending connections.
The OS X version was being checked with the __MAC_OS_X_VERSION_MIN_REQUIRED__
macro, but this value doesn't match the actual SDK version when it is
overridden with the -mmacosx-version-min command line switch.
Adds initial libuv build/platform support for AIX. Builds work using gcc or the
IBM XL C compiler using its gxlc wrapper. Platform support is added for
uv_hrtime, uv_exepath, uv_get_free_memory, uv_get_total_memory, uv_loadavg,
uv_uptime, uv_cpu_info, uv_interface_addresses.
This will make uv_queue_work consistent with other functions, where it's
possible to omit the callback. I'm pretty sure that this is already
implemented for unix systems, although I didn't test the unix part of
uv_queue_work.
Implement a best effort approach to mitigating accept() EMFILE errors.
We have a spare file descriptor stashed away that we close to get below
the EMFILE limit. Next, we accept all pending connections and close them
immediately to signal the clients that we're overloaded - and we are, but
we still keep on trucking.
There is one caveat: it's not reliable in a multi-threaded environment.
The file descriptor limit is per process. Our party trick fails if another
thread opens a file or creates a socket in the time window between us
calling close() and accept().
Fixes#315.
Don't spin in epoll_wait() / kevent() / port_getn() / etc. when we can't
accept() a new connection due to having reached the file descriptor limit.
Pass the error to the connection_cb and let the libuv user deal with it.
Some memory was leaked when the uv_udp_t handle was closed when there were
in-flight send requests with a heap allocated buffer list.
That doesn't happen much in practice. In the common case (writing < 5 buffers),
the buffer list is stored inside the uv_udp_send_t structure, not allocated on
the heap.
