Solution:
1. Use optional name parameter in thread_t::start for operating
systems that have thread names.
2. Give start_thread() an optional name parameter for the
thread's name. If this parameter is set, it will be appended to "0MQ:".
If not set, "0MQ" will be used as the thread's name.
3. Give epoll the ability to name its thread. Then use this in
io_thread and reaper to name them.
Solution: remove documents and tests for ZMQ_THREAD_PRIORITY getter. It
never worked and can never work as it has the same value as a get-only
option ZMQ_SOCKET_LIMIT. It cannot be changed without breaking ABI.
Note that the setter works fine as ZMQ_SOCKET_LIMIT is get-only.
The zero copy decoding strategy implemented for 4.2.0 can lead to a large
increase of main memory usage in some cases (I have seen one program go up to
40G from 10G after upgrading from 4.1.4). This commit adds a new option to
contexts, called ZMQ_ZERO_COPY_RECV, which allows one to switch to the old
decoding strategy.
* Background thread scheduling
- add ZMQ_THREAD_AFFINITY ctx option; set all thread scheduling options
from the context of the secondary thread instead of using the main
process thread context!
- change ZMQ_THREAD_PRIORITY to support setting NICE of the background
thread when using SCHED_OTHER
Solution: add a crypto [de-]initialiser, refcounted and serialised
through critical sections.
This is necessary as utility APIs such as zmq_curve_keypair also
call into the sodium/tweetnacl libraries and need the initialisation
outside of the zmq context.
Also the libsodium documentation explicitly says that sodium_init
must not be called concurrently from multiple threads, which could
have happened until now. Also the randombytes_close function does
not appear to be thread safe either.
This change guarantees that the library is initialised only once at
any given time across the whole program.
Fixes#2632
Solution: don't set thread name on Android
Setting a thread name on Android may fail with "permission
denied" error and abort the process due to failed assertion.
Tested on Android 5 and 6 (two phones).
Strangely enough, it only happens on signed APKs and is fine
in debug. Using JeroMQ is not an option as we need TCP keepalive
settings and authentication which JeroMQ doesn't support.
Solution: use pthread API to set the name. For now call every thread
"ZMQ b/g thread". Would be nice to number the I/O threads and name
explicitly the reaper thread, but in reality a bit of internal API
churn would be necessary, so perhaps it's not worth it.
This is useful when debugging a process with many threads.
Solution: add a zmq_assert to check if the ephemeral sockets created
to drain the queue of pending inproc connecting sockets was allocated
successfully.
Solution: check if the connecting inproc socket has been closed
before trying to send the identity.
Otherwise the pipe will be in waiting_for_delimiter state causing
writes to fail and the connect to assert when the context is being
torn down and the pending inproc connects are resolved.
Add test case that covers this behaviour.
libsodium calls abort() when /dev/urandom can't be found
even if one creates ZeroMQ context before calling chroot()[1].
This happens because crypto gets initialized on handshake,
and at that moment the process is already chroot'ed.
Solution: initialize cryptographic libraries in ctx
randombytes_close() is already there in the destructor.
[1] https://download.libsodium.org/doc/usage/index.html
- they have no copyright / license statement
- they are in some randomish directory structure
- they are a mix of postable and non-portable files
- they do not conform to conditional compile environment
Overall, it makes it rather more work than needed, in build scripts.
Solution: clean up tweetnacl sauce.
- merged code into single tweetnacl.c and .h
- standard copyright header, DJB to AUTHORS
- moved into src/ along with all other source files
- all system and conditional compilation hidden in these files
- thus, they can be compiled and packaged in all cases
- ZMQ_USE_TWEETNACL is set when we're using built-in tweetnacl
- HAVE_LIBSODIUM is set when we're using external libsodium
It's unclear which we need and in the source code, conditional code
treats tweetnacl as a subclass of libsodium, which is inaccurate.
Solution: redesign the configure/cmake API for this:
* tweetnacl is present by default and cannot be enabled
* libsodium can be enabled using --with-libsodium, which replaces
the built-in tweetnacl
* CURVE encryption can be disabled entirely using --enable-curve=no
The macros we define in platform.hpp are:
ZMQ_HAVE_CURVE 1 // When CURVE is enabled
HAVE_LIBSODIUM 1 // When we are using libsodium
HAVE_TWEETNACL 1 // When we're using tweetnacl (default)
As of this patch, the default build of libzmq always has CURVE
security, and always uses tweetnacl.
And I'm on a reasonably sized laptop. I think allocating INT_MAX
memory is dangerous in a test case.
Solution: expose this as a context option. I've used ZMQ_MAX_MSGSZ
and documented it and implemented the API. However I don't know how
to get the parent context for a socket, so the code in zmq.cpp is
still unfinished.
