ZeroMQ core engine in C++, implements ZMTP/3.1
Relicensing from LGPL-3.0+ (with custom exceptions) to MPL-2.0 is now complete. libzmq is now distributed under the Mozilla Public License 2.0. Relicensing grants have been collected from all relevant authors, and some functionality has been clean-room reimplemented where that was not possible. In layman terms, the new license provides the same rights and obligations as before. Source files are now tagged using the SPDX license identifier format. Details of the relicensing process can be seen at: https://github.com/zeromq/libzmq/issues/2376 Relicensing grants have been archived at: https://github.com/rlenferink/libzmq-relicense A special thanks to everybody who helped with this long and difficult task, with the process, the reimplementations, the collections and everything else.
New DRAFT (see NEWS for 4.2.0) socket options:
New DRAFT (see NEWS for 4.2.0) zmq_ppoll APIs was added that differs from zmq_poll in the same way that ppoll differs from poll. See doc/zmq_ppoll.txt for details.
Various bug fixes and performance improvements.
New DRAFT (see NEWS for 4.2.0) socket option:
Fixed #4113 - compilation errors on kFreeBSD and GNU/Hurd
Fixed #4086 - excessive amount of socket files left behind in Windows TMP directory
Fixed #4108 - regression that breaks using IPv6 link-local addresses on Linux
Fixed #4078 - compilation errors on Android
Fixed #4074 - compilation error with ulibc and libbsd
Fixed #4060 - stack overflow on Windows x64
Fixed #4051 - various compilation errors on Windows ARM 32bit
Fixed #4043 - various compilation warnings with XCode
Fixed #4038 - return value of zmq_ctx_get changed unintentionally
Security advisories:
Note for packagers: an external, self-contained sha1 library is now included in the source tree under external/sha1/ - it is licensed under BSD-3-Clause and thus it is fully compatible with libzmq's license. It is only used if WebSockets support is enabled, and if neither GnuTLS nor NSS are available.
Note for packagers: an internal reimplementation of strlcpy is now included, for wider platform compatibility. libbsd can be used and is enabled by default if available instead of the internal implementation, for better security maintenance in distros.
Note for packagers: ZeroMQConfig.cmake is now installed in the arch-dependent subdirectory - eg: /usr/lib/x86_64-linux-gnu/cmake/
New DRAFT (see NEWS for 4.2.0) socket type:
New DRAFT (see NEWS for 4.2.0) socket option:
New DRAFT (see NEWS for 4.2.0) zmq_ctx_get_ext/zmq_ctx_set_ext APIs were added to allow enhancing the context options with variable data inputs. See doc/zmq_ctx_get_ext.txt and doc/zmq_ctx_set_ext.txt for details.
New DRAFT (see NEWS for 4.2.0) transport options WS and WSS added for support of WebSockets (and secure WebSockets via TLS) via the ZWS 2.0 protocol. WSS requires the GnuTLS library for TLS support. ZMQ_WSS_ specific socket options were added to support TLS. WebSockets support is disabled by default if DRAFT APIs are disabled.
New DRAFT (see NEWS for 4.2.0) socket type, PEER, which is thread safe and a related zmq_connect_peer function which atomically and thread-safely connects and returns a routing-id.
New DRAFT (see NEWS for 4.2.0) zmq_msg_init_buffer API was added to allow the construction of a message by copying from an existing buffer.
New DRAFT (see NEWS for 4.2.0) zmq_poller_size API was added to allow querying the number of sockets/fds registered in a zmq_poller.
ZMTP 3.1 peers will receive subscribe/cancel on PUB/SUB via commands rather than using the first byte of the payload.
zmq_z85_decode now checks that the input string's length is at least 5 characters and always a multiple of 5 as per API specification.
Fixed #3566 - malformed CURVE message can cause memory leak
Fixed #3567 - missing ZeroMQ_INCLUDE_DIR in ZeroMQConfig.cmake when only static lib is built
Fixed #3576 - CURVE plaintext secrets now stored in libsodium's secure memory
Fixed #3588 - install debug libraries for debug msvc builds with CMake
Fixed #3591 - incorrect ZMQ_MAX_SOCKETS default value in doc
Fixed #3594 - fixed stream_engine use after free due to concurrent heartbeats
Fixed #3586 - error when compiling with MinGW due to usage of MS-specific __except keyword
Fixed #3603 - fixed CMake build on SL6.9
Fixed #3607 - added scripts to ease performance graph generation
Fixed #3608 - fix for IPv4 mapping not supported in DragonFlyBSD
Fixed #3636 - added ENABLE_PRECOMPILED CMake option to fix build with Ninja
Fixed #2862 - UDP engine aborts on networking-related errors from socket syscalls
Fixed #3656 - segfault on sending data from XSUB to XPUB
Fixed #3646 - static-only test run fails
Fixed #3668 - fixed CMAKE_CXX_FLAGS_* regexes on MSVC
Fixed #110 - do not include winsock2.h in public zmq.h header
Fixed #3683 - allow "configure --disable-maintainer-mode"
Fixed #3686 - fix documentation about sockets blocking on send operations
Fixed #3323 - fix behavior of ZMQ_CONFLATE on PUB sockets
Fixed #3698 - fix build on IBM i/PASE/os400
Fixed #3705 - zero-sized messages cause assertion when glibc assertion are on
Fixed #3713 - remove dependency on math library by avoiding std::ceil
Fixed #3694 - build targeting Windows XP is broken
Fixed #3691 - added support for IPC on Windows 10 via AF_UNIX
Fixed #3725 - disable by default test that requires sudo on CMake
Fixed #3727 - fix zmq_poller documentation example
Fixed #3729 - do not check for FD_OOB when using WSAEventSelect on Windows
Fixed #3738 - allow renaming the library in CMake
Fixed #1808 - use AF_UNIX instead of TCP for the internal socket on Windows 10
Fixed #3758 - fix pthread_set_affinity detection in CMake
Fixed #3769 - fix undefined behaviour in array.hpp
Fixed #3772 - fix compiling under msys2-mingw
Fixed #3775 - add -latomic to the private libs flag in pkg-config if needed
Fixed #3778 - fix documentation of zmq_poller's thread safety
Fixed #3792 - do not allow creation of new sockets after zmq_ctx_shutdown
Fixed #3805 - improve performance of CURVE by reducing copies
Fixed #3814 - send subscribe/cancel as commands to ZMTP 3.1 peers
Fixed #3847 - fix building without PGM and NORM
Fixed #3849 - install .cmake file in arch-dependent subdirectory
Fixed #4005 - allow building on Windows ARM/ARM64
CVE-2019-13132: a remote, unauthenticated client connecting to a libzmq application, running with a socket listening with CURVE encryption/authentication enabled, may cause a stack overflow and overwrite the stack with arbitrary data, due to a buffer overflow in the library. Users running public servers with the above configuration are highly encouraged to upgrade as soon as possible, as there are no known mitigations. All versions from 4.0.0 and upwards are affected. Thank you Fang-Pen Lin for finding the issue and reporting it!
New DRAFT (see NEWS for 4.2.0) zmq_socket_monitor_versioned API that supports a versioned monitoring events protocol as a parameter. Passing 1 results in the same behaviour as zmq_socket_monitor. Version 2 of the events protocol allows new events, new metadata, different socket types for the monitors and more. It is described in details in doc/zmq_socket_monitor_versioned.txt
New DRAFT (see NEWS for 4.2.0) zmq_socket_monitor_pipes_stats that triggers a new ZMQ_EVENT_PIPES_STATS to be delivered via zmq_socket_monitor_versioned v2 API, which contains the current status of all the queues owned by the monitored socket. See doc/zmq_socket_monitor_versioned.txt for details.
New DRAFT (see NEWS for 4.2.0) zmq_poller_fd that returns the FD of a thread safe socket. See doc/zmq_poller.txt for details.
New DRAFT (see NEWS for 4.2.0) socket options:
Implemented background thread names for Windows, when the Visual Studio debugger is being used.
Fixed #3358 - test_security_zap failing due to SIGBUS on SPARC64, hard-coded IPC socket binds in tests cause race conditions
Fixed #3361 - enabling GSSAPI support (when using autools) does not work due to regression introduced in 4.2.3
Fixed #3362 - remove documentation for ZMQ_THREAD_PRIORITY context option getter, it's not implemented
Fixed #3363 - tests fail to build due to stricter compiler printf validation in new versions of GCC
Fixed #3367 - try to infer cacheline size at build time, first with getconf LEVEL1_DCACHE_LINESIZE, and then by reading /sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size (autoconf only), and only then falling back to the previous default of 64 bytes. Avoids false sharing on POWER and s390x. Import ax_func_posix_memalign.m4 as a more reliable check for posix_memalign presence on some unix platforms. Prefer c++11 atomic primitives to compiler intrinsics, when both are available, as the former is more reliable. Set test_pair_ipc and test_rebind_ipc to XFAIL on GNU/Hurd due to non-functioning getsockname on AF_UNIX.
Fixed #3370 - Make queue length and HWM state observable
Fixed #3373 - performance regression in zmq_poll on CentOS 6/7
Fixed #3375 - assign names to all pthreads created by the library to ease debugging
Fixed #3376 - assigned random TIPC port is not returned by ZMQ_LAST_ENDPOINT
Fixed #3385 - TCP port in ZMQ_LAST_ENDPOINT depends on global locale
Fixed #3404 - use std::condition_variable_any when possible
Fixed #3436 - reconnect interval exponential backoff and may lead to integer overflows
Fixed #3440 - improve zmq_proxy performance by batching of up to 1000 consecutive messages (if any) and add perf/proxy_thr tool
Fixed #3451 - fix support of /dev/poll on Solaris
Fixed #3452 - strnlen may not be available
Fixed #1462 - test failure in test_filter_ipc due to invalid system groups
Fixed #3269 - Boost.ASIO integration stopped working with v4.3.0
Fixed #3479 - ZeroMQ does not build for QNX 6.6 with CMake
Fixed #3481 - add
Fixed #3491 - build broken on Fedora 30
Fixed #3494 - ZeroMQConfig.cmake fails if shared libraries are not built
Fixed #3498 - syntax error on Windows related to socket descriptor type
Fixed #3500 - PLAIN HELLO message incorrectly uses WELCOME literal, regression introduced in 4.3.0
Fixed #3517 - configure errors because of syntax errors in the use of test shell command
Fixed #3521 - document how to achieve high performance with the PGM transport
Fixed #3526 - failure case behavior unclear in zmq_msg_send documentation
Fixed #3537 - fix build on z/OS by using pthread_equal instead of comparing variables directly
Fixed #3546 - CMake links with librt on MinGW which is not available
Many coding style, duplication, testing and static analysis improvements.
CVE-2019-6250: A vulnerability has been found that would allow attackers to direct a peer to jump to and execute from an address indicated by the attacker. This issue has been present since v4.2.0. Older releases are not affected. NOTE: The attacker needs to know in advance valid addresses in the peer's memory to jump to, so measures like ASLR are effective mitigations. NOTE: this attack can only take place after authentication, so peers behind CURVE/GSSAPI are not vulnerable to unauthenticated attackers. See https://github.com/zeromq/libzmq/issues/3351 for more details. Thanks to Guido Vranken for uncovering the issue and providing the fix!
Note for packagers: as pkg-config's Requires.private is now used to properly propagate dependencies for static builds, the libzmq*-dev or zeromq-devel or equivalent package should now depend on the libfoo-dev or foo-devel packages of all the libraries that zmq is linked against, or pkg-config --libs libzmq will fail due to missing dependencies on end users machines.
Fixed #3351 - remote code execution vulnerability.
Fixed #3343 - race condition in ZMQ_PUSH when quickly disconnecting and reconnecting causes last part of multi-part message to get "stuck" and resent by mistake to the new socket.
Fixed #3336 - set Requires.private in generate pkg-config file.
Fixed #3334 - set TCP_NODELAY after connect() on Windows for the I/O socket.
Fixed #3326 - assert on Android when opening a socket and disabling WiFi.
Fixed #3320 - build failure on OpenBSD with GCC.
The following DRAFT APIs have been marked as STABLE and will not change anymore:
The build-time configuration option to select the poller has been split, and new API_POLLER (CMake) and --with-api-poller (autoconf) options will now determine what system call is used to implement the zmq_poll/zmq_poller APIs. The previous POLLER and --with-poller options now only affects the internal I/O thread. In case API_POLLER is not specified, the behaviour keeps backward compatibility intact and will be the same as with previous releases.
The non-default "poll" poller for the internal I/O thread (note: NOT for the zmq_poll/zmq_poller user APIs!) has been disabled on Windows as WSAPoll does not report connection failures. For more information see:
New epoll implementation for Windows, using the following implementation: https://github.com/piscisaureus/wepoll/tree/v1.5.4 To use this, select "epoll" as the poller option in the build system. Note for distributors: the wepoll source code is embedded and distributed. It is licensed under the BSD-2-Clause and thus it is compatible with LGPL-3.0. Note that, if selected at build time, the license text must be distributed with the binary in accordance to the license terms. A copy can be found at: external/wepoll/license.txt
The pre-made Visual Studio solutions file are deprecated, and users are encouraged to use the CMake solution generation feature instead.
New DRAFT (see NEWS for 4.2.0) socket options:
New perf tool, perf/benchmark_radix_tree, to measure the performance of the different internal implementations of the trie algorithm used to track subscriptions. Requires a compiler that supports C++11.
New autoconf flag "--enable-force-CXX98-compat" which will force -std=gnu++98 and, if the compiler supports them (clang++ at the moment), it will also add -Wc++98-compat -Wc++98-compat-pedantic so that compatibility with C++98 can be tested.
Many, many coding style, duplication and static analysis improvements.
Many, many improvements to the CMake build system, especially on Windows.
Many, many improvements to unit tests.
Fixed #3036 - Compilation error when -pedantic is used.
Fixed #3028 - Failure when zmq_poller_destroy is called after zmq_ctx_term.
Fixed #2989 - CMake: Linker PDB install rule does not work when Visual Studio generators are used.
Fixed #3045 - configure.ac: search for dladdr only when using libunwind.
Fixed #3060 - REQ sockets terminate TCP connection after first heartbeat if ZMQ_HEARTBEAT_IVL is set.
Fixed #2212 - UDP: need ability to specify bind address separately from multicast address for multi-homed hosts.
Fixed #2891 - UDP: address name resolution is limited to dotted IPv4 rather than being capable of IPv4, IPv6, and hostname lookup.
Fixed #3085 - autoconf/CMake getrandom test does not check if it's working but only for its presence.
Fixed #3090 - compilation broken with Solaris Studio.
Fixed #3094 - UDP: pass interface via IP[V6]_MULTICAST_IF if provided.
Fixed #3061 - implement ZMTP 3.1 ping/pong context sending/receiving.
Fixed #2188 - Added documentation for new zmq_poller API.
Fixed #3088 - zmq_poller_add/zmq_poller_modify should reject invalid events arguments.
Fixed #3042 - Fixed compilation on ARM with ZMQ_ATOMIC_PTR_MUTEX.
Fixed #3107 - test_immediate_3/test_reconnect_inproc do not terminate with POLL as the I/O thread poller under Windows.
Fixed #3046 - Aborts when iOS abuses EBADF to report a socket has been reclaimed.
Fixed #3136 - Cannot set ZMQ_HEARTBEAT_TTL to more than 655.3 seconds.
Fixed #3083 - link with -latomic when needed.
Fixed #3162 - build failure with MUSL libc.
Fixed #3158 - -1 value of ZMQ_RECONNECT_IVL was not correctly handled on some platforms.
Fixed #3170 - improved documentation for ZMQ_PAIR.
Fixed #3168 - correctly use symbols map on Debian/kFreeBSD and Debian/HURD to avoid exporting standard library symbols.
Fixed #3168 - correctly process ZMTP 3.1 cancel/subscribe commands.
Fixed #3171 - improve documentation for ZMQ_CONFLATE.
Fixed #2876 - stack overflow on Windows 64.
Fixed #3191 - race condition with received message causes ZMQ_CONNECT_ROUTING_ID to be assigned to wrong socket.
Fixed #3005 - added documentation for new zmq_timers_* API.
Fixed #3222 - use /Z7 debug on Release builds too on Windows (CMake).
Fixed #3226 - possible PGM receiver crash.
Fixed #3236 - UDP dish socket can't bind to a multicast port already in use.
Fixed #3242 - improve HWM documentation.
Fixed #2488 - improve zmq_msg_send doc return value documentation.
Fixed #3268 - HWM in ZMQ_DGRAM socket does not respect multipart message.
Fixed #3284 - added support for ZMQ_MULTICAST_HOPS with UDP sockets.
Fixed #3245 - use-after-free reported in zmq::pipe_t::terminate.
Fixed #1400 - use patricia trie for subscription to improve performances and memory usage. Note: only active in DRAFT builds for now.
Fixed #3263 - fix abort on Windows when a large TCP read is requested and fails.
Fixed #3312 - fix build on Android Things 1.06 with Termux.
Fixed #3018 - fix backward-incompatible change in the NULL auth mechanism that slipped in 4.2.3 and made connections with a ZAP domain set on a socket but without a working ZAP handler fail. See ZMQ_ZAP_ENFORCE_DOMAIN and RFC27.
Fixed #3016 - clarify in zmq_close manpage that the operation will complete asynchronously.
Fixed #3012 - fix CMake build problem when using LIBZMQ_WERROR and a compiler other than GCC.
New DRAFT (see NEWS for 4.2.0) socket options:
New DRAFT (see NEWS for 4.2.0) context options:
New DRAFT API zmq_stopwatch_intermediate which returns the time elapsed without stopping the stopwatch.
TIPC: support addressing TIPC Port Identity addresses.
Added CMake option to disable tests: BUILD_TESTS
Added CMake and autotools make targets to support clang-formatter: make clang-format, clang-format-check and clang-format-diff to help developers make sure their code conforms to the style guidelines
For distributors: a new test framework has been added, which includes a copy of the Unity source code. This source code library is distributed under the MIT license and thus is compatible with libzmq's LGPL3.
Fixed #2867 - add ZeroMQConfig.cmake.in to distributable tarball
Fixed #2868 - fix OpenBSD build
Fixed #2870 - fix VC++ 11.0 (VS2012) build
Fixed #2879 - prevent duplicate connections on PUB sockets
Fixed #2872 - fix CMake tests on Windows
Fixed #2895 - fix assert on Windows with POLL
Fixed #2920 - fix Windows build with Intel compiler
Fixed #2930 - use std::atomic when available with VC++ and VS2015
Fixed #2910 - fix race condition with ZMQ_LINGER socket option
Fixed #2927 - add support for ZMQ_XPUB_NODROP on ZMQ_RADIO
Fixed #2820 - further clarify ZMQ_XPUB_VERBOSE(R) documentation.
Fixed #2911 - ZMQ_DISH over UDP triggers errno_assert() after hitting watermark
Fixed #2942 - ZMQ_PUB crash when due to high volume of subscribe and unsubscribe messages, an unmatched unsubscribe message is received in certain conditions
Fixed #2946 - fix Windows CMake build when BUILD_SHARED is off
Fixed #2960 - fix build with GCC 8
Fixed #2967 - fix race condition on thread safe sockets due to pthread condvar timeouts on OSX
Fixed #2977 - fix TIPC build-time availability check to be more relaxed
Fixed #2966 - add support for WindRiver VxWorks 6.x
Fixed #2963 - fix some PVS Studio static analysis warnings
Fixed #2983 - fix MinGW cross-compilation
Fixed #2991 - fix mutex assert at shutdown when the zmq context is part of a class declared as a global static
API change: previously ZMQ_POLLOUT on a ZMQ_ROUTER socket returned always true due to how the type works. When ZMQ_ROUTER_MANDATORY is set, sending fails when the peer is not available, but ZMQ_POLLOUT always returns true anyway, which does not make sense. Now when ZMQ_ROUTER_MANDATORY is set, ZMQ_POLLOUT on a ZMQ_ROUTER will return true only if at least one peer is available. Given ZMQ_POLLOUT with ZMQ_ROUTER was not usable at all previously, we do not consider this a breakage warranting a major or minor version increase.
ZMQ_IDENTITY has been renamed to ZMQ_ROUTING_ID and ZMQ_CONNECT_RID has been renamed to ZMQ_CONNTECT_ROUTING_ID to disambiguate. ZMQ_IDENTITY and ZMQ_CONNECT_RID are still available to keep backward compatibility, and will be removed in a future release after further advance notice.
DRAFT API change: zmq_poller_wait, zmq_poller_wait_all and zmq_poller_poll have been changed to be inline with other existing APIs that have a timeout to return EAGAIN instead of ETIMEDOUT as the errno value. See #2713 for details.
Existing non-DRAFT socket types ZMQ_REP/REQ, ZMQ_ROUTER/DEALER and ZMQPUB/SUB, that were previously declared deprecated, have been reinstated as stable and supported. See #2699 for details.
Tweetnacl: add support for, and use preferably if available, getrandom() as a simpler and less error-prone alternative to /dev/urandom on OSes where it is available (eg: Linux 3.18 with glibc 2.25).
Curve: all remaining traces of debug output to console are now removed, and new DRAFT events are available to properly debug CURVE, PLAIN, GSSAPI and ZAP events and failures. See below for details on the new events.
New DRAFT (see NEWS for 4.2.0) socket options:
New DRAFT (see NEWS for 4.2.0) context options:
New DRAFT (see NEWS for 4.2.0) message property name definitions to facilitate the use of zmq_msg_gets:
New DRAFT (see NEWS for 4.2.0) API zmq_socket_get_peer_state, to be used to query the state of a specific peer (via routing-id) of a ZMQ_ROUTER socket.
New DRAFT (see NEWS for 4.2.0) Socket Monitor events:
New DRAFT (see NEWS for 4.2.0) zmq_proxy_steerable command 'STATISTICS' to retrieve stats about the amount of messages and bytes sent and received by the proxy. See doc/zmq_proxy_steerable.txt for more information.
Add new autoconf --disable-libunwind option to stop building with libunwind even if it is available.
Add new autoconf --disable-Werror option to avoid building with the Werror flag.
Use pkg-config as the first method for finding and building with external optional dependencies such as libnorm, libpgm and gssapi.
On Posix platform where the feature is available, name the ZMQ background threads to simplify debugging: "ZMQbg/<num_thread>"
Improve performance of zmq_poller_* (and zmq_poll and zmq_proxy when building with DRAFT APIs enabled).
The TCP unit tests have been refactored to bind and connect to random ports rather than hard-coded ones, to allow running tests in parallel. There are 6 exceptions where it is necessary to use an hard-coded port to test specific code paths that would not be exercised when binding to a wildcard port. These are listed in tests/testutil.hpp so that distributions can easily patch them if they wish to and so that they can be unique across all the tests, allowing parallel runs. The IPC unit tests have been changed as well to use unique socket file names per test, where before there were some clashes.
Fixed #2349 - fix building with libsodium when using CMake
Fixed #2334 - do not assert when tuning socket options fails due to network errors, but simply retry again when connecting or send a socket monitor ZMQ_EVENT_ACCEPT_FAILED event when binding
Fixed #2341 - fix source files path in VS2015 solution
Fixed #2344 - Note that on Windows with VS2012 it is mandatory to increase the default stack size to at least 2MB
Fixed #2348 - ZMQ_ROUTER send with ZMQ_ROUTER_MANDATORY can be stuck in case of network problem
Fixed #2358 - occasional abort on zmq_connect on Windows
Fixed #2370 - zmq_curve_keypair should return an error on failure rather than ignoring them and always returning 0
Fixed #2452 - __STDC_LIMIT_MACROS before precompiled headers causes VC++ warning
Fixed #2457 - fix building with libsodium in Visual Studio solutions
Fixed #2466 - add const qualifier to internal and public API that does not modify parameters
Fixed #2471 - do more checks for OOM conditions when dynamic allocations is used
Fixed #2476 - assertion causes abort after ZAP stop at shutdown
Fixed #2479 - improve zmq_poller performance on Windows
Fixed #2481 - potential memory leaks due to ZMTP handshake failures
Fixed #2531 - ZMQ_GSSAPI_PRINCIPAL sockopt has no effect on client side
Fixed #2535 - add BUILD_SHARED and BUILD_STATIC options to CMake, both on by default, to toggle shared and static library builds
Fixed #2537 - use SYSTEM_CLOCK on OSX and CLOCK_MONOTONIC elsewhere for internal timers to avoid races
Fixed #2540 - new zmq_poller used by zmq_poll without DRAFTs
Fixed #2552 - Fix WITH_DOC CMake build to avoid checking for asciidoc if the option is disabled
Fixed #2567 - Memory leak in REP socket handling
Fixed #2579 - Compilation issue on Windows with CMake + ninja
Fixed #2588 - SIGBUS under 64-bit SunOS Sparc
Fixed #2590 - crash when using ZMQ_IMMEDIATE and ZMQ_LINGER to non-zero
Fixed #2601 - XPUB_MANUAL subscriptions not removed on peer term
Fixed #2602 - intermittent memory leak for ZMQ_REQ/REP send/recv
Fixed #2608 - CURVE server (connect) fails when client rebinds
Fixed #2610 - print backtraces in mutual exclusion to avoid mixing different traces
Fixed #2621 - add missing CMake files to distributable tarball
Fixed #2630 - improve compatibility with OpenBSD w.r.t. IPV6_V6ONLY
Fixed #2638 - note in INSTALL that when using Windows builds on Linux with Wine it is necessary to increase the minimum TCP buffers
Fixed #2632 - Fix file descriptor leak when using Tweetnacl (internal NACL implementation) instead of Libsodium, and fix race condition when using multiple ZMQ contexts with Tweetnacl
Fixed #2681 - Possible buffer overflow in CURVE mechanism handshake. NOTE: this was protected by an assert previously, so there is no security risk.
Fixed #2704 - test_sockopt_hwm fails occasionally on Windows
Fixed #2701 - pgm build via cmake doesn't link libzmq with libpgm
Fixed #2711 - ZAP handler communication errors should be handled consistently
Fixed #2723 - assertion in src\select.cpp:111 or hang on zmq_ctx_destroy on Windows
Fixed #2728 - fix support O_CLOEXEC when building with CMake
Fixed #2761 - improve compatibility with TrueOS (FreeBSD 12)
Fixed #2764 - do not unlink IPC socket files when closing a socket to avoid race conditions
Fixed #2770 - support lcov 1.13 and newer
Fixed #2787 - add libiphlpapi to PKGCFG_LIBS_PRIVATE for static mingw builds
Fixed #2788 - document that adding -DZMQ_STATIC is required for Windows static builds with Mingw
Fixed #2789 - description of zmq_atomic_counter_value return value is cloned from zmq_atomic_counter_new
Fixed #2791 - fix building with DRAFT APIs on CentOS 6
Fixed #2794 - router_t methods should not allocate memory for lookup in outpipes
Fixed #2809 - optimize select() usage on Windows
Fixed #2816 - add CMake and autoconf check for accept4, as it is not available on old Linux releases, and fallback to accept + FD_CLOEXEC
Fixed #2824 - ZMQ_REQ socket does not report ZMQ_POLLOUT when ZMQ_REQ_RELAXED is set
Fixed #2827 - add support for Haiku
Fixed #2840 - fix building with VS2008
Fixed #2845 - correct the ZMQ_LINGER documentation to accurately reflect that the default value is -1 (infinite). It never was 30 second in any released version, it was only changed briefly and then changed back, but the manpage was not reverted.
Fixed #2861 - CMake/MSVC: export ZMQ_STATIC when needed.