Erlang/OTP 26.0-rc2 is the second release candidate of three before the OTP 26.0 release.
The release candidate 2 fixes some bugs found in the first release candidate and there are also a few additional features.
The intention with this release is to get feedback from our users. All feedback is welcome, even if it is only to say that it works for you.
We encourage users to try it out and give us feedback either by creating an issue here Issues · erlang/otp · GitHub or by posting to Erlangforums.
All artifacts for the release can be downloaded from the Erlang/OTP Github release and you can view the new documentation at Erlang/OTP 26.0. You can also install the latest release using kerl like this: kerl build 26.0-rc2 26.0-rc2.
Erlang/OTP 26 is a new major release with new features, improvements as well as a few incompatibilities. Some of the new features are highlighted below.
Many thanks to all contributors!
Below are some highlights of the release:
Highlights RC2
Parsetools
-
Leex
has been extended with optional column number support.
Stdlib
- The family of enumeration functions in module
lists
has been extended with
enumerate/3
that allows a step value to be supplied. - Update Unicode to version 15.0.0.
-
proc_lib:start*/*
has become synchronous when the
started process fails. This requires that a failing
process use a new functionproc_lib:init_fail/2,3
, or
exits, to indicate failure. All OTP behaviours have
been fixed to do this.
Dialyzer
- Added the new built-in type
dynamic()
introduced in EEP 61, PR introducing EEP 61 improving support for gradual type checkers.
SSL
- Change the client default
verify
option toverify_peer
.
Note that this makes it mandatory to also supply trusted CA certificates or explicitly set
verify
toverify_none
. This also applies when using the so called
anonymous test cipher suites defined in TLS versions pre TLS-1.3.
Highlights RC1
The Shell
There are a lot of new features and improvements in the Erlang shell:
- auto-complete of variables, record names, record fields names, map keys, function parameter types and filenames.
- Open external editor in the shell to edit
the current expression. - defining records (with types), functions, specs and types in the shell.
New terminal
- The TTY/terminal subsystem has been rewritten.
Windows users will notice thaterl.exe
has the same
functionality as a normal Unix shell and thatwerl.exe
is just a
symlink toerl.exe
. This makes the Windows Erlang terminal
experience identical to that of Unix.
Compiler and JIT optimizations:
-
Creation and matching of binaries with segments of fixed sizes have been optimized.
-
Creation and matching of UTF-8 segments have been optimized.
-
Appending to binaries has been optimized.
-
The compiler and JIT now generate better code for creation of small maps where all keys
are literals known at compile time. -
Thanks to the optimizations above the performance of the
base64
module has been
significantly improved. For example, on an x86_64 system with the JIT both encode and
decode are almost three times faster than in Erlang/OTP 25.
Maps
-
Map comprehensions as suggested in EEP 58 has now been
implemented. -
Some map operations have been optimized by changing the
internal sort order of atom keys. This changes the
(undocumented) order of how atom keys in small maps are
printed and returned bymaps:to_list/1
andmaps:next/1
.
The new order is unpredictable and may change between
different invocations of the Erlang VM. -
Introducing the new function
maps:iterator/2
for creating an interator
that return the map elements in a deterministic order.
There are also new modifiersk
andK
for the format
string inio:format()
to support printing map elements
ordered.
Dialyzer
- Dialyzer has a new incremental mode that be invoked by
giving the--incremental
option when running Dialyzer.
This new incremental mode is likely to become the
default in a future release.
Misc ERTS, Stdlib, Kernel, Compiler
-
Multi time warp mode is now enabled by default.
This assumes that all code executing on the system is
time warp safe. -
Support for UTF-8 atoms and strings in the NIF
interface including new functionsenif_make_new_atom
,
enif_make_new_atom_len
andenif_get_string_length
. -
The BIFs
min/2
andmax/2
are now allowed to be used in
guards and match specs. -
Improved the selective receive optimization, which can
now be enabled for references returned from other
functions. This greatly improves the performance of
gen_server:send_request/3
,gen_server:wait_response/2
,
and similar functions. -
New trace feature
call_memory
. Similar tocall_time
tracing, but instead of measure accumulated time in
traced functions it measures accumulated heap space
consumed by traced functions. It can be used to compare
how much different functions are contributing to
garbage collection being triggered. -
It is no longer necessary to enable a feature in the
runtime system in order to load modules that are using
it. It is sufficient to enable the feature in the
compiler when compiling it. -
inet:setopts/2
has got 3 new options:reuseport
,reuseport_lb
andexclusiveaddruse
. -
Fix so that
-fno-omit-frame-pointer
is applied to all
of the Erlang VM when using the JIT so that tools, such
asperf
, can crawl the process stacks. -
In the
lists
module, the zip family of functions now takes
options to allow handling lists of different lengths. -
Added the
zip:zip_get_crc32/2
function to retrieve the
CRC32
checksum from an opened ZIP archive.
gen_server
optimized by caching callback functions -
The modules Erlang DNS resolver
inet_res
and helper
modules have been updated for RFC6891; to handle OPT RR
with DNSSEC OK (DO) bit. -
Introduced
application:get_supervisor/1
. -
Cache OTP boot code paths, to limit how many folders
that are being accessed during a module lookup. Can be
disabled with-cache_boot_path false
.
SSL
-
Support for Kernel TLS (kTLS), has been added to the
SSL application, for TLS distribution (-proto_dist
inet_tls
), the SSL option{ktls, true}
. -
Improved error checking and handling of ssl options.
-
Mitigate memory usage from large certificate chains by
lowering the maximum handshake size. This should not
effect the common cases, if needed it can be configured
to a higher value. -
For security reasons the
SHA1
andDSA
algorithms are no longer among the default values. -
Add encoding and decoding of
use_srtp
hello extension
to facilitate forDTLS
users to implementSRTP
functionality.
For more details about new features and potential incompatibilities see the readme