Some highlights for 20.1:
- crypto, public_key: Extend crypto and public_key functions sign and
verify with:
- support for RSASSA-PS padding for signatures and for saltlength
setting
- X9.31 RSA padding.
- sha, sha224, sha256, sha384, and sha512 for dss signatures as
mentioned in NIST SP 800-57 Part 1.
- ripemd160 to be used for rsa signatures.
- A new tuple in crypto:supports/0 reports supported MAC algorithms.
- diameter:
- Add service option decode_format to allow incoming messages to be
decoded into maps instead of records.
- Decode performance has been improved.
- Add service/transport option avp_dictionaries to give better
support for dictionaries only defining AVPs.
- erts: Upgraded the ERTS internal PCRE library from version 8.40 to
version 8.41.
- erts, kernel, tools: Profiling with lock counting can now be fully
toggled at runtime in the lock counting emulator (-emu_type lcnt).
- erts: The zlib module has been refactored and all its operations
will now yield appropriately, allowing them to be used freely in
concurrent applications.
- erts, tools: Add erlang:iolist_to_iovec/1, which converts an
iolist() to an erlang:iovec(), which is suitable for use with
enif_inspect_iovec().
- erts: Add new nif API functions for managing an I/O Queue.
- observer/crashdump_viewer:
- Reading of crash dumps with many binaries is optimized.
- A progress bar is shown when the detail view for a process is
opened.
- The cdv script now sets ERL_CRASH_DUMP_SECONDS=0 to avoid
generating a new crash dump from the node running the Crashdump
Viewer.
- observer: Add system statistics and limits to frontpage in observer.
- public_key, ssl**: Improved error propagation and reports
- ssh: A new option modify_algorithms is implemented. It enables
specifying changes on the default algorithms list.
- tools/xref: The predefined Xref analysis locals_not_used now
understands the -on_load() attribute and does not report unused
functions.
- tools/fprof: When sampling multiple processes and analyzing with
totals set to true, the output now sums together all caller and
callee entries which concerns the same function.
Potential Incompatibilities
---------------------------
- ERTS:
- The non SMP Erlang VM is deprecated and not built by default
- Remove deprecated erlang:hash/2
- erlang:statistics/1 with scheduler_wall_time now also includes
info about dirty CPU schedulers.
- The new purge strategy introduced in OTP 19.1 is mandatory and
slightly incompatible for processes holding funs
- The NIF library reload is not supported anymore.
- Atoms can now contain arbitrary unicode characters which means
that the DFLAG_UTF8_ATOMS capability in the distribution protocol
must be supported if an OTP 20 node should accept the connection
with another node or library.
- Asn1: Deprecated module and functions removed (asn1rt,
asn1ct:encode/3 and decode/3)
- Ssh: client only option in a call to start a daemon will now fail
Highlights
----------
- Erts:
- Dirty schedulers enabled and supported on VM with SMP support.
- support for "dirty" BIFs and "dirty" GC.
- erlang:garbage_collect/2 for control of minor or major GC
- Erlang literals are no longer copied when sending messages.
- Improved performance for large ETS tables, >256 entries (except
ordered_set)
- erlang:system_info/1 atom_count and atom_limit
- Reduced memory pressure by converting sub-binaries to
heap-binaries during GC
- enif_select, map an external event to message
- Improvements of timers internally in the VM resulting in reduced
memory consumption and more efficient administration for timers
- Compiler:
- Code generation for complicated guards is improved.
- Warnings for repeated identical map keys. #{'a'=>1, 'b'=>2,
'a'=>3} will warn for the repeated key a.
- By default there is now a warning when export_all is used. Can be
disabled
- Pattern matching for maps is optimized
- New option deterministic to omit path to source + options info the
BEAM file.
- Atoms may now contain arbitrary unicode characters.
- compile:file/2 has an option to include extra chunks in the BEAM
file.
- Misc other applications
- Significantly updated string module with unicode support and many
new functions
- crypto now supports OpenSSL 1.1
- Unnamed ets tables optimized
- gen_fsm is deprecated and replaced by gen_statem
- A new event manager to handle a subset of OS signals in Erlang
- Optimized sets add_element, del_element and union
- Added rand:jump/0-1
- When a gen_server crashes, the stacktrace for the client will be
printed to facilitate debugging.
- take/2 has been added to dict, orddict, and gb_trees.
- take_any/2 has been added to gb_trees
- erl_tar support for long path names and new file formats
- asn1: the new maps option changes the representation of SEQUENCE
to be maps instead of records
- A TLS client will by default call
public_key:pkix_verify_hostname/2 to verify the hostname
- ssl: DTLS documented in the API, experimental
- ssh: improving security, removing and adding algorithms
- New math:fmod/2
Some highlights for 19.3:
- crypto, ssh: The implementation of the key exchange algorithms
diffie-hellman-group-exchange-sha* are optimized, up to a factor of 11
for the slowest ( = biggest and safest) group size.
- dialyzer: The peak memory consumption is reduced. Analyzing modules
with binary construction with huge strings is now much faster.
- erts: A received SIGTERM signal to beam will generate a 'stop' message
to the init process and terminate the Erlang VM nicely. This is
equivalent to calling init:stop/0.
- kernel: The functions in the 'file' module that take a list of paths
(e.g. file:path_consult/2) will now continue to search in the path if
the path contains something that is not a directory.
- public_key: New function pkix_verify_hostname/2,3 Implements
certificate hostname checking. See the manual and RFC 6125.
- public_key, ssh: The ssh host key fingerprint generation now also
takes a list of algorithms and returns a list of corresponding
fingerprints. See public_key:ssh_hostkey_fingerprint/2 and the option
silently_accept_hosts in ssh:connect.
- ssl: Move PEM cache to a dedicated process, to avoid making the SSL
manager process a bottleneck. This improves scalability of TLS
connections.
- stdlib: filename:safe_relative_path/1 to sanitize a relative path has
been added.
Full release notes:
http://erlang.org/download/otp_src_19.3.readme
Erlang/OTP 19.2 is the second service release for the 19 major release.
The service release contains mostly bug fixes and characteristics
improvements.
Some highlights for 19.2
* STDLIB: The new behaviour gen_statem has been improved with 3 new
features: the possibility to use old style non-proxy timeouts
for gen_statem:call/2,3, state entry code, and state
timeouts. These are backwards compatible. Minor code and
documentation improvements has been performed including a
borderline semantics correction of timeout zero handling.
* SSL: Experimental version of DTLS. It is runnable but not complete
and cannot be considered reliable for production usage. To use
DTLS add the option {protocol, dtls} to ssl:connect and ssl:listen.
* SSH: Extended the option silently_accept_hosts for ssh:connect to
make it possible for the client to check the SSH host key
fingerprint string. Se the reference manual for SSH.
* ~40 contributions since the previous service release OTP 19.1
You can find the README and the full listing of changes for this
service release at
http://www.erlang.org/download/otp_src_19.2.readme
Some highlights of the release are:
- erts: Improved dirty scheduler support. A purge of a module will
- not have to wait for completion of all ongoing dirty NIF calls.
- erts: Improved accuracy of timeouts on MacOS X.
- kernel: Add net_kernel:setopts/2 and net_kernel:getopts/2 to
- control options for distribution sockets in runtime.
- asn1: Compiling multiple ASN.1 modules in the same directory with
- parallel make (make -j) should now be safe.
- httpd: support for PUT and DELETE in mod_esi
- ~30 contributions since 19.0
You can find the Release Notes with more detailed info at
http://www.erlang.org/download/otp_src_19.1.readme
- compiler, stdlib:
- New preprocessor macros ?FUNCTION_NAME, ?FUNCTION_ARITY
- New preprocessor directives -error(Term) and -warning(Term) to
cause a compilation error or warning, respectively.
- gen_statem a new state machine behavior
- mnesia_ext: plugin of external storage solutions to mnesia
- crypto: uses EVP interface in OpenSSL resulting in generally
better performance and support for HW acceleration
- ssh: performance improvements, uses the new gen_statem behavior
- ssl: enhanced error log messages
- dialyzer: the support for maps is very much extended both the
type specification syntax and the type analysis.
- erts:
- erlang:open_port(spawn, ...) 3-5 times faster
- tracing, extensive improvements (scalability, speed, match
specifications on send/receive, support for lttng, ...)
- dirty schedulers improved
- per process configurable handling of message_queue
- fast loading of multiple modules
- max_heap_size process flag
- erts/kernel: Experimental support for Unix Domain Sockets
Full changelog:
http://erlang.org/download/otp_src_19.0.readme
Some highlights of the release are:
- New statistics info about runnable and active processes & ports.
- Time warp improvements: dbg:p/2 and erlang:trace/3 with
monotonic_timestamp | strict_monotonic_timestamp.
- Introduced a validation callback for heart.
- The module overload in sasl has been deprecated.
- ~90 contributions since 18.2
Full release notes:
http://erlang.org/download/otp_src_18.3.readme
erlang 18.2.1
Due to a bug in the handling of paths on windows none of the following
would work with paths containing a space:
- ct_run
- dialyzer
- erlc
- escript
- typer
This also contains a fix for HiPE enabled emulator for FreeBSD.
erlang 18.2
- ssl: Add configurable upper limit for session cache.
- erts: Add function enif_getenv to read OS environment variables in
a portable way from NIFs.
- kernel: Add {line_delim, byte()} option to inet:setopts/2 and
decode_packet/3
- ssh: The 'ecdsa-sha2-nistp256', 'ecdsa-sha2-nistp384' and
'ecdsa-sha2-nistp521' signature algorithms for ssh are implemented.
See RFC 5656.
- ssh: The ssh:daemon option dh_gex_groups is extended to read a user
provided ssh moduli file with generator-modulus pairs. The file is
in openssh format.
- Thanks to 41 different contributors!
Some highlights of the release are:
- ssl: Add possibility to downgrade an SSL/TLS connection to a tcp
connection, and give back the socket control to a user process.
- ssh: The following new key exchange algorithms are implemented:
'ecdh-sha2-nistp256', 'ecdh-sha2-nistp384', 'ecdh-sha2-nistp521',
'diffie-hellman-group14-sha1', 'diffie-hellman-group-exchange-sha1'
and 'diffie-hellman-group-exchange-sha256'. This raises the
security level considerably.
- kernel,stdlib,sasl: A mechanism for limiting the amount of text
that the built-in error logger events will produce has been
introduced. It is useful for limiting both the size of log files
and the CPU time used to produce them.
Full release notes:
http://www.erlang.org/download/otp_src_18.1.readme
- Starting from 18.0 Erlang/OTP is released under the APL 2.0
- erts: The time functionality has been extended. This includes a new API
for time, as well as "time warp" modes which alters the behavior when
system time changes. You are strongly encouraged to use the new API
instead of the old API based on erlang:now/0. erlang:now/0 has been
deprecated since it is a scalability bottleneck.
- erts: Beside the API changes and time warp modes a lot of scalability
and performance improvements regarding time management has been made
- erts: The previously introduced "eager check I/O" feature is now enabled
by default.
- erts/compiler: enhanced support for maps. Big maps new uses a HAMT
(Hash Array Mapped Trie) representation internally which makes them more
efficient. There is now also support for variables as map keys.
- dialyzer: The -dialyzer() attribute can be used for suppressing warnings
in a module by specifying functions or warning options.
- ssl: Remove default support for SSL-3.0 and added padding check
for TLS-1.0 due to the Poodle vulnerability.
- ssl: Remove default support for RC4 cipher suites, as they are consider
too weak.
- stdlib: Allow maps for supervisor flags and child specs
- stdlib: New functions in ets:
- take/2. Works the same as ets:delete/2 but
also returns the deleted object(s).
- ets:update_counter/4 with a default object as
argument
Full changelog:
http://www.erlang.org/download/otp_src_18.0.readme
erlang-17.5
================================
Highlights:
- ERTS: Added command line argument option for setting the initial size
of process dictionaries.
- Diameter: configurable incoming_max len and string_decode for diameter
messages
- Bugfixes and minor small features in applications such as compiler,
common_test, crypto, debugger, eldap, erts, hipe, inets, ssh, ssl,...
Full changelog:
http://www.erlang.org/download/otp_src_17.5.readme
erlang-17.4
================================
Highlights:
- eldap: Nearly all TCP options are possible to give in the eldap:open/2 call.
- ssh: Added API functions ptty_alloc/3 and ptty_alloc/4, to allocate
a pseudo tty.
- ssl: Handle servers that may send an empty SNI extension to the client.
Full changelog:
http://www.erlang.org/download/otp_src_17.4.readme
erlang-17.3
================================
Highlights:
- erts: Introduced enif_schedule_nif() which allows a long running NIF
to be broken into separate NIF invocations without the help of a wrapper
function written in Erlang
- common_test: Experimental support for running Quickcheck and PropEr tests
from common_test suites is added. Examples of usage in the suites for
the ssh and inets applications
- Bugfixes and minor new features in applications such as asn1, erts, kernel,
stdlib, diameter, ssh, mnesia, ssl, jinterface
Full changelog:
http://www.erlang.org/download/otp_src_17.3.readme
erlang-17.1
================================
Highlights:
- crypto: Add aes_cfb8 cypher to crypto:block_encrypt and block_decrypt.
- diameter: Add result code counters for CEA, DWA, and DPA.
- erts: The following built in functions in the erlang and binary modules
now bump an appropriate amount of reductions and yield when
out of reductions:
binary_to_list/1, binary_to_list/3, bitstring_to_list/1,
list_to_binary/1, iolist_to_binary/1, list_to_bitstring/1,
binary:list_to_bin/1
- hipe: Handle Maps instructions get_map_elements, put_map_assoc,
put_map_exact in the HiPE native code compiler.
- mnesia: The time for inserting locks for a transaction with large
number of locks is reduced significantly.
- ssh: Option max_sessions added to ssh:daemon/{2,3}.
- stdlib: Add maps:get/3 to maps module. The function will return the
supplied default value if the key does not exist in the map.
Full changelog:
http://www.erlang.org/download/otp_src_17.1.readme
erlang-17.0
================================
Highlights:
- Erlang/OTP has been ported to the realtime operating system OSE.
- Maps, a new dictionary data type (experimental)
- A more natural mapping from ASN.1 OCTET STRING and BIT STRING to
Erlang types, and other ASN.1 improvements and optimizations
- The {active, N} socket option for TCP, UDP, and SCTP
- A new (optional) scheduler utilization balancing mechanism
- Migration of memory carriers has been enabled by default on all
ERTS internal memory allocators
- Increased garbage collection tenure rate
- Experimental "dirty schedulers" functionality
- Funs can now be given names
- Miscellaneous unicode support enhancements
- A new version scheme for OTP its applications has been introduced
Full changelog:
http://www.erlang.org/download/otp_src_17.0.readme
erlang 16.1.3.1 (R16B03-1)
================================
Highlights:
- The ODBC application was missing in the prebuilt Windows installers
- 3 corrections in the SSL application:
- Add missing validation of the server_name_indication option and test
for its explicit use.
- Elliptic curve selection in server mode now properly selects a curve
suggested by the client, if possible.
- The server did not indicate support for secure renegotiation during
TLS extension handling.
- In the syntax tools application a bug was introduced which broke
reverting of local funs. This is now corrected (thanks to Anthony Ramine)
- wx - Solved a problem which caused the debugger to crash when closing
a window. Fixed static linking on Mac.
- xmerl - Fixed a problem in the SAX-parser when the header of
the next document was appearing in the buffer when using
the xmerl_sax_parser:stream/2 function.
Full changelog:
http://www.erlang.org/download/otp_src_R16B03-1.readme
erlang-16.1.3 (R16B03)
================================
Highlights:
- A new memory allocation feature called "super carrier" has been introduced.
It can for example be used for pre-allocation of all memory that the
runtime system should be able to use. It is enabled by passing the +MMscs
(size in MB) command line argument. For more information see
the documentation of the +MMsco, +MMscrfsd, +MMscrpm, +MMscs, +MMusac, and,
+Mlpm command line arguments in the erts_alloc(3) documentation.
- The ldap client eldap now supports the start_tls operation. This upgrades
an existing tcp connection to encryption using tls,
see eldap:start_tls/2 and /3.
- The ftp client (inets application) now supports ftp over tls (ftps).
Full changelog:
http://www.erlang.org/download/otp_src_R16B03.readme
R16B02 is the second maintenance release for the R16B major release.
You can find the README file for the release at
http://www.erlang.org/download/otp_src_R16B02.readme
R16B01 is the first maintenance release for the R16B major release.
You can find the README file for the release at
http://www.erlang.org/download/otp_src_R16B01.readme
Highlights for R16B01:
OTP-10279 == erts ==
Support for migration of memory carriers between memory
allocator instances has been introduced.
By default this feature is not enabled and do not effect the
characteristics of the system. When enabled it has the
following impact on the characteristics of the system:
-- Reduced memory footprint when the memory load is unevenly
distributed between scheduler specific allocator instances.
-- Depending on the default allocaton strategy used on a
specific allocator there might or might not be a slight
performance loss.
-- When enabled on the fix_alloc allocator, a different
strategy for management of fix blocks will be used.
-- The information returned from
erlang:system_info({allocator, A}), and
erlang:system_info({allocator_sizes, A}) will be slightly
different when this feature has been enabled. An mbcs_pool
tuple will be present giving information about abandoned
carriers, and in the fix_alloc case no fix_types tuple will
be present.
For more information, see the documentation of the +M<S>acul
command line argument.
OTP-11009 == ssl public_key crypto common_test dialyzer ssh stdlib snmp
inets ==
Integrate elliptic curve contribution from Andreas Schultz
In order to be able to support elliptic curve cipher suites
in SSL/TLS, additions to handle elliptic curve infrastructure
has been added to public_key and crypto.
This also has resulted in a rewrite of the crypto API to gain
consistency and remove unnecessary overhead. All OTP
applications using crypto has been updated to use the new
API.
Impact: Elliptic curve cryptography (ECC) offers equivalent
security with smaller key sizes than other public key
algorithms. Smaller key sizes result in savings for power,
memory, bandwidth, and computational cost that make ECC
especially attractive for constrained environments.
OTP-11159 == erts ==
Lift static limitation (FD_SETSIZE) for file descriptors on
Mac OS X. (Thanks to Anthony Ramine)
R16B is a major new release of Erlang/OTP.
Detailed information on changes can be fetched at
http://www.erlang.org/download/otp_src_R16B.readme
--- HIGHLIGHTS ----------------------------------------------------------
OTP-7786 == ssh ==
Added User Guide for the SSH application
OTP-9892 == erts ==
Process optimizations. The most notable:
-- New internal process table implementation allowing for
both parallel reads as well as writes. Especially read
operations have become really cheap. This reduce contention
in various situations. For example when, spawning processes,
terminating processes, sending messages, etc.
-- Optimizations of run queue management reducing contention.
-- Optimizations of process state changes reducing
contention.
These changes imply changes of the characteristics the
system. Most notable: changed timing in the system.
OTP-9974 == erts ==
Non-blocking code loading. Earlier when an Erlang module was
loaded, all other execution in the VM were halted while the
load operation was carried out in single threaded mode. Now
modules are loaded without blocking the VM. Processes may
continue executing undisturbed in parallel during the entire
load operation. The load operation is completed by making the
loaded code visible to all processes in a consistent way with
one single atomic instruction. Non-blocking code loading will
improve realtime characteristics when modules are
loaded/upgraded on a running SMP system.
OTP-10256 == inets ==
httpc: The HTTP client now supports HTTPS through proxies
OTP-10336 == erts ==
Major port improvements. The most notable:
-- New internal port table implementation allowing for both
parallel reads as well as writes. Especially read operations
have become really cheap.This reduce contention in various
situations. For example when, creating ports, terminating
ports, etc.
-- Dynamic allocation of port structures. This allow for a
much larger maximum amount of ports allowed as a default. The
previous default of 1024 has been raised to 65536. Maximum
amount of ports can be set using the +Q command line flag of
erl(1). The previously used environment variable
ERL_MAX_PORTS has been deprecated and scheduled for removal
in OTP-R17.
-- Major rewrite of scheduling of port tasks. Major benefits
of the rewrite are reduced contention on run queue locks, and
reduced amount of memory allocation operations needed. The
rewrite was also necessary in order to make it possible to
schedule signals from processes to ports.
-- Improved internal thread progress functionality for easy
management of unmanaged threads. This improvement was
necessary for the rewrite of the port task scheduling.
-- Rewrite of all process to port signal implementations in
order to make it possible to schedule those operations. All
port operations can now be scheduled which allows for reduced
lock contention on the port lock as well as truly
asynchronous communication with ports.
-- Optimized lookup of port handles from drivers.
-- Optimized driver lookup when creating ports.
-- Preemptable erlang:ports/0 BIF.
-- Improving responsiveness by bumping reductions for a
process calling a driver callback directly.
These changes imply changes of the characteristics of the
system. The most notable:
-- Order of signal delivery -- The previous implementation of
the VM has delivered signals from processes to ports in a
synchronous stricter fashion than required by the language.
As of ERTS version 5.10, signals are truly asynchronously
delivered. The order of signal delivery still adheres to the
requirements of the language, but only to the requirements.
That is, some signal sequences that previously always were
delivered in one specific order may now from time to time be
delivered in different orders. This may cause Erlang programs
that have made false assumptions about signal delivery order
to fail even though they previously succeeded. For more
information about signal ordering guarantees, see the chapter
on communication in the ERTS user's guide. The +n command
line flag of erl(1) can be helpful when trying to find
signaling order bugs in Erlang code that have been exposed by
these changes.
-- Latency of signals sent from processes to ports -- Signals
from processes to ports where previously always delivered
immediately. This kept latency for such communication to a
minimum, but it could cause lock contention which was very
expensive for the system as a whole. In order to keep this
latency low also in the future, most signals from processes
to ports are by default still delivered immediately as long
as no conflicts occur. Such conflicts include not being able
to acquire the port lock, but also include other conflicts.
When a conflict occur, the signal will be scheduled for
delivery at a later time. A scheduled signal delivery may
cause a higher latency for this specific communication, but
improves the overall performance of the system since it
reduce lock contention between schedulers. The default
behavior of only scheduling delivery of these signals on
conflict can be changed by passing the +spp command line flag
to erl(1). The behavior can also be changed on port basis
using the parallelism option of the open_port/2 BIF.
-- Execution time of the erlang:ports/0 BIF -- Since
erlang:ports/0 now can be preempted, the responsiveness of
the system as a whole has been improved. A call to
erlang:ports/0 may, however, take a much longer time to
complete than before. How much longer time heavily depends on
the system load.
-- Reduction cost of calling driver callbacks -- Calling a
driver callback is quite costly. This was previously not
reflected in reduction cost at all. Since the reduction cost
now has increased, a process performing lots of direct driver
calls will be scheduled out more frequently than before.
Potential incompatibilities:
-- driver_send_term() has been deprecated and has been
scheduled for removal in OTP-R17. Replace usage of
driver_send_term() with usage of erl_drv_send_term().
-- driver_output_term() has been deprecated and has been
scheduled for removal in OTP-R17. Replace usage of
driver_output_term() with usage of erl_drv_output_term().
-- The new function erl_drv_busy_msgq_limits() has been added
in order to able to control management of port queues.
The driver API version has been bumped to 2.1 from 2.0 due to
the above changes in the driver API.
OTP-10410 == asn1 ==
The options for the ASN.1 compiler has been drastically
simplified. The backend is chosen by using ber, per, or uper.
The options optimize, nif, and driver are no longer needed.
The old options will still work, but will issue a warning.
Another change is that generated encode/2 function will
always return a binary (some backends used to return an
iolist).
OTP-10588 == asn1 ==
The ASN.1 compiler will now always include necessary run-time
functions in the generated Erlang modules (except for
asn1rt_nif which is still neeeded). If the option 'inline' is
used the ASN.1 compiler will generate a warning. But if
'{inline,OutputFile}' is use, the ASN.1 compiler will refuse
to compile the file. (Use a .set.asn file if you need to
remove the output file.)
The 'BIT STRING' type will now be decoded as Erlang
bitstrings by default. Use the new legacy_bit_string option
to encode as lists of ones and zeroes. (The
compact_bit_string option still works as before.)
Open types are now always returned as binaries (when there is
no information allowing them to be decoded).
--- POTENTIAL INCOMPATIBILITIES -----------------------------------------
OTP-9052 == common_test ==
Removed depricated run_test program, use ct_run instead.
OTP-9881 == common_test ==
It is now possible to let a test specification include other
test specifications. Included specs can either be joined with
the source spec (and all other joined specs), resulting in
one single test run, or they can be executed in separate test
runs. Also, a start flag/option, join_specs, has been
introduced, to be used in combination with the spec option.
With join_specs, Common Test can be told to either join
multiple test specifications, or run them separately. Without
join_specs, the latter behaviour is default. Note that this
is a change compared to earlier versions of Common Test,
where specifications could only be joined. More information
can be found in the Running Tests chapter in the User's Guide
(see the Test Specifications section).
OTP-10117 == inviso ==
The inviso application has been removed.
OTP-10170 == erts pman ==
Tuple funs (deprecated in R15B) are no longer supported.
OTP-10195 == edoc ==
Since EDoc 0.7.7 (R14B02) separate values of union types can
be annotated. However, the parser has hitherto chosen not to
add the necessary parentheses due to backwards compatibility.
From this release on code traversing the output of
edoc_parser needs to take care of parentheses around separate
values of union types. Examples of such code are layout
modules and doclet modules.
OTP-10336 == erts ==
Major port improvements. The most notable:
-- New internal port table implementation allowing for both
parallel reads as well as writes. Especially read operations
have become really cheap.This reduce contention in various
situations. For example when, creating ports, terminating
ports, etc.
-- Dynamic allocation of port structures. This allow for a
much larger maximum amount of ports allowed as a default. The
previous default of 1024 has been raised to 65536. Maximum
amount of ports can be set using the +Q command line flag of
erl(1). The previously used environment variable
ERL_MAX_PORTS has been deprecated and scheduled for removal
in OTP-R17.
-- Major rewrite of scheduling of port tasks. Major benefits
of the rewrite are reduced contention on run queue locks, and
reduced amount of memory allocation operations needed. The
rewrite was also necessary in order to make it possible to
schedule signals from processes to ports.
-- Improved internal thread progress functionality for easy
management of unmanaged threads. This improvement was
necessary for the rewrite of the port task scheduling.
-- Rewrite of all process to port signal implementations in
order to make it possible to schedule those operations. All
port operations can now be scheduled which allows for reduced
lock contention on the port lock as well as truly
asynchronous communication with ports.
-- Optimized lookup of port handles from drivers.
-- Optimized driver lookup when creating ports.
-- Preemptable erlang:ports/0 BIF.
-- Improving responsiveness by bumping reductions for a
process calling a driver callback directly.
These changes imply changes of the characteristics of the
system. The most notable:
-- Order of signal delivery -- The previous implementation of
the VM has delivered signals from processes to ports in a
synchronous stricter fashion than required by the language.
As of ERTS version 5.10, signals are truly asynchronously
delivered. The order of signal delivery still adheres to the
requirements of the language, but only to the requirements.
That is, some signal sequences that previously always were
delivered in one specific order may now from time to time be
delivered in different orders. This may cause Erlang programs
that have made false assumptions about signal delivery order
to fail even though they previously succeeded. For more
information about signal ordering guarantees, see the chapter
on communication in the ERTS user's guide. The +n command
line flag of erl(1) can be helpful when trying to find
signaling order bugs in Erlang code that have been exposed by
these changes.
-- Latency of signals sent from processes to ports -- Signals
from processes to ports where previously always delivered
immediately. This kept latency for such communication to a
minimum, but it could cause lock contention which was very
expensive for the system as a whole. In order to keep this
latency low also in the future, most signals from processes
to ports are by default still delivered immediately as long
as no conflicts occur. Such conflicts include not being able
to acquire the port lock, but also include other conflicts.
When a conflict occur, the signal will be scheduled for
delivery at a later time. A scheduled signal delivery may
cause a higher latency for this specific communication, but
improves the overall performance of the system since it
reduce lock contention between schedulers. The default
behavior of only scheduling delivery of these signals on
conflict can be changed by passing the +spp command line flag
to erl(1). The behavior can also be changed on port basis
using the parallelism option of the open_port/2 BIF.
-- Execution time of the erlang:ports/0 BIF -- Since
erlang:ports/0 now can be preempted, the responsiveness of
the system as a whole has been improved. A call to
erlang:ports/0 may, however, take a much longer time to
complete than before. How much longer time heavily depends on
the system load.
-- Reduction cost of calling driver callbacks -- Calling a
driver callback is quite costly. This was previously not
reflected in reduction cost at all. Since the reduction cost
now has increased, a process performing lots of direct driver
calls will be scheduled out more frequently than before.
Potential incompatibilities:
-- driver_send_term() has been deprecated and has been
scheduled for removal in OTP-R17. Replace usage of
driver_send_term() with usage of erl_drv_send_term().
-- driver_output_term() has been deprecated and has been
scheduled for removal in OTP-R17. Replace usage of
driver_output_term() with usage of erl_drv_output_term().
-- The new function erl_drv_busy_msgq_limits() has been added
in order to able to control management of port queues.
The driver API version has been bumped to 2.1 from 2.0 due to
the above changes in the driver API.
OTP-10410 == asn1 ==
The options for the ASN.1 compiler has been drastically
simplified. The backend is chosen by using ber, per, or uper.
The options optimize, nif, and driver are no longer needed.
The old options will still work, but will issue a warning.
Another change is that generated encode/2 function will
always return a binary (some backends used to return an
iolist).
OTP-10417 == kernel sasl ==
It is no longer possible to have {Mod,Vsn} in the 'modules'
list in a .app file.
This was earlier possible, although never documented in the
.app file reference manual. It was however visible in the
documentation of application:load/[1,2], where the same term
as in a .app file can be used as the first argument.
The possibility has been removed since the Vsn part was never
used.
OTP-10451 == ssl ==
Remove filter mechanisms that made error messages backwards
compatible with old ssl but hid information about what
actually happened.
This does not break the documented API however other reason
terms may be returned, so code that matches on the reason
part of {error, Reason} may fail.
OTP-10490 == stdlib ==
If a child process fails in its start function, then the
error reason was earlier only reported as an error report
from the error_handler, and supervisor:start_link would only
return {error,shutdown}. This has been changed so the
supervisor will now return {error,{shutdown,Reason}}, where
Reason identifies the failing child and its error reason.
(Thanks to Tomas Pihl)
OTP-10523 == tools ==
A new function, cover:flush(Nodes), is added which will fetch
data from remote nodes without stopping cover on those nodes.
This is used by test_server and common_test when it is safe
to assume that the node will be terminated after the test
anyway. The purpose is to avoid processes crashing when
re-loading the original beam if the processes is still
running old code.
Remote nodes will now continue to count code coverage if the
connection to the main node is broken. Earlier, a broken
connection would cause the cover_server on the remote node to
die and thus any still cover compiled modules would cause
process crash when trying to insert cover data in ets tables
that used to exist on the cover_server. The new functionality
also involves synchronization with the main node if the nodes
are reconnected.
OTP-10588 == asn1 ==
The ASN.1 compiler will now always include necessary run-time
functions in the generated Erlang modules (except for
asn1rt_nif which is still neeeded). If the option 'inline' is
used the ASN.1 compiler will generate a warning. But if
'{inline,OutputFile}' is use, the ASN.1 compiler will refuse
to compile the file. (Use a .set.asn file if you need to
remove the output file.)
The 'BIT STRING' type will now be decoded as Erlang
bitstrings by default. Use the new legacy_bit_string option
to encode as lists of ones and zeroes. (The
compact_bit_string option still works as before.)
Open types are now always returned as binaries (when there is
no information allowing them to be decoded).
OTP-10613 == ssl ==
Removed deprecated function ssl:pid/0, it has been pointless
since R14 but has been keep for backwards compatibility.
OTP-10633 == erts ==
Erlang specification 4.7.3 defines max tuple size to 65535
elements It is now enforced to no more than 16777215 elements
(arity 24 bits)
Previous edge cases (28 bits) were not validated and could
cause undefined behaviour.
OTP-10647 == erts ==
The previous default of a maximum of 32768 simultaneous
processes has been raised to 262144. This value can be
changed using the the +P command line flag of erl(1). Note
that the value passed now is considered as a hint, and that
actual value chosen in most cases will be a power of two.
OTP-10812 == stdlib ==
filelib:wildcard("some/relative/path/*.beam", Path) would
fail to match any file. That is, filelib:wildcard/2 would not
work if the first component of the pattern did not contain
any wildcard characters. (A previous attempt to fix the
problem in R15B02 seems to have made matters worse.)
(Thanks to Samuel Rivas and Tuncer Ayaz.)
There is also an incompatible change to the Path argument. It
is no longer allowed to be a binary.
OTP-10872 == erts ==
As of ERTS-5.10/OTP-R16A node names passed in the EPMD
protocol are required to be encoded in UTF-8. Since EPMD
previously accepted latin1 encoded node names this is an
incompatibility. However, since Erlang nodes always have
required characters in node names to be 7-bit ASCII
characters (and still do require this), this incompatibility
should not effect anyone using EPMD as an Erlang Port Mapper
Daemon.
Changes in R15B03-1
After the release of R15B03 a very unfortunate bug in ssl:ssl_accept/2
(accept with timeout) was detected. This bug will have negative impact
on a number of popular http servers and server frameworks written in
Erlang.
The differences from R15B03 are in ssl-5.1.2 and erts-5.9.3.1.
Full log at http://www.erlang.org/download/otp_src_R15B03-1.readme
Changes in R15B03
Mostly bug fixes and small improvements.
Full log at http://www.erlang.org/download/otp_src_R15B03.readme
Changes in R15B02
Highlights
OTP-8871 == ssl ==
Experimental support for TLS 1.1 is now available, will be
officially supported from OTP-R16. Thanks to Andreas Schultz
for implementing the first version.
OTP-8872 == ssl ==
Experimental support for TLS 1.2 is now available, will be
officially supported from OTP-R16. Thanks to Andreas Schultz
for implementing the first version.
OTP-10113 == ssl ==
Removed some bottlenecks increasing the applications
parallelism especially for the client side.
Full log at http://www.erlang.org/download/otp_src_R15B02.readme
Changes in Erlang/OTP R15B01
Highlights:
* Dialyzer: The type analysis tool Dialyzer is optimized to be
generally faster. - It can now also run in parallel (default)
on SMP systems and by this perform the analysis significantly
faster (Thanks to Stavros Aronis and Kostis Sagonas)
* The SSL application now has experimental support for the
TLS 1.1 and 1.2 standards as well (Thanks to Andreas Schultz).
* CommonTest: It is now possible to sort the generated html tables.
A Netconf client (ct_netconf) which support basic netconf over
ssh is added
* Diameter: Statistics counters related to Diameter messages
can now be retrieved by calling the diameter:service_info/2
function.
* Various smaller optimizations in the Erlang VM
* This release also contains 66 contributions from users
outside the Ericsson team
Presumably fixes PR pkg/46297
Changes in Erlang/OTP R15B01
Highlights:
* Added erlang:statistics(scheduler_wall_time) to ensure
correct determination of scheduler utilization. Measuring
scheduler utilization is strongly preferred over CPU
utilization, since CPU utilization gives very poor
indications of actual scheduler/vm usage.
* Changed ssh implementation to use the public_key application
for all public key handling. This is also a first step for
enabling a callback API for supplying public keys and
handling keys protected with password phrases. Additionally
the test suites where improved so that they do not copy the
users keys to test server directories as this is a security
liability. Also ipv6 and file access issues found in the
process has been fixed.
* When an escript ends now all printout to standard output and
standard error gets out on the terminal. This bug has been
corrected by changing the behaviour of erlang:halt/0,1,
which should fix the same problem for other escript-like
applications, i.e. that data stored in the output port
driver buffers got lost when printing on a TTY and exiting
through erlang:halt/0,1. The BIF:s erlang:halt/0,1 has
gotten improved semantics and there is a new BIF
erlang:halt/2 to accomplish something like the old
semantics. See the documentation.
* The DTrace source patch from Scott Lystig Fritchie is
integrated in the source tree. Using an emulator with dtrace
probe is still not supported for production use, but may be
a valuable debugging tool.
* Added Torbjörn Törnkvists LDAP client as a new application
called eldap.
* Added options for the ssh client to support user keys files
that are password protected.
Changes in Erlang/OTP R15B
Highlights:
* Line number and filename information are now included in
exception backtraces. This information will be
pretty-printed in the shell and used in crash reports etc.
In practice it will be much easier to find where something
failed.
* The driver interface has been changed to enable 64-bit aware
drivers. Most importantly the return types for ErlDrvEntry
callbacks 'call' and 'control' has been changed which
require drivers to be changed.
* New in this release is the support for 64 bit Windows.
The self extracting installer can be found here.
* CommonTest hooks are now in a final supported version.
* There is a new GUI tool in the observer application which
integrates pman, etop, appmon and tv into one tool. The tool
does also contain functions for activating tracing in an easy way.
* The Erlang distribution can now be run over the new SSL implementation.
Changes in Erlang/OTP R15A
Notable changes:
OTP-9468 'Line numbers in exceptions'
OTP-9451 'Parallel make'
OTP-4779 A new GUI for Observer. Integrating pman, etop and tv into
observer with tracing facilities.
OTP-7775 A number of memory allocation optimizations have been
implemented. Most optimizations reduce contention caused by
synchronization between threads during allocation and
deallocation of memory. Most notably:
Synchronization of memory management in scheduler
specific allocator instances has been rewritten to
use lock-free synchronization.
Synchronization of memory management in scheduler
specific pre-allocators has been rewritten to use
lock-free synchronization.
The 'mseg_alloc' memory segment allocator now use
scheduler specific instances instead of one
instance. Apart from reducing contention this also
ensures that memory allocators always create memory
segments on the local NUMA node on a NUMA system.
OTP-9632 An ERTS internal, generic, many to one, lock-free
queue for communication between threads has been
introduced. The many to one scenario is very common in
ERTS, so it can be used in a lot of places in the
future. Currently it is used by scheduling of certain
jobs, and the async thread pool, but more uses are
planned for the future.
Drivers using the driver_async functionality are not
automatically locked to the system anymore, and can be
unloaded as any dynamically linked in driver.
Scheduling of ready async jobs is now also interleaved
in between other jobs. Previously all ready async jobs
were performed at once.
OTP-9631 The ERTS internal system block functionality has been
replaced by new functionality for blocking the system.
The old system block functionality had contention
issues and complexity issues. The new functionality
piggy-backs on thread progress tracking functionality
needed by newly introduced lock-free synchronization
in the runtime system. When the functionality for
blocking the system isn't used, there is more or less
no overhead at all. This since the functionality for
tracking thread progress is there and needed anyway.
This release is mainly a stabilization of the R14B03 release (but as
usual there are some new functionality as well).
One pkgsrc change: add flex to USE_TOOLS, so that megaco_flex_scanner_drv
gets built on all SunOS flavors.
Read full announcement at
http://www.erlang.org/download/otp_src_R14B04.readme
Highlights:
- Initial release of the diameter application.
- Strengthened random number generation.
- Some fixes for bugs that caused crashes.
Read full announcement at
http://www.erlang.org/download/otp_src_R14B03.readme
Highlights composed by Matthew Sporleder.
Changes in R14B02 (http://www.erlang.org/download/otp_src_R14B02.readme)
- It is now possible to use Erlang specifications and types
in EDoc documentation
- All tests in Erlang/OTP have been converted to be run with
Common Test as the backend instead of Test Server.
- From this release, the previously experimental halfword
emulator is now official
- Dependency generation for Makefiles has been added to the
compiler and erlc
- Add a --fullpath option to Dialyzer (include version 2.4.2)
- Many fixes in erts
- Remove hipe constants pool
- Partial support for recursive structs and unions
- It is now possible to use SSH to sign and verify binary data.
- typer has been rewritten
Changes R14B01 (http://www.erlang.org/download/otp_src_R14B01.readme)
- New ETS option compressed, to enable a more compact storage
format at the expence of heavier table operations
- There is now a new function inet:getifaddrs/0 modeled after
C library function getifaddrs() on BSD and Linux that reports
existing interfaces and their addresses on the host
- Multiple crashes and infinite loops fixed
- AES CTR encryption support in crypto
- erl_call: remove get_hostent
- The Erlang VM now supports Unicode filenames
- New ETS option compressed
Changes in R14B (http://www.erlang.org/download/otp_src_R14B.readme)
- Large parts of the ethread library have been rewritten.
- The changed API of the ethread library has also caused
modifications in the Erlang runtime system.
- Some Built In Functions (BIFs) are now autoimported
- Added erlang:system_info(build_type)
- A number of memory leaks in the crypto NIF library have been fixed
- erl_call: fix multiple buffer overflows
- NIF 64-bit integer support
- Removed some potential vulnerabilities from the Erlang Port
Mapper Daemon (epmd)
- Replaced the old http client api module (http) with the new,
httpc in the users guide.
- inet6 improvements
- ssh fixes
- many ssl improvements/fixes
- wx crash fix
Changes in R14A (http://www.erlang.org/download/otp_src_R14A.readme)
- R14A is a major new release of Erlang/OTP.
- The module binary from EEP31 (and EEP9) is implemented
- It is now possible for the user to provide specific callback
modules that handle test configuration data
- New NIF features
- Receive statements that can only read out a newly created
reference are now specially optimized so that it will execute
in constant time regardless of the number of messages in the
receive queue for the process.
- The run_test script has been replaced by a program (with the
same name) which can be executed without explicit installation
- eprof has been reimplemented with support in the Erlang
virtual machine and is now both faster (i.e. slows down the
code being measured less) and scales much better
Changes in R13B04 (http://www.erlang.org/download/otp_src_R13B04.readme)
- Many documentation and documentation build improvements
- cross-compile/build improvements
- buffer overflow fix
- telnet keep alive fixes
- compiler crash on boolean ifs
- -Werror for erlc fixed
- macro overloading implemented
- the crypto module now supports Blowfish
- explicit top directories in archive files are now optional
- add lock profiling tool: lcnt
- httpd methods "PUT" and "DELETE" now allowed + others fixes
to resolver routine
- compression supported when copying between mnesia nodes
SunOS, Java and ODBC support by Filip Hajny
and some tests by Matthias Kretschmer.
Changes in R13B03
-----------------
There are mostly error corrections, but also some new functionality.
Some highlights in the R13B03 release are:
- Native Implemented Functions (NIFs) still experimental but very useful.
- The documentation is built in a new way using xsltproc and Apache FOP.
The layout is changed both in HTML and PDF versions. This is the first
step, more changes and improvements will come in the following releases.
Changes between R13A and R13B02 are unknown.
Changes in R13A
---------------
1.1 Erlang Language and Run-time System
Multi-core and SMP performance improvements
There SMP performance is significantly improved:
- multiple, scheduler specific run queues;
- further optimized message passing;
- CPU-bound scheduler threads.
Unicode support as described in EEP10
New BIF's: atom_to_binary/2, binary_to_atom/2, binary_to_existing_atom/2.
Independent Erlang clusters on the same host
1.2 New Applications
Reltool, release management tool.
WxErlang
1.3 New features in Existing Applications
Common_test
- SSH and SFTP support
- test case groups
Dialyzer
- opaque type declarations;
- UTF segments handling
SSL
- pure Erlang implementation (except crypto routines)
STDLIB
- scanner has been augmented to return white-space, comments
and exact location of tokens.
=== SMP Support ===
The major news is the support for SMP (Symmetric MultiProcessing).
SMP is supported by most modern operating systems like Linux, Windows, Mac OSx,
Solaris and is becoming more important now when dual processors,
hyper-threading technology and multi-core systems are a reality.
With Erlang, most of the problems which occur in multi-threaded programs have
been solved once and for all in the Erlang VM and do not have to be handled by
the application programmers.
In the SMP version of the Erlang virtual machine, there can be many process
schedulers running in separate OS threads. As default there will be as many
schedulers as there are processors or processor cores on the system.
The SMP support is totally transparent for the Erlang programs. That is, there
is no need to change or recompile existing programs. Programs with built-in
assumptions about sequential execution must be rewritten in order to take
advantage of the SMP support, however.
In this release, the Erlang VM supports SMP with focus on stability. There will
follow a number of subsequent steps with necessary optimizations and support
for more platforms.
=== Erlang Language and Related Issues ===
* The andalso and orelse operators are now allowed to be used in guards.
That also applies to match specifications.
* The BIF is_record/3 can now be used in guards. Also, is_record/3 can now
be called without an erlang: module prefix for consistency with the other
is_* functions.
* The compiler options ignore_try and ignore_cond, which allowed code that
used unquoted try or cond as atoms or record tags, has been removed. Old
code that depended on the options need to be revised to have occurrences
of try or cond as atom or record tags single-quoted. (Note: Although cond
is a reserved keyword, there is no cond statement. It might be introduced
in a future release.)
* (ERTS 5.4.8) The new fun M:F/A construct creates a fun that refers to the
latest version of M:F/A. This syntax is meant to replace tuple funs {M,F}
which have many problems.
* (ERTS 5.4.8) The new type test is_function(Fun, Arity) -- which may be
used in guards -- test whether Fun is a fun that can be applied to Arity
arguments.
=== New Applications ===
Dialyzer
Dialyzer is a static analysis tool that identifies software discrepancies such
as type errors, unreachable code, unnecessary tests, etc in single Erlang
modules or entire (sets of) applications.
Inviso
The Inviso application, together with some new extensions to Runtime_Tools, is
aimed at providing features for efficient tracing of production Erlang/OTP
systems:
* Distributed tracing - tracing on any number of Erlang nodes.
* Autostart - tracing during system start-up.
* Overload protection - mechanisms for suspending and later reactivating
tracing, should an overload situation occur.
* Enhanced use of meta tracing.
* Trace cases - predefined specifications of what to trace.
* Off-line merging and formatting of log files.
Inviso is still under development. An easier-to-use trace tool, using the
features listed above, is planned to be released as an R11B patch in Q3/Q4
2006.
SSH
The SSH application is an Erlang implementation of the secure shell protocol.
It is considered to be a beta release, meaning there can be changes made to the
API before it reaches 1.0.
=== Existing Applications ===
Compiler
(Compiler 4.3.6) It is now possible to encrypt the debug information in Beam
files.
Debugger
(Debugger 2.0) The debugger can now handle the try/catch language construct.
Inets
The Erlang implementation of the TFTP procotcol, tftp, is now documented.
Kernel
In Kernel 2.10.X, several bug fixes and improvements have been made in global ,
the global name registration facility.
OS_Mon
(OS_Mon 2.0) The entire OS_Mon application (code and documentation) has been
reviewed and consequently updated with the goal to make the application more
robust, homogeneous and easier to configure.
STDLIB
Added the zip module with functions for reading and creating zip archives.
systems, but the code that take care of them is inly implemented
on Linux. This made the build go into an infinite loop on NetBSD.
Disable floating point exceptions on NetBSD/amd64 for now, until
I get around implementing and testing the necessary sigaction glue.
been updated in more than two years.)
- Add a buildlink3.mk file.
- Make the Java dependency optional, and disable this option by default (this
will make erlang build in more bulk builds).
Ok by wiz.
