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diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index acc19f250a..628df1b9bd 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -32,6 +32,481 @@ <p>This document describes the changes made to the ERTS application.</p> +<section><title>Erts 9.0</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fix various bugs regarding loading, upgrade and purge + of HiPE compiled code:</p> <list> <item>The native code + memory for a purged module was never deallocated.</item> + <item>Wrong functions could in some cases be called after + a module upgrade.</item> + <item><c>erlang:check_process_code</c> did not check for + recursive calls made from native code.</item> </list> + <p> + Own Id: OTP-13968</p> + </item> + <item> + <p> + Hipe optional LLVM backend does require LLVM version 3.9 + or later as older versions forced strong dependencies on + erts internals structures.</p> + <p> + Own Id: OTP-14238</p> + </item> + <item> + <p> + Slogans in crash dumps have been extended to print more + complex terms.</p> + <p> + Own Id: OTP-14303</p> + </item> + <item> + <p> + Fixed bug when using <c>enif_inspect_binary</c> in + combination with <c>enif_copy</c>. In some circumstances + the inspected binary could be realloced by the + <c>enif_copy</c> call when it shouldn't have been.</p> + <p> + Own Id: OTP-14304</p> + </item> + <item> + <p> + Use <c>-fno-PIE</c> for Gentoo Hardened and others that + don't accept linker flag <c>-no-pie</c>.</p> + <p> + Own Id: OTP-14307 Aux Id: PR-1379 </p> + </item> + <item> + <p> + Disable hipe for <c>ppc64le</c> architecture (little + endian) as it is not, and has never been, supported. It + was earlier equated with <c>ppc64</c> (big endian) which + lead to broken build without <c>--disable-hipe</c>.</p> + <p> + Own Id: OTP-14314 Aux Id: ERL-369, PR-1394 </p> + </item> + <item> + <p> + Fix 'epmd -kill' to return a failure exit status code if + epmd was not killed because of some error.</p> + <p> + Own Id: OTP-14324</p> + </item> + <item> + <p>Fixed the following dirty scheduler related bugs:</p> + <list> <item><p>the <c>+SDPcpu</c> command line argument + could cause the amount of dirty CPU schedulers to be set + to zero</p></item> + <item><p><c>erlang:system_flag(multi_scheduling, _)</c> + failed when only one normal scheduler was used together + with dirty scheduler support</p></item> </list> + <p> + Own Id: OTP-14335</p> + </item> + <item> + <p> + Fix erlexec to handle mismatch in sysconf and proc fs + when figuring out the cpu topology. This behaviour has + been seen when using docker together with + <c>--cpuset-cpus</c>.</p> + <p> + Own Id: OTP-14352</p> + </item> + <item> + <p> + Fixed memory segment cache used for multiblock carriers. + Huge (> 2GB) memory segments could cause a VM crash. + Creation of such huge memory segments used for multiblock + carriers is however very uncommon.</p> + <p> + Own Id: OTP-14360 Aux Id: ERL-401, PR-1417 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Added <c>erlang:garbage_collect/2</c> that takes an + option list as the last argument that can be used to + control whether a minor or a major garbage collection is + to be done. Doing a minor collection only collects terms + that have recently died, but is cheaper than a mjor + collection.</p> + <p> + Own Id: OTP-11695</p> + </item> + <item> + <p> + Optimized test for tuples with an atom as first element.</p> + <p> + Own Id: OTP-12148</p> + </item> + <item> + <p> + Erlang literals are no longer copied during process to + process messaging.</p> + <p> + Own Id: OTP-13529</p> + </item> + <item> + <p>Add support in the <c>erl_nif</c> API for asynchronous + message notifications when sockets or other file + descriptors are ready to accept read or write operations. + The following functions have been added:</p> <list> + <item><p>enif_select</p></item> + <item><p>enif_monitor_process</p></item> + <item><p>enif_demonitor_process</p></item> + <item><p>enif_compare_monitors</p></item> + <item><p>enif_open_resource_type_x</p></item> </list> + <p> + Own Id: OTP-13684</p> + </item> + <item> + <p>There are two new guard BIFs '<c>floor/1</c>' and + '<c>ceil/1</c>'. They both return integers. In the + '<c>math</c>' module, there are two new BIFs with the + same names that return floating point values.</p> + <p> + Own Id: OTP-13692</p> + </item> + <item> + <p> + Remove deprecated <c>erlang:hash/2</c>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13827</p> + </item> + <item> + <p>Replaced usage of deprecated symbolic <seealso + marker="erts:erlang#type-time_unit"><c>time + unit</c></seealso> representations.</p> + <p> + Own Id: OTP-13831 Aux Id: OTP-13735 </p> + </item> + <item> + <p> + Added support in zlib for extraction of the inflation + dictionary.</p> + <p> + Own Id: OTP-13842</p> + </item> + <item> + <p> + The previously used purge strategy has been removed. The + optional purge strategy introduced in ERTS version 8.1 is + now the only strategy available.</p> + <p> + The new purge strategy is slightly incompatible with the + old strategy. Previously processes holding <c>fun</c>s + that referred to the module being purged either failed a + soft purge, or was killed during a hard purge. The new + strategy completely ignores <c>fun</c>s. If <c>fun</c>s + referring to the code being purged exist, and are used + after a purge, an exception will be raised upon usage. + That is, the behavior will be exactly the same as the + case when a <c>fun</c> is received by a process after the + purge.</p> + <p> + For more information see the documentation of <seealso + marker="erts:erlang#check_process_code/3"><c>erlang:check_process_code/3</c></seealso>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13844 Aux Id: OTP-13833 </p> + </item> + <item> + <p> + Dirty schedulers are now enabled by default when the + runtime system is built with SMP support.</p> + <p> + Own Id: OTP-13860</p> + </item> + <item> + <p> + Improved ETS lookup/insert/delete speed for large + <c>set</c>, <c>bag</c> and <c>duplicate_bag</c> by a + significant reduction of the hash load factor. This speed + improvement comes at the expense of less than one word + per table entry. Tables with less than 256 entries are + not affected at all.</p> + <p> + Own Id: OTP-13903</p> + </item> + <item> + <p> + The NIF library <c>reload</c> feature is not supported + anymore. It has been marked as deprecated since OTP R15B. + This means that you are only allowed to do one successful + call to <c>erlang:load_nif/2</c> for each module + instance. A second call to <c>erlang:load_nif/2</c> will + return <c>{error, {reload, _}}</c> even if the NIF + library imlements the <c>reload</c> callback.</p> + <p> + Runtime upgrade of a NIF library is still supported by + using the Erlang module upgrade mechanics with a current + and an old module instance existing at the same time with + their corresponding NIF libraries.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13908</p> + </item> + <item> + <p> + Add <c>erlang:system_info(atom_count)</c> and + <c>erlang:system_info(atom_limit)</c> to provide a way to + retrieve the current and maximum number of atoms.</p> + <p> + Own Id: OTP-13976</p> + </item> + <item> + <p>The function <c>fmod/2</c> has been added to the + <c>math</c> module.</p> + <p> + Own Id: OTP-14000</p> + </item> + <item> + <p> + <c>erlang:load_nif/2</c> returns new error type + <c>notsup</c> when called for a HiPE compiled module, + which is not supported.</p> + <p> + Own Id: OTP-14002</p> + </item> + <item> + <p> + Add driver and nif lock instrumentation to lcnt</p> + <p> + Own Id: OTP-14069</p> + </item> + <item> + <p> + Reduce memory pressure by converting sub-binaries to + heap-binaries when possible. This is done during garbage + collection.</p> + <p> + Own Id: OTP-14149</p> + </item> + <item> + <p> + Dirty schedulers are now enabled and supported on Erlang + runtime systems with SMP support.</p> + <p> + Besides support for dirty NIFs also support for dirty + BIFs and dirty garbage collection have been introduced. + All garbage collections that potentially will take a long + time to complete are now performed on dirty schedulers if + enabled.</p> + <p> + <seealso + marker="erts:erlang#statistics_scheduler_wall_time"><c>erlang:statistics(scheduler_wall_time)</c></seealso> + now also includes information about dirty CPU schedulers. + Code using <c>erlang:statistics(scheduler_wall_time)</c> + may have to be rewritten to take this incompatibility + into consideration.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14152</p> + </item> + <item> + <p>Atoms may now contain arbitrary Unicode + characters.</p> + <p> + Own Id: OTP-14178</p> + </item> + <item> + <p> + Introduce an event manager in Erlang to handle OS + signals. A subset of OS signals may be subscribed to and + those are described in the Kernel application.</p> + <p> + Own Id: OTP-14186</p> + </item> + <item> + <p> + The <c>escript</c> program now handles symbolic links to + escripts.</p> + <p> + This is useful for standalone systems with + <c>escript</c>s residing on a bin directory not included + in the execution path (as it may cause their <c>erl</c> + program(s) to override the desired one). Instead the + <c>escript</c>s can be referred to via symbolic links + from a bin directory in the path.</p> + <p> + Own Id: OTP-14201 Aux Id: PR-1293 </p> + </item> + <item> + <p> + All uses of the magic binary kludge has been replaced by + uses of erlang references.</p> + <p> + A magic binary was presented as an empty binary, but + actually referred other data internally in the Erlang VM. + Since they were presented as empty binaries, different + magic binaries compared as equal, and also lost their + internal data when passed out of an erlang node.</p> + <p> + The new usage of references has not got any of these + strange semantic issues, and the usage of these + references has been optimized to give the same + performance benefits as well as memory usage benefits as + magic binaries had.</p> + <p> + A couple of examples of previous uses of magic binaries + are match specifications and NIF resources.</p> + <p> + Own Id: OTP-14205</p> + </item> + <item> + <p> + The non-smp emulators have been deprecated and are + scheduled for removal in OTP-21.</p> + <p> + In preperations for this, the threaded non-smp emulator + is no longer built by default and has to be enabled using + the --enable-plain-emulator to configure.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14272</p> + </item> + <item> + <p> + Allow HiPE to run on VM built with + <c>--enable-m32-build</c>.</p> + <p> + Own Id: OTP-14330 Aux Id: PR-1397 </p> + </item> + <item> + <p> + Upgraded the OTP internal PCRE library from version 8.33 + to version 8.40. This library is used for implementation + of the <seealso marker="stdlib:re"><c>re</c></seealso> + regular expressions module.</p> + <p> + Besides various bug fixes, the new version allows for + better stack protection. In order to utilize this + feature, the stack size of normal scheduler threads is + now by default set to 128 kilo words on all platforms. + The stack size of normal scheduler threads can be set + upon system start by passing the <seealso + marker="erts:erl#sched_thread_stack_size"><c>+sss</c></seealso> + command line argument to the <seealso + marker="erts:erl"><c>erl</c></seealso> command.</p> + <p> + See <url + href="http://pcre.org/original/changelog.txt"><c>http://pcre.org/original/changelog.txt</c></url> + for information about changes made to PCRE between the + versions 8.33 and 8.40.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14331 Aux Id: ERL-208 </p> + </item> + <item> + <p> + Remove generation of atoms in old latin1 external format. + The old latin1 format can still be decoded but is never + generated by <c>term_to_binary</c> or sent on a + distribution channel. The new utf8 format for atoms was + introduced in OTP R16. An OTP 20 node can therefore not + connect to nodes older than R16.</p> + <p> + Own Id: OTP-14337</p> + </item> + <item> + <p> + Added function <c>re:version/0</c> which returns + information about the OTP internal PCRE version used for + implementation of the <c>re</c> module.</p> + <p> + Own Id: OTP-14347 Aux Id: PR-1412 </p> + </item> + <item> + <p> + Added new debug bif <c>erlang:list_to_port/1</c>.</p> + <p> + Own Id: OTP-14348</p> + </item> + <item> + <p> + Various improvements of timer management internally in + the VM. These improvements both reduced memory + consumption of timer wheels as well as reduce the amount + of work that has to be performed in order to handle + timers.</p> + <p> + Own Id: OTP-14356</p> + </item> + <item> + <p> Sockets can now be bound to device (SO_BINDTODEVICE) + on platforms where it is supported. </p> <p> This has + been implemented e.g to support VRF-Lite under Linux; see + <url + href="https://www.kernel.org/doc/Documentation/networking/vrf.txt"> + VRF </url>, and GitHub pull request <url + href="https://github.com/erlang/otp/pull/1326">#1326</url>. + </p> + <p> + Own Id: OTP-14357 Aux Id: PR-1326 </p> + </item> + <item> + <p>Added the following <seealso + marker="erl"><c>erl</c></seealso> command line arguments + with which you can set suggested stack for dirty + schedulers:</p> <taglist> <tag><seealso + marker="erl#dcpu_sched_thread_stack_size"><c>+sssdcpu</c></seealso></tag> + <item><p>for dirty CPU schedulers</p></item> + <tag><seealso + marker="erl#dio_sched_thread_stack_size"><c>+sssdio</c></seealso></tag> + <item><p>for dirty IO schedulers</p></item> </taglist> + <p>The default suggested stack size for dirty schedulers + is 40 kilo words.</p> + <p> + Own Id: OTP-14380</p> + </item> + <item> + <p> + Changed erts startup program name, argv 0, to use the + environment variable <c>ESCRIPT_NAME</c> so that + <c>erlc</c>, <c>dialyzer</c>, <c>typer</c>, + <c>ct_run</c>, or the escript name can be seen with + external programs, such as ps and htop (depending on + options), on unix.</p> + <p> + If environment variable <c>ESCRIPT_NAME</c> is not set, + argv 0 of the invoking program will be used, e.g. the + name will be <c>erl</c>, <c>cerl</c>, or the soft link + name.</p> + <p> + Own Id: OTP-14381</p> + </item> + <item> + <p> + Improvements of <c>escript</c> documentation.</p> + <p> + Own Id: OTP-14384 Aux Id: OTP-14201 </p> + </item> + <item> + <p> + Add function <c>enif_hash</c> for NIFs to calculate hash + values of arbitrary terms.</p> + <p> + Own Id: OTP-14385 Aux Id: PR-1413 </p> + </item> + </list> + </section> + +</section> + <section><title>Erts 8.3.3</title> <section><title>Fixed Bugs and Malfunctions</title> |