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diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index b4ebef72f4..eba4cdf06f 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -30,6 +30,715 @@ </header> <p>This document describes the changes made to the ERTS application.</p> +<section><title>Erts 6.0</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + The option dupnames did not work as intended in re. When + looking for names with {capture, [Name, ...]}, re:run + returned a random instance of the match for that name, + instead of the leftmost matching instance, which was what + the documentation stated. This is now corrected to adhere + to the documentation. The option {capture,all_names} + along with a re:inspect/2 function is also added to + further help in using named subpatterns.</p> + <p> + Own Id: OTP-11205</p> + </item> + <item> + <p> + Allow loading of NIF library with unicode path name</p> + <p> + Own Id: OTP-11408</p> + </item> + <item> + <p> + Allow loading of driver with unicode path name</p> + <p> + Own Id: OTP-11549</p> + </item> + <item> + <p> + Fixed a bug where starting Erlang without having an open + stdin on fd 0 would sometimes deadlock the emulator when + terminating.</p> + <p> + Own Id: OTP-11558</p> + </item> + <item> + <p> + The option '-names' in epmd now works on Windows (Thanks + to Johannes Weißl)</p> + <p> + Own Id: OTP-11565</p> + </item> + <item> + <p> + Correction of the examples in escript documentation. + (Thanks to Pierre Fenoll).</p> + <p> + Own Id: OTP-11577</p> + </item> + <item> + <p> + Fix bs_get_integer instruction</p> + <p> + The instruction bs_get_integer could unnecessarily + trigger a garbage collection in failure cases which is + unwanted or outright dangerous.</p> + <p> + Ex:</p> + <p> + <<X:Sz,_/bits>> = <<"some + binary">></p> + <p> + Previously, if Sz induced X to a bignum it would reserved + memory size this on the heap via a garbage collection + before checking if the size could actually match.</p> + <p> + It will now check the binary size before triggering a + collection.</p> + <p> + Own Id: OTP-11581</p> + </item> + <item> + <p> + Remove heap space overestimation in <c>binary_to_term</c> + (and remote message reception) for integers in the + intervals [-2147483648,-1] and [256,2147483647] on 64-bit + emulators.</p> + <p> + Own Id: OTP-11585</p> + </item> + <item> + <p> + Add support for detecting the separate tinfo library from + ncurses (Thanks to Dirkjan Ochtman)</p> + <p> + Own Id: OTP-11590</p> + </item> + <item> + <p> + Deprecation warning for system_flag(cpu_topology) has + been extended for removal in OTP 18 (Thanks to Steve + Vinoski for the update)</p> + <p> + Own Id: OTP-11602</p> + </item> + <item> + <p> + Documentation improvement regarding some awkward wording + around the +spp flag. (Thanks to Brian L. Troutwine )</p> + <p> + Own Id: OTP-11607</p> + </item> + <item> + <p> + Fixed bug where sendfile would return the wrong error + code for a remotely closed socket if the socket was in + passive mode. (Thanks to Vincent Siliakus for reporting + the bug.)</p> + <p> + Own Id: OTP-11614</p> + </item> + <item> + <p> + Increase garbage collection tenure rate</p> + <p>The garbage collector tries to maintain the previous + heap block size during a minor gc, i.e. 'need' is not + utilized in determining the size of the new heap, instead + it relies on tenure and garbage to be sufficiently + large.</p> + <p>In instances during intense growing with exclusively + live data on the heap coupled with delayed tenure, + fullsweeps would be triggered directly after a minor gc + to make room for 'need' since the new heap would be + full.</p> + <p>To remedy this, the tenure of terms on the minor heap + will always happen (if it is below the high watermark) + instead of every other minor gc.</p> + <p>Characteristics Impact: Reduced CPU-time spent in + garbage collection but may infer delays in collecting + garbage from the heap. Tweak 'fullsweep_after' options to + increase gc pressure if needed.</p> + <p> + Own Id: OTP-11617</p> + </item> + <item> + <p> + Fix bug when comparing integers with floats larger than + 2^992. The bug could potentially cause memory corruption + on 32-bit emulators.</p> + <p> + Own Id: OTP-11618</p> + </item> + <item> + <p> + Cross-compilation fixes for TileraMDE-3.0.1.125620</p> + <p> + Own Id: OTP-11635</p> + </item> + <item> + <p> + sendfile no longer uses async threads by default</p> + <p> + This has been done because a slow client attack is + possible if the async thread pool is used. The scenario + is:</p> + <p> + Client does a request for a file and then slowly receives + the file one byte at a time. This will eventually fill + the async thread pool with blocking sendfile operations + and thus starving the vm of all file operations.</p> + <p> + If you still want to use the async threads pool for + sendfile an option to enable it has been introduced.</p> + <p> + Thanks to Christopher Faulet for identifying this + vulnerability.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11639</p> + </item> + <item> + <p> + Do proper rollback of calls to + <c>enif_open_resource_type</c> when load/upgrade + callbacks of NIF library return failure.</p> + <p> + Own Id: OTP-11722</p> + </item> + <item> + <p> + Changed the default configuration when configuring with + <c>$ERL_TOP/configure</c> to be the same as when + configuring with <c>$ERL_TOP/otp_build configure</c>.</p> + <p> + Previously floating point exceptions got enabled by + default on Linux when HiPE was enabled when configuring + with <c>$ERL_TOP/configure</c>, but not when configuring + with <c>$ERL_TOP/otp_build configure</c>. The default is + now in both cases not to use floating point exceptions + since there still exist unresolved issues with floating + point exceptions on Linux.</p> + <p> + For more information see <seealso + marker="doc/installation_guide:INSTALL"><c>$ERL_TOP/HOWTO/INSTALL.md</c></seealso>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11723</p> + </item> + <item> + <p> + A comment in erl_db_tree.c no longer differ from the + code. (Thanks to Cobus Carstens)</p> + <p> + Own Id: OTP-11793</p> + </item> + <item> + <p> + Fix epmd debug functionality for VxWorks (Thanks to Jay + True)</p> + <p> + Own Id: OTP-11808</p> + </item> + <item> + <p> + Use closefrom/2 when available in child_setup (Thanks to + Rick Reed and Anthony Ramine)</p> + <p> + Own Id: OTP-11809</p> + </item> + <item> + <p> + Fix dtrace/systemtap bug where the probe arguments would + be concatenated due to faulty length calculation. </p> + <p> + Thanks to Michal Ptaszek and Scott Lystig Fritchie</p> + <p> + Own Id: OTP-11816</p> + </item> + <item> + <p> + It is now better documented that the <c>+fn*</c> flags to + <c>erl</c> also affect how command line parameters and + environment variables are read. (Thanks to Vlad + Dumitrescu)</p> + <p> + Own Id: OTP-11818</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Options to set match_limit and match_limit_recursion are + added to re:run. The option report_errors is also added + to get more information when re:run fails due to limits + or compilation errors.</p> + <p> + Own Id: OTP-10285</p> + </item> + <item> + <p> Dialyzer's <c>unmatched_return</c> warnings have been + corrected. </p> + <p> + Own Id: OTP-10908</p> + </item> + <item> + <p> + A common case is to wrap an argument to + <c>list_to_binary/1</c> in a list to ensure conversion + can happen even though the argument may already be a + binary. Take special care of this case and do not copy + binary.</p> + <p> + Impact: May cause incompatibility since a single binary + is no longer copied. Use <c>binary:copy/1,2</c> instead.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11082</p> + </item> + <item> + <p> + Make erlang:open_port/2 spawn and spawn_executable handle + unicode.</p> + <p> + Own Id: OTP-11105</p> + </item> + <item> + <p> + Handle unicode (widestring) in erl, erlc, heart, etc on + windows.</p> + <p> + Own Id: OTP-11135</p> + </item> + <item> + <p> + The version of the PCRE library Used by Erlang's re + module is raised to 8.33 from 7.6. This means, among + other things, better Unicode and Unicode Character + Properties support. New options connected to PCRE 8.33 + are also added to the re module (ucd, notempty_atstart, + no_start_optimize). PCRE has extended the regular + expression syntax between 7.6 and 8.33, why this imposes + a potential incompatibility. Only very complicated + regular expressions may be affected, but if you know you + are using obscure features, please test run your regular + expressions and verify that their behavior has not + changed.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11204</p> + </item> + <item> + <p>Filenames containing UTF-8 encoded characters can now + be handled by erlc.</p> + <p>If you have set the <c>ERLC_EMULATOR</c> environment + variable, note that <c>erlc</c> in OTP 17 will only work + with <c>erl</c> in OTP 17 since the protocol between the + <c>erlc</c> program and the <c>erl_compile</c> module has + changed.</p> + <p> + Own Id: OTP-11248</p> + </item> + <item> + <p> + By giving --enable-static-{nifs,drivers} to configure it + is now possible to statically linking of nifs and drivers + to the main Erlang VM binary. At the moment only the asn1 + and crypto nifs of the Erlang/OTP nifs and drivers have + been prepared to be statically linked. For more details + see the Installation Guide in the System documentation.</p> + <p> + Own Id: OTP-11258</p> + </item> + <item> + <p> + Erlang/OTP has been ported to the realtime operating + system OSE. The port supports both smp and non-smp + emulator. For details around the port and how to started + see the User's Guide in the <seealso + marker="ose:ose_intro">ose</seealso> application. </p> + <p> + Note that not all parts of Erlang/OTP has been ported. </p> + <p> + Notable things that work are: non-smp and smp emulators, + OSE signal interaction, crypto, asn1, run_erl/to_erl, + tcp, epmd, distribution and most if not all non-os + specific functionality of Erlang.</p> + <p> + Notable things that does not work are: udp/sctp, os_mon, + erl_interface, binding of schedulers.</p> + <p> + Own Id: OTP-11334</p> + </item> + <item> + <p> + Add the {active,N} socket option for TCP, UDP, and SCTP, + where N is an integer in the range -32768..32767, to + allow a caller to specify the number of data messages to + be delivered to the controlling process. Once the + socket's delivered message count either reaches 0 or is + explicitly set to 0 with inet:setopts/2 or by including + {active,0} as an option when the socket is created, the + socket transitions to passive ({active, false}) mode and + the socket's controlling process receives a message to + inform it of the transition. TCP sockets receive + {tcp_passive,Socket}, UDP sockets receive + {udp_passive,Socket} and SCTP sockets receive + {sctp_passive,Socket}. </p> + <p> + The socket's delivered message counter defaults to 0, but + it can be set using {active,N} via any gen_tcp, gen_udp, + or gen_sctp function that takes socket options as + arguments, or via inet:setopts/2. New N values are added + to the socket's current counter value, and negative + numbers can be used to reduce the counter value. + Specifying a number that would cause the socket's counter + value to go above 32767 causes an einval error. If a + negative number is specified such that the counter value + would become negative, the socket's counter value is set + to 0 and the socket transitions to passive mode. If the + counter value is already 0 and inet:setopts(Socket, + [{active,0}]) is specified, the counter value remains at + 0 but the appropriate passive mode transition message is + generated for the socket.</p> + <p> + Thanks to Steve Vinoski</p> + <p> + Own Id: OTP-11368</p> + </item> + <item> + <p> + A new optional scheduler utilization balancing mechanism + has been introduced. For more information see the + <seealso marker="erl#+sub"><c>+sub</c></seealso> command + line argument.</p> + <p> + Characteristics impact: None, when not enabled. When + enabled, changed timing in the system, normally a small + overhead due to measuring of utilization and calculating + balancing information. On some systems, such as old + Windows systems, the overhead can be quite substantial. + This time measurement overhead highly depend on the + underlying primitives provided by the OS.</p> + <p> + Own Id: OTP-11385</p> + </item> + <item> + <p> + A call to either the <c>garbage_collect/1</c> BIF or the + <c>check_process_code/2</c> BIF may trigger garbage + collection of another processes than the process calling + the BIF. The previous implementations performed these + kinds of garbage collections without considering the + internal state of the process being garbage collected. In + order to be able to more easily and more efficiently + implement yielding native code, these types of garbage + collections have been rewritten. A garbage collection + like this is now triggered by an asynchronous request + signal, the actual garbage collection is performed by the + process being garbage collected itself, and finalized by + a reply signal to the process issuing the request. Using + this approach processes can disable garbage collection + and yield without having to set up the heap in a state + that can be garbage collected.</p> + <p> + The <seealso + marker="erts:erlang#garbage_collect/2"><c>garbage_collect/2</c></seealso>, + and <seealso + marker="erts:erlang#check_process_code/3"><c>check_process_code/3</c></seealso> + BIFs have been introduced. Both taking an option list as + last argument. Using these, one can issue asynchronous + requests.</p> + <p> + <c>code:purge/1</c> and <c>code:soft_purge/1</c> have + been rewritten to utilize asynchronous + <c>check_process_code</c> requests in order to + parallelize work.</p> + <p> + Characteristics impact: A call to the + <c>garbage_collect/1</c> BIF or the + <c>check_process_code/2</c> BIF will normally take longer + time to complete while the system as a whole wont be as + much negatively effected by the operation as before. A + call to <c>code:purge/1</c> and <c>code:soft_purge/1</c> + may complete faster or slower depending on the state of + the system while the system as a whole wont be as much + negatively effected by the operation as before.</p> + <p> + Own Id: OTP-11388 Aux Id: OTP-11535, OTP-11648 </p> + </item> + <item> + <p> + Cleanup 'Buckets' and 'Time left' fields in crashdump to + ease parsing.</p> + <p> + Own Id: OTP-11419</p> + </item> + <item> + <p> + Add sync option to file:open/2.</p> + <p> + The sync option adds the POSIX O_SYNC flag to the open + system call on platforms that support the flag or its + equivalent, e.g., FILE_FLAG_WRITE_THROUGH on Windows. For + platforms that don't support it, file:open/2 returns + {error, enotsup} if the sync option is passed in. Thank + to Steve Vinoski and Joseph Blomstedt</p> + <p> + Own Id: OTP-11498</p> + </item> + <item> + <p> + erlang:binary_to_term will now cost an appropriate amount + of reductions and will interrupt (yield) for reschedule + if the term is big. This avoids too long schedules when + binary_to_term is used. (Thanks to Svante Karlsson for + the original patch)</p> + <p> + Impact: Programs running binary_to_term on large binaries + will run more smoothly, but rescheduling will impact the + single process performance of the BIF. Single threaded + benchmarks might show degraded performance of the BIF, + while general system behaviour will be improved.</p> + <p> + Own Id: OTP-11535 Aux Id: OTP-11388 </p> + </item> + <item> + <p> + Added high resolution icon for windows. (Thanks to Daniel + Goertz for the inspiration.)</p> + <p> + Own Id: OTP-11560</p> + </item> + <item> + <p> + Migration of memory carriers has been enabled by default + on all ERTS internal memory allocators based on the + <seealso + marker="erts_alloc#alloc_util"><c>alloc_util</c></seealso> + framework except for <c>temp_alloc</c>. That is, <seealso + marker="erts_alloc#M_acul"><c>+M<S>acul + de</c></seealso> is default for these allocators. Note + that this also implies changed allocation strategies for + all of these allocators. They will all now use the + "address order first fit carrier best fit" strategy.</p> + <p> + By passing <c>+Muacul 0</c> on the command line, all + configuration changes made by this change will be + reverted.</p> + <p> + Characteristics impact: Improved memory characteristics + with a smaller memory footprint at the expense of a quite + small performance cost.</p> + <p> + Own Id: OTP-11604 Aux Id: OTP-10279 </p> + </item> + <item> + <p>A clarification has been added to the documentation of + <c>-on_load()</c> in the Reference Manual that it is only + recommended for loading NIF libraries.</p> + <p> + Own Id: OTP-11611</p> + </item> + <item> + <p><c>+fnaw</c> is now default when starting the + emulator; it used to be <c>+fnl</c>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11612</p> + </item> + <item> + <p> + EEP43: New data type - Maps</p> + <p> + With Maps you may for instance: <taglist> <item><c>M0 = + #{ a => 1, b => 2}, % create + associations</c></item> <item><c>M1 = M0#{ a := 10 }, % + update values</c></item> <item><c>M2 = M1#{ "hi" => + "hello"}, % add new associations</c></item> <item><c>#{ + "hi" := V1, a := V2, b := V3} = M2. % match keys with + values</c></item> </taglist></p> + <p> + For information on how to use Maps please see the + <seealso marker="doc/reference_manual:maps">Reference + Manual</seealso>.</p> + <p> + The current implementation is without the following + features: <taglist> <item>No variable keys</item> + <item>No single value access</item> <item>No map + comprehensions</item> </taglist></p> + <p> + Note that Maps is <em>experimental</em> during OTP 17.0.</p> + <p> + Own Id: OTP-11616</p> + </item> + <item> + <p> + The previously deprecated driver API function + <c>driver_async_cancel()</c> has been removed. Due to + this, the driver API version has been bumped to 3.0.</p> + <p> + Thanks to Steve Vinoski.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11628</p> + </item> + <item> + <p> + Experimental "dirty scheduler" functionality has been + introduced. In order to try the functionality out, you + need to pass the command line argument + <c>--enable-dirty-schedulers</c> to <c>configure</c> when + building the system.</p> + <p> + Dirty schedulers can currently only be used by NIFs on a + system with SMP support. More information can be found in + the <seealso + marker="erl_nif#dirty_nifs"><c>erl_nif(3)</c></seealso> + documentation, the <seealso + marker="erl"><c>erl(1)</c></seealso> documentation, and + in the git commit comment of commit + 'c1c03ae4ee50e58b7669ea88ec4d29c6b2b67c7b'.</p> + <p> + Note that the functionality is <em>experimental</em>, and + <em>not supported</em>. This functionality <em>will</em> + be subject to backward incompatible changes. You should + <em>not</em> enable the dirty scheduler functionality on + production systems. It is only provided for testing.</p> + <p> + Thanks to Steve Vinoski.</p> + <p> + Own Id: OTP-11629</p> + </item> + <item> + <p> + Improve reduction cost and yielding of + <c>term_to_binary</c>. The reduction cost is increased + and garbage collection is disabled during yield.</p> + <p> + Impact: Improves system responsiveness when + <c>term_to_binary</c> is called with large terms without + significant degradation of single threaded performance.</p> + <p> + Own Id: OTP-11648 Aux Id: OTP-11388 </p> + </item> + <item> + <p> + By default, the system's version of zlib will be used, + provided its version is 1.2.4 or higher; otherwise the + built-in zlib will be used. The built-in version of zlib + has been bumped to 1.2.8. (Use the + <c>--enable-builtin-zlib</c> option to <c>configure</c> + to force the use of the built-in zlib.)</p> + <p> + Own Id: OTP-11669</p> + </item> + <item> + <p> + The default float encoding in binary_to_term and + external_size has been changed to use minor_mode 1 + instead of 0.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11738</p> + </item> + <item> + <p> + Introduced the <c>configure</c> option + <c>--with-assumed-cache-line-size=SIZE</c>. For more + information see <seealso + marker="doc/installation_guide:INSTALL"><c>$ERL_TOP/HOWTO/INSTALL.md</c></seealso>.</p> + <p> + Own Id: OTP-11742</p> + </item> + <item> + <p> + Halfword emulator is marked as deprecated. It still works + as before but is planned to be removed in a future major + release.</p> + <p> + Own Id: OTP-11777</p> + </item> + <item> + <p> + The external format for Maps has changed in a way that is + not compatible with the format used in OTP 17.0-rc1 and + OTP 17.0-rc2.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11782</p> + </item> + <item> + <p> + Fixed faulty make dependency that would make some make + versions fail while building gen_git_version.mk.</p> + <p> + Own Id: OTP-11784</p> + </item> + <item> + <p> + Introduced functionality for allowing old drivers and NIF + libraries to be loaded during a transition period. For + more information see <seealso + marker="erts:erl_driver#version_management">the version + management section in the <c>erl_driver(3)</c> + documentation</seealso> and <seealso + marker="erts:erl_nif#version_management">the version + management section in the <c>erl_nif(3)</c> + documentation</seealso>.</p> + <p> + Own Id: OTP-11799</p> + </item> + <item> + <p> + Support file paths longer than 259 characters on Windows. + Long absolute paths are automatically converted to UNC + format with a <c>\\?\</c> prefix which is the only way to + represent long paths. The 259 character limit still + applies for individual file names, relative paths and the + current working directory.</p> + <p> + Own Id: OTP-11813</p> + </item> + <item> + <p> + Document that escript:create/2 also accepts a 3-elements + tuple containing files and zip:create/3 options to build + a zip file.</p> + <p> + Thanks to Pierre Fenoll</p> + <p> + Own Id: OTP-11827</p> + </item> + <item> + <p> + Add systemd socket activation for epmd.</p> + <p> + Thanks to Matwey V. Kornilov</p> + <p> + Own Id: OTP-11829</p> + </item> + </list> + </section> + +</section> + <section><title>Erts 5.10.4</title> <section><title>Fixed Bugs and Malfunctions</title> |