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diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index da470b51ec..5736d366eb 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -31,6 +31,460 @@ </header> <p>This document describes the changes made to the ERTS application.</p> +<section><title>Erts 10.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Do not allocate new bitstring/binary when an empty binary + is appended.</p> + <p> + Own Id: OTP-15535 Aux Id: PR-2055 </p> + </item> + <item> + <p> + Document that <c>process_info(_, current_function)</c> + can return <c>{current_function, undefined}</c> in case + of execution of native code.</p> + <p> + Own Id: OTP-15543 Aux Id: PR-2089 </p> + </item> + <item> + <p> + Fixed bug in <c>ets:select</c>, <c>ets:match</c> and + friends which could cause the table to remain fixated (as + if <c>ets:safe_fixtable</c> had been called) after the + call returned. This could happen for <c>protected</c> + tables if another concurrent running process transfered + table ownership to the process during its + ets:select/match call. Ownership can be transfered using + either <c>ets:give_away</c> or the <c>heir</c> table + option.</p> + <p> + Own Id: OTP-15672</p> + </item> + <item> + <p>Fixed a Windows-specific bug in <c>file:list_dir/1</c> + that caused it to misbehave on network shares.</p> + <p> + Own Id: OTP-15693</p> + </item> + <item> + <p> + Fixed bug when calling <c>enif_whereis_*</c> from NIF + resource destructor. Symtoms could be emulator crash or + hanging scheduler threads.</p> + <p> + Own Id: OTP-15694 Aux Id: ERL-863 </p> + </item> + <item> + <p>Fixed a bug in the error case of <c>apply/3</c>, where + the exception would erroneously have an empty argument + list in some cases.</p> + <p> + Own Id: OTP-15698</p> + </item> + <item> + <p>A bug has been fixed in the <c>maps</c> implementation + that could cause a crash or memory usage to grow until + the machine ran out of memory. This could happen when + inserting a new key-value pair with a key <c>K1</c> + containing a binary <c>B1</c> into a map <c>M</c> having + a key <c>K2</c> with a binary <c>B2</c> if the following + conditions were met:</p> <list> <item><c>B1 =/= + B2</c></item> <item><c>size(B1) >= 4294967296</c></item> + <item><c>size(B2) >= 4294967296</c></item> + <item><c>size(M) >= 32</c></item> <item><c>(size(B1) rem + 4294967296) == (size(B2) rem 4294967296)</c></item> + <item>the first <c>(size(B1) rem 4294967296)</c> bytes + are the same both in <c>B1</c> and <c>B2</c></item> + <item>substituting <c>B1</c> in <c>K1</c> with <c>B2</c> + would create a term with the same value as + <c>K2</c></item> </list> <p>The root cause of the problem + is that the <c>maps</c> implementation only hashed the + first <c>(X rem 4294967296)</c> bytes of binaries so that + different binaries could get the same hash value + independently of the hash seed.</p> + <p> + Own Id: OTP-15707</p> + </item> + <item> + <p> + <c>term_to_binary()</c> and distributed sends will now + throw a <c>system_limit</c> exception instead of + producing erroneous results when trying to encode a + binary larger than 4 GB.</p> + <p> + Own Id: OTP-15708</p> + </item> + <item> + <p> + The vxworks configure has been updated to respect the + environment CFLAGS.</p> + <p> + Own Id: OTP-15773</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Add support for Erlang Distribution protocol to split the + payload of large signals into several fragments. This + allows other processes to communicate uninterrupted + during the transmission of these signals.</p> + <p> + Own Id: OTP-13397</p> + </item> + <item> + <p> + A simple socket API is provided through the socket + module. This is a low level API that does *not* replace + gen_[tcp|udp|sctp]. It is intended to *eventually* + replace the inet driver, but not the high level + gen-modules (gen_tcp, gen_udp and gen_sctp). It also + provides a basic API that facilitates the implementation + of other protocols, than TCP, UDP and SCTP. </p> + <p> + Known issues are; No support for the Windows OS + (currently).</p> + <p> + Own Id: OTP-14831</p> + </item> + <item> + <p>Added NIF functions <seealso + marker="erl_nif#enif_set_pid_undefined"><c>enif_set_pid_undefined</c></seealso>, + <seealso + marker="erl_nif#enif_is_pid_undefined"><c>enif_is_pid_undefined</c></seealso> + and <seealso + marker="erl_nif#enif_compare_pids"><c>enif_compare_pids</c></seealso>.</p> + <p> + Own Id: OTP-15011 Aux Id: PR-2147 </p> + </item> + <item> + <p>Underutilized memory segments (carriers) can now move + between all allocator instances, rather than just between + instances of the same type, which greatly reduces memory + usage in some scenarios. </p> + <p> + Own Id: OTP-15063</p> + </item> + <item> + <p>The emulator will now mark free blocks in pooled + carriers with <c>madvise(2) + MADV_FREE</c> (or similar), + letting the OS reclaim the associated physical memory if + necessary.</p> + <p> + Own Id: OTP-15075</p> + </item> + <item> + <p> + New <c>ERL_NIF_SELECT_CANCEL</c> feature added to + <c>enif_select</c> in order to cancel (or "deselect") a + read or write event on a previously selected file + descriptor.</p> + <p> + Own Id: OTP-15095</p> + </item> + <item> + <p> + ETS option <c>write_concurrency</c> now also affects and + improves the scalability of <c>ordered_set</c> tables. + The implementation is based on a data structure called + contention adapting search tree, where the lock + granularity adapts to the actual amount of concurrency + exploited by the applications in runtime.</p> + <p> + Own Id: OTP-15128</p> + </item> + <item> + <p> + Build configuration of the <c>crypto</c> application has + been moved from the <c>erts</c> application into the + <c>crypto</c> application.</p> + <p> + Own Id: OTP-15129</p> + </item> + <item> + <p>Anonymous functions that don't capture environment are + now created at load-time instead of in run-time.</p> + <p> + Own Id: OTP-15195 Aux Id: PR-1812 </p> + </item> + <item> + <p> + Optimize updates of maps with identical keys and values. + E.g. in the example below the original Map will be reused + as the return of the update.</p> + <p> + 1> Map = #{ a => b }. #{ a => b } 2> Map#{ a := b }.</p> + <p> + Own Id: OTP-15211 Aux Id: PR-1889 </p> + </item> + <item> + <p> + Optimize <c>binary:match/2</c> and + <c>binary:matches/2</c> to use memchr internally.</p> + <p> + Own Id: OTP-15238 Aux Id: PR-1803 </p> + </item> + <item> + <p> + The runtime system used to terminate when a message + larger than 2 Gb was passed over the distribution. The + send operation will now instead throw a + <c>system_limit</c> exeption.</p> + <p> + Own Id: OTP-15261</p> + </item> + <item> + <p> + Change the first module called by erts to be names + erl_init instead of otp_ring0. systools in sasl have been + updated to reflect this change.</p> + <p> + Own Id: OTP-15336 Aux Id: PR-1825 </p> + </item> + <item> + <p> + Minor adjustments made to build system for parallel + configure.</p> + <p> + Own Id: OTP-15340 Aux Id: OTP-14625 </p> + </item> + <item> + <p> + Two new NIF interface functions <c>enif_select_read</c> + and <c>enif_select_write</c>. They are similar to + existing <c>enif_select</c> but allow a custom event + message as argument.</p> + <p> + Own Id: OTP-15349 Aux Id: PR-2084 </p> + </item> + <item> + <p>The embedded copy of <c>zlib</c> has been updated from + <c>1.2.8</c> to <c>1.2.11</c>.</p> + <p>Note that this copy is only used as a fallback when + the target platform doesn't provide any <c>zlib</c> + development libraries. If your system provides + <c>zlib</c> then it will be used even if it is older than + <c>1.2.11</c>.</p> + <p> + Own Id: OTP-15351 Aux Id: ERL-749 </p> + </item> + <item> + <p> + New NIF function <c>enif_make_monitor_term</c>.</p> + <p> + Own Id: OTP-15362 Aux Id: PR-2127 </p> + </item> + <item> + <p>Appending lists (The ++ operator) will now yield + properly on large inputs.</p> + <p> + Own Id: OTP-15427</p> + </item> + <item> + <p>The <c>length/1</c> BIF used to calculate the length + of the list in one go without yielding, even if the list + was very long. In OTP 22, <c>length/1</c> will yield when + called with a long lists.</p> + <p> + Own Id: OTP-15439</p> + </item> + <item> + <p> + Processes sending messages are now punished with a + reduction cost based on message size. That is, a process + sending a large message will yield earlier than before.</p> + <p> + Own Id: OTP-15513 Aux Id: ERL-773 </p> + </item> + <item> + <p>The transitory emulator option <c>+ztma true</c> + (introduced in OTP 21.3) has been removed.</p> + <p> + Own Id: OTP-15581 Aux Id: OTP-15580 </p> + </item> + <item> + <p>In OTP 22, HiPE (the native code compiler) is not + fully functional. The reasons for this are:</p> + <p>There are new BEAM instructions for binary matching + that the HiPE native code compiler does not support.</p> + <p>The new optimizations in the Erlang compiler create + new combination of instructions that HiPE currently does + not handle correctly.</p> + <p>If erlc is invoked with the <c>+native</c> option, and + if any of the new binary matching instructions are used, + the compiler will issue a warning and produce a BEAM file + without native code.</p> + <p> + Own Id: OTP-15596</p> + </item> + <item> + <p> + The termination behaviour of processes has changed to + allow processes to yield while sending link exit/monitor + down signals.</p> + <p> + The erl crash dump as been expanded to now also include + processes that are termenating but have not yet + terminated.</p> + <p> + Own Id: OTP-15610</p> + </item> + <item> + <p> + The dist messages EXIT, EXIT2 and MONITOR_DOWN have been + updated with new versions that send the reason term as + part of the payload of the message instead of as part of + the control message.</p> + <p> + The old versions are still present and can be used when + communicating with nodes that don't support the new + versions.</p> + <p> + Own Id: OTP-15611</p> + </item> + <item> + <p> + When sending messages, exit, exit2 and monitor down + distributed signals, the process sending will now yield + appropriately.</p> + <p> + This means that a terminating process will yield and + possibly be suspended on busy distribution entries while + they are terminating. This means that any memory held by + such processes will not be released until after all + exit/monitor down signals have been sent.</p> + <p> + Own Id: OTP-15612</p> + </item> + <item> + <p> + All external pids/ports/refs created by + erlang:list_to_pid/port/ref debug functions now compare + equal to any other pid/port/ref with the same number from + that node.</p> + <p> + Before this change they compared differently because the + node creation of the pid/port/ref did not compare equal + to any real pid/port/ref creation.</p> + <p> + This will mostly effect pids/ports/refs typed in the + shell.</p> + <p> + Own Id: OTP-15613</p> + </item> + <item> + <p> + The <c>persistent_term</c> functions <c>put/2</c> and + <c>erase/1</c> are now yeliding.</p> + <p> + Own Id: OTP-15615</p> + </item> + <item> + <p> + A new <seealso + marker="erlang#dist_ctrl_set_opt/3"><c>erlang:dist_ctrl_set_opt(DHandle, + get_size, Value)</c></seealso> option has been added. + This option makes it possible to configure the + distribution channel identified by <c>DHandle</c> so that + <seealso + marker="erlang#dist_ctrl_get_data/1"><c>erlang:dist_ctrl_get_data(DHandle)</c></seealso> + also returns the size of the data to pass over the + channel.</p> + <p> + Own Id: OTP-15617</p> + </item> + <item> + <p>Previously, all ETS tables used centralized counter + variables to keep track of the number of items stored and + the amount of memory consumed. These counters can cause + scalability problems (especially on big NUMA systems). + This change adds an implementation of a decentralized + counter and modifies the implementation of ETS so that + ETS tables of type <c>ordered_set</c> with + <c>write_concurrency</c> enabled use the decentralized + counter. Experiments indicate that this change + substantially improves the scalability of ETS + <c>ordered_set</c> tables with <c>write_concurrency</c> + enabled in scenarios with frequent <c>ets:insert/2</c> + and <c>ets:delete/2</c> calls.</p> + <p> + Own Id: OTP-15623 Aux Id: PR-2190 </p> + </item> + <item> + <p>The <c>iolist_size/1</c> function is now yielding + which means that an Erlang/OTP system will be responsive + even if the applications running on the system frequently + call <c>iolist_size/1</c> with large iolists.</p> + <p> + Own Id: OTP-15631</p> + </item> + <item> + <p> + A simple test suite for the net module has been added.</p> + <p> + Own Id: OTP-15635</p> + </item> + <item> + <p>Added the NIF function <c>enif_term_type</c>, which + helps avoid long sequences of <c>enif_is_xyz</c> by + returning the type of the given term. This is especially + helpful for NIFs that serialize terms, such as JSON + encoders, where it can improve both performance and + readability.</p> + <p> + Own Id: OTP-15640</p> + </item> + <item> + <p>The last call optimization is now applied to BIFs. + When calling a BIF in the tail position of a function, + the return address and stack frame will now be discarded + before calling the BIF. As consequence of this change, + the immediate caller of a tail-called BIF will no longer + be available in stack backtraces.</p> + <p> + Own Id: OTP-15674 Aux Id: PR-2177 </p> + </item> + <item> + <p> + Fix GC bug where distributed messages in a processes + mailbox would cause extra GCs. This can be very expensive + if there many messages in the mailbox.</p> + <p> + Own Id: OTP-15703</p> + </item> + <item> + <p>Internal documentation has now been added to the + <em>Erts</em> and <em>Compiler</em> applications.</p> + <p>The internal documents for <em>Erts</em> describe + miscellaneous interesting implementation details. Those + details can change at any time.</p> + <p>The internal documentation for <em>Compiler</em> + documents the API for the Core Erlang modules. While we + will not change those APIs without good reason, we don't + give the same guarantees about backward compatibility as + for the rest of the APIs in OTP.</p> + <p> + Own Id: OTP-15715</p> + </item> + <item> + <p>The performance of non-bignum integer arithmetic has + been improved.</p> + <p> + Own Id: OTP-15740</p> + </item> + </list> + </section> + +</section> + <section><title>Erts 10.3.4</title> <section><title>Fixed Bugs and Malfunctions</title> |