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diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index 36cf42c77f..d9ff8d9688 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -4,7 +4,7 @@ <chapter> <header> <copyright> - <year>2004</year><year>2015</year> + <year>2004</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -31,6 +31,4750 @@ </header> <p>This document describes the changes made to the ERTS application.</p> +<section><title>Erts 10.1.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A bug where the socket option 'pktoptions' caused a read + of uninitialized memory has been fixed. Would cause + malfunction on FreeBSD.</p> + <p> + Own Id: OTP-14297 Aux Id: OTP-15141 </p> + </item> + <item> + <p>Fixed a memory leak on errors when reading files.</p> + <p> + Own Id: OTP-15318</p> + </item> + <item> + <p>File access through UNC paths works again on Windows. + This regression was introduced in OTP 21.</p> + <p> + Own Id: OTP-15333 Aux Id: ERL-737 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix the seq_trace token to not be cleared when a process + receives messages sent by erts. Some examples of when + this could happen is all port BIFs, i.e. + <c>open_port</c>, <c>port_command</c> etc etc.</p> + <p> + Fix so that messages sent by nifs can be traced using + normal and <c>seq_trace</c> tracing.</p> + <p> + Own Id: OTP-15038 Aux Id: ERL-602 </p> + </item> + <item> + <p> + Fixed specs and documentation for <c>process_info</c> + item <c>monitored_by</c> to include port identifiers and + nif resources as possible types.</p> + <p> + Own Id: OTP-15180 Aux Id: ERL-648 </p> + </item> + <item> + <p> + Fix bug in generation of erl_crash.dump, which could + cause VM to crash.</p> + <p> + Bug exist since erts-9.2 (OTP-20.2).</p> + <p> + Own Id: OTP-15181</p> + </item> + <item> + <p> + Fix bug where ctrl-break or ctrl-c would not trigger the + break mode properly on Windows. This bug was introduced + in erts-10.0 (OTP-21).</p> + <p> + Own Id: OTP-15205</p> + </item> + <item> + <p> + Fix a performance bug for reception of UDP packages, + where a memory buffer would be reallocated when it should + not have been.</p> + <p> + Introduce a limit on the maximum automatic increase of + the UDP user-space buffer to the theoretical max of the + network PATH, i.e. 65535.</p> + <p> + Own Id: OTP-15206</p> + </item> + <item> + <p> + Fix alignment of erts allocator state internally in erts. + With the improper alignment the emulator would refuse to + start when compiled with clang on 32-bit systems.</p> + <p> + Own Id: OTP-15208 Aux Id: PR-1897 ERL-677 </p> + </item> + <item> + <p> + Fix bug where too many concurrent calls to + <c>erlang:open_port({spawn,"cmd"},...)</c> would result + in the emulator terminating with the reason "Failed to + write to erl_child_setup: ". After this fix the + <c>open_port</c> call will throw an <c>emfile</c> + exception instead.</p> + <p> + Own Id: OTP-15210</p> + </item> + <item> + <p> + Upgraded the ERTS internal PCRE library from version 8.41 + to version 8.42. See <url + href="http://pcre.org/original/changelog.txt">http://pcre.org/original/changelog.txt</url> + for information about changes made to PCRE. This library + implements major parts of the <seealso + marker="stdlib:re"><c>re</c></seealso> regular + expressions module.</p> + <p> + Own Id: OTP-15217</p> + </item> + <item> + <p> + Fix <c>open_port({fd,X,Y}, ...)</c> to release the file + descriptors from the pollset when closing the port. + Without this fix the same file descriptor number could + not be reused when doing multiple open_port and + port_close sequences.</p> + <p> + Own Id: OTP-15236 Aux Id: ERL-692 </p> + </item> + <item> + <p> + Fixed bug in <c>float_to_list/2</c> and + <c>float_to_binary/2</c> with options + <c>[{decimals,0},compact]</c> causing totally wrong + results. Bug exists since OTP-21.0.</p> + <p> + Own Id: OTP-15276 Aux Id: PR-1920 </p> + </item> + <item> + <p> + Fixed bug in <c>erlang:memory</c> causing <c>ets</c> to + report too much. This small false memory leak (16 bytes + each time) can only happen when a specific race condition + occurs between scheduler threads on a table with option + <c>write_concurrency</c>.</p> + <p> + Own Id: OTP-15278</p> + </item> + <item> + <p> + Minor <c>configure</c> test fixes</p> + <p> + Own Id: OTP-15282</p> + </item> + <item> + <p> + Improved robustness of distribution connection setup. In + OTP-21.0 a truly asynchronous connection setup was + introduced. This is further improvement on that work to + make the emulator more robust and also be able to recover + in cases when involved Erlang processes misbehave.</p> + <p> + Own Id: OTP-15297 Aux Id: OTP-15279, OTP-15280 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + The socket options <c>recvtos</c>, <c>recvttl</c>, + <c>recvtclass</c> and <c>pktoptions</c> have been + implemented in the socket modules. See the documentation + for the <c>gen_tcp</c>, <c>gen_udp</c> and <c>inet</c> + modules. Note that support for these in the runtime + system is platform dependent. Especially for + <c>pktoptions</c> which is very Linux specific and + obsoleted by the RFCs that defined it.</p> + <p> + Own Id: OTP-15145 Aux Id: ERIERL-187 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.8</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + As of ERTS version 10.0 (OTP 21.0) the + <c>erl_child_setup</c> program, which creates port + programs, ignores <c>TERM</c> signals. This setting was + unintentionally inherited by port programs. Handling of + <c>TERM</c> signals in port programs has now been + restored to the default behavior. That is, terminate the + process.</p> + <p> + Own Id: OTP-15289 Aux Id: ERIERL-235, OTP-14943, ERL-576 </p> + </item> + <item> + <p> + The fix made for OTP-15279 in erts-10.07 (OTP-21.0.8) was + not complete. It could cause a new connection attempt to + be incorrectly aborted in certain cases. This fix will + amend that flaw.</p> + <p> + Own Id: OTP-15296 Aux Id: OTP-15279, ERIERL-226 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.7</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A process could get stuck in an infinite rescheduling + loop between normal and dirty schedulers. This bug was + introduced in ERTS version 10.0.</p> + <p> + Thanks to Maxim Fedorov for finding and fixing this + issue.</p> + <p> + Own Id: OTP-15275 Aux Id: PR-1943 </p> + </item> + <item> + <p> + Garbage collection of a distribution entry could cause an + emulator crash if <c>net_kernel</c> had not brought + previous connection attempts on it down properly.</p> + <p> + Own Id: OTP-15279 Aux Id: ERIERL-226 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.6</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A race between termination of a process and resume of the + same process via <c>erlang:resume_process/1</c> could + cause the VM to crash. This bug was introduced in erts + version 10.0 (OTP 21.0).</p> + <p> + Own Id: OTP-15237</p> + </item> + <item> + <p> + When tracing on <c>running</c>, <c>in</c> trace events + could be lost when a process was rescheduled between a + dirty and a normal scheduler.</p> + <p> + Own Id: OTP-15269 Aux Id: ERL-713 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a bug which caused an emulator crash when + <c>enif_send()</c> was called by a NIF that executed on a + dirty scheduler. The bug was either triggered when the + NIF called <c>enif_send()</c> without a message + environment, or when the process executing the NIF was + <c>send</c> traced.</p> + <p> + Own Id: OTP-15223</p> + </item> + <item> + <p> + Fixed a bug causing some Erlang references to be + inconsistently ordered. This could for example cause + failure to look up certain elements with references as + keys in search data structures. This bug was introduced + in R13B02.</p> + <p> + Thanks to Simon Cornish for finding the bug and supplying + a fix.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-15225</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a bug that prevented the <c>noshell</c> option + from working correctly on Mac OS X and BSD.</p> + <p> + Own Id: OTP-15169</p> + </item> + <item> + <p>Fixed a crash when matching directly against a literal + map using a single key that had been saved on the + stack.</p> + <p> + Own Id: OTP-15184</p> + </item> + <item> + <p>Fix node crash when passing a bad time option to + <c>file:read_file_info/2</c>.</p> + <p> + Own Id: OTP-15196</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a scheduler bug that caused normal schedulers to + run dirty code.</p> + <p> + Own Id: OTP-15154</p> + </item> + <item> + <p> + Fixed a bug in <c>erlang:trace_info/2</c> which caused + the emulator to crash when a bad argument was passed. The + bug was introduced in ERTS version 10.0.</p> + <p> + Own Id: OTP-15183 Aux Id: ERL-670 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a rare bug that could cause processes to be + scheduled after they had been freed.</p> + <p> + Own Id: OTP-15067 Aux Id: ERL-573 </p> + </item> + <item> + <p>Fixed a race condition in the inet driver that could + cause receive to hang when the emulator was compiled with + gcc 8.</p> + <p> + Own Id: OTP-15158 Aux Id: ERL-654 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The keys used in <c>os:getenv</c> and <c>os:putenv</c> + are case-insensitive again on Windows.</p> + <p> + Own Id: OTP-15147 Aux Id: ERL-644 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 10.0</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + The type specifications for <c>file:posix/0</c> and + <c>inet:posix/0</c> have been updated according to which + errors file and socket operations should be able to + return.</p> + <p> + Own Id: OTP-14019 Aux Id: ERL-550 </p> + </item> + <item> + <p> + Fix error printout from run_erl and a bug that could + cause unintended fds to be leaked into the started + program.</p> + <p> + Own Id: OTP-14537 Aux Id: PR1529 </p> + </item> + <item> + <p> File operations used to accept <seealso + marker="kernel:file#type-name_all">filenames</seealso> + containing null characters (integer value zero). This + caused the name to be truncated and in some cases + arguments to primitive operations to be mixed up. + Filenames containing null characters inside the filename + are now <em>rejected</em> and will cause primitive file + operations to fail. </p> <p> Also environment variable + operations used to accept <seealso + marker="kernel:os#type-env_var_name">names</seealso> and + <seealso + marker="kernel:os#type-env_var_value">values</seealso> of + environment variables containing null characters (integer + value zero). This caused operations to silently produce + erroneous results. Environment variable names and values + containing null characters inside the name or value are + now <em>rejected</em> and will cause environment variable + operations to fail. </p> <p>Primitive environment + variable operations also used to accept the <c>$=</c> + character in environment variable names causing various + problems. <c>$=</c> characters in environment variable + names are now also <em>rejected</em>. </p> <p>Also + <seealso + marker="kernel:os#cmd/1"><c>os:cmd/1</c></seealso> now + reject null characters inside its <seealso + marker="kernel:os#type-os_command">command</seealso>. + </p> <p><seealso + marker="erts:erlang#open_port/2"><c>erlang:open_port/2</c></seealso> + will also reject null characters inside the port name + from now on.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14543 Aux Id: ERL-370 </p> + </item> + <item> + <p> + Fix bugs related to the bookkeeping of microstate + accounting states.</p> + <p> + Own Id: OTP-14652</p> + </item> + <item> + <p><c>os:putenv</c> and <c>os:getenv</c> no longer access + the process environment directly and instead work on a + thread-safe emulation. The only observable difference is + that it's <em>not</em> kept in sync with libc + <c>getenv(3)</c> / <c>putenv(3)</c>, so those who relied + on that behavior in drivers or NIFs will need to add + manual synchronization.</p> <p>On Windows this means that + you can no longer resolve DLL dependencies by modifying + the <c>PATH</c> just before loading the driver/NIF. To + make this less of a problem, the emulator now adds the + target DLL's folder to the DLL search path.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14666</p> + </item> + <item> + <p>Corrected <c>erlang:is_builtin(erlang, M, F)</c> to + return <c>true</c> for <c>apply/2</c> and + <c>yield/0</c>.</p> + <p> + Own Id: OTP-14713 Aux Id: ERL-500 </p> + </item> + <item> + <p>Fixed a bug where the PATH environment variable wasn't + updated correctly on a release downgrade, effectively + keeping the PATH of the new release.</p> + <p> + Own Id: OTP-14719</p> + </item> + <item> + <p>A receive optimization that avoids scanning the entire + message queue when receiving a message containing a + freshly created reference could in rare circumstances + (involving recursive calls to the functions that does the + receive) cause the receive to hang. This has been + corrected.</p> + <p> + Own Id: OTP-14782 Aux Id: ERL-511 </p> + </item> + <item> + <p> + Fix building of Erlang/OTP on platforms which have small + data area with short addressing. For example the + PowerPC/RTEMS platform.</p> + <p> + Own Id: OTP-14909 Aux Id: PR-1692 </p> + </item> + <item> + <p>Fixed a crash when <c>enif_make_binary</c> is called + with a binary produced by <c>enif_inspect_binary</c> in a + different environment.</p> + <p> + Own Id: OTP-14931</p> + </item> + <item> + <p>Fixed a crash when <c>enif_make_binary</c> is called + more than once with a binary that had previously been + added to an <c>enif_ioq</c>.</p> + <p> + Own Id: OTP-14932</p> + </item> + <item> + <p> + The erl_child_setup program now ignores SIGTERM signals.</p> + <p> + Own Id: OTP-14943 Aux Id: ERL-576 </p> + </item> + <item> + <p> + Force 64-bit alignment on pre-allocators on architectures + which needs it.</p> + <p> + Own Id: OTP-14977</p> + </item> + <item> + <p> + Fixed a bug where dirty scheduler picked up non-dirty + work.</p> + <p> + Own Id: OTP-14978</p> + </item> + <item> + <p> + Calls to <c>gen_tcp:send/2</c> on closed sockets now + returns <c>{error, closed}</c> instead of + <c>{error,enotconn}</c>.</p> + <p> + Own Id: OTP-15001</p> + </item> + <item> + <p> + <c>erlang:monotonic_time/1</c> failed with <c>badarg</c> + when passing the <c>perf_counter</c> time unit as + argument.</p> + <p> + Own Id: OTP-15008</p> + </item> + <item> + <p> + Fix bug where rapid <c>init:restart()</c> calls would + sometimes crash because a code load request leaked in + between the restarts.</p> + <p> + Own Id: OTP-15013</p> + </item> + <item> + <p> + Improve <c>float_to_list(F, [{decimals,D}])</c> to closer + conform with <c>io_lib:format("~.*f", [D,F])</c>.</p> + <p> + There are however, still cases when <c>float_to_list</c> + does not produce the exact same result as + <c>io_lib:format</c>, especially for large values + <c>F</c> and/or many decimals <c>D</c>.</p> + <p> + Own Id: OTP-15015 Aux Id: OTP-14890 </p> + </item> + <item> + <p>Fixed a deadlock that would occur on certain + allocators when a reallocation failed with <c>+ramv</c> + enabled.</p> + <p> + Own Id: OTP-15024</p> + </item> + <item> + <p> + Fix bug that made it impossible to use an erl_tracer as + the seq_trace trace receiver.</p> + <p> + Own Id: OTP-15029</p> + </item> + <item> + <p> + Fix bug where a large (> 1 GB) emulator generated error + logger message would cause the emulator to crash.</p> + <p> + Own Id: OTP-15032</p> + </item> + <item> + <p>The emulator will no longer crash when reading the + file information of an ordinary file that has an NTFS + reparse point, such as files stored in a OneDrive-mapped + folder.</p> + <p> + Own Id: OTP-15062 Aux Id: ERL-615 </p> + </item> + <item> + <p> + Fixed bug in <c>enif_binary_to_term</c> which could cause + memory corruption for immediate terms (atoms, small + integers, pids, ports, empty lists).</p> + <p> + Own Id: OTP-15080</p> + </item> + <item> + <p> + Fixed bug in <c>erlang:system_profile/2</c> that could + cause superfluous <c>{profile,_,active,_,_}</c> messages + for terminating processes.</p> + <p> + Own Id: OTP-15085</p> + </item> + <item> + <p> + On OSs with per thread CPU time support, change + <c>cpu_timestamp</c> in <seealso + marker="erlang#trace/3">erlang:trace/3</seealso> to use + it instead of per process CPU time. This makes this + option useable on such OSs when running multiple + schedulers.</p> + <p> + Own Id: OTP-15090</p> + </item> + <item> + <p> + Fix segfault in abort_signal_task which could happen if a + port terminated while there were outstanding port tasks + that were not signals, for example a + ready_input/ready_output event.</p> + <p> + Own Id: OTP-15108 Aux Id: ERL-621 </p> + </item> + <item> + <p> + Fixed bug in <c>ets</c> that could cause VM crash if + process A terminates after fixating a table and process B + deletes the table at "the same time". The table fixation + could be done with <c>ets:safe_fixtable</c> or if process + A terminates in the middle of a long running + <c>select</c> or <c>match</c> call.</p> + <p> + Own Id: OTP-15109</p> + </item> + <item> + <p>Owner and group changes through + <c>file:write_file_info</c>, <c>file:change_owner</c>, + and <c>file:change_group</c> will no longer report + success on permission errors.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-15118</p> + </item> + <item> + <p> + Fix a bug error reporting from escripts on windows where + the error message would get garbled.</p> + <p> + Own Id: OTP-15119 Aux Id: PR-1826 </p> + </item> + <item> + <p> + Fix segfault when a process is interally re-scheduled + while being traced for in out events. This bug was + introduced in erts-8.0 (OTP-19.0).</p> + <p> + Own Id: OTP-15125</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p>It is now possible to open device files and FIFOs with + <c>file:open/2</c>.</p> + <p> + Own Id: OTP-11462</p> + </item> + <item> + <p> + The <c>erlang:system_flag(scheduler_wall_time,Bool)</c> + call is now reference counted and will be turned off if + the (last) process that started the performance + statistics dies. Thus it is no longer possible to start + the statistics with <c>rpc:call(Node, erlang, + system_flag, [scheduler_wall_time, true])</c> since it + will be turned off directly afterwards when the rpc + process dies.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-11694</p> + </item> + <item> + <p>A new logging API is added to Erlang/OTP, see the + <seealso + marker="kernel:logger"><c>logger(3)</c></seealso> manual + page, and section <seealso + marker="kernel:logger_chapter">Logging</seealso> in the + Kernel User's Guide.</p> + <p>Calls to <c>error_logger</c> are automatically + redirected to the new API, and legacy error logger event + handlers can still be used. It is, however, recommended + to use the Logger API directly when writing new code.</p> + <p>Notice the following potential incompatibilities:</p> + <list> <item><p>Kernel configuration parameters + <c>error_logger</c> still works, but is overruled if the + default handler's output destination is configured with + Kernel configuration parameter <c>logger</c>.</p> <p>In + general, parameters for configuring error logger are + overwritten by new parameters for configuring + Logger.</p></item> <item><p>The concept of SASL error + logging is deprecated, meaning that by default the SASL + application does not affect which log events are + logged.</p> <p>By default, supervisor reports and crash + reports are logged by the default Logger handler started + by Kernel, and end up at the same destination (terminal + or file) as other standard log event from Erlang/OTP.</p> + <p>Progress reports are not logged by default, but can be + enabled by setting the primary log level to info, for + example with the Kernel configuration parameter + <c>logger_level</c>.</p> <p>To obtain backwards + compatibility with the SASL error logging functionality + from earlier releases, set Kernel configuration parameter + <c>logger_sasl_compatible</c> to <c>true</c>. This + prevents the default Logger handler from logging any + supervisor-, crash-, or progress reports. Instead, SASL + adds a separate Logger handler during application start, + which takes care of these log events. The SASL + configuration parameters <c>sasl_error_logger</c> and + <c>sasl_errlog_type</c> specify the destination (terminal + or file) and severity level to log for these + events.</p></item></list> + <p> + Since Logger is new in Erlang/OTP 21.0, we do reserve the + right to introduce changes to the Logger API and + functionality in patches following this release. These + changes might or might not be backwards compatible with + the initial version.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13295</p> + </item> + <item> + <p> + <c>gen_sctp:connect_init/4</c> or rather connect in + <c>inet_drv.c</c> for SCTP has been fixed to not check + the write file descriptor for writeability after a + connect, since for SCTP (SOCK_SEQPACKET) that property + does not seem to be any kind of indicator for when a + connect has finished. This fixes connects that the OS + returned as "in progress" that was misinterpreted by + <c>gen_sctp:connect_init</c> as failed.</p> + <p> + Own Id: OTP-13760 Aux Id: PR-1592 </p> + </item> + <item> + <p>The file driver has been rewritten as a NIF, + decreasing the latency of file operations. Notable + incompatibilities are:</p> <list> <item><p>The + <c>use_threads</c> option for <c>file:sendfile/5</c> no + longer has any effect; we either use non-blocking + <c>sendfile(2)</c> or fall back to <c>file:read</c> + + <c>gen_tcp:send</c>. </p></item> <item><p>The + file-specific DTrace probes have been removed. The same + effect can be achieved with normal tracing together with + the <c>nif__entry</c>/<c>nif__return</c> probes to track + scheduling.</p></item> </list> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14256</p> + </item> + <item> + <p>The I/O polling functionality of erts has been + re-written to better make use of the OSs polling + mechanisms. This change means that erts will now always + prefer to use a kernel-polling mechanism if possible. + Also all of the I/O polling has been moved to dedicated + threads instead of being placed in the scheduler + loops.</p> <p>As a result of this, the <c>erl</c> options + <c>+K</c> and <c>+secio</c> have been removed. It is + still possible to disable kernel-poll, but it has to be + done at compile time through the configure option + <c>--disable-kernel-poll</c>.</p> <p>The new <c>erl</c> + options <seealso marker="erl#+IOt"><c>+IOt</c></seealso> + and <seealso marker="erl#+IOp"><c>+IOp</c></seealso> can + be used to change how many IO poll threads and poll sets + that erts should use. See their respective documentation + for more details.</p> + <p> + Own Id: OTP-14346</p> + </item> + <item> + <p>Truly asynchronous auto-connect. Earlier, when + <c>erlang:send</c> was aimed toward an unconnected node, + the function would not return until the connection setup + had completed (or failed). Now the function returns + directly after the message has been enqueued and the + connection setup started.</p> + <p>The same applies to all distributed operations that + may trigger auto-connect, i.e. <c>'!'</c>, <c>send</c>, + <c>link</c>, <c>monitor</c>, <c>monitor_node</c>, + <c>exit/2</c> and <c>group_leader</c>.</p> + <p>The interface for all these functions are unchanged as + they do not return connection failures. The only + exception is <c>erlang:monitor</c> where a <em>possible + incompatibility</em> is introduced: An attempt to monitor + a process on a primitive node (such as erl_interface or + jinterface), where remote process monitoring is not + implemented, will no longer fail with <c>badarg</c> + exception. Instead a monitor will be created, but it will + only supervise the connection to the node.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14370</p> + </item> + <item> + <p>Changed the default behaviour of <c>.erlang</c> + loading: <c>.erlang</c> is no longer loaded from the + current directory. <c>c:erlangrc(PathList)</c> can be + used to search and load an <c>.erlang</c> file from user + specified directories.</p> <p><c>escript</c>, + <c>erlc</c>, <c>dialyzer</c> and <c>typer</c> no longer + load an <c>.erlang</c> at all.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14439</p> + </item> + <item> + <p> + New functionality for implementation of alternative + carriers for the Erlang distribution has been introduced. + This mainly consists of support for usage of distribution + controller processes (previously only ports could be used + as distribution controllers). For more information see + <seealso marker="erts:alt_dist#distribution_module">ERTS + User's Guide ➜ How to implement an Alternative Carrier + for the Erlang Distribution ➜ Distribution + Module</seealso>.</p> + <p> + Own Id: OTP-14459</p> + </item> + <item> + <p> + Add support for the lcc compiler and in extension the + Elbrus 2000 platform.</p> + <p> + Own Id: OTP-14492</p> + </item> + <item> + <p>Support for "tuple calls" have been removed from the + run-time system. Tuple calls was an undocumented and + unsupported feature which allowed the module argument for + an apply operation to be a tuple: <c>Var = dict:new(), + Var:size()</c>. This "feature" frequently caused + confusion, especially when such call failed. The + stacktrace would point out functions that don't exist in + the source code.</p> + <p>For legacy code that need to use parameterized modules + or tuple calls for some other reason, there is a new + compiler option called <c>tuple_calls</c>. When this + option is given, the compiler will generate extra code + that emulates the old behavior for calls where the module + is a variable.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14497</p> + </item> + <item> + <p>Creation of small maps with literal keys has been + optimized to be faster and potentially use less memory. + The keys are combined into a literal key tuple which is + put into the literal pool. The key tuple can be shared + between many instances of maps having the same keys.</p> + <p> + Own Id: OTP-14502</p> + </item> + <item> + <p> + When an exception is thrown, include the arguments of the + call in the stacktrace for BIFs <c>band</c>, <c>bor</c>, + <c>bsl</c>, <c>bsr</c>, <c>bxor</c>, <c>div</c>, + <c>rem</c> and the operators <c>+</c>, <c>-</c>, <c>*</c> + and <c>/</c>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14508</p> + </item> + <item> + <p> + The non-smp emulators have been removed. This means that + the configure options <c>--disable-threads</c> and + <c>--enable-plain-emulator</c> have been removed and + configure will now refuse to build Erlang/OTP on + platforms without thread support.</p> + <p> + In order to achieve a similar setup as the non-smp + emulator, it is possible to start Erlang/OTP with the + <c>+S 1</c> option.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14518</p> + </item> + <item> + <p>Modules that use floating point constants compiled + with R15 or earlier will need to be re-compiled before + they can be loaded.</p> + <p> + Own Id: OTP-14575</p> + </item> + <item> + <p> + Implementation of true asynchronous signaling between + processes in order to improve scalability. Signals + affected include exit, monitor, demonitor, monitor + triggered, link, unlink, and group leader.</p> + <p> + Own Id: OTP-14589</p> + </item> + <item> + <p> + Added a PGO (profile guided optimization) pass to the + build step of erts. This can be disabled by passing + --disable-pgo to configure.</p> + <p> + Own Id: OTP-14604</p> + </item> + <item> + <p> + Improved the performance of <c>binary:split</c> and + <c>binary:match</c>.</p> + <p> + Own Id: OTP-14610 Aux Id: PR-1480 </p> + </item> + <item> + <p> + It is not longer possible to disable dirty schedulers + when building erlang.</p> + <p> + Own Id: OTP-14613</p> + </item> + <item> + <p>Loaded BEAM code in a 64-bit system requires less + memory because of better packing of operands for + instructions.</p> + <p>These memory savings were achieved by major + improvements to the <c>beam_makeops</c> scripts used when + building the run time system and BEAM compiler. There is + also new for documentation for <c>beam_makeops</c> that + describes how new BEAM instructions and loader + transformations can be implemented. The documentation is + found in here in a source directory or git repository: + erts/emulator/internal_doc/beam_makeops.md. An online + version can be found here: + https://github.com/erlang/otp/blob/master/erts/emulator/internal_doc/beam_makeops.md</p> + <p> + Own Id: OTP-14626</p> + </item> + <item> + <p><c>file:read_file</c> has been changed to read the + content of files that report a size of 0 even when data + can be read from them. An example of such a file is + <c>/proc/cpuinfo</c> on Linux.</p> + <p> + Own Id: OTP-14637 Aux Id: ERL-327 PR-1524 </p> + </item> + <item> + <p> + It is no longer possible to disable the <c>temp_alloc</c> + allocator. Disabling it caused serious performance + degradations and was never what was wanted.</p> + <p> + Own Id: OTP-14651</p> + </item> + <item> + <p>The reduction cost of sending messages is now + constant. It will no longer scale according to the length + of the receiving process' message queue.</p> + <p> + Own Id: OTP-14667</p> + </item> + <item> + <p> + Improved loading of modules with <c>-on_load</c> + directive, to no longer block all schedulers when the + load operation is completed.</p> + <p> + Own Id: OTP-14680</p> + </item> + <item> + <p> + On platforms with real-time signals available, SIGRTMIN+1 + is now used as the internal scheduler suspend signal + instead of SIGUSR2.</p> + <p> + Own Id: OTP-14682</p> + </item> + <item> + <p>When the value returned from a '<c>catch</c>' + expression is ignored, no stacktrace will be built if an + exception is caught. That will save time and produce less + garbage. There are also some minor optimizations of + '<c>try</c>/<c>catch</c>' both in the compiler and + run-time system.</p> + <p> + Own Id: OTP-14683</p> + </item> + <item> + <p>The guarantees and non-guarantees of + <c>erlang:get_stacktrace/0</c> are now documented.</p> + <p> + Own Id: OTP-14687</p> + </item> + <item> + <p>There is a new syntax in '<c>try/catch</c>' for + retrieving the stacktrace without calling + '<c>erlang:get_stacktrace/0</c>'. See the reference + manual for a description of the new syntax. The + '<c>erlang:get_stacktrace/0</c>' BIF is now + deprecated.</p> + <p> + Own Id: OTP-14692</p> + </item> + <item> + <p> + New 'used' option for <c>binary_to_term/2</c> that will + also return number of bytes actually read from the + binary. This enables easy access to any extra data in the + binary located directly after the returned term.</p> + <p> + Own Id: OTP-14780</p> + </item> + <item> + <p> + Added more statistics for + <c>erlang:system_info({allocator,A})</c> in the + <c>mbcs_pool</c> section.</p> + <p> + Own Id: OTP-14795 Aux Id: ERL-88 </p> + </item> + <item> + <p>Added <c>enif_ioq_peek_head</c> to retrieve Erlang + terms from NIF IO queues without having to resort to + copying.</p> + <p> + Own Id: OTP-14797</p> + </item> + <item> + <p>There is a new option '<c>makedep_side_effect</c>' for + the compiler and <c>-MMD</c> for '<c>erlc</c>' that + generates dependencies and continues to compile as + normal.</p> + <p> + Own Id: OTP-14830</p> + </item> + <item> + <p>Added <c>ets:whereis/1</c> for retrieving the table + identifier of a named table.</p> + <p> + Own Id: OTP-14884</p> + </item> + <item> + <p><c>seq_trace</c> labels may now be any erlang + term.</p> + <p> + Own Id: OTP-14899</p> + </item> + <item> + <p> + Optimized the common case of <c>monitor</c> followed by + <c>send</c> to the same local process. The monitor signal + is now delayed in order to be piggybacked with the sent + message and thereby only get one lock operation on the + message queue of the receiver. A delayed monitor signal + is flushed if no <c>send</c> has been done at the latest + when the process is scheduled out.</p> + <p> + Own Id: OTP-14901</p> + </item> + <item> + <p> + Make hipe compiled code work on x86_64 (amd64) with OS + security feature PIE, where executable code can be loaded + into a random location. Old behavior, if hipe was + enabled, was to disable PIE build options for the VM.</p> + <p> + Own Id: OTP-14903</p> + </item> + <item> + <p>The number of driver async threads will now default to + 1 as the standard drivers do not use them anymore. Users + that changed this value to tweak the file driver should + replace <c>+A</c> with <c>+SDio</c> since it now uses + dirty IO schedulers instead of async threads.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14928</p> + </item> + <item> + <p> + Optimize <c>==</c> and <c>/=</c> for binaries with + different sizes to be constant in time instead of + proportional to the size of their common prefix.</p> + <p> + Own Id: OTP-14934 Aux Id: PR-1708 </p> + </item> + <item> + <p> + Refactorings making some internal process flags available + for other usage.</p> + <p> + Own Id: OTP-14948</p> + </item> + <item> + <p> + Removed need for HiPE to allocate native executable + memory in low 2GB address space on x86_64. Command line + option <c>+MXscs</c> is thereby obsolete and ignored.</p> + <p> + Own Id: OTP-14951</p> + </item> + <item> + <p>Added <c>enif_make_map_from_arrays</c> for creating a + populated map, analogous to + <c>enif_make_list_from_array</c>.</p> + <p> + Own Id: OTP-14954</p> + </item> + <item> + <p>Added configuration switches for busy-wait and wake up + thresholds for dirty schedulers, and changing these + settings for normal schedulers will no longer affect + dirty schedulers. </p> <p>Refer to the documentation for + details. The new switches are <seealso + marker="erl#+sbwtdcpu">+sbwtdcpu</seealso>, <seealso + marker="erl#+sbwtdio">+sbwtdio</seealso>, <seealso + marker="erl#+swtdcpu">+swtdcpu</seealso>, and <seealso + marker="erl#+swtdio">+swtdio</seealso>.</p> <p>The + default busy wait threshold for dirty scheduler threads + has also been lowered to <c>short</c>.</p> + <p> + Own Id: OTP-14959</p> + </item> + <item> + <p> + The list of "taints" now also includes dynamic loaded + drivers in addition to NIF libraries. Statically linked + drivers and NIF libraries that are part of erts are not + included. The "taints" are returned by + <c>system_info(taints)</c> and printed in the header of + <c>erl_crash.dump</c> files.</p> + <p> + Own Id: OTP-14960</p> + </item> + <item> + <p>Added <c>instrument:allocations</c> and + <c>instrument:carriers</c> for retrieving information + about memory utilization and fragmentation.</p> + <p>The old <c>instrument</c> interface has been removed, + as have the related options <c>+Mim</c> and + <c>+Mis</c>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14961</p> + </item> + <item> + <p>The process suspend functionality used by the <seealso + marker="erlang#suspend_process/2">erlang:suspend_process/2</seealso> + BIF has been reimplemented using the newly introduced + true asynchronous signaling between processes. This + mainly to reduce memory usage in the process control + block of all processes, but also in order to simplify the + implementation.</p> <warning> <p>You can easily create + deadlocks if processes suspends each other (directly or + in circles). In ERTS versions prior to ERTS version 10.0, + the runtime system prevented such deadlocks, but this + prevention has now been removed due to performance + reasons.</p> </warning> <p>Other ERTS internal + functionality that used the previous process suspend + functionality have also been reimplemented to use + asynchronous signaling instead.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14964 Aux Id: OTP-14589 </p> + </item> + <item> + <p>Added the <c>nifs</c> option to + <c>?MODULE:module_info/1</c> for listing a module's + installed NIF functions.</p> + <p> + Own Id: OTP-14965</p> + </item> + <item> + <p> + New implementation of <c>erlang:process_info/[1,2]</c>.</p> + <p> + In the general case when inspecting another process, the + new implementation sends an asynchronous process-info + request signal to the other process and waits for the + result instead of locking the other process and reading + the result directly. In some special cases where no + conflicts occur, signal order wont be violated, and the + amount of data requested is guaranteed to be small, the + inspected process may be inspected directly.</p> + <p> + Appropriate amount of reductions are now also bumped when + inspecting a process.</p> + <p> + Own Id: OTP-14966</p> + </item> + <item> + <p> + Removed process start time from crash dump in order to + save memory in process control block.</p> + <p> + Own Id: OTP-14975 Aux Id: PR-1597 </p> + </item> + <item> + <p> + Optimize <c>erlang:put/2</c> when updating existing key + with a new immediate value (atom, small integer, pid, + port).</p> + <p> + Own Id: OTP-14976</p> + </item> + <item> + <p> + <c>erlang:process_info/1</c> has been changed to no + longer include <c>messages</c> by default. Instead + <c>erlang:process_info/2</c> should be used.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14986 Aux Id: PR-1745 </p> + </item> + <item> + <p> + New <c>erlang:system_info(ets_count)</c> to get total + number of ets tables existing at the local node.</p> + <p> + Own Id: OTP-14987</p> + </item> + <item> + <p> + New NIF functions: <c>enif_mutex_name</c>, + <c>enif_cond_name</c>, <c>enif_rwlock_name</c>, + <c>enif_thread_name</c>, <c>enif_vfprintf</c>, + <c>enif_vsnprintf</c>.</p> + <p> + Own Id: OTP-14994</p> + </item> + <item> + <p>When <c>erlang:system_flag(backtrace_depth, 0)</c> has + been called, all exceptions will now contain the entry + for <em>one</em> function (despite the zero). It used to + be that a hand-made stack backtrace passed to + <c>erlang:raise/3</c> would be be truncated to an empty + list.</p> + <p> + Own Id: OTP-15026</p> + </item> + <item> + <p> + Fixed bug for named <c>ets</c> tables which could cause + unexpected results from matchspec iteration functions + (<c>ets:select*</c> and <c>ets:match*</c>) if the table + was deleted and recreated with the same name during the + iteration. The iteration could incorrectly continue + through the recreated table. The expected correct + behavior is now for the iteration call to fail with a + <c>badarg</c> exception if the table is deleted before + the iteration has completed.</p> + <p> + Own Id: OTP-15031</p> + </item> + <item> + <p>Two new guards BIFs operating on maps have been added: + <c>map_get/2</c> and <c>is_map_key/2</c>. They do the + same as <c>maps:get/2</c> and <c>maps:is_key/2</c>, + respectively, except that they are allowed to be used in + guards.</p> + <p> + Own Id: OTP-15037 Aux Id: PR-1784, PR-1802 </p> + </item> + <item> + <p> + Release run-queue lock while cleaning up terminated dirty + process.</p> + <p> + Own Id: OTP-15081</p> + </item> + <item> + <p>The callback module passed as <c>-epmd_module</c> to + erl has been expanded to be able to do name and port + resolving.</p> <p>Documentation has also been added in + the <seealso + marker="kernel:erl_epmd"><c>erl_epmd</c></seealso> + reference manual and ERTS User's Guide <seealso + marker="erts:alt_disco">How to Implement an Alternative + Service Discovery for Erlang Distribution</seealso>.</p> + <p> + Own Id: OTP-15086 Aux Id: PR-1694 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3.3.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed bug in <c>ets:select_replace</c> when called with a + fully bound key could cause a following call to + <c>ets:next</c> or <c>ets:prev</c> to crash the emulator + or return invalid result.</p> + <p> + Own Id: OTP-15346</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3.3.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a bug which caused an emulator crash when + <c>enif_send()</c> was called by a NIF that executed on a + dirty scheduler. The bug was either triggered when the + NIF called <c>enif_send()</c> without a message + environment, or when the process executing the NIF was + <c>send</c> traced.</p> + <p> + Own Id: OTP-15223</p> + </item> + <item> + <p> + Fixed a bug causing some Erlang references to be + inconsistently ordered. This could for example cause + failure to look up certain elements with references as + keys in search data structures. This bug was introduced + in R13B02.</p> + <p> + Thanks to Simon Cornish for finding the bug and supplying + a fix.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-15225</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3.3.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a race condition in the inet driver that could + cause receive to hang when the emulator was compiled with + gcc 8.</p> + <p> + Own Id: OTP-15158 Aux Id: ERL-654 </p> + </item> + <item> + <p> + Fix bug in generation of erl_crash.dump, which could + cause VM to crash.</p> + <p> + Bug exist since erts-9.2 (OTP-20.2).</p> + <p> + Own Id: OTP-15181</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3.3.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a rare bug that could cause processes to be + scheduled after they had been freed.</p> + <p> + Own Id: OTP-15067 Aux Id: ERL-573 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed bug in <c>ets</c> that could cause VM crash if + process A terminates after fixating a table and process B + deletes the table at "the same time". The table fixation + could be done with <c>ets:safe_fixtable</c> or if process + A terminates in the middle of a long running + <c>select</c> or <c>match</c> call.</p> + <p> + Own Id: OTP-15109</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed bug in <c>enif_binary_to_term</c> which could cause + memory corruption for immediate terms (atoms, small + integers, pids, ports, empty lists).</p> + <p> + Own Id: OTP-15080</p> + </item> + <item> + <p> + Fixed bug in <c>erlang:system_profile/2</c> that could + cause superfluous <c>{profile,_,active,_,_}</c> messages + for terminating processes.</p> + <p> + Own Id: OTP-15085</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a crash in <c>heart:get_cmd/0</c> when the + stored command was too long.</p> + <p> + Own Id: OTP-15034</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a <c>configure</c> test for <c>libz</c> internals + that unintentionally caused various native code in OTP to + link against <c>libz</c>. Under certain circumstances + this caused the build of OTP to fail.</p> + <p> + Own Id: OTP-14840 Aux Id: ERL-529 </p> + </item> + <item> + <p> + File names containing unicode codepoints larger than 255 + were not correctly encoded in stack traces.</p> + <p> + Own Id: OTP-14847 Aux Id: ERL-544 </p> + </item> + <item> + <p> + Fix HiPE bug for binary constructs like + <c><<X/utf8>></c> which could in rare cases + cause faulty results or VM crash.</p> + <p> + This fix affects both the <c>hipe</c> compiler and + <c>erts</c> runtime in an <em>incompatible</em> way. Old + hipe compiled files need to be recompiled to load and run + properly as native.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14850 Aux Id: PR-1664 </p> + </item> + <item> + <p> + Fix <c>term_to_binary/2</c> spec for + <c>minor_version</c>.</p> + <p> + Own Id: OTP-14876 Aux Id: ERL-548 </p> + </item> + <item> + <p> + Fix bug in erlang:binary_to_integer/2 where invalid + characters were not detected for bases larger then 10. + e.g. <c>binary_to_integer(<<":">>, 16)</c> + would return 3 and not badarg as it should.</p> + <p> + Own Id: OTP-14879</p> + </item> + <item> + <p>Fixed bug in <c>float_to_list/2</c> and + <c>float_to_binary/2</c> with option <c>decimals</c> that + caused a faulty rounding up of the last decimal digit for + about 6% of floats with a fraction part.</p> + <p>For example, <c>float_to_list(0.145, + [{decimals,1}])</c> returned <c>"0.2"</c> instead of + <c>"0.1"</c>.</p> + <p> + Own Id: OTP-14890</p> + </item> + <item> + <p> + Fix bug causing slow hipe execution in modules loaded + early during boot or loaded by <c>code:atomic_load</c> or + <c>code:finish_loading</c>.</p> + <p> + Own Id: OTP-14891</p> + </item> + <item> + <p>Fixed a buffer overflow in an internal string + formatting function that could be hit if specifying a + long floating-point format specifier to + <c>erts_sprintf</c> or similar.</p> + <p> + Own Id: OTP-14920</p> + </item> + <item> + <p><c>erlang:iolist_to_iovec/1</c> and + <c>enif_inspect_iovec</c> will no longer fail when + provided with binaries that have been matched-out on a + non-byte boundary.</p> + <p> + Own Id: OTP-14921</p> + </item> + <item> + <p><c>iolist_to_binary/1</c> and + <c>erlang:iolist_to_iovec/1</c> will now badarg if + supplied with a bitstring (without a list).</p> + <p> + Own Id: OTP-14926</p> + </item> + <item> + <p> + Reject loading modules with names containing directory + separators ('/' or '\' on Windows).</p> + <p> + Own Id: OTP-14933 Aux Id: ERL-564, PR-1716 </p> + </item> + <item> + <p> + Fix potential dead-lock when the tracer process dies + while a the traced process is running on a dirty + scheduler.</p> + <p> + Own Id: OTP-14938</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + More crash dump info such as: process binary virtual heap + stats, full info for process causing out-of-mem during + GC, more port related info, and dirty scheduler info.</p> + <p> + Own Id: OTP-14820</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.2.1</title> + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Improve search algorithm of abandoned memory carriers. + Instead of limited linear search, each allocator instance + maintain a balanced search tree of all its abandoned + carriers for faster and more exhaustive search.</p> + <p> + Own Id: OTP-14915 Aux Id: ERIERL-88 </p> + </item> + <item> + <p> + New erts_alloc command line options <c>+M_acnl</c> and + <c>+M_acfml</c> to limit carrier abandonment.</p> + <p> + Own Id: OTP-14916 Aux Id: ERIERL-88 </p> + </item> + <item> + <p> + New family of <c>erts_alloc</c> strategies: Age Order + First Fit. Similar to "address order", but instead the + oldest possible carrier is always chosen for allocation.</p> + <p> + Own Id: OTP-14917 Aux Id: ERIERL-88 </p> + </item> + <item> + <p> + Add possibility to change allocator options at runtime + with <c>system_info(erts_alloc, ...)</c>. Only option + <c>sbct</c> (single block carrier threshold) is currently + supported via this interface.</p> + <p> + Own Id: OTP-14918 Aux Id: ERIERL-88 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix a bug in tracing where the {caller} match spec + function would be set to undefined incorrectly when used + in conjunction with return_to or return_trace on some + functions.</p> + <p> + The functions effected are: erlang:put/2, erlang:erase/1, + erlang:process_info/1,2, erlang:nif_load/2, + erts_internal:garbage_collection/1 and + erts_internal:check_process_code/1.</p> + <p> + Because of this bug, the analysis done by fprof could + become incorrect when the functions above are the + tail-call in a function.</p> + <p> + Own Id: OTP-14677</p> + </item> + <item> + <p> + Fix emulator deadlock that would happen if + <c>trap_exit</c> was set to true and a process sends an + exit signal to itself using <c>exit(self(), Reason)</c> + while receive tracing was enabled for that process.</p> + <p> + Own Id: OTP-14678 Aux Id: ERL-495 </p> + </item> + <item> + <p>Writing of crash dumps is significantly faster.</p> + <p>Maps are now included in crash dumps.</p> + <p>Constants terms would only be shown in one process, + while other processes referencing the same constant term + would show a marker for incomplete heap. </p> + <p> + Own Id: OTP-14685 Aux Id: OTP-14611, OTP-14603, OTP-14595 </p> + </item> + <item> + <p> + The fallback home directory for windows has been changed + to be the PROFILE directory instead of the WINDOWS + directory. The fallback is used when the environment + variables HOMEDRIVE and HOMEPATH have not been set.</p> + <p> + Own Id: OTP-14691</p> + </item> + <item> + <p> + Fix bug for hipe compiled code using + <c><<X/utf32>></c> binary construction that + could cause faulty result or even VM crash.</p> + <p> + On architectures other than x86_64, code need to be + recompiled to benefit from this fix.</p> + <p> + Own Id: OTP-14740</p> + </item> + <item> + <p> + Fixed bug in <c>erlang:garbage_collect/2</c> and + <c>erlang:check_process_code/3</c>, when called with + option <c>{async,ReqestId}</c>. Could cause VM crash or + heap corruption if <c>RequestId</c> was an immediate term + (like a pid, atom or small integer). Bug exists since + OTP-17.0.</p> + <p> + Own Id: OTP-14752</p> + </item> + <item> + <p>ERL_NIF_MINOR_VERSION wasn't bumped with the addition + of <c>enif_ioq_*</c>.</p> + <p> + Own Id: OTP-14779</p> + </item> + <item> + <p>Purging of loaded code that contained "fake literals" + (for example the magic reference obtained from + '<c>ets:new/2</c>') would crash the runtime system. + Corrected.</p> + <p> + Own Id: OTP-14791</p> + </item> + <item> + <p>Setting the size of the atom table to a number near + 2147483647 (using the '<c>+t</c>' option) would cause the + emulator to exit with a failure to allocate a huge amount + of memory. This has been corrected. Also the usage + message for the '<c>+t</c>' option has been corrected to + show the correct upper limit 2147483647 instead of 0.</p> + <p> + Own Id: OTP-14796</p> + </item> + <item> + <p>Fixed a bug that prevented registered process names + from being resolved in lcnt results.</p> + <p> + Own Id: OTP-14803</p> + </item> + <item> + <p>Formatting bugs were fixed in several HiPE debug + BIFs.</p> + <p> + Own Id: OTP-14804</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p>Binaries and some other data in crash dumps are now + encoded in base64 (instead of in hex), which will reduce + the size of crash dumps.</p> + <p>A few bugs in the handling of sub binaries in + <c>crashdump_viewer</c> have been fixed.</p> + <p> + Own Id: OTP-14686</p> + </item> + <item> + <p> + Micro optimization for send operations of messages to + other nodes. The local ack-message, which is otherwise + sent back from TPC/IP port driver to sending client + process, is now ignored earlier for distributed send + operations.</p> + <p> + Own Id: OTP-14689</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.1.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a bug in file closure on Unix; close(2) was + retried on EINTR which could cause a different (recently + opened) file to be closed as well.</p> + <p> + Own Id: OTP-14775</p> + </item> + <item> + <p> + A race-condition when tearing down a connection with + active node monitors could cause the runtime system to + crash.</p> + <p> + This bug was introduced in ERTS version 8.0 (OTP 19.0).</p> + <p> + Own Id: OTP-14781 Aux Id: OTP-13047 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.1.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Microstate accounting sometimes produced incorrect + results for dirty schedulers.</p> + <p> + Own Id: OTP-14707</p> + </item> + <item> + <p>Fixed a regression in <c>zlib:gunzip/1</c> that + prevented it from working when the decompressed size was + a perfect multiple of 16384. This regression was + introduced in 20.1.1</p> + <p> + Own Id: OTP-14730 Aux Id: ERL-507 </p> + </item> + <item> + <p>Fixed a memory corruption bug in + <c>enif_inspect_iovec</c>; writable binaries stayed + writable after entering the iovec.</p> + <p> + Own Id: OTP-14745</p> + </item> + <item> + <p>Fixed a crash in <c>enif_inspect_iovec</c> on + encountering empty binaries.</p> + <p> + Own Id: OTP-14750</p> + </item> + <item> + <p><c>zlib:deflateParams/3</c> will no longer return + <c>buf_error</c> when called after <c>zlib:deflate/2</c> + with zlib <c>1.2.11</c>.</p> + <p> + Own Id: OTP-14751</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.1.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Added zlib:set_controlling_process/2 to move a + zstream() between processes.</p> + <p> + Own Id: OTP-14672 Aux Id: ERL-494 </p> + </item> + <item> + <p> + Fix so that schedulers are bound correctly when the first + available cpu is not the first detected cpu. e.g. when + using "taskset -c X..Y" when X is not equal to 0.</p> + <p> + Own Id: OTP-14694</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.1.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed bug that could cause a VM crash when a corrupt + message is received on distribution channel from other + node.</p> + <p> + Own Id: OTP-14661 Aux Id: ERIERL-80 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.1.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The new zlib module returned a data_error when + inflating concatenated streams, which was incompatible + with the old module's behavior of returning the + uncompressed data up to the end of the first stream.</p> + <p> + Own Id: OTP-14648</p> + </item> + <item> + <p>zlib:gunzip/1 will no longer stop at the end of the + first stream when decompressing concatenated gzip + files.</p> + <p> + Own Id: OTP-14649</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Changed <c>erlang:apply/2</c> to raise a <c>badarg</c> + exception if the second argument is not a proper list. + Previous behavior was a misleading <c>undef</c> + exception.</p> + <p> + Own Id: OTP-14490 Aux Id: ERL-432 </p> + </item> + <item> + <p>On macOS, <c>crypto</c> would crash if <c>observer</c> + had been started before <c>crypto</c>. On the beta for + macOS 10.13 (High Sierra), <c>crypto</c> would crash. + Both of those bugs have been fixed.</p> + <p> + Own Id: OTP-14499 Aux Id: ERL-251 ERL-439 </p> + </item> + <item> + <p> + Fixed bug in enif_whereis_pid/port that could cause heap + corruption in rare cases.</p> + <p> + Own Id: OTP-14523</p> + </item> + <item> + <p> + Fix so that trace messages generated when in a dirty nif + are flushed correctly when the dirty nif is done + executing.</p> + <p> + Own Id: OTP-14538</p> + </item> + <item> + <p> + Fix escape code handling when using ANSI color codes in + the shell.</p> + <p> + Own Id: OTP-14549 Aux Id: PR1536 </p> + </item> + <item> + <p> + Upgraded the ERTS internal PCRE library from version 8.40 + to version 8.41. See <url + href="http://pcre.org/original/changelog.txt">http://pcre.org/original/changelog.txt</url> + for information about changes made to PCRE. This library + implements major parts of the <seealso + marker="stdlib:re"><c>re</c></seealso> regular + expressions module.</p> + <p> + Own Id: OTP-14574</p> + </item> + <item> + <p> + Fixed a bug causing <c>statistics(runtime)</c> to produce + negative values and a bug in + <c>statistics(wall_clock)</c> causing it to produce + values one second too long.</p> + <p> + <c>statistics(runtime)</c> now also use + <c>getrusage()</c> as source when available preventing + the returned value from wrapping as frequent as before.</p> + <p> + Own Id: OTP-14597 Aux Id: ERL-465 </p> + </item> + <item> + <p> + Fixed small memory leak that could occur when sending to + a terminating port.</p> + <p> + Own Id: OTP-14609</p> + </item> + <item> + <p> + Fix bug causing VM crash when a module with + <c>-on_load</c> directive is loaded while + <c>erlang:trace(on_load, ...)</c> is enabled.</p> + <p> + Own Id: OTP-14612</p> + </item> + <item> + <p>A warning that the compiler may optimize away atoms + have been added to the documentation of + <c>list_to_existing_atom/1</c> and + <c>binary_to_existing_atom/2</c>.</p> + <p> + Own Id: OTP-14614 Aux Id: ERL-453 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p>Lock counting can now be fully toggled at runtime in + the lock counting emulator (<c>-emu_type lcnt</c>). + Everything is enabled by default to match the old + behavior, but specific categories can be toggled at will + with minimal runtime overhead when disabled. Refer to the + documentation on <c>lcnt:rt_mask/1</c> for details.</p> + <p> + Own Id: OTP-13170</p> + </item> + <item> + <p>The <c>zlib</c> module has been refactored and all its + operations will now yield appropriately, allowing them to + be used freely in concurrent applications.</p> <p>The + following functions have been deprecated, but will not + produce compiler warnings until OTP 21: + <c>zlib:adler32</c>, <c>zlib:crc32</c>, + <c>zlib:inflateChunk</c>, <c>zlib:getBufSize</c>, + <c>zlib:setBufSize</c>.</p> <p>The behavior of throwing + an error when a dictionary is required for decompression + has also been deprecated. Refer to the documentation on + <c>inflateSetDictionary/2</c> for details.</p> + <p> + Own Id: OTP-14185</p> + </item> + <item> + <p><c>lcnt:collect</c> and <c>lcnt:clear</c> will no + longer block all other threads in the runtime system.</p> + <p> + Own Id: OTP-14412</p> + </item> + <item> + <p>Add <c>erlang:iolist_to_iovec/1</c>, which converts an + iolist() to an erlang:iovec(), which suitable for use + with <c>enif_inspect_iovec</c>.</p> + <p> + Own Id: OTP-14520</p> + </item> + <item> + <p>When provided with bad arguments, the <c>zlib</c> + module will now raise named exceptions instead of just + <c>badarg</c>. For example, <c>not_initialized</c> when + using <c>zlib:inflate/2</c> with an uninitialized + stream.</p> + <p> + Own Id: OTP-14527</p> + </item> + <item> + <p> + <c>erlang:halt/2</c> allows any Unicode string as slogan + for the crash dump.</p> + <p> + Own Id: OTP-14553</p> + </item> + <item> + <p>Add new nif API functions for managing an I/O Queue. + The added functions are:</p> <list type="bulleted"> + <item><seealso marker="erl_nif#enif_ioq_create"> + <c>enif_ioq_create()</c></seealso></item> <item><seealso + marker="erl_nif#enif_ioq_destroy"> + <c>enif_ioq_destroy()</c></seealso></item> <item><seealso + marker="erl_nif#enif_ioq_enq_binary"> + <c>enif_ioq_enq_binary()</c></seealso></item> + <item><seealso marker="erl_nif#enif_ioq_enqv"> + <c>enif_ioq_enqv()</c></seealso></item> <item><seealso + marker="erl_nif#enif_ioq_deq"> + <c>enif_ioq_deq()</c></seealso></item> <item><seealso + marker="erl_nif#enif_ioq_peek"> + <c>enif_ioq_peek()</c></seealso></item> <item><seealso + marker="erl_nif#enif_inspect_iovec"> + <c>enif_inspect_iovec()</c></seealso></item> + <item><seealso marker="erl_nif#enif_free_iovec"> + <c>enif_free_iovec()</c></seealso></item> </list> + <p> + Own Id: OTP-14598</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.0.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed bug in <c>binary_to_term</c> and + <c>binary_to_atom</c> that could cause VM crash. + Typically happens when the last character of an UTF8 + string is in the range 128 to 255, but truncated to only + one byte. Bug exists in <c>binary_to_term</c> since ERTS + version 5.10.2 (OTP_R16B01) and <c>binary_to_atom</c> + since ERTS version 9.0 (OTP-20.0).</p> + <p> + Own Id: OTP-14590 Aux Id: ERL-474 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.0.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A timer internal bit-field used for storing scheduler id + was too small. As a result, VM internal timer data + structures could become inconsistent when using 1024 + schedulers on the system. Note that systems with less + than 1024 schedulers are not effected by this bug.</p> + <p> + This bug was introduced in ERTS version 7.0 (OTP 18.0).</p> + <p> + Own Id: OTP-14548 Aux Id: OTP-11997, ERL-468 </p> + </item> + <item> + <p> + Automatic cleanup of a BIF timer, when the owner process + terminated, could race with the timeout of the timer. + This could cause the VM internal data structures to + become inconsistent which very likely caused a VM crash.</p> + <p> + This bug was introduced in ERTS version 9.0 (OTP 20.0).</p> + <p> + Own Id: OTP-14554 Aux Id: OTP-14356, ERL-468 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.0.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Binary append operations did not check for overflow, + resulting in nonsensical results when huge binaries were + appended.</p> + <p> + Own Id: OTP-14524</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.0.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Added missing release notes for OTP-14491 ("performance + bug in pre-allocators") which was included in erts-9.0.1 + (OTP-20.0.1).</p> + <p> + Own Id: OTP-14494</p> + </item> + <item> + <p>Fixed a bug that prevented TCP sockets from being + closed properly on send timeouts.</p> + <p> + Own Id: OTP-14509</p> + </item> + <item> + <p> + Fixed bug in operator <c>bxor</c> causing erroneuos + result when one operand is a big <em>negative</em> + integer with the lowest <c>N*W</c> bits as zero and the + other operand not larger than <c>N*W</c> bits. <c>N</c> + is an integer of 1 or larger and <c>W</c> is 32 or 64 + depending on word size.</p> + <p> + Own Id: OTP-14514</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 9.0.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a bug in gen_tcp:send where it never returned when + repeatedly called on a remotely closed TCP socket.</p> + <p> + Own Id: OTP-13939 Aux Id: ERL-193 </p> + </item> + <item> + <p> + Fixed segfault that could happen during cleanup of + aborted erlang:port_command/3 calls. A port_command is + aborted if the port is closed at the same time as the + port_command was issued. This bug was introduced in + erts-8.0.</p> + <p> + Own Id: OTP-14481</p> + </item> + <item> + <p> + Fixed implementation of <c>statistics(wall_clock)</c> and + <c>statistics(runtime)</c> so that values do not + unnecessarily wrap due to the emulator. Note that the + values returned by <c>statistics(runtime)</c> may still + wrap due to limitations in the underlying functionality + provided by the operating system.</p> + <p> + Own Id: OTP-14484</p> + </item> + <item> + <p> + Fix performance bug in pre-allocators that could cause + them to permanently fall back on normal more expensive memory + allocation. Pre-allocators are used for quick allocation + of short lived meta data used by messages and other + scheduled tasks. Bug exists since OTP_R15B02. + [this release note was missing in erts-9.0.1]</p> + <p> + Own Id: OTP-14491</p> + </item> + </list> + </section> + +</section> + +<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>When an exception such as '<c>throw(HugeTerm)</c>' was + caught, <c>HugeTerm</c> term would be kept in the process + until the next exception occurred, potentially increasing + the heap size for the process. That has been + corrected.</p> + <p> + Own Id: OTP-14255 Aux Id: OTP-14400, OTP-14401 </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 reallocated by the + <c>enif_copy</c> call when it shouldn't have been.</p> + <p> + Own Id: OTP-14304</p> + </item> + <item> + <p> + The address family <c>local</c> (AF_UNIX / AF_LOCAL) now + does not ensure zero termination of Linux Abstract + Addresses so they can use all bytes.</p> + <p> + Own Id: OTP-14305</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> + <item> + <p> + Fix bug causing <c>code:is_module_native</c> to falsely + return true when <c>local</c> call trace is enabled for + the module.</p> + <p> + Own Id: OTP-14390</p> + </item> + <item> + <p> + Fix emulator crash when receive tracing on a + <c>trace_delivered</c> message.</p> + <p> + Own Id: OTP-14411</p> + </item> + <item> + <p> + Fix file:sendfile error handling on SunOS when a + connection is closed during transmission.</p> + <p> + Own Id: OTP-14424</p> + </item> + <item> + <p> + <c>escript</c> did not handle paths with spaces correct.</p> + <p> + Own Id: OTP-14433</p> + </item> + <item> + <p> + Fix erroneous lock check assertion when <c>wx</c> is run + on MacOS X.</p> + <p> + Own Id: OTP-14437 Aux Id: ERL-360 </p> + </item> + <item> + <p>Active-mode TCP sockets are now cleaned up properly on + send/shutdown errors.</p> + <p> + Own Id: OTP-14441 Aux Id: ERL-430 </p> + </item> + <item> + <p> + Fix compilation of hipe_mkliterals when the LIBS + configure variable had to be set.</p> + <p> + Own Id: OTP-14447</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 major + 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 implements 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/1"><c>erlang:statistics/1</c></seealso> + with arguments inspecting scheduler and run queue states + have been changed due to the dirty scheduler support. + Code using this functionality may have to be rewritten + taking these incompatibilities into consideration. + Examples of such uses are calls to <seealso + marker="erts:erlang#statistics_scheduler_wall_time"><c>erlang:statistics(scheduler_wall_time)</c></seealso>, + <seealso + marker="erts:erlang#statistics_total_run_queue_lengths"><c>statistics(total_run_queue_lengths)</c></seealso>, + <seealso + marker="erts:erlang#statistics_total_active_tasks"><c>statistics(total_active_tasks)</c></seealso>, + etc.</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 preparation 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">http://pcre.org/original/changelog.txt</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 + in the distribution between erlang nodes, + <c>erl_interface</c>, and <c>jinterface</c>. 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> + Atoms that can be encoded using latin1 are still encoded + by <c>term_to_binary()</c> using latin1 encoding. Note + that all atoms will by default be encoded using utf8 in a + future Erlang/OTP release. For more information see the + documentation of <seealso + marker="erts:erlang#term_to_binary/2"><c>erlang:term_to_binary/2</c></seealso>.</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> + 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> + <item> + <p>'<c>./configure --enable-lock-counter</c>' will + enabling building of an additional emulator that has + support for lock counting. (The option previously + existed, but would turn on lock counting in the default + emulator being built.) To start the lock-counting + emulator, use '<c>erl -emu_type lcnt</c>'.</p> + <p>On Windows, <c>erl</c> recognized the undocumented + option <c>-debug</c> for starting a debug-compiled + emulator. That option has been removed. Use '<c>erl + -emu_type debug</c>' instead.</p> + <p> + Own Id: OTP-14407</p> + </item> + <item> + <p> + Warnings have been added to the relevant documentation + about not using un-secure distributed nodes in exposed + environments.</p> + <p> + Own Id: OTP-14425</p> + </item> + <item> + <p> + Improvement of the documentation of the environment + variable <c>ERL_CRASH_DUMP_SECONDS</c> as well as the + default behavior when it is not set.</p> + <p> + Own Id: OTP-14434</p> + </item> + <item> + <p> + Enabled off-heap message queue for some system processes + that might receive large amounts of messages.</p> + <p> + Own Id: OTP-14438</p> + </item> + <item> + <p>ETS lock indexes have been replaced with the table + name in LCNT results.</p> + <p> + Own Id: OTP-14442 Aux Id: ERIERL-22 </p> + </item> + <item> + <p> + Introduced the new functions <seealso + marker="erl_nif#enif_whereis_pid"><c>enif_whereis_pid()</c></seealso> + and <seealso + marker="erl_nif#enif_whereis_port"><c>enif_whereis_port()</c></seealso>.</p> + <p> + Own Id: OTP-14453 Aux Id: PR-1400 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.5.6</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed small memory leak that could occur when sending to + a terminating port.</p> + <p> + Own Id: OTP-14609 Aux Id: ERIERL-238 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.5.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a race condition in the inet driver that could + cause receive to hang when the emulator was compiled with + gcc 8.</p> + <p> + Own Id: OTP-15158 Aux Id: ERL-654 </p> + </item> + <item> + <p> + Fixed a bug causing some Erlang references to be + inconsistently ordered. This could for example cause + failure to look up certain elements with references as + keys in search data structures. This bug was introduced + in R13B02.</p> + <p> + Thanks to Simon Cornish for finding the bug and supplying + a fix.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-15225</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.5.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a bug in file closure on Unix; close(2) was + retried on EINTR which could cause a different (recently + opened) file to be closed as well.</p> + <p> + Own Id: OTP-14775</p> + </item> + <item> + <p> + A race-condition when tearing down a connection with + active node monitors could cause the runtime system to + crash.</p> + <p> + This bug was introduced in ERTS version 8.0 (OTP 19.0).</p> + <p> + Own Id: OTP-14781 Aux Id: OTP-13047 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.5.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A timer internal bit-field used for storing scheduler id + was too small. As a result, VM internal timer data + structures could become inconsistent when using 1024 + schedulers on the system. Note that systems with less + than 1024 schedulers are not effected by this bug.</p> + <p> + This bug was introduced in ERTS version 7.0 (OTP 18.0).</p> + <p> + Own Id: OTP-14548 Aux Id: OTP-11997, ERL-468 </p> + </item> + <item> + <p> + Fixed bug in <c>binary_to_term</c> and + <c>binary_to_atom</c> that could cause VM crash. + Typically happens when the last character of an UTF8 + string is in the range 128 to 255, but truncated to only + one byte. Bug exists in <c>binary_to_term</c> since ERTS + version 5.10.2 (OTP_R16B01) and <c>binary_to_atom</c> + since ERTS version 9.0 (OTP-20.0).</p> + <p> + Own Id: OTP-14590 Aux Id: ERL-474 </p> + </item> + <item> + <p> + Fix bug causing VM crash when a module with + <c>-on_load</c> directive is loaded while + <c>erlang:trace(on_load, ...)</c> is enabled.</p> + <p> + Own Id: OTP-14612</p> + </item> + <item> + <p> + Fixed bug that could cause a VM crash when a corrupt + message is received on distribution channel from other + node.</p> + <p> + Own Id: OTP-14661 Aux Id: ERIERL-80 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.5.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix performance bug in pre-allocators that could cause + them to permanently fall back on normal more expensive + memory allocation. Pre-allocators are used for quick + allocation of short lived meta data used by messages and + other scheduled tasks. Bug exists since OTP_R15B02.</p> + <p> + Own Id: OTP-14491</p> + </item> + <item> + <p>Fixed a bug that prevented TCP sockets from being + closed properly on send timeouts.</p> + <p> + Own Id: OTP-14509</p> + </item> + <item> + <p> + Fixed bug in operator <c>bxor</c> causing erroneuos + result when one operand is a big <em>negative</em> + integer with the lowest <c>N*W</c> bits as zero and the + other operand not larger than <c>N*W</c> bits. <c>N</c> + is an integer of 1 or larger and <c>W</c> is 32 or 64 + depending on word size.</p> + <p> + Own Id: OTP-14514</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.5.1</title> + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a bug in gen_tcp:send where it never returned when + repeatedly called on a remotely closed TCP socket.</p> + <p> + Own Id: OTP-13939 Aux Id: ERL-193 </p> + </item> + <item> + <p> + Fixed segfault that could happen during cleanup of + aborted erlang:port_command/3 calls. A port_command is + aborted if the port is closed at the same time as the + port_command was issued. This bug was introduced in + erts-8.0.</p> + <p> + Own Id: OTP-14481</p> + </item> + <item> + <p> + Fixed implementation of <c>statistics(wall_clock)</c> and + <c>statistics(runtime)</c> so that values do not + unnecessarily wrap due to the emulator. Note that the + values returned by <c>statistics(runtime)</c> may still + wrap due to limitations in the underlying functionality + provided by the operating system.</p> + <p> + Own Id: OTP-14484</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Active-mode TCP sockets are now cleaned up properly on + send/shutdown errors.</p> + <p> + Own Id: OTP-14441 Aux Id: ERL-430 </p> + </item> + <item> + <p> + A code purge operation could under certain circumstances + expand the size of hibernated processes.</p> + <p> + Own Id: OTP-14444 Aux Id: ERIERL-24 </p> + </item> + <item> + <p> + Fix so that the ERL_ZZ_SIGTERM_KILL introduced in + erts-8.3.4 works.</p> + <p> + Own Id: OTP-14451</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Add option to make SIGTERM trigger the OS default + behaviour instead of doing a gracefull shutdown. To + activate this bahviour the environment variable + ERL_ZZ_SIGTERM_KILL should be set to "true". This option + only works in OTP 19 as OTP 20 will have a different way + to deal with SIGTERM.</p> + <p> + Own Id: OTP-14418 Aux Id: ERIERL-15 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <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> + <item> + <p> + Fix release note for OTP-14290 in ERTS version 8.3.1. It + was erroneously placed under "Known Bugs and Problems".</p> + <p> + Own Id: OTP-14363 Aux Id: OTP-14290 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + The <c>+Bi</c> command line argument of <c>erl</c> + erroneously caused <c>SIGTERM</c> to be ignored by the VM + as well as of all its child processes. This bug was + introduced in erts version 8.3.</p> + <p> + Own Id: OTP-14358 Aux Id: OTP-14085 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Invoking <c>init:stop/0</c> via the SIGTERM signal, in a + non-SMP BEAM, could cause BEAM to terminate with fatal + error. This has now been fixed and the BEAM will + terminate normally when SIGTERM is received.</p> + <p> + Own Id: OTP-14290</p> + </item> + <item> + <p> + Trying to open a directory with file:read_file/1 on Unix + leaked a file descriptor. This bug has now been fixed.</p> + <p> + Own Id: OTP-14308 Aux Id: ERL-383 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a number of bugs that caused faulty stack-traces + to be generated. The faulty stack traces were generated + either when applying the following functions or tracing + the following functions:</p> <list> + <item><c>erlang:error/1</c></item> + <item><c>erlang:error/2</c></item> + <item><c>erlang:exit/1</c></item> + <item><c>erlang:throw/1</c></item> </list> + <p> + Own Id: OTP-14055</p> + </item> + <item> + <p> + Corrected documentation about memory footprint for maps.</p> + <p> + Own Id: OTP-14118</p> + </item> + <item> + <p> + Fix <c>process_info(Pid, current_stacktrace)</c> to use + stack depth limit set by + <c>system_flag(backtrace_depth)</c>. The old behavior was + a hard coded depth limit of 8.</p> + <p> + Own Id: OTP-14119 Aux Id: PR-1263 </p> + </item> + <item> + <p> + A process calling <seealso + marker="erlang#system_flag_multi_scheduling"><c>erlang:system_flag(multi_scheduling, + block)</c></seealso> could end up hanging forever in the + call.</p> + <p> + Own Id: OTP-14121</p> + </item> + <item> + <p>Dirty scheduler bug fixes:</p> <list> <item><p>Fixed + call time tracing of process being scheduled on dirty + scheduler.</p></item> <item><p>GC info from dirty + schedulers.</p></item> <item><p>Multi scheduling block + with dirty schedulers could crash the runtime + system.</p></item> <item><p>Process structures could be + removed prematurely.</p></item> <item><p>GC on dirty + scheduler could crash the runtime system.</p></item> + <item><p>Termination of a process executing on a dirty + scheduler could cause a runtime system crash.</p></item> + </list> + <p> + Own Id: OTP-14122</p> + </item> + <item> + <p> + Fixed crash that occurred when writing timer data to a + crash dump.</p> + <p> + Own Id: OTP-14133</p> + </item> + <item> + <p> + A literal area could be removed while still referred from + processes.</p> + <p> + Own Id: OTP-14134</p> + </item> + <item> + <p> + Fixed a bug in the garbage collector that could crash the + runtime system.</p> + <p> + Own Id: OTP-14135</p> + </item> + <item> + <p> + Fixed a bug in call-time trace for NIFs which caused + tracing to erroneously be started multiple times for one + call.</p> + <p> + Own Id: OTP-14136</p> + </item> + <item> + <p> + Remove a debug printout and an unnecessary garbage + collection when handling exceptions in hipe compiled + code.</p> + <p> + Own Id: OTP-14153</p> + </item> + <item> + <p> + Fix bug in tracing of garbage collection that could cause + VM crash. Bug exists since OTP 19.0.</p> + <p> + Own Id: OTP-14154</p> + </item> + <item> + <p> + Fix bug in <c>binary_to_term</c> for binaries created by + <c>term_to_binary </c> with option <c>compressed</c>. The + bug can cause <c>badarg</c> exception for a valid binary + when Erlang VM is linked against a <c>zlib</c> library of + version 1.2.9 or newer. Bug exists since OTP 17.0.</p> + <p> + Own Id: OTP-14159 Aux Id: ERL-340 </p> + </item> + <item> + <p> + Fix suspension of schedulers when generating a crashdump.</p> + <p> + Own Id: OTP-14164</p> + </item> + <item> + <p>NIF resources was not handled in a thread-safe manner + in the runtime system without SMP support.</p> + <p>As a consequence of this fix, the following driver + functions are now thread-safe also in the runtime system + without SMP support:</p> <list> + <item><p><c>driver_free_binary()</c></p></item> + <item><p><c>driver_realloc_binary()</c></p></item> + <item><p><c>driver_binary_get_refc()</c></p></item> + <item><p><c>driver_binary_inc_refc()</c></p></item> + <item><p><c>driver_binary_dec_refc()</c></p></item> + </list> + <p> + Own Id: OTP-14202</p> + </item> + <item> + <p> + Fix <c>erlang:round/1</c> for large floating point + numbers with an odd absolute value between <c>(1 bsl + 52)</c> and <c>(1 bsl 53)</c>. The result was falsely + calculated as the next higher even number even though all + integer values up to <c>(1 bsl 53)</c> can be represented + as floats with full precision.</p> + <p> + Own Id: OTP-14227</p> + </item> + <item> + <p> + Add size of literals to module code size in crash dump + and <c>(l)oaded</c> command in break menu like it used to + be before OTP-19.0.</p> + <p> + Own Id: OTP-14228</p> + </item> + <item> + <p> + Fix potential bug in <c>enif_send</c> when called without + a process context and with argument <c>msg_env</c> as + <c>NULL</c>.</p> + <p> + Own Id: OTP-14229</p> + </item> + <item> + <p> + Fix bug where passing an appendable binary to + <c>erlang:port_control()</c> could crash the emulator.</p> + <p> + Own Id: OTP-14231</p> + </item> + <item> + <p> + Receive expressions with timeout in the Erlang shell + could cause a VM crash.</p> + <p> + Own Id: OTP-14241 Aux Id: ERL-365 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + A received SIGTERM signal to beam will generate a + <c>'stop'</c> message to the <c>init</c> process and + terminate the Erlang VM nicely. This is equivalent to + calling <c>init:stop/0</c>.</p> + <p> + Own Id: OTP-14085</p> + </item> + <item> + <p> + Workaround for buggy Android implementation of + <c>PTHREAD_STACK_MIN</c> causing build of runtime system + to crash on undeclared <c>PAGE_SIZE</c>.</p> + <p> + Own Id: OTP-14165 Aux Id: ERL-319 </p> + </item> + <item> + <p> + Add configure option --without-thread-names that removes + the naming of individual emulator threads.</p> + <p> + Own Id: OTP-14234</p> + </item> + <item> + <p> + Add warning in documentation of <c>zlib:deflateInit/6</c> + about option <c>WindowsBits</c> values 8 and -8.</p> + <p> + Own Id: OTP-14254 Aux Id: ERL-362 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.2.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix bug in <c>binary_to_term</c> for binaries created by + <c>term_to_binary </c> with option <c>compressed</c>. The + bug can cause <c>badarg</c> exception for a valid binary + when Erlang VM is linked against a <c>zlib</c> library of + version 1.2.9 or newer. Bug exists since OTP 17.0.</p> + <p> + Own Id: OTP-14159 Aux Id: ERL-340 </p> + </item> + <item> + <p> + The driver efile_drv when opening a file now use fstat() + on the open file instead of stat() before opening, if + fstat() exists. This avoids a race when the file happens + to change between stat() and open().</p> + <p> + Own Id: OTP-14184 Aux Id: seq-13266 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.2.1</title> + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix a quite rare bug causing VM crash during code loading + and the use of export funs (fun M:F/A) of not yet loaded + modules. Requires a very specfic timing of concurrent + scheduler threads. Has been seen on ARM but can probably + also occure on other architectures. Bug has existed since + OTP R16.</p> + <p> + Own Id: OTP-14144 Aux Id: seq13242 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed <c>configure</c> failures on MacOSX. Most important + <c>clock_gettime()</c> was detected when building for + MacOSX - El Capitan using XCode 8 despite it is not + available until MacOSX - Sierra.</p> + <p> + Own Id: OTP-13904 Aux Id: ERL-256 </p> + </item> + <item> + <p> + <c>code:add_pathsa/1</c> and command line option + <c>-pa</c> both revert the given list of directories when + adding it at the beginning of the code path. This is now + documented.</p> + <p> + Own Id: OTP-13920 Aux Id: ERL-267 </p> + </item> + <item> + <p> + Fix a compilation error of erts in OpenBSD related to the + usage of the __errno variable.</p> + <p> + Own Id: OTP-13927</p> + </item> + <item> + <p> + Fixed so that when enabling tracing on a process that had + an invalid tracer associated with it, the new tracer + overwrites the old tracer. Before this fix, calling + erlang:trace/3 would behave as if the tracer was still + alive and not apply the new trace.</p> + <p> + This fault was introduced in ERTS 8.0.</p> + <p> + Own Id: OTP-13928</p> + </item> + <item> + <p> + Fix parsing of <c>-profile_boot 'true' | 'false'</c></p> + <p> + Own Id: OTP-13955 Aux Id: ERL-280 </p> + </item> + <item> + <p> + A slight improvement of <c>erlang:get_stacktrace/0</c> + for exceptions raised in hipe compiled code. Beam + compiled functions in such stack trace was earlier + replaced by some unrelated function. They are now instead + omitted. This is an attempt to reduce the confusion in + the absence of a complete and correct stack trace for + mixed beam and hipe functions.</p> + <p> + Own Id: OTP-13992</p> + </item> + <item> + <p> Correct type declaration of match specification head. + </p> + <p> + Own Id: OTP-13996</p> + </item> + <item> + <p> + HiPE code loading failed for x86_64 if gcc was configured + with <c>--enable-default-pie</c>. Fixed by disabling PIE, + if needed for HiPE, when building the VM.</p> + <p> + Own Id: OTP-14031 Aux Id: ERL-294, PR-1239 </p> + </item> + <item> + <p> + Faulty arguments could be presented on exception from a + NIF that had rescheduled itself using + <c>enif_schedule_nif()</c>.</p> + <p> + Own Id: OTP-14048</p> + </item> + <item> + <p> + The runtime system could crash if a garbage collection on + a process was performed immediately after a NIF had been + rescheduled using <c>enif_schedule_nif()</c>.</p> + <p> + Own Id: OTP-14049</p> + </item> + <item> + <p> + A reference to purged code could be left undetected by + the purge operation if a process just had rescheduled a + NIF call using <c>enif_schedule_nif()</c> when the + process was checked. This could cause a runtime system + crash.</p> + <p> + Own Id: OTP-14050</p> + </item> + <item> + <p>Fixed a number of dirty scheduler related bugs:</p> + <list> <item><p>Process priority was not handled correct + when scheduling on a dirty scheduler.</p></item> + <item><p>The runtime system could crash when an exit + signal with a compound exit reason was sent to a process + executing on a dirty scheduler.</p></item> <item><p>The + runtime system crashed when call tracing a process + executing on a dirty scheduler.</p></item> <item><p>A + code purge operation could end up hanging forever when a + process executed on a dirty scheduler</p></item> </list> + <p> + Own Id: OTP-14051</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Fix minor soft purge race bug that could incorrectly + trigger code_server to load new code for the module if + the soft purge failed and no current version of the + module existed.</p> + <p> + Own Id: OTP-13925</p> + </item> + <item> + <p> + To ease troubleshooting, <c>erlang:load_nif/2</c> now + includes the return value from a failed call to + load/reload/upgrade in the text part of the error tuple. + The <c>crypto</c> NIF makes use of this feature by + returning the source line where/if the initialization + fails.</p> + <p> + Own Id: OTP-13951</p> + </item> + <item> + <p> + New environment variable <c>ERL_CRASH_DUMP_BYTES</c> can + be used to limit the size of crash dumps. If the limit is + reached, crash dump generation is aborted and the + generated file will be truncated.</p> + <p> + Own Id: OTP-14046</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.1.1.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A code purge operation could under certain circumstances + expand the size of hibernated processes.</p> + <p> + Own Id: OTP-14444 Aux Id: ERIERL-24 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.1.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + The emulator got a dynamic library dependency towards + libsctp, which on Linux was not intended since the + emulator there loads and resolves the needed sctp + functions in runtime. This has been fixed and a configure + switch --enable-sctp=lib has been added for those who + want such a library dependency.</p> + <p> + Own Id: OTP-13956 Aux Id: ERL-262, ERL-133 </p> + </item> + <item> + <p> + Fix SIGUSR1 crashdump generation</p> + <p> + Do not generate a core when a crashdump is asked for.</p> + <p> + Own Id: OTP-13997</p> + </item> + <item> + <p>The new functions in <c>code</c> that allows loading + of many modules at once had a performance problem. While + executing a helper function in the <c>erl_prim_loader</c> + process, garbage messages were produced. The garbages + messages were ignored and ultimately discarded, but there + would be a negative impact on performance and memory + usage. The number of garbage message depended on both the + number of modules to be loaded and the length of the code + path.</p> + <p>The functions affected of this problem were: + <c>atomic_load/1</c>, <c>ensure_modules_loaded/1</c>, and + <c>prepare_loading/1</c>.</p> + <p> + Own Id: OTP-14009</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix bug for calls from hipe code to BIFs that disable GC + while yielding. Has been causing Dialyzer crashes on ARM + (and presumably all other non-intel platforms).</p> + <p> + Own Id: OTP-13724 Aux Id: PR-1116 </p> + </item> + <item> + <p> + Fix a bug where changing the current working directory of + the VM would not change the current working directory of + programs spawned using <c>erlang:open_port({spawn,""}, + ...)</c>.</p> + <p> + Own Id: OTP-13733 Aux Id: ERL-175 </p> + </item> + <item> + <p> + Fix a bug where disabling tracing from a process that had + return_to tracing enabled and was tracing on + <c>erlang:trace/3</c> would cause a segmentation fault.</p> + <p> + Own Id: OTP-13734</p> + </item> + <item> + <p> + Update all erts documentation to use simpler English, use + consistent terminology and be easier to navigate.</p> + <p> + Own Id: OTP-13740</p> + </item> + <item> + <p> + Add dirty schedulers to the microstate accounting + statistics.</p> + <p> + Own Id: OTP-13744</p> + </item> + <item> + <p> + Fixed dirty scheduler build support on 32-bit windows.</p> + <p> + Own Id: OTP-13759</p> + </item> + <item> + <p> + inet:getstat(Socket) on an SCTP socket returned 0 for + send stats. This bug has now been corrected. Reported by + systra as issue ERL-102 on bugs.erlang.org.</p> + <p> + Own Id: OTP-13773 Aux Id: ERL-102 </p> + </item> + <item> + <p> + AF_UNSPEC and unknown address families were misread by + UDP receive in prim_inet resulting in an exception. This + bug has now been corrected.</p> + <p> + Own Id: OTP-13775</p> + </item> + <item> + <p> + Sweep HiPE stack for literals during code purge.</p> + <p> + Own Id: OTP-13777 Aux Id: PR-1122 </p> + </item> + <item> + <p> + Fix bug in run_erl for OpenBSD that could cause it on + rare occations to exit without starting the program (erl) + at all.</p> + <p> + Own Id: OTP-13795</p> + </item> + <item> + <p> + Update build scripts to not make assumtions about where + env, cp and perl are located.</p> + <p> + Own Id: OTP-13800</p> + </item> + <item> + <p> + Fixed a bug where init:stop could deadlock if a process + with infinite shutdown timeout (e.g. a supervisor) + attempted to load code while terminating.</p> + <p> + Own Id: OTP-13802</p> + </item> + <item> + <p> + Fixed a segmentation fault on sparc CPUs when free'ing a + tracer module's state.</p> + <p> + Own Id: OTP-13803</p> + </item> + <item> + <p> + <c>fun</c>s was not properly handled during purge of a + module. This could cause a crash of the VM after a purge + of a module.</p> + <p> + Own Id: OTP-13809</p> + </item> + <item> + <p> + Fixed a memory leak when the process monitoring a port + crashed.</p> + <p> + Own Id: OTP-13818</p> + </item> + <item> + <p> + Fixed multiple dirty scheduler related tracing bugs.</p> + <p> + Own Id: OTP-13822</p> + </item> + <item> + <p> + Fix error handling in beam code runtime loader for a + number of cases when index and size fields got corrupted + (negative) values.</p> + <p> + Own Id: OTP-13848 Aux Id: ERL-216 </p> + </item> + <item> + <p> + Minor fix of dirty scheduler implementation.</p> + <p> + Own Id: OTP-13852</p> + </item> + <item> + <p> + Calls to <c>erl_drv_send_term()</c> or + <c>erl_drv_output_term()</c> from a non-scheduler thread + while the corresponding port was invalid caused the + emulator to enter an inconsistent state which eventually + caused an emulator crash.</p> + <p> + Own Id: OTP-13866</p> + </item> + <item> + <p> + Fix a rare race condition in <c>erlang:open_port({spawn, + ""}, ...)</c> that would result in the erl_child_setup + program aborting and cause the emulator to exit.</p> + <p> + Own Id: OTP-13868</p> + </item> + <item> + <p>Driver and NIF operations accessing processes or ports + could cause an emulator crash when used from + non-scheduler threads. Those operations are:</p> <list> + <item><c>erl_drv_send_term()</c></item> + <item><c>driver_send_term()</c></item> + <item><c>erl_drv_output_term()</c></item> + <item><c>driver_output_term()</c></item> + <item><c>enif_send()</c></item> + <item><c>enif_port_command()</c></item> </list> + <p> + Own Id: OTP-13869</p> + </item> + <item> + <p> + Fix start scripts generation dependency in Makefile</p> + <p> + Own Id: OTP-13871 Aux Id: ERL-241 </p> + </item> + <item> + <p> + The VM could crash if <c>erlang:get_stacktrace()</c> was + called after a rescheduled NIF had thrown an exception.</p> + <p> + Own Id: OTP-13877</p> + </item> + <item> + <p>Calling <c>code:delete/1</c> before a loading a module + with an on_load function, the old code would be + overwritten, causing a memory or a crash if NIFs were + involved. (Thanks to vans163 for reporting this bug.)</p> + <p> + Own Id: OTP-13893 Aux Id: ERL-240 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Improved accuracy of timeouts on MacOS X. This by setting + premature timeouts followed by a short actual timeout + during scheduler wait.</p> + <p> + Own Id: OTP-13698</p> + </item> + <item> + <p>Added the following symbolic time unit representations + to the <seealso + marker="erlang#type-time_unit"><c>erlang:time_unit()</c></seealso> + type:</p> <list> <item><c>second</c></item> + <item><c>millisecond</c></item> + <item><c>microsecond</c></item> + <item><c>nanosecond</c></item> </list> <p>The following + symbolic time unit representations are now + <em>deprecated</em>, but still part of the + <c>erlang:time_unit()</c> type:</p> <list> + <item><c>seconds</c></item> + <item><c>milli_seconds</c></item> + <item><c>micro_seconds</c></item> + <item><c>nano_seconds</c></item> </list> + <p> + Own Id: OTP-13735</p> + </item> + <item> + <p> + Fix maps hashing entropy of maps with maps keys.</p> + <p> + Own Id: OTP-13763 Aux Id: ERL-199 </p> + </item> + <item> + <p> + Improved dirty scheduler support. A purge of a module can + now be performed without having to wait for completion of + all ongoing dirty NIF calls.</p> + <p> + Note that when enabling support for dirty schedulers, a + new purge strategy will as of ERTS version 8.1 be + enabled. This new strategy is not fully backwards + compatible with the strategy used by default. 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> + Own Id: OTP-13808 Aux Id: OTP-13833 </p> + </item> + <item> + <p> + A new purge strategy has been introduced. The new + strategy will by default be disabled during the OTP 19 + release, but will be the only strategy available as of + the OTP 20 release.</p> + <p> + The new strategy is slightly incompatible with the + strategy being used by default in OTP 19. Using the + default strategy, processes holding <c>fun</c>s that + refer to the module being purged either fail a soft + purge, or will be 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> + The new strategy can optionally be enabled when building + OTP during OTP 19, and will automatically be enabled if + the runtime system is built with support for dirty + schedulers.</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> + Own Id: OTP-13833</p> + </item> + <item> + <p> + Fixed unnecessary overestimation of heap size need during + garbage collection.</p> + <p> + Own Id: OTP-13851</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.0.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a VM crash that occurred in a garbage collection of + a process when it had received binaries. This bug was + introduced in ERTS version 8.0 (OTP 19.0).</p> + <p> + Own Id: OTP-13890</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.0.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a VM crash that occurred in garbage collection of a + process when it had received maps over the distribution. + This bug was introduced in ERTS version 8.0 (OTP 19.0).</p> + <p> + Own Id: OTP-13889</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.0.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fixed a race that could cause a lost wakeup of a process + that timed out in a <c>receive ... after</c>. This bug + was introduced in ERTS version 7.0.</p> + <p> + Own Id: OTP-13798 Aux Id: OTP-11997 </p> + </item> + <item> + <p> + Fixed segfault after writing an erl crash dump.</p> + <p> + Own Id: OTP-13799</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.0.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix scheduler deadlock bug in <c>ets:update_counter/4</c> + when key is not found and inserting the default object + causes the table to grow.</p> + <p> + Own Id: OTP-13731 Aux Id: ERL-188 </p> + </item> + <item> + <p> + Fix VM abort "Overrun stack and heap" in garbage + collection triggered by a <c>bsl</c> operation and some + very specific heap conditions.</p> + <p> + Own Id: OTP-13732 Aux Id: seq13142 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.0.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A memory allocation bug in <c>group_leader/2</c> could + cause an emulator crash when garbage collecting a process + that had been assigned a remote group leader. This bug + was introduced in ERTS version 8.0.</p> + <p> + Own Id: OTP-13716</p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 8.0</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The handling of <c>on_load</c> functions has been + improved. The major improvement is that if a code upgrade + fails because the <c>on_load</c> function fails, the + previous version of the module will now be retained.</p> + <p> + Own Id: OTP-12593</p> + </item> + <item> + <p><c>is_builtin(erlang, apply, 3)</c> will now return + <c>true</c>.</p> + <p> + Own Id: OTP-13034</p> + </item> + <item> + <p> + Fix <c>enif_get_list_length</c> to return false if list + is improper or have length larger than <c>UINT_MAX</c> + (did return true and an incorrect length value).</p> + <p> + Own Id: OTP-13288 Aux Id: PR913 </p> + </item> + <item> + <p> + Cleanup hipe signal handling code for x86 and make it + more portable.</p> + <p> + Own Id: OTP-13341 Aux Id: PR951 </p> + </item> + <item> + <p> + Make file:datasync use fsync instead of fdatasync on Mac + OSX.</p> + <p> + Own Id: OTP-13411</p> + </item> + <item> + <p> + Make sure to create a crash dump when running out of + memory. This was accidentally removed in the erts-7.3 + release.</p> + <p> + Own Id: OTP-13419</p> + </item> + <item> + <p> + A bug has been fixed where if erlang was started +B on a + unix platform it would be killed by a SIGUSR2 signal when + creating a crash dump.</p> + <p> + Own Id: OTP-13425</p> + </item> + <item> + <p> + Fix race between <c>process_flag(trap_exit,true)</c> and + a received exit signal.</p> + <p> + A process could terminate due to exit signal even though + <c>process_flag(trap_exit,true)</c> had returned. A very + specific timing between call to <c>process_flag/2</c> and + exit signal from another scheduler was required for this + to happen.</p> + <p> + Own Id: OTP-13452</p> + </item> + <item> + <p>Don't search for non-existing Map keys twice</p> + <p>For <c>maps:get/2,3</c> and <c>maps:find/2</c>, + searching for an immediate key, e.g. an atom, in a small + map, the search was performed twice if the key did not + exist.</p> + <p> + Own Id: OTP-13459</p> + </item> + <item> + <p> + When an abnormally large distribution message is about to + be sent, the VM has been changed to create a crash dump + instead of a core dump.</p> + <p> + Own Id: OTP-13474</p> + </item> + <item> + <p> + Fix <c>erlang:process_info/2</c> type specification</p> + <p> + Own Id: OTP-13485 Aux Id: ERL-123 </p> + </item> + <item> + <p> + Fix bug in <c>open_port/2</c> with option <c>{args, + List}</c>. A vm crash could be caused by an improper + <c>List</c>.</p> + <p> + Own Id: OTP-13489 Aux Id: ERL-127 </p> + </item> + <item> + <p> + Fixed a race-condition bug where the emulator could crash + when <c>erlang:system_profile/1,2</c> was enabled and a + process had to be re-scheduled during termination.</p> + <p> + Own Id: OTP-13494 Aux Id: ERL-126 </p> + </item> + <item> + <p> + Fixed bugs where the reduction counter was not handled + correct.</p> + <p> + Own Id: OTP-13512</p> + </item> + <item> + <p> + Fixed typo in description of the <c>EPMD_DUMP_REQ</c> + response.</p> + <p> + Own Id: OTP-13517</p> + </item> + <item> + <p> + Fixed a bug where a process flagged as sensitive would + sometimes record its save_calls when it shouldn't.</p> + <p> + Own Id: OTP-13540</p> + </item> + <item> + <p> + Update configure scripts to not use hard-coded path for + /bin/pwd and /bin/rm.</p> + <p> + Own Id: OTP-13562</p> + </item> + <item> + <p> + When passing a larger binary than the outputv callback of + a linked-in driver can handle in one io vector slot, the + binary is now split into multiple slots in the io vector. + This change only effects system where the max size of an + io vector slot is smaller then the word size of the + system (e.g. Windows).</p> + <p> + This change means that it is now possible on Windows to + send binaries that are larger than 4GB to port_command, + which is what is used for file:write, gen_tcp:send etc.</p> + <p> + Own Id: OTP-13628</p> + </item> + <item> + <p> + Workaround of Maps output in crashdumps. Currently the + atom 'undefined' is generated instead of Map data if a + Map type is encountered during crash.</p> + <p> + Own Id: OTP-13657</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + The tracing support has been extended to allow a <seealso + marker="erl_tracer">tracer module</seealso> to be the + trace event handler instead of a process or port. The + <seealso marker="erl_tracer">tracer module</seealso> + makes it possible for trace tools to filter or manipulate + trace event data without the trace event first having to + be copied from the traced process or port.</p> + <p> + With the introduction of this feature, + <c>erlang:trace(all|existing, _, _)</c> now also returns + the tracer process as part of the number of processes on + which tracing is enabled. The is incompatible with the + previous releases.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-10267</p> + </item> + <item> + <p> + Introduce LTTng tracing of Erlang Runtime System</p> + <p> + For LTTng to be enabled OTP needs to be built with + configure option <c>--with-dynamic-trace=lttng</c>.</p> + <p> + This feature introduces tracepoints for schedulers, + drivers, memory carriers, memory and async thread pool.</p> + <p> For a list of all tracepoints, see <seealso + marker="runtime_tools:LTTng">Runtime Tools User's + Guide</seealso> .</p> + <p> + Own Id: OTP-10282</p> + </item> + <item> + <p> + Make it possible to monitor/demonitor ports using the + <seealso + marker="erlang#monitor/2">erlang:monitor/2</seealso> API. + The process and port information functions have also been + updated to include information about monitors from + processes to ports.</p> + <p> + Own Id: OTP-11384</p> + </item> + <item> + <p> + Add microstate accounting</p> + <p> + Microstate accounting is a way to track which state the + different threads within ERTS are in. The main usage area + is to pin point performance bottlenecks by checking which + states the threads are in and then from there figuring + out why and where to optimize.</p> + <p> + Since checking whether microstate accounting is on or off + is relatively expensive only a few of the states are + enabled by default and more states can be enabled through + configure.</p> + <p> + There is a convenience module called msacc that has been + added to runtime_tools that can assist in gathering and + interpreting the data from Microstate accounting.</p> + <p> + For more information see <seealso + marker="erts:erlang#statistics_microstate_accounting">erlang:statistics(microstate_accounting, + _)</seealso> and the <seealso + marker="runtime_tools:msacc">msacc</seealso> module in + runtime_tools.</p> + <p> + Own Id: OTP-12345</p> + </item> + <item> + <p> + The port of Erlang/OTP to the real-time operating system + OSE has been removed.</p> + <p> + Own Id: OTP-12573</p> + </item> + <item> + <p> + Sharing preserved copy for messages and exit signals</p> + <p> + Enable sharing preserved copy with configure option + <c>--enable-sharing-preserving</c>. This will preserve + sharing, within the process, when communication with + other processes in the Erlang node. There is a trade-off, + the copy is more costly but this cost can be reclaimed if + there is a lot of sharing in the message. In addition + literals will not be copied in a send except during a + purge phase of the module where the literals are located. + This feature is considered experimental in 19.0.</p> + <p> + Own Id: OTP-12590 Aux Id: OTP-10251 </p> + </item> + <item> + <p> + Halfword BEAM has been removed.</p> + <p> + Own Id: OTP-12883</p> + </item> + <item> + <p> + Added <seealso + marker="kernel:os#perf_counter/1">os:perf_counter/1</seealso>.</p> + <p> + The perf_counter is a very very cheap and high resolution + timer that can be used to timestamp system events. It + does not have monoticity guarantees, but should on most + OS's expose a monotonous time.</p> + <p> + Own Id: OTP-12908</p> + </item> + <item> + <p> + Support for a fragmented young heap generation. That is, + the young heap generation can consist of multiple non + continuous memory areas. The main reason for this change + is to avoid extra copying of messages that could not be + allocated directly on the receivers heap.</p> + <p> + Own Id: OTP-13047</p> + </item> + <item> + <p> + Erlang linked-in driver can now force the call to + open_port to block until a call to erl_drv_init_ack is + made inside the driver. This is useful when you want to + do some asynchronous initialization, for example getting + configuration from a pipe, and you want the initial + open_port call to fail if the configuration is incomplete + or wrong. See the erl_driver documentation for more + details on the API.</p> + <p> + Own Id: OTP-13086</p> + </item> + <item> + <p> + Erlang linked-in drivers can now set their own pids as + seen in <c>erlang:port_info/1</c> by using the + <c>erl_drv_set_pid</c> function. For more details see the + erl_driver documentation.</p> + <p> + Own Id: OTP-13087</p> + </item> + <item> + <p> + The functionality behind <c>erlang:open_port/2</c> when + called with spawn or spawn_executable has been redone so + that the forking of the new program is done in a separate + process called erl_child_setup. This allows for a much + more robust implementation that uses less memory and does + not block the entire emulator if the program to be + started is on an un-accessible NFS. Benchmarks have shown + this approach to be about 3-5 times as fast as the old + approach where the fork/vfork was done by erts. This is a + pure stability and performance fix, however some error + messages may have changed, which is why it is marked as a + backwards incompatible change.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13088</p> + </item> + <item> + <p>Improved yielding strategy in the implementation of + the following native functions:</p> <list> + <item><c>erlang:binary_to_list/1</c></item> + <item><c>erlang:binary_to_list/3</c></item> + <item><c>erlang:bitstring_to_list/1</c></item> + <item><c>erlang:list_to_binary/1</c></item> + <item><c>erlang:iolist_to_binary/1</c></item> + <item><c>erlang:list_to_bitstring/1</c></item> + <item><c>binary:list_to_bin/1</c></item> </list> <p>This + in order to improve performance of these functions.</p> + <p> + Own Id: OTP-13096</p> + </item> + <item> + <p> + All garbage collections of processes now bump reductions. + Also the amount of reductions bumped when garbage + collecting has been adjusted. It now better corresponds + to the amount of work performed. This in order to improve + the real time characteristics of the system.</p> + <p> + Own Id: OTP-13097</p> + </item> + <item> + <p>New functions that can load multiple modules at once + have been added to the '<c>code</c>' module. The + functions are <c>code:atomic_load/1</c>, + <c>code:prepare_loading/1</c>, + <c>code:finish_loading/1</c>, and + <c>code:ensure_modules_loaded/1</c>.</p> + <p> + Own Id: OTP-13111</p> + </item> + <item> + <p>The <c>-boot_var</c> option for <c>erl</c> now only + supports a single key and single value (as documented). + The option used to allow multiple key/value pairs, but + that behavior was undocumented.</p> + <p>The function <c>erl_prim_loader:start/3</c> has been + removed. Its documentation has also been removed.</p> + <p>The undocumented and unsupported function + <c>erl_prim_loader:get_files/2</c> has been removed.</p> + <p> + Own Id: OTP-13112</p> + </item> + <item> + <p> + Low level BIF <c>erlang:purge_module/1</c> is made more + robust against incorrect use. Lingering processes that + still refer the old code are now killed before the module + is purged to prevent fatal VM behavior.</p> + <p> + Own Id: OTP-13122</p> + </item> + <item> + <p>Improved dirty scheduler implementation. For more + information see the <seealso + marker="erl_nif#dirty_nifs">NIF + documentation</seealso>.</p> <note><list> <item><p>The + dirty scheduler support is still + <em>experimental</em>.</p></item> <item><p>The support + for determining whether dirty NIF support exist or not at + compile time using the C preprocessor macro + <c>ERL_NIF_DIRTY_SCHEDULER_SUPPORT</c> has been + removed.</p></item> <item><p>The + <c>enif_is_on_dirty_scheduler()</c> function has been + removed. Use <seealso + marker="erl_nif#enif_thread_type"><c>enif_thread_type()</c></seealso> + instead.</p></item> </list></note> + <p> + Own Id: OTP-13123</p> + </item> + <item> + <p> + Various optimizations done to process dictionary access.</p> + <p> + Own Id: OTP-13167</p> + </item> + <item> + <p> + Added max_heap_size process flag. max_heap_size allows + the user to limit the maximum heap used by a process. See + <seealso + marker="erlang#process_flag/2">erlang:process_flag</seealso> + for more details.</p> + <p> + Own Id: OTP-13174</p> + </item> + <item> + <p> + Allow dynamic drivers and NIF libraries to be built with + gcc option <c>-fvisibility=hidden</c> for faster loading + and more optimized code.</p> + <p> + Own Id: OTP-13227</p> + </item> + <item> + <p> + Add <c>erlang:process_info(Pid, + garbage_collection_info)</c> which returns extended + garbage_collection information. For more details see the + documentation.</p> + <p> + Own Id: OTP-13265</p> + </item> + <item> + <p> + The functions <c>erlang:list_to_integer/1</c> and + <c>string:to_integer/1</c> have been optimized for large + inputs.</p> + <p> + Own Id: OTP-13293</p> + </item> + <item> + <p> + Improved memory allocation strategy for hipe native code + on x86_64 (amd64) architectures by reserving enough low + virtual address space needed for the HiPE/AMD64 small + code model. The default virtual address area for hipe + code is set to 512Mb, but can be changed with emulator + flag <c>+MXscs</c>.</p> + <p> + Own Id: OTP-13359</p> + </item> + <item> + <p> + Introduction of configurable management of data referred + to by the message queue of a process. Each process can be + configured individually.</p> + <p> + It is now possible to configure the message queue of a + process, so that all data referred by it will be kept + outside of the heap, and by this prevent this data from + being part of garbage collections.</p> + <p> + For more information see the documentation of <seealso + marker="erlang#process_flag_message_queue_data"><c>process_flag(message_queue_data, + MQD)</c></seealso>.</p> + <p> + Own Id: OTP-13366 Aux Id: OTP-13047 </p> + </item> + <item> + <p> + Processes now yield when scanning large message queues + and not finding a matching message. This in order to + improve real time characteristics.</p> + <p> + Own Id: OTP-13401</p> + </item> + <item> + <p> + Optimized an erts internal function that is used to + traverse erlang terms. The internal function was mainly + used by term_to_binary and comparison of terms. + Benchmarks have shown up to a 10% performance increase in + those functions after the optimization.</p> + <p> + Own Id: OTP-13440</p> + </item> + <item> + <p>Add the following NIF API functions:</p> + <list> <item><seealso + marker="erl_nif#enif_cpu_time"><c>enif_cpu_time</c></seealso></item> + <item><seealso + marker="erl_nif#enif_now_time"><c>enif_now_time</c></seealso></item> + <item><seealso + marker="erl_nif#enif_make_unique_integer"><c>enif_make_unique_integer</c></seealso></item> + <item><seealso + marker="erl_nif#enif_is_process_alive"><c>enif_is_process_alive</c></seealso></item> + <item><seealso + marker="erl_nif#enif_is_port_alive"><c>enif_is_port_alive</c></seealso></item> + <item><seealso + marker="erl_nif#enif_term_to_binary"><c>enif_term_to_binary</c></seealso></item> + <item><seealso + marker="erl_nif#enif_binary_to_term"><c>enif_binary_to_term</c></seealso></item> + <item><seealso + marker="erl_nif#enif_port_command"><c>enif_port_command</c></seealso></item> + </list> + <p> + For details of what each function does, see the erl_nif + documentation.</p> + <p> + Own Id: OTP-13442</p> + </item> + <item> + <p> + Optimize <c>'++'</c> operator and <c>lists:append/2</c> + by using a single pass to build a new list while checking + for properness.</p> + <p> + Own Id: OTP-13487</p> + </item> + <item> + <p> + Handle terms (pids,ports and refs) from nodes with a + 'creation' value larger than 3. This is a preparation of + the distribution protocol to allow OTP 19 nodes to + correctly communicate with future nodes (20 or higher). + The 'creation' value differentiates different + incarnations of the same node (name).</p> + <p> + Own Id: OTP-13488</p> + </item> + <item> + <p> + Don't send unasked for systemd notifications in epmd</p> + <p> + Own Id: OTP-13493 Aux Id: PR-999 </p> + </item> + <item> + <p> + The enif_send API has been extended to allow NULL to be + used as the message environment. When used this way, a + message environment is implicitly created and the given + term is copied into that environment before sending. This + can be an optimization if many small messages are being + sent by the nif.</p> + <p> + Own Id: OTP-13495</p> + </item> + <item> + <p> + The tracing support has been extended to allow tracing on + ports. Ports can be traced on using the 'ports', 'send' + and 'receive' trace flags.</p> + <p> + The first argument of <seealso + marker="erts:erlang#trace/3">erlang:trace/3</seealso> has + been extended so that <c>'all'</c>, <c>'existing'</c> and + <c>'new'</c> now include both processes and ports. New + <c>Tracee</c> variants, <c>'all_processes'</c>, + <c>'all_ports'</c>, <c>'existing_processes'</c> etc have + been added to specify only processes or ports.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13496</p> + </item> + <item> + <p> + When the <c>'procs'</c> trace flag is enabled, a + <c>'spawned'</c> trace event is now also generated by a + newly created process. The previous event <c>'spawn'</c> + remains, but as it is generated by the process that did + the spawn, it is not guaranteed that it is ordered with + other trace events from the newly spawned process. So + when tracking the lifetime of a process this new event + should be used as the creation event.</p> + <p> + This new trace event is marked as an incompatibility + because tools that expect certain trace events when + enabling 'procs' will have to updated.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13497</p> + </item> + <item> + <p> + Add the <seealso + marker="erts:erlang#match_spec_test/3">erlang:match_spec_test/3</seealso> + function. The functions allows the testing of match + specifications for both tracing and ets tables. It can be + used to test that a match specification does the expected + filtering on specific data. It also returns more verbose + error reasons for incorrectly constructed match + specifications.</p> + <p> + Own Id: OTP-13501</p> + </item> + <item> + <p> + The erts internal tracing support has been changed to + have much less overhead and be more scalable.</p> + <p> + This rewrite does not break any backwards + incompatibilities, but it does change the ordering of + some trace messages when compared to previous releases. + It should be noted that this only applies to trace + messages sent to processes or ports, it does not apply to + the new tracer module. However in future releases they + may also be effected by this.</p> + <p> + Trace messages are only guaranteed to be ordered from one + traced process or port. In previous releases this was not + visible as a <c>'send'</c> trace message would always + arrive before the corresponding <c>'receive'</c> trace + message that is no longer always the case. This also + means that timestamped trace messages may seem to arrive + out of order as the timestamp is taken when the event is + triggered and not when it is put in the queue of the + tracer.</p> + <p> + Own Id: OTP-13503</p> + </item> + <item> + <p> + Add possibility to filter <c>send</c> and <c>receive</c> + trace with match specifications.</p> + <p> + Own Id: OTP-13507</p> + </item> + <item> + <p> + Add <c>maps:update_with/3,4</c> and <c>maps:take/2</c></p> + <p> + Own Id: OTP-13522 Aux Id: PR-1025 </p> + </item> + <item> + <p> + Introduce LTTng tracing via Erlang tracing.</p> + <p> + For LTTng to be enabled OTP needs to be built with + configure option <c>--with-dynamic-trace=lttng</c>.</p> + <p>The dynamic trace module <c>dyntrace</c> is now + capable to be used as a LTTng sink for Erlang tracing. + For a list of all tracepoints, see <seealso + marker="runtime_tools:LTTng">Runtime Tools User's + Guide</seealso> .</p> + <p>This feature also introduces an incompatible change in + trace tags. The trace tags <c>gc_start</c> and + <c>gc_end</c> has been split into <c>gc_minor_start</c>, + <c>gc_minor_end</c> and <c>gc_major_start</c>, + <c>gc_major_end</c>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13532</p> + </item> + <item> + <p> + Print heap pointers for garbing processes during + crashdump</p> + <p> + Own Id: OTP-13541 Aux Id: PR-1026 </p> + </item> + <item> + <p> + Changed and improved low level memory statistics returned + by <c>erlang:system_info/1</c>. The info for + <c>erts_mmap</c> has been moved from <c>mseg_alloc</c> to + its own section returned by <c>{allocator, + erts_mmap}</c>.</p> + <p> + Own Id: OTP-13560</p> + </item> + <item> + <p> + Add enif_snprintf to the NIF API</p> + <p> + The function <c>enif_snprintf</c> is similar to + <c>snprintf</c> call but can handle formatting of Erlang + terms via <c>%T</c> format specifier.</p> + <p> + Own Id: OTP-13580</p> + </item> + <item> + <p>The warning in the documentation for + <c>erlang:raise/3</c> has been removed. It is now + officially perfectly fine to use raise/3 in production + code.</p> + <p> + Own Id: OTP-13599</p> + </item> + <item> + <p> + Fix bugs caused by the VM sometimes truncating object + sizes or offsets to 32 bits on 64-bit hosts. These bugs + were mainly found when working with large unicode strings + and nifs environments.</p> + <p> + Own Id: OTP-13606</p> + </item> + <item> + <p> + Add <c>-start_epmd</c> command line option, this lets you + disable automatic starting of epmd when starting a + distributed node.</p> + <p> + Add <c>-epmd_module</c> command line option, this lets + you specify a module to register and look-up node names + in. The default module is <c>erl_epmd</c>.</p> + <p> + Own Id: OTP-13627</p> + </item> + <item> + <p> + <c>erlang:halt</c> now truncates strings longer than 200 + characters instead of failing with <c>badarg</c>.</p> + <p> + Own Id: OTP-13630</p> + </item> + <item> + <p> + Fix possible race in poller wake up on windows</p> + <p> + Own Id: OTP-13634</p> + </item> + </list> + </section> + +</section> + <section><title>Erts 7.3.1.5</title> <section><title>Fixed Bugs and Malfunctions</title> @@ -48,7 +4792,6 @@ </section> <section><title>Erts 7.3.1.4</title> - <section><title>Fixed Bugs and Malfunctions</title> <list> <item> @@ -98,7 +4841,6 @@ </item> </list> </section> - </section> <section><title>Erts 7.3.1.3</title> @@ -1140,8 +5882,7 @@ <p>The previously introduced "eager check I/O" feature is now enabled by default.</p> <p>Eager check I/O can be disabled using the <c>erl</c> - command line argument: <seealso - marker="erl#+secio"><c>+secio false</c></seealso></p> + command line argument: <c>+secio false</c></p> <p>Characteristics impact compared to previous default:</p> <list> <item>Lower latency and smoother management of externally triggered I/O operations.</item> @@ -1542,6 +6283,103 @@ </section> +<section><title>Erts 6.4.1.7</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A process communicating with a port via one of the + <c>erlang:port_*</c> BIFs could potentially end up in an + inconsistent state if the port terminated during the + communication. When this occurred the process could later + block in a <c>receive</c> even though it had messages + matching in its message queue.</p> + <p> + This bug was introduced in erts version 5.10 (OTP R16A).</p> + <p> + Own Id: OTP-13424 Aux Id: OTP-10336 </p> + </item> + <item> + <p> + Calls to <c>erl_drv_send_term()</c> or + <c>erl_drv_output_term()</c> from a non-scheduler thread + while the corresponding port was invalid caused the + emulator to enter an inconsistent state which eventually + caused an emulator crash.</p> + <p> + Own Id: OTP-13866</p> + </item> + <item> + <p>Driver and NIF operations accessing processes or ports + could cause an emulator crash when used from + non-scheduler threads. Those operations are:</p> <list> + <item><c>erl_drv_send_term()</c></item> + <item><c>driver_send_term()</c></item> + <item><c>erl_drv_output_term()</c></item> + <item><c>driver_output_term()</c></item> + <item><c>enif_send()</c></item> + <item><c>enif_port_command()</c></item> </list> + <p> + Own Id: OTP-13869</p> + </item> + <item> + <p> + Fix bug in <c>binary_to_term</c> for binaries created by + <c>term_to_binary </c> with option <c>compressed</c>. The + bug can cause <c>badarg</c> exception for a valid binary + when Erlang VM is linked against a <c>zlib</c> library of + version 1.2.9 or newer. Bug exists since OTP 17.0.</p> + <p> + Own Id: OTP-14159 Aux Id: ERL-340 </p> + </item> + <item> + <p> + Fixed bug in operator <c>bxor</c> causing erroneuos + result when one operand is a big <em>negative</em> + integer with the lowest <c>N*W</c> bits as zero and the + other operand not larger than <c>N*W</c> bits. <c>N</c> + is an integer of 1 or larger and <c>W</c> is 32 or 64 + depending on word size.</p> + <p> + Own Id: OTP-14514</p> + </item> + <item> + <p> + Fixed bug in <c>binary_to_term</c> and + <c>binary_to_atom</c> that could cause VM crash. + Typically happens when the last character of an UTF8 + string is in the range 128 to 255, but truncated to only + one byte. Bug exists in <c>binary_to_term</c> since ERTS + version 5.10.2 (OTP_R16B01) and <c>binary_to_atom</c> + since ERTS version 9.0 (OTP-20.0).</p> + <p> + Own Id: OTP-14590 Aux Id: ERL-474 </p> + </item> + </list> + </section> + +</section> + +<section><title>Erts 6.4.1.6</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + When calling <c>garbage_collect/[1,2]</c> or + <c>check_process_code/[2,3]</c> from a process with a + higher priority than the priority of the process operated + on, the run queues could end up in an inconsistent state. + This bug has now been fixed.</p> + <p> + Own Id: OTP-13298 Aux Id: OTP-11388 </p> + </item> + </list> + </section> + +</section> + <section><title>Erts 6.4.1.5</title> <section><title>Fixed Bugs and Malfunctions</title> @@ -1922,8 +6760,7 @@ prioritized to the same extent as when eager check I/O is disabled.</p> <p>Eager check I/O can be enabled using the <c>erl</c> - command line argument: <seealso - marker="erl#+secio"><c>+secio true</c></seealso></p> + command line argument: <c>+secio true</c></p> <p>Characteristics impact when enabled:</p> <list> <item>Lower latency and smoother management of externally triggered I/O operations.</item> <item>A slightly reduced @@ -4506,7 +9343,7 @@ dependent, so applications aiming to be portable should consider using <c>{ipv6_v6only,true}</c> when creating an <c>inet6</c> listening/destination socket, and if - neccesary also create an <c>inet</c> socket on the same + necessary also create an <c>inet</c> socket on the same port for IPv4 traffic. See the documentation.</p> <p> Own Id: OTP-8928 Aux Id: kunagi-193 [104] </p> @@ -4887,7 +9724,7 @@ This change of default value will reduce lock contention on ETS tables using the <c>read_concurrency</c> option at the expense of memory consumption when the amount of - schedulers and logical processors are beween 8 and 64. + schedulers and logical processors are between 8 and 64. For more information, see documentation of the <c>+rg</c> command line argument of <c>erl(1)</c>.</p> <p> @@ -5864,7 +10701,7 @@ <p> For the subsection about process_flag(save_calls, N) there's an unrelated paragraph about process priorities - which was copied from the preceeding subsection regarding + which was copied from the preceding subsection regarding process_flag(priority, Level). (Thanks to Filipe David Manana)</p> <p> @@ -7079,7 +11916,7 @@ <item> <p> Wx on MacOS X generated complains on stderr about certain - cocoa functions not beeing called from the "Main thread". + cocoa functions not being called from the "Main thread". This is now corrected.</p> <p> Own Id: OTP-9081</p> @@ -7917,7 +12754,7 @@ <c>update_cpu_info</c> will make the runtime system reread and update the internally stored CPU information. For more information see the documentation of <seealso - marker="erlang#update_cpu_info">erlang:system_info(update_cpu_info)</seealso>.</p> + marker="erlang#system_info_update_cpu_info">erlang:system_info(update_cpu_info)</seealso>.</p> <p> The CPU topology is now automatically detected on Windows systems with less than 33 logical processors. The runtime @@ -8070,7 +12907,7 @@ </item> <item> <p>The <c>empd</c> program could loop and consume 100% - CPU time if an unexpected error ocurred in + CPU time if an unexpected error occurred in <c>listen()</c> or <c>accept()</c>. Now <c>epmd</c> will terminate if a non-recoverable error occurs. (Thanks to Michael Santos.)</p> @@ -8764,9 +13601,9 @@ dynamically linking against <c>libssl.so</c> and <c>libcrypto.so</c>. The runtime library search path has also been extended. </item><item> The <c>configure</c> - scripts of <c>erl_interface</c> and <c>odbc</c> now + scripts of Erl_interface and ODBC now search for thread libraries and thread library quirks the - same way as <c>erts</c> do. </item><item> The + same way as ERTS do. </item><item> The <c>configure</c> script of the <c>odbc</c> application now also looks for odbc libraries in <c>lib64</c> and <c>lib/64</c> directories when building on a 64-bit @@ -9882,7 +14719,7 @@ </item> <item> <p> - A corrected bug in <c>ets</c> for <c>bag</c> and + A corrected bug in ETS for <c>bag</c> and <c>duplicate_bag</c>. A <c>delete/2</c> or <c>lookup_element/3</c> could miss objects in a fixed table if one or more objects with the same key had @@ -10324,7 +15161,7 @@ <list> <item> <p> - A corrected bug in <c>ets</c> for <c>bag</c> and + A corrected bug in ETS for <c>bag</c> and <c>duplicate_bag</c>. A <c>delete/2</c> or <c>lookup_element/3</c> could miss objects in a fixed table if one or more objects with the same key had @@ -14369,4 +19206,3 @@ </section> </section> </chapter> - |