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diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml index 4cef9669dd..cfee978bde 100644 --- a/erts/doc/src/notes.xml +++ b/erts/doc/src/notes.xml @@ -30,6 +30,478 @@ </header> <p>This document describes the changes made to the ERTS application.</p> +<section><title>Erts 5.9</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Honor option <c>packet_size</c> for http packet parsing + by both TCP socket and <c>erlang:decode_packet</c>. This + gives the ability to accept HTTP headers larger than the + default setting, but also avoid DoS attacks by accepting + lines only up to whatever length you wish to allow. For + consistency, packet type <c>line</c> also honor option + <c>packet_size</c>. (Thanks to Steve Vinoski)</p> + <p> + Own Id: OTP-9389</p> + </item> + <item> + <p> A few contracts in the <c>lists</c> module have been + corrected. </p> + <p> + Own Id: OTP-9616</p> + </item> + <item> + <p> + The Unicode noncharacter code points 16#FFFE and 16#FFFE + were not allowed to be encoded or decoded using the + <c>unicode</c> module or bit syntax. That was + inconsistent with the other noncharacters 16#FDD0 to + 16#FDEF that could be encoded/decoded. To resolve the + inconsistency, 16#FFFE and 16#FFFE can now be encoded and + decoded. (Thanks to Alisdair Sullivan.)</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9624</p> + </item> + <item> + <p> + Make epp search directory of current file first when + including another file This completes a partial fix in + R11 that only worked for include_lib(). (Thanks to + Richard Carlsson)</p> + <p> + Own Id: OTP-9645</p> + </item> + <item> + <p> + Fixed memory leak in + <c>enif_inspect_io_list_as_binary</c> when applied on a + process independent environment.</p> + <p> + Own Id: OTP-9668</p> + </item> + <item> + <p>The number of beam catches allowed in code are no + longer statically defined and will grow according to its + need.</p> + <p> + Own Id: OTP-9692</p> + </item> + <item> + <p> + Add missing parenthesis in heart doc.</p> + <p> + Add missing spaces in the Reference Manual distributed + section.</p> + <p> + In the HTML version of the doc those spaces are necessary + to separate those words.</p> + <p> + Own Id: OTP-9693</p> + </item> + <item> + <p> + Fixes module erlang doc style: option description (Thanks + to Ricardo Catalinas Jim�nez)</p> + <p> + Own Id: OTP-9697</p> + </item> + <item> + <p> + Specifying a scope to binary:match/3 when using multiple + searchstrings resulted in faulty return values. This is + now corrected.</p> + <p> + Own Id: OTP-9701</p> + </item> + <item> + <p> + The runtime system crashed if more than one thread tried + to exit the runtime system at the same time.</p> + <p> + Own Id: OTP-9705</p> + </item> + <item> + <p> + Fix documentation for erlang:process_flag/2</p> + <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 + process_flag(priority, Level). (Thanks to Filipe David + Manana)</p> + <p> + Own Id: OTP-9714</p> + </item> + <item> + <p> + Calls to <c>erlang:system_flag(schedulers_online, N)</c> + and/or <c>erlang:system_flag(multi_scheduling, + block|unblock)</c> could cause internal data used by this + functionality to get into an inconsistent state. When + this happened various problems occurred. This bug was + quite hard to trigger, so hopefully no-one has been + effected by it.</p> + <p> + A spinlock used by the run-queue management sometimes got + heavily contended. This code has now been rewritten, and + the spinlock has been removed.</p> + <p> + Own Id: OTP-9727</p> + </item> + <item> + <p> + Use libdlpi to get physical address (Thanks to Trond + Norbye)</p> + <p> + Own Id: OTP-9818</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> An option list argument can now be passed to + <c>file:read_file_info/2, file:read_link_info/2</c> and + <c>file:write_file_info/3</c> and set time type + information in the call. Valid options are <c>{time, + local}, {time, universal}</c> and <c>{time, posix}</c>. + In the case of <c>posix</c> time no conversions are made + which makes the operation a bit faster. </p> + <p> + Own Id: OTP-7687</p> + </item> + <item> + <p>A number of memory allocation optimizations have been + implemented. Most optimizations reduce contention caused + by synchronization between threads during allocation and + deallocation of memory. Most notably:</p> <list> <item> + Synchronization of memory management in scheduler + specific allocator instances has been rewritten to use + lock-free synchronization. </item> <item> Synchronization + of memory management in scheduler specific pre-allocators + has been rewritten to use lock-free synchronization. + </item> <item> The 'mseg_alloc' memory segment allocator + now use scheduler specific instances instead of one + instance. Apart from reducing contention this also + ensures that memory allocators always create memory + segments on the local NUMA node on a NUMA system. </item> + </list> + <p> + Own Id: OTP-7775</p> + </item> + <item> + <p> + The ethread atomic memory operations API used by the + runtime system has been extended and improved.</p> + <p> + The ethread library now also performs runtime tests for + presence of hardware features, such as for example SSE2 + instructions, instead of requiring this to be determined + at compile time.</p> + <p> + All uses of the old deprecated atomic API in the runtime + system have been replaced with the use of the new atomic + API. In a lot of places this change imply a relaxation of + memory barriers used.</p> + <p> + Own Id: OTP-9014</p> + </item> + <item> + <p>gen_sctp:open/0-2 may now return + {error,eprotonosupport} if SCTP is not supported</p> + <p>gen_sctp:peeloff/1 has been implemented and creates a + one-to-one socket which also are supported now</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9239</p> + </item> + <item> + <p> + Sendfile has been added to the file module's API. + sendfile/2 is used to read data from a file and send it + to a tcp socket using a zero copying mechanism if + available on that OS.</p> + <p> + Thanks to Tuncer Ayaz and Steve Vinovski for original + implementation</p> + <p> + Own Id: OTP-9240</p> + </item> + <item> + <p> + enif_get_reverse_list function added to nif API. This + function should be used to reverse small lists which are + deep within other structures making it impractical to do + the reverse in Erlang.</p> + <p> + Own Id: OTP-9392</p> + </item> + <item> + <p> + The deprecated concat_binary/1 BIF has been removed. Use + <c>list_to_binary</c> or <c>iolist_to_binary/1</c> + instead.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9421</p> + </item> + <item> + <p>Erlang/OTP can now be built using parallel make if you + limit the number of jobs, for instance using '<c>make + -j6</c>' or '<c>make -j10</c>'. '<c>make -j</c>' does not + work at the moment because of some missing + dependencies.</p> + <p> + Own Id: OTP-9451</p> + </item> + <item> + <p>Line number and filename information are now included + in exception backtraces as a fourth element in the MFA + tuple. The information will be pretty-printed by the + shell and used by <c>common_test</c> to provide better + indication of where a test case.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9468</p> + </item> + <item> + <p>All binary constants used to be handled as heap + binaries (i.e. the entire binary would be copied when + sent to another process). Binary constants larger than 64 + bytes are now refc binaries (i.e. the actual data in the + binary will not be copied when sent to another + process).</p> + <p> + Own Id: OTP-9486</p> + </item> + <item> + <p> + If a float and an integer is compared, the integer is + only converted to a float if the float datatype can + contain it. Otherwise the float is converted to an + integer.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9497</p> + </item> + <item> + <p> + Add NIF function enif_is_number</p> + <p> + This function allows for easily determining if a term + represents or not a number (integer, float, small or + big).(Thanks to Filipe David Manana)</p> + <p> + Own Id: OTP-9629</p> + </item> + <item> + <p> + The ERTS internal system block functionality has been + replaced by new functionality for blocking the system. + The old system block functionality had contention issues + and complexity issues. The new functionality piggy-backs + on thread progress tracking functionality needed by newly + introduced lock-free synchronization in the runtime + system. When the functionality for blocking the system + isn't used, there is more or less no overhead at all. + This since the functionality for tracking thread progress + is there and needed anyway.</p> + <p> + Own Id: OTP-9631</p> + </item> + <item> + <p> + An ERTS internal, generic, many to one, lock-free queue + for communication between threads has been introduced. + The many to one scenario is very common in ERTS, so it + can be used in a lot of places in the future. Currently + it is used by scheduling of certain jobs, and the async + thread pool, but more uses are planned for the future.</p> + <p> + Drivers using the driver_async functionality are not + automatically locked to the system anymore, and can be + unloaded as any dynamically linked in driver.</p> + <p> + Scheduling of ready async jobs is now also interleaved in + between other jobs. Previously all ready async jobs were + performed at once.</p> + <p> + Own Id: OTP-9632</p> + </item> + <item> + <p> + Tuple funs (a two-element tuple with a module name and a + function) are now officially deprecated and will be + removed in R16. Use '<c>fun M:F/A</c>' instead. To make + you aware that your system uses tuple funs, the very + first time a tuple fun is applied, a warning will be sent + to the error logger.</p> + <p> + Own Id: OTP-9649</p> + </item> + <item> + <p> + Changed the internal BIF calling convention. Will make + simpler faster code and allow BIFs with an arbitrary + arity.</p> + <p> + Own Id: OTP-9662</p> + </item> + <item> + <p> + Windows native critical sections are now used internally + in the runtime system on Windows as mutex implementation. + This since they perform better under extreme contention + than our own implementation.</p> + <p> + Own Id: OTP-9671</p> + </item> + <item> + <p> + Convert some erl_nif macros into inline functions. Allow + for better compile time type checking. (Thanks to Tuncer + Ayaz)</p> + <p> + Own Id: OTP-9675</p> + </item> + <item> + <p> + The <c>+scl</c> command line flag has been added. It can + be used for disabling compaction of scheduler load. For + more information see the <c>erl(1)</c> documentation.</p> + <p> + Own Id: OTP-9695</p> + </item> + <item> + <p>The build system has been updated so that Erlang/OTP + can be built on Mac OS X Lion systems without a GCC + compiler. The INSTALL guide has been updated with + instructions on how to install a GCC compiler and build + Erlang/OTP with it, in order to get a run-time system + with better performance.</p> + <p> + Own Id: OTP-9712</p> + </item> + <item> + <p> + When loading a module, the system use to run on a single + scheduler during the entire loading process. This has + been changed to only take down the system just before + inserting the loaded code into the system tables, + resulting in a much shorter disruption if a module is + loaded in a busy system. (Suggested by Bob Ippolito.)</p> + <p> + Own Id: OTP-9720</p> + </item> + <item> + <p> + Possible to run HiPE without floating point exceptions + (FPE). Useful on platforms that lack reliable FPE. Slower + float operations compared to HiPE with FPE.</p> + <p> + Own Id: OTP-9724</p> + </item> + <item> + <p> + As of ERTS version 5.9 (OTP-R15B) the runtime system will + by default <em>not</em> bind schedulers to logical + processors.</p> + <p> + If the Erlang runtime system is the only operating system + process that binds threads to logical processors, this + improves the performance of the runtime system. However, + if other operating system processes (as for example + another Erlang runtime system) also bind threads to + logical processors, there might be a performance penalty + instead. In some cases this performance penalty might be + severe. Due to this, we change the default so that the + user must make an active decision in order to bind + schedulers.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9726</p> + </item> + <item> + <p> + The use of <c>erlang:system_flag(scheduler_bind_type, + _)</c> and <c>erlang:system_flag(cpu_topology, _)</c> + have been deprecated and scheduled for removal in + erts-5.10/OTP-R16. For more information see the + documentation of <c>erlang:system_flag/2</c>.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9749</p> + </item> + <item> + <p> + An ancient workaround for a Windows bug was removed from + the open_port code, open_port({spawn,...}...) is now + faster. Thanks to Daniel Goertzen.</p> + <p> + Own Id: OTP-9766</p> + </item> + <item> + <p> + The use of deprecated 32bit time_t on 32bit Windows is + removed.</p> + <p> + Own Id: OTP-9767</p> + </item> + <item> + <p> + The NIF <c>reload</c> mechanism is deprecated. Do not use + it as an upgrade method for live production systems. It + might be removed in future releases. It can still serve + as a development feature but a warning message will be + logged each time it is used.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9771</p> + </item> + <item> + <p>The driver interface has been changed to enable 64-bit + aware drivers. Most importantly the return types for + ErlDrvEntry callbacks 'call' and 'control' has ben + enlarged which require drivers to be changed or they will + cause emulator crashes. See <seealso + marker="erl_driver#rewrites_for_64_bits"> Rewrites for + 64-bit driver interface </seealso> in the driver manual. + </p> + <p>Due to this driver <seealso + marker="erl_driver#version_management">version + management</seealso> is now mandatory. A driver that is + not written with version management or a driver that was + compiled with the wrong major version will be not be + loaded by the emulator.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-9795</p> + </item> + <item> + <p> + Eliminate use of deprecated regexp module</p> + <p> + Own Id: OTP-9810</p> + </item> + </list> + </section> + +</section> + <section><title>Erts 5.8.5</title> <section><title>Fixed Bugs and Malfunctions</title> |