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2018-09-24Support using match contexts from Y registersJohn Högberg
The upcoming beam_ssa_bsm pass allows match contexts to be used across function calls that take said context as an argument, which means it's fairly common for them to end up in Y registers.
2018-09-21Merge branch 'sverker/erts/beautify-ifdef-DEBUG'Sverker Eriksson
* sverker/erts/beautify-ifdef-DEBUG: erts: Beautify away #ifdef DEBUG
2018-09-21Merge PR-1952 from kjellwinblad/ca_tree_pull_requestSverker Eriksson
Add a more scalable ETS ordered_set implementation
2018-09-21Merge branch 'maint'Henrik Nord
2018-09-21Update copyright yearHenrik Nord
2018-09-19Merge branch 'maint'Raimo Niskanen
2018-09-19Merge branch 'raimo/receive-TOS-TCLASS/ERIERL-187/OTP-15145' into maintRaimo Niskanen
* raimo/receive-TOS-TCLASS/ERIERL-187/OTP-15145: Elaborate the disclaimer for 'pktoptions' Improve platform filter Fix endianness bug for CMSG parsing
2018-09-19Fix endianness bug for CMSG parsingRaimo Niskanen
2018-09-18Merge branch 'maint'Sverker Eriksson
2018-09-18Merge branch 'sverker/erts/robustify-dist-entry-states/OTP-15297' into maintSverker Eriksson
* sverker/erts/robustify-dist-entry-states/OTP-15297: erts: Refactor port dist_entry & conn_id into PRTSD Remove ugly fail case macros Consolidate distribution entry state transitions erts: Fix bug in undocumented system_flag(scheduling_statistics)
2018-09-18Merge 'sverker/erts/fix-aborted-pending-connection-race/OTP-15296'Sverker Eriksson
2018-09-18erts: Refactor port dist_entry & conn_id into PRTSDSverker Eriksson
spelled out as "port specific data".
2018-09-18Remove ugly fail case macrosSverker Eriksson
2018-09-18Consolidate distribution entry state transitionsSverker Eriksson
* Make connection_id part of the distribution handle as {ConnId, DistEntry} in order for BIFs to verify correct connection. * Make distribution handle opaque to net_kernel. * Remove some unsafe lockless reads of DistEntry.flags * Change state ERTS_DE_STATE_EXITING to be more of an internal state that prevents erts from enqueue, encode or schedule new data to be sent. Otherwise it should behave like ERTS_DE_STATE_CONNECTED.
2018-09-17Merge branch 'maint'Raimo Niskanen
2018-09-17Merge branch 'raimo/receive-TOS-TCLASS/ERIERL-187/OTP-15145' into maintRaimo Niskanen
* raimo/receive-TOS-TCLASS/ERIERL-187/OTP-15145: Write testcases for recvtos and friends Fix term buffer overflow bug Fix documentation due to feedback Implement socket option recvtos and friends
2018-09-17Merge branch 'maint'John Högberg
* maint: Improve trapping in lists:reverse/2 Fix unsafe use of lists:reverse/1
2018-09-17Merge branch 'john/erts/improve-list-reverse-trapping/OTP-15199' into maintJohn Högberg
* john/erts/improve-list-reverse-trapping/OTP-15199: Improve trapping in lists:reverse/2 Fix unsafe use of lists:reverse/1
2018-09-13Improve trapping in lists:reverse/2John Högberg
If the process had more free space than reductions it could run a lot longer than it was supposed to. It didn't honor the number of reductions going in either, nor did it bump reductions when returning its result or erroring out. This commit also removes this function from a work function in scheduler_SUITE as it's extremely sensitive to the number of reductions spent in the test, causing equal_and_high_with_part_time_max to fail on some machines.
2018-09-12Merge branch 'maint'Rickard Green
* maint: Updated OTP version Update release notes Update version numbers erts: Fix "Prevent inconsistent node lists" fix Fix include-path regression caused by dd0a39c Restore default SIGTERM behaviour for port programs
2018-09-12Merge branch 'maint-21' into maintRickard Green
* maint-21: Updated OTP version Update release notes Update version numbers erts: Fix "Prevent inconsistent node lists" fix Fix include-path regression caused by dd0a39c Restore default SIGTERM behaviour for port programs
2018-09-11Merge branch 'sverker/enif-cancel-select/OTP-15095'Sverker Eriksson
* sverker/enif-cancel-select/OTP-15095: erts: Add ERL_NIF_SELECT_CANCEL flag for enif_select
2018-09-11erts: Fix bug in undocumented system_flag(scheduling_statistics)Sverker Eriksson
Uses port specific data out of bounds.
2018-09-11Merge branch 'sverker/erts/fix-aborted-pending-connection-race/OTP-15296' ↵Erlang/OTP
into maint-21 * sverker/erts/fix-aborted-pending-connection-race/OTP-15296: erts: Fix "Prevent inconsistent node lists" fix
2018-09-11erts: Fix "Prevent inconsistent node lists" fixSverker Eriksson
done in a31216200bdee2c04b3fb3ae5e26607674715c8a that could cause a new pending connection to be incorrectly aborted.
2018-09-11Fix term buffer overflow bugRaimo Niskanen
2018-09-10Restore default SIGTERM behaviour for port programsRickard Green
erl_child_setup program ignores TERM signals as of ERTS version 10.0 (cff8dce0). This setting was unfortunately inherited by port programs. This commit restores handling of TERM signals in port programs to the default behavior. That is, terminate the process.
2018-09-07erts: Beautify away #ifdef DEBUGSverker Eriksson
"(void)result" will silence warning about unused variable and compiler will optimize away such unused variables.
2018-09-06Merge branch 'maint'Rickard Green
* maint: Update PCRE from version 8.41 to version 8.42
2018-09-06Merge branch 'rickard/pcre-8.42/OTP-15217' into maintRickard Green
* rickard/pcre-8.42/OTP-15217: Update PCRE from version 8.41 to version 8.42
2018-09-06Merge branch 'maint'Rickard Green
* maint: Updated OTP version Update release notes Update version numbers kernel: Fix missing abort_connection in net_kernel Prevent inconsistent node lists Fix an endless rescheduling loop when a process is executing process_info(self(), ...)
2018-09-06Merge branch 'maint-21' into maintRickard Green
* maint-21: Updated OTP version Update release notes Update version numbers kernel: Fix missing abort_connection in net_kernel Prevent inconsistent node lists Fix an endless rescheduling loop when a process is executing process_info(self(), ...)
2018-09-06Merge branch 'maint'Rickard Green
* maint: Fix an endless rescheduling loop when a process is executing process_info(self(), ...)
2018-09-06Merge pull request #1943 from max-au/handle_signals_before_dirty_gcRickard Green
Fix an endless rescheduling loop when a process is executing process_… OTP-15275
2018-09-05Add a more scalable ETS ordered_set implementationKjell Winblad
The current ETS ordered_set implementation can quickly become a scalability bottleneck on multicore machines when an application updates an ordered_set table from concurrent processes [1][2]. The current implementation is based on an AVL tree protected from concurrent writes by a single readers-writer lock. Furthermore, the current implementation has an optimization, called the stack optimization [3], that can improve the performance when only a single process accesses a table but can cause bad scalability even in read-only scenarios. It is possible to pass the option {write_concurrency, true} to ets:new/2 when creating an ETS table of type ordered_set but this option has no effect for tables of type ordered_set without this commit. The new ETS ordered_set implementation, added by this commit, is only activated when one passes the options ordered_set and {write_concurrency, true} to the ets:new/2 function. Thus, the previous ordered_set implementation (from here on called the default implementation) can still be used in applications that do not benefit from the new implementation. The benchmark results on the following web page show that the new implementation is many times faster than the old implementation in some scenarios and that the old implementation is still better than the new implementation in some scenarios. http://winsh.me/ets_catree_benchmark/ets_ca_tree_benchmark_results.html The new implementation is expected to scale better than the default implementation when concurrent processes use the following ETS operations to operate on a table: delete/2, delete_object/2, first/1, insert/2 (single object), insert_new/2 (single object), lookup/2, lookup_element/2, member/2, next/2, take/2 and update_element/3 (single object). Currently, the new implementation does not have scalable support for the other operations (e.g., select/2). However, when these operations are used infrequently, the new implantation may still scale better than the default implementation as the benchmark results at the URL above shows. Description of the New Implementation ---------------------------------- The new implementation is based on a data structure which is called the contention adapting search tree (CA tree for short). The following publication contains a detailed description of the CA tree: A Contention Adapting Approach to Concurrent Ordered Sets Journal of Parallel and Distributed Computing, 2018 Kjell Winblad and Konstantinos Sagonas https://doi.org/10.1016/j.jpdc.2017.11.007 http://www.it.uu.se/research/group/languages/software/ca_tree/catree_proofs.pdf A discussion of how the CA tree can be used as an ETS back-end can be found in another publication [1]. The CA tree is a data structure that dynamically changes its synchronization granularity based on detected contention. Internally, the CA tree uses instances of a sequential data structure to store items. The CA tree implementation contained in this commit uses the same AVL tree implementation as is used for the default ordered set implementation. This AVL tree implementation is reused so that much of the existing code to implement the ETS operations can be reused. Tests ----- The ETS tests in `lib/stdlib/test/ets_SUITE.erl` have been extended to also test the new ordered_set implementation. The function ets_SUITE:throughput_benchmark/0 has also been added to this file. This function can be used to measure and compare the performance of the different ETS table types and options. This function writes benchmark data to standard output that can be visualized by the HTML page `lib/stdlib/test/ets_SUITE_data/visualize_throughput.html`. [1] More Scalable Ordered Set for ETS Using Adaptation. In Thirteenth ACM SIGPLAN workshop on Erlang (2014). Kjell Winblad and Konstantinos Sagonas. https://doi.org/10.1145/2633448.2633455 http://www.it.uu.se/research/group/languages/software/ca_tree/erlang_paper.pdf [2] On the Scalability of the Erlang Term Storage In Twelfth ACM SIGPLAN workshop on Erlang (2013) Kjell Winblad, David Klaftenegger and Konstantinos Sagonas https://doi.org/10.1145/2505305.2505308 http://winsh.me/papers/erlang_workshop_2013.pdf [3] The stack optimization works by keeping one preallocated stack instance in every ordered_set table. This stack is updated so that it contains the search path in some read operations (e.g., ets:next/2). This makes it possible for a subsequent ets:next/2 to avoid traversing some nodes in some cases. Unfortunately, the preallocated stack needs to be flagged so that it is not updated concurrently by several threads which cause bad scalability.
2018-09-05Merge branch 'rickard/dist-entry-gc-fix/OTP-15279' into maint-21Erlang/OTP
* rickard/dist-entry-gc-fix/OTP-15279: Prevent inconsistent node lists
2018-09-05Prevent inconsistent node listsRickard Green
If net_kernel "forgets" to abort a connection (as it currently might), the garbage collection of a distribution entry could cause node lists to enter an inconsistent state.
2018-09-05Merge branch 'maint'Sverker Eriksson
2018-09-05Merge branch 'sverker/erts/ets-memstat-false-leak/ERL-720/OTP-15278' into maintSverker Eriksson
* sverker/erts/ets-memstat-false-leak/ERL-720/OTP-15278: erts: Refactor ets FixedDeletion allocations erts: Fix ets memstat false leak of FixedDeletion
2018-09-05Merge pull request #1947 from bjorng/bjorn/opt-put-tupleBjörn Gustavsson
Introduce a put_tuple2 instruction
2018-09-04Fix an endless rescheduling loop when a process is executing ↵Maxim Fedorov
process_info(self(), ...) It is possible that a process has to yield before completing process_info BIF when it runs out of reductions. If this BIF is called by the process itself, it does not send a signal but executes in the context of a process. If it has to yield, it turns F_LOCAL_SIGS_ONLY flag on, which means new signals won't be fetched from the outer message queue. When the same process needs to execute dirty system code (e.g. dirty GC) it has to be run on a dirty scheduler. However signals enqueued into outer queue cause it to be rescheduled on a normal scheduler. F_LOCAL_SIGS_ONLY prevent outer queue signals delivery, creating an endless rescheduling loop. This commit disengages F_LOCAL_SIG_ONLY if process needs to execute dirty code in order to complete signal delivery and allow process to be moved to dirty run queue.
2018-09-04Merge branch 'maint'Sverker Eriksson
2018-09-04Merge PR-1920 from saleyn/float_to_list OTP-15276Sverker Eriksson
Fix bug in compact representation of float_to_list/2
2018-09-04Implement socket option recvtos and friendsRaimo Niskanen
Implement socket options recvtclass, recvtos, recvttl and pktoptions. Document the implemented socket options, new types and message formats. The options recvtclass, recvtos and recvttl are boolean options that when activated (true) for a socket will cause ancillary data to be received through recvmsg(). That is for packet oriented sockets (UDP and SCTP). The required options for this feature were recvtclass and recvtos, and recvttl was only added to test that the ancillary data parsing handled multiple data items in one message correctly. These options does not work on Windows since ancillary data is not handled by the Winsock2 API. For stream sockets (TCP) there is no clear connection between a received packet and what is returned when reading data from the socket, so recvmsg() is not useful. It is possible to get the same ancillary data through a getsockopt() call with the IPv6 socket option IPV6_PKTOPTIONS, on Linux named IPV6_2292PKTOPTIONS after the now obsoleted RFC where it originated. (unfortunately RFC 3542 that obsoletes it explicitly undefines this way to get packet ancillary data from a stream socket) Linux also has got a way to get packet ancillary data for IPv4 TCP sockets through a getsockopt() call with IP_PKTOPTIONS, which appears to be Linux specific. This implementation uses a flag field in the inet_drv.c socket internal data that records if any setsockopt() call with recvtclass, recvtos or recvttl (IPV6_RECVTCLASS, IP_RECVTOS or IP_RECVTTL) has been activated. If so recvmsg() is used instead of recvfrom(). Ancillary data is delivered to the application by a new return tuple format from gen_udp:recv/2,3 containing a list of ancillary data tuples [{tclass,TCLASS} | {tos,TOS} | {ttl,TTL}], as returned by recvmsg(). For a socket in active mode a new message format, containing the ancillary data list, delivers the data in the same way. For gen_sctp the ancillary data is delivered in the same way, except that the gen_sctp return tuple format already contained an ancillary data list so there are just more possible elements when using these socket options. Note that the active mode message format has got an extra tuple level for the ancillary data compared to what is now implemented gen_udp. The gen_sctp active mode format was considered to be the odd one - now all tuples containing ancillary data are flat, except for gen_sctp active mode. Note that testing has not shown that Linux SCTP sockets deliver any ancillary data for these socket options, so it is probably not implemented yet. Remains to be seen what FreeBSD does... For gen_tcp inet:getopts([pktoptions]) will deliver the latest received ancillary data for any activated socket option recvtclass, recvtos or recvttl, on platforms where IP_PKTOPTIONS is defined for an IPv4 socket, or where IPV6_PKTOPTIONS or IPV6_2292PKTOPTIONS is defined for an IPv6 socket. It will be delivered as a list of ancillary data items in the same way as for gen_udp (and gen_sctp). On some platforms, e.g the BSD:s, when you activate IP_RECVTOS you get ancillary data tagged IP_RECVTOS with the TOS value, but on Linux you get ancillary data tagged IP_TOS with the TOS value. Linux follows the style of RFC 2292, and the BSD:s use an older notion. For RFC 2292 that defines the IP_PKTOPTIONS socket option it is more logical to tag the items with the tag that is the item's, than with the tag that defines that you want the item. Therefore this implementation translates all BSD style ancillary data tags to the corresponding Linux style data tags, so the application will only see the tags 'tclass', 'tos' and 'ttl' on all platforms.
2018-09-03erts: Refactor ets FixedDeletion allocationsSverker Eriksson
2018-09-03erts: Fix ets memstat false leak of FixedDeletionSverker Eriksson
causing erlang:memory to report too much ets memory.
2018-09-03Introduce a put_tuple2 instructionBjörn Gustavsson
Sometimes when building a tuple, there is no way to avoid an extra `move` instruction. Consider this code: make_tuple(A) -> {ok,A}. The corresponding BEAM code looks like this: {test_heap,3,1}. {put_tuple,2,{x,1}}. {put,{atom,ok}}. {put,{x,0}}. {move,{x,1},{x,0}}. return. To avoid overwriting the source register `{x,0}`, a `move` instruction is necessary. The problem doesn't exist when building a list: %% build_list(A) -> [A]. {test_heap,2,1}. {put_list,{x,0},nil,{x,0}}. return. Introduce a new `put_tuple2` instruction that builds a tuple in a single instruction, so that the `move` instruction can be eliminated: %% make_tuple(A) -> {ok,A}. {test_heap,3,1}. {put_tuple2,{x,0},{list,[{atom,ok},{x,0}]}}. return. Note that the BEAM loader already combines `put_tuple` and `put` instructions into an internal instruction similar to `put_tuple2`. Therefore the introduction of the new instruction will not speed up execution of tuple building itself, but it will be less work for the loader to load the new instruction.
2018-09-03Merge branch 'maint'Björn Gustavsson
* maint: ops.tab: Fix potentially unsafe optimization of raise/2
2018-09-03ops.tab: Fix potentially unsafe optimization of raise/2Björn Gustavsson
The operands for the raise/2 instruction are almost always in x(2) and x(1). Therefore the loader translates the raise/2 instruction to an i_raise/0 instruction which uses the values in x(2) and x(1). If the operands happens to be in other registers, the loader inserts move/2 instruction to move them to x(2) and x(1). The problem is that x(3) is used as a temporary register when generating the move/2 instructions. That is unsafe if the Value operand for raise/2 is x(3). Thus: raise x(0) x(3) will be translated to: move x(0) x(3) move x(3) x(1) move x(3) x(2) i_raise The Trace will be written to both x(2) and x(1). The current compiler will never use x(3) for the Value operand, so there is no need to patch previous releases. But a future compiler version might allocate registers differently.
2018-08-31Fix an endless rescheduling loop when a process is executing ↵Maxim Fedorov
process_info(self(), ...) It is possible that a process has to yield before completing process_info BIF when it runs out of reductions. If this BIF is called by the process itself, it does not send a signal but executes in the context of a process. If it has to yield, it turns F_LOCAL_SIGS_ONLY flag on, which means new signals won't be fetched from the outer message queue. When the same process needs to execute dirty system code (e.g. dirty GC) it has to be run on a dirty scheduler. However signals enqueued into outer queue cause it to be rescheduled on a normal scheduler. F_LOCAL_SIGS_ONLY prevent outer queue signals delivery, creating an endless rescheduling loop. This commit disengages F_LOCAL_SIG_ONLY if process needs to execute dirty code in order to complete signal delivery and allow process to be moved to dirty run queue.