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2018-01-03Replace the libc environment with a thread-safe emulationJohn Högberg
putenv(3) and friends aren't thread-safe regardless of how you slice it; a global lock around all environment operations (like before) keeps things safe as far as our own operations go, but we have absolutely no control over what libc or a library dragged in by a driver/NIF does -- they're free to call getenv(3) or putenv(3) without honoring our lock. This commit solves this by setting up an "emulated" environment which can't be touched without going through our interfaces. Third-party libraries can still shoot themselves in the foot but benign uses of os:putenv/2 will no longer risk crashing the emulator.
2017-12-06"Fix" tracing of dirty NIFs on debug buildsJohn Högberg
When a dirty NIF is executed a "schedule in" trace event is generated, which may in turn result in a generic system task being created, causing the process to be scheduled out as it can't run dirty with pending tasks. This is usually fine since said system task is seldom created, but ERTS_FORCE_ENIF_SEND_DELAY was de-facto always on for debug builds, causing the process to bounce between dirty and normal schedulers forever. This commit is not a complete fix and it can go off the rails even on normal builds; if there's a lot of dirty jobs lined up and the receiver's msgq lock happens to be busy at the wrong time, the additional trace messages generated through this will hammer the lock and keep everything bouncing.
2017-12-05Merge branch 'maint'John Högberg
2017-12-05Merge branch 'john/erts/lcnt-fix-reg-proc-names/OTP-14803' into maintJohn Högberg
2017-12-04Fix process name resolution in lcnt resultsJohn Högberg
2017-12-04Merge branch 'bjorn/compiler/clean-up-codegen'Björn Gustavsson
* bjorn/compiler/clean-up-codegen: bs_match_SUITE: Cover more clauses in v3_codegen:bs_rename_ctx/4 Clean up and comment code generation for basic blocks Stop trying to maximize the use of x(0) Clean up collection of basic blocks
2017-11-30Remove all mention of efile_drv from DTrace docsJohn Högberg
efile_drv is gone and so is the need for file-specific DTrace. The new implementation works fine with the normal tracing mechanism so there's nothing preventing anyone from making an erl_tracer nif that forward these events to DTrace.
2017-11-30Reimplement efile_drv as a dirty NIFJohn Högberg
This improves the latency of file operations as dirty schedulers are a bit more eager to run jobs than async threads, and use a single global queue rather than per-thread queues, eliminating the risk of a job stalling behind a long-running job on the same thread while other async threads sit idle. There's no such thing as a free lunch though; the lowered latency comes at the cost of increased busy-waiting which may have an adverse effect on some applications. This behavior can be tweaked with the +sbwt flag, but unfortunately it affects all types of schedulers and not just dirty ones. We plan to add type-specific flags at a later stage. sendfile has been moved to inet_drv to lessen the effect of a nasty race; the cooperation between inet_drv and efile has never been airtight and the socket dying at the wrong time (Regardless of reason) could result in fd aliasing. Moving it to the inet driver makes it impossible to trigger this by closing the socket in the middle of a sendfile operation, while still allowing it to be aborted -- something that can't be done if it stays in the file driver. The race still occurs if the controlling process dies in the short window between dispatching the sendfile operation and the dup(2) call in the driver, but it's much less likely to happen now. A proper fix is in the works. -- Notable functional differences: * The use_threads option for file:sendfile/5 no longer has any effect. * The file-specific DTrace probes have been removed. The same effect can be achieved with normal tracing together with the nif__entry/nif__return probes to track scheduling. -- OTP-14256
2017-11-30Change resource_monitors' lock orderJohn Högberg
If a NIF monitor fired while the resource was present in an ETS table, the lock checker would erroneously report a lock order violation. This has no effect outside of debug builds.
2017-11-30Add enif_ioq_peek_headJohn Högberg
This introduces a way to retrieve erlang terms from NIF IO queues without having to resort to copying. OTP-14797
2017-11-30Stop trying to maximize the use of x(0)Björn Gustavsson
X register 0 used to be mapped to a hardware register, and therefore faster than the other registers. Because of that, the compiler tried to use x(0) as much as possible as a temporary register. That was changed a few releases ago. X register 0 is now placed in the array of all X registers and has no special speed advantage compared to the other registers. Remove the code in the compiler that attempts to use x(0) as much as possible. As a result, the following type of instruction will be much less frequent: {put_list,Src,{x,0},{x,0}} Instead, the following type of instruction will be more frequent: {put_list,Src,{x,X},{x,X}} (Where X is an arbitrary X register.) Update the runtime system to specialize that kind of put_list instruction.
2017-11-30Merge branch 'maint'Björn Gustavsson
* maint: Fix max atom size overflow on 64-bits Erlang by lowering the MAX_ATOM_TABLE_SIZE Fix integer overflow when set a large maximum value for atom table
2017-11-30Merge pull request #1633 from sunboshan/atom-size-fixBjörn Gustavsson
Fix integer overflow when set a large maximum value for atom table OTP-14796
2017-11-27erts: Fix bad merge of PR #1644Björn Gustavsson
2017-11-27Merge branch 'maint'John Högberg
2017-11-27Merge branch 'john/erts/fix-nif-ioq-version/OTP-14779' into maintJohn Högberg
2017-11-24Fix purging of modules with "fake literals"Björn Gustavsson
When compiling Erlang source code, the literal area for the module can only contain data types that have a literal syntax. However, it is possible to sneak in other data types (such as references) in the literal pool by compiling from abstract or assembly code. Those "fake literals" would work fine, but would crash the runtime system when the module containing the literals was purged. Although fake literals are not officially supported, the runtime should not crash when attempting to use them. Therefore, fix the garbage collection of literals and releasing of literal areas. https://bugs.erlang.org/browse/ERL-508
2017-11-24Merge branch 'maint'Björn Gustavsson
* maint: Use base64 encoding in crash dumps Correct parsing of sub binaries Generalize passing of options for decoding
2017-11-24Merge branch 'bjorn/base64-in-dumps/OTP-14686' into maintBjörn Gustavsson
* bjorn/base64-in-dumps/OTP-14686: Use base64 encoding in crash dumps Correct parsing of sub binaries Generalize passing of options for decoding
2017-11-23Merge branch 'sverker/async-auto-connect/OTP-14370' AGAINSverker Eriksson
2017-11-23erts: Fix erlang:monitor toward c-nodesSverker Eriksson
by suppressing DOP_MONITOR_P, DOP_MONITOR_P_EXIT and DOP_DEMONITOR_P if not supported by the remote node. In 17e198d6ee60f7dec9abfed272cf4226aea44535 I changed the behavior of erlang:monitor to not raise badarg for c-nodes but instead create a monitor to only supervise the connection. But I forgot to prevent DOP_MONITOR_P and friends from being sent to the node that does not expect them. Note: We test both DFLAG_DIST_MONITOR and DFLAG_DIST_MONITOR_NAME for the node to support process monitoring. This is because erl_interface is buggy as it sets DFLAG_DIST_MONITOR without really supporting it. ToDo: Should erl_interface stop setting DFLAG_DIST_MONITOR or should we change the meaning of these flags?
2017-11-21Merge branch 'maint'Sverker Eriksson
2017-11-21Merge branch 'sverker/nif-debug-bin-check' into maintSverker Eriksson
2017-11-21erts: Fix preemption bug in erts_dist_commandSverker Eriksson
We should break out when out of reductions.
2017-11-21erts: Remove obsolete commentsSverker Eriksson
2017-11-21Use base64 encoding in crash dumpsBjörn Gustavsson
This will reduce the size of crash dumps, especially if there are large binaries.
2017-11-20Fix max atom size overflow on 64-bits Erlang by lowering theBoshan Sun
MAX_ATOM_TABLE_SIZE Currently, the max atom size on 64-bits Erlang is ((UWORD_CONSTANT(1) << 32) = 4294967296 This number will cause the range of atom size to be displayed as [8192-0]. Also, the +t option for max atom size will be parsed as a long type, and assigned to a int variable erts_atom_table_size (erl_init.c), which will cause integer overflow if the number is larger than the maximum value a 4-bytes signed integer can hold ((1 << 31) - 1) = 2147483647 Therefore, during the comparison erts_atom_table_size < MIN_ATOM_TABLE_SIZE any number above 2147483647 will be come negative, and causing the condition to be true, which then errored out as bad atom table size. Hence, the actual max atom size is same as the max signed int value.
2017-11-20Fix integer overflow when set a large maximum value for atom tableBoshan Sun
When setting maximum atom table size using +t option, there will be a integer overflow for a large size. $ erl +t2147482625 ll_alloc: Cannot allocate 18446744073692774400 bytes of memory (of type "atom_tab"). The overflow is caused by the arithmetic operations on int type. When 2147482625 + 1024 it will become -2147483647 due to the signed integerger overflow. Then the result will be resized to Uint type, which is a unsigned long type, the negative int will first be expand to 64 bits long via sign extension, then change to unsigned type, which becomes 18446744073692774400. The fix is done by convert `limit` to Uint type before doing any arithmetic operation. This will expand variable to 64 bits long type via zero extension, then the following operation are all positive, therefore no overflow will happen. Note: here we assume the int `limit` passed in is always positive. If some future change cause the `limit` passed in maybe negative, then the current fix will also cause overflow.
2017-11-20Merge branch 'lukas/stdlib/maps_iterators/OTP-14012'Lukas Larsson
* lukas/stdlib/maps_iterators/OTP-14012: erts: Limit size of first iterator for hashmaps Update primary bootstrap Update preloaded modules erts: Remove erts_internal:maps_to_list/2 stdlib: Make io_lib and io_lib_pretty use maps iterator erts: Implement batching maps:iterator erts: Implement maps path iterator erts: Implement map iterator using a stack stdlib: Introduce maps iterator API Conflicts: bootstrap/lib/stdlib/ebin/io_lib.beam bootstrap/lib/stdlib/ebin/io_lib_pretty.beam erts/emulator/beam/bif.tab erts/preloaded/ebin/erlang.beam erts/preloaded/ebin/erts_internal.beam erts/preloaded/ebin/zlib.beam
2017-11-20erts: Limit size of first iterator for hashmapsLukas Larsson
2017-11-20erts: Remove erts_internal:maps_to_list/2Lukas Larsson
This function is no longer needed as maps:iterator has now been implemented.
2017-11-20erts: Implement batching maps:iteratorLukas Larsson
This iterator implementation fetches multiple elements to iterate over in one call to erts_internal:maps_next instead of one at a time. This means that the memory usage will go up for the iterator as we are buffering elements, but the usage is still bounded. In this implementation the max memory usage is 1000 words. Using this approach makes the iterator as fast as using maps:to_list, so maps:iterator/2 has been removed.
2017-11-17Merge branch 'sverker/async-auto-connect/OTP-14370'Sverker Eriksson
* sverker/async-auto-connect/OTP-14370: (37 commits) Move new|abort_connection_id to erts_internal Refactor erts_dsig_prepare argument dep(p) Cleanup net_kernel Improve connection aborting Abort all pending connections if net_kernel terminates erts: Put pending DistrEntry in separate list Refactor auto_connect into an outline function Remove unused ERTS_DSP_RWLOCK fix erlang specs and preloaded erts: Keep magic ref to DistEntry in net_kernel Allow DistEntries in ETS Remove faulty assert erts: Transcode tuple fallbacks erts: Ensure enc_term_int() always do progress erl_interface: Add tuple fallback tests erl_interface: Refactor ei_accept_SUITE Add optimistic DFLAG_DIST_HOPEFULLY for pending connections erts: Fix auto-connect toward erl_interface/jinterface erts: Let send(_,_,[noconnect]) enqueue msg on pending connection. Remove obsolete erlang:dgroup_leader ...
2017-11-16Fix triggering of node monitorsRickard Green
2017-11-16Merge branch 'maint'Rickard Green
* maint: Fix triggering of node monitors Conflicts: erts/emulator/beam/dist.c
2017-11-16Merge branch 'rickard/node-mon-proc-exit-race/OTP-14781' into maintRickard Green
* rickard/node-mon-proc-exit-race/OTP-14781: Fix triggering of node monitors
2017-11-16Merge pull request #1626 from bjorng/bjorn/erts/fix-receive-opt/ERL-511Björn Gustavsson
Fix broken receive mark after an exception OTP-14782
2017-11-15Move new|abort_connection_id to erts_internalSverker Eriksson
and drop _id suffix.
2017-11-15Refactor erts_dsig_prepare argument dep(p)Sverker Eriksson
Don't need to be pointer-pointer
2017-11-15Improve connection abortingSverker Eriksson
2017-11-15Abort all pending connections if net_kernel terminatesSverker Eriksson
2017-11-15erts: Put pending DistrEntry in separate listSverker Eriksson
2017-11-15Refactor auto_connect into an outline functionSverker Eriksson
and abort_pending_connection into own utility function.
2017-11-15Remove unused ERTS_DSP_RWLOCKSverker Eriksson
2017-11-15erts: Keep magic ref to DistEntry in net_kernelSverker Eriksson
to make sure it's kept alive.
2017-11-15Allow DistEntries in ETSSverker Eriksson
2017-11-15Remove faulty assertSverker Eriksson
Send may have failed, port exit with dist_entry cleaned up and then new pending connection with queued messages.
2017-11-15erts: Transcode tuple fallbacksSverker Eriksson
When finalizing outgoing distribution messages we transcode them into using tuple fallbacks if the receiver does not support bitstrings and export-funs. This can only happen if the message was first encoded toward a pending connection when the receiver was unknown. It's an optimistic approach optmimized for modern beam nodes, that expect real bitstrings and funs (since <R13). Only erl_interface/jinterface lack this support.
2017-11-15erts: Ensure enc_term_int() always do progressSverker Eriksson
even when reds <= 1 Removed micro optimization for first fun variable to make things simpler.
2017-11-15Add optimistic DFLAG_DIST_HOPEFULLY for pending connectionsSverker Eriksson
to avoid tuple fallbacks for export funs and bitstrings. ToDo: Re-encode if receiver turn out to be erl_interface/jinterface.