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2019-02-22erts: Add ERL_NODE_BOOKKEEP to node tables refcLukas Larsson
2019-01-15Merge branch 'maint'Lukas Larsson
2019-01-15erts: Make sure to take main lock when dumping proc infoLukas Larsson
If the main lock is not taken then any process running on a dirty scheduler may cause all kinds of problems.
2018-12-18Make length/1 yieldingBjörn Gustavsson
The guard BIF `length/1` would calculate the length of the list in one go without yielding, even if the list was were long. To make it even worse, the call to `length/1` would only cost a single reduction. This commit reimplements `length/1` so that it eats a number of reductions proportional to the length of the list, and yields if the available reductions run out.
2018-09-07erts: Beautify away #ifdef DEBUGSverker Eriksson
"(void)result" will silence warning about unused variable and compiler will optimize away such unused variables.
2018-06-04erts: Refactor usage of am_atom_put to ERTS_MAKE_AMSverker Eriksson
and let compiler determine string lengths. These were actually wrong in erl_db.c: count_trap\0 replace_tra select_tra
2018-05-18Merge branch 'sverker/ets-delete_all_objects-trap/OTP-15078'Sverker Eriksson
* sverker/ets-delete_all_objects-trap/OTP-15078: erts: Rename untrapping db_free_*empty*_table erts: Make ets:delete_all_objects yield on fixed table erts: Optimize ets delete all in fixed table erts: Refactor ets select iteration code erts: Cleanup ets code erts: Optimize ets hash object deallocactions erts: Refactor pseudo deleted ets objects erts: Make atomic ets:delete_all_objects yield erts: Fix reduction bump for ets:delete/1
2018-05-08erts: Cleanup ets codeSverker Eriksson
2018-04-29Introduce is_map_key/2 guard BIFMichał Muskała
This complements the `map_get/2` guard BIF introduced in #1784. Rationale. `map_get/2` allows accessing map fields in guards, but it might be problematic in more complex guard expressions, for example: foo(X) when map_get(a, X) =:= 1 or is_list(X) -> ... The `is_list/1` part of the guard could never succeed since the `map_get/2` guard would fail the whole guard expression. In this situation, this could be solved by using `;` instead of `or` to separate the guards, but it is not possible in every case. To solve this situation, this PR proposes a `is_map_key/2` guard that allows to check if a map has key inside a guard before trying to access that key. When combined with `is_map/1` this allows to construct a purely boolean guard expression testing a value of a key in a map. Implementation. Given the use case motivating the introduction of this function, the PR contains compiler optimisations that produce optimial code for the following guard expression: foo(X) when is_map(X) and is_map_key(a, X) and map_get(a, X) =:= 1 -> ok; foo(_) -> error. Given all three tests share the failure label, the `is_map_key/2` and `is_map/2` tests are optimised away. As with `map_get/2` the `is_map_key/2` BIF is allowed in match specs.
2018-04-24Introduce map_get guard-safe functionMichał Muskała
Rationale Today all compound data types except for maps can be deconstructed in guards. For tuples we have `element/2` and for lists `hd/1` and `tl/1`. Maps are completely opaque to guards. This means matching on maps can't be abstracted into macros, which is often done with repetitive guards. It also means that maps have to be always selected whole from ETS tables, even when only one field would be enough, which creates a potential efficiency issue. This PR introduces an `erlang:map_get/2` guard-safe function that allows extracting a map field in guard. An alternative to this function would be to introduce the syntax for extracting a value from a map that was planned in the original EEP: `Map#{Key}`. Even outside of guards, since this function is a guard-BIF it is more efficient than using `maps:get/2` (since it does not need to set up the stack), and more convenient from pattern matching on the map (compare: `#{key := Value} = Map, Value` to `map_get(key, Map)`). Performance considerations A common concern against adding this function is the notion that "guards have to be fast" and ideally execute in constant time. While there are some counterexamples (`length/1`), what is more important is the fact that adding those functions does not change in any way the time complexity of pattern matching - it's already possible to match on map fields today directly in patterns - adding this ability to guards will niether slow down or speed up the execution, it will only make certain programs more convenient to write. This first version is very naive and does not perform any optimizations.
2018-03-23Lift the type restrictions on seq_trace token labelsJohn Högberg
OTP-14899
2018-03-21Merge pull request #1740 from rickard-green/rickard/signals/OTP-14589Rickard Green
Implementation of true asynchronous signaling between processes
2018-03-21Implementation of true asynchronous signaling between processesRickard Green
Communication between Erlang processes has conceptually always been performed through asynchronous signaling. The runtime system implementation has however previously preformed most operation synchronously. In a system with only one true thread of execution, this is not problematic (often the opposite). In a system with multiple threads of execution (as current runtime system implementation with SMP support) it becomes problematic. This since it often involves locking of structures when updating them which in turn cause resource contention. Utilizing true asynchronous communication often avoids these resource contention issues. The case that triggered this change was contention on the link lock due to frequent updates of the monitor trees during communication with a frequently used server. The signal order delivery guarantees of the language makes it hard to change the implementation of only some signals to use true asynchronous signaling. Therefore the implementations of (almost) all signals have been changed. Currently the following signals have been implemented as true asynchronous signals: - Message signals - Exit signals - Monitor signals - Demonitor signals - Monitor triggered signals (DOWN, CHANGE, etc) - Link signals - Unlink signals - Group leader signals All of the above already defined as asynchronous signals in the language. The implementation of messages signals was quite asynchronous to begin with, but had quite strict delivery constraints due to the ordering guarantees of signals between a pair of processes. The previously used message queue partitioned into two halves has been replaced by a more general signal queue partitioned into three parts that service all kinds of signals. More details regarding the signal queue can be found in comments in the erl_proc_sig_queue.h file. The monitor and link implementations have also been completely replaced in order to fit the new asynchronous signaling implementation as good as possible. More details regarding the new monitor and link implementations can be found in the erl_monitor_link.h file.
2018-03-20erts: Optimize macro DMC_PUSHSverker Eriksson
to call a common static function dmc_stack_grow() and reduce the code bloat. and did a combined DMC_PUSH2
2018-03-09Always use sys_memcpy/cmp/etc instead of plain memcpy/cmp/etcJohn Högberg
2017-07-17erts: Replace usage of all erts_smp prefixes to just ertsLukas Larsson
2017-07-17erts: Remove ERTS_SMP and USE_THREAD definesLukas Larsson
This refactor was done using the unifdef tool like this: for file in $(find erts/ -name *.[ch]); do unifdef -t -f defile -o $file $file; done where defile contained: #define ERTS_SMP 1 #define USE_THREADS 1 #define DDLL_SMP 1 #define ERTS_HAVE_SMP_EMU 1 #define SMP 1 #define ERL_BITS_REENTRANT 1 #define ERTS_USE_ASYNC_READY_Q 1 #define FDBLOCK 1 #undef ERTS_POLL_NEED_ASYNC_INTERRUPT_SUPPORT #define ERTS_POLL_ASYNC_INTERRUPT_SUPPORT 0 #define ERTS_POLL_USE_WAKEUP_PIPE 1 #define ERTS_POLL_USE_UPDATE_REQUESTS_QUEUE 1 #undef ERTS_HAVE_PLAIN_EMU #undef ERTS_SIGNAL_STATE
2017-05-16Merge branch 'lukas/erts/trace_recv_esdp_bug/OTP-14411'Lukas Larsson
* lukas/erts/trace_recv_esdp_bug/OTP-14411: erts: the esdp is not always available in matchspec
2017-05-16Merge pull request #1436 from garazdawi/lukas/erts/remove_unused_functionsLukas Larsson
erts: Remove old unused functions
2017-05-16erts: Remove old unused functionsLukas Larsson
The functions have been found using: https://github.com/caolanm/callcatcher
2017-05-10Merge branch 'sverker/ets-select-replace-const'Sverker Eriksson
* sverker/ets-select-replace-const: stdlib: Add examples for ets:select_replace docs erts: Fix ets:select_replace with {const, NewTuple}
2017-05-10erts: Fix ets:select_replace with {const, NewTuple}Sverker Eriksson
Enable ets:select_replace to do a generic single object compare-and-swap operation of any ets-tuple using a matchspec like this: [{Old, [], [{const, New}]}] The only exception when this does not work is if the key contains maps or atoms looking like variables (like '$1').
2017-05-05erts: the esdp is not always available in matchspecLukas Larsson
This happens for instance when a receive_trace is run in the sys_msg_dispatcher thread when the trace_delivered trace message is traced.
2017-05-04Update copyright yearRaimo Niskanen
2017-04-11erts: Introduce erts_bin_releaseSverker Eriksson
2017-03-22erts: Optimize ets:select_replace to not use heapSverker Eriksson
for temporary matchspec results. ToDo: Would be even nicer if PAM could allocate and build the ETS objects without extra copy_struct needed.
2017-03-22erts: Fix benign bug in match spec machineSverker Eriksson
Looks like this line has truly been dead code as ets has (so far) always been using ERTS_PAM_COPY_RESULT and matchPushExpr is not generated for tracing.
2017-03-22Add more complete key-safety checkSverker Eriksson
2017-03-22Reject unsafe matchspecs on ets:select_replace/2Guilherme Andrade
Preemptively fail operation with badarg if the replacement object might have a different key.
2017-02-16Handle magic refs in db_cleanup_offheap_comp()Rickard Green
2017-02-14erts: Add deallocation veto for magic destructorsSverker Eriksson
A magic destructor can return 0 and thereby take control and prolong the lifetime of a magic binary.
2017-02-06Use magic refs for compiled match specsRickard Green
2017-02-06Implement magic referencesRickard Green
Magic references are *intentionally* indistinguishable from ordinary references for the Erlang software. Magic references do not change the language, and are intended as a pure runtime internal optimization. An ordinary reference is typically used as a key in some table. A magic reference has a direct pointer to a reference counted magic binary. This makes it possible to implement various things without having to do lookups in a table, but instead access the data directly. Besides very fast lookups this can also improve scalability by removing a potentially contended table. A couple of examples of planned future usage of magic references are ETS table identifiers, and BIF timer identifiers. Besides future optimizations using magic references it should also be possible to replace the exposed magic binary cludge with magic references. That is, magic binaries that are exposed as empty binaries to the Erlang software.
2017-02-06Merge branch 'maint'Rickard Green
* maint: Atomic reference count of binaries also in non-SMP Conflicts: erts/emulator/beam/erl_fun.c
2017-02-06Atomic reference count of binaries also in non-SMPRickard Green
NIF resources was not handled in a thread-safe manner in the runtime system without SMP support. As a consequence of this fix, the following driver functions are now thread-safe also in the runtime system without SMP support: - driver_free_binary() - driver_realloc_binary() - driver_binary_get_refc() - driver_binary_inc_refc() - driver_binary_dec_refc()
2016-10-12erts: Refactor find_function_from_pc to return MFALukas Larsson
2016-10-12erts: Refactor out func_info into structLukas Larsson
This commit adds two new structs to be used to represent erlang code in erts. ErtsCodeInfo is used to describe the i_func_info header that is part of all Export entries and the prelude of each function. This replaces all the BeamInstr * that were previously used to point to these locations. After this change the code should never use BeamInstr * with offsets to figure out different parts of the func_info header. ErtsCodeMFA is a struct that is used to descripe a MFA in code. It is used within ErtsCodeInfo and also in Process->current. All function that previously took Eterm * or BeamInstr * to identify a MFA now use the ErtsCodeMFA or ErtsCodeInfo where appropriate. The code has been tested to work when adding a new field to the ErtsCodeInfo struct, but some updates are needed in ops.tab to make it work.
2016-05-11erts: Only allow remove from trace_status callbackLukas Larsson
Make it so that it is only possible to remove a tracer via returning remove from an erl_tracer. This limition is put in place in order to avoid a lot of lock checking and taking in various places, especially in regards to trace events happening on dirty schedulers.
2016-05-11Add better support for communication with a process executing dirty NIFRickard Green
- Termination of a process... - Modify trace flags of process... - Process info on process... - Register/unregister of name on process... - Set group leader on process... ... while it is executing a dirty NIF.
2016-05-04erts: Fix bug in trace_pattern for 'on_load'Sverker Eriksson
'on_load' is a call trace.
2016-05-04erts: Fix PAM to be callable from non-scheduler threadSverker Eriksson
also simplified the interface to to run PAM from trace
2016-05-04erts: Add Sender in 'receive' trace matchspecSverker Eriksson
All 'EXIT' and monitor messages are sent from 'system' Timeouts are "sent" from 'clock_service'
2016-05-04erts: Add matchspec restrictions for 'receive' traceSverker Eriksson
and non-call-trace. This is the easy way out to avoid difficult locking scenarios when accessing tracing flags on another process.
2016-05-04erts: Add matchspec to 'receive' traceSverker Eriksson
2016-05-04erts: Remove multi scheduler blocking in match specsSverker Eriksson
for enable_trace and disable_trace operations. Instead seize needed locks while updating trace flags.
2016-04-15erts: Implement tracer modulesLukas Larsson
Add the possibility to use modules as trace data receivers. The functions in the module have to be nifs as otherwise complex trace probes will be very hard to handle (complex means trace probes for ports for example). This commit changes the way that the ptab->tracer field works from always being an immediate, to now be NIL if no tracer is present or else be the tuple {TracerModule, TracerState} where TracerModule is an atom that is later used to lookup the appropriate tracer callbacks to call and TracerState is just passed to the tracer callback. The default process and port tracers have been rewritten to use the new API. This commit also changes the order which trace messages are delivered to the potential tracer process. Any enif_send done in a tracer module may be delayed indefinitely because of lock order issues. If a message is delayed any other trace message send from that process is also delayed so that order is preserved for each traced entity. This means that for some trace events (i.e. send/receive) the events may come in an unintuitive order (receive before send) to the trace receiver. Timestamps are taken when the trace message is generated so trace messages from differented processes may arrive with the timestamp out of order. Both the erlang:trace and seq_trace:set_system_tracer accept the new tracer module tracers and also the backwards compatible arguments. OTP-10267
2016-03-15update copyright-yearHenrik Nord
2016-02-24Merge branch 'master' into sverk/master/halt-INT_MINSverker Eriksson
2016-02-24erts: Change erl_exit into erts_exitSverker Eriksson
This is mostly a pure refactoring. Except for the buggy cases when calling erlang:halt() with a positive integer in the range -(INT_MIN+2) to -INT_MIN that got confused with ERTS_ABORT_EXIT, ERTS_DUMP_EXIT and ERTS_INTR_EXIT. Outcome OLD erl_exit(n, ) NEW erts_exit(n, ) ------- ------------------- ------------------------------------------- exit(Status) n = -Status <= 0 n = Status >= 0 crashdump+abort n > 0, ignore n n = ERTS_ERROR_EXIT < 0 The outcome of the old ERTS_ABORT_EXIT, ERTS_INTR_EXIT and ERTS_DUMP_EXIT are the same as before (even though their values have changed).
2015-11-19Refactor have seq_trace token testBjörn-Egil Dahlberg