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2019-01-07Spawn prim_file helper as a system processJohn Högberg
2018-11-21erts: Add counters:put/3Sverker Eriksson
2018-11-15erts: Add new module 'counters'Sverker Eriksson
2018-11-15erts: Add new module 'atomics'Sverker Eriksson
2018-11-06Add a persistent term storageBjörn Gustavsson
Persistent terms are useful for storing Erlang terms that are never or infrequently updated. They have the following advantages: * Constant time access. A persistent term is not copied when it is looked up. The constant factor is lower than for ETS, and no locks are taken when looking up a term. * Persistent terms are not copied in garbage collections. * There is only ever one copy of a persistent term (until it is deleted). That makes them useful for storing configuration data that needs to be easily accessible by all processes. Persistent terms have the following drawbacks: * Updates are expensive. The hash table holding the keys for the persistent terms are updated whenever a persistent term is added, updated or deleted. * Updating or deleting a persistent term triggers a "global GC", which will schedule a heap scan of all processes to search the heap of all processes for the deleted term. If a process still holds a reference to the deleted term, the process will be garbage collected and the term copied to the heap of the process. This global GC can make the system less responsive for some time. Three BIFs (implemented in C in the emulator) is the entire interface to the persistent term functionality: * put(Key, Value) to store a persistent term. * get(Key) to look up a persistent term. * erase(Key) to delete a persistent term. There are also two additional BIFs to obtain information about persistent terms: * info() to return a map with information about persistent terms. * get() to return a list of a {Key,Value} tuples for all persistent terms. (The values are not copied.)
2018-05-16Replace previous suspend in setnode/3Rickard Green
2018-05-16New process suspend implementation based on async signalingRickard Green
2018-04-23erts: Rewrite memory instrumentationJohn Högberg
This commit replaces the old memory instrumentation with a new implementation that scans carriers instead of wrapping erts_alloc/erts_free. The old implementation could not extract information without halting the emulator, had considerable runtime overhead, and the memory maps it produced were noisy and lacked critical information. Since the new implementation walks through existing data structures there's no longer a need to start the emulator with special flags to get information about carrier utilization/fragmentation. Memory fragmentation is also easier to diagnose as it's presented on a per-carrier basis which eliminates the need to account for "holes" between mmap segments. To help track allocations, each allocation can now be tagged with what it is and who allocated it at the cost of one extra word per allocation. This is controlled on a per-allocator basis with the +M<S>atags option, and is enabled by default for binary_alloc and driver_alloc (which is also used by NIFs).
2018-03-23Merge branch 'rickard/signals/OTP-14589'Rickard Green
* rickard/signals/OTP-14589: Fix VM probes compilation Fix lock counting Fix signal order for is_process_alive Fix signal handling priority elevation
2018-03-22Fix signal order for is_process_aliveRickard Green
2018-03-22Merge branch 'bjorn/erts/eliminate-get_stacktrace'Björn Gustavsson
* bjorn/erts/eliminate-get_stacktrace: Eliminate use of erlang:get_stacktrace/0 in preloaded modules
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.
2018-03-21Eliminate use of erlang:get_stacktrace/0 in preloaded modulesBjörn Gustavsson
2018-03-02erts,kernel: Add dist_util:strict_order_flags/0Sverker Eriksson
to replace DFLAGS_STRICT_ORDER_DELIVERY and remove that compile time dependency.
2018-03-02erts,kernel: Add erts_internal:get_dflags/0Sverker Eriksson
for kernel to ask erts about distribution flags and keep this info in one place.
2017-12-19Redirect system_flag(scheduler_wall_time,_) to kernel_refcRickard Green
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: 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.
2017-11-15Move new|abort_connection_id to erts_internalSverker Eriksson
and drop _id suffix.
2017-10-13erts: Implement maps path iteratorLukas Larsson
2017-08-28Support for distribution controller processesRickard Green
2017-05-04Update copyright yearRaimo Niskanen
2017-02-23erts: Introduce erts_internal:maps_to_list/2Björn-Egil Dahlberg
2016-11-02Merge branch 'maint'Hans Bolinder
* maint: Update preloaded erts: Correct type declaration of match specification head Conflicts: erts/preloaded/ebin/erlang.beam erts/preloaded/ebin/erts_internal.beam
2016-11-01erts: Correct type declaration of match specification headHans Bolinder
Bug reported by Peti Gömöri <[email protected]>.
2016-09-15Merge branch 'maint'Björn Gustavsson
* maint: erts: Add nif_SUITE:t_on_load erts: Improve nif_SUITE:upgrade test Don't leak old code when loading a modules with an on_load function Conflicts: erts/preloaded/ebin/erts_code_purger.beam erts/preloaded/ebin/erts_internal.beam erts/preloaded/src/erts_code_purger.erl
2016-09-14Don't leak old code when loading a modules with an on_load functionBjörn Gustavsson
Normally, calling code:delete/1 before re-loading the code for a module is unnecessary but causes no problem. But there will be be problems if the new code has an on_load function. Code with an on_load function will always be loaded as old code to allowed it to be easily purged if the on_load function would fail. If the on_load function succeeds, the old and current code will be swapped. So in the scenario where code:delete/1 has been called explicitly, there is old code but no current code. Loading code with an on_load function will cause the reference to the old code to be overwritten. That will at best cause a memory leak, and at worst an emulator crash (especially if NIFs are involved). To avoid that situation, we will put the code with the on_load function in a special, third slot in Module. ERL-240
2016-09-06Merge branch 'kvakvs/erts/gc_minor_option/OTP-11695'Lukas Larsson
* kvakvs/erts/gc_minor_option/OTP-11695: erts: Fix req_system_task gc typespec Fix process_SUITE system_task_blast and no_priority_inversion2 Option to erlang:garbage_collect to request minor (generational) GC Conflicts: erts/emulator/beam/erl_process.c erts/preloaded/src/erts_internal.erl
2016-09-06erts: Fix req_system_task gc typespecLukas Larsson
2016-08-31Remove old purge strategyRickard Green
2016-08-29Perform check_process_code while process is executing dirtyRickard Green
2016-08-29Fix purge of codeRickard Green
Ensure that we cannot get any dangling pointers into code that has been purged. This is done by a two phase purge. At first phase all fun entries pointing into the code to purge are marked for purge. All processes trying to call these funs will be suspended and by this we avoid getting new direct references into the code. When all processes has been checked, these processes are resumed. The new purge strategy now also completely ignore the existence of indirect references to the code (funs). If such exist, they will cause bad fun exceptions to the caller, but will not prevent a soft purge or cause a kill of a process having such live references during a hard purge. This since it is impossible to give any guarantees that no processes in the system have such indirect references. Even when the system is completely clean from such references, new ones can appear via distribution and/or disk.
2016-08-26Reclaim literal area after purge has completedRickard Green
2016-08-12Option to erlang:garbage_collect to request minor (generational) GCDmytro Lytovchenko
Note: Minor GC option is a hint, and GC may still decide to run fullsweep. Test case for major and minor gc on self Test case for major and minor gs on some other process + async gc test check docs fix
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
2016-02-25Merge branch 'maint'Björn-Egil Dahlberg
Conflicts: erts/emulator/beam/erl_alloc.types erts/emulator/beam/erl_bif_info.c erts/emulator/beam/erl_process.c erts/preloaded/ebin/erts_internal.beam
2016-02-16erts: Add BIF erts_internal:system_check/1Björn-Egil Dahlberg
This commit implements erts_internal:system_check(schedulers) with the intent of a basic responsiveness test check of the schedulers.
2016-02-08Merge branch 'sverk/safe-purging/OTP-13122'Sverker Eriksson
* sverk/safe-purging/OTP-13122: erts: Fix harmless dialyzer warnings
2016-02-02erts: Add microstate accountingLukas Larsson
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. Since checking whether microstate accounting is on or off is relatively expensive if done in a short loop only a few of the states are enabled by default and more states can be enabled through configure. I've done some benchmarking and the overhead with it turned off is not noticible and with it on it is a fraction of a percent. If you enable the extra states, depending on the benchmark, the ovehead when turned off is about 1% and when turned on somewhere inbetween 5-15%. OTP-12345
2016-02-02erts, kernel: Add os:perf_counter functionLukas Larsson
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. A special instruction has been created for this counter to further speed up fetching it. OTP-12908
2016-01-25erts: Fix harmless dialyzer warningsSverker Eriksson
2016-01-13erts: Optimize erlang:check_process_codeSverker Eriksson
by ignoring literals. erts_internal:check_process_code will be called again anyway (with option {copy_literals, true}) before the module is actually purged. No need to check literals twice.
2016-01-13erts: Refactor check_process_code/3Sverker Eriksson
Move impl from erlang to erts_internal. Cut and paste.
2016-01-13erts: Move copy_literals/2 from erlang to erts_internalSverker Eriksson
as it's not a public interface.
2016-01-13erts: Make erlang:purge_module/1 safeSverker Eriksson
Problem: erlang:purge_module/1 is not safe in the sense that very bad things may happen if the code to be purged is still referred to by live processes. Introduce erts_internal:purge_module which is the same as the old erlang:purge_module BIF (except it returns false if no such old module). Implement erlang:purge_module in Erlang and let it invoke erts_code_purger for safe purging where all clogging processes first are killed.
2015-12-15Merge branch 'lukas/erts/forker'Lukas Larsson
* lukas/erts/forker: (28 commits) erts: Never abort in the forked child erts: Mend ASSERT makro for erl_child_setup erts: Allow enomem failures in port_SUITE erts: iter_port sleep longer on freebsd erts: Allow one dangling fd if there is a gethost port erts: Only use forker StackAck on freebsd erts: It is not possible to exit the forker driver erts: Add forker StartAck for port start flowcontrol erts: Fix large open_port arg segfault for win32 erts: Fix memory leak at async open port kernel: Remove cmd server for unix os:cmd erts: Add testcase for huge port environment erts: Move os_pid to port hash to child setup erts: Handle all EINTR and EAGAIN cases in child setup erts: Make child_setup work with large environments erts: Fix forker driver ifdefs for win32 erts: Fix uds socket handling for os x erts: Fix dereferencing of unaligned integer for sparc erts: Flatten too long io vectors in uds write erts: Add fd count test for spawn_driver ... Conflicts: erts/emulator/beam/erl_node_tables.c erts/preloaded/src/erts_internal.erl
2015-12-15erts: Add support for asynchronous open_portLukas Larsson
OTP-13086
2015-12-07erts: Let term_type/1 encompass all typesBjörn-Egil Dahlberg