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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 The previously used message queue partitioned into two halves has been replaced by a more general signal queue partitioned into three parts that service all kinds of signals.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.
2017-05-04Update copyright yearRaimo Niskanen
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.
2016-11-17erts: Refactor crash dumping with cbprintfSverker Eriksson
Instead of passing around a file descriptor use a function pointer to facilitate more advanced backend write logic such as size limitation or compression.
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).
2016-01-07Merge branch 'sverk/proc-dict-opt'Sverker Eriksson
OTP-13167 * sverk/proc-dict-opt: erts: Add new test case pdict_SUITE:mixed erts: Add 'fill_heap' to erts_debug:state_internal_state erts: Rename proc dict size to arraySize erts: Refactor proc dict with 'usedSlots' erts: Add sizeMask for faster proc dict indexing erts: Remove ProcDict.used erts: Add proc dict macros ERTS_PD_START/SIZE erts: Optimize away function "array_put" in proc dict erts: Optimize hashing in process dictionary
2015-12-09erts: Add proc dict macros ERTS_PD_START/SIZESverker Eriksson
2015-11-12Merge branch 'rickard/ohmq/OTP-13047'Rickard Green
* rickard/ohmq/OTP-13047: Fragmented young heap generation and off_heap_message_queue option Refactor GC Introduce literal tag Conflicts: erts/doc/src/erlang.xml erts/emulator/beam/erl_gc.c
2015-11-12Fragmented young heap generation and off_heap_message_queue optionRickard Green
* The youngest generation of the heap can now consist of multiple blocks. Heap fragments and message fragments are added to the youngest generation when needed without triggering a GC. After a GC the youngest generation is contained in one single block. * The off_heap_message_queue process flag has been added. When enabled all message data in the queue is kept off heap. When a message is selected from the queue, the message fragment (or heap fragment) containing the actual message is attached to the youngest generation. Messages stored off heap is not part of GC.
2015-09-07Merge branch 'maint'Sverker Eriksson
2015-09-02Merge branch 'maint' into sverk/trace-process_dump-matchstateSverker Eriksson
Conflicts: erts/emulator/beam/erl_printf_term.c erts/emulator/beam/erl_term.c erts/emulator/beam/utils.c
2015-09-01erts: Fix bug when tracing with 'process_dump'Sverker Eriksson
If the process stack contained a match state the print function would crash the vm as it was not recognized by tag_val_def(). Add new MATCHSTATE_DEF returned by tag_val_def(). All other callers either ignore it or has a default clause to handle invalid terms.
2015-07-01erts: Remove halfword !HEAP_ON_C_STACKBjörn-Egil Dahlberg
2015-06-18Change license text to APLv2Bruce Yinhe
2014-01-28erts: Initial Map instructions, type and structureBjörn-Egil Dahlberg
2013-11-18trapping binary_to_term passing binary_SUITESverker Eriksson
2013-11-18Functionality for disabling garbage collectionRickard Green
Being able to disable garbage collection over context switches vastly simplifies implementation of yielding native code that builds large or complex data structures on the heap. This since the heap can be left in an inconsistent state over the context switch.
2012-12-07Merge branch 'rickard/port-optimizations/OTP-10336' into ↵Rickard Green
rickard/r16/port-optimizations/OTP-10336 * rickard/port-optimizations/OTP-10336: Change annotate level for emacs-22 in cerl Update etp-commands Add documentation on communication in Erlang Add support for busy port message queue Add driver callback epilogue Implement true asynchronous signaling between processes and ports Add erl_drv_[send|output]_term Move busy port flag Use rwlock for driver list Optimize management of port tasks Improve configuration of process and port tables Remove R9 compatibility features Use ptab functionality also for ports Prepare for use of ptab functionality also for ports Atomic port state Generalize process table implementation Implement functionality for delaying thread progress from unmanaged threads Conflicts: erts/doc/src/erl_driver.xml erts/doc/src/erlang.xml erts/emulator/beam/beam_bif_load.c erts/emulator/beam/beam_bp.c erts/emulator/beam/beam_emu.c erts/emulator/beam/bif.c erts/emulator/beam/copy.c erts/emulator/beam/erl_alloc.c erts/emulator/beam/erl_alloc.types erts/emulator/beam/erl_bif_info.c erts/emulator/beam/erl_bif_port.c erts/emulator/beam/erl_bif_trace.c erts/emulator/beam/erl_init.c erts/emulator/beam/erl_message.c erts/emulator/beam/erl_port_task.c erts/emulator/beam/erl_process.c erts/emulator/beam/erl_process.h erts/emulator/beam/erl_process_lock.c erts/emulator/beam/erl_trace.c erts/emulator/beam/export.h erts/emulator/beam/global.h erts/emulator/beam/io.c erts/emulator/sys/unix/sys.c erts/emulator/sys/vxworks/sys.c erts/emulator/test/port_SUITE.erl erts/etc/unix/cerl.src erts/preloaded/ebin/erlang.beam erts/preloaded/ebin/prim_inet.beam erts/preloaded/src/prim_inet.erl lib/hipe/cerl/erl_bif_types.erl lib/kernel/doc/src/inet.xml lib/kernel/src/inet.erl
2012-12-03Prepare for use of ptab functionality also for portsRickard Green
2012-08-31Update copyright yearsBjörn-Egil Dahlberg
2012-05-10Remove stale code for hybrid heap and incremental GCBjörn Gustavsson
The hybrid heap emulator was last working in the non-SMP R11B run-time system. When the constant pools were introduced in R12B, the hybrid heap emulator was not updated to handle them. At this point, the harm from reduced readability of the code is greater than any potential usefulness of keeping the code.
2010-06-03OTP-8555 Send message from NIFSverker Eriksson
New NIF features: Send messages from a NIF, or from thread created by NIF, to any local process (enif_send) Store terms between NIF calls (enif_alloc_env, enif_make_copy) Create binary terms with user defined memory management (enif_make_resource_binary)
2010-04-30emulator: Remove stray OSE/Delta supportBjörn Gustavsson
2010-03-10Store pointers to heap data in 32-bit wordsPatrik Nyblom
Store Erlang terms in 32-bit entities on the heap, expanding the pointers to 64-bit when needed. This works because all terms are stored on addresses in the 32-bit address range (the 32 most significant bits of pointers to term data are always 0). Introduce a new datatype called UWord (along with its companion SWord), which is an integer having the exact same size as the machine word (a void *), but might be larger than Eterm/Uint. Store code as machine words, as the instructions are pointers to executable code which might reside outside the 32-bit address range. Continuation pointers are stored on the 32-bit stack and hence must point to addresses in the low range, which means that loaded beam code much be placed in the low 32-bit address range (but, as said earlier, the instructions themselves are full words). No Erlang term data can be stored on C stacks (enforced by an earlier commit). This version gives a prompt, but test cases still fail (and dump core). The loader (and emulator loop) has instruction packing disabled. The main issues has been in rewriting loader and actual virtual machine. Subsystems (like distribution) does not work yet.
2010-03-10Fit all heap data into the 32-bit address rangePatrik Nyblom
This is the first step in the implementation of the half-word emulator, a 64-bit emulator where all pointers to heap data will be stored in 32-bit words. Code specific for this emulator variant is conditionally compiled when the HALFWORD_HEAP define has a non-zero value. First force all pointers to heap data to fall into a single 32-bit range, but still store them in 64-bit words. Temporary term data stored on C stack is moved into scheduler specific storage (allocated as heaps) and macros are added to make this happen only in emulators where this is needed. For a vanilla VM the temporary terms are still stored on the C stack.
2010-01-13OTP-8240 Improved GC performance after BIF/NIF call when a lot of heapSverker Eriksson
fragments was created. This will mainly benefit NIFs that return large compound terms.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP