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author | Rickard Green <[email protected]> | 2018-03-07 01:17:21 +0100 |
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committer | Rickard Green <[email protected]> | 2018-03-21 10:27:03 +0100 |
commit | 4bc282d812cc2c49aa3e2d073e96c720f16aa270 (patch) | |
tree | a7b00cd079368590dc09f62a4d5402be157462ca /erts/emulator/beam/erl_alloc.types | |
parent | 348a4e057db36fac13f1551c0a1c17f0d376da48 (diff) | |
download | otp-4bc282d812cc2c49aa3e2d073e96c720f16aa270.tar.gz otp-4bc282d812cc2c49aa3e2d073e96c720f16aa270.tar.bz2 otp-4bc282d812cc2c49aa3e2d073e96c720f16aa270.zip |
Implementation of true asynchronous signaling between processes
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The previously used message queue partitioned into two halves has been
replaced by a more general signal queue partitioned into three parts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.
Diffstat (limited to 'erts/emulator/beam/erl_alloc.types')
-rw-r--r-- | erts/emulator/beam/erl_alloc.types | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types index 8107f133aa..4a6a19b210 100644 --- a/erts/emulator/beam/erl_alloc.types +++ b/erts/emulator/beam/erl_alloc.types @@ -1,7 +1,7 @@ # # %CopyrightBegin% # -# Copyright Ericsson AB 2003-2017. All Rights Reserved. +# Copyright Ericsson AB 2003-2018. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -282,6 +282,11 @@ type THR_PRGR_IDATA LONG_LIVED SYSTEM thr_prgr_internal_data type THR_PRGR_DATA LONG_LIVED SYSTEM thr_prgr_data type T_THR_PRGR_DATA SHORT_LIVED SYSTEM temp_thr_prgr_data type RELEASE_LAREA SHORT_LIVED SYSTEM release_literal_area +type SIG_DATA SHORT_LIVED PROCESSES signal_data +type DIST_DEMONITOR SHORT_LIVED PROCESSES dist_demonitor +type CML_CLEANUP SHORT_LIVED SYSTEM connection_ml_cleanup +type ML_YIELD_STATE SHORT_LIVED SYSTEM monitor_link_yield_state +type ML_DIST STANDARD SYSTEM monitor_link_dist type ENVIRONMENT SYSTEM SYSTEM environment @@ -326,8 +331,8 @@ type LCNT_VECTOR SHORT_LIVED SYSTEM lcnt_sample_vector type DEBUG SHORT_LIVED SYSTEM debugging type DDLL_PROCESS STANDARD SYSTEM ddll_processes -type MONITOR_LH STANDARD PROCESSES monitor_lh -type NLINK_LH STANDARD PROCESSES nlink_lh +type MONITOR_EXT STANDARD PROCESSES monitor_extended +type LINK_EXT STANDARD PROCESSES link_extended type CODE LONG_LIVED CODE code type LITERAL LITERAL CODE literal type LITERAL_REF SHORT_LIVED CODE literal_area_ref @@ -340,8 +345,8 @@ type LL_TEMP_TERM LONG_LIVED SYSTEM ll_temp_term type NIF_TRAP_EXPORT STANDARD PROCESSES nif_trap_export_entry type NIF_EXP_TRACE FIXED_SIZE PROCESSES nif_export_trace type EXPORT LONG_LIVED CODE export_entry -type MONITOR_SH FIXED_SIZE PROCESSES monitor_sh -type NLINK_SH FIXED_SIZE PROCESSES nlink_sh +type MONITOR FIXED_SIZE PROCESSES monitor +type LINK FIXED_SIZE PROCESSES link type AINFO_REQ SHORT_LIVED SYSTEM alloc_info_request type SCHED_WTIME_REQ SHORT_LIVED SYSTEM sched_wall_time_request type GC_INFO_REQ SHORT_LIVED SYSTEM gc_info_request |