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* 'map-get-bif' of git://github.com/michalmuskala/otp:
Introduce map_get guard-safe function
OTP-15037
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Improve memory instrumentation
OTP-15024
OTP-14961
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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.
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fix integer truncation bugs in error logger path
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* sverker/valgrind-uninit-run_queue-ptr:
erts: Fix run queue pointer in proxy process
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* sverker/ets-cherries/OTP-15031:
erts: Use table ref for select continuation
erts: Refactor erl_db_hash next() into next_live()
erts: Change wrong alloc_fnf
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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).
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* lukas/erts/seq_tracer_nif/OTP-15029:
Fix seq_trace erl_tracer bug
Fix makefile mkdir warning
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Sending a large term to the error logger has two problems related
to the size and sign of the variables used to represent lengths:
- the API functions (erts_send_error_term_to_logger() et al) perform
an unchecked narrowing conversion from size_t to int when passing
dsbufp->str_len to the internal functions; this may both truncate
the length and make it negative
- do_send_term_to_logger() and do_send_to_logger() multiply the
int-typed length by 2 before widening it to Uint and adding a few
more values; the intermediate product may overflow causing loss
of high bits and a change of sign; if the intermediate product is
negative the final size will be an extremely large positive value
The end result is that the computed buffer size can be arbitrarily
wrong, either too small or too large.
While reviewing this code I also found and fixed a potential narrowing
bug in erts_set_hole_marker().
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and not the name. For more sane named table semantics.
Applies to both select/1 continuation and trap context.
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where argument 'list' is the first candidate (not list->next).
Also simplified db_first_hash().
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There is no NULL check here !?
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proc->run_queue detected as uninitialized by valgrind
but seems harmless in practice as it's not used for proxy processes.
"Bug" introduced in OTP-17 by ca0425c6ff85262bc15367f5fd9cbc51cde52b20
and made worse (but still harmless) in master for OTP-21
at fbb10ebc4a37555c7ea7f99e14286d862993976a.
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It is allowed to set the backtrace depth to 0, but when
an exception is catched the stacktrace will still contain
one element:
1> erlang:system_flag(backtrace_depth, 0).
8
2> catch error(badarg).
{'EXIT',{badarg,[{shell,apply_fun,3,
[{file,"shell.erl"},{line,908}]}]}}
However, when an exception is raised using `erlang:raise/3`, there
will be no elements in the stacktrace:
3> catch erlang:raise(error, badarg, [{fake,name,[arg],[]}]).
{'EXIT',{badarg,[]}}
Since the `error_handler` module uses `erlang:raise/3` to
raise an exception when an undefined function is called,
there will not be any stacktrace when calling an undefined
function:
4> catch undef_module:undef_name(some_argument).
{'EXIT',{undef,[]}}
Fix this inconsistency by changing `erlang:raise/3` so that
it always includes one element in the stacktrace:
3> catch erlang:raise(error, badarg, [{fake,name,[arg],[]}]).
{'EXIT',{badarg,[{fake,name,[arg],[]}]}}
4> catch undef_module:undef_name(some_argument).
{'EXIT',{undef,[{undef_module,undef_name,[some_argument],[]}]}}
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OTP-15024
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This may be of interest in crash dumps and allows the upcoming
allocation tagging feature to track allocations on a per-NIF basis.
Note that this is only updated when user code calls a NIF; it's not
altered when the emulator calls NIFs during code upgrades or
tracing.
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This increases the accuracy of crash dumps and the upcoming
allocation tagging feature.
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* rickard/process_info/OTP-14966:
Fix deadlock in HiPE gc after receive
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Also removed unused ERTS_LC_STATIC_ALLOC.
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Run debug VM or config with --enable-lock-checking.
Exercise VM and then run
erts_debug:lc_graph().
to create a file "lc_graph.<pid>" in current working directory.
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with just lots of renaming, nothing else.
erts_lc_locked_locks_t -> lc_thread_t
create_locked_locks -> create_thread_data
l_lcks -> thr
l_lck -> ll
And dropped erts_ prefix on some file scope types.
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* rickard/monotonic_time_1_fix/OTP-15008:
Teach erlang:monotonic_time/1 the perf_counter time unit
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* rickard/process_info/OTP-14966:
New process_info() implementation using signals
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* rickard/signals/OTP-14589:
Fix VM probes compilation
Conflicts:
erts/emulator/beam/erl_message.c
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* rickard/signals/OTP-14589:
Fix seq trace
Fix bad assert
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63e1c58d27ab (PR #1725) started to compile external funs
as literals.
This commit updates the dumping of literal areas to dump
external fun literals to the crash dump.
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Compile external fun expressions to literals
OTP-15003
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* sverker/driver-taints/OTP-14960:
erts: Include foreign static linked drivers in taints
erts: Fix harmless bug in macro IS_DRIVER_VERSION_GE
erts: Remove our own NIF modules from "taints"
erts: Refactor erts_static_nif_get_nif_init
erts: Add dynamic loaded drivers to list of "taints"
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* john/erts/bwt-wt-dirty-schedulers/OTP-14959:
Add +sbwt/+swt analogues for dirty schedulers
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jhogberg/john/erts/any-term-as-seq_trace-label/OTP-14899
Lift the type restrictions on seq_trace token labels
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That is, driver added with config option --enable-static-drivers.
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harmless until we bump major version
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The expressions fun M:F/A, when all elements are literals are also
treated as a literal. Since they have consistent representation and
don't depend on the code currently loaded in the VM, this is safe.
This can provide significant performance improvements in code using such
functions extensively - a full function call to erlang:make_fun/3 is
replaced by a single move instruction and no register shuffling or
saving registers to stack is necessary. Additionally, compound data
types that contain such external functions as elements can be treated as
literals too.
The commit also changes the representation of external funs to be a
valid Erlang syntax and adds support for literal external funs to core
Erlang.
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* rickard/signals/OTP-14589:
Fix VM probes compilation
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* raimo/type-posix-0-overhaul/ERL_550/OTP-14019:
Update types for posix error codes
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Sharing these settings for all schedulers can degrade performance,
so it makes sense to be able to configure them separately.
This also changes the default busy-wait time to "short" for both
kinds of dirty schedulers.
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I have read the man pages for most socket and file operations
on recent Linux, FreeBSD, OpenBSD and Solaris 10 and noted
the possible error codes.
Which error codes that are possible for file operations have
been updated in file:posix/0. Error codes for socket operations
in inet:posix/0. The latter refers to the former so it is
a superset, assuming that e.g sendfile and AF_UNIX socket
operations could cause socket operations to return any file
error code. That is not entirely true, but could be,
especially in the future.
Added to file:posix/0 are:
ebadmsg edeadlk edeadlock eftype emultihop enobufs enolck enolink
enosr enostr enosys eopnotsupp eoverflow erange etxtbsy
Added to inet:posix/0 are all but:
exbadport exbadseq file:posix()
These are still possible according to erl_posix_str.c,
but are not in file:posix/0 nor in inet:posix/0,
and many of them are not file nor inet related, but some might be:
e2big eadv ealign ebade ebadfd ebadr ebadrpc ebadrqc
ebadslt ebfont echild echrng ecomm edirty
edom edotdot eduppkg eidrm einit eisnam
elbin el2hlt el2nsync el3hlt el3rst
elibacc elibbad elibexec elibmax elibscn elnrng
enavail enet enoano enocsi enodata enoexec
enonet enosym enotempty enotnam enotuniq
eproclim eprocunavail eprogmismatch eprogunavail
erefused eremchg eremdev eremote eremoteio
eremoterelease erpcmismatch erremote eshutdown
esrmnt esuccesss etime etoomanyrefs
euclean eunatch eusers eversion exfull
sysnotready vernotsupported ediscon enomore
ecancelled einvalidproctable einvalidprovider eproviderfailedinit
syscallfailure service_not_found type_not_found e_no_more
e_cancelled unknown
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* rickard/signals/OTP-14589:
Fix VM probes compilation
Fix lock counting
Fix signal order for is_process_alive
Fix signal handling priority elevation
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