Introduce type Obj.raw_data and functions Obj.raw_field, Obj.set_raw_field to manipulate out-of-heap pointers in no-naked-pointers mode, and more generally all other data that is not a well-formed OCaml value
Some OCaml objects contain data that cannot be safely represented
as an OCaml value (type Obj.t). For example, in no-naked-pointers mode,
this is the case for code pointers inside closures, and for the
"custom operations" pointers inside custom blocks.
This PR introduces a type Obj.raw_data (an alias for nativeint)
to encapsulate this data, and functions
Obj.raw_field / Obj.set_raw_field to read and write the "raw" contents
of fields of blocks.
Note: just like it is wrong to access code pointers and custom operations
using Obj.field / Obj.set_field, it is wrong to access regular fields
possibly containing pointers into the OCaml heap using
Obj.raw_field / Obj.set_raw_field. The OCaml heap block can be
reclaimed or moved after its address was captured by Obj.raw_field.
Symmetrically, Obj.set_raw_field on a regular field bypasses the
write barrier of the GC.
This module provides a purely sequential implementation of the
concurrent atomic references provided by the Multicore OCaml
standard library:
https://github.com/ocaml-multicore/ocaml-multicore/blob/parallel_minor_gc/stdlib/atomic.mli
This sequential implementation is provided in the interest of
compatibility: when people will start writing code to run on
Multicore, it would be nice if their use of Atomic was
backward-compatible with older versions of OCaml without having to
import additional compatibility layers. *)
- Add the key argument in the description of 'merge'
- Note that the keys of 'union f m1 m2' are a subset of the
input keys, not all the keys, since
bindings (union (fun _ _ _ -> None) m m) = []
- Fix grammar in the descriptions of 'filter', 'union', 'merge'
- Fix mismatched variable name in the description of 'partition'
- Note that 'find' and 'find_opt' return values, not bindings
The instrumentation code in the instrumented runtime was replaced
with new APIs to gather runtime statistics and output them in a new format
(Common Trace Format).
This commit also exposes new functions in the Gc module to pause or resume
instrumentation during a program execution (Gc.eventlog_pause and
Gc.eventlog_resume).
The docs on this are out of date: they say runtime warnings are enabled by
default, but the source code has a commit 6c90da4 pointing to
https://github.com/ocaml/ocaml/pull/210 that disables them by default.
It seems like enabling runtime warnings by default never made its way into a
release and the docs could just be updated to say that runtime warnings are
disabled by default.
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
This moves the configure-generated parts of Makefile.common to a
separate (generated) Makefile, allowing Makefile.common to be a normal
Makefile.
OCaml's build system Makefile's now include Makefile.build_config (which
itself includes Makefile.config) but Makefile.config is still installed
as before. This allows configure to generate variables which are
specific to the build process and are not intended to be exported to the
installation.
The Gc.Memprof module provides a low-level API, that will hopefully be
paired with user libraries that provide high-level instrumentation
choices.
A natural question is: how are the higher-level API going to expose
their choice of instrumentation to their users? With the current
Memprof.start API (before this patch), they would have to either
provide their own `start` function wrapping Memprof.start, or provide
a tuple of callbacks for to their users to pass to Memprof.start
themselves.
val start : params -> unit
(* or *)
val callback : params ->
((allocation -> foo option) * (allocation -> bar option) * ... )
With an explicit record, it is easier for libraries to expose an
instrumentation choice (possibility parametrized over
user-provided settings):
val tracker : params -> (foo, bar) Gc.Memprof.tracker
In addition, providing a record instead of optional parameters makes
it much easier to provide "default settings" (helper functions) that
instantiates the types `'minor` and `'ḿajor`, see for example
`simple_tracker` in this patch (which stores the same information for
the minor and major heap, and does not observe promotion), or to later
define checking predicates that can verify that a given choice of
callbacks is sensible (for example: providing a major-dealloc callback
but no promotion callback (dropping all tracked value on promotion) is
probably not a good idea).
Bootstrap: to avoid requiring an awkward bootstrap, this commit keeps
the (now unused) function caml_memprof_start_byt unchanged -- it is
used in the bootstrap binaries, so removing it would break the
build. The intention is to remove it in the following commit.
Printexc.uncaught_exception_handler ceases to be an option ref and becomes
a ref to the handler function initialized to
Printexc.default_uncaught_exception_handler.
Xavier Leroy
Gabriel Scherer
Sébastien Hinderer
Xavier Leroy
Guillaume Munch-Maccagnoni
octachron
Sébastien Briais
Nicolás Ojeda Bär
Christophe Troestler
Florian Angeletti
Josh Berdine
Josh Berdine
Jeremy Yallop
Enguerrand Decorne
Edwin Török
Stephen Dolan
Mark Shinwell
Greta Yorsh
David Allsopp
muskangarg21
zapashcanon
Glenn Slotte
Raphael Sousa Santos