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).
Introduce caml_process_pending_actions and
caml_process_pending_actions_exn: a variant of the former which does
not raise but returns a value that has to be checked against
Is_exception_value.
I keep the current conventions from caml_callback{,_exn}: For a
resource-safe interface, we mostly care about the _exn variants, but
every time there is a public _exn function I provide a function that
raises directly for convenience.
They are introduced and documented in caml/signals.h.
Private functions are converted to their _exn variant on the way as
needed: for internal functions of the runtime, it is desirable to go
towards a complete elimination of functions that raise implicitly.
Get rid of the distant logic of caml_raise_in_async_callback. Instead,
caml_process_pending_events takes care itself of its something_to_do
"resource". This avoids calling the former function in places
unrelated to asynchronous callbacks.
caml_minor_collection is not a new function, it is already used in the
wild and used to be exposed in caml/minor_gc.h in the past. The change
simply amounts to replacing a call to caml_request_minor_gc() with an
assignment requested_minor_gc = 1, bypassing
caml_set_something_to_do().
In 8691, caml_check_urgent_gc was merged with the function that runs
asynchronous callbacks. The rationale was that caml_check_urgent_gc
already runs finalisers, and so could have run any asynchronous
callbacks.
We agreed on a different strategy: we know that users could not rely
on asynchronous callbacks being called at this point, so take the
opportunity to make it callback-safe, like was done for allocation
functions.
The new check_urgent_gc no longer calls finalisers (nor any
callbacks), and instead two internal functions are introduced:
* caml_do_urgent_gc_and_callbacks : function to perform actions
unconditionally.
* caml_check_urgent_gc_and_callbacks : function that checks for
something to do, and then executes all actions (GC and callbacks).
When configured with -no-flat-float-array, the primitive caml_make_float_vect
(known as Array.create_float in OCaml) is completely broken:
1. it fails to raise Invalid_argument when the size is negative or too large.
2. it fails to initialize its result, which immediately leads to segfault.
Nicolás Ojeda Bär
Enguerrand Decorne
Guillaume Munch-Maccagnoni
KC Sivaramakrishnan
Alain Frisch
Jacques-Henri Jourdan
Damien Doligez
Sébastien Hinderer