Disable incremental promotion when backreferences are enabled,
otherwise the backreference list for a generation can have
references to younger-generation objects.
Casting a ptr to an integer of a different size causes a warning - this is only noticeable on 32bits. Fix this by using `TO_VOIDP` and `TO_PTR` helper macros.
This PR fixes two issues regarding disappeared-use in reqprov.rkt
1. Copy/preserve disappeared-use for all provide subforms instead
of only the first one. The following program doesn't have an arrow from
`struct-out` to `#lang racket` prior this PR, but it does after this PR.
#lang racket
(provide a? (struct-out a))
(struct a ())
2. Fix incorrect `disappeared-use` for `struct-out`: it is inappropriate
to check if an identifier is bound to a struct info in provide
pre-transformer because it would not be able to handle backlinks.
This PR moves the attachment from provide pre-transformer to provide
transformer, allowing Check Syntax to draw an arrow for the identifier
`abc` in:
#lang racket
(provide (struct-out abc))
(struct abc ())
<tt> is a "non-conforming feature".
It is "entirely obsolete, and must not be used by authors"
as specified in https://www.w3.org/TR/html51/obsolete.html#elementdef-tt.
This PR replaces <tt> with either <code> or <kbd> as suggested
in the above recommendation. Practically, it improves accessibility
of the page, allowing screen readers to understand the document
more accurately.
Note that both <code> and <kbd> are recognized in older browsers already,
so this PR doesn't cause any incompatibility issue.
When focusing on a preference option, the status line
is supposed to change to the the preference's description.
However, because the variable that stores descriptions
is declared in a wrong scope, it results in an unbound id error
and nothing changes. This PR fixes the problem.
Small fixes to enable LTO compilation
To do this in racket/src:
./configure CFLAGS="-O3 -march=native -flto"
LDFLAGS="-O3 -march=native -flto"
--prefix=...
One fix deals with variable `errnum` that might be used uninitialized.
The other is to ensure that `boot_file_data` is marked as used
otherwise, it is removed by LTO and ends up crashing build
in `embed-boot.rkt`.
Instead of having leftover Scheme threads swept by the main thread,
distribute Scheme threads among sweeper threads, and swap into each
thread's content to preserve its allocation ownership. This change
makes parallelism more consistent for different timings that end up
assigning sweepers differently.
Move per-thread allocation information to a separate object, so the
needs of the collector are better separated from the thread
representation. This refactoring sets up a change in the collector to
detangle sweeper threads from Scheme threads.
Change the internal parallelism strategy for the GC to record an owner
for each allocated segment of memory, and have the owner be solely
responsible for copying or marking objects of the segment. When
sweeping, a collecting thread handles references to objects that it
owns or that have been copied or marked already, and it asks another
collecting thread to resweep an object that refers to objects owned by
that that thread. At worst, an object ends up being swept by all
collecting threads, one at a time, but that's unlikely for a given
object.
The approach seems likely to scale better than a lock-based approach,
even the one that used a lightweight, CAS-based lock and retries on
lock failure.
That is, use pairs on the property in more places, as the pair
already was computed and the value-blame function already does
the needful when it sees a pair on the property.
When the GC needs to copy/mark a record, it previously forced a
copy/mark on the record's type descriptor, since the copy/mark needs
information from the descriptor. But the needed information is not in
danger of being overwritten for forwading (since it's after the first
two words of the type descriptor), so it's ok to use the old reference
as-is --- at least in non-counting mode. Simplifying record-type
handling and deferring the record-type update to the sweep phase, the
same as for other components of the record type, makes the GC slightly
faster.
