The use of a will executor for a custodian is a bit of a hack, and it
doesn't want the "keep live until executed" constraint. So, add an
optional internally.
If a late will executor has pending will, then it needs to stay
live until the enclosing place has terminated (and post-custodian
callbacks are run). Otherwise, `ffi/unsafe/alloc` can lose values
that it expects to finalize, and it reports an "internal error".
The late will executor for `register-finalizer` from `ffi/unsafe`
was kept live in traditional Racket, but only as an accident of
custodian shutdown in a terminating place: the shutdown process skips
threads, since that work is technically not necessary. Relying on that
coincidence is asking for trouble, though, so implement retention more
deliberately.
Recognize `(ptr-ref <ptr> _uint8)`, etc., and turn it into a more
direct `(ptr-ref/uint8 <ptr>)`, etc. This improvement speeds PNG
loading by a factor of 10 to 20, for example, because the
implementation expects the pattern to be recognized.
When the number of places approaches the number of available
processing cores, then a spin lock isn't good enough for a small
number of contended hash tables (maybe just one of them). When
contention is discovered, fall back to a mutex-based lock.
When spawning a new subprocess, it's possible that one or more of the
new process's standard input, output, or error descriptors use file
descriptor 0, 1, or 2, even if they don't correspond to any of the
parent process's original standard input, output, or error descriptors.
This can happen if the parent process closes one of its standard
descriptors, and the operating system reuses the file descriptor number
for a new descriptor.
Therefore, be more careful about closing and copying file descriptors in
the child process before calling `exec`. Specifically, move file
descriptors out of the way as needed so they aren't clobbered, and
accommodate cases where multiple standard streams may share the same
file descriptor in the parent process.
fixes#2634
A subcustodian was incorrectly registered as weak for its parent,
which means that an unreferenced custodian could get lost when
shutting down an ancestor.
Register the port, not the file descriptor, especially since a TCP
connection can have ports that share a file descriptor. Also, I think
a weak reference in the custodian doesn't work as intended (visible
through finalization) if the file descriptor is referenced with a
callback that closes over the port.
No `syntax-protect` is needed for `define/private`, etc., because no
new identifiers or expressions are introduced. Adding extra dye packs
can interfere with other macros that pull apart syntax (although maybe
the macros shouldn't do that without using `syntax-disarm`).
A custodian doesn't provide any order on shutting down the objects
that it manages (I was confused about some past experiments), so
avoid that assumption.
Getting the current CPU time is relatively expensive, so get it only
on thread swaps where a thread used its full quantum or 1/100 swaps
otherwise. This approximation should work because thread-specific CPU
times are rarely requested, and they make the most sense for threads
that don't constantly swap out due to synchronization.
Formerly, an expression like `(arity-at-least-value 7)` could crash,
because the `arity-at-least-value` accessor is created in unsafe mode,
and the slow path to accessor errors attempted to use the accessor to
provoke an error message. Instead of using a potentially unsafe
accessor, have the slow path raise an error explicitly with
`raise-argument-arror`. That change has the added benefit of making
error messages mach traditional Racket (at least for structure types
that are not declared as "authentic").
The problem was exposed by tests added in 55dcdf5538.
Instead of a separate hash table mapping continuations to
linklet-instance names, use a continuation mark. That's faster,
because capturing a continuation means copying part of it on continue.
Currently, Check Syntax has trouble correlating `require` forms and
references to imports that go through a macro-introduced rename
transformer. For example, there's no binding arrow from the final
`starting` to the `racket/list` in
#lang racket/base
(require (for-syntax racket/base))
(define-syntax-rule (define-as-first mod starting)
(begin
(require (only-in mod
[first initial]))
(define-syntax starting (make-rename-transformer #'initial))
starting))
(define-as-first racket/list starting)
starting
But change the last two `starting`s to `initial`, and the binding
arrows work.
Until a general repair is in place for Check Syntax, this commit
adjusts 38d612dba6 to use the original export name for an immediate
binding, which acts as a hint to the current Check Syntax
implemenration.
Note that the source-distribution client must have a
"build/ChezScheme" checkout created, maybe by building as a 'cs
variant. A pruned version of that checkout is then included with other
sources. The resulting source distributon then works for building
either Racket variant.
Adapt the configure scripts and makefiles to use a "ChezScheme"
directory that is bundled with sources.
Some expressions like (date-day) gave usually an arity error, but when they
were inlined by the JIT the arity check was wrong, so they produce a segfault
or a nonsensical result.
Provide a way to build Chez Scheme from source using Racket. In the
short run, this lets us distribute source that ultimately depends only
on a C compiler (since a variant of Racket can be built from source
using just a C compiler).
- change an 'an' to 'a'
- remove 'immutable' where expecting either mutable or immutable (don't
bother to specify which, because `vector-common.rkt` doesn't bother)
- remove extra ','
The `poll` system call doesn't work right for fifos, so switch
back to `select`, but use a new strategy to size fd_set buffers
instead of trying to use `getdtablesize` (because the result
of `getdtablesize` can change dynamically on Mac OS).
Also, add a check for input at the rktio level when trying to read
from devices other than regular files. Otherwise, Racket CS (which
doesn't have some redundant polling that is in traditional Racket)
sees spurious EOFs for unconnected fifos.
Closes#2577
* Remove value store in ready_pos but unread
* Move declaration of ready_pos to where it is used
* Make discard of return value of tcp_check_accept explicit
* Split declaration and var assignment to comply with xform
Making `equal?` do the right thing on classes turned out to be easy---it
just involved adding a straightforward `prop:equal+hash` property to the
`class` struct—but making it work properly for *objects* was the tricky
part. The trouble is that `equal?` on objects that don’t implement the
`equal<%>` interface is just ordinary structure equality, which can be
relevant if objects are inspectable. Writing `(inspect #f)` in a class
body is like making a struct `#:transparent`, and it has all the same
ramifications for equality.
The trouble is that `class/c` creates new wrapper classes, and every
class has its own struct type. Since the default behavior of `equal?` on
structs is to *never* be equal to structs of different types, even
subtypes, an object created from a contracted class can never be
`equal?` to an object created from the same class without contracts.
The solution is to add a `prop:equal+hash` property to `object%` itself
that emulates the default behavior of `equal?`, but sees through class
contract wrappers. Since struct type properties are inherited by
subtypes, this property will be present on all objects, and it only
needs to be attached once.
fixes#2279
Mainly, this improves `make-keyword-procedure`: when applied to a single
argument, it now uses `procedure-rename` to ensure the resulting
procedure has the appropriate name. A couple other changes also guard
against the case where a lambda expression has no inferred name and no
source locations information, which would lead to the source locations
in the implementation being used, instead.
