POSIX specifies that the sa_handler field of the sigaction struct may
be set to SIG_IGN or SIG_DFL. However, the current constants in the
standard library use the function pointer signature corresponding to
the sa_sigaction field instead.
This may not cause issues in practice because the fields usually occupy
the same memory in a union, but this isn't required by POSIX and there
may be systems we do not yet support that do this differently.
Fixing this also makes the Zig interface less confusing to use after
reading the man page.
Currently, the new API will only be available on macOS with
the intention of adding more POSIX systems to it incrementally
(such as Linux, etc.).
Changes:
* add `posix_spawn` wrappers in a separate container in
`os/posix_spawn.zig`
* rewrite `ChildProcess.spawnPosix` using `posix_spawn` targeting macOS
as `ChildProcess.spawnMacos`
* introduce a `posix_spawn` specific `std.c.waitpid` wrapper which
does return an error in case the child process failed to exec - this
is required for any process that was spawned using `posix_spawn`
mechanism as, by definition, the errors returned by `posix_spawn`
routine cover only the `fork`-equivalent; `pre-exec()` and `exec()`
steps are covered by a catch-all error `ECHILD` returned by `waitpid`
on unsuccessful execution, e.g., no such file error, etc.
Adds the `tcflag_t` type to the termios constants.
This is made to allow bitwise operations on the termios
constants without an integer cast, e.g.:
```zig
var raw = try std.os.tcgetattr(std.os.STDIN_FILENO);
raw.lflag &= std.os.linux.ECHO | std.os.linux.ICANON;
```
instead of
```zig
var raw = try std.os.tcgetattr(std.os.STDIN_FILENO);
raw.lflag &= ~@intCast(u32, std.os.linux.ECHO | std.os.linux.ICANON);
```
Contributes to #10181
Some systems (Solaris, OpenBSD, AIX) change their definitions of
sockaddr_storage to be larger than 128 bytes. This comment adds a new
constant in the `sockaddr` that defines the size for every system.
Fixes#9759
* std lib tests are passing on x86_64-linux with and without -lc
* stage2 is building from source on x86_64-linux
* down to 38 remaining uses of `usingnamespace`
The main purpose of this branch is to explore avoiding the
`usingnamespace` feature of the zig language, specifically with regards
to `std.os` and related functionality.
If this experiment is successful, it will provide a data point on
whether or not it would be practical to entirely remove `usingnamespace`
from the language.
In this commit, `usingnamespace` has been completely eliminated from
the Linux x86_64 compilation path, aside from io_uring.
The behavior tests pass, however that's as far as this branch goes. It is
very breaking, and a lot more work is needed before it could be
considered mergeable. I wanted to put a pull requset up early so that
zig programmers have time to provide feedback.
This is progress towards closing #6600 since it clarifies where the
actual "owner" of each declaration is, and reduces the number of
different ways to import the same declarations.
One of the main organizational strategies used here is to do namespacing
with real namespaces (e.g. structs) rather than by having declarations
share a common prefix (the C strategy). It's no coincidence that
`usingnamespace` has similar semantics to `#include` and becomes much
less necessary when using proper namespaces.
We already have a LICENSE file that covers the Zig Standard Library. We
no longer need to remind everyone that the license is MIT in every single
file.
Previously this was introduced to clarify the situation for a fork of
Zig that made Zig's LICENSE file harder to find, and replaced it with
their own license that required annual payments to their company.
However that fork now appears to be dead. So there is no need to
reinforce the copyright notice in every single file.
The primary purpose of this change is to eliminate one usage of
`usingnamespace` in the standard library - specifically the usage for
errno values in `std.os.linux`.
This is accomplished by truncating the `E` prefix from error values, and
making errno a proper enum.
A similar strategy can be used to eliminate some other `usingnamespace`
sites in the std lib.
* move concurrency primitives that always operate on kernel threads to
the std.Thread namespace
* remove std.SpinLock. Nobody should use this in a non-freestanding
environment; the other primitives are always preferable. In
freestanding, it will be necessary to put custom spin logic in there,
so there are no use cases for a std lib version.
* move some std lib files to the top level fields convention
* add std.Thread.spinLoopHint
* add std.Thread.Condition
* add std.Thread.Semaphore
* new implementation of std.Thread.Mutex for Windows and non-pthreads Linux
* add std.Thread.RwLock
Implementations provided by @kprotty
* split std.ResetEvent into:
- ResetEvent - requires init() at runtime and it can fail. Also
requires deinit().
- StaticResetEvent - can be statically initialized and requires no
deinitialization. Initialization cannot fail.
* the POSIX sem_t implementation can in fact fail on initialization
because it is allowed to be implemented as a file descriptor.
* Completely define, clarify, and explain in detail the semantics of
these APIs. Remove the `isSet` function.
* `ResetEvent.timedWait` returns an enum instead of a possible error.
* `ResetEvent.init` takes a pointer to the ResetEvent instead of
returning a copy.
* On Darwin, `ResetEvent` is implemented using Grand Central Dispatch,
which is exposed by libSystem.
stage2 changes:
* ThreadPool: use a single, pre-initialized `ResetEvent` per worker.
* WaitGroup: now requires init() and deinit() and init() can fail.
- Add a `reset` function.
- Compilation initializes one for the work queue in creation and
re-uses it for every update.
- Rename `stop` to `finish`.
- Simplify the implementation based on the usage pattern.
Do the alignment dance by ourselves whenever posix_memalign is not
available.
Don't try to use malloc as it has too many edge cases, figuring out
whether a block of memory is manually aligned by the mechanism above or
is directly coming from malloc becomes too hard to be valuable.
