Make os.get_env consistent across Unixes
This matches the function name and API from env_windows.odin and os_linux.odin, which should be the same everywhere. Meaning:
* named get_env and not getenv
* return a string (empty if the environment variable is not found)
* accept a default value parameter for the allocator (defaulting to context.allocator)
* calls lookup_env which returns an extra found boolean value
This is so that you don't have to write platform/OS conditionals when getting environment variable values from the stdlib os.get_env/getenv function.
where clone_to_cstring is used with foreign code, it is prefered to use `context.temp_allocator` instead of using the general allocator and manually delete the memory after use.
The stat struct was the format for the 64 bit version of stat. So we need to call stat64 to get the proper data.
Also we need to use _File_Time instead of File_Time because it is a compound value.
These changes were tested and work on my computer, MacOS 64 bit.
Also do some cleanup and refactoring of the thread, sync and time APIs.
- remove 'semaphore_release' because 'post' and 'wait' is easier to understand
- change 'semaphore_wait' to '*_wait_for' to match Condition
- pthreads can be given a stack, but doing so requires the user to set up the guard
pages manually. BE WARNED. The alignment requirements of the stack are also
platform-dependant; it may need to be page size aligned on some systems.
Unclear which systems, however. See 'os.get_page_size', and 'mem.make_aligned'.
HOWEVER: I was unable to get custom stacks with guard pages working reliably,
so while you can do it, the API does not support it.
- add 'os.get_page_size', 'mem.make_aligned', and 'mem.new_aligned'.
- removed thread return values because windows and linux are not consistent; windows returns 'i32'
and pthreads return 'void*'; besides which, if you really wanted to communicate how the
thread exited, you probably wouldn't do it with the thread's exit code.
- fixed 'thread.is_done' on Windows; it didn't report true immediately after calling 'thread.join'.
- moved time related stuff out of 'core:os' to 'core:time'.
- add 'mem.align_backward'
- fixed default allocator alignment
The heap on Windows, and calloc on Linux, both have no facility to request alignment.
It's a bit of hack, but the heap_allocator now overallocates; `size + alignment` bytes,
and aligns things to at least 2.
It does both of these things to ensure that there is at least two bytes before the payload,
which it uses to store how much padding it needed to insert in order to fulfil the alignment
requested.
- make conditions more sane by matching the Windows behaviour.
The fact that they were signalled now lingers until a thread tries to wait,
causing them to just pass by uninterrupted, without sleeping or locking the
underlying mutex, as it would otherwise need to do.
This means that a thread no longer has to be waiting in order to be signalled, which
avoids timing bugs that causes deadlocks that are hard to debug and fix.
See the comment on the `sync.Condition.flag` field.
- add thread priority: `thread.create(worker_proc, .High)`
William Roe
Vitaly Kravchenko
gingerBill
Sébastien Marie
gingerBill
Jeroen van Rijn
Colin Davidson
Platin21
CiD-
Ricardo Silva
kennethmaples
Platin21
Oskar Nordquist
Hasen Judy
Clay Murray
Tetralux
Chris Heyes