Before, allocator implementations had to provide `allocFn`,
`reallocFn`, and `freeFn`.
Now, they must provide only `reallocFn` and `shrinkFn`.
Reallocating from a zero length slice is allocation, and
shrinking to a zero length slice is freeing.
When the new memory size is less than or equal to the
previous allocation size, `reallocFn` now has the option
to return `error.OutOfMemory` to indicate that the allocator
would not be able to take advantage of the new size.
For more details see #1306. This commit closes#1306.
This commit paves the way to solving #2009.
This commit also introduces a memory leak to all coroutines.
There is an issue where a coroutine calls the function and it
frees its own stack frame, but then the return value of `shrinkFn`
is a slice, which is implemented as an sret struct. Writing to
the return pointer causes invalid memory write. We could work
around it by having a global helper function which has a void
return type and calling that instead. But instead this hack will
suffice until I rework coroutines to be non-allocating. Basically
coroutines are not supported right now until they are reworked as
in #1194.
Mostly picking the same paths as FreeBSD.
We need a little special handling for crt files, as netbsd uses its
own (and not GCC's) for those, with slightly different names.
Previously, std.debug.assert would `@panic` in test builds,
if the assertion failed. Now, it's always `unreachable`.
This makes release mode test builds more accurately test
the actual code that will be run.
However this requires tests to call `std.testing.expect`
rather than `std.debug.assert` to make sure output is correct.
Here is the explanation of when to use either one, copied from
the assert doc comments:
Inside a test block, it is best to use the `std.testing` module
rather than assert, because assert may not detect a test failure
in ReleaseFast and ReleaseSafe mode. Outside of a test block, assert
is the correct function to use.
closes#1304
`std.mem.Allocator.createOne` is renamed to `std.mem.Allocator.create`.
The problem with the previous API is that even after copy elision,
the initalization value passed as a parameter would always be a copy.
With the new API, once copy elision is done, initialization
functions can directly initialize allocated memory in place.
Related:
* #1872
* #1873
* add `@bswap` builtin function. See #767
* comptime evaluation facilities are improved to be able to
handle a `@ptrCast` with a backing array.
* `@truncate` allows "truncating" a u0 value to any integer
type, and the result is always comptime known to be `0`.
* when specifying pointer alignment in a type expression,
the alignment value of pointers which do not have addresses
at runtime is ignored, and always has the default/ABI alignment
* threw in a fix to freebsd/x86_64.zig to update syntax from
language changes
* some improvements are pending #863closes#638closes#1733
std lib API changes
* io.InStream().readIntNe renamed to readIntNative
* io.InStream().readIntLe renamed to readIntLittle
* io.InStream().readIntBe renamed to readIntBig
* introduced io.InStream().readIntForeign
* io.InStream().readInt has parameter order changed
* io.InStream().readVarInt has parameter order changed
* io.InStream().writeIntNe renamed to writeIntNative
* introduced io.InStream().writeIntForeign
* io.InStream().writeIntLe renamed to writeIntLittle
* io.InStream().writeIntBe renamed to writeIntBig
* io.InStream().writeInt has parameter order changed
* mem.readInt has different parameters and semantics
* introduced mem.readIntNative
* introduced mem.readIntForeign
* mem.readIntBE renamed to mem.readIntBig and different API
* mem.readIntLE renamed to mem.readIntLittle and different API
* introduced mem.readIntSliceNative
* introduced mem.readIntSliceForeign
* introduced mem.readIntSliceLittle
* introduced mem.readIntSliceBig
* introduced mem.readIntSlice
* mem.writeInt has different parameters and semantics
* introduced mem.writeIntNative
* introduced mem.writeIntForeign
* mem.writeIntBE renamed to mem.readIntBig and different semantics
* mem.writeIntLE renamed to mem.readIntLittle and different semantics
* introduced mem.writeIntSliceForeign
* introduced mem.writeIntSliceNative
* introduced mem.writeIntSliceBig
* introduced mem.writeIntSliceLittle
* introduced mem.writeIntSlice
* removed mem.endianSwapIfLe
* removed mem.endianSwapIfBe
* removed mem.endianSwapIf
* added mem.littleToNative
* added mem.bigToNative
* added mem.toNative
* added mem.nativeTo
* added mem.nativeToLittle
* added mem.nativeToBig
* Add test to check re-use of memory
* Check if realloc has to reallocate the last allocated memory block.
If so extend that block instead of allocating a new one.
* Also check if the realloc actually preserves the data.
* add std.atomic.QueueMpsc.isEmpty
* make std.debug.global_allocator thread-safe
* std.event.Loop: now you have to choose between
- initSingleThreaded
- initMultiThreaded
* std.event.Loop multiplexes coroutines onto kernel threads
* Remove std.event.Loop.stop. Instead the event loop run() function
returns once there are no pending coroutines.
* fix crash in ir.cpp for calling methods under some conditions
* small progress self-hosted compiler, analyzing top level declarations
* Introduce std.event.Lock for synchronizing coroutines
* introduce std.event.Locked(T) for data that only 1 coroutine should
modify at once.
* make the self hosted compiler use multi threaded event loop
* make std.heap.DirectAllocator thread-safe
See #174
TODO:
* call sched_getaffinity instead of hard coding thread pool size 4
* support for Windows and MacOS
* #1194
* #1197
This is akin to channels in Go, except:
* implemented in userland
* they are lock-free and thread-safe
* they integrate with the userland event loop
The self hosted compiler is changed to use a channel for events,
and made to stay alive, watching files and performing builds when
things change, however the main.zig file exits after 1 build.
Note that nothing is actually built yet, it just parses the input
and then declares that the build succeeded.
Next items to do:
* add windows and macos support for std.event.Loop
* improve the event loop stop() operation
* make the event loop multiplex coroutines onto kernel threads
* watch source file for updates, and provide AST diffs
(at least list the top level declaration changes)
* top level declaration analysis
* enable slicing for single-item ptr to arrays
* disable slicing for other single-item pointers
* enable indexing for single-item ptr to arrays
* disable indexing for other single-item pointers
see #770closes#386
See #770
To help automatically translate code, see the
zig-fmt-pointer-reform-2 branch.
This will convert all & into *. Due to the syntax
ambiguity (which is why we are making this change),
even address-of & will turn into *, so you'll have
to manually fix thes instances. You will be guaranteed
to get compile errors for them - expected 'type', found 'foo'
Use std.heap.FixedBufferAllocator combined with
std.heap.DirectAllocator instead.
std.mem.FixedBufferAllocator is moved to std.heap.FixedBufferAllocator
* DirectAllocator does the underlying syscall for every allocation.
* ArenaAllocator takes another allocator as an argument and
allocates bytes up front, falling back to DirectAllocator with
increasingly large allocation sizes, to avoid calling it too often.
Then the entire arena can be freed at once.
The self hosted parser is updated to take advantage of ArenaAllocator
for the AST that it returns. This significantly reduces the complexity
of cleanup code.
docgen and build runner are updated to use the combination of
ArenaAllocator and DirectAllocator instead of IncrementingAllocator,
which is now deprecated in favor of FixedBufferAllocator combined
with DirectAllocator.
The C allocator calls aligned_alloc instead of malloc, in order to
respect the alignment parameter.
Added asserts in Allocator to ensure that implementors of the
interface return slices of the correct size.
Fixed a bug in Allocator when you call realloc to grow the allocation.
The purpose of this is:
* Only one way to do things
* Changing a function with void return type to return a possible
error becomes a 1 character change, subtly encouraging
people to use errors.
See #632
Here are some imperfect sed commands for performing this update:
remove arrow:
```
sed -i 's/\(\bfn\b.*\)-> /\1/g' $(find . -name "*.zig")
```
add void:
```
sed -i 's/\(\bfn\b.*\))\s*{/\1) void {/g' $(find ../ -name "*.zig")
```
Some cleanup may be necessary, but this should do the bulk of the work.
