Add `bun.ptr.ExternalShared`, a shared pointer whose reference count is
managed externally; e.g., by extern functions. This can be used to work
with `RefCounted` C++ objects in Zig. For example:
```cpp
// C++:
struct MyType : RefCounted<MyType> { ... };
extern "C" void MyType__ref(MyType* self) { self->ref(); }
extern "C" void MyType__ref(MyType* self) { self->deref(); }
```
```zig
// Zig:
const MyType = opaque {
extern fn MyType__ref(self: *MyType) void;
extern fn MyType__deref(self: *MyType) void;
pub const Ref = bun.ptr.ExternalShared(MyType);
// This enables `ExternalShared` to work.
pub const external_shared_descriptor = struct {
pub const ref = MyType__ref;
pub const deref = MyType__deref;
};
};
// Now `MyType.Ref` behaves just like `Ref<MyType>` in C++:
var some_ref: MyType.Ref = someFunctionReturningMyTypeRef();
const ptr: *MyType = some_ref.get(); // gets the inner pointer
var some_other_ref = some_ref.clone(); // increments the ref count
some_ref.deinit(); // decrements the ref count
// decrements the ref count again; if no other refs exist, the object
// is destroyed
some_other_ref.deinit();
```
This commit also adds `RawRefCount`, a simple wrapper around an integer
reference count that can be used to implement the interface required by
`ExternalShared`. Generally, for reference-counted Zig types,
`bun.ptr.Shared` is preferred, but occasionally it is useful to have an
“intrusive” reference-counted type where the ref count is stored in the
type itself. For this purpose, `ExternalShared` + `RawRefCount` is more
flexible and less error-prone than the deprecated `bun.ptr.RefCounted`
type.
(For internal tracking: fixes STAB-1287, STAB-1288)
* Define a generic allocator interface to enable static polymorphism for
allocators (see `GenericAllocator` in `src/allocators.zig`). Note that
`std.mem.Allocator` itself is considered a generic allocator.
* Add utilities to `bun.allocators` for working with generic allocators.
* Add a new namespace, `bun.memory`, with basic utilities for working
with memory and objects (`create`, `destroy`, `initDefault`, `deinit`).
* Add `bun.DefaultAllocator`, a zero-sized generic allocator type whose
`allocator` method simply returns `bun.default_allocator`.
* Implement the generic allocator interface in `AllocationScope` and
`MimallocArena`.
* Improve `bun.threading.GuardedValue` (now `bun.threading.Guarded`).
* Improve `bun.safety.AllocPtr` (now `bun.safety.CheckedAllocator`).
(For internal tracking: fixes STAB-1085, STAB-1086, STAB-1087,
STAB-1088, STAB-1089, STAB-1090, STAB-1091)
* `IncrementalGraph(.client).File` packs its fields in a specific way to
save space, but it makes the struct hard to use and error-prone (e.g.,
untagged unions with tags stored in a separate `flags` struct). This PR
changes `File` to have a human-readable layout, but adds methods to
convert it to and from `File.Packed`, a packed version with the same
space efficiency as before.
* Reduce the need to pass the dev allocator to functions (e.g.,
`deinit`) by storing it as a struct field via the new `DevAllocator`
type. This type has no overhead in release builds, or when
`AllocationScope` is disabled.
* Use owned pointers in `PackedMap`.
* Use `bun.ptr.Shared` for `PackedMap` instead of the old
`bun.ptr.RefPtr`.
* Add `bun.ptr.ScopedOwned`, which is like `bun.ptr.Owned`, but can
store an `AllocationScope`. No overhead in release builds or when
`AllocationScope` is disabled.
* Reduce redundant allocators in `BundleV2`.
* Add owned pointer conversions to `MutableString`.
* Make `AllocationScope` behave like a pointer, so it can be moved
without invalidating allocations. This eliminates the need for
self-references.
* Change memory cost algorithm so it doesn't rely on “dedupe bits”.
These bits used to take advantage of padding but there is now no padding
in `PackedMap`.
* Replace `VoidFieldTypes` with `useAllFields`; this eliminates the need
for `voidFieldTypesDiscardHelper`.
(For internal tracking: fixes STAB-1035, STAB-1036, STAB-1037,
STAB-1038, STAB-1039, STAB-1040, STAB-1041, STAB-1042, STAB-1043,
STAB-1044, STAB-1045)
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Add a new reference-counted shared pointer type, `bun.ptr.Shared`.
Features:
* Can hold data of any type; doesn't require adding a `ref_count` field
* Reference count is an internal implementation detail; will never get
out of sync due to erroneous manipulation
* Supports weak pointers
* Supports optional pointers with no overhead (`Shared(?*T)` is the same
size as `Shared(*T)`)
* Has an atomic thread-safe version: `bun.ptr.AtomicShared`
* Defaults to `bun.default_allocator`, but can handle other allocators
as well, with both static and dynamic polymorphism
The following types are now deprecated and will eventually be removed:
* `bun.ptr.RefCount`
* `bun.ptr.ThreadSafeRefCount`
* `bun.ptr.RefPtr`
* `bun.ptr.WeakPtr`
(For internal tracking: fixes STAB-1011)
Add an owned pointer type—a wrapper around a pointer and an allocator.
`Owned(*Foo)` and `Owned([]Foo)` contain both the pointer/slice and the
allocator that was used to allocate it. Calling `deinit` on these types
first calls `Foo.deinit` and then frees the memory. This makes it easier
to remember to free the memory, and hard to accidentally free it with
the wrong allocator.
Optional pointers are also supported (`Owned(?*Foo)`, `Owned(?[]Foo)`),
and an unmanaged variant which doesn't store the allocator
(`Owned(*Foo).Unmanaged`) is available for cases where space efficiency
is a concern.
A `MaybeOwned` type is also provided for representing data that could be
owned or borrowed. If the data is owned, `MaybeOwned.deinit` works like
`Owned.deinit`; otherwise, it's a no-op.
(For internal tracking: fixes STAB-920, STAB-921)
* Move `DebugThreadLock` to `bun.safety`
* Enable in `ci_assert` builds, but store stack traces only in debug
builds
* Reduce size of struct by making optional field non-optional
* Add `initLockedIfNonComptime` as a workaround for not being able to
call `initLocked` in comptime contexts
* Add `lockOrAssert` method to acquire the lock if unlocked, or else
assert that the current thread acquired the lock
* Add stack traces to `CriticalSection` and `AllocPtr` in debug builds
* Make `MimallocArena.init` infallible
* Make `MimallocArena.heap` non-nullable
* Rename `RefCount.active_counts` to `raw_count` and provide read-only
`get` method
* Add `bun.safety.alloc.assertEq` to assert that two allocators are
equal (avoiding comparison of undefined `ptr`s)
(For internal tracking: fixes STAB-917, STAB-918, STAB-962, STAB-963,
STAB-964, STAB-965)
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
