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//! jlrs provides access to most of the Julia C API, it can be used to embed Julia in Rust //! applications and to use functionality from the Julia C API when writing `ccall`able functions. //! Currently this crate is only tested on Linux in combination with Julia 1.6 and is not //! compatible with earlier versions of Julia. //! //! The documentation assumes you have at least a basic understanding of Julia's type system. //! //! # Features //! //! An incomplete list of features that are currently supported by jlrs: //! //! - Access arbitrary Julia modules and their contents. //! - Call Julia functions, including functions that take keyword arguments. //! - Include and call your own Julia code. //! - Load a custom system image. //! - Create values that Julia can use, and convert them back to Rust, from Rust. //! - Access the type information and fields of values. //! - Create and use n-dimensional arrays. //! - Support for mapping Julia structs to Rust structs that can be generated by JlrsReflect.jl. //! - Structs that can be mapped to Rust include those with type parameters and bits unions. //! - Offload long-running functions to another thread and `.await` the result with the //! (experimental) async runtime. //! //! //! # Generating the bindings //! //! This crate depends on jl-sys which contains the raw bindings to the Julia C API, these are //! generated by bindgen. You can find the requirements for using bindgen in [their User Guide]. //! //! #### Linux //! //! The recommended way to install Julia is to download the binaries from the official website, //! which is distributed in an archive containing a directory called `julia-x.y.z`. This directory //! contains several other directories, including a `bin` directory containing the `julia` //! executable. //! //! In order to ensure the `julia.h` header file can be found, either `/usr/include/julia/julia.h` //! must exist, or you have to set the `JULIA_DIR` environment variable to `/path/to/julia-x.y.z`. //! This environment variable can be used to override the default. Similarly, in order to load //! `libjulia.so` you must add `/path/to/julia-x.y.z/lib` to the `LD_LIBRARY_PATH` environment //! variable. //! //! #### Windows //! //! If you want to use jlrs on Windows you must use WSL. An installation guide to install WSL on //! Windows can be found [on Microsoft's website]. After installing a Linux distribution, follow //! the installation instructions for Linux. //! //! # Using this crate //! //! The first thing you should do is `use` the [`prelude`]-module with an asterisk, this will //! bring all the structs and traits you're likely to need into scope. When embedding Julia, it //! must be initialized before you can use it. You can do this by calling [`Julia::init`] which //! returns an instance of [`Julia`]. Note that this method can only be called once while the //! application is running; if you drop it you won't be able to create a new instance but have to //! restart the application. If you want to use a custom system image, you must call //! [`Julia::init_with_image`] instead of `Julia::init`. If you're calling Rust from Julia //! everything has already been initialized, you can use `CCall` instead. //! //! //! ## Calling Julia from Rust //! //! After initialization you have an instance of [`Julia`], [`Julia::include`] can be used to //! include files with custom Julia code. In order to call Julia functions and create new values //! that can be used by these functions, [`Julia::scope`] and [`Julia::scope_with_slots`] must be //! used. These two methods take a closure with two arguments, a [`Global`] and a mutable //! reference to a [`GcFrame`]. `Global` is a token that is used to access Julia modules, their //! contents and other global values, while `GcFrame` is used to root local values. Rooting a //! value in a frame prevents it from being freed by the garbage collector until that frame has //! been dropped. The frame is created when `Julia::scope(_with_slots)` is called and dropped //! when that method returns. //! //! Because you can use both a `Global` and a mutable reference to a `GcFrame` inside the closure, //! it's possible to access the contents of modules and create new values that can be used by //! Julia. The methods of [`Module`] let you access the contents of arbitrary modules, several //! methods are available to create new values. //! //! The simplest is to call [`Value::eval_string`], a method that takes two arguments. The first //! must implement the [`Scope`] trait, the second is a string which has to contain valid Julia //! code. The most important thing to know about the [`Scope`] trait for now is that it's used //! by functions that create new values to ensure the result is rooted. Mutable references to //! [`GcFrame`]s implement [`Scope`], in this case the [`Value`] that is returned is rooted in //! that frame, so the result is protected from garbage collection until the frame is dropped when //! that scope ends. //! //! In practice, [`Value::eval_string`] is relatively limited. It can be used to evaluate simple //! function calls like `sqrt(2.0)`, but can't take any arguments. Its most important use-case is //! importing installed packages by evaluating an `import` or `using` statement. A more //! interesting method, [`Value::new`], can be used with data of any type that implements //! [`IntoJulia`]. This trait is implemented by primitive types like `i8` and `char`. Any type //! that implements [`IntoJulia`] also implements [`Unbox`] which is used to extract the contents //! of a Julia value. //! //! In addition to evaluating raw commands with `Value::eval_string`, it's possible to call //! anything that implements [`Call`] as a Julia function, `Value` implements this trait because //! any Julia value is potentially callable as a function. Functions can be called with any number //! of positional arguments and be provided with keyword arguments. Both `Value::eval_string` and //! the trait methods of `Call` are all unsafe. It's trivial to write a function like //! `boom() = unsafe_load(Ptr{Float64}(C_NULL))`, which causes a segfault when it's called, and //! call it with these methods. //! //! As a simple example, let's convert two numbers to Julia values and add them: //! //! ```no_run //! use jlrs::prelude::*; //! //! # fn main() { //! // Initializing Julia is unsafe because it can race with another crate that does //! // the same. //! let mut julia = unsafe { Julia::init().unwrap() }; //! let res = julia.scope(|global, frame| { //! // Create the two arguments. Note that the first argument, something that //! // implements Scope, is taken by value and mutable references don't implement //! // Copy, so it's necessary to mutably reborrow the frame. //! let i = Value::new(&mut *frame, 2u64)?; //! let j = Value::new(&mut *frame, 1u32)?; //! //! // The `+` function can be found in the base module. //! let func = Module::base(global).function(&mut *frame, "+")?; //! //! // Call the function and unbox the result as a `u64`. The result of the function //! // call is a nested `Result`; the outer error doesn't contain to any Julia //! // data, while the inner error contains the exception if one is thrown. Here we //! // explicitly convert the exception to an error that is compatible with `?`. //! unsafe { //! func.call2(&mut *frame, i, j)? //! .into_jlrs_result()? //! .unbox::<u64>() //! } //! }).unwrap(); //! //! assert_eq!(res, 3); //! # } //! ``` //! //! Many more features are available, including creating and accessing n-dimensional Julia arrays //! and nesting scopes. To learn how to use them, please see the documentation for the [`memory`] //! and [`wrappers`] modules. //! //! //! ## Calling Rust from Julia //! //! Julia's `ccall` interface can be used to call `extern "C"` functions defined in Rust, for most //! use-cases you shouldn't need jlrs. There are two major ways to use `ccall`, with a pointer to //! the function or a `(:function, "library")` pair. //! //! A function can be cast to a void pointer and converted to a [`Value`]: //! //! ```no_run //! # use jlrs::prelude::*; //! // This function will be provided to Julia as a pointer, so its name can be mangled. //! unsafe extern "C" fn call_me(arg: bool) -> isize { //! if arg { //! 1 //! } else { //! -1 //! } //! } //! //! # fn main() { //! let mut julia = unsafe { Julia::init().unwrap() }; //! julia.scope(|global, frame| unsafe { //! // Cast the function to a void pointer //! let call_me_val = Value::new(&mut *frame, call_me as *mut std::ffi::c_void)?; //! //! // Value::eval_string can be used to create new functions. //! let func = Value::eval_string( //! &mut *frame, //! "myfunc(callme::Ptr{Cvoid})::Int = ccall(callme, Int, (Bool,), true)" //! )?.unwrap(); //! //! // Call the function and unbox the result. //! let output = func.call1(&mut *frame, call_me_val)? //! .into_jlrs_result()? //! .unbox::<isize>()?; //! //! assert_eq!(output, 1); //! //! Ok(()) //! }).unwrap(); //! # } //! ``` //! //! You can also use functions defined in `dylib` and `cdylib` libraries. In order to create such //! a library you need to add //! //! ```toml //! [lib] //! crate-type = ["dylib"] //! ``` //! //! or //! //! ```toml //! [lib] //! crate-type = ["cdylib"] //! ``` //! //! respectively to your crate's `Cargo.toml`. Use a `dylib` if you want to use the crate in other //! Rust crates, but if it's only intended to be called through `ccall` a `cdylib` is the better //! choice. On Linux, compiling such a crate will be compiled to `lib<crate_name>.so`. //! //! The functions you want to use with `ccall` must be both `extern "C"` functions to ensure the C //! ABI is used, and annotated with `#[no_mangle]` to prevent name mangling. Julia can find //! libraries in directories that are either on the default library search path or included by //! setting the `LD_LIBRARY_PATH` environment variable on Linux. If the compiled library is not //! directly visible to Julia, you can open it with `Libdl.dlopen` and acquire function pointers //! with `Libdl.dlsym`. These pointers can be called the same way as the pointer in the previous //! example. //! //! If the library is visible to Julia you can access it with the library name. If `call_me` is //! defined in a crate called `foo`, the following should work if the function is annotated with //! `#[no_mangle]`: //! //! ```julia //! ccall((:call_me, "libfoo"), Int, (Bool,), false) //! ``` //! //! One important aspect of calling Rust from other languages in general is that panicking across //! an FFI boundary is undefined behaviour. If you're not sure your code will never panic, wrap it //! with `std::panic::catch_unwind`. //! //! Most features provided by jlrs including accessing modules, calling functions, and borrowing //! array data require a [`Global`] or a frame. You can access these by creating a [`CCall`] //! first. Another method provided by [`CCall`] is [`CCall::uv_async_send`], this method can be //! used in combination with `Base.AsyncCondition`. In particular, it lets you write a `ccall`able //! function that does its actual work on another thread, return early and `wait` on the async //! condition, which happens when [`CCall::uv_async_send`] is called when that work is finished. //! The advantage of this is that the long-running function will not block the Julia runtime, //! There's an example available on GitHub that shows how to do this. //! //! //! ## Async runtime //! //! The experimental async runtime runs Julia in a separate thread and allows multiple tasks to //! run in parallel. This works by offloading functions to a new thread in Julia and waiting for //! them to complete without blocking the runtime. To use this feature you must enable the `async` //! feature flag: //! //! ```toml //! [dependencies] //! jlrs = { version = "0.11", features = ["async"] } //! ``` //! //! The struct [`AsyncJulia`] is exported by the prelude and lets you initialize the runtime in //! two ways, either as a task or as a thread. The first way should be used if you want to //! integrate the async runtime into a larger project that uses `async_std`. In order for the //! runtime to work correctly the `JULIA_NUM_THREADS` environment variable must be set to a value //! larger than 2. //! //! In order to call Julia with the async runtime you must implement the [`AsyncTask`] trait. The //! `run`-method of this trait is similar to the closures that are used in the example //! above for the sync runtime; it provides you with a [`Global`] and an [`AsyncGcFrame`] which //! provides mostly the same functionality as [`GcFrame`]. The `AsyncGcFrame` is required to //! call [`CallAsync::call_async`] which calls a Julia function on another thread by using //! `Base.Threads.@spawn` and returns a `Future`. While awaiting the result the runtime can handle //! another task. If you don't use [`CallAsync::call_async`] tasks are executed sequentially. //! //! It's important to keep in mind that allocating memory in Julia uses a lock, so if you execute //! multiple functions at the same time that allocate new values frequently the performance will //! drop significantly. The garbage collector can only run when all threads have reached a //! safepoint, which is the case whenever a function needs to allocate memory. If your function //! takes a long time to complete but needs to allocate rarely, you should periodically call //! `GC.safepoint` in Julia to ensure the garbage collector can run. //! //! You can find basic examples in [the examples directory of the repo]. //! //! //! # Testing //! //! The restriction that Julia can be initialized once must be taken into account when running //! tests that use `jlrs`. The recommended approach is to create a thread-local static `RefCell`: //! //! ```no_run //! use jlrs::prelude::*; //! use std::cell::RefCell; //! thread_local! { //! pub static JULIA: RefCell<Julia> = { //! let julia = RefCell::new(unsafe { Julia::init().unwrap() }); //! julia.borrow_mut().scope(|_global, _frame| { //! /* include everything you need to use */ //! Ok(()) //! }).unwrap(); //! julia //! }; //! } //! ``` //! //! Tests that use this construct can only use one thread for testing, so you must use //! `cargo test -- --test-threads=1`, otherwise the code above will panic when a test //! tries to call `Julia::init` a second time from another thread. //! //! If these tests also involve the async runtime, the `JULIA_NUM_THREADS` environment //! variable must be set to a value larger than 2. //! //! If you want to run jlrs's tests, both these requirements must be taken into account: //! `JULIA_NUM_THREADS=3 cargo test -- --test-threads=1` //! //! //! # Custom types //! //! In order to map a struct in Rust to one in Julia you can derive [`ValidLayout`], [`Unbox`], //! and [`Typecheck`]. If the struct in Julia has no type parameters and is a bits type you can //! also derive [`IntoJulia`], which lets you use the type in combination with [`Value::new`]. //! //! You should not implement these structs manually. The JlrsReflect.jl package can generate //! the correct Rust struct for types that have no tuple or union fields with type parameters. //! The reason for this restriction is that the layout of tuple and union fields can be very //! different depending on these parameters in a way that can't be expressed in Rust. //! //! These custom types can also be used when you call Rust from Julia with `ccall`. //! //! [their User Guide]: https://rust-lang.github.io/rust-bindgen/requirements.html //! [on Microsoft's website]: https://docs.microsoft.com/en-us/windows/wsl/install-win10 //! [the examples directory of the repo]: https://github.com/Taaitaaiger/jlrs/tree/master/examples //! [`IntoJulia`]: crate::convert::into_julia::IntoJulia //! [`Typecheck`]: crate::layout::typecheck::Typecheck //! [`ValidLayout`]: crate::layout::valid_layout::ValidLayout //! [`Unbox`]: crate::convert::unbox::Unbox //! [`CallAsync::call_async`]: crate::extensions::multitask::call_async::CallAsync //! [`AsyncGcFrame`]: crate::extensions::multitask::async_frame::AsyncGcFrame //! [`Frame`]: crate::memory::frame::Frame //! [`AsyncTask`]: crate::extensions::multitask::async_task::AsyncTask //! [`AsyncJulia`]: crate::extensions::multitask::AsyncJulia //! [`DataType`]: crate::wrappers::ptr::datatype::DataType //! [`TypedArray`]: crate::wrappers::ptr::array::TypedArray //! [`Output`]: crate::memory::output::Output //! [`OutputScope`]: crate::memory::output::OutputScope //! [`ScopeExt`]: crate::memory::scope::ScopeExt //! [`ScopeExt::scope`]: crate::memory::scope::ScopeExt::scope //! [`Scope`]: crate::memory::scope::Scope //! [`Scope::value_scope`]: crate::memory::scope::Scope::value_scope //! [`Scope::result_scope`]: crate::memory::scope::Scope::result_scope #![forbid(broken_intra_doc_links)] pub mod convert; pub mod error; pub mod extensions; pub mod layout; pub mod memory; pub mod prelude; pub(crate) mod private; #[doc(hidden)] pub mod util; pub mod wrappers; use convert::into_jlrs_result::IntoJlrsResult; use error::{JlrsError, JlrsResult, CANNOT_DISPLAY_VALUE}; #[cfg(not(feature = "coverage"))] use jl_sys::uv_async_send; use jl_sys::{jl_atexit_hook, jl_init, jl_init_with_image__threading, jl_is_initialized}; use memory::frame::{GcFrame, NullFrame}; use memory::global::Global; use memory::mode::Sync; use memory::stack_page::StackPage; use prelude::Wrapper; use private::Private; use std::ffi::{c_void, CString}; use std::io::{Error as IOError, ErrorKind}; use std::mem::MaybeUninit; use std::path::Path; use std::ptr::null_mut; use std::sync::atomic::{AtomicBool, Ordering}; use wrappers::ptr::module::Module; use wrappers::ptr::string::JuliaString; use wrappers::ptr::value::Value; use wrappers::ptr::{array::Array, call::Call, private::Wrapper as _}; pub(crate) static INIT: AtomicBool = AtomicBool::new(false); pub(crate) static JLRS_JL: &'static str = include_str!("jlrs.jl"); /// A Julia instance. You must create it with [`Julia::init`] or [`Julia::init_with_image`] /// before you can do anything related to Julia. While this struct exists Julia is active, /// dropping it causes the shutdown code to be called but this doesn't leave Julia in a state from which it can be reinitialized. pub struct Julia { page: StackPage, } impl Julia { /// Initialize Julia, this method can only be called once. If it's called a second time it /// will return an error. If this struct is dropped, you will need to restart your program to /// be able to call Julia code again. /// /// This method is unsafe because it can race with another crate initializing Julia. pub unsafe fn init() -> JlrsResult<Self> { if jl_is_initialized() != 0 || INIT.swap(true, Ordering::SeqCst) { return Err(JlrsError::AlreadyInitialized.into()); } jl_init(); let mut jl = Julia { page: StackPage::default(), }; jl.scope_with_slots(2, |global, frame| { Value::eval_string(&mut *frame, JLRS_JL)?.into_jlrs_result()?; let droparray_fn = Value::new(frame, droparray as *mut c_void)?; Module::main(global) .submodule_ref("Jlrs")? .wrapper_unchecked() .global_ref("droparray")? .wrapper_unchecked() .set_nth_field_unchecked(0, droparray_fn); Ok(()) }) .expect("Could not load Jlrs module"); Ok(jl) } /// This method is similar to [`Julia::init`] except that it loads a custom system image. A /// custom image can be generated with the [`PackageCompiler`] package for Julia. The main /// advantage of using a custom image over the default one is that it allows you to avoid much /// of the compilation overhead often associated with Julia. /// /// Two arguments are required to call this method compared to [`Julia::init`]; /// `julia_bindir` and `image_relative_path`. The first must be the absolute path to a /// directory that contains a compatible Julia binary (eg `${JULIA_DIR}/bin`), the second must /// be either an absolute or a relative path to a system image. /// /// This method will return an error if either of the two paths doesn't exist or if Julia /// has already been initialized. It is unsafe because it can race with another crate /// initializing Julia. /// /// [`PackageCompiler`]: https://julialang.github.io/PackageCompiler.jl/dev/ pub unsafe fn init_with_image<P: AsRef<Path>, Q: AsRef<Path>>( julia_bindir: P, image_path: Q, ) -> JlrsResult<Self> { if INIT.swap(true, Ordering::SeqCst) { Err(JlrsError::AlreadyInitialized)?; } let julia_bindir_str = julia_bindir.as_ref().to_string_lossy().to_string(); let image_path_str = image_path.as_ref().to_string_lossy().to_string(); if !julia_bindir.as_ref().exists() { let io_err = IOError::new(ErrorKind::NotFound, julia_bindir_str); return Err(JlrsError::other(io_err))?; } if !image_path.as_ref().exists() { let io_err = IOError::new(ErrorKind::NotFound, image_path_str); return Err(JlrsError::other(io_err))?; } let bindir = CString::new(julia_bindir_str).unwrap(); let im_rel_path = CString::new(image_path_str).unwrap(); jl_init_with_image__threading(bindir.as_ptr(), im_rel_path.as_ptr()); let mut jl = Julia { page: StackPage::default(), }; jl.scope_with_slots(2, |global, frame| { Value::eval_string(&mut *frame, JLRS_JL)?.into_jlrs_result()?; let droparray_fn = Value::new(&mut *frame, droparray as *mut c_void)?; Module::main(global) .submodule_ref("Jlrs")? .wrapper_unchecked() .global_ref("droparray")? .wrapper_unchecked() .set_nth_field_unchecked(0, droparray_fn); Ok(()) }) .expect("Could not load Jlrs module"); Ok(jl) } /// Calls `include` in the `Main` module in Julia, which executes the file's contents in that /// module. This has the same effect as calling `include` in the Julia REPL. /// /// Example: /// /// ```no_run /// # use jlrs::prelude::*; /// # fn main() { /// # let mut julia = unsafe { Julia::init().unwrap() }; /// julia.include("Path/To/MyJuliaCode.jl").unwrap(); /// # } /// ``` pub fn include<P: AsRef<Path>>(&mut self, path: P) -> JlrsResult<()> { if path.as_ref().exists() { return self.scope_with_slots(2, |global, frame| unsafe { let path_jl_str = JuliaString::new(&mut *frame, path.as_ref().to_string_lossy())?; let include_func = Module::main(global) .function_ref("include")? .wrapper_unchecked(); let res = include_func.call1(frame, path_jl_str)?; return match res { Ok(_) => Ok(()), Err(e) => Err(JlrsError::IncludeError { path: path.as_ref().to_string_lossy().into(), msg: e.display_string_or(CANNOT_DISPLAY_VALUE), })?, }; }); } Err(JlrsError::IncludeNotFound { path: path.as_ref().to_string_lossy().into(), })? } /// This method is a main entrypoint to interact with Julia. It takes a closure with two /// arguments, a `Global` and a mutable reference to a `GcFrame`, and can return arbitrary /// results. /// /// Example: /// /// ``` /// # use jlrs::prelude::*; /// # use jlrs::util::JULIA; /// # fn main() { /// # JULIA.with(|j| { /// # let mut julia = j.borrow_mut(); /// julia.scope(|_global, frame| { /// let _i = Value::new(&mut *frame, 1u64)?; /// Ok(()) /// }).unwrap(); /// # }); /// # } /// ``` pub fn scope<T, F>(&mut self, func: F) -> JlrsResult<T> where for<'base> F: FnOnce(Global<'base>, &mut GcFrame<'base, Sync>) -> JlrsResult<T>, { unsafe { let global = Global::new(); let mut frame = GcFrame::new(self.page.as_mut(), 0, Sync); func(global, &mut frame) } } /// This method is a main entrypoint to interact with Julia. It takes a closure with two /// arguments, a `Global` and a mutable reference to a `GcFrame`, and can return arbitrary /// results. The frame will preallocate `slots` slots. /// /// Example: /// /// ``` /// # use jlrs::prelude::*; /// # use jlrs::util::JULIA; /// # fn main() { /// # JULIA.with(|j| { /// # let mut julia = j.borrow_mut(); /// julia.scope_with_slots(1, |_global, frame| { /// // Uses the preallocated slot /// let _i = Value::new(&mut *frame, 1u64)?; /// // Allocates a new slot, because only a single slot was preallocated /// let _j = Value::new(&mut *frame, 1u64)?; /// Ok(()) /// }).unwrap(); /// # }); /// # } /// ``` pub fn scope_with_slots<T, F>(&mut self, slots: usize, func: F) -> JlrsResult<T> where for<'base> F: FnOnce(Global<'base>, &mut GcFrame<'base, Sync>) -> JlrsResult<T>, { unsafe { let global = Global::new(); if slots + 2 > self.page.size() { self.page = StackPage::new(slots + 2); } let mut frame = GcFrame::new(self.page.as_mut(), slots, Sync); func(global, &mut frame) } } } impl Drop for Julia { fn drop(&mut self) { unsafe { jl_atexit_hook(0); } } } /// When you call Rust from Julia through `ccall`, Julia has already been initialized and trying to /// initialize it again would cause a crash. In order to still be able to call Julia from Rust /// and to borrow arrays (if you pass them as `Array` rather than `Ptr{Array}`), you'll need to /// create a frame first. You can use this struct to do so. It must never be used outside /// functions called through `ccall`, and only once for each `ccall`ed function. /// /// If you only need to use a frame to borrow array data, you can use [`CCall::null_scope`]. /// Unlike [`Julia`], `CCall` postpones the allocation of the stack that is used for managing the /// GC until a `GcFrame` is created. In the case of a null scope, this stack isn't allocated at /// all. pub struct CCall { page: Option<StackPage>, } impl CCall { /// Create a new `CCall`. This function must never be called outside a function called through /// `ccall` from Julia and must only be called once during that call. The stack is not /// allocated until a [`GcFrame`] is created. pub unsafe fn new() -> Self { CCall { page: None } } /// Wake the task associated with `handle`. The handle must be the `handle` field of a /// `Base.AsyncCondition` in Julia. This can be used to call a long-running Rust function from /// Julia with ccall in another thread and wait for it to complete in Julia without blocking, /// there's an example available in the repository: ccall_with_threads. #[cfg(not(feature = "coverage"))] pub unsafe fn uv_async_send(handle: *mut c_void) -> bool { uv_async_send(handle.cast()) == 0 } /// Creates a [`GcFrame`], calls the given closure, and returns its result. pub fn scope<T, F>(&mut self, func: F) -> JlrsResult<T> where for<'base> F: FnOnce(Global<'base>, &mut GcFrame<'base, Sync>) -> JlrsResult<T>, { unsafe { let page = self.get_init_page(); let global = Global::new(); let mut frame = GcFrame::new(page.as_mut(), 0, Sync); func(global, &mut frame) } } /// Creates a [`GcFrame`] with `slots` slots, calls the given closure, and returns its result. pub fn scope_with_slots<T, F>(&mut self, slots: usize, func: F) -> JlrsResult<T> where for<'base> F: FnOnce(Global<'base>, &mut GcFrame<'base, Sync>) -> JlrsResult<T>, { unsafe { let page = self.get_init_page(); let global = Global::new(); if slots + 2 > page.size() { *page = StackPage::new(slots + 2); } let mut frame = GcFrame::new(page.as_mut(), slots, Sync); func(global, &mut frame) } } /// Create a [`NullFrame`] and call the given closure. A [`NullFrame`] cannot be nested and /// can only be used to (mutably) borrow array data. Unlike other scope-methods, no `Global` /// is provided to the closure. pub fn null_scope<'base, 'julia: 'base, T, F>(&'julia mut self, func: F) -> JlrsResult<T> where F: FnOnce(&mut NullFrame<'base>) -> JlrsResult<T>, { unsafe { let mut frame = NullFrame::new(self); func(&mut frame) } } #[inline(always)] fn get_init_page(&mut self) -> &mut StackPage { if self.page.is_none() { self.page = Some(StackPage::default()); } self.page.as_mut().unwrap() } } unsafe extern "C" fn droparray(a: Array) { // The data of a moved array is allocated by Rust, this function is called by // a finalizer in order to ensure it's also freed by Rust. let mut arr_ptr = a.unwrap_non_null(Private); let arr_ref = arr_ptr.as_mut(); if arr_ref.flags.how() != 2 { return; } let data_ptr = arr_ref.data.cast::<MaybeUninit<u8>>(); arr_ref.data = null_mut(); let n_els = arr_ref.elsize as usize * arr_ref.length; Vec::from_raw_parts(data_ptr, n_els, n_els); }