38 lines
1.7 KiB
Rust
38 lines
1.7 KiB
Rust
// This file is part of libfringe, a low-level green threading library.
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// Copyright (c) edef <edef@edef.eu>
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// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
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// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
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// http://opensource.org/licenses/MIT>, at your option. This file may not be
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// copied, modified, or distributed except according to those terms.
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//! Traits for stacks.
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/// A trait for objects that hold ownership of a stack.
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///
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/// To preserve memory safety, an implementation of this trait must fulfill
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/// the following contract:
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///
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/// * The base of the stack must be aligned to a platform-specific boundary.
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/// * Every address between the base and the limit must be readable and writable.
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///
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/// On any platform supported by libfringe, it is safe to align the stack to a 16-byte boundary.
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/// The platform ABI document lists the specific alignment requirement.
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pub trait Stack {
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/// Returns the base of the stack.
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/// On all modern architectures, the stack grows downwards,
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/// so this is the highest address.
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fn base(&self) -> *mut u8;
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/// Returns the limit of the stack.
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/// On all modern architectures, the stack grows downwards,
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/// so this is the lowest address.
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fn limit(&self) -> *mut u8;
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}
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/// A marker trait for `Stack` objects with a guard page.
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///
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/// To preserve memory safety, an implementation of this trait must fulfill
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/// the following contract, in addition to the [contract](trait.Stack.html) of `Stack`:
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///
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/// * Any access of data at addresses `limit()` to `limit().offset(4096)` must
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/// abnormally terminate, at least, the thread that performs the access.
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pub unsafe trait GuardedStack {}
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