7d756e44a9
Most of the comments are available on the Task structure itself, but this commit is aimed at making FFI-style usage of Rust tasks a little nicer. Primarily, this commit enables re-use of tasks across multiple invocations. The method `run` will no longer unconditionally destroy the task itself. Rather, the task will be internally re-usable if the closure specified did not fail. Once a task has failed once it is considered poisoned and it can never be used again. Along the way I tried to document shortcomings of the current method of tearing down a task, opening a few issues as well. For now none of the behavior is a showstopper, but it's useful to acknowledge it. Also along the way I attempted to remove as much `unsafe` code as possible, opting for safer abstractions.
54 lines
1.2 KiB
Rust
54 lines
1.2 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::task;
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use std::gc::{GC, Gc};
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use std::cell::RefCell;
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static mut DROPS: uint = 0;
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struct Foo(bool);
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impl Drop for Foo {
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fn drop(&mut self) {
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let Foo(fail) = *self;
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unsafe { DROPS += 1; }
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if fail { fail!() }
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}
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}
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fn tld_fail(fail: bool) {
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local_data_key!(foo: Foo);
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foo.replace(Some(Foo(fail)));
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}
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fn gc_fail(fail: bool) {
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struct A {
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inner: RefCell<Option<Gc<A>>>,
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other: Foo,
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}
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let a = box(GC) A {
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inner: RefCell::new(None),
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other: Foo(fail),
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};
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*a.inner.borrow_mut() = Some(a.clone());
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}
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fn main() {
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let _ = task::try(proc() {
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tld_fail(true);
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gc_fail(false);
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});
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unsafe {
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assert_eq!(DROPS, 2);
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}
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}
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