Implemented MPI_Waitany #88
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| pub fn wait_any<'a, S: Scope<'a>>(requests: &mut Vec<Request<'a, S>>) -> (i32, Status) { | ||
| let mut mpi_requests: Vec<MPI_Request> = Vec::with_capacity(requests.len()); | ||
| let mut scopes: Vec<S> = Vec::with_capacity(requests.len()); | ||
| unsafe { |
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reduce the scope of this unsafe - be more targeted in where you apply it.
src/request.rs
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| let mut scopes: Vec<S> = Vec::with_capacity(requests.len()); | ||
| unsafe { | ||
| let mut index: i32 = mpi_sys::MPI_UNDEFINED; | ||
| while let Some(r) = requests.pop() { |
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Rather than draining the requests object and then re-filling it, could you instead just build the mpi_requests objects using as_raw?
e.g.
let mut mpi_requests: Vec<_> = requests.iter().map(|r| r.as_raw()).collect();Then after MPI_Waitany succeeds, just do requests.remove(index);. You'll need to make sure that there's no panic between MPI_Waitany and the remove call.
I think this approach has two benefits:
- Eliminates the allocation of the
scopesvector - Fewer moves in the
requestsvector.
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Oh, you're also not reversing the list and then don't have to deal with fixing up the index.
src/request.rs
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| /// | ||
| /// The completed request is removed from the vector of requests. | ||
| /// | ||
| /// If no Request is active the index returned is mpi_sys::MPI_UNDEFINED. |
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return an Option<(i32, Status)> instead - prefer Rust idioms when there's a clear mapping.
src/request.rs
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| /// # Examples | ||
| /// | ||
| /// See `examples/wait_any.rs` | ||
| pub fn wait_any<'a, S: Scope<'a>>(requests: &mut Vec<Request<'a, S>>) -> (i32, Status) { |
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Let's actually make this a usize - we're already checking that it's convertible anyway.
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By the way, stay strong. America stands with Italy! |
…urn type to Optio<(usize,Status)>
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Thank you Andrew, I hope the situation there in America don't get as bad as here. I've fixed the problems you have spotted in the implementation. |
I needed the MPI_Waitany for a personal project so I decided to implement it as a function in the Request module. This is the first time i work with ffi and unsafe code so I tried to keep things as simple as possible.
I'm not sure if using a Vec of Request as input parameter and removing the completed Request from it is the best way to go but it was the simplest I could find.