[FIXED] How to tokio::join multiple tasks?

Issue

Imagine that some futures are stored in a Vec whose length are runtime-determined, you are supposed to join these futures concurrently, what should you do?

Obviously, by the example in the document of tokio::join, manually specifying each length the Vec could be, like 1, 2, 3, ... and dealing with respectable case should work.

extern crate tokio;

let v = Vec::new();
v.push(future_1);

// directly or indirectly you push many futures to the vector
 
v.push(future_N);

// to join these futures concurrently one possible way is 

if v.len() == 0 {}
if v.len() == 1 { join!(v.pop()); }
if v.len() == 2 { join!(v.pop(), v.pop() ); }
// ...

And I also noticed that tokio::join! take a list as parameter in the document, when I use syntax like

tokio::join!(v);

or something like

tokio::join![ v ] /  tokio::join![ v[..] ] / tokio::join![ v[..][..] ]

it just doesn't work

And here comes the question that is there any doorway to join these futures more efficient or should I miss something against what the document says?

Solution

You can use futures::future::join_all to "merge" your collection of futures together into a single future, that resolves when all of the subfutures resolve.

Answered By - Colonel Thirty Two

Answer Checked By - Willingham (PHPFixing Volunteer)