native::start does not join all spawned tasks

[huonw]

As demonstrated by the following program, which only prints hi at the mercy of the OS scheduler (taking the 10_000 to 0 makes it never print, and making it large makes it always print, as one would expect).

#[feature(asm)];

extern mod native;

#[start]
fn start(argc: int, argv: **u8) -> int {
    native::start(argc, argv, proc() {
            spawn(proc() println("hi"));

            for _ in range(0, 10_000) { unsafe {asm!("")} }
        });
    0
}

$ rustc -O native-spawn.rs
$ for i in {0..10}; do echo $i $(./native-spawn); done
0
1
2
3
4 hi
5 hi
6 hi
7 hi
8
9 hi
10 hi

Replacing libnative with libgreen prints every time, even with no busy loop.

[huonw]

cc @alexcrichton

[alexcrichton]

Hm, I tried to reproduce this, but I think OSX must always immediately schedule a child thread as opposed to sometimes not. I think I found the bug, but can you make sure that this commit fixes it for you?

alexcrichton@3a271c8

[huonw]

It looks like it does.

[alexcrichton]

Closed by 9c8813f