Using Chan from a thread created from a c library crashes after sometime

[arturoc]

Reporting this here after asking in IRC

something like this:

spawn(proc(){    
    let (port,chan): (comm::Port<Message>, comm::Chan<Message>) = comm::Chan::new();
    let mut chan = ~chan;
    set_c_callback(c_callback, cast::transmute(&mut *chan));
});

extern "C" fn c_callback (data: *c_void){
    unsafe{
    let channel = data as *mut comm::Chan<Message>;
        (*channel).send(MessageType);
    }
}

where c_callback is called from a thread created by the c library crashes the application after a while with:

fatal runtime error: assertion failed: !ptr.is_null()

Program received signal SIGILL, Illegal instruction.
[Switching to Thread 0x7fffd7fff700 (LWP 28971)]
0x0000000000483d4b in rt::util::abort::h66e24f48938afe6eMim::v0.10.pre ()
(gdb) bt
#0 0x0000000000483d4b in rt::util::abort::h66e24f48938afe6eMim::v0.10.pre ()
#1 0x00000000007b73d1 in rt::local_ptr::compiled::take::he8a5e3f0ec45f53amAs::v0.1 ()
#2 0x00000000007c7778 in comm::Chan$LT$T$GT$::send::hfedc51b572bd5818fot::v0.1 ()
...

previously SharedChan seemed to work without problem

[huonw]

cc @alexcrichton

It looks like the new std::comm can no longer be used outside a runtime?

[alexcrichton]

Whoops, testing a fix now (sorry about that!)

[arturoc]

thanks!

[arturoc]

sorry to post on a closed issue, but i'm finding the same problem now in SyncChan/SyncPort not sure if it's a real bug or in this case it's supposed to work like that?

[alexcrichton]

You won't be able to use those off the runtime because a send involves then receiving which blocks the task. You're only able to block if you have a local rust task available.

[arturoc]

that's what i was suspecting, thanks!