https://issues.dlang.org/show_bug.cgi?id=18063

Ali Cehreli <acehreli@yahoo.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |pull

--- Comment #1 from Ali Cehreli <acehreli@yahoo.com> ---
https://github.com/dlang/druntime/pull/1986

--

https://issues.dlang.org/show_bug.cgi?id=18063

--- Comment #2 from Ali Cehreli <acehreli@yahoo.com> ---
New PR:

  https://github.com/dlang/druntime/pull/1989

--

https://issues.dlang.org/show_bug.cgi?id=18063

--- Comment #3 from Dlang Bot <dlang-bot@dlang.rocks> ---
@MoonlightSentinel created dlang/druntime pull request #2966 "Revive 1989: Thread detach stability" fixing this issue:

- Issue 18063 - Do not pthread_detach non-D threads

- Fix issue 18063 - thread_attachThis returns dangling pointer

https://github.com/dlang/druntime/pull/2966

--

https://issues.dlang.org/show_bug.cgi?id=18063

Ali Cehreli <acehreli@yahoo.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://issues.dlang.org/sh
                   |                            |ow_bug.cgi?id=22358

--

https://issues.dlang.org/show_bug.cgi?id=18063

thomas.bockman@gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |thomas.bockman@gmail.com

--- Comment #4 from thomas.bockman@gmail.com ---
It appears to be a race condition between `thread_attachThis` and `GC.collect`. Serializing them prevents the crash:

//////////////////////////////////////////////////
import core.sys.posix.pthread;
import core.memory;
import core.sync.mutex;
import core.thread;
import std.stdio;

enum allocCount = 1000;
enum allocSize = 1000;
enum threadCount = 100;
enum collectCount = 1000;

shared Mutex serialize;
shared static this() {
    serialize = new shared Mutex;
}

extern(C) void* foo(void*)
{
    serialize.lock_nothrow();
    thread_attachThis();
    serialize.unlock_nothrow();

    scope(exit)
        thread_detachThis();

    foreach(_; 0..allocCount) {
        new int;
        new int[allocSize];
    }

    writeln(`foo done`);
    return null;
}

void main()
{
    pthread_t thread;

    foreach(_; 0..threadCount) {
        auto status = pthread_create(&thread, null, &foo, null);
        assert(status == 0);

        foreach(i; 0..collectCount) {
            serialize.lock_nothrow();
            GC.collect();
            serialize.unlock_nothrow();
        }

        pthread_join(thread, null);
    }

    writeln(`main done`);
}
//////////////////////////////////////////////////

--

https://issues.dlang.org/show_bug.cgi?id=18063

--- Comment #5 from thomas.bockman@gmail.com ---
(In reply to thomas.bockman from comment #4)
> It appears to be a race condition between `thread_attachThis` and `GC.collect`. Serializing them prevents the crash:

Oops, I meant to submit that to bug 22358: https://issues.dlang.org/show_bug.cgi?id=22358

--

https://issues.dlang.org/show_bug.cgi?id=18063

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P1                          |P2

--