Program locked at joinAll and sched_yield

[tcak via Digitalmars-d-learn]

I have my own Http Server. Every request is handled by a thread, 
and threads are reused.

I send 35,000 request (7 different terminals are sending 5000 
requests each) to the server again and again (each of them lives 
for short).

Anyway, everything works great, there is no problem at all.

I put "readln" in main function. So, when I press enter, all 
currently idle threads are stopped. (I use thread.join()).

Problem is that, all threads are stopped, by the last thread 
Thread#1 gets locked at sched_yield(), it uses one of CPU cores 
at 100%, and program never quits and stays there.

There is only one remaining thread at the end, and below is its 
stack trace.

sched_yield() in 
/build/glibc-GKVZIf/glibc-2.23/posix/../sysdeps/unix/syscall-template.S:84

thread_joinAll() in

rt_term() in

rt.dmain2._d_run_main(int, char**, extern(C) int(char[][]) 
function).runAll()() in

rt.dmain2._d_run_main(int, char**, extern(C) int(char[][]) 
function).tryExec(scope void() delegate)() in

_d_run_main() in

main() in

__libc_start_main(int (*)(int, char **, char **) main, int argc, 
char ** argv, int (*)(int, char **, char **) init, void (*)(void) 
fini, void (*)(void) rtld_fini, void * stack_end) in 
/build/glibc-GKVZIf/glibc-2.23/csu/../csu/libc-start.c:291

_start() in


Is there any known issue about this? or anything that is known to 
cause this problem?