On 04/14/2012 04:56 PM, Alex Rønne Petersen wrote:
On 14-04-2012 18:04, Russel Winder wrote:
I thought the following would terminate gracefully having printed 0..9
in some (random) order:
#! /usr/bin/env rdmd
import std.algorithm ;
import std.range ;
import std.stdio ;
import core.thread ;
int main ( immutable string[] args ) {
auto threads = map ! ( ( int a ) {
void delegate ( ) f ( ) {
return delegate ( ) { writeln ( a ) ; } ;
}
return new Thread ( f ) ;
} ) ( iota ( 10 ) ) ;
foreach ( t ; threads ) { t.start ( ) ; }
foreach ( t ; threads ) { t.join ( ) ; }
return 0 ;
}
However, this does not happen, at least with 2.059 on Linux as per
Debian Unstable. Instead I get:
1
2
4
5
8
3
7
6
9
0
core.thread.ThreadException@src/core/thread.d(906): Unable to join thread
----------------
/tmp/.rdmd-1000/home/users/russel/Progs/OddsByLanguage/D/Odds/initializingWithAMap.d.9532BBED12C814F25F173A9AEAB96D0D(_Dmain+0x83)
[0x425edb]
/tmp/.rdmd-1000/home/users/russel/Progs/OddsByLanguage/D/Odds/initializingWithAMap.d.9532BBED12C814F25F173A9AEAB96D0D(extern
(C) int rt.dmain2..main(int, char**).void runMain()+0x17) [0x429bab]
/tmp/.rdmd-1000/home/users/russel/Progs/OddsByLanguage/D/Odds/initializingWithAMap.d.9532BBED12C814F25F173A9AEAB96D0D(extern
(C) int rt.dmain2..main(int, char**).void tryExec(scope void
delegate())+0x23) [0x42952b]
/tmp/.rdmd-1000/home/users/russel/Progs/OddsByLanguage/D/Odds/initializingWithAMap.d.9532BBED12C814F25F173A9AEAB96D0D(extern
(C) int rt.dmain2..main(int, char**).void runAll()+0x3d) [0x429bf9]
/tmp/.rdmd-1000/home/users/russel/Progs/OddsByLanguage/D/Odds/initializingWithAMap.d.9532BBED12C814F25F173A9AEAB96D0D(extern
(C) int rt.dmain2..main(int, char**).void tryExec(scope void
delegate())+0x23) [0x42952b]
/tmp/.rdmd-1000/home/users/russel/Progs/OddsByLanguage/D/Odds/initializingWithAMap.d.9532BBED12C814F25F173A9AEAB96D0D(main+0xd3)
[0x4294c3]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xfd) [0x7f1ed17f8ead]
----------------
I think I must be having a dumb moment as my reaction continues to be
WTF.
http://www.kernel.org/doc/man-pages/online/pages/man3/pthread_join.3.html#ERRORS
We can rule out these:
EDEADLK: Can't happen with your code.
EINVAL (second case): No other thread is trying to join.
ESRCH: Shouldn't happen since druntime registers threads with libpthread.
So, the first case of EINVAL (thread is not a joinable thread) must be
the cause. I have no clue *why* though...
If you merge the two foreach loops into one, doing t.start();t.join();
it doesn't have this issue. Also, when I run your code repeatedly the
number of successful numbers printed changes a lot.
I'm assuming that you're trying to join a thread that already exited...
-Matt
