Bug#581700: [libphobos-4.1-dev] Not started Threads cause Segfault on exit
While trying to narrow down another bug (#581698) I noticed that my
program segfaults on exit, if there are Thread-objects that haven't
While it probably doesn't make much sense to create Threads and not
start them, this shouldn't happen.
I ran it with gdb and got the following backtrace:
Program received signal SIGSEGV, Segmentation fault.
0xb7f6292b in pthread_detach () from /lib/i686/cmov/libpthread.so.0
#0 0xb7f6292b in pthread_detach () from /lib/i686/cmov/libpthread.so.0
#1 0x0805ad93 in _d_callfinalizer ()
#2 0x0805c5a6 in _D3gcx3Gcx11fullcollectMFPvZk ()
#3 0x0805ca54 in _D3gcx3Gcx16fullcollectshellMFZk ()
#4 0x0805cd8c in _D3gcx2GC18fullCollectNoStackMFZv ()
#5 0x0805a203 in gc_term ()
#6 0x0806166a in _d_run_main ()
#7 0x0805e33a in main ()
I think (but haven't tried to fix that yet) that the error is in
Thread's destructor (std/thread.d line 589/590):
if (state != TS.FINISHED)
The status of an unstarted Thread is TS.INITIAL - I don't know if it
is necessary to pthread_detach() a thread that hasn't run,
but if it isn't I'd suggest to change this to
if(state != TS.FINISHED && state != TS.INITIAL)
This Bug also applies gdc-4.3 and Digitalmars dmd.
I've attached a simple example to demonstrate the bug.
--- System information. ---
Kernel: Linux 2.6.32-3-686
Debian Release: squeeze/sid
500 testing security.debian.org
500 testing ftp.de.debian.org
--- Package information. ---
Depends (Version) | Installed
gdc-4.1 (= 0.25-4.1.2-27) | 0.25-4.1.2-27
zlib1g-dev (>= 1:220.127.116.11) | 1:18.104.22.168.dfsg-3
Package's Recommends field is empty.
Package's Suggests field is empty.
const bool doSegfault=true;
int delegate() dg = &fun;
Thread t = new Thread(dg);
// if t.start() is missing, the program segfaults on exit (all compilers),
// probably because of pthread_detach in Threads destructor
// - is pthread_detach necessary when state == TS.INITIAL?