---- Reported by 2006-09-20 22:16:57 MST ---- Please fill in this template when reporting a bug, unless you know what you are doing. Description of Problem: we've seen several cases where our C# program has finished the last line of main() but we never get back to the Linux prompt as mono appears to be hung. When it's in this state, we can't run any other mono programs until the "hanging" one is killed. Is it possible that the mono runtime has a lock somewhere which prevents other instances from running it and when one runtime instance is holding the lock forever?? Steps to reproduce the problem: we haven't yet been able to consistently reproduce this, but we've seen it several time. killing the one that is hung frees everthing up. We'll keep trying, but thought it was worth entering the bug. Perhaps there is something we can do to troubleshoot it when it gets in this state. Actual Results: Expected Results: How often does this happen? every once in a while Additional Information: ---- Additional Comments From 2006-09-21 11:03:43 MST ---- This looks like an issue with the io-layer. When it happens again, please attach gdb to the hanging mono process and get a backtrace of all the threads (type 'thread apply all bt' at the gdb prompt). Also, what preecise version of mono are you using (mono --version)? ---- Additional Comments From 2006-09-21 13:06:37 MST ---- Will do (the gdb bit). We're using 1.1.13.8. ---- Additional Comments From 2006-09-26 13:21:41 MST ---- I encountered the hang again. There are 2 mono processes. The first yields: (gdb) thread apply all bt (gdb) bt #0 0x0038a410 in ?? () #1 0xbfb79858 in ?? () #2 0x00000000 in ?? () The 2nd process seems to have more info: (gdb) thread apply all bt Thread 5 (Thread -1213420640 (LWP 14556)): #0 0x0038a410 in ?? () #1 0xb7aca388 in ?? () #2 0x00000001 in ?? () #3 0x00ad8011 in ?? () #4 0x0047236d in semop () from /lib/libc.so.6 #5 0x080fe496 in _wapi_shm_sem_lock (sem=-4) at shared.c:483 #6 0x081042de in _wapi_handle_update_refs () at ../../mono/io-layer/handles-private.h:319 #7 0x080fe5f5 in collection_thread (unused=0x0) at collection.c:37 #8 0x007b040b in start_thread () from /lib/libpthread.so.0 #9 0x00470b7e in clone () from /lib/libc.so.6 Thread 4 (Thread -1218552928 (LWP 14557)): #0 0x0038a410 in ?? () #1 0xb75e5270 in ?? () #2 0x0000866b in ?? () #3 0x00000000 in ?? () Thread 3 (Thread -1222575200 (LWP 14559)): #0 0x0038a410 in ?? () #1 0xb720ef94 in ?? () ---Type to continue, or q to quit--- #2 0x00008b93 in ?? () #3 0x00000000 in ?? () Thread 2 (Thread -1225593952 (LWP 14560)): #0 0x0038a410 in ?? () #1 0xb6f2e458 in ?? () #2 0xb6f2e338 in ?? () #3 0xb6f2e3b8 in ?? () #4 0x00469e11 in ___newselect_nocancel () from /lib/libc.so.6 #5 0xb6fca3cc in Tcl_InitNotifier () from /usr/lib/libtcl8.4.so #6 0x007b040b in start_thread () from /lib/libpthread.so.0 #7 0x00470b7e in clone () from /lib/libc.so.6 Thread 1 (Thread -1208580416 (LWP 14555)): #0 0x0038a410 in ?? () #1 0xbff1ab40 in ?? () #2 0x081be970 in __JCR_LIST__ () #3 0xbff1ab18 in ?? () #4 0x007b60d8 in recvfrom () from /lib/libpthread.so.0 #5 0x080f72de in _wapi_recvfrom (fd=9, buf=0x8458560, len=1024, recv_flags=0, from=0x0, fromlen=0x0) at sockets.c:498 #6 0x080f7234 in _wapi_recv (fd=4294966784, buf=0xfffffe00, len=4294966784, recv_flags=-512) at sockets.c:478 ---Type to continue, or q to quit--- #7 0x080baa47 in ves_icall_System_Net_Sockets_Socket_Receive_internal ( sock=4294966784, buffer=0xbff1ab18, offset=136046960, count=1024, flags=-512, error=0xbff1ac00) at socket-io.c:1212 #8 0xb721eedb in ?? () #9 0x00000009 in ?? () #10 0x08458550 in ?? () #11 0x00000000 in ?? () (gdb) ---- Additional Comments From