GC deadlocks on linux

I have a medium size daemon application that uses several
threads, libasync, and daemonize.  On windows it runs correctly
with GC enabled, but on linux the GC causes a deadlock while
allocating memory.

Adding core.memory.GC.disable; to main causes the application to
work correctly (and quickly till it runs out of memory :D )

I am running in a vagrant VM for test, but this should not be the
issue.  I am developing this for a future product so I wont have
control over the environment that it runs in.

I am not sure how to debug or work around this issue.  My boss is
a little concerned that I am using D but does think its cool.  I
really want to make this stable and get D in to one of our
products, if not I will have to switch to C++ or even worse JAVA!
  Any help would be appreciated.

-Byron

System:
DMD 2.066.1

Linux vagrant-ubuntu-precise-64 3.2.0-76-virtual #111-Ubuntu SMP
Tue Jan 13 22:3
3:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.04
DISTRIB_CODENAME=precise
DISTRIB_DESCRIPTION="Ubuntu 12.04.5 LTS"
NAME="Ubuntu"
VERSION="12.04.5 LTS, Precise Pangolin"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu precise (12.04.5 LTS)"
VERSION_ID="12.04"

On Wednesday, 18 February 2015 at 20:33:40 UTC, ketmar wrote: > On Wed, 18 Feb 2015 20:27:07 +0000, Byron Heads wrote: > > are you forking? ;-) I am in the daemonize library https://github.com/NCrashed/daemonize

On Wednesday, 18 February 2015 at 20:41:12 UTC, Dicebot wrote: > Any chance you are using gdm-3.12.x? > > I was so mad when I have encountered this: > https://issues.dlang.org/show_bug.cgi?id=4890 Dont think so $dpkg --get-selections | grep gdm doesn't return anything also running via ssh

On Wed, 18 Feb 2015 20:35:44 +0000, Byron Heads wrote: > On Wednesday, 18 February 2015 at 20:33:40 UTC, ketmar wrote: >> On Wed, 18 Feb 2015 20:27:07 +0000, Byron Heads wrote: >> >> are you forking? ;-) > > > I am in the daemonize library > > https://github.com/NCrashed/daemonize can you drop that and just let the program run on foreground? i suspect that it may solve your problem. you can detach your program with "setsid" and "&" to avoid forking. `fork()` is a very fragile thing, and it may be the source of heisenbugs. stop `fork()`ing may be the easiest solution (if it solves something, of course ;-).

On Wed, 18 Feb 2015 20:35:44 +0000, Byron Heads wrote: > On Wednesday, 18 February 2015 at 20:33:40 UTC, ketmar wrote: >> On Wed, 18 Feb 2015 20:27:07 +0000, Byron Heads wrote: >> >> are you forking? ;-) > > > I am in the daemonize library > > https://github.com/NCrashed/daemonize p.s. and check if you don't disable signals. druntime uses SIGUSR1 to communicate with threads (even if you aren't using more that one thread in your code). it doesn't on windows though (there are no signals there ;- ), but your posix code can accidentally block/intercept the signals druntime uses for internal bookkeeping.

On Wednesday, 18 February 2015 at 20:55:56 UTC, ketmar wrote: > On Wed, 18 Feb 2015 20:35:44 +0000, Byron Heads wrote: > >> On Wednesday, 18 February 2015 at 20:33:40 UTC, ketmar wrote: >>> On Wed, 18 Feb 2015 20:27:07 +0000, Byron Heads wrote: >>> >>> are you forking? ;-) >> >> >> I am in the daemonize library >> >> https://github.com/NCrashed/daemonize > > can you drop that and just let the program run on foreground? i suspect > that it may solve your problem. you can detach your program with "setsid" > and "&" to avoid forking. > > `fork()` is a very fragile thing, and it may be the source of heisenbugs. > stop `fork()`ing may be the easiest solution (if it solves something, of > course ;-). By passing daemonize with the GC enabled is working.. going to dig into the signals and see if thats it.

On Wednesday, 18 February 2015 at 21:05:10 UTC, Byron Heads wrote: > On Wednesday, 18 February 2015 at 20:55:56 UTC, ketmar wrote: >> On Wed, 18 Feb 2015 20:35:44 +0000, Byron Heads wrote: >> >>> On Wednesday, 18 February 2015 at 20:33:40 UTC, ketmar wrote: >>>> On Wed, 18 Feb 2015 20:27:07 +0000, Byron Heads wrote: >>>> >>>> are you forking? ;-) >>> >>> >>> I am in the daemonize library >>> >>> https://github.com/NCrashed/daemonize >> >> can you drop that and just let the program run on foreground? i suspect >> that it may solve your problem. you can detach your program with "setsid" >> and "&" to avoid forking. >> >> `fork()` is a very fragile thing, and it may be the source of heisenbugs. >> stop `fork()`ing may be the easiest solution (if it solves something, of >> course ;-). > > By passing daemonize with the GC enabled is working.. going to dig into the signals and see if thats it. My guess is this is going to be related to forking, going to see if I can make a test case.

On Wednesday, 18 February 2015 at 21:21:11 UTC, Byron Heads wrote: > On Wednesday, 18 February 2015 at 21:05:10 UTC, Byron Heads wrote: >> On Wednesday, 18 February 2015 at 20:55:56 UTC, ketmar wrote: >>> On Wed, 18 Feb 2015 20:35:44 +0000, Byron Heads wrote: >>> >>>> On Wednesday, 18 February 2015 at 20:33:40 UTC, ketmar wrote: >>>>> On Wed, 18 Feb 2015 20:27:07 +0000, Byron Heads wrote: >>>>> >>>>> are you forking? ;-) >>>> >>>> >>>> I am in the daemonize library >>>> >>>> https://github.com/NCrashed/daemonize >>> >>> can you drop that and just let the program run on foreground? i suspect >>> that it may solve your problem. you can detach your program with "setsid" >>> and "&" to avoid forking. >>> >>> `fork()` is a very fragile thing, and it may be the source of heisenbugs. >>> stop `fork()`ing may be the easiest solution (if it solves something, of >>> course ;-). >> >> By passing daemonize with the GC enabled is working.. going to dig into the signals and see if thats it. > > > > My guess is this is going to be related to forking, going to see if I can make a test case. Might be related: https://issues.dlang.org/show_bug.cgi?id=6846

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