diff options
author | normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2015-12-29 18:20:27 +0000 |
---|---|---|
committer | normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2015-12-29 18:20:27 +0000 |
commit | 24c979bdeaa8883a6d24139190ba5a4fc970e190 (patch) | |
tree | eaadfc199a9c6d96066e9710d0ab1823463098df /thread_pthread.c | |
parent | 290deeb7052f54b2bf7adb520c0601b578524580 (diff) | |
download | ruby-24c979bdeaa8883a6d24139190ba5a4fc970e190.tar.gz |
thread_pthread.c (rb_thread_create_timer_thread): fix race
This fixes an occasional [ASYNC BUG] failure in
bootstraptest/test_fork.rb '[ruby-dev:37934]'
which tests fork/pthread_create failure by setting
RLIMIT_NPROC to 1 and triggering EAGAIN on pthread_create
when attempting to recreate the timer thread.
The problem timeline is as follows:
thread 1 thread 2
---------------------------------------------------------------
rb_thread_create_timer_thread
setup_communication_pipe
rb_thread_wakeup_timer_thread_low
pthread_create fails pipe looks valid, write!
CLOSE_INVALIDATE (x4) EBADF -> ASYNC BUG
The checks in rb_thread_wakeup_timer_thread_low only tried to
guarantee proper ordering with native_stop_timer_thread, not
rb_thread_create_timer_thread :x
Now, this should allow rb_thread_create_timer_thread to
synchronize properly with rb_thread_wakeup_timer_thread_low by
delaying the validation marking of the timer_thread_pipe until
we are certain the timer thread is alive.
In this version, rb_thread_wakeup_timer_thread_low becomes a
noop. Threading is still completely broken with NPROC==1, but
there's not much we can do about it beside warn the user.
We no longer spew a scary [ASYNC BUG] message or dump core
on them.
* thread_pthread.c (setup_communication_pipe): delay setting owner
(rb_thread_create_timer_thread): until thread creation succeeds
[ruby-core:72590] [Bug #11922]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53373 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'thread_pthread.c')
-rw-r--r-- | thread_pthread.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/thread_pthread.c b/thread_pthread.c index 2a15816713..46cc5715c4 100644 --- a/thread_pthread.c +++ b/thread_pthread.c @@ -1406,8 +1406,6 @@ setup_communication_pipe(void) return e; } - /* validate pipe on this process */ - timer_thread_pipe.owner_process = getpid(); return 0; } @@ -1615,6 +1613,9 @@ rb_thread_create_timer_thread(void) #endif return; } + + /* validate pipe on this process */ + timer_thread_pipe.owner_process = getpid(); timer_thread.created = 1; #ifdef HAVE_PTHREAD_ATTR_INIT pthread_attr_destroy(&attr); |