[
https://issues.apache.org/jira/browse/TS-937?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13097644#comment-13097644
]
Brian Geffon commented on TS-937:
---------------------------------
Thanks for the response weijin. Perhaps I'm missing something but there is
currently a check for the event being cancelled in ProcessEvent for all events
that do not have a timeout, if the event has some timeout on it then there
won't be a check, why would it be safe to put the cancel check in ProcessEvent
in that situation?
[http://svn.apache.org/viewvc/trafficserver/traffic/trunk/iocore/eventsystem/UnixEThread.cc?view=markup#l234]
> EThread::execute still processing cancelled event
> -------------------------------------------------
>
> Key: TS-937
> URL: https://issues.apache.org/jira/browse/TS-937
> Project: Traffic Server
> Issue Type: Bug
> Components: Core
> Affects Versions: 3.0.1, 2.1.9
> Environment: RHEL6
> Reporter: Brian Geffon
> Fix For: 3.1.1
>
> Attachments: UnixEThread.patch
>
>
> The included GDB log will show that ATS is trying to process an event that
> has already been canceled, examining the code of UnixEThread.cc line 232
> shows that EThread::process_event gets called without a check for the event
> being cancelled.
> Brian
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 0x7ffff64fa700 (LWP 28518)]
> 0x00000000006fc663 in EThread::process_event (this=0x7ffff68ff010,
> e=0x1db45c0, calling_code=1) at UnixEThread.cc:130
> 130 MUTEX_TRY_LOCK_FOR(lock, e->mutex.m_ptr, this, e->continuation);
> Missing separate debuginfos, use: debuginfo-install
> expat-2.0.1-9.1.el6.x86_64 glibc-2.12-1.25.el6_1.3.x86_64
> keyutils-libs-1.4-1.el6.x86_64 krb5-libs-1.9-9.el6_1.1.x86_64
> libcom_err-1.41.12-7.el6.x86_64 libgcc-4.4.5-6.el6.x86_64
> libselinux-2.0.94-5.el6.x86_64 libstdc++-4.4.5-6.el6.x86_64
> openssl-1.0.0-10.el6_1.4.x86_64 pcre-7.8-3.1.el6.x86_64
> tcl-8.5.7-6.el6.x86_64 zlib-1.2.3-25.el6.x86_64
> (gdb) bt
> #0 0x00000000006fc663 in EThread::process_event (this=0x7ffff68ff010,
> e=0x1db45c0, calling_code=1) at UnixEThread.cc:130
> #1 0x00000000006fcbaf in EThread::execute (this=0x7ffff68ff010) at
> UnixEThread.cc:232
> #2 0x00000000006fb844 in spawn_thread_internal (a=0xfb7e80) at Thread.cc:88
> #3 0x00000036204077e1 in start_thread () from /lib64/libpthread.so.0
> #4 0x000000361f8e577d in clone () from /lib64/libc.so.6
> (gdb) bt full
> #0 0x00000000006fc663 in EThread::process_event (this=0x7ffff68ff010,
> e=0x1db45c0, calling_code=1) at UnixEThread.cc:130
> lock = {m = {m_ptr = 0x7ffff64f9d20}, lock_acquired = 202}
> #1 0x00000000006fcbaf in EThread::execute (this=0x7ffff68ff010) at
> UnixEThread.cc:232
> done_one = false
> e = 0x1db45c0
> NegativeQueue = {<DLL<Event, Event::Link_link>> = {head = 0xfc75f0},
> tail = 0xfc75f0}
> next_time = 1314647904419648000
> #2 0x00000000006fb844 in spawn_thread_internal (a=0xfb7e80) at Thread.cc:88
> p = 0xfb7e80
> #3 0x00000036204077e1 in start_thread () from /lib64/libpthread.so.0
> No symbol table info available.
> #4 0x000000361f8e577d in clone () from /lib64/libc.so.6
> No symbol table info available.
> (gdb) f 0
> #0 0x00000000006fc663 in EThread::process_event (this=0x7ffff68ff010,
> e=0x1db45c0, calling_code=1) at UnixEThread.cc:130
> 130 MUTEX_TRY_LOCK_FOR(lock, e->mutex.m_ptr, this, e->continuation);
> (gdb) p *e
> $2 = {<Action> = {_vptr.Action = 0x775170, continuation = 0x1f2fc08, mutex =
> {m_ptr = 0x7fffd40fba40}, cancelled = 1}, ethread = 0x7ffff68ff010,
> in_the_prot_queue = 0, in_the_priority_queue = 0,
> immediate = 1, globally_allocated = 1, in_heap = 0, callback_event = 1,
> timeout_at = 0, period = 0, cookie = 0x0, link = {<SLink<Event>> = {next =
> 0x0}, prev = 0x0}}
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
