Assertion when upstream connection is established (with event handled by thread
A) and immediately disconnected (handled by thread B)
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Key: TS-1032
URL: https://issues.apache.org/jira/browse/TS-1032
Project: Traffic Server
Issue Type: Bug
Components: Core, HTTP
Affects Versions: 3.1.1
Environment: Linux 32bit CentOS 5.4. Pre-open source version of ATS.
Reporter: Uri Shachar
This happened twice on a very old version of ATS (pre opensource code), but it
looks like it can happen in current ATS as well (it's a very rare race
condition, haven't been able to reproduce).
Scenario:
1) Client request arrives, handled by TS thread 1 and is reenabled
by a plugin (Inside a continuation called by ContSched)
2) TS thread 2 starts to connect upstream
3) A client disconnection event is placed in thread 1 queue.
4) A successful connection event is placed in thread 2 queue.
5) Thread 1 starts to handle pending events (setting cur_time to X)
6) Thread 2 starts to handle pending events (setting cur_time to
Z=X+Y)
7) Thread 2 handles the connection established event (setting
server_first_connect to Z)
8) Thread 1 handles the client disconnection event - Getting a
negative wait and asserting...
Sample stack trace:
Program received signal SIGABRT, Aborted.
[Switching to Thread 0xe3131b90 (LWP 14584)]
0xffffe410 in __kernel_vsyscall ()
#0 0xffffe410 in __kernel_vsyscall ()
#1 0x007e2df0 in raise () from /lib/libc.so.6
#2 0x007e484e in abort () from /lib/libc.so.6
#3 0x08427612 in ink_die_die_die (retval=1) at
/usr/src/debug/wts/proxy/ts/traffic/libwebsense++/ink_error.cc:45
#4 0x08427778 in ink_fatal_va (return_code=1, message_format=0xe312ee1f
"/tmp/ushachar-rpmbuild/BUILD/wts/proxy/ts/traffic/proxy/http2/HttpSM.cc:5572:
failed assert `wait >= 0`", ap=0xe312ee08 "\002") at
/usr/src/debug/wts/proxy/ts/traffic/libwebsense++/ink_error.cc:100
#5 0x084277d3 in ink_fatal (return_code=1, message_format=0xe312ee1f
"/tmp/ushachar-rpmbuild/BUILD/wts/proxy/ts/traffic/proxy/http2/HttpSM.cc:5572:
failed assert `wait >= 0`") at
/usr/src/debug/wts/proxy/ts/traffic/libwebsense++/ink_error.cc:111
#6 0x08424508 in _ink_assert (a=0x853db72 "wait >= 0", f=0x853ab3c
"/tmp/ushachar-rpmbuild/BUILD/wts/proxy/ts/traffic/proxy/http2/HttpSM.cc",
l=5572) at /usr/src/debug/wts/proxy/ts/traffic/libwebsense++/ink_assert.cc:27
#7 0x082f2505 in HttpSM::mark_server_down_on_client_abort (this=0xb622ece0) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/http2/HttpSM.cc:5572
#8 0x082f6080 in HttpSM::state_watch_for_client_abort (this=0xb622ece0,
event=3, data=0x7e0e2a88) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/http2/HttpSM.cc:1148
#9 0x082fad0f in HttpSM::main_handler (this=0xb622ece0, event=3,
data=0x7e0e2a88) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/http2/HttpSM.cc:3213
#10 0x0810a07b in Continuation::handleEvent (this=0xb622ece0, event=3,
data=0x7e0e2a88) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/Continuation.h:85
#11 0x083ab348 in read_signal_and_update (event=3, vc=0x7e0e2a30) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixNet.cc:262
#12 0x083ab3fe in read_signal_done (event=3, nh=0xa339b28, vc=0x7e0e2a30) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixNet.cc:300
#13 0x083ab44f in read_signal_error (nh=0xa339b28, vc=0x7e0e2a30, lerrno=104)
at /usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixNet.cc:324
#14 0x083ae1c5 in read_from_net (nh=0xa339b28, vc=0x7e0e2a30, thread=0xa32e490)
at /usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixNet.cc:783
#15 0x083ae5a7 in UnixNetVConnection::net_read_io (this=0x7e0e2a30,
nh=0xa339b28, lthread=0xa32e490) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixNet.cc:1059
#16 0x083adced in NetHandler::mainNetEvent (this=0xa339b28, event=5,
e=0xa1ab810) at /usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixNet.cc:1272
#17 0x0810a07b in Continuation::handleEvent (this=0xa339b28, event=5,
data=0xa1ab810) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/Continuation.h:85
#18 0x083a19ac in EThread::process_event (this=0xa32e490, e=0xa1ab810,
calling_code=5) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixEThread.cc:132
#19 0x0839f800 in EThread::execute (this=0xa32e490) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixEThread.cc:315
#20 0x083b4f9a in spawn_thread_internal (a=0xa385360) at
/usr/src/debug/wts/proxy/ts/traffic/proxy/iocore/UnixThread.cc:71
#21 0x009065ab in start_thread () from /lib/libpthread.so.0
#22 0x0088bcfe in clone () from /lib/libc.so.6
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