Bug ID 24958
Summary lldb::SBDebugger::Terminate() results in Deadlock
Product lldb
Version unspecified
Hardware PC
OS Linux
Status NEW
Severity normal
Priority P
Component All Bugs
Assignee lldb-dev@lists.llvm.org
Reporter kratochwil@teco.edu
CC llvm-bugs@lists.llvm.org
Classification Unclassified
Created attachment 14945 [details]
Complete debug log, backtrace is at the end. The questionable mutex is
0x7ffff7dc2fc0.
While using the C++ API (Scripting Bridge) of lldb (svn revision 247535), the
following (abbreviated) call sequence results in a Deadlock:
lldb_debugger = lldb::SBDebugger::Create()
lldb_debugger.SetAsync(true)
lldb_target = lldb_debugger.CreateTarget()
lldb_process = lldb_target.AttachToProcessWithID()
... (doing stuff with modules)
lldb::SBDebugger::Terminate()
I compiled Mutex.cpp with both debug macros DEBUG_LOG and
ENABLE_MUTEX_ERROR_CHECKING enabled - the latter results in my program
receiving a SIGABRT instead of a deadlock, due to the mutex error checking
code.
I noticed that the call to lldb_private::Debugger::Terminate() ends up in
lldb_private::Mutex::Lock(). Here a mutex is being locked which was already
locked / unlocked a few times earlier (see attachment: the mutex has the ID
0x7ffff7dc2fc0).
I know that my code worked with svn revision 229496 (tested it a few hours
ago).
The debug log is quite lengthy - sorry for that. At the bottom you'll find a
complete gdb backtrace.
I'll recompile lldb without the error checking macros to see if there is more
than one thread running when the deadlock occurs. I'll be back in a minute...