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Fix a race on process exit 

Summary:
Process::SetExitStatus was popping the process io handler and resetting m_process_input_reader
shared pointer, which is not a safe thing to do as the function is called asynchronously and
other threads may be accessing the member variable. (E.g. if the process terminates really
quickly, the private state thread might only be in the process of pushing the handler on the
stack. Sometimes, this leads to deadlock, as the shared pointer's state gets corrupted by the
concurrent access.

Since the IOHandler will be popped anyway in Process:HandleProcessStateChangedEvent when the
exited event gets processed, doing the same in SetExitStatus seems to be unnecessary.

Reviewers: clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D22209

llvm-svn: 275165
This commit is contained in:
Pavel Labath 2016-07-12 09:37:55 +00:00
parent 402c8c0716
commit dc15f1d7b8
1 changed files with 0 additions and 8 deletions
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8
lldb/source/Target/Process.cpp
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@ -1462,14 +1462,6 @@ Process::SetExitStatus (int status, const char *cstr)
else else
m_exit_string.clear(); m_exit_string.clear();
// When we exit, we don't need the input reader anymore
if (m_process_input_reader)
{
m_process_input_reader->SetIsDone(true);
m_process_input_reader->Cancel();
m_process_input_reader.reset();
}
// Clear the last natural stop ID since it has a strong // Clear the last natural stop ID since it has a strong
// reference to this process // reference to this process
m_mod_id.SetStopEventForLastNaturalStopID(EventSP()); m_mod_id.SetStopEventForLastNaturalStopID(EventSP());