tree 77f0a0272a5a53a03771438d1f671ce374701bcd
parent a224c7c673a433ef9f6673929a5eb8508bd8e73d
author Daniel Malea <daniel.malea@intel.com> 1375302080 +0000
committer Daniel Malea <daniel.malea@intel.com> 1375302080 +0000

Fix lock hierarchy violation in Process (lock ordering of ThreadList mutex and StackFrameList mutex)
- this fix ensures the ThreadList mutex is always locked before the StackFrameList mutex

Situation where deadlock could occur (without this fix):
Thread 1 is in Process::WillResume and locks the ThreadList mutex (on entry), and subsequently calls StackFrameList::Clear() which locks the StackFrameList mutex.
Meanwhile, thread 2 is in Process::RunThreadPlan and calls Thread::SetSelectedFrame() (which locks the StackFrameList mutex) before calling GetSelectedThread (which attempts to lock the ThreadList mutex)

In my testing on both Linux and Mac OS X, I was unable to reproduce any hangs with this patch applied.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@187522 91177308-0d34-0410-b5e6-96231b3b80d8