From 5bf72c46b33c0058b4147fd6bbda4b53322f67ca Mon Sep 17 00:00:00 2001 From: Hafiz Abid Qadeer Date: Wed, 11 Feb 2015 16:37:17 +0000 Subject: [PATCH] Lock mutex in the same order. SBProcess uses 2 mutexex; RunLock and APILock. Apart from 2 places, RunLock is locked before API lock. I have fixed the 2 places where order was different. I observed a deadlock due to this different order in lldb-mi once. Although lldb-mi command and event thread dont run at the same time now. So it can not deadlock there but can still be problem for some other clients. Pre-approved by Greg in http://lists.cs.uiuc.edu/pipermail/lldb-dev/2015-February/006509.html llvm-svn: 228844 --- lldb/source/API/SBProcess.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lldb/source/API/SBProcess.cpp b/lldb/source/API/SBProcess.cpp index 9a0b23b..5de36e3 100644 --- a/lldb/source/API/SBProcess.cpp +++ b/lldb/source/API/SBProcess.cpp @@ -918,9 +918,9 @@ SBProcess::GetThreadByID (tid_t tid) ProcessSP process_sp(GetSP()); if (process_sp) { - Mutex::Locker api_locker (process_sp->GetTarget().GetAPIMutex()); Process::StopLocker stop_locker; const bool can_update = stop_locker.TryLock(&process_sp->GetRunLock()); + Mutex::Locker api_locker (process_sp->GetTarget().GetAPIMutex()); thread_sp = process_sp->GetThreadList().FindThreadByID (tid, can_update); sb_thread.SetThread (thread_sp); } @@ -942,9 +942,9 @@ SBProcess::GetThreadByIndexID (uint32_t index_id) ProcessSP process_sp(GetSP()); if (process_sp) { - Mutex::Locker api_locker (process_sp->GetTarget().GetAPIMutex()); Process::StopLocker stop_locker; const bool can_update = stop_locker.TryLock(&process_sp->GetRunLock()); + Mutex::Locker api_locker (process_sp->GetTarget().GetAPIMutex()); thread_sp = process_sp->GetThreadList().FindThreadByIndexID (index_id, can_update); sb_thread.SetThread (thread_sp); } -- 2.7.4