<rdar://problem/11035349>
Fixed an issue with stepping where the stack frame list could get changed out from underneath you when multiple threads start accessing frame info.
llvm-svn: 153627
diff --git a/lldb/include/lldb/Target/Thread.h b/lldb/include/lldb/Target/Thread.h
index c03d298..172a9f2 100644
--- a/lldb/include/lldb/Target/Thread.h
+++ b/lldb/include/lldb/Target/Thread.h
@@ -320,13 +320,13 @@
virtual uint32_t
GetStackFrameCount()
{
- return GetStackFrameList().GetNumFrames();
+ return GetStackFrameList()->GetNumFrames();
}
virtual lldb::StackFrameSP
GetStackFrameAtIndex (uint32_t idx)
{
- return GetStackFrameList().GetFrameAtIndex(idx);
+ return GetStackFrameList()->GetFrameAtIndex(idx);
}
virtual lldb::StackFrameSP
@@ -335,37 +335,38 @@
virtual lldb::StackFrameSP
GetFrameWithStackID (const StackID &stack_id)
{
- return GetStackFrameList().GetFrameWithStackID (stack_id);
+ return GetStackFrameList()->GetFrameWithStackID (stack_id);
}
uint32_t
GetSelectedFrameIndex ()
{
- return GetStackFrameList().GetSelectedFrameIndex();
+ return GetStackFrameList()->GetSelectedFrameIndex();
}
lldb::StackFrameSP
GetSelectedFrame ()
{
- return GetStackFrameAtIndex (GetStackFrameList().GetSelectedFrameIndex());
+ lldb::StackFrameListSP stack_frame_list_sp(GetStackFrameList());
+ return stack_frame_list_sp->GetFrameAtIndex (stack_frame_list_sp->GetSelectedFrameIndex());
}
uint32_t
SetSelectedFrame (lldb_private::StackFrame *frame)
{
- return GetStackFrameList().SetSelectedFrame(frame);
+ return GetStackFrameList()->SetSelectedFrame(frame);
}
bool
SetSelectedFrameByIndex (uint32_t frame_idx)
{
- return GetStackFrameList().SetSelectedFrameByIndex(frame_idx);
+ return GetStackFrameList()->SetSelectedFrameByIndex(frame_idx);
}
void
SetDefaultFileAndLineToSelectedFrame()
{
- GetStackFrameList().SetDefaultFileAndLineToSelectedFrame();
+ GetStackFrameList()->SetDefaultFileAndLineToSelectedFrame();
}
virtual lldb::RegisterContextSP
@@ -798,7 +799,7 @@
virtual lldb_private::Unwind *
GetUnwinder ();
- StackFrameList &
+ lldb::StackFrameListSP
GetStackFrameList ();
lldb::StateType GetTemporaryResumeState()
@@ -832,6 +833,7 @@
plan_stack m_plan_stack; ///< The stack of plans this thread is executing.
plan_stack m_completed_plan_stack; ///< Plans that have been completed by this stop. They get deleted when the thread resumes.
plan_stack m_discarded_plan_stack; ///< Plans that have been discarded by this stop. They get deleted when the thread resumes.
+ mutable Mutex m_frame_mutex; ///< Multithreaded protection for m_state.
lldb::StackFrameListSP m_curr_frames_sp; ///< The stack frames that get lazily populated after a thread stops.
lldb::StackFrameListSP m_prev_frames_sp; ///< The previous stack frames from the last time this thread stopped.
int m_resume_signal; ///< The signal that should be used when continuing this thread.
diff --git a/lldb/source/Target/Thread.cpp b/lldb/source/Target/Thread.cpp
index 1000b69..6a86a3b 100644
--- a/lldb/source/Target/Thread.cpp
+++ b/lldb/source/Target/Thread.cpp
@@ -54,6 +54,7 @@
m_state_mutex (Mutex::eMutexTypeRecursive),
m_plan_stack (),
m_completed_plan_stack(),
+ m_frame_mutex (Mutex::eMutexTypeRecursive),
m_curr_frames_sp (),
m_prev_frames_sp (),
m_resume_signal (LLDB_INVALID_SIGNAL_NUMBER),
@@ -1058,17 +1059,28 @@
}
-StackFrameList &
+StackFrameListSP
Thread::GetStackFrameList ()
{
- if (!m_curr_frames_sp)
- m_curr_frames_sp.reset (new StackFrameList (*this, m_prev_frames_sp, true));
- return *m_curr_frames_sp;
+ StackFrameListSP frame_list_sp;
+ Mutex::Locker locker(m_frame_mutex);
+ if (m_curr_frames_sp)
+ {
+ frame_list_sp = m_curr_frames_sp;
+ }
+ else
+ {
+ frame_list_sp.reset(new StackFrameList (*this, m_prev_frames_sp, true));
+ m_curr_frames_sp = frame_list_sp;
+ }
+ return frame_list_sp;
}
void
Thread::ClearStackFrames ()
{
+ Mutex::Locker locker(m_frame_mutex);
+
// Only store away the old "reference" StackFrameList if we got all its frames:
// FIXME: At some point we can try to splice in the frames we have fetched into
// the new frame as we make it, but let's not try that now.
@@ -1080,7 +1092,7 @@
lldb::StackFrameSP
Thread::GetFrameWithConcreteFrameIndex (uint32_t unwind_idx)
{
- return GetStackFrameList().GetFrameWithConcreteFrameIndex (unwind_idx);
+ return GetStackFrameList()->GetFrameWithConcreteFrameIndex (unwind_idx);
}
void
@@ -1176,7 +1188,7 @@
lldb::StackFrameSP
Thread::GetStackFrameSPForStackFramePtr (StackFrame *stack_frame_ptr)
{
- return GetStackFrameList().GetStackFrameSPForStackFramePtr (stack_frame_ptr);
+ return GetStackFrameList()->GetStackFrameSPForStackFramePtr (stack_frame_ptr);
}
const char *
@@ -1253,13 +1265,13 @@
const uint32_t source_lines_before = 3;
const uint32_t source_lines_after = 3;
strm.IndentMore ();
- num_frames_shown = GetStackFrameList ().GetStatus (strm,
- start_frame,
- num_frames,
- show_frame_info,
- num_frames_with_source,
- source_lines_before,
- source_lines_after);
+ num_frames_shown = GetStackFrameList ()->GetStatus (strm,
+ start_frame,
+ num_frames,
+ show_frame_info,
+ num_frames_with_source,
+ source_lines_before,
+ source_lines_after);
strm.IndentLess();
strm.IndentLess();
}
@@ -1275,13 +1287,13 @@
uint32_t source_lines_before,
uint32_t source_lines_after)
{
- return GetStackFrameList().GetStatus (strm,
- first_frame,
- num_frames,
- show_frame_info,
- num_frames_with_source,
- source_lines_before,
- source_lines_after);
+ return GetStackFrameList()->GetStatus (strm,
+ first_frame,
+ num_frames,
+ show_frame_info,
+ num_frames_with_source,
+ source_lines_before,
+ source_lines_after);
}
bool