Thread hardening part 3. Now lldb_private::Thread objects have std::weak_ptr

objects for the backlink to the lldb_private::Process. The issues we were
running into before was someone was holding onto a shared pointer to a 
lldb_private::Thread for too long, and the lldb_private::Process parent object
would get destroyed and the lldb_private::Thread had a "Process &m_process"
member which would just treat whatever memory that used to be a Process as a
valid Process. This was mostly happening for lldb_private::StackFrame objects
that had a member like "Thread &m_thread". So this completes the internal
strong/weak changes.

Documented the ExecutionContext and ExecutionContextRef classes so that our
LLDB developers can understand when and where to use ExecutionContext and 
ExecutionContextRef objects.

llvm-svn: 151009

1 files changed, 16 insertions, 8 deletions

diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextMemory.cpp b/lldb/source/Plugins/Process/Utility/RegisterContextMemory.cpp
index ff077b4d6407..03610a2fe7cd 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextMemory.cpp
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextMemory.cpp
@@ -134,11 +134,15 @@ RegisterContextMemory::ReadAllRegisterValues (DataBufferSP &data_sp)
 {
     if (m_reg_data_addr != LLDB_INVALID_ADDRESS)
     {
-        Error error;
-        if (m_thread.GetProcess().ReadMemory(m_reg_data_addr, data_sp->GetBytes(), data_sp->GetByteSize(), error) == data_sp->GetByteSize())
+        ProcessSP process_sp (CalculateProcess());
+        if (process_sp)
         {
-            SetAllRegisterValid (true);
-            return true;
+            Error error;
+            if (process_sp->ReadMemory(m_reg_data_addr, data_sp->GetBytes(), data_sp->GetByteSize(), error) == data_sp->GetByteSize())
+            {
+                SetAllRegisterValid (true);
+                return true;
+            }
         }
     }
     return false;
@@ -149,10 +153,14 @@ RegisterContextMemory::WriteAllRegisterValues (const DataBufferSP &data_sp)
 {
     if (m_reg_data_addr != LLDB_INVALID_ADDRESS)
     {
-        Error error;
-        SetAllRegisterValid (false);
-        if (m_thread.GetProcess().WriteMemory(m_reg_data_addr, data_sp->GetBytes(), data_sp->GetByteSize(), error) == data_sp->GetByteSize())
-            return true;
+        ProcessSP process_sp (CalculateProcess());
+        if (process_sp)
+        {
+            Error error;
+            SetAllRegisterValid (false);
+            if (process_sp->WriteMemory(m_reg_data_addr, data_sp->GetBytes(), data_sp->GetByteSize(), error) == data_sp->GetByteSize())
+                return true;
+        }
     }
     return false;
 }