Rework how the API mutex is acquired when filling out an ExecutionContext from an ExecutionContextRef,

particularly in the SBThread & SBFrame interfaces.  Instead of filling the whole context & then getting
the API mutex, we now get only the target, acquire the API mutex from it, then fill out the rest of the
context.  This removes a race condition where you get a ThreadSP, then wait on the API mutex while another
command Destroy's the Thread you've just gotten.
Also fixed the ExecutionContextRef::Get*SP calls so they don't return invalid objects.
Also fixed the ExecutionContext::Has*Scope calls so they don't claim to have a scope if the object representing
that scope has been destroyed.
Also fixed a think-o in Thread::IsValid which was causing it to return the opposite of the desired value.

<rdar://problem/11995490>

llvm-svn: 162401

1 files changed, 2 insertions, 0 deletions

diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index 29f3793c360..454cf3a51e6 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -921,6 +921,7 @@ Process::Process(Target &target, Listener &listener) :
     m_next_event_action_ap(),
     m_run_lock (),
     m_currently_handling_event(false),
+    m_finalize_called(false),
     m_can_jit(eCanJITDontKnow)
 {
     CheckInWithManager ();
@@ -1016,6 +1017,7 @@ Process::Finalize()
     m_allocated_memory_cache.Clear();
     m_language_runtimes.clear();
     m_next_event_action_ap.reset();
+    m_finalize_called = true;
 }
 
 void