Add a new SBThread::SafeToCallFunctions API; this calls over to

the SystemRuntime to check if a thread will have any problems 
performing an inferior function call so the driver can skip
making that function call on that thread.  Often the function
call can be executed on another thread instead.
<rdar://problem/16777874> 

llvm-svn: 208732

1 files changed, 15 insertions, 0 deletions

diff --git a/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp b/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp
index 7ff14fc5e09..f3f1fa31cd7 100644
--- a/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp
+++ b/lldb/source/Plugins/SystemRuntime/MacOSX/SystemRuntimeMacOSX.cpp
@@ -214,6 +214,21 @@ SystemRuntimeMacOSX::GetQueueKind (addr_t dispatch_queue_addr)
     return kind;
 }
 
+bool
+SystemRuntimeMacOSX::SafeToCallFunctionsOnThisThread (ThreadSP thread_sp)
+{
+    if (thread_sp && thread_sp->GetStackFrameCount() > 0 && thread_sp->GetFrameWithConcreteFrameIndex(0))
+    {
+        const SymbolContext sym_ctx (thread_sp->GetFrameWithConcreteFrameIndex(0)->GetSymbolContext (eSymbolContextSymbol));
+        static ConstString g_select_symbol ("__select");
+        if (sym_ctx.GetFunctionName() == g_select_symbol)
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
 lldb::queue_id_t
 SystemRuntimeMacOSX::GetQueueIDFromThreadQAddress (lldb::addr_t dispatch_qaddr)
 {