Add a lock ivar to the Platform so that multiple Targets

trying to populate the list of trap handler names at
the same time don't conflict with one another.
<rdar://problem/17011969> 

llvm-svn: 209563

2 files changed, 9 insertions, 3 deletions

diff --git a/lldb/include/lldb/Target/Platform.h b/lldb/include/lldb/Target/Platform.h
index 80011fd120d..e1e1c91d6fe 100644
--- a/lldb/include/lldb/Target/Platform.h
+++ b/lldb/include/lldb/Target/Platform.h
@@ -892,6 +892,7 @@ namespace lldb_private {
         std::string m_local_cache_directory;
         std::vector<ConstString> m_trap_handlers;
         bool m_calculated_trap_handlers;
+        Mutex m_trap_handler_mutex;
 
         //------------------------------------------------------------------
         /// Ask the Platform subclass to fill in the list of trap handler names
diff --git a/lldb/source/Target/Platform.cpp b/lldb/source/Target/Platform.cpp
index d1e5cebc685..96f63ead89c 100644
--- a/lldb/source/Target/Platform.cpp
+++ b/lldb/source/Target/Platform.cpp
@@ -257,7 +257,8 @@ Platform::Platform (bool is_host) :
     m_ssh_opts (),
     m_ignores_remote_hostname (false),
     m_trap_handlers(),
-    m_calculated_trap_handlers (false)
+    m_calculated_trap_handlers (false),
+    m_trap_handler_mutex()
 {
     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT));
     if (log)
@@ -1398,8 +1399,12 @@ Platform::GetTrapHandlerSymbolNames ()
 {
     if (!m_calculated_trap_handlers)
     {
-        CalculateTrapHandlerSymbolNames();
-        m_calculated_trap_handlers = true;
+        Mutex::Locker locker (m_trap_handler_mutex);
+        if (!m_calculated_trap_handlers)
+        {
+            CalculateTrapHandlerSymbolNames();
+            m_calculated_trap_handlers = true;
+        }
     }
     return m_trap_handlers;
 }