use std::atomic<> to protect variables being accessed by multiple threads

There are several places where multiple threads are accessing the same variables simultaneously without any kind of protection. I propose using std::atomic<> to make it safer. I did a special build of lldb, using the google tool 'thread sanitizer' which identified many cases of multiple threads accessing the same memory. std::atomic is low overhead and does not use any locks for simple types such as int/bool.

See http://reviews.llvm.org/D5302 for more details.

Change by Shawn Best.

llvm-svn: 217818

1 files changed, 1 insertions, 1 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
index 5e1365c..d9388d5 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
@@ -328,7 +328,7 @@ protected:
     
     lldb_private::Flags m_flags;            // Process specific flags (see eFlags enums)
     GDBRemoteCommunicationClient m_gdb_comm;
-    lldb::pid_t m_debugserver_pid;
+    std::atomic<lldb::pid_t> m_debugserver_pid;
     StringExtractorGDBRemote m_last_stop_packet;
     lldb_private::Mutex m_last_stop_packet_mutex;
     GDBRemoteDynamicRegisterInfo m_register_info;