Index: lldb/trunk/tools/driver/Driver.cpp
===================================================================
--- lldb/trunk/tools/driver/Driver.cpp
+++ lldb/trunk/tools/driver/Driver.cpp
@@ -9,6 +9,7 @@
 
 #include "Driver.h"
 
+#include <atomic>
 #include <csignal>
 #include <fcntl.h>
 #include <limits.h>
@@ -1177,17 +1178,16 @@
 }
 
 void sigint_handler(int signo) {
-  static bool g_interrupt_sent = false;
+  static std::atomic_flag g_interrupt_sent = ATOMIC_FLAG_INIT;
   if (g_driver) {
-    if (!g_interrupt_sent) {
-      g_interrupt_sent = true;
+    if (!g_interrupt_sent.test_and_set()) {
       g_driver->GetDebugger().DispatchInputInterrupt();
-      g_interrupt_sent = false;
+      g_interrupt_sent.clear();
       return;
     }
   }
 
-  exit(signo);
+  _exit(signo);
 }
 
 void sigtstp_handler(int signo) {
Index: lldb/trunk/tools/lldb-mi/MIDriverMain.cpp
===================================================================
--- lldb/trunk/tools/lldb-mi/MIDriverMain.cpp
+++ lldb/trunk/tools/lldb-mi/MIDriverMain.cpp
@@ -33,6 +33,7 @@
 
 // Third party headers:
 #include "lldb/API/SBHostOS.h"
+#include <atomic>
 #include <csignal>
 #include <stdio.h>
 
@@ -72,14 +73,13 @@
 #ifdef _WIN32 // Restore handler as it is not persistent on Windows
   signal(SIGINT, sigint_handler);
 #endif
-  static bool g_interrupt_sent = false;
+  static std::atomic_flag g_interrupt_sent = ATOMIC_FLAG_INIT;
   CMIDriverMgr &rDriverMgr = CMIDriverMgr::Instance();
   lldb::SBDebugger *pDebugger = rDriverMgr.DriverGetTheDebugger();
   if (pDebugger != nullptr) {
-    if (!g_interrupt_sent) {
-      g_interrupt_sent = true;
+    if (!g_interrupt_sent.test_and_set()) {
       pDebugger->DispatchInputInterrupt();
-      g_interrupt_sent = false;
+      g_interrupt_sent.clear();
     }
   }