coverity#1441101: Use std::atomic instead of volatile

ee9ccdf6 "reduce cost of ProfileZone when it is
not active" had changed g_bRecording from a bool guarded by g_aMutex to a
volatile bool.  But having been guarded by a mutex indicates that g_bRecording
is potentially accessed from multiple threads, and volatile does not avoid
races.

Change-Id: I933ff5d912cbc7acce52155c605d9c19049c66aa
Reviewed-on: https://gerrit.libreoffice.org/63073Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

comphelper/source/misc/profilezone.cxx

@@ -7,6 +7,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+#include <sal/config.h>
+
+#include <atomic>
+
 #include <comphelper/sequence.hxx>
 #include <comphelper/profilezone.hxx>
 #include <osl/time.h>
@@ -15,7 +19,7 @@
 namespace comphelper
 {
 
-volatile bool ProfileZone::g_bRecording(false);
+std::atomic<bool> ProfileZone::g_bRecording(false);
 
 namespace ProfileRecording
 {

include/comphelper/profilezone.hxx

@@ -10,6 +10,10 @@
 #ifndef INCLUDED_COMPHELPER_PROFILEZONE_HXX
 #define INCLUDED_COMPHELPER_PROFILEZONE_HXX
 
+#include <sal/config.h>
+
+#include <atomic>
+
 #include <com/sun/star/uno/Sequence.h>
 #include <comphelper/comphelperdllapi.h>
 #include <rtl/ustring.hxx>
@@ -36,7 +40,7 @@ private:
     const char * m_sProfileId;
     long long const m_aCreateTime;
 public:
-    static volatile bool g_bRecording; // true during recording
+    static std::atomic<bool> g_bRecording; // true during recording
 
     // Note that the char pointer is stored as such in the ProfileZone object and used in the
     // destructor, so be sure to pass a pointer that stays valid for the duration of the object's