Add SDT probes for interning rtl_uStrings.

This adds RTL_LOG_STRING_INTERN_NEW and RTL_LOG_STRING_INTERN_DELETE
which are connected to SDT probes if available. It introduces two new
SDT probes. new_string_intern_16 and delete_string_intern_16
(there is currently no interning for 8-bit rtl_Strings).
For consistency both have the same 4 arguments as new_string_(8|16)
and delete_string_(8|16). new_string_intern_16 has as 5th argument
the address of the original rtl_uString being interned (which may
or may not be the same as $arg1).

Change-Id: Ib117bba932c1908abc70a7fdd4140c0af76d54cb
Reviewed-on: https://gerrit.libreoffice.org/5308Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sal/rtl/strimp.hxx

@@ -56,15 +56,25 @@ sal_Bool rtl_ImplIsWhitespace( sal_Unicode c );
 #  define PROBE_NAME(n,b) PROBE_SNAME(n,b)
 #  define PROBE_NEW PROBE_NAME (new_string,RTL_LOG_STRING_BITS)
 #  define PROBE_DEL PROBE_NAME (delete_string,RTL_LOG_STRING_BITS)
+#  define PROBE_INTERN_NEW PROBE_NAME (new_string_intern,RTL_LOG_STRING_BITS)
+#  define PROBE_INTERN_DEL PROBE_NAME (delete_string_intern,RTL_LOG_STRING_BITS)
 #  define RTL_LOG_STRING_NEW(s) \
     DTRACE_PROBE4(libreoffice, PROBE_NEW, s, \
                   (s)->refCount, (s)->length, (s)->buffer)
 #  define RTL_LOG_STRING_DELETE(s) \
     DTRACE_PROBE4(libreoffice, PROBE_DEL, s, \
                   (s)->refCount, (s)->length, (s)->buffer)
+#  define RTL_LOG_STRING_INTERN_NEW(s,o) \
+    DTRACE_PROBE5(libreoffice, PROBE_INTERN_NEW, s, \
+                  (s)->refCount, (s)->length, (s)->buffer, o)
+#  define RTL_LOG_STRING_INTERN_DELETE(s) \
+    DTRACE_PROBE4(libreoffice, PROBE_INTERN_DEL, s, \
+                  (s)->refCount, (s)->length, (s)->buffer)
 #else
 #  define RTL_LOG_STRING_NEW(s)
 #  define RTL_LOG_STRING_DELETE(s)
+#  define RTL_LOG_STRING_INTERN_NEW(s,o)
+#  define RTL_LOG_STRING_INTERN_DELETE(s)
 #endif /* USE_SDT_PROBES */
 
 #endif /* INCLUDED_RTL_SOURCE_STRIMP_HXX */

sal/rtl/ustring.cxx

@@ -817,6 +817,8 @@ static void rtl_ustring_intern_internal( rtl_uString ** newStr,
 
     osl_releaseMutex( pPoolMutex );
 
+    RTL_LOG_STRING_INTERN_NEW(*newStr, str);
+
     if( can_return && *newStr != str )
     { /* we dupped, then found a match */
         rtl_freeMemory( str );
@@ -947,6 +949,7 @@ internRelease (rtl_uString *pThis)
     if ( SAL_STRING_REFCOUNT(
              osl_atomic_decrement( &(pThis->refCount) ) ) == 0)
     {
+        RTL_LOG_STRING_INTERN_DELETE(pThis);
         pPoolMutex = getInternMutex();
         osl_acquireMutex( pPoolMutex );