C++11 thread_local destructors support

This feature is specifically for the C++ compiler to offload calling
thread_local object destructors on thread program exit, to glibc.
This is to overcome the possible complication of destructors of
thread_local objects getting called after the DSO in which they're
defined is unloaded by the dynamic linker.  The DSO is marked as
'unloadable' if it has a constructed thread_local object and marked as
'unloadable' again when all the constructed thread_local objects
defined in it are destroyed.

1 files changed, 3 insertions, 0 deletions

diff --git a/include/link.h b/include/link.h
index 230e95d6c8..7dc3cd1e32 100644
--- a/include/link.h
+++ b/include/link.h
@@ -302,6 +302,9 @@ struct link_map
     /* Index of the module in the dtv array.  */
     size_t l_tls_modid;
 
+    /* Number of thread_local objects constructed by this DSO.  */
+    size_t l_tls_dtor_count;
+
     /* Information used to change permission after the relocations are
        done.  */
     ElfW(Addr) l_relro_addr;