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, 4 insertions, 0 deletions

diff --git a/stdlib/Versions b/stdlib/Versions
index 250bd5fad7..f1777dfcf4 100644
--- a/stdlib/Versions
+++ b/stdlib/Versions
@@ -106,6 +106,9 @@ libc {
   GLIBC_2.17 {
     secure_getenv;
   }
+  GLIBC_2.18 {
+    __cxa_thread_atexit_impl;
+  }
   GLIBC_PRIVATE {
     # functions which have an additional interface since they are
     # are cancelable.
@@ -114,5 +117,6 @@ libc {
     __abort_msg;
     # Used from other libraries
     __libc_secure_getenv;
+    __call_tls_dtors;
   }
 }