Update copyright dates with scripts/update-copyrights.

[thirdparty/glibc.git] / stdlib / cxa_atexit.c

diff --git a/stdlib/cxa_atexit.c b/stdlib/cxa_atexit.c
index 78acbbdb3d66f4989d672d01d0a673aea2d6e800..ce5d9f22b45f12b60b31f0b1c2ba4bce31e22e79 100644 (file)
--- a/stdlib/cxa_atexit.c
+++ b/stdlib/cxa_atexit.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999, 2001 Free Software Foundation, Inc.
+/* Copyright (C) 1999-2017 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -12,82 +12,122 @@
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
 
-#include <bits/libc-lock.h>
+#include <assert.h>
 #include <stdlib.h>
+#include <stdint.h>
+
+#include <libc-lock.h>
 #include "exit.h"
+#include <atomic.h>
+#include <sysdep.h>
+
+#undef __cxa_atexit
+
 
-/* Register a function to be called by exit or when a shared library
-   is unloaded.  This function is only called from code generated by
-   the C++ compiler.  */
 int
-__cxa_atexit (void (*func) (void *), void *arg, void *d)
+attribute_hidden
+__internal_atexit (void (*func) (void *), void *arg, void *d,
+                  struct exit_function_list **listp)
 {
-  struct exit_function *new = __new_exitfn ();
+  struct exit_function *new = __new_exitfn (listp);
 
   if (new == NULL)
     return -1;
 
-  new->flavor = ef_cxa;
+#ifdef PTR_MANGLE
+  PTR_MANGLE (func);
+#endif
   new->func.cxa.fn = (void (*) (void *, int)) func;
   new->func.cxa.arg = arg;
   new->func.cxa.dso_handle = d;
+  atomic_write_barrier ();
+  new->flavor = ef_cxa;
   return 0;
 }
 
 
+/* Register a function to be called by exit or when a shared library
+   is unloaded.  This function is only called from code generated by
+   the C++ compiler.  */
+int
+__cxa_atexit (void (*func) (void *), void *arg, void *d)
+{
+  return __internal_atexit (func, arg, d, &__exit_funcs);
+}
+libc_hidden_def (__cxa_atexit)
+
+
 /* We change global data, so we need locking.  */
 __libc_lock_define_initialized (static, lock)
 
 
 static struct exit_function_list initial;
 struct exit_function_list *__exit_funcs = &initial;
+uint64_t __new_exitfn_called;
 
 struct exit_function *
-__new_exitfn (void)
+__new_exitfn (struct exit_function_list **listp)
 {
+  struct exit_function_list *p = NULL;
   struct exit_function_list *l;
+  struct exit_function *r = NULL;
   size_t i = 0;
 
   __libc_lock_lock (lock);
 
-  for (l = __exit_funcs; l != NULL; l = l->next)
+  for (l = *listp; l != NULL; p = l, l = l->next)
     {
-      for (i = 0; i < l->idx; ++i)
-       if (l->fns[i].flavor == ef_free)
+      for (i = l->idx; i > 0; --i)
+       if (l->fns[i - 1].flavor != ef_free)
          break;
-      if (i < l->idx)
+
+      if (i > 0)
        break;
 
-      if (l->idx < sizeof (l->fns) / sizeof (l->fns[0]))
-       {
-         i = l->idx++;
-         break;
-       }
+      /* This block is completely unused.  */
+      l->idx = 0;
     }
 
-  if (l == NULL)
+  if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0]))
     {
-      l = (struct exit_function_list *)
-       malloc (sizeof (struct exit_function_list));
-      if (l != NULL)
+      /* The last entry in a block is used.  Use the first entry in
+        the previous block if it exists.  Otherwise create a new one.  */
+      if (p == NULL)
        {
-         l->next = __exit_funcs;
-         __exit_funcs = l;
+         assert (l != NULL);
+         p = (struct exit_function_list *)
+           calloc (1, sizeof (struct exit_function_list));
+         if (p != NULL)
+           {
+             p->next = *listp;
+             *listp = p;
+           }
+       }
 
-         l->idx = 1;
-         i = 0;
+      if (p != NULL)
+       {
+         r = &p->fns[0];
+         p->idx = 1;
        }
     }
+  else
+    {
+      /* There is more room in the block.  */
+      r = &l->fns[i];
+      l->idx = i + 1;
+    }
 
   /* Mark entry as used, but we don't know the flavor now.  */
-  if (l != NULL)
-    l->fns[i].flavor = ef_us;
+  if (r != NULL)
+    {
+      r->flavor = ef_us;
+      ++__new_exitfn_called;
+    }
 
   __libc_lock_unlock (lock);
 
-  return l == NULL ? NULL : &l->fns[i];
+  return r;
 }