diff --git a/elf/dl-support.c b/elf/dl-support.c
index 0155718175..68abf606ca 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -195,7 +195,6 @@ int _dl_stack_cache_lock;
when it was not, we do it by calling this function.
It returns an errno code or zero on success. */
int (*_dl_make_stack_executable_hook) (void **) = _dl_make_stack_executable;
-int _dl_thread_gscope_count;
void (*_dl_init_static_tls) (struct link_map *) = &_dl_nothread_init_static_tls;
#endif
struct dl_scope_free_list *_dl_scope_free_list;
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 31c7d3945b..5a779ae1a3 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -487,8 +487,6 @@ struct rtld_global
/* Mutex protecting the stack lists. */
EXTERN int _dl_stack_cache_lock;
#else
- EXTERN int _dl_thread_gscope_count;
-
/* The total number of thread IDs currently in use, or on the list of
available thread IDs. */
EXTERN int _dl_pthread_num_threads;
@@ -1379,10 +1377,8 @@ __rtld_mutex_init (void)
}
#endif /* !PTHREAD_IN_LIBC */
-#if THREAD_GSCOPE_IN_TCB
void __thread_gscope_wait (void) attribute_hidden;
# define THREAD_GSCOPE_WAIT() __thread_gscope_wait ()
-#endif
__END_DECLS
diff --git a/sysdeps/htl/dl-thread_gscope_wait.c b/sysdeps/htl/dl-thread_gscope_wait.c
new file mode 100644
index 0000000000..b277217b8e
--- /dev/null
+++ b/sysdeps/htl/dl-thread_gscope_wait.c
@@ -0,0 +1,55 @@
+/* Out-of-line notification function for the GSCOPE locking mechanism.
+ Copyright (C) 2007-2021 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
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ 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, see
+ . */
+
+#include
+#include
+#include
+
+void
+__thread_gscope_wait (void)
+{
+ size_t i;
+ struct __pthread *t;
+ int *gscope_flagp;
+
+ lll_lock (GL (dl_pthread_threads_lock), LLL_PRIVATE);
+
+ /* Iterate over the list of threads. */
+ for (i = 0; i < GL (dl_pthread_num_threads); ++i)
+ {
+ t = GL (dl_pthread_threads[i]);
+ if (t == NULL || t->tcb->gscope_flag == THREAD_GSCOPE_FLAG_UNUSED)
+ continue;
+
+ gscope_flagp = &t->tcb->gscope_flag;
+
+ /* We have to wait until this thread is done with the global
+ scope. First tell the thread that we are waiting and
+ possibly have to be woken. */
+ if (atomic_compare_and_exchange_bool_acq (gscope_flagp,
+ THREAD_GSCOPE_FLAG_WAIT,
+ THREAD_GSCOPE_FLAG_USED))
+ continue;
+
+ do
+ lll_wait (gscope_flagp, THREAD_GSCOPE_FLAG_WAIT, LLL_PRIVATE);
+ while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT);
+ }
+
+ lll_unlock (GL (dl_pthread_threads_lock), LLL_PRIVATE);
+}
diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
index 057b2613f3..c70ea73a81 100644
--- a/sysdeps/mach/hurd/i386/tls.h
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -369,6 +369,25 @@ _hurd_tls_new (thread_t child, struct i386_thread_state *state, tcbhead_t *tcb)
return err;
}
+/* Global scope switch support. */
+# define THREAD_GSCOPE_FLAG_UNUSED 0
+# define THREAD_GSCOPE_FLAG_USED 1
+# define THREAD_GSCOPE_FLAG_WAIT 2
+
+# define THREAD_GSCOPE_SET_FLAG() \
+ THREAD_SETMEM (THREAD_SELF, gscope_flag, THREAD_GSCOPE_FLAG_USED)
+
+# define THREAD_GSCOPE_RESET_FLAG() \
+ ({ \
+ int __flag; \
+ asm volatile ("xchgl %0, %%gs:%P1" \
+ : "=r" (__flag) \
+ : "i" (offsetof (tcbhead_t, gscope_flag)), \
+ "0" (THREAD_GSCOPE_FLAG_UNUSED)); \
+ if (__flag == THREAD_GSCOPE_FLAG_WAIT) \
+ lll_wake (THREAD_SELF->gscope_flag, LLL_PRIVATE); \
+ })
+
#endif /* !__ASSEMBLER__ */
#endif /* i386/tls.h */
diff --git a/sysdeps/mach/hurd/tls.h b/sysdeps/mach/hurd/tls.h
index f83956d3d7..98dc319745 100644
--- a/sysdeps/mach/hurd/tls.h
+++ b/sysdeps/mach/hurd/tls.h
@@ -52,25 +52,7 @@
# define GET_DTV(descr) \
(((tcbhead_t *) (descr))->dtv)
-/* Global scope switch support. */
-#define THREAD_GSCOPE_IN_TCB 0
-#define THREAD_GSCOPE_GLOBAL
-#define THREAD_GSCOPE_SET_FLAG() \
- atomic_exchange_and_add_acq (&GL(dl_thread_gscope_count), 1)
-#define THREAD_GSCOPE_RESET_FLAG() \
- do \
- if (atomic_exchange_and_add_rel (&GL(dl_thread_gscope_count), -1) == 1) \
- lll_wake (GL(dl_thread_gscope_count), 0); \
- while (0)
-#define THREAD_GSCOPE_WAIT() \
- do \
- { \
- int count; \
- atomic_write_barrier (); \
- while ((count = GL(dl_thread_gscope_count))) \
- lll_wait (GL(dl_thread_gscope_count), count, 0); \
- } \
- while (0)
+# define THREAD_GSCOPE_IN_TCB 0
#endif /* !ASSEMBLER */