Replace __libc_multiple_threads with __libc_single_threaded

And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL,
since header inclusion single-thread.h is in the wrong order, the define
needs to come before including sysdeps/unix/sysdep.h.  The macro
is now moved to a per-arch single-threade.h header.

The SINGLE_THREAD_P is used on some more places.

Checked on aarch64-linux-gnu and x86_64-linux-gnu.

4 files changed, 1 insertions, 36 deletions

diff --git a/nptl/Makefile b/nptl/Makefile
index b585663974..3d2ce8af8a 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -50,7 +50,6 @@ routines = \
   events \
   futex-internal \
   libc-cleanup \
-  libc_multiple_threads \
   lowlevellock \
   nptl-stack \
   nptl_deallocate_tsd \
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index 01a282f3f6..98f5f6dd85 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -292,9 +292,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
 
       /* This is at least the second thread.  */
       pd->header.multiple_threads = 1;
-#ifndef TLS_MULTIPLE_THREADS_IN_TCB
-      __libc_multiple_threads = 1;
-#endif
 
 #ifdef NEED_DL_SYSINFO
       SETUP_THREAD_SYSINFO (pd);
@@ -413,9 +410,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
 
 	  /* This is at least the second thread.  */
 	  pd->header.multiple_threads = 1;
-#ifndef TLS_MULTIPLE_THREADS_IN_TCB
-	  __libc_multiple_threads = 1;
-#endif
 
 #ifdef NEED_DL_SYSINFO
 	  SETUP_THREAD_SYSINFO (pd);
diff --git a/nptl/libc_multiple_threads.c b/nptl/libc_multiple_threads.c
deleted file mode 100644
index 0c2dc33d0d..0000000000
--- a/nptl/libc_multiple_threads.c
+++ /dev/null
@@ -1,28 +0,0 @@
-/* Copyright (C) 2002-2022 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <pthreadP.h>
-
-#if IS_IN (libc)
-# ifndef TLS_MULTIPLE_THREADS_IN_TCB
-/* Variable set to a nonzero value either if more than one thread runs or ran,
-   or if a single-threaded process is trying to cancel itself.  See
-   nptl/descr.h for more context on the single-threaded process case.  */
-int __libc_multiple_threads;
-libc_hidden_data_def (__libc_multiple_threads)
-# endif
-#endif
diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
index e67b2df5cc..459317df49 100644
--- a/nptl/pthread_cancel.c
+++ b/nptl/pthread_cancel.c
@@ -161,7 +161,7 @@ __pthread_cancel (pthread_t th)
 	   points get executed.  */
 	THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
-      __libc_multiple_threads = 1;
+	__libc_single_threaded_internal = 0;
 #endif
     }
   while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,