[2/4] Replace __libc_multiple_threads with __libc_single_threaded

Message ID 20220608164941.3325089-3-adhemerval.zanella@linaro.org
State Superseded
Headers
Series Simplify internal single-threaded usage |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Adhemerval Zanella Netto June 8, 2022, 4:49 p.m. UTC
  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.
---
 nptl/Makefile                                 |  1 -
 nptl/allocatestack.c                          |  6 ----
 nptl/libc_multiple_threads.c                  | 28 -------------------
 nptl/pthread_cancel.c                         |  2 +-
 .../unix/sysv/linux/aarch64/single-thread.h   |  2 ++
 sysdeps/unix/sysv/linux/aarch64/sysdep.h      |  2 --
 sysdeps/unix/sysv/linux/alpha/sysdep.h        |  2 --
 sysdeps/unix/sysv/linux/arc/single-thread.h   |  2 ++
 sysdeps/unix/sysv/linux/arc/sysdep.h          |  2 --
 sysdeps/unix/sysv/linux/arm/single-thread.h   |  2 ++
 sysdeps/unix/sysv/linux/arm/sysdep.h          |  2 --
 sysdeps/unix/sysv/linux/hppa/single-thread.h  |  2 ++
 sysdeps/unix/sysv/linux/hppa/sysdep.h         |  2 --
 .../sysv/linux/microblaze/single-thread.h     |  2 ++
 sysdeps/unix/sysv/linux/microblaze/sysdep.h   |  2 --
 sysdeps/unix/sysv/linux/s390/single-thread.h  |  2 ++
 sysdeps/unix/sysv/linux/s390/sysdep.h         |  3 --
 sysdeps/unix/sysv/linux/single-thread.h       | 11 ++++----
 .../unix/sysv/linux/x86_64/single-thread.h    |  2 ++
 sysdeps/unix/sysv/linux/x86_64/sysdep.h       |  2 --
 20 files changed, 20 insertions(+), 59 deletions(-)
 delete mode 100644 nptl/libc_multiple_threads.c
 create mode 100644 sysdeps/unix/sysv/linux/aarch64/single-thread.h
 create mode 100644 sysdeps/unix/sysv/linux/arc/single-thread.h
 create mode 100644 sysdeps/unix/sysv/linux/arm/single-thread.h
 create mode 100644 sysdeps/unix/sysv/linux/hppa/single-thread.h
 create mode 100644 sysdeps/unix/sysv/linux/microblaze/single-thread.h
 create mode 100644 sysdeps/unix/sysv/linux/s390/single-thread.h
 create mode 100644 sysdeps/unix/sysv/linux/x86_64/single-thread.h
  

Patch

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..e1735279f2 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 = 0;
 #endif
     }
   while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,
diff --git a/sysdeps/unix/sysv/linux/aarch64/single-thread.h b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
@@ -0,0 +1,2 @@ 
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
index 3b230dccf1..f1853e012f 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
@@ -164,8 +164,6 @@ 
 # define HAVE_CLOCK_GETTIME64_VSYSCALL	"__kernel_clock_gettime"
 # define HAVE_GETTIMEOFDAY_VSYSCALL	"__kernel_gettimeofday"
 
-# define SINGLE_THREAD_BY_GLOBAL		1
-
 # undef INTERNAL_SYSCALL_RAW
 # define INTERNAL_SYSCALL_RAW(name, nr, args...)		\
   ({ long _sys_result;						\
diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
index 3051a744b4..77ec2b5400 100644
--- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
+++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
@@ -32,8 +32,6 @@ 
 #undef SYS_ify
 #define SYS_ify(syscall_name)	__NR_##syscall_name
 
-#define SINGLE_THREAD_BY_GLOBAL 1
-
 #ifdef __ASSEMBLER__
 #include <asm/pal.h>
 #include <alpha/regdef.h>
diff --git a/sysdeps/unix/sysv/linux/arc/single-thread.h b/sysdeps/unix/sysv/linux/arc/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arc/single-thread.h
@@ -0,0 +1,2 @@ 
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arc/sysdep.h b/sysdeps/unix/sysv/linux/arc/sysdep.h
index 29b0e0161c..d0c1a78381 100644
--- a/sysdeps/unix/sysv/linux/arc/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arc/sysdep.h
@@ -132,8 +132,6 @@  L (call_syscall_err):			ASM_LINE_SEP	\
 
 #else  /* !__ASSEMBLER__ */
 
-# define SINGLE_THREAD_BY_GLOBAL		1
-
 # if IS_IN (libc)
 extern long int __syscall_error (long int);
 hidden_proto (__syscall_error)
diff --git a/sysdeps/unix/sysv/linux/arm/single-thread.h b/sysdeps/unix/sysv/linux/arm/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/single-thread.h
@@ -0,0 +1,2 @@ 
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
index 7bdd218063..1f270b961e 100644
--- a/sysdeps/unix/sysv/linux/arm/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
@@ -408,8 +408,6 @@  __local_syscall_error:						\
 #define INTERNAL_SYSCALL_NCS(number, nr, args...)              \
   INTERNAL_SYSCALL_RAW (number, nr, args)
 
-#define SINGLE_THREAD_BY_GLOBAL	1
-
 #endif	/* __ASSEMBLER__ */
 
 #endif /* linux/arm/sysdep.h */
diff --git a/sysdeps/unix/sysv/linux/hppa/single-thread.h b/sysdeps/unix/sysv/linux/hppa/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/single-thread.h
@@ -0,0 +1,2 @@ 
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/hppa/sysdep.h b/sysdeps/unix/sysv/linux/hppa/sysdep.h
index 42f7705852..2f339a4bd6 100644
--- a/sysdeps/unix/sysv/linux/hppa/sysdep.h
+++ b/sysdeps/unix/sysv/linux/hppa/sysdep.h
@@ -474,6 +474,4 @@  L(pre_end):					ASM_LINE_SEP	\
 #define PTR_MANGLE(var) (void) (var)
 #define PTR_DEMANGLE(var) (void) (var)
 
-#define SINGLE_THREAD_BY_GLOBAL	1
-
 #endif /* _LINUX_HPPA_SYSDEP_H */
diff --git a/sysdeps/unix/sysv/linux/microblaze/single-thread.h b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
@@ -0,0 +1,2 @@ 
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/microblaze/sysdep.h b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
index dfd6312506..fda78f6467 100644
--- a/sysdeps/unix/sysv/linux/microblaze/sysdep.h
+++ b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
@@ -308,8 +308,6 @@  SYSCALL_ERROR_LABEL_DCL:                            \
 # define PTR_MANGLE(var) (void) (var)
 # define PTR_DEMANGLE(var) (void) (var)
 
-# define SINGLE_THREAD_BY_GLOBAL	1
-
 #undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
 #define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
 
diff --git a/sysdeps/unix/sysv/linux/s390/single-thread.h b/sysdeps/unix/sysv/linux/s390/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/single-thread.h
@@ -0,0 +1,2 @@ 
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
index 78c7e8c7e2..2d0a26779c 100644
--- a/sysdeps/unix/sysv/linux/s390/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
@@ -93,9 +93,6 @@ 
 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
 
-#define SINGLE_THREAD_BY_GLOBAL		1
-
-
 #define VDSO_NAME  "LINUX_2.6.29"
 #define VDSO_HASH  123718585
 
diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
index 4529a906d2..208edccce6 100644
--- a/sysdeps/unix/sysv/linux/single-thread.h
+++ b/sysdeps/unix/sysv/linux/single-thread.h
@@ -19,6 +19,10 @@ 
 #ifndef _SINGLE_THREAD_H
 #define _SINGLE_THREAD_H
 
+#ifndef __ASSEMBLER__
+# include <sys/single_threaded.h>
+#endif
+
 /* The default way to check if the process is single thread is by using the
    pthread_t 'multiple_threads' field.  However, for some architectures it is
    faster to either use an extra field on TCB or global variables (the TCB
@@ -27,16 +31,11 @@ 
    The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
    check to use global variables instead of the pthread_t field.  */
 
-#ifndef __ASSEMBLER__
-extern int __libc_multiple_threads;
-libc_hidden_proto (__libc_multiple_threads)
-#endif
-
 #if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
 # define SINGLE_THREAD_P \
   (THREAD_GETMEM (THREAD_SELF, header.multiple_threads) == 0)
 #else
-# define SINGLE_THREAD_P (__libc_multiple_threads == 0)
+# define SINGLE_THREAD_P (__libc_single_threaded != 0)
 #endif
 
 #define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
diff --git a/sysdeps/unix/sysv/linux/x86_64/single-thread.h b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
new file mode 100644
index 0000000000..a5d3a2aaf4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
@@ -0,0 +1,2 @@ 
+#define SINGLE_THREAD_BY_GLOBAL
+#include_next <single-thread.h>
diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
index e1ce3b62eb..740abefcfd 100644
--- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
@@ -379,8 +379,6 @@ 
 
 # define HAVE_CLONE3_WRAPPER			1
 
-# define SINGLE_THREAD_BY_GLOBAL		1
-
 #endif	/* __ASSEMBLER__ */