[PATCH] Unify pthread_spin_[try]lock implementations.

[Maxim Kuvyrkov <maxim@codesourcery.com>]

On 29/06/2012, at 11:10 AM, Joseph S. Myers wrote:

>> diff --git a/sysdeps/mips/nptl/pthread_spin_trylock.c b/sysdeps/mips/nptl/pthread_spin_trylock.c
>> new file mode 100644
>> index 0000000..ed75813
>> --- /dev/null
>> +++ b/sysdeps/mips/nptl/pthread_spin_trylock.c
> 
> This file looks generic and essentially the same as the ARM and M68K 
> versions.  I think it would be better to put such a generic version in a 
> generic directory (maybe directly in nptl/), and remove the ARM and M68K 
> copies, rather than adding a third copy of the same generic 
> implementation.

Indeed.  The attached patches for glibc proper and ports unify pthread_spin_lock and pthread_spin_trylock for ARM, HPPA, M68K and MIPS.  I've tested these on MIPS, and the changes for other targets are only mechanical.

Any comments?

--
Maxim Kuvyrkov
CodeSourcery / Mentor Graphics

Add generic versions of pthread_spin_lock and pthread_spin_trylock.

	2012-07-09  Maxim Kuvyrkov  <maxim@codesourcery.com>

	* nptl/pthread_spin_lock.c: New file.
	* nptl/pthread_spin_trylock.c: New file.
---
 nptl/pthread_spin_lock.c    |   30 ++++++++++++++++++++++++++++++
 nptl/pthread_spin_trylock.c |   27 +++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 0 deletions(-)
 create mode 100644 nptl/pthread_spin_lock.c
 create mode 100644 nptl/pthread_spin_trylock.c

diff --git a/nptl/pthread_spin_lock.c b/nptl/pthread_spin_lock.c
new file mode 100644
index 0000000..1daa43d
--- /dev/null
+++ b/nptl/pthread_spin_lock.c
@@ -0,0 +1,30 @@
+/* pthread_spin_lock -- lock a spin lock.  Generic version.
+   Copyright (C) 2012 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <atomic.h>
+#include "pthreadP.h"
+
+int
+pthread_spin_lock (pthread_spinlock_t *lock)
+{
+  while (atomic_compare_and_exchange_val_acq (lock, 1, 0) != 0)
+    while (*lock != 0)
+      ;
+
+  return 0;
+}
diff --git a/nptl/pthread_spin_trylock.c b/nptl/pthread_spin_trylock.c
new file mode 100644
index 0000000..a097a86
--- /dev/null
+++ b/nptl/pthread_spin_trylock.c
@@ -0,0 +1,27 @@
+/* pthread_spin_trylock -- trylock a spin lock.  Generic version.
+   Copyright (C) 2012 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <atomic.h>
+#include "pthreadP.h"
+
+int
+pthread_spin_trylock (pthread_spinlock_t *lock)
+{
+  return atomic_compare_and_exchange_val_acq (lock, 1, 0) ? EBUSY : 0;
+}
-- 
1.7.4.1

Unify ARM, HPPA, M68K and MIPS pthread_spin_lock and pthread_spin_trylock.

2012-06-13  Maxim Kuvyrkov  <maxim@codesourcery.com>

	* sysdeps/arm/nptl/pthread_spin_lock.c: Remove, use generic version.
	* sysdeps/arm/nptl/pthread_spin_trylock.c: Same.
	* sysdeps/hppa/nptl/pthread_spin_lock.c: Same.
	* sysdeps/hppa/nptl/pthread_spin_trylock.c: Same.
	* sysdeps/m68k/nptl/pthread_spin_lock.c: Same.
	* sysdeps/m68k/nptl/pthread_spin_trylock.c: Same.
	* sysdeps/mips/nptl/pthread_spin_lock.S: Same.
	* sysdeps/mips/nptl/pthread_spin_trylock.S: Same.
---
 sysdeps/arm/nptl/pthread_spin_lock.c     |   29 ---------------------
 sysdeps/arm/nptl/pthread_spin_trylock.c  |   26 -------------------
 sysdeps/hppa/nptl/pthread_spin_lock.c    |   37 ---------------------------
 sysdeps/hppa/nptl/pthread_spin_trylock.c |   33 ------------------------
 sysdeps/m68k/nptl/pthread_spin_lock.c    |   30 ----------------------
 sysdeps/m68k/nptl/pthread_spin_trylock.c |   27 --------------------
 sysdeps/mips/nptl/pthread_spin_lock.S    |   36 ---------------------------
 sysdeps/mips/nptl/pthread_spin_trylock.S |   40 ------------------------------
 8 files changed, 0 insertions(+), 258 deletions(-)
 delete mode 100644 sysdeps/arm/nptl/pthread_spin_lock.c
 delete mode 100644 sysdeps/arm/nptl/pthread_spin_trylock.c
 delete mode 100644 sysdeps/hppa/nptl/pthread_spin_lock.c
 delete mode 100644 sysdeps/hppa/nptl/pthread_spin_trylock.c
 delete mode 100644 sysdeps/m68k/nptl/pthread_spin_lock.c
 delete mode 100644 sysdeps/m68k/nptl/pthread_spin_trylock.c
 delete mode 100644 sysdeps/mips/nptl/pthread_spin_lock.S
 delete mode 100644 sysdeps/mips/nptl/pthread_spin_trylock.S

diff --git a/sysdeps/arm/nptl/pthread_spin_lock.c b/sysdeps/arm/nptl/pthread_spin_lock.c
deleted file mode 100644
index 3a23bd3..0000000
--- a/sysdeps/arm/nptl/pthread_spin_lock.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/* Copyright (C) 2008 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <atomic.h>
-#include "pthreadP.h"
-
-int
-pthread_spin_lock (pthread_spinlock_t *lock)
-{
-  while (atomic_compare_and_exchange_val_acq (lock, 1, 0) != 0)
-   while (*lock != 0)
-    ;
-
-  return 0;
-}
diff --git a/sysdeps/arm/nptl/pthread_spin_trylock.c b/sysdeps/arm/nptl/pthread_spin_trylock.c
deleted file mode 100644
index 7d31180..0000000
--- a/sysdeps/arm/nptl/pthread_spin_trylock.c
+++ /dev/null
@@ -1,26 +0,0 @@
-/* Copyright (C) 2008 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <atomic.h>
-#include "pthreadP.h"
-
-int
-pthread_spin_trylock (pthread_spinlock_t *lock)
-{
-  return atomic_compare_and_exchange_val_acq (lock, 1, 0) ? EBUSY : 0;
-}
diff --git a/sysdeps/hppa/nptl/pthread_spin_lock.c b/sysdeps/hppa/nptl/pthread_spin_lock.c
deleted file mode 100644
index bcf2240..0000000
--- a/sysdeps/hppa/nptl/pthread_spin_lock.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Copyright (C) 2005 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <atomic.h>
-#include "pthreadP.h"
-
-int
-pthread_spin_lock (pthread_spinlock_t *lock)
-{
-#if 0
-  volatile unsigned int *addr = __ldcw_align (lock);
-
-  while (__ldcw (addr) == 0)
-    while (*addr == 0) ;
-
-  return 0;
-#endif
-
-  while (atomic_compare_and_exchange_val_acq(lock, 1, 0) == 1)
-    while (*lock == 1);
-  
-  return 0;
-}
diff --git a/sysdeps/hppa/nptl/pthread_spin_trylock.c b/sysdeps/hppa/nptl/pthread_spin_trylock.c
deleted file mode 100644
index a8028610..0000000
--- a/sysdeps/hppa/nptl/pthread_spin_trylock.c
+++ /dev/null
@@ -1,33 +0,0 @@
-/* Copyright (C) 2005 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <atomic.h>
-#include "pthreadP.h"
-
-int
-pthread_spin_trylock (pthread_spinlock_t *lock)
-{
-#if 0
-  volatile unsigned int *a = __ldcw_align (lock);
-
-  return __ldcw (a) ? 0 : EBUSY;
-#endif
-
-  return atomic_compare_and_exchange_val_acq(lock, 1, 0) ? EBUSY : 0;
-
-}
diff --git a/sysdeps/m68k/nptl/pthread_spin_lock.c b/sysdeps/m68k/nptl/pthread_spin_lock.c
deleted file mode 100644
index 90a8262..0000000
--- a/sysdeps/m68k/nptl/pthread_spin_lock.c
+++ /dev/null
@@ -1,30 +0,0 @@
-/* Copyright (C) 2010 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
-
-   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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <atomic.h>
-#include "pthreadP.h"
-
-int
-pthread_spin_lock (pthread_spinlock_t *lock)
-{
-  while (atomic_compare_and_exchange_val_acq(lock, 1, 0) != 0)
-   while (*lock != 0)
-    ;
-
-  return 0;
-}
diff --git a/sysdeps/m68k/nptl/pthread_spin_trylock.c b/sysdeps/m68k/nptl/pthread_spin_trylock.c
deleted file mode 100644
index f4b0c0d..0000000
--- a/sysdeps/m68k/nptl/pthread_spin_trylock.c
+++ /dev/null
@@ -1,27 +0,0 @@
-/* Copyright (C) 2010 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
-
-   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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <atomic.h>
-#include "pthreadP.h"
-
-int
-pthread_spin_trylock (pthread_spinlock_t *lock)
-{
-  return atomic_compare_and_exchange_val_acq(lock, 1, 0) ? EBUSY : 0;
-}
diff --git a/sysdeps/mips/nptl/pthread_spin_lock.S b/sysdeps/mips/nptl/pthread_spin_lock.S
deleted file mode 100644
index a8504f1..0000000
--- a/sysdeps/mips/nptl/pthread_spin_lock.S
+++ /dev/null
@@ -1,36 +0,0 @@
-/* Copyright (C) 2005 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <sys/asm.h>
-#include <sysdep.h>
-#include <sgidefs.h>
-
-ENTRY (pthread_spin_lock)
-	.set	push
-#if _MIPS_SIM == _ABIO32
-	.set	mips2
-#endif
-1:	ll	a2, 0(a0)
-	li	a1, 1
-	bnez	a2, 1b
-	sc	a1, 0(a0)
-	beqz	a1, 1b
-	MIPS_SYNC
-	.set	pop
-	li	v0, 0
-	ret
-PSEUDO_END (pthread_spin_lock)
diff --git a/sysdeps/mips/nptl/pthread_spin_trylock.S b/sysdeps/mips/nptl/pthread_spin_trylock.S
deleted file mode 100644
index 95b55c3..0000000
--- a/sysdeps/mips/nptl/pthread_spin_trylock.S
+++ /dev/null
@@ -1,40 +0,0 @@
-/* Copyright (C) 2005 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <sys/asm.h>
-#include <sysdep.h>
-#define _ERRNO_H 1
-#include <bits/errno.h>
-#include <sgidefs.h>
-
-ENTRY (pthread_spin_trylock)
-	.set	push
-#if _MIPS_SIM == _ABIO32
-	.set	mips2
-#endif
-	ll	a2, 0(a0)
-	li	a1, 1
-	bnez	a2, 1f
-	sc	a1, 0(a0)
-	beqz	a1, 1f
-	MIPS_SYNC
-	.set	pop
-	li	v0, 0
-	ret
-1:	li	v0, EBUSY
-	ret
-PSEUDO_END (pthread_spin_trylock)
-- 
1.7.4.1