From ef4009734b84903615be28b38638c166e5455692 Mon Sep 17 00:00:00 2001 From: Maxim Kuvyrkov Date: Wed, 15 Aug 2012 16:29:06 -0700 Subject: [PATCH] Add generic versions of pthread_spin_lock and pthread_spin_trylock. --- nptl/ChangeLog | 5 ++ nptl/pthread_spin_lock.c | 69 ++++++++++++++++++++++ .../arm/nptl => nptl}/pthread_spin_trylock.c | 7 ++- ports/ChangeLog.arm | 5 ++ ports/ChangeLog.hppa | 5 ++ ports/ChangeLog.m68k | 5 ++ ports/ChangeLog.mips | 6 ++ ports/sysdeps/arm/nptl/pthread_spin_lock.c | 18 ++---- ports/sysdeps/hppa/nptl/pthread_spin_lock.c | 26 ++------ ports/sysdeps/hppa/nptl/pthread_spin_trylock.c | 33 ----------- ports/sysdeps/m68k/nptl/pthread_spin_lock.c | 18 ++---- ports/sysdeps/mips/nptl/pthread_spin_lock.S | 36 ----------- .../nptl/pthread_spin_lock.c} | 16 ++--- ports/sysdeps/mips/nptl/pthread_spin_trylock.S | 40 ------------- 14 files changed, 123 insertions(+), 166 deletions(-) create mode 100644 nptl/pthread_spin_lock.c rename {ports/sysdeps/arm/nptl => nptl}/pthread_spin_trylock.c (78%) delete mode 100644 ports/sysdeps/hppa/nptl/pthread_spin_trylock.c delete mode 100644 ports/sysdeps/mips/nptl/pthread_spin_lock.S rename ports/sysdeps/{m68k/nptl/pthread_spin_trylock.c => mips/nptl/pthread_spin_lock.c} (68%) delete mode 100644 ports/sysdeps/mips/nptl/pthread_spin_trylock.S diff --git a/nptl/ChangeLog b/nptl/ChangeLog index 1deaa6a..0f31b4d 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -1,3 +1,8 @@ +2012-08-15 Maxim Kuvyrkov + + * pthread_spin_lock.c: New file. + * pthread_spin_trylock.c: New file. + 2012-08-08 Joseph Myers * allocatestack.c (setxid_signal_thread) [__ASSUME_TGKILL]: Make diff --git a/nptl/pthread_spin_lock.c b/nptl/pthread_spin_lock.c new file mode 100644 index 0000000..91733fb --- /dev/null +++ b/nptl/pthread_spin_lock.c @@ -0,0 +1,69 @@ +/* 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 + . */ + +#include +#include "pthreadP.h" + +/* A machine-specific version can define SPIN_LOCK_READS_BETWEEN_CMPXCHG + to the number of plain reads that it's optimal to spin on between uses + of atomic_compare_and_exchange_val_acq. If spinning forever is optimal + then use -1. If no plain reads here would ever be optimal, use 0. */ +#ifndef SPIN_LOCK_READS_BETWEEN_CMPXCHG +# warning machine-dependent file should define SPIN_LOCK_READS_BETWEEN_CMPXCHG +# define SPIN_LOCK_READS_BETWEEN_CMPXCHG 1000 +#endif + +int +pthread_spin_lock (pthread_spinlock_t *lock) +{ + /* atomic_exchange usually takes less instructions than + atomic_compare_and_exchange. On the other hand, + atomic_compare_and_exchange potentially generates less bus traffic + when the lock is locked. + We assume that the first try mostly will be successful, and we use + atomic_exchange. For the subsequent tries we use + atomic_compare_and_exchange. */ + if (atomic_exchange_acq (lock, 1) == 0) + return 0; + + do + { + /* The lock is contended and we need to wait. Going straight back + to cmpxchg is not a good idea on many targets as that will force + expensive memory synchronizations among processors and penalize other + running threads. + On the other hand, we do want to update memory state on the local core + once in a while to avoid spinning indefinitely until some event that + will happen to update local memory as a side-effect. */ + if (SPIN_LOCK_READS_BETWEEN_CMPXCHG >= 0) + { + int wait = SPIN_LOCK_READS_BETWEEN_CMPXCHG; + + while (*lock != 0 && wait > 0) + --wait; + } + else + { + while (*lock != 0) + ; + } + } + while (atomic_compare_and_exchange_val_acq (lock, 1, 0) != 0); + + return 0; +} diff --git a/ports/sysdeps/arm/nptl/pthread_spin_trylock.c b/nptl/pthread_spin_trylock.c similarity index 78% rename from ports/sysdeps/arm/nptl/pthread_spin_trylock.c rename to nptl/pthread_spin_trylock.c index 7d31180..db9372c 100644 --- a/ports/sysdeps/arm/nptl/pthread_spin_trylock.c +++ b/nptl/pthread_spin_trylock.c @@ -1,4 +1,5 @@ -/* Copyright (C) 2008 Free Software Foundation, Inc. +/* 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 @@ -12,7 +13,7 @@ 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 + License along with the GNU C Library; if not, see . */ #include @@ -22,5 +23,5 @@ int pthread_spin_trylock (pthread_spinlock_t *lock) { - return atomic_compare_and_exchange_val_acq (lock, 1, 0) ? EBUSY : 0; + return atomic_exchange_acq (lock, 1) ? EBUSY : 0; } diff --git a/ports/ChangeLog.arm b/ports/ChangeLog.arm index bb38c15..359bd0d 100644 --- a/ports/ChangeLog.arm +++ b/ports/ChangeLog.arm @@ -1,3 +1,8 @@ +2012-08-15 Maxim Kuvyrkov + + * sysdeps/arm/nptl/pthread_spin_lock.c: Use generic code. + * sysdeps/arm/nptl/pthread_spin_trylock.c: Remove, use generic version. + 2012-08-14 Roland McGrath * sysdeps/unix/sysv/linux/arm/nptl/bits/atomic.h: Renamed to ... diff --git a/ports/ChangeLog.hppa b/ports/ChangeLog.hppa index 0501211..a28fbce 100644 --- a/ports/ChangeLog.hppa +++ b/ports/ChangeLog.hppa @@ -1,3 +1,8 @@ +2012-08-15 Maxim Kuvyrkov + + * sysdeps/hppa/nptl/pthread_spin_lock.c: Use generic code. + * sysdeps/hppa/nptl/pthread_spin_trylock.c: Remove, use generic version. + 2012-08-12 Mike Frysinger * sysdeps/unix/sysv/linux/hppa/syscalls.list: Add prlimit64. diff --git a/ports/ChangeLog.m68k b/ports/ChangeLog.m68k index 9fc9d38..62a8eb3 100644 --- a/ports/ChangeLog.m68k +++ b/ports/ChangeLog.m68k @@ -1,3 +1,8 @@ +2012-08-15 Maxim Kuvyrkov + + * sysdeps/m68k/nptl/pthread_spin_lock.c: Use generic code. + * sysdeps/m68k/nptl/pthread_spin_trylock.c: Remove, use generic version. + 2012-08-10 Andreas Schwab * sysdeps/m68k/ldsodefs.h (m68k_gnu_pltenter): Remove const on diff --git a/ports/ChangeLog.mips b/ports/ChangeLog.mips index b69846f..5187772 100644 --- a/ports/ChangeLog.mips +++ b/ports/ChangeLog.mips @@ -1,3 +1,9 @@ +2012-08-15 Maxim Kuvyrkov + + * sysdeps/mips/nptl/pthread_spin_lock.S: Remove, use generic version. + * sysdeps/mips/nptl/pthread_spin_lock.c: New file. + * sysdeps/mips/nptl/pthread_spin_trylock.S: Remove, use generic version. + 2012-08-15 Joseph Myers * sysdeps/mips/dl-lookup.c: Update from generic version. diff --git a/ports/sysdeps/arm/nptl/pthread_spin_lock.c b/ports/sysdeps/arm/nptl/pthread_spin_lock.c index 3a23bd3..4f81571 100644 --- a/ports/sysdeps/arm/nptl/pthread_spin_lock.c +++ b/ports/sysdeps/arm/nptl/pthread_spin_lock.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2008 Free Software Foundation, Inc. +/* Copyright (C) 2008-2012 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 @@ -15,15 +15,9 @@ License along with the GNU C Library. If not, see . */ -#include -#include "pthreadP.h" +#define SPIN_LOCK_READS_BETWEEN_CMPXCHG 1000 -int -pthread_spin_lock (pthread_spinlock_t *lock) -{ - while (atomic_compare_and_exchange_val_acq (lock, 1, 0) != 0) - while (*lock != 0) - ; - - return 0; -} +/* We can't use the normal "#include " because + it will resolve to this very file. Using "sysdeps/.." as reference to the + top level directory does the job. */ +#include diff --git a/ports/sysdeps/hppa/nptl/pthread_spin_lock.c b/ports/sysdeps/hppa/nptl/pthread_spin_lock.c index bcf2240..e011853 100644 --- a/ports/sysdeps/hppa/nptl/pthread_spin_lock.c +++ b/ports/sysdeps/hppa/nptl/pthread_spin_lock.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2005 Free Software Foundation, Inc. +/* Copyright (C) 2005-2012 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 @@ -15,23 +15,9 @@ License along with the GNU C Library. If not, see . */ -#include -#include "pthreadP.h" +#define SPIN_LOCK_READS_BETWEEN_CMPXCHG 1000 -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; -} +/* We can't use the normal "#include " because + it will resolve to this very file. Using "sysdeps/.." as reference to the + top level directory does the job. */ +#include diff --git a/ports/sysdeps/hppa/nptl/pthread_spin_trylock.c b/ports/sysdeps/hppa/nptl/pthread_spin_trylock.c deleted file mode 100644 index a8028610..0000000 --- a/ports/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 - . */ - -#include -#include -#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/ports/sysdeps/m68k/nptl/pthread_spin_lock.c b/ports/sysdeps/m68k/nptl/pthread_spin_lock.c index 90a8262..2616a7f 100644 --- a/ports/sysdeps/m68k/nptl/pthread_spin_lock.c +++ b/ports/sysdeps/m68k/nptl/pthread_spin_lock.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2010 Free Software Foundation, Inc. +/* Copyright (C) 2010-2012 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Maxim Kuvyrkov , 2010. @@ -16,15 +16,9 @@ License along with the GNU C Library. If not, see . */ -#include -#include "pthreadP.h" +#define SPIN_LOCK_READS_BETWEEN_CMPXCHG 1000 -int -pthread_spin_lock (pthread_spinlock_t *lock) -{ - while (atomic_compare_and_exchange_val_acq(lock, 1, 0) != 0) - while (*lock != 0) - ; - - return 0; -} +/* We can't use the normal "#include " because + it will resolve to this very file. Using "sysdeps/.." as reference to the + top level directory does the job. */ +#include diff --git a/ports/sysdeps/mips/nptl/pthread_spin_lock.S b/ports/sysdeps/mips/nptl/pthread_spin_lock.S deleted file mode 100644 index a8504f1..0000000 --- a/ports/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 - . */ - -#include -#include -#include - -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/ports/sysdeps/m68k/nptl/pthread_spin_trylock.c b/ports/sysdeps/mips/nptl/pthread_spin_lock.c similarity index 68% rename from ports/sysdeps/m68k/nptl/pthread_spin_trylock.c rename to ports/sysdeps/mips/nptl/pthread_spin_lock.c index f4b0c0d..f39b018 100644 --- a/ports/sysdeps/m68k/nptl/pthread_spin_trylock.c +++ b/ports/sysdeps/mips/nptl/pthread_spin_lock.c @@ -1,6 +1,5 @@ -/* Copyright (C) 2010 Free Software Foundation, Inc. +/* Copyright (C) 2012 Free Software Foundation, Inc. This file is part of the GNU C Library. - Contributed by Maxim Kuvyrkov , 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 @@ -16,12 +15,9 @@ License along with the GNU C Library. If not, see . */ -#include -#include -#include "pthreadP.h" +#define SPIN_LOCK_READS_BETWEEN_CMPXCHG 1000 -int -pthread_spin_trylock (pthread_spinlock_t *lock) -{ - return atomic_compare_and_exchange_val_acq(lock, 1, 0) ? EBUSY : 0; -} +/* We can't use the normal "#include " because + it will resolve to this very file. Using "sysdeps/.." as reference to the + top level directory does the job. */ +#include diff --git a/ports/sysdeps/mips/nptl/pthread_spin_trylock.S b/ports/sysdeps/mips/nptl/pthread_spin_trylock.S deleted file mode 100644 index 95b55c3..0000000 --- a/ports/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 - . */ - -#include -#include -#define _ERRNO_H 1 -#include -#include - -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) -- 2.7.4