From c68d0fa2d88fc2134a38d99e7e944828384a7671 Mon Sep 17 00:00:00 2001 From: Austin Foxley Date: Sat, 17 Oct 2009 12:26:24 -0700 Subject: libpthread/nptl: core of the "Native Posix Threading Library" for uClibc targetting arm,sh,i386,mips,sparc for now Signed-off-by: Austin Foxley --- .../sysdeps/unix/sysv/linux/arm/lowlevellock.h | 340 +++++++++++++++++++++ 1 file changed, 340 insertions(+) create mode 100644 libpthread/nptl/sysdeps/unix/sysv/linux/arm/lowlevellock.h (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux/arm/lowlevellock.h') diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/arm/lowlevellock.h b/libpthread/nptl/sysdeps/unix/sysv/linux/arm/lowlevellock.h new file mode 100644 index 000000000..df5833c46 --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/arm/lowlevellock.h @@ -0,0 +1,340 @@ +/* Copyright (C) 2005, 2006 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 Libr \ary; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _LOWLEVELLOCK_H +#define _LOWLEVELLOCK_H 1 + +#include +#include +#include +#include +#include + +#define FUTEX_WAIT 0 +#define FUTEX_WAKE 1 +#define FUTEX_REQUEUE 3 +#define FUTEX_CMP_REQUEUE 4 +#define FUTEX_WAKE_OP 5 +#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) + +/* Initializer for compatibility lock. */ +#define LLL_MUTEX_LOCK_INITIALIZER (0) + +#define lll_futex_wait(futexp, val) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 4, \ + (futexp), FUTEX_WAIT, (val), 0); \ + __ret; \ + }) + +#define lll_futex_timed_wait(futexp, val, timespec) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 4, \ + (futexp), FUTEX_WAIT, (val), (timespec)); \ + __ret; \ + }) + +#define lll_futex_wake(futexp, nr) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 4, \ + (futexp), FUTEX_WAKE, (nr), 0); \ + __ret; \ + }) + +#define lll_robust_mutex_dead(futexv) \ + do \ + { \ + int *__futexp = &(futexv); \ + atomic_or (__futexp, FUTEX_OWNER_DIED); \ + lll_futex_wake (__futexp, 1); \ + } \ + while (0) + +/* Returns non-zero if error happened, zero if success. */ +#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 6, \ + (futexp), FUTEX_CMP_REQUEUE, (nr_wake), \ + (nr_move), (mutex), (val)); \ + __ret; \ + }) + + +/* Returns non-zero if error happened, zero if success. */ +#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2) \ + ({ \ + INTERNAL_SYSCALL_DECL (__err); \ + long int __ret; \ + __ret = INTERNAL_SYSCALL (futex, __err, 6, \ + (futexp), FUTEX_WAKE_OP, (nr_wake), \ + (nr_wake2), (futexp2), \ + FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \ + __ret; \ + }) + + +static inline int __attribute__((always_inline)) +__lll_mutex_trylock (int *futex) +{ + int flag = 1, old; +#ifdef __thumb__ + old = atomic_exchange_acq (futex, flag); + if (old < 1) + flag = 0; + else if (old > 1) + flag = atomic_exchange_acq (futex, old); +#else + __asm__ __volatile__ ( + "\tswp %[old], %[flag], [%[futex]] @ try to take the lock\n" + "\tcmp %[old], #1 @ check old lock value\n" + "\tmovlo %[flag], #0 @ if we got it, return 0\n" + "\tswphi %[flag], %[old], [%[futex]] @ if it was contested,\n" + " @ restore the contested flag,\n" + " @ and check whether that won." + : [futex] "+&r" (futex), [flag] "+&r" (flag), [old] "=&r" (old) + : : "memory" ); +#endif + + return flag; +} +#define lll_mutex_trylock(lock) __lll_mutex_trylock (&(lock)) + + +static inline int __attribute__((always_inline)) +__lll_mutex_cond_trylock (int *futex) +{ + int flag = 2, old; +#ifdef __thumb__ + old = atomic_exchange_acq (futex, flag); + if (old < 1) + flag = 0; + else if (old > 1) + flag = atomic_exchange_acq (futex, old); +#else + __asm__ __volatile__ ( + "\tswp %[old], %[flag], [%[futex]] @ try to take the lock\n" + "\tcmp %[old], #1 @ check old lock value\n" + "\tmovlo %[flag], #0 @ if we got it, return 0\n" + "\tswphi %[flag], %[old], [%[futex]] @ if it was contested,\n" + " @ restore the contested flag,\n" + " @ and check whether that won." + : [futex] "+&r" (futex), [flag] "+&r" (flag), [old] "=&r" (old) + : : "memory" ); +#endif + + return flag; +} +#define lll_mutex_cond_trylock(lock) __lll_mutex_cond_trylock (&(lock)) + + +static inline int __attribute__((always_inline)) +__lll_robust_mutex_trylock(int *futex, int id) +{ + return atomic_compare_and_exchange_val_acq (futex, id, 0) != 0; +} +#define lll_robust_mutex_trylock(lock, id) \ + __lll_robust_mutex_trylock (&(lock), id) + +extern int __lll_robust_lock_wait (int *futex) attribute_hidden; + +static inline void __attribute__((always_inline)) +__lll_mutex_lock (int *futex) +{ + int val = atomic_exchange_acq (futex, 1); + + if (__builtin_expect (val != 0, 0)) + { + while (atomic_exchange_acq (futex, 2) != 0) + lll_futex_wait (futex, 2); + } +} +#define lll_mutex_lock(futex) __lll_mutex_lock (&(futex)) + + +static inline int __attribute__ ((always_inline)) +__lll_robust_mutex_lock (int *futex, int id) +{ + int result = 0; + if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0) + result = __lll_robust_lock_wait (futex); + return result; +} +#define lll_robust_mutex_lock(futex, id) \ + __lll_robust_mutex_lock (&(futex), id) + + +static inline void __attribute__ ((always_inline)) +__lll_mutex_cond_lock (int *futex) +{ + int val = atomic_exchange_acq (futex, 2); + + if (__builtin_expect (val != 0, 0)) + { + while (atomic_exchange_acq (futex, 2) != 0) + lll_futex_wait (futex, 2); + } +} +#define lll_mutex_cond_lock(futex) __lll_mutex_cond_lock (&(futex)) + + +#define lll_robust_mutex_cond_lock(futex, id) \ + __lll_robust_mutex_lock (&(futex), (id) | FUTEX_WAITERS) + + +extern int __lll_timedlock_wait (int *futex, const struct timespec *) + attribute_hidden; +extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *) + attribute_hidden; + +static inline int __attribute__ ((always_inline)) +__lll_mutex_timedlock (int *futex, const struct timespec *abstime) +{ + int result = 0; + int val = atomic_exchange_acq (futex, 1); + + if (__builtin_expect (val != 0, 0)) + result = __lll_timedlock_wait (futex, abstime); + return result; +} +#define lll_mutex_timedlock(futex, abstime) \ + __lll_mutex_timedlock (&(futex), abstime) + + +static inline int __attribute__ ((always_inline)) +__lll_robust_mutex_timedlock (int *futex, const struct timespec *abstime, + int id) +{ + int result = 0; + if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0) + result = __lll_robust_timedlock_wait (futex, abstime); + return result; +} +#define lll_robust_mutex_timedlock(futex, abstime, id) \ + __lll_robust_mutex_timedlock (&(futex), abstime, id) + + +static inline void __attribute__ ((always_inline)) +__lll_mutex_unlock (int *futex) +{ + int val = atomic_exchange_rel (futex, 0); + if (__builtin_expect (val > 1, 0)) + lll_futex_wake (futex, 1); +} +#define lll_mutex_unlock(futex) __lll_mutex_unlock(&(futex)) + + +static inline void __attribute__ ((always_inline)) +__lll_robust_mutex_unlock (int *futex, int mask) +{ + int val = atomic_exchange_rel (futex, 0); + if (__builtin_expect (val & mask, 0)) + lll_futex_wake (futex, 1); +} +#define lll_robust_mutex_unlock(futex) \ + __lll_robust_mutex_unlock(&(futex), FUTEX_WAITERS) + + +static inline void __attribute__ ((always_inline)) +__lll_mutex_unlock_force (int *futex) +{ + (void) atomic_exchange_rel (futex, 0); + lll_futex_wake (futex, 1); +} +#define lll_mutex_unlock_force(futex) __lll_mutex_unlock_force(&(futex)) + + +#define lll_mutex_islocked(futex) \ + (futex != 0) + + +/* Our internal lock implementation is identical to the binary-compatible + mutex implementation. */ + +/* Type for lock object. */ +typedef int lll_lock_t; + +/* Initializers for lock. */ +#define LLL_LOCK_INITIALIZER (0) +#define LLL_LOCK_INITIALIZER_LOCKED (1) + +extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; + +/* The states of a lock are: + 0 - untaken + 1 - taken by one user + >1 - taken by more users */ + +#define lll_trylock(lock) lll_mutex_trylock (lock) +#define lll_lock(lock) lll_mutex_lock (lock) +#define lll_unlock(lock) lll_mutex_unlock (lock) +#define lll_islocked(lock) lll_mutex_islocked (lock) + +/* The kernel notifies a process which uses CLONE_CLEARTID via futex + wakeup when the clone terminates. The memory location contains the + thread ID while the clone is running and is reset to zero + afterwards. */ +#define lll_wait_tid(tid) \ + do { \ + __typeof (tid) __tid; \ + while ((__tid = (tid)) != 0) \ + lll_futex_wait (&(tid), __tid); \ + } while (0) + +extern int __lll_timedwait_tid (int *, const struct timespec *) + attribute_hidden; + +#define lll_timedwait_tid(tid, abstime) \ + ({ \ + int __res = 0; \ + if ((tid) != 0) \ + __res = __lll_timedwait_tid (&(tid), (abstime)); \ + __res; \ + }) + + +/* Conditional variable handling. */ + +extern void __lll_cond_wait (pthread_cond_t *cond) + attribute_hidden; +extern int __lll_cond_timedwait (pthread_cond_t *cond, + const struct timespec *abstime) + attribute_hidden; +extern void __lll_cond_wake (pthread_cond_t *cond) + attribute_hidden; +extern void __lll_cond_broadcast (pthread_cond_t *cond) + attribute_hidden; + +#define lll_cond_wait(cond) \ + __lll_cond_wait (cond) +#define lll_cond_timedwait(cond, abstime) \ + __lll_cond_timedwait (cond, abstime) +#define lll_cond_wake(cond) \ + __lll_cond_wake (cond) +#define lll_cond_broadcast(cond) \ + __lll_cond_broadcast (cond) + +#endif /* lowlevellock.h */ + -- cgit v1.2.3