d8d914df68
* sysdeps/pthread/pthread.h: Add prototypes for pthread_spin_init, pthread_spin_destroy, pthread_spin_lock, pthread_spin_trylock, and pthread_spin_unlock. * sysdeps/pthread/bits/pthreadtypes.h: Change struct _pthread_fastlock into pthread_spinlock_t. Change all uses. * spinlock.c: Implement pthread_spin_lock. Rename __pthread_unlock to __pthread_spin_unlock and define weak alias for real name. Define pthread_spin_trylock, pthread_spin_init, and pthread_spin_destroy. Change all uses of _pthread_fastlock to pthread_spinlock_t. * spinlock.h: Rename __pthread_unlock to __pthread_spin_unlock. Change all uses of _pthread_fastlock to pthread_spinlock_t. * Versions [libpthread] (GLIBC_2.2): Add pthread_spin_init, pthread_spin_destroy, pthread_spin_lock, pthread_spin_trylock, and pthread_spin_unlock. * cancel.c: Use __pthread_spin_unlock instead of __pthread_unlock. Change all uses of _pthread_fastlock to pthread_spinlock_t. * condvar.c: Likewise. * internals.h: Likewise. * join.c: Likewise. * manager.c: Likewise. * mutex.c: Likewise. * pthread.c: Likewise. * rwlock.c: Likewise. * semaphore.c: Likewise. * signals.c: Likewise.
102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
/* Linuxthreads - a simple clone()-based implementation of Posix */
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/* threads for Linux. */
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/* Copyright (C) 1998 Xavier Leroy (Xavier.Leroy@inria.fr) */
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/* */
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/* This program is free software; you can redistribute it and/or */
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/* modify it under the terms of the GNU Library General Public License */
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/* as published by the Free Software Foundation; either version 2 */
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/* of the License, or (at your option) any later version. */
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/* */
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/* This program is distributed in the hope that it will be useful, */
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/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
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/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
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/* GNU Library General Public License for more details. */
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#if defined(TEST_FOR_COMPARE_AND_SWAP)
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extern int __pthread_has_cas;
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extern int __pthread_compare_and_swap(long * ptr, long oldval, long newval,
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int * spinlock);
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static inline int compare_and_swap(long * ptr, long oldval, long newval,
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int * spinlock)
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{
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if (__builtin_expect (__pthread_has_cas, 1))
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return __compare_and_swap(ptr, oldval, newval);
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else
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return __pthread_compare_and_swap(ptr, oldval, newval, spinlock);
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}
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#elif defined(HAS_COMPARE_AND_SWAP)
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static inline int compare_and_swap(long * ptr, long oldval, long newval,
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int * spinlock)
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{
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return __compare_and_swap(ptr, oldval, newval);
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}
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#else
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extern int __pthread_compare_and_swap(long * ptr, long oldval, long newval,
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int * spinlock);
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static inline int compare_and_swap(long * ptr, long oldval, long newval,
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int * spinlock)
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{
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return __pthread_compare_and_swap(ptr, oldval, newval, spinlock);
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}
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#endif
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/* Internal locks */
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extern void internal_function __pthread_lock(pthread_spinlock_t * lock,
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pthread_descr self);
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extern int __pthread_spin_unlock(pthread_spinlock_t *lock);
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static inline void __pthread_init_lock(pthread_spinlock_t * lock)
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{
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lock->__status = 0;
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lock->__spinlock = 0;
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}
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static inline int __pthread_trylock (pthread_spinlock_t * lock)
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{
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long oldstatus;
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do {
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oldstatus = lock->__status;
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if (oldstatus != 0) return EBUSY;
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} while(! compare_and_swap(&lock->__status, 0, 1, &lock->__spinlock));
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return 0;
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}
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#define LOCK_INITIALIZER {0, 0}
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/* Operations on pthread_atomic, which is defined in internals.h */
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static inline long atomic_increment(struct pthread_atomic *pa)
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{
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long oldval;
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do {
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oldval = pa->p_count;
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} while (!compare_and_swap(&pa->p_count, oldval, oldval + 1, &pa->p_spinlock));
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return oldval;
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}
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static inline long atomic_decrement(struct pthread_atomic *pa)
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{
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long oldval;
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do {
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oldval = pa->p_count;
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} while (!compare_and_swap(&pa->p_count, oldval, oldval - 1, &pa->p_spinlock));
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return oldval;
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}
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#define ATOMIC_INITIALIZER { 0, 0 }
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