diff options
author | Eric Andersen <andersen@codepoet.org> | 2002-02-20 09:18:50 +0000 |
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committer | Eric Andersen <andersen@codepoet.org> | 2002-02-20 09:18:50 +0000 |
commit | e356ea321c8098cf1a83a67e27d64c44de08a298 (patch) | |
tree | 8be9273fb8f0e6acab47a9e09552cfbea5400b31 /libpthread/linuxthreads/spinlock.h | |
parent | 07ebf927b17572d92e785533d6e8ac1668cc57c6 (diff) |
Merge in the pthread library. This is the linuxthreads library taken from
glibc 2.1.3 and ported to work with uClibc by Stefan Soucek and Erik Andersen
(me). Stefan has hacked things up such that linuxthreads runs on MMU-less
systems (tested only on arm-nommu). Erik cleaned things up and made it work
properly as a shared library.
-Erik
Diffstat (limited to 'libpthread/linuxthreads/spinlock.h')
-rw-r--r-- | libpthread/linuxthreads/spinlock.h | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/spinlock.h b/libpthread/linuxthreads/spinlock.h new file mode 100644 index 000000000..aae18a27b --- /dev/null +++ b/libpthread/linuxthreads/spinlock.h @@ -0,0 +1,102 @@ +/* Linuxthreads - a simple clone()-based implementation of Posix */ +/* threads for Linux. */ +/* Copyright (C) 1998 Xavier Leroy (Xavier.Leroy@inria.fr) */ +/* */ +/* This program is free software; you can redistribute it and/or */ +/* modify it under the terms of the GNU Library General Public License */ +/* as published by the Free Software Foundation; either version 2 */ +/* of the License, or (at your option) any later version. */ +/* */ +/* This program 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 Library General Public License for more details. */ + +#if defined(TEST_FOR_COMPARE_AND_SWAP) + +extern int __pthread_has_cas; +extern int __pthread_compare_and_swap(long * ptr, long oldval, long newval, + int * spinlock); + +static inline int compare_and_swap(long * ptr, long oldval, long newval, + int * spinlock) +{ + if (__builtin_expect (__pthread_has_cas, 1)) + return __compare_and_swap(ptr, oldval, newval); + else + return __pthread_compare_and_swap(ptr, oldval, newval, spinlock); +} + +#elif defined(HAS_COMPARE_AND_SWAP) + +static inline int compare_and_swap(long * ptr, long oldval, long newval, + int * spinlock) +{ + return __compare_and_swap(ptr, oldval, newval); +} + +#else + +extern int __pthread_compare_and_swap(long * ptr, long oldval, long newval, + int * spinlock); + +static inline int compare_and_swap(long * ptr, long oldval, long newval, + int * spinlock) +{ + return __pthread_compare_and_swap(ptr, oldval, newval, spinlock); +} + +#endif + +/* Internal locks */ + +extern void internal_function __pthread_lock(struct _pthread_fastlock * lock, + pthread_descr self); +extern void internal_function __pthread_unlock(struct _pthread_fastlock *lock); + +static inline void __pthread_init_lock(struct _pthread_fastlock * lock) +{ + lock->__status = 0; + lock->__spinlock = 0; +} + +static inline int __pthread_trylock (struct _pthread_fastlock * lock) +{ + long oldstatus; + + do { + oldstatus = lock->__status; + if (oldstatus != 0) return EBUSY; + } while(! compare_and_swap(&lock->__status, 0, 1, &lock->__spinlock)); + return 0; +} + +#define LOCK_INITIALIZER {0, 0} + +/* Operations on pthread_atomic, which is defined in internals.h */ + +static inline long atomic_increment(struct pthread_atomic *pa) +{ + long oldval; + + do { + oldval = pa->p_count; + } while (!compare_and_swap(&pa->p_count, oldval, oldval + 1, &pa->p_spinlock)); + + return oldval; +} + + +static inline long atomic_decrement(struct pthread_atomic *pa) +{ + long oldval; + + do { + oldval = pa->p_count; + } while (!compare_and_swap(&pa->p_count, oldval, oldval - 1, &pa->p_spinlock)); + + return oldval; +} + +#define ATOMIC_INITIALIZER { 0, 0 } + |