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/* Copyright (C) 2006 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
typedef struct {pthread_mutex_t rw;} my_atomic_rwlock_t;
#ifdef MY_ATOMIC_MODE_DUMMY
/*
the following can never be enabled by ./configure, one need to put #define in
a source to trigger the following warning. The resulting code will be broken,
it only makes sense to do it to see now test_atomic detects broken
implementations (another way is to run a UP build on an SMP box).
*/
#warning MY_ATOMIC_MODE_DUMMY and MY_ATOMIC_MODE_RWLOCKS are incompatible
#define my_atomic_rwlock_destroy(name)
#define my_atomic_rwlock_init(name)
#define my_atomic_rwlock_rdlock(name)
#define my_atomic_rwlock_wrlock(name)
#define my_atomic_rwlock_rdunlock(name)
#define my_atomic_rwlock_wrunlock(name)
#define MY_ATOMIC_MODE "dummy (non-atomic)"
#else
/*
we're using read-write lock macros but map them to mutex locks, and they're
faster. Still, having semantically rich API we can change the
underlying implementation, if necessary.
*/
#define my_atomic_rwlock_destroy(name) pthread_mutex_destroy(& (name)->rw)
#define my_atomic_rwlock_init(name) pthread_mutex_init(& (name)->rw, 0)
#define my_atomic_rwlock_rdlock(name) pthread_mutex_lock(& (name)->rw)
#define my_atomic_rwlock_wrlock(name) pthread_mutex_lock(& (name)->rw)
#define my_atomic_rwlock_rdunlock(name) pthread_mutex_unlock(& (name)->rw)
#define my_atomic_rwlock_wrunlock(name) pthread_mutex_unlock(& (name)->rw)
#define MY_ATOMIC_MODE "mutex"
#endif
#define make_atomic_add_body(S) int ## S sav; sav= *a; *a+= v; v=sav;
#define make_atomic_swap_body(S) int ## S sav; sav= *a; *a= v; v=sav;
#define make_atomic_cas_body(S) if ((ret= (*a == *cmp))) *a= set; else *cmp=*a;
#define make_atomic_load_body(S) ret= *a;
#define make_atomic_store_body(S) *a= v;
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