diff options
Diffstat (limited to 'include/atomic/rwlock.h')
| -rw-r--r-- | include/atomic/rwlock.h | 70 |
1 files changed, 59 insertions, 11 deletions
diff --git a/include/atomic/rwlock.h b/include/atomic/rwlock.h index 0ff4d16c545..a31f8ed6ca1 100644 --- a/include/atomic/rwlock.h +++ b/include/atomic/rwlock.h @@ -1,7 +1,7 @@ #ifndef ATOMIC_RWLOCK_INCLUDED #define ATOMIC_RWLOCK_INCLUDED -/* Copyright (C) 2006 MySQL AB +/* Copyright (C) 2006 MySQL AB, 2009 Sun Microsystems, Inc. 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 @@ -16,7 +16,7 @@ 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_rwlock_t rw;} my_atomic_rwlock_t; +#define MY_ATOMIC_MODE_RWLOCKS 1 #ifdef MY_ATOMIC_MODE_DUMMY /* @@ -26,6 +26,9 @@ typedef struct {pthread_rwlock_t rw;} my_atomic_rwlock_t; 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 + +typedef char my_atomic_rwlock_t; + #define my_atomic_rwlock_destroy(name) #define my_atomic_rwlock_init(name) #define my_atomic_rwlock_rdlock(name) @@ -33,18 +36,63 @@ typedef struct {pthread_rwlock_t rw;} my_atomic_rwlock_t; #define my_atomic_rwlock_rdunlock(name) #define my_atomic_rwlock_wrunlock(name) #define MY_ATOMIC_MODE "dummy (non-atomic)" -#else -#define my_atomic_rwlock_destroy(name) pthread_rwlock_destroy(& (name)->rw) -#define my_atomic_rwlock_init(name) pthread_rwlock_init(& (name)->rw, 0) -#define my_atomic_rwlock_rdlock(name) pthread_rwlock_rdlock(& (name)->rw) -#define my_atomic_rwlock_wrlock(name) pthread_rwlock_wrlock(& (name)->rw) -#define my_atomic_rwlock_rdunlock(name) pthread_rwlock_unlock(& (name)->rw) -#define my_atomic_rwlock_wrunlock(name) pthread_rwlock_unlock(& (name)->rw) -#define MY_ATOMIC_MODE "rwlocks" +#else /* not MY_ATOMIC_MODE_DUMMY */ + +typedef struct {pthread_mutex_t rw;} my_atomic_rwlock_t; + +#ifndef SAFE_MUTEX + +/* + 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) + +#else /* SAFE_MUTEX */ + +/* + SAFE_MUTEX pollutes the compiling name space with macros + that alter pthread_mutex_t, pthread_mutex_init, etc. + Atomic operations should never use the safe mutex wrappers. + Unfortunately, there is no way to have both: + - safe mutex macros expanding pthread_mutex_lock to safe_mutex_lock + - my_atomic macros expanding to unmodified pthread_mutex_lock + inlined in the same compilation unit. + So, in case of SAFE_MUTEX, a function call is required. + Given that SAFE_MUTEX is a debugging facility, + this extra function call is not a performance concern for + production builds. +*/ +C_MODE_START +extern void plain_pthread_mutex_init(safe_mutex_t *); +extern void plain_pthread_mutex_destroy(safe_mutex_t *); +extern void plain_pthread_mutex_lock(safe_mutex_t *); +extern void plain_pthread_mutex_unlock(safe_mutex_t *); +C_MODE_END + +#define my_atomic_rwlock_destroy(name) plain_pthread_mutex_destroy(&(name)->rw) +#define my_atomic_rwlock_init(name) plain_pthread_mutex_init(&(name)->rw) +#define my_atomic_rwlock_rdlock(name) plain_pthread_mutex_lock(&(name)->rw) +#define my_atomic_rwlock_wrlock(name) plain_pthread_mutex_lock(&(name)->rw) +#define my_atomic_rwlock_rdunlock(name) plain_pthread_mutex_unlock(&(name)->rw) +#define my_atomic_rwlock_wrunlock(name) plain_pthread_mutex_unlock(&(name)->rw) + +#endif /* SAFE_MUTEX */ + +#define MY_ATOMIC_MODE "mutex" +#ifndef MY_ATOMIC_MODE_RWLOCKS +#define MY_ATOMIC_MODE_RWLOCKS 1 +#endif #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_fas_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; |