X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fovs-thread.h;h=b6d973f6e46beffd20f107970988d4eb5474ed24;hb=4b0424809b823101c969a0691fc1db0c880ae64a;hp=9b8eeef3702e3ead1bfe28f41b1d9dcfd53ecdff;hpb=7aaeab4df24b7e9460705b1dad1010eef0354c50;p=sliver-openvswitch.git diff --git a/lib/ovs-thread.h b/lib/ovs-thread.h index 9b8eeef37..b6d973f6e 100644 --- a/lib/ovs-thread.h +++ b/lib/ovs-thread.h @@ -30,38 +30,11 @@ struct OVS_LOCKABLE ovs_mutex { const char *where; }; -/* "struct ovs_mutex" initializers: - * - * - OVS_MUTEX_INITIALIZER: common case. - * - * - OVS_ADAPTIVE_MUTEX_INITIALIZER for a mutex that spins briefly then goes - * to sleeps after some number of iterations. - * - * - OVS_ERRORCHECK_MUTEX_INITIALIZER for a mutex that is used for - * error-checking. */ -#define OVS_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, NULL } -#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP -#define OVS_ADAPTIVE_MUTEX_INITIALIZER \ - { PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP, NULL } -#else -#define OVS_ADAPTIVE_MUTEX_INITIALIZER OVS_MUTEX_INITIALIZER -#endif +/* "struct ovs_mutex" initializer. */ #ifdef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP -#define OVS_ERRORCHECK_MUTEX_INITIALIZER \ - { PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, NULL } -#else -#define OVS_ERRORCHECK_MUTEX_INITIALIZER OVS_MUTEX_INITIALIZER -#endif - -/* Mutex types, suitable for use with pthread_mutexattr_settype(). - * There is only one nonstandard type: - * - * - PTHREAD_MUTEX_ADAPTIVE_NP, the type used for - * OVS_ADAPTIVE_MUTEX_INITIALIZER. */ -#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP -#define OVS_MUTEX_ADAPTIVE PTHREAD_MUTEX_ADAPTIVE_NP +#define OVS_MUTEX_INITIALIZER { PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, NULL } #else -#define OVS_MUTEX_ADAPTIVE PTHREAD_MUTEX_NORMAL +#define OVS_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, NULL } #endif /* ovs_mutex functions analogous to pthread_mutex_*() functions. @@ -69,7 +42,8 @@ struct OVS_LOCKABLE ovs_mutex { * Most of these functions abort the process with an error message on any * error. ovs_mutex_trylock() is an exception: it passes through a 0 or EBUSY * return value to the caller and aborts on any other error. */ -void ovs_mutex_init(const struct ovs_mutex *, int type); +void ovs_mutex_init(const struct ovs_mutex *); +void ovs_mutex_init_recursive(const struct ovs_mutex *); void ovs_mutex_destroy(const struct ovs_mutex *); void ovs_mutex_unlock(const struct ovs_mutex *mutex) OVS_RELEASES(mutex); void ovs_mutex_lock_at(const struct ovs_mutex *mutex, const char *where) @@ -116,7 +90,7 @@ void ovs_rwlock_unlock(const struct ovs_rwlock *rwlock) OVS_RELEASES(rwlock); void ovs_rwlock_wrlock_at(const struct ovs_rwlock *rwlock, const char *where) OVS_ACQ_WRLOCK(rwlock); #define ovs_rwlock_wrlock(rwlock) \ - ovs_rwlock_wrlock_at(rwlock, SOURCE_LOCATOR); + ovs_rwlock_wrlock_at(rwlock, SOURCE_LOCATOR) int ovs_rwlock_trywrlock_at(const struct ovs_rwlock *rwlock, const char *where) OVS_TRY_WRLOCK(0, rwlock); @@ -126,7 +100,7 @@ int ovs_rwlock_trywrlock_at(const struct ovs_rwlock *rwlock, const char *where) void ovs_rwlock_rdlock_at(const struct ovs_rwlock *rwlock, const char *where) OVS_ACQ_RDLOCK(rwlock); #define ovs_rwlock_rdlock(rwlock) \ - ovs_rwlock_rdlock_at(rwlock, SOURCE_LOCATOR); + ovs_rwlock_rdlock_at(rwlock, SOURCE_LOCATOR) int ovs_rwlock_tryrdlock_at(const struct ovs_rwlock *rwlock, const char *where) OVS_TRY_RDLOCK(0, rwlock); @@ -153,8 +127,10 @@ void xpthread_cond_broadcast(pthread_cond_t *); #endif void xpthread_key_create(pthread_key_t *, void (*destructor)(void *)); +void xpthread_setspecific(pthread_key_t, const void *); void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); +void xpthread_join(pthread_t, void **); /* Per-thread data. * @@ -192,7 +168,15 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); * cross-thread access? yes no yes */ -/* DEFINE_PER_THREAD_DATA(TYPE, NAME, INITIALIZER). +/* For static data, use this macro in a source file: + * + * DEFINE_STATIC_PER_THREAD_DATA(TYPE, NAME, INITIALIZER). + * + * For global data, "declare" the data in the header and "define" it in + * the source file, with: + * + * DECLARE_EXTERN_PER_THREAD_DATA(TYPE, NAME). + * DEFINE_EXTERN_PER_THREAD_DATA(NAME, INITIALIZER). * * One should prefer to use POSIX per-thread data, via pthread_key_t, when its * performance is acceptable, because of its portability (see the table above). @@ -230,23 +214,40 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); #error #endif -#define DEFINE_PER_THREAD_DATA(TYPE, NAME, ...) \ - typedef TYPE NAME##_type; \ - static thread_local NAME##_type NAME##_var = __VA_ARGS__; \ - \ - static NAME##_type * \ - NAME##_get_unsafe(void) \ - { \ - return &NAME##_var; \ - } \ - \ - static NAME##_type * \ - NAME##_get(void) \ - { \ - return NAME##_get_unsafe(); \ +#define DEFINE_STATIC_PER_THREAD_DATA(TYPE, NAME, ...) \ + typedef TYPE NAME##_type; \ + \ + static NAME##_type * \ + NAME##_get_unsafe(void) \ + { \ + static thread_local NAME##_type var = __VA_ARGS__; \ + return &var; \ + } \ + \ + static NAME##_type * \ + NAME##_get(void) \ + { \ + return NAME##_get_unsafe(); \ + } +#define DECLARE_EXTERN_PER_THREAD_DATA(TYPE, NAME) \ + typedef TYPE NAME##_type; \ + extern thread_local NAME##_type NAME##_var; \ + \ + static inline NAME##_type * \ + NAME##_get_unsafe(void) \ + { \ + return &NAME##_var; \ + } \ + \ + static inline NAME##_type * \ + NAME##_get(void) \ + { \ + return NAME##_get_unsafe(); \ } +#define DEFINE_EXTERN_PER_THREAD_DATA(NAME, ...) \ + thread_local NAME##_type NAME##_var = __VA_ARGS__; #else /* no C implementation support for thread-local storage */ -#define DEFINE_PER_THREAD_DATA(TYPE, NAME, ...) \ +#define DEFINE_STATIC_PER_THREAD_DATA(TYPE, NAME, ...) \ typedef TYPE NAME##_type; \ static pthread_key_t NAME##_key; \ \ @@ -275,9 +276,52 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); if (!value) { \ static const NAME##_type initial_value = __VA_ARGS__; \ \ - value = xmalloc(sizeof *value); \ + value = malloc(sizeof *value); \ + if (value == NULL) { \ + out_of_memory(); \ + } \ *value = initial_value; \ - pthread_setspecific(NAME##_key, value); \ + xpthread_setspecific(NAME##_key, value); \ + } \ + return value; \ + } +#define DECLARE_EXTERN_PER_THREAD_DATA(TYPE, NAME) \ + typedef TYPE NAME##_type; \ + static pthread_key_t NAME##_key; \ + \ + static inline NAME##_type * \ + NAME##_get_unsafe(void) \ + { \ + return pthread_getspecific(NAME##_key); \ + } \ + \ + NAME##_type *NAME##_get(void); +#define DEFINE_EXTERN_PER_THREAD_DATA(NAME, ...) \ + static void \ + NAME##_once_init(void) \ + { \ + if (pthread_key_create(&NAME##_key, free)) { \ + abort(); \ + } \ + } \ + \ + NAME##_type * \ + NAME##_get(void) \ + { \ + static pthread_once_t once = PTHREAD_ONCE_INIT; \ + NAME##_type *value; \ + \ + pthread_once(&once, NAME##_once_init); \ + value = NAME##_get_unsafe(); \ + if (!value) { \ + static const NAME##_type initial_value = __VA_ARGS__; \ + \ + value = malloc(sizeof *value); \ + if (value == NULL) { \ + out_of_memory(); \ + } \ + *value = initial_value; \ + xpthread_setspecific(NAME##_key, value); \ } \ return value; \ } @@ -348,7 +392,7 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); NAME##_set_unsafe(TYPE value) \ { \ TYPE old_value = NAME##_get_unsafe(); \ - pthread_setspecific(NAME##_key, value); \ + xpthread_setspecific(NAME##_key, value); \ return old_value; \ } \ \ @@ -399,19 +443,19 @@ struct ovsthread_once { #define OVSTHREAD_ONCE_INITIALIZER \ { \ ATOMIC_VAR_INIT(false), \ - OVS_ADAPTIVE_MUTEX_INITIALIZER, \ + OVS_MUTEX_INITIALIZER, \ } static inline bool ovsthread_once_start(struct ovsthread_once *once) - OVS_TRY_LOCK(true, &once->mutex); + OVS_TRY_LOCK(true, once->mutex); void ovsthread_once_done(struct ovsthread_once *once) - OVS_RELEASES(&once->mutex); + OVS_RELEASES(once->mutex); bool ovsthread_once_start__(struct ovsthread_once *once) - OVS_TRY_LOCK(false, &once->mutex); + OVS_TRY_LOCK(false, once->mutex); static inline bool -ovsthread_once_is_done__(const struct ovsthread_once *once) +ovsthread_once_is_done__(struct ovsthread_once *once) { bool done; @@ -432,11 +476,23 @@ ovsthread_once_start(struct ovsthread_once *once) return OVS_UNLIKELY(!ovsthread_once_is_done__(once) && !ovsthread_once_start__(once)); } + +/* Thread ID. + * + * pthread_t isn't so nice for some purposes. Its size and representation are + * implementation dependent, which means that there is no way to hash it. + * This thread ID avoids the problem. + */ -#ifdef __CHECKER__ -#define ovsthread_once_start(ONCE) \ - ((ONCE)->done ? false : ({ OVS_MACRO_LOCK((&ONCE->mutex)); true; })) -#endif +DECLARE_EXTERN_PER_THREAD_DATA(unsigned int, ovsthread_id); + +/* Returns a per-thread identifier unique within the lifetime of the + * process. */ +static inline unsigned int +ovsthread_id_self(void) +{ + return *ovsthread_id_get(); +} void assert_single_threaded_at(const char *where); #define assert_single_threaded() assert_single_threaded_at(SOURCE_LOCATOR) @@ -446,5 +502,9 @@ pid_t xfork_at(const char *where); void forbid_forking(const char *reason); bool may_fork(void); + +/* Useful functions related to threading. */ + +int count_cpu_cores(void); #endif /* ovs-thread.h */