diff options
Diffstat (limited to 'erts/include/internal/pthread/ethr_event.h')
| -rw-r--r-- | erts/include/internal/pthread/ethr_event.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/erts/include/internal/pthread/ethr_event.h b/erts/include/internal/pthread/ethr_event.h new file mode 100644 index 0000000000..104ec287e0 --- /dev/null +++ b/erts/include/internal/pthread/ethr_event.h @@ -0,0 +1,151 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2009-2010. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ + +/* + * Author: Rickard Green + */ + +#if defined(ETHR_HAVE_LINUX_FUTEX) && defined(ETHR_HAVE_NATIVE_ATOMICS) +/* --- Linux futex implementation of ethread events ------------------------- */ +#define ETHR_LINUX_FUTEX_IMPL__ + +#include <sys/syscall.h> +#include <unistd.h> +#include <linux/futex.h> +#include <sys/time.h> + +/* + * Note: Linux futexes operate on 32-bit integers, but + * ethr_native_atomic_t are 64-bits on 64-bit + * platforms. This has to be taken into account. + * Therefore, in each individual value used each + * byte look the same. + */ + +#if ETHR_SIZEOF_PTR == 8 + +#define ETHR_EVENT_OFF_WAITER__ 0xffffffffffffffffL +#define ETHR_EVENT_OFF__ 0x7777777777777777L +#define ETHR_EVENT_ON__ 0L + +#elif ETHR_SIZEOF_PTR == 4 + +#define ETHR_EVENT_OFF_WAITER__ 0xffffffffL +#define ETHR_EVENT_OFF__ 0x77777777L +#define ETHR_EVENT_ON__ 0L + +#else + +#error ehrm... + +#endif + +#if defined(FUTEX_WAIT_PRIVATE) && defined(FUTEX_WAKE_PRIVATE) +# define ETHR_FUTEX_WAIT__ FUTEX_WAIT_PRIVATE +# define ETHR_FUTEX_WAKE__ FUTEX_WAKE_PRIVATE +#else +# define ETHR_FUTEX_WAIT__ FUTEX_WAIT +# define ETHR_FUTEX_WAKE__ FUTEX_WAKE +#endif + +typedef struct { + ethr_atomic_t futex; +} ethr_event; + +#define ETHR_FUTEX__(FTX, OP, VAL) \ + (-1 == syscall(__NR_futex, (void *) (FTX), (OP), (int) (VAL), NULL, NULL, 0)\ + ? errno : 0) + +#if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_EVENT_IMPL__) + +static void ETHR_INLINE +ETHR_INLINE_FUNC_NAME_(ethr_event_set)(ethr_event *e) +{ + long val; + ETHR_WRITE_MEMORY_BARRIER; + val = ethr_atomic_xchg(&e->futex, ETHR_EVENT_ON__); + if (val == ETHR_EVENT_OFF_WAITER__) { + int res = ETHR_FUTEX__(&e->futex, ETHR_FUTEX_WAKE__, 1); + if (res != 0) + ETHR_FATAL_ERROR__(res); + } +} + +static void ETHR_INLINE +ETHR_INLINE_FUNC_NAME_(ethr_event_reset)(ethr_event *e) +{ + ethr_atomic_set(&e->futex, ETHR_EVENT_OFF__); + ETHR_MEMORY_BARRIER; +} + +#endif + +#elif defined(ETHR_PTHREADS) +/* --- Posix mutex/cond implementation of events ---------------------------- */ + +typedef struct { + ethr_atomic_t state; + pthread_mutex_t mtx; + pthread_cond_t cnd; +} ethr_event; + +#define ETHR_EVENT_OFF_WAITER__ -1L +#define ETHR_EVENT_OFF__ 1L +#define ETHR_EVENT_ON__ 0L + +#if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_EVENT_IMPL__) + +static void ETHR_INLINE +ETHR_INLINE_FUNC_NAME_(ethr_event_set)(ethr_event *e) +{ + long val; + ETHR_WRITE_MEMORY_BARRIER; + val = ethr_atomic_xchg(&e->state, ETHR_EVENT_ON__); + if (val == ETHR_EVENT_OFF_WAITER__) { + int res = pthread_mutex_lock(&e->mtx); + if (res != 0) + ETHR_FATAL_ERROR__(res); + res = pthread_cond_signal(&e->cnd); + if (res != 0) + ETHR_FATAL_ERROR__(res); + res = pthread_mutex_unlock(&e->mtx); + if (res != 0) + ETHR_FATAL_ERROR__(res); + } +} + +static void ETHR_INLINE +ETHR_INLINE_FUNC_NAME_(ethr_event_reset)(ethr_event *e) +{ + ethr_atomic_set(&e->state, ETHR_EVENT_OFF__); + ETHR_MEMORY_BARRIER; +} + +#endif + +#endif + +int ethr_event_init(ethr_event *e); +int ethr_event_destroy(ethr_event *e); +int ethr_event_wait(ethr_event *e); +int ethr_event_swait(ethr_event *e, int spincount); +#if !defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_EVENT_IMPL__) +void ethr_event_set(ethr_event *e); +void ethr_event_reset(ethr_event *e); +#endif |