From 107d2d5512d6d8a1c43d5aef533e389bf8ba06ad Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Fri, 10 Dec 2010 23:18:08 +0100 Subject: Use 32-bit atomics for events --- erts/include/internal/pthread/ethr_event.h | 54 +++++++++++------------------- erts/lib_src/pthread/ethr_event.c | 30 +++++++++-------- 2 files changed, 35 insertions(+), 49 deletions(-) diff --git a/erts/include/internal/pthread/ethr_event.h b/erts/include/internal/pthread/ethr_event.h index 4cf87406d7..93da8a0429 100644 --- a/erts/include/internal/pthread/ethr_event.h +++ b/erts/include/internal/pthread/ethr_event.h @@ -30,31 +30,9 @@ #include #include -/* - * 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__ ((ethr_sint_t) 0xffffffffffffffffL) -#define ETHR_EVENT_OFF__ ((ethr_sint_t) 0x7777777777777777L) -#define ETHR_EVENT_ON__ ((ethr_sint_t) 0L) - -#elif ETHR_SIZEOF_PTR == 4 - -#define ETHR_EVENT_OFF_WAITER__ ((ethr_sint_t) 0xffffffffL) -#define ETHR_EVENT_OFF__ ((ethr_sint_t) 0x77777777L) -#define ETHR_EVENT_ON__ ((ethr_sint_t) 0L) - -#else - -#error ehrm... - -#endif +#define ETHR_EVENT_OFF_WAITER__ ((ethr_sint32_t) -1) +#define ETHR_EVENT_OFF__ ((ethr_sint32_t) 1) +#define ETHR_EVENT_ON__ ((ethr_sint32_t) 0) #if defined(FUTEX_WAIT_PRIVATE) && defined(FUTEX_WAKE_PRIVATE) # define ETHR_FUTEX_WAIT__ FUTEX_WAIT_PRIVATE @@ -65,11 +43,17 @@ #endif typedef struct { - ethr_atomic_t futex; + ethr_atomic32_t futex; } ethr_event; -#define ETHR_FUTEX__(FTX, OP, VAL) \ - (-1 == syscall(__NR_futex, (void *) (FTX), (OP), (int) (VAL), NULL, NULL, 0)\ +#define ETHR_FUTEX__(FTX, OP, VAL) \ + (-1 == syscall(__NR_futex, \ + (void *) ethr_atomic32_addr((FTX)), \ + (OP), \ + (int) (VAL), \ + NULL, \ + NULL, \ + 0) \ ? errno : 0) #if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_EVENT_IMPL__) @@ -77,9 +61,9 @@ typedef struct { static void ETHR_INLINE ETHR_INLINE_FUNC_NAME_(ethr_event_set)(ethr_event *e) { - ethr_sint_t val; + ethr_sint32_t val; ETHR_WRITE_MEMORY_BARRIER; - val = ethr_atomic_xchg(&e->futex, ETHR_EVENT_ON__); + val = ethr_atomic32_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) @@ -90,7 +74,7 @@ ETHR_INLINE_FUNC_NAME_(ethr_event_set)(ethr_event *e) static void ETHR_INLINE ETHR_INLINE_FUNC_NAME_(ethr_event_reset)(ethr_event *e) { - ethr_atomic_set(&e->futex, ETHR_EVENT_OFF__); + ethr_atomic32_set(&e->futex, ETHR_EVENT_OFF__); ETHR_MEMORY_BARRIER; } @@ -100,7 +84,7 @@ ETHR_INLINE_FUNC_NAME_(ethr_event_reset)(ethr_event *e) /* --- Posix mutex/cond implementation of events ---------------------------- */ typedef struct { - ethr_atomic_t state; + ethr_atomic32_t state; pthread_mutex_t mtx; pthread_cond_t cnd; } ethr_event; @@ -114,9 +98,9 @@ typedef struct { static void ETHR_INLINE ETHR_INLINE_FUNC_NAME_(ethr_event_set)(ethr_event *e) { - ethr_sint_t val; + ethr_sint32_t val; ETHR_WRITE_MEMORY_BARRIER; - val = ethr_atomic_xchg(&e->state, ETHR_EVENT_ON__); + val = ethr_atomic32_xchg(&e->state, ETHR_EVENT_ON__); if (val == ETHR_EVENT_OFF_WAITER__) { int res = pthread_mutex_lock(&e->mtx); if (res != 0) @@ -133,7 +117,7 @@ ETHR_INLINE_FUNC_NAME_(ethr_event_set)(ethr_event *e) static void ETHR_INLINE ETHR_INLINE_FUNC_NAME_(ethr_event_reset)(ethr_event *e) { - ethr_atomic_set(&e->state, ETHR_EVENT_OFF__); + ethr_atomic32_set(&e->state, ETHR_EVENT_OFF__); ETHR_MEMORY_BARRIER; } diff --git a/erts/lib_src/pthread/ethr_event.c b/erts/lib_src/pthread/ethr_event.c index ae1d827731..9434d60d0a 100644 --- a/erts/lib_src/pthread/ethr_event.c +++ b/erts/lib_src/pthread/ethr_event.c @@ -41,7 +41,7 @@ int ethr_event_init(ethr_event *e) { - ethr_atomic_init(&e->futex, ETHR_EVENT_OFF__); + ethr_atomic32_init(&e->futex, ETHR_EVENT_OFF__); return 0; } @@ -56,7 +56,7 @@ wait__(ethr_event *e, int spincount) { unsigned sc = spincount; int res; - ethr_sint_t val; + ethr_sint32_t val; int until_yield = ETHR_YIELD_AFTER_BUSY_LOOPS; if (spincount < 0) @@ -64,7 +64,7 @@ wait__(ethr_event *e, int spincount) while (1) { while (1) { - val = ethr_atomic_read(&e->futex); + val = ethr_atomic32_read(&e->futex); if (val == ETHR_EVENT_ON__) return 0; if (sc == 0) @@ -80,16 +80,18 @@ wait__(ethr_event *e, int spincount) } if (val != ETHR_EVENT_OFF_WAITER__) { - val = ethr_atomic_cmpxchg(&e->futex, - ETHR_EVENT_OFF_WAITER__, - ETHR_EVENT_OFF__); + val = ethr_atomic32_cmpxchg(&e->futex, + ETHR_EVENT_OFF_WAITER__, + ETHR_EVENT_OFF__); if (val == ETHR_EVENT_ON__) return 0; ETHR_ASSERT(val == ETHR_EVENT_OFF__); } - res = ETHR_FUTEX__(&e->futex, ETHR_FUTEX_WAIT__, ETHR_EVENT_OFF_WAITER__); + res = ETHR_FUTEX__(&e->futex, + ETHR_FUTEX_WAIT__, + ETHR_EVENT_OFF_WAITER__); if (res == EINTR) break; if (res != 0 && res != EWOULDBLOCK) @@ -106,7 +108,7 @@ int ethr_event_init(ethr_event *e) { int res; - ethr_atomic_init(&e->state, ETHR_EVENT_OFF__); + ethr_atomic32_init(&e->state, ETHR_EVENT_OFF__); res = pthread_mutex_init(&e->mtx, NULL); if (res != 0) return res; @@ -135,7 +137,7 @@ static ETHR_INLINE int wait__(ethr_event *e, int spincount) { int sc = spincount; - ethr_sint_t val; + ethr_sint32_t val; int res, ulres; int until_yield = ETHR_YIELD_AFTER_BUSY_LOOPS; @@ -143,7 +145,7 @@ wait__(ethr_event *e, int spincount) ETHR_FATAL_ERROR__(EINVAL); while (1) { - val = ethr_atomic_read(&e->state); + val = ethr_atomic32_read(&e->state); if (val == ETHR_EVENT_ON__) return 0; if (sc == 0) @@ -159,9 +161,9 @@ wait__(ethr_event *e, int spincount) } if (val != ETHR_EVENT_OFF_WAITER__) { - val = ethr_atomic_cmpxchg(&e->state, - ETHR_EVENT_OFF_WAITER__, - ETHR_EVENT_OFF__); + val = ethr_atomic32_cmpxchg(&e->state, + ETHR_EVENT_OFF_WAITER__, + ETHR_EVENT_OFF__); if (val == ETHR_EVENT_ON__) return 0; ETHR_ASSERT(val == ETHR_EVENT_OFF__); @@ -176,7 +178,7 @@ wait__(ethr_event *e, int spincount) while (1) { - val = ethr_atomic_read(&e->state); + val = ethr_atomic32_read(&e->state); if (val == ETHR_EVENT_ON__) break; -- cgit v1.2.3