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-rw-r--r--erts/include/internal/pthread/ethr_event.h151
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
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index 0000000000..104ec287e0
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+++ b/erts/include/internal/pthread/ethr_event.h
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+/*
+ * %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