Use generic lock-free queue for async threads

Queues used for communication between async threads and scheduler threads
have been replaced with lock-free queues.

Drivers using the driver_async functionality are not automatically locked
to the system anymore, and can be unloaded as any dynamically linked in
driver.

Scheduling of ready async jobs is now also interleaved in between other
jobs. Previously all ready async jobs was performed at once.

1 files changed, 66 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_async.h b/erts/emulator/beam/erl_async.h
new file mode 100644
index 0000000000..95374a8fc9
--- /dev/null
+++ b/erts/emulator/beam/erl_async.h
@@ -0,0 +1,66 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2011. 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%
+ */
+
+#ifndef ERL_ASYNC_H__
+#define ERL_ASYNC_H__
+
+#define ERTS_MAX_NO_OF_ASYNC_THREADS 1024
+extern int erts_async_max_threads;
+#define ERTS_ASYNC_THREAD_MIN_STACK_SIZE 16	/* Kilo words */
+#define ERTS_ASYNC_THREAD_MAX_STACK_SIZE 8192	/* Kilo words */
+extern int erts_async_thread_suggested_stack_size;
+
+#ifdef USE_THREADS
+
+#ifdef ERTS_SMP
+/*
+ * With smp support we can choose to have, or not to
+ * have an async ready queue.
+ */
+#define ERTS_USE_ASYNC_READY_Q 1
+#endif
+
+#ifndef ERTS_SMP
+/* In non-smp case we *need* the async ready queue */
+#  undef ERTS_USE_ASYNC_READY_Q
+#  define ERTS_USE_ASYNC_READY_Q 1
+#endif
+
+#ifndef ERTS_USE_ASYNC_READY_Q
+#  define ERTS_USE_ASYNC_READY_Q 0
+#endif
+
+#if ERTS_USE_ASYNC_READY_Q
+int erts_check_async_ready(void *);
+int erts_async_ready_clean(void *, void *);
+void *erts_get_async_ready_queue(Uint sched_id);
+#define ERTS_ASYNC_READY_CLEAN 0
+#define ERTS_ASYNC_READY_DIRTY 1
+#ifdef ERTS_SMP
+#define ERTS_ASYNC_READY_NEED_THR_PRGR 2
+#endif
+#endif /* ERTS_USE_ASYNC_READY_Q */
+
+#endif /* USE_THREADS */
+
+void erts_init_async(void);
+void erts_exit_flush_async(void);
+
+
+#endif /* ERL_ASYNC_H__ */