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authorRickard Green <[email protected]>2010-06-01 13:51:34 +0000
committerErlang/OTP <[email protected]>2010-06-01 13:51:34 +0000
commitc68f1802ce375c3425795671c74c6b3fd9c3a8ef (patch)
treeb2fbb14797c866cc1470f85dbc6382cf586150d4 /erts
parentb53f8a67649a371a38dc6d97b0dfe52111236a3e (diff)
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OTP-8659 Add ethread support for gcc atomics
Support for using gcc's built-in functions for atomic memory access has been added. This functionallity will be used if available and no other native atomic implementation in ERTS is available.
Diffstat (limited to 'erts')
-rw-r--r--erts/aclocal.m428
-rw-r--r--erts/include/internal/ethread.h40
-rw-r--r--erts/include/internal/ethread_header_config.h.in16
-rw-r--r--erts/include/internal/gcc/ethr_atomic.h164
-rw-r--r--erts/include/internal/gcc/ethread.h30
-rw-r--r--erts/lib_src/Makefile.in2
6 files changed, 258 insertions, 22 deletions
diff --git a/erts/aclocal.m4 b/erts/aclocal.m4
index 3d935b7295..6a92fa5653 100644
--- a/erts/aclocal.m4
+++ b/erts/aclocal.m4
@@ -843,6 +843,23 @@ case "$THR_LIB_NAME" in
AC_DEFINE(ETHR_HAVE_PTHREAD_ATTR_SETGUARDSIZE, 1, \
[Define if you have the pthread_attr_setguardsize function.]))
+ AC_MSG_CHECKING([for GCC atomic operations])
+ ethr_have_gcc_atomic_ops=no
+ AC_TRY_LINK([],
+ [
+ long res;
+ volatile long val;
+ res = __sync_val_compare_and_swap(&val, (long) 1, (long) 0);
+ res = __sync_add_and_fetch(&val, (long) 1);
+ res = __sync_sub_and_fetch(&val, (long) 1);
+ res = __sync_fetch_and_and(&val, (long) 1);
+ res = __sync_fetch_and_or(&val, (long) 1);
+ ],
+ [ethr_have_native_atomics=yes
+ ethr_have_gcc_atomic_ops=yes])
+ AC_MSG_RESULT([$ethr_have_gcc_atomic_ops])
+ test $ethr_have_gcc_atomic_ops = yes && AC_DEFINE(ETHR_HAVE_GCC_ATOMIC_OPS, 1, [Define if you have gcc atomic operations])
+
dnl Restore LIBS
LIBS=$saved_libs
dnl restore CPPFLAGS
@@ -873,6 +890,17 @@ if test "X$disable_native_ethr_impls" = "Xyes"; then
AC_DEFINE(ETHR_DISABLE_NATIVE_IMPLS, 1, [Define if you want to disable native ethread implementations])
fi
+AC_ARG_ENABLE(prefer-gcc-native-ethr-impls,
+ AS_HELP_STRING([--enable-prefer-gcc-native-ethr-impls],
+ [enable prefer gcc native ethread implementations]),
+[ case "$enableval" in
+ yes) enable_prefer_gcc_native_ethr_impls=yes ;;
+ *) enable_prefer_gcc_native_ethr_impls=no ;;
+ esac ], enable_prefer_gcc_native_ethr_impls=no)
+
+test $enable_prefer_gcc_native_ethr_impls = yes &&
+ AC_DEFINE(ETHR_PREFER_GCC_NATIVE_IMPLS, 1, [Define if you prefer gcc native ethread implementations])
+
AC_DEFINE(ETHR_HAVE_ETHREAD_DEFINES, 1, \
[Define if you have all ethread defines])
diff --git a/erts/include/internal/ethread.h b/erts/include/internal/ethread.h
index 564f8f057c..9921247a06 100644
--- a/erts/include/internal/ethread.h
+++ b/erts/include/internal/ethread.h
@@ -694,25 +694,33 @@ ETHR_INLINE_FUNC_NAME_(ethr_write_lock)(ethr_rwlock_t *lock)
#endif
/* For CPU-optimised atomics, spinlocks, and rwlocks. */
-#if !defined(ETHR_DISABLE_NATIVE_IMPLS) && defined(__GNUC__)
-# if ETHR_SIZEOF_PTR == 4
-# if defined(__i386__)
-# include "i386/ethread.h"
-# elif (defined(__powerpc__) || defined(__ppc__)) && !defined(__powerpc64__)
-# include "ppc32/ethread.h"
-# elif defined(__sparc__)
-# include "sparc32/ethread.h"
-# elif defined(__tile__)
-# include "tile/ethread.h"
+#if !defined(ETHR_DISABLE_NATIVE_IMPLS)
+# if defined(__GNUC__)
+# if defined(ETHR_PREFER_GCC_NATIVE_IMPLS)
+# include "gcc/ethread.h"
# endif
-# elif ETHR_SIZEOF_PTR == 8
-# if defined(__x86_64__)
-# include "x86_64/ethread.h"
-# elif defined(__sparc__) && defined(__arch64__)
-# include "sparc64/ethread.h"
+# ifndef ETHR_HAVE_NATIVE_ATOMICS
+# if ETHR_SIZEOF_PTR == 4
+# if defined(__i386__)
+# include "i386/ethread.h"
+# elif (defined(__powerpc__)||defined(__ppc__))&&!defined(__powerpc64__)
+# include "ppc32/ethread.h"
+# elif defined(__sparc__)
+# include "sparc32/ethread.h"
+# elif defined(__tile__)
+# include "tile/ethread.h"
+# endif
+# elif ETHR_SIZEOF_PTR == 8
+# if defined(__x86_64__)
+# include "x86_64/ethread.h"
+# elif defined(__sparc__) && defined(__arch64__)
+# include "sparc64/ethread.h"
+# endif
+# endif
+# include "gcc/ethread.h"
# endif
# endif
-#endif /* !defined(ETHR_DISABLE_NATIVE_IMPLS) && defined(__GNUC__) */
+#endif /* !defined(ETHR_DISABLE_NATIVE_IMPLS) */
#ifdef ETHR_HAVE_OPTIMIZED_ATOMIC_OPS
# undef ETHR_HAVE_NATIVE_ATOMICS
diff --git a/erts/include/internal/ethread_header_config.h.in b/erts/include/internal/ethread_header_config.h.in
index e5b4946a53..cf25ad3f55 100644
--- a/erts/include/internal/ethread_header_config.h.in
+++ b/erts/include/internal/ethread_header_config.h.in
@@ -1,19 +1,19 @@
/*
* %CopyrightBegin%
- *
- * Copyright Ericsson AB 2004-2009. All Rights Reserved.
- *
+ *
+ * Copyright Ericsson AB 2004-2010. 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%
*/
@@ -50,6 +50,12 @@
/* Define if you have a pthread_rwlock implementation that can be used */
#undef ETHR_HAVE_PTHREAD_RWLOCK_INIT
+/* Define if you have gcc atomic operations */
+#undef ETHR_HAVE_GCC_ATOMIC_OPS
+
+/* Define if you prefer gcc native ethread implementations */
+#undef ETHR_PREFER_GCC_NATIVE_IMPLS
+
/* Define if you want to turn on extra sanity checking in the ethread library */
#undef ETHR_XCHK
diff --git a/erts/include/internal/gcc/ethr_atomic.h b/erts/include/internal/gcc/ethr_atomic.h
new file mode 100644
index 0000000000..775030c8d5
--- /dev/null
+++ b/erts/include/internal/gcc/ethr_atomic.h
@@ -0,0 +1,164 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 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%
+ */
+
+/*
+ * Description: Native atomics ethread support using gcc's builtins
+ * Author: Rickard Green
+ */
+
+#ifndef ETHR_GCC_ATOMIC_H__
+#define ETHR_GCC_ATOMIC_H__
+
+#if !defined(ETHR_HAVE_NATIVE_ATOMICS) && defined(ETHR_HAVE_GCC_ATOMIC_OPS)
+#define ETHR_HAVE_NATIVE_ATOMICS 1
+
+#define ETHR_IMMED_ATOMIC_SET_GET_SAFE__ 0
+/* Enable immediate read/write on platforms where we know it is safe */
+#if defined(__i386__) || defined(__x86_64__) || defined(__sparc__) \
+ || defined(__powerpc__) || defined(__ppc__)
+# undef ETHR_IMMED_ATOMIC_SET_GET_SAFE__
+# define ETHR_IMMED_ATOMIC_SET_GET_SAFE__ 1
+#endif
+
+typedef struct {
+ volatile long counter;
+} ethr_native_atomic_t;
+
+
+/*
+ * According to the documentation this is what we want:
+ * #define ETHR_MEMORY_BARRIER __sync_synchronize()
+ * However, __sync_synchronize() is known to erroneously be
+ * a noop on at least some platforms with some gcc versions.
+ * This has suposedly been fixed in some gcc version, but we
+ * don't know from which version. Therefore, we use the
+ * workaround implemented below on all gcc versions.
+ */
+#define ETHR_MEMORY_BARRIER \
+do { \
+ volatile long x___ = 0; \
+ (void) __sync_val_compare_and_swap(&x___, (long) 0, (long) 1); \
+} while (0)
+
+#if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_AUX_IMPL__)
+
+static ETHR_INLINE void
+ethr_native_atomic_set(ethr_native_atomic_t *var, long value)
+{
+#if ETHR_IMMED_ATOMIC_SET_GET_SAFE__
+ var->counter = value;
+#else
+ /*
+ * Unfortunately no __sync_store() or similar exist in the gcc atomic
+ * op interface. We therefore have to simulate it this way...
+ */
+ long act = 0, exp;
+ do {
+ exp = act;
+ act = __sync_val_compare_and_swap(&var->counter, exp, value);
+ } while (act != exp);
+#endif
+}
+
+#define ethr_native_atomic_init ethr_native_atomic_set
+
+static ETHR_INLINE long
+ethr_native_atomic_read(ethr_native_atomic_t *var)
+{
+#if ETHR_IMMED_ATOMIC_SET_GET_SAFE__
+ return var->counter;
+#else
+ /*
+ * Unfortunately no __sync_fetch() or similar exist in the gcc atomic
+ * op interface. We therefore have to simulate it this way...
+ */
+ return __sync_add_and_fetch(&var->counter, (long) 0);
+#endif
+}
+
+static ETHR_INLINE void
+ethr_native_atomic_add(ethr_native_atomic_t *var, long incr)
+{
+ (void) __sync_add_and_fetch(&var->counter, incr);
+}
+
+static ETHR_INLINE long
+ethr_native_atomic_add_return(ethr_native_atomic_t *var, long incr)
+{
+ return __sync_add_and_fetch(&var->counter, incr);
+}
+
+static ETHR_INLINE void
+ethr_native_atomic_inc(ethr_native_atomic_t *var)
+{
+ (void) __sync_add_and_fetch(&var->counter, (long) 1);
+}
+
+static ETHR_INLINE void
+ethr_native_atomic_dec(ethr_native_atomic_t *var)
+{
+ (void) __sync_sub_and_fetch(&var->counter, (long) 1);
+}
+
+static ETHR_INLINE long
+ethr_native_atomic_inc_return(ethr_native_atomic_t *var)
+{
+ return __sync_add_and_fetch(&var->counter, (long) 1);
+}
+
+static ETHR_INLINE long
+ethr_native_atomic_dec_return(ethr_native_atomic_t *var)
+{
+ return __sync_sub_and_fetch(&var->counter, (long) 1);
+}
+
+static ETHR_INLINE long
+ethr_native_atomic_and_retold(ethr_native_atomic_t *var, long mask)
+{
+ return __sync_fetch_and_and(&var->counter, mask);
+}
+
+static ETHR_INLINE long
+ethr_native_atomic_or_retold(ethr_native_atomic_t *var, long mask)
+{
+ return (long) __sync_fetch_and_or(&var->counter, mask);
+}
+
+static ETHR_INLINE long
+ethr_native_atomic_cmpxchg(ethr_native_atomic_t *var, long new, long old)
+{
+ return __sync_val_compare_and_swap(&var->counter, old, new);
+}
+
+static ETHR_INLINE long
+ethr_native_atomic_xchg(ethr_native_atomic_t *var, long new)
+{
+ long exp, act = 0;
+ do {
+ exp = act;
+ act = __sync_val_compare_and_swap(&var->counter, exp, new);
+ } while (act != exp);
+ return act;
+}
+
+#endif
+
+#endif
+
+#endif
diff --git a/erts/include/internal/gcc/ethread.h b/erts/include/internal/gcc/ethread.h
new file mode 100644
index 0000000000..bb378e31e0
--- /dev/null
+++ b/erts/include/internal/gcc/ethread.h
@@ -0,0 +1,30 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 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%
+ */
+
+/*
+ * Description: Native atomic ethread support when using gcc
+ * Author: Rickard Green
+ */
+
+#ifndef ETHREAD_GCC_H__
+#define ETHREAD_GCC_H__
+
+#include "ethr_atomic.h"
+
+#endif
diff --git a/erts/lib_src/Makefile.in b/erts/lib_src/Makefile.in
index 49f5b1f048..e7caac8072 100644
--- a/erts/lib_src/Makefile.in
+++ b/erts/lib_src/Makefile.in
@@ -447,7 +447,7 @@ INTERNAL_RELEASE_INCLUDES= \
$(ERTS_INCL_INT)/erl_misc_utils.h \
$(ERTS_INCL_INT)/erl_errno.h
-INTERNAL_X_RELEASE_INCLUDE_DIRS= i386 x86_64 ppc32 sparc32 sparc64 tile
+INTERNAL_X_RELEASE_INCLUDE_DIRS= i386 x86_64 ppc32 sparc32 sparc64 tile gcc
INTERNAL_RELEASE_LIBS= \
../lib/internal/README \