* src/threads/atomic.c: New file.

* src/threads/atomic.hpp: Export generic functions.
* src/threads/Makefile.am (libthreads_la_SOURCES): Added atomic.c.

--HG--
branch : twisti

diff --git a/src/threads/Makefile.am b/src/threads/Makefile.am
index d4b65106e3e48daf609996af7f6268141a7c2990..882901dd6c8b8eb7b1ad03137aa2c0dc3f23777a 100644 (file)
--- a/src/threads/Makefile.am
+++ b/src/threads/Makefile.am
@@ -49,6 +49,7 @@ noinst_LTLIBRARIES = \
 
 if ENABLE_THREADS
 libthreads_la_SOURCES = \
+       atomic.c \
        atomic.hpp \
        critical.c \
        critical.h \

diff --git a/src/threads/atomic.c b/src/threads/atomic.c
new file mode 100644 (file)
index 0000000..49c9722
--- /dev/null
+++ b/src/threads/atomic.c
@@ -0,0 +1,147 @@
+/* src/threads/atomic.cpp - atomic instructions
+
+   Copyright (C) 2008
+   CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
+
+   This file is part of CACAO.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301, USA.
+
+*/
+
+
+#include "config.h"
+
+#include <stdint.h>
+
+#include "threads/atomic.hpp"
+#include "threads/mutex.h"
+
+// Gobal mutex for generic atomic instructions.
+mutex_t lock = MUTEX_INITIALIZER;
+
+
+/**
+ * A generic atomic compare and swap for 32-bit integer values.  This
+ * function is using a mutex to provide atomicity.
+ *
+ * @param p      Pointer to memory address.
+ * @param oldval Old value to be expected.
+ * @param newval New value to be stored.
+ *
+ * @return value of the memory location before the store
+ */
+uint32_t Atomic_generic_compare_and_swap_32(volatile uint32_t *p, uint32_t oldval, uint32_t newval)
+{
+       uint32_t result;
+
+       mutex_lock(&lock);
+
+       // Do the compare-and-swap.
+
+       result = *p;
+
+       if (oldval == result)
+               *p = newval;
+
+       mutex_unlock(&lock);
+
+       return result;
+}
+
+
+/**
+ * A generic atomic compare and swap for 64-bit integer values.  This
+ * function is using a mutex to provide atomicity.
+ *
+ * @param p      Pointer to memory address.
+ * @param oldval Old value to be expected.
+ * @param newval New value to be stored.
+ *
+ * @return value of the memory location before the store
+ */
+uint64_t Atomic_generic_compare_and_swap_64(volatile uint64_t *p, uint64_t oldval, uint64_t newval)
+{
+       uint64_t result;
+
+       mutex_lock(&lock);
+
+       // Do the compare-and-swap.
+
+       result = *p;
+
+       if (oldval == result)
+               *p = newval;
+
+       mutex_unlock(&lock);
+
+       return result;
+}
+
+
+/**
+ * A generic atomic compare and swap for pointer values.  This
+ * function is using a mutex to provide atomicity.
+ *
+ * @param p      Pointer to memory address.
+ * @param oldval Old value to be expected.
+ * @param newval New value to be stored.
+ *
+ * @return value of the memory location before the store
+ */
+void* Atomic_generic_compare_and_swap_ptr(volatile void** p, void* oldval, void* newval)
+{
+       void* result;
+
+       mutex_lock(&lock);
+
+       // Do the compare-and-swap.
+
+       result = (void*) *p;
+
+       if (oldval == result)
+               *p = newval;
+
+       mutex_unlock(&lock);
+
+       return result;
+}
+
+
+/**
+ * A generic memory barrier.  This function is using a mutex to
+ * provide atomicity.
+ */
+void Atomic_generic_memory_barrier(void)
+{
+       mutex_lock(&lock);
+       mutex_unlock(&lock);
+}
+
+
+/*
+ * These are local overrides for various environment variables in Emacs.
+ * Please do not remove this and leave it at the end of the file, where
+ * Emacs will automagically detect them.
+ * ---------------------------------------------------------------------
+ * Local variables:
+ * mode: c++
+ * indent-tabs-mode: t
+ * c-basic-offset: 4
+ * tab-width: 4
+ * End:
+ * vim:noexpandtab:sw=4:ts=4:
+ */

diff --git a/src/threads/atomic.hpp b/src/threads/atomic.hpp
index 02d3133b4caa2375c44478f552f2ff16b14e4677..10937138d686f3af26076b55857d2b938d3f9f54 100644 (file)
--- a/src/threads/atomic.hpp
+++ b/src/threads/atomic.hpp
@@ -30,6 +30,11 @@
 
 #include <stdint.h>
 
+uint32_t Atomic_generic_compare_and_swap_32(volatile uint32_t *p, uint32_t oldval, uint32_t newval);
+uint64_t Atomic_generic_compare_and_swap_64(volatile uint64_t *p, uint64_t oldval, uint64_t newval);
+void*    Atomic_generic_compare_and_swap_ptr(volatile void** p, void* oldval, void* newval);
+void     Atomic_generic_memory_barrier(void);
+
 // Include machine dependent implementation.
 #include "md-atomic.hpp"