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-rw-r--r--libc/sysdeps/linux/common/bits/atomicity.h54
1 files changed, 54 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/bits/atomicity.h b/libc/sysdeps/linux/common/bits/atomicity.h
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index 000000000..1a756498b
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+++ b/libc/sysdeps/linux/common/bits/atomicity.h
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+/* Low-level functions for atomic operations. Stub version.
+ Copyright (C) 1997,2001 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#ifndef _ATOMICITY_H
+#define _ATOMICITY_H 1
+
+#include <inttypes.h>
+
+#warning stub atomicity functions are not really atomic
+
+static inline int
+__attribute__ ((unused))
+exchange_and_add (volatile uint32_t *mem, int val)
+{
+ int result = *mem;
+ *mem += val;
+ return result;
+}
+
+static inline void
+__attribute__ ((unused))
+atomic_add (volatile uint32_t *mem, int val)
+{
+ *mem += val;
+}
+
+static inline int
+__attribute__ ((unused))
+compare_and_swap (volatile long int *p, long int oldval, long int newval)
+{
+ if (*p != oldval)
+ return 0;
+
+ *p = newval;
+ return 1;
+}
+
+#endif /* atomicity.h */