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authorRoland McGrath <roland@gnu.org>2003-03-22 23:01:01 +0000
committerRoland McGrath <roland@gnu.org>2003-03-22 23:01:01 +0000
commitd15851ec24d31ccf3ee9a4a388104974d1f494dc (patch)
tree6ad9a310067d563e20b58cd275fac04cdea53c04 /include/atomic.h
parent38ed16cf8860812f4f18d19a69fc031ab9da1156 (diff)
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* include/atomic.h (atomic_increment_and_test): Invert sense of test.
	Add comment.
	(atomic_decrement_and_test): Add comment.

2003-03-22  Jakub Jelinek  <jakub@redhat.com>

	* include/atomic.h (atomic_compare_and_exchange_val_acq): Add comment.
	Don't define if __arch_compare_and_exchange_val_32_acq is not defined.
	(atomic_compare_and_exchange_bool_acq): Add comment.  Don't use
	__oldval variable in the macro, since it might be macro argument.
	(atomic_decrement_if_positive): Initialize __memp, remove setting
	of non-existent variable.
	(atomic_bit_test_set): Cast 1 to __typeof (*mem) before shifting.
	* sysdeps/ia64/bits/atomic.h (atomic_exchange_and_add): Implement
	using atomic_compare_and_exchange_val_acq.
	(atomic_decrement_if_positive, atomic_bit_test_set): Define.
	* sysdeps/s390/bits/atomic.h (__arch_compare_and_exchange_val_8_acq):
	Renamed from...
	(__arch_compare_and_exchange_bool_8_acq): ... this.
	(__arch_compare_and_exchange_val_16_acq): Renamed from...
	(__arch_compare_and_exchange_bool_16_acq): ... this.
	(__arch_compare_and_exchange_val_32_acq): Return old value.  Renamed
	from...
	(__arch_compare_and_exchange_bool_32_acq): ... this.
	(__arch_compare_and_exchange_val_64_acq): Return old value.  Renamed
	from...
	(__arch_compare_and_exchange_bool_64_acq): ... this.
	(__arch_compare_and_exchange_val_32_acq): Use __typeof for local
	variables types instead of assuming int.
	Change prefix of local variables to __arch.
	* sysdeps/generic/bits/atomic.h (arch_compare_and_exchange_acq):
	Remove.
	(atomic_compare_and_exchange_val_acq,
	atomic_compare_and_exchange_bool_acq): Define.

	* csu/tst-atomic.c: New test.
	* csu/tst-atomic-long.c: New test.
	* csu/Makefile (tests): Add tst-atomic and tst-atomic-long.

	* malloc/memusagestat.c (main): Kill warning if uint64_t is ulong.

	* sysdeps/s390/Versions: Add trailing newline.

	* sysdeps/unix/sysv/linux/sysconf.c (__sysconf): Kill warning
	if INTERNAL_SYSCALL_ERROR_P doesn't use its first argument.
Diffstat (limited to 'include/atomic.h')
-rw-r--r--include/atomic.h25
1 files changed, 17 insertions, 8 deletions
diff --git a/include/atomic.h b/include/atomic.h
index 017a8455d7..9469866ebe 100644
--- a/include/atomic.h
+++ b/include/atomic.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+/* Internal macros for atomic operations for GNU C Library.
+   Copyright (C) 2002, 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -25,7 +26,10 @@
 #include <bits/atomic.h>
 
 
-#ifndef atomic_compare_and_exchange_val_acq
+/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
+   Return the old *MEM value.  */
+#if !defined atomic_compare_and_exchange_val_acq \
+    && defined __arch_compare_and_exchange_val_32_acq
 # define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
   ({ __typeof (*mem) __result;						      \
      if (sizeof (*mem) == 1)						      \
@@ -48,6 +52,8 @@
 #endif
 
 
+/* Atomically store NEWVAL in *MEM if *MEM is equal to OLDVAL.
+   Return zero if *MEM was changed or non-zero if no exchange happened.  */
 #ifndef atomic_compare_and_exchange_bool_acq
 # ifdef __arch_compare_and_exchange_bool_32_acq
 #  define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
@@ -69,8 +75,10 @@
      __result; })
 # else
 #  define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
-  ({ __typeof (oldval) __oldval = (oldval);				      \
-     atomic_compare_and_exchange_val_acq (mem, newval, __oldval) != __oldval; \
+  ({ /* Cannot use __oldval here, because macros later in this file might     \
+	call this macro with __oldval argument.	 */			      \
+     __typeof (oldval) __old = (oldval);				      \
+     atomic_compare_and_exchange_val_acq (mem, newval, __old) != __old;	      \
   })
 # endif
 #endif
@@ -129,9 +137,10 @@
 #endif
 
 
+/* Add one to *MEM and return true iff it's now nonzero.  */
 #ifndef atomic_increment_and_test
 # define atomic_increment_and_test(mem) \
-  (atomic_exchange_and_add (mem, 1) == 0)
+  (atomic_exchange_and_add (mem, 1) != 0)
 #endif
 
 
@@ -140,6 +149,7 @@
 #endif
 
 
+/* Subtract 1 from *MEM and return true iff it's now zero.  */
 #ifndef atomic_decrement_and_test
 # define atomic_decrement_and_test(mem) \
   (atomic_exchange_and_add (mem, -1) == 0)
@@ -150,9 +160,8 @@
 #ifndef atomic_decrement_if_positive
 # define atomic_decrement_if_positive(mem) \
   ({ __typeof (*mem) __oldval;						      \
-     __typeof (mem) __memp;						      \
+     __typeof (mem) __memp = (mem);					      \
 									      \
-     __val = *__memp;							      \
      do									      \
        {								      \
 	 __oldval = *__memp;						      \
@@ -190,7 +199,7 @@
 # define atomic_bit_test_set(mem, bit) \
   ({ __typeof (*mem) __oldval;						      \
      __typeof (mem) __memp = (mem);					      \
-     __typeof (*mem) __mask = (1 << (bit));				      \
+     __typeof (*mem) __mask = ((__typeof (*mem)) 1 << (bit));		      \
 									      \
      do									      \
        __oldval = (*__memp);						      \