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-rw-r--r--include/atomic.h365
1 files changed, 269 insertions, 96 deletions
diff --git a/include/atomic.h b/include/atomic.h
index d44728b215..2ad8b5fcb7 100644
--- a/include/atomic.h
+++ b/include/atomic.h
@@ -21,6 +21,31 @@
 #ifndef _ATOMIC_H
 #define _ATOMIC_H	1
 
+/* This header defines three types of macros:
+
+   - atomic arithmetic and logic operation on memory.  They all
+     have the prefix "atomic_".
+
+   - conditionally atomic operations of the same kinds.  These
+     always behave identical but can be faster when atomicity
+     is not really needed since only one thread has access to
+     the memory location.  In that case the code is slower in
+     the multi-thread case.  The interfaces have the prefix
+     "catomic_".
+
+   - support functions like barriers.  They also have the preifx
+     "atomic_".
+
+   Architectures must provide a few lowlevel macros (the compare
+   and exchange definitions).  All others are optional.  They
+   should only be provided if the architecture has specific
+   support for the operation.
+
+   As <atomic.h> macros are usually heavily nested and often use local
+   variables to make sure side-effects are evaluated properly, use for
+   macro local variables a per-macro unique prefix.  This file uses
+   __atgN_ prefix where N is different in each macro.  */
+
 #include <stdlib.h>
 
 #include <bits/atomic.h>
@@ -30,33 +55,33 @@
    and following args.  */
 #define __atomic_val_bysize(pre, post, mem, ...)			      \
   ({									      \
-    __typeof (*mem) __result;						      \
+    __typeof (*mem) __atg1_result;					      \
     if (sizeof (*mem) == 1)						      \
-      __result = pre##_8_##post (mem, __VA_ARGS__);			      \
+      __atg1_result = pre##_8_##post (mem, __VA_ARGS__);		      \
     else if (sizeof (*mem) == 2)					      \
-      __result = pre##_16_##post (mem, __VA_ARGS__);			      \
+      __atg1_result = pre##_16_##post (mem, __VA_ARGS__);		      \
     else if (sizeof (*mem) == 4)					      \
-      __result = pre##_32_##post (mem, __VA_ARGS__);			      \
+      __atg1_result = pre##_32_##post (mem, __VA_ARGS__);		      \
     else if (sizeof (*mem) == 8)					      \
-      __result = pre##_64_##post (mem, __VA_ARGS__);			      \
+      __atg1_result = pre##_64_##post (mem, __VA_ARGS__);		      \
     else								      \
       abort ();								      \
-    __result;								      \
+    __atg1_result;							      \
   })
 #define __atomic_bool_bysize(pre, post, mem, ...)			      \
   ({									      \
-    int __result;							      \
+    int __atg2_result;							      \
     if (sizeof (*mem) == 1)						      \
-      __result = pre##_8_##post (mem, __VA_ARGS__);			      \
+      __atg2_result = pre##_8_##post (mem, __VA_ARGS__);		      \
     else if (sizeof (*mem) == 2)					      \
-      __result = pre##_16_##post (mem, __VA_ARGS__);			      \
+      __atg2_result = pre##_16_##post (mem, __VA_ARGS__);		      \
     else if (sizeof (*mem) == 4)					      \
-      __result = pre##_32_##post (mem, __VA_ARGS__);			      \
+      __atg2_result = pre##_32_##post (mem, __VA_ARGS__);		      \
     else if (sizeof (*mem) == 8)					      \
-      __result = pre##_64_##post (mem, __VA_ARGS__);			      \
+      __atg2_result = pre##_64_##post (mem, __VA_ARGS__);		      \
     else								      \
       abort ();								      \
-    __result;								      \
+    __atg2_result;							      \
   })
 
 
@@ -70,12 +95,29 @@
 #endif
 
 
+#if !defined catomic_compare_and_exchange_val_acq \
+    && defined __arch_c_compare_and_exchange_val_32_acq
+# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \
+  __atomic_val_bysize (__arch_c_compare_and_exchange_val,acq,		      \
+		       mem, newval, oldval)
+#else
+# define catomic_compare_and_exchange_val_acq(mem, newval, oldval) \
+  atomic_compare_and_exchange_val_acq (mem, newval, oldval)
+#endif
+
+
 #ifndef atomic_compare_and_exchange_val_rel
 # define atomic_compare_and_exchange_val_rel(mem, newval, oldval)	      \
   atomic_compare_and_exchange_val_acq (mem, newval, oldval)
 #endif
 
 
+#ifndef catomic_compare_and_exchange_val_rel
+# define catomic_compare_and_exchange_val_rel(mem, newval, oldval)	      \
+  atomic_compare_and_exchange_val_acq (mem, newval, oldval)
+#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
@@ -87,8 +129,26 @@
 #   define atomic_compare_and_exchange_bool_acq(mem, newval, 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;	      \
+     __typeof (oldval) __atg3_old = (oldval);				      \
+     atomic_compare_and_exchange_val_acq (mem, newval, __atg3_old)	      \
+       != __atg3_old;							      \
+  })
+# endif
+#endif
+
+
+#ifndef catomic_compare_and_exchange_bool_acq
+# ifdef __arch_c_compare_and_exchange_bool_32_acq
+#  define catomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
+  __atomic_bool_bysize (__arch_c_compare_and_exchange_bool,acq,		      \
+		        mem, newval, oldval)
+#  else
+#   define catomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
+  ({ /* Cannot use __oldval here, because macros later in this file might     \
+	call this macro with __oldval argument.	 */			      \
+     __typeof (oldval) __atg4_old = (oldval);				      \
+     catomic_compare_and_exchange_val_acq (mem, newval, __atg4_old)	      \
+       != __atg4_old;							      \
   })
 # endif
 #endif
@@ -100,21 +160,26 @@
 #endif
 
 
+#ifndef catomic_compare_and_exchange_bool_rel
+# define catomic_compare_and_exchange_bool_rel(mem, newval, oldval) \
+  catomic_compare_and_exchange_bool_acq (mem, newval, oldval)
+#endif
+
+
 /* Store NEWVALUE in *MEM and return the old value.  */
 #ifndef atomic_exchange_acq
 # define atomic_exchange_acq(mem, newvalue) \
-  ({ __typeof (*(mem)) __oldval;					      \
-     __typeof (mem) __memp = (mem);					      \
-     __typeof (*(mem)) __value = (newvalue);				      \
+  ({ __typeof (*(mem)) __atg5_oldval;					      \
+     __typeof (mem) __atg5_memp = (mem);				      \
+     __typeof (*(mem)) __atg5_value = (newvalue);			      \
 									      \
      do									      \
-       __oldval = *__memp;						      \
-     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
-								    __value,  \
-								    __oldval),\
-			      0));					      \
+       __atg5_oldval = *__atg5_memp;					      \
+     while (__builtin_expect						      \
+	    (atomic_compare_and_exchange_bool_acq (__atg5_memp, __atg5_value, \
+						   __atg5_oldval), 0));	      \
 									      \
-     __oldval; })
+     __atg5_oldval; })
 #endif
 
 #ifndef atomic_exchange_rel
@@ -125,72 +190,124 @@
 /* Add VALUE to *MEM and return the old value of *MEM.  */
 #ifndef atomic_exchange_and_add
 # define atomic_exchange_and_add(mem, value) \
-  ({ __typeof (*(mem)) __oldval;					      \
-     __typeof (mem) __memp = (mem);					      \
-     __typeof (*(mem)) __value = (value);				      \
+  ({ __typeof (*(mem)) __atg6_oldval;					      \
+     __typeof (mem) __atg6_memp = (mem);				      \
+     __typeof (*(mem)) __atg6_value = (value);				      \
 									      \
      do									      \
-       __oldval = *__memp;						      \
-     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
-								    __oldval  \
-								    + __value,\
-								    __oldval),\
-			      0));					      \
+       __atg6_oldval = *__atg6_memp;					      \
+     while (__builtin_expect						      \
+	    (atomic_compare_and_exchange_bool_acq (__atg6_memp,		      \
+						   __atg6_oldval	      \
+						   + __atg6_value,	      \
+						   __atg6_oldval), 0));	      \
 									      \
-     __oldval; })
+     __atg6_oldval; })
 #endif
 
 
+#ifndef catomic_exchange_and_add
+# define catomic_exchange_and_add(mem, value) \
+  ({ __typeof (*(mem)) __atg7_oldv;					      \
+     __typeof (mem) __atg7_memp = (mem);				      \
+     __typeof (*(mem)) __atg7_value = (value);				      \
+									      \
+     do									      \
+       __atg7_oldv = *__atg7_memp;					      \
+     while (__builtin_expect						      \
+	    (catomic_compare_and_exchange_bool_acq (__atg7_memp,	      \
+						    __atg7_oldv		      \
+						    + __atg7_value,	      \
+						    __atg7_oldv), 0));	      \
+									      \
+     __atg7_oldv; })
+#endif
+
 
 #ifndef atomic_max
 # define atomic_max(mem, value) \
   do {									      \
-    __typeof (*(mem)) __oldval;						      \
-    __typeof (mem) __memp = (mem);					      \
-    __typeof (*(mem)) __value = (value);				      \
+    __typeof (*(mem)) __atg8_oldval;					      \
+    __typeof (mem) __atg8_memp = (mem);					      \
+    __typeof (*(mem)) __atg8_value = (value);				      \
+    do {								      \
+      __atg8_oldval = *__atg8_memp;					      \
+      if (__atg8_oldval >= __atg8_value)				      \
+	break;								      \
+    } while (__builtin_expect						      \
+	     (atomic_compare_and_exchange_bool_acq (__atg8_memp, __atg8_value,\
+						    __atg8_oldval), 0));      \
+  } while (0)
+#endif
+
+
+#ifndef catomic_max
+# define catomic_max(mem, value) \
+  do {									      \
+    __typeof (*(mem)) __atg9_oldv;					      \
+    __typeof (mem) __atg9_memp = (mem);					      \
+    __typeof (*(mem)) __atg9_value = (value);				      \
     do {								      \
-      __oldval = *__memp;						      \
-      if (__oldval >= __value)						      \
+      __atg9_oldv = *__atg9_memp;					      \
+      if (__atg9_oldv >= __atg9_value)					      \
 	break;								      \
-    } while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,  \
-								     __value, \
-								     __oldval),\
-			       0));					      \
+    } while (__builtin_expect						      \
+	     (catomic_compare_and_exchange_bool_acq (__atg9_memp,	      \
+						     __atg9_value,	      \
+						     __atg9_oldv), 0));	      \
   } while (0)
 #endif
 
+
 #ifndef atomic_min
 # define atomic_min(mem, value) \
   do {									      \
-    __typeof (*(mem)) __oldval;						      \
-    __typeof (mem) __memp = (mem);					      \
-    __typeof (*(mem)) __value = (value);				      \
+    __typeof (*(mem)) __atg10_oldval;					      \
+    __typeof (mem) __atg10_memp = (mem);				      \
+    __typeof (*(mem)) __atg10_value = (value);				      \
     do {								      \
-      __oldval = *__memp;						      \
-      if (__oldval <= __value)						      \
+      __atg10_oldval = *__atg10_memp;					      \
+      if (__atg10_oldval <= __atg10_value)				      \
 	break;								      \
-    } while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,  \
-								     __value, \
-								     __oldval),\
-			       0));					      \
+    } while (__builtin_expect						      \
+	     (atomic_compare_and_exchange_bool_acq (__atg10_memp,	      \
+						    __atg10_value,	      \
+						    __atg10_oldval), 0));     \
   } while (0)
 #endif
 
+
 #ifndef atomic_add
 # define atomic_add(mem, value) (void) atomic_exchange_and_add ((mem), (value))
 #endif
 
 
+#ifndef catomic_add
+# define catomic_add(mem, value) \
+  (void) catomic_exchange_and_add ((mem), (value))
+#endif
+
+
 #ifndef atomic_increment
 # define atomic_increment(mem) atomic_add ((mem), 1)
 #endif
 
 
+#ifndef catomic_increment
+# define catomic_increment(mem) catomic_add ((mem), 1)
+#endif
+
+
 #ifndef atomic_increment_val
 # define atomic_increment_val(mem) (atomic_exchange_and_add ((mem), 1) + 1)
 #endif
 
 
+#ifndef catomic_increment_val
+# define catomic_increment_val(mem) (catomic_exchange_and_add ((mem), 1) + 1)
+#endif
+
+
 /* Add one to *MEM and return true iff it's now zero.  */
 #ifndef atomic_increment_and_test
 # define atomic_increment_and_test(mem) \
@@ -203,11 +320,21 @@
 #endif
 
 
+#ifndef catomic_decrement
+# define catomic_decrement(mem) catomic_add ((mem), -1)
+#endif
+
+
 #ifndef atomic_decrement_val
 # define atomic_decrement_val(mem) (atomic_exchange_and_add ((mem), -1) - 1)
 #endif
 
 
+#ifndef catomic_decrement_val
+# define catomic_decrement_val(mem) (catomic_exchange_and_add ((mem), -1) - 1)
+#endif
+
+
 /* Subtract 1 from *MEM and return true iff it's now zero.  */
 #ifndef atomic_decrement_and_test
 # define atomic_decrement_and_test(mem) \
@@ -218,35 +345,34 @@
 /* Decrement *MEM if it is > 0, and return the old value.  */
 #ifndef atomic_decrement_if_positive
 # define atomic_decrement_if_positive(mem) \
-  ({ __typeof (*(mem)) __oldval;					      \
-     __typeof (mem) __memp = (mem);					      \
+  ({ __typeof (*(mem)) __atg11_oldval;					      \
+     __typeof (mem) __atg11_memp = (mem);				      \
 									      \
      do									      \
        {								      \
-	 __oldval = *__memp;						      \
-	 if (__builtin_expect (__oldval <= 0, 0))			      \
+	 __atg11_oldval = *__atg11_memp;				      \
+	 if (__builtin_expect (__atg11_oldval <= 0, 0))			      \
 	   break;							      \
        }								      \
-     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
-								    __oldval  \
-								    - 1,      \
-								    __oldval),\
-			      0));\
-     __oldval; })
+     while (__builtin_expect						      \
+	    (atomic_compare_and_exchange_bool_acq (__atg11_memp,	      \
+						   __atg11_oldval - 1,	      \
+						   __atg11_oldval), 0));      \
+     __atg11_oldval; })
 #endif
 
 
 #ifndef atomic_add_negative
 # define atomic_add_negative(mem, value)				      \
-  ({ __typeof (value) __aan_value = (value);				      \
-     atomic_exchange_and_add (mem, __aan_value) < -__aan_value; })
+  ({ __typeof (value) __atg12_value = (value);				      \
+     atomic_exchange_and_add (mem, __atg12_value) < -__atg12_value; })
 #endif
 
 
 #ifndef atomic_add_zero
 # define atomic_add_zero(mem, value)					      \
-  ({ __typeof (value) __aaz_value = (value);				      \
-     atomic_exchange_and_add (mem, __aaz_value) == -__aaz_value; })
+  ({ __typeof (value) __atg13_value = (value);				      \
+     atomic_exchange_and_add (mem, __atg13_value) == -__atg13_value; })
 #endif
 
 
@@ -258,55 +384,102 @@
 
 #ifndef atomic_bit_test_set
 # define atomic_bit_test_set(mem, bit) \
-  ({ __typeof (*(mem)) __oldval;					      \
-     __typeof (mem) __memp = (mem);					      \
-     __typeof (*(mem)) __mask = ((__typeof (*(mem))) 1 << (bit));	      \
+  ({ __typeof (*(mem)) __atg14_old;					      \
+     __typeof (mem) __atg14_memp = (mem);				      \
+     __typeof (*(mem)) __atg14_mask = ((__typeof (*(mem))) 1 << (bit));	      \
 									      \
      do									      \
-       __oldval = (*__memp);						      \
-     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
-								    __oldval  \
-								    | __mask, \
-								    __oldval),\
-			      0));					      \
+       __atg14_old = (*__atg14_memp);					      \
+     while (__builtin_expect						      \
+	    (atomic_compare_and_exchange_bool_acq (__atg14_memp,	      \
+						   __atg14_old | __atg14_mask,\
+						   __atg14_old), 0));	      \
 									      \
-     __oldval & __mask; })
+     __atg14_old & __atg14_mask; })
 #endif
 
-/* Atomically *mem &= mask and return the old value of *mem.  */
+/* Atomically *mem &= mask.  */
 #ifndef atomic_and
 # define atomic_and(mem, mask) \
-  ({ __typeof (*(mem)) __oldval;					      \
-     __typeof (mem) __memp = (mem);					      \
-     __typeof (*(mem)) __mask = (mask);					      \
+  do {									      \
+    __typeof (*(mem)) __atg15_old;					      \
+    __typeof (mem) __atg15_memp = (mem);				      \
+    __typeof (*(mem)) __atg15_mask = (mask);				      \
+									      \
+    do									      \
+      __atg15_old = (*__atg15_memp);					      \
+    while (__builtin_expect						      \
+	   (atomic_compare_and_exchange_bool_acq (__atg15_memp,		      \
+						  __atg15_old & __atg15_mask, \
+						  __atg15_old), 0));	      \
+  } while (0)
+#endif
+
+/* Atomically *mem &= mask and return the old value of *mem.  */
+#ifndef atomic_and_val
+# define atomic_and_val(mem, mask) \
+  ({ __typeof (*(mem)) __atg16_old;					      \
+     __typeof (mem) __atg16_memp = (mem);				      \
+     __typeof (*(mem)) __atg16_mask = (mask);				      \
 									      \
      do									      \
-       __oldval = (*__memp);						      \
-     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
-								    __oldval  \
-								    & __mask, \
-								    __oldval),\
-			      0));					      \
+       __atg16_old = (*__atg16_memp);					      \
+     while (__builtin_expect						      \
+	    (atomic_compare_and_exchange_bool_acq (__atg16_memp,	      \
+						   __atg16_old & __atg16_mask,\
+						   __atg16_old), 0));	      \
 									      \
-     __oldval; })
+     __atg16_old; })
 #endif
 
 /* Atomically *mem |= mask and return the old value of *mem.  */
 #ifndef atomic_or
 # define atomic_or(mem, mask) \
-  ({ __typeof (*(mem)) __oldval;					      \
-     __typeof (mem) __memp = (mem);					      \
-     __typeof (*(mem)) __mask = (mask);					      \
+  do {									      \
+    __typeof (*(mem)) __atg17_old;					      \
+    __typeof (mem) __atg17_memp = (mem);				      \
+    __typeof (*(mem)) __atg17_mask = (mask);				      \
+									      \
+    do									      \
+      __atg17_old = (*__atg17_memp);					      \
+    while (__builtin_expect						      \
+	   (atomic_compare_and_exchange_bool_acq (__atg17_memp,		      \
+						  __atg17_old | __atg17_mask, \
+						  __atg17_old), 0));	      \
+  } while (0)
+#endif
+
+#ifndef catomic_or
+# define catomic_or(mem, mask) \
+  do {									      \
+    __typeof (*(mem)) __atg18_old;					      \
+    __typeof (mem) __atg18_memp = (mem);				      \
+    __typeof (*(mem)) __atg18_mask = (mask);				      \
+									      \
+    do									      \
+      __atg18_old = (*__atg18_memp);					      \
+    while (__builtin_expect						      \
+	   (catomic_compare_and_exchange_bool_acq (__atg18_memp,	      \
+						   __atg18_old | __atg18_mask,\
+						   __atg18_old), 0));	      \
+  } while (0)
+#endif
+
+/* Atomically *mem |= mask and return the old value of *mem.  */
+#ifndef atomic_or_val
+# define atomic_or_val(mem, mask) \
+  ({ __typeof (*(mem)) __atg19_old;					      \
+     __typeof (mem) __atg19_memp = (mem);				      \
+     __typeof (*(mem)) __atg19_mask = (mask);				      \
 									      \
      do									      \
-       __oldval = (*__memp);						      \
-     while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp,   \
-								    __oldval  \
-								    | __mask, \
-								    __oldval),\
-			      0));					      \
+       __atg19_old = (*__atg19_memp);					      \
+     while (__builtin_expect						      \
+	    (atomic_compare_and_exchange_bool_acq (__atg19_memp,	      \
+						   __atg19_old | __atg19_mask,\
+						   __atg19_old), 0));	      \
 									      \
-     __oldval; })
+     __atg19_old; })
 #endif
 
 #ifndef atomic_full_barrier