* ruby_atomic.h (ATOMIC_CAS): added.

* signal.c (ruby_atomic_compare_and_swap): ATOMIC_CAS implementation
  for non-VC/gcc platform.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@44950 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 16 insertions, 0 deletions

diff --git a/ruby_atomic.h b/ruby_atomic.h
index 548adee347..1c64eadb91 100644
--- a/ruby_atomic.h
+++ b/ruby_atomic.h
@@ -13,6 +13,7 @@ typedef unsigned int rb_atomic_t; /* Anything OK */
 # define ATOMIC_DEC(var) __sync_fetch_and_sub(&(var), 1)
 # define ATOMIC_OR(var, val) __sync_or_and_fetch(&(var), (val))
 # define ATOMIC_EXCHANGE(var, val) __sync_lock_test_and_set(&(var), (val))
+# define ATOMIC_CAS(var, oldval, newval) __sync_val_compare_and_swap(&(var), (oldval), (newval))
 
 # define ATOMIC_SIZE_ADD(var, val) __sync_fetch_and_add(&(var), (val))
 # define ATOMIC_SIZE_SUB(var, val) __sync_fetch_and_sub(&(var), (val))
@@ -49,7 +50,17 @@ rb_w32_atomic_or(volatile rb_atomic_t *var, rb_atomic_t val)
 # define ATOMIC_OR(var, val) _InterlockedOr(&(var), (val))
 #endif
 # define ATOMIC_EXCHANGE(var, val) InterlockedExchange(&(var), (val))
+# define ATOMIC_CAS(var, oldval, newval) InterlockedCompareExchange(&(var), (newval), (oldval))
 
+# if defined _MSC_VER && _MSC_VER <= 1200
+static inline rb_atomic_t
+rb_w32_atomic_cas(volatile rb_atomic_t *var, rb_atomic_t oldval, rb_atomic_t newval)
+{
+    return (rb_atomic_t)InterlockedCompareExchange((PVOID *)var, (PVOID)newval, (PVOID)oldval);
+}
+#   undef ATOMIC_CAS
+#   define ATOMIC_CAS(var, oldval, newval) rb_w32_atomic_cas(&(var), (oldval), (newval))
+# endif
 # ifdef _M_AMD64
 #  define ATOMIC_SIZE_ADD(var, val) InterlockedExchangeAdd64(&(var), (val))
 #  define ATOMIC_SIZE_SUB(var, val) InterlockedExchangeAdd64(&(var), -(val))
@@ -74,6 +85,7 @@ typedef unsigned int rb_atomic_t;
 # define ATOMIC_DEC(var) atomic_dec_uint(&(var))
 # define ATOMIC_OR(var, val) atomic_or_uint(&(var), (val))
 # define ATOMIC_EXCHANGE(var, val) atomic_swap_uint(&(var), (val))
+# define ATOMIC_CAS(var, oldval, newval) atomic_cas_uint(&(var), (oldval), (newval))
 
 # if SIZEOF_SIZE_T == SIZEOF_LONG
 #  define ATOMIC_SIZE_ADD(var, val) atomic_add_long(&(var), (val))
@@ -93,12 +105,16 @@ typedef unsigned int rb_atomic_t;
 typedef int rb_atomic_t;
 #define NEED_RUBY_ATOMIC_EXCHANGE
 extern rb_atomic_t ruby_atomic_exchange(rb_atomic_t *ptr, rb_atomic_t val);
+extern rb_atomic_t ruby_atomic_compare_and_swap(rb_atomic_t *ptr,
+						rb_atomic_t cmp,
+						rb_atomic_t newval);
 
 # define ATOMIC_SET(var, val) (void)((var) = (val))
 # define ATOMIC_INC(var) ((var)++)
 # define ATOMIC_DEC(var) ((var)--)
 # define ATOMIC_OR(var, val) ((var) |= (val))
 # define ATOMIC_EXCHANGE(var, val) ruby_atomic_exchange(&(var), (val))
+# define ATOMIC_CAS(var, oldval, newval) ruby_atomic_compare_and_swap(&(var), (oldval), (newval))
 
 # define ATOMIC_SIZE_ADD(var, val) (void)((var) += (val))
 # define ATOMIC_SIZE_SUB(var, val) (void)((var) -= (val))