+2012-02-13 Richard Henderson <rth@redhat.com>
+
+ PR libstdc++/51798 continued.
+ * include/bits/shared_ptr_base.h
+ (_Sp_counted_base<_S_atomic>::_M_add_ref_lock): Hoist initial load
+ outside compare_exchange loop.
+ * include/tr1/shared_ptr.h: Same.
+ * include/parallel/compatibility.h (__compare_and_swap_32): Use strong
+ version of compare_exchange.
+ (__compare_and_swap_64): Same.
+ * include/profile/impl/profiler_state.h (__gnu_profile::__turn): Same.
+ * libsupc++/guard.cc (__cxa_guard_acquire): Same.
+
2012-02-10 Benjamin Kosnik <bkoz@redhat.com>
Jonathan Wakely <jwakely.gcc@gmail.com>
_M_add_ref_lock()
{
// Perform lock-free add-if-not-zero operation.
- _Atomic_word __count;
+ _Atomic_word __count = _M_use_count;
do
{
- __count = _M_use_count;
if (__count == 0)
__throw_bad_weak_ptr();
-
// Replace the current counter value with the old value + 1, as
// long as it's not changed meanwhile.
}
__replacement, __comparand)
== __comparand;
#elif defined(__GNUC__)
- return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, true,
- __ATOMIC_ACQ_REL, __ATOMIC_RELAXED);
+ return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement,
+ false, __ATOMIC_ACQ_REL,
+ __ATOMIC_RELAXED);
#elif defined(__SUNPRO_CC) && defined(__sparc)
return atomic_cas_32((volatile unsigned int*)__ptr, __comparand,
__replacement) == __comparand;
#endif
#elif defined(__GNUC__) && defined(__x86_64)
- return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, true,
- __ATOMIC_ACQ_REL, __ATOMIC_RELAXED);
+ return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement,
+ false, __ATOMIC_ACQ_REL,
+ __ATOMIC_RELAXED);
#elif defined(__GNUC__) && defined(__i386) && \
(defined(__i686) || defined(__pentium4) || defined(__athlon) \
|| defined(__k8) || defined(__core2))
- return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement, true,
- __ATOMIC_ACQ_REL, __ATOMIC_RELAXED);
+ return __atomic_compare_exchange_n(__ptr, &__comparand, __replacement,
+ false, __ATOMIC_ACQ_REL,
+ __ATOMIC_RELAXED);
#elif defined(__SUNPRO_CC) && defined(__sparc)
return atomic_cas_64((volatile unsigned long long*)__ptr,
__comparand, __replacement) == __comparand;
{
__state_type inv(__INVALID);
return __atomic_compare_exchange_n(&_GLIBCXX_PROFILE_DATA(__state),
- &inv, __s, true, __ATOMIC_ACQ_REL,
+ &inv, __s, false, __ATOMIC_ACQ_REL,
__ATOMIC_RELAXED);
}
_M_add_ref_lock()
{
// Perform lock-free add-if-not-zero operation.
- _Atomic_word __count;
+ _Atomic_word __count = _M_use_count;
do
{
- __count = _M_use_count;
if (__count == 0)
__throw_bad_weak_ptr();
-
// Replace the current counter value with the old value + 1, as
// long as it's not changed meanwhile.
}
while (1)
{
- if (__atomic_compare_exchange_n(gi, &expected, pending_bit, true,
- __ATOMIC_ACQ_REL, __ATOMIC_RELAXED))
+ if (__atomic_compare_exchange_n(gi, &expected, pending_bit, false,
+ __ATOMIC_ACQ_REL,
+ __ATOMIC_RELAXED))
{
// This thread should do the initialization.
return 1;
if (expected == pending_bit)
{
int newv = expected | waiting_bit;
- if (!__atomic_compare_exchange_n(gi, &expected, newv, true,
+ if (!__atomic_compare_exchange_n(gi, &expected, newv, false,
__ATOMIC_ACQ_REL,
__ATOMIC_RELAXED))
continue;