Mercurial > hg > graal-jvmci-8
diff src/os_cpu/bsd_zero/vm/atomic_bsd_zero.inline.hpp @ 22854:4ebc1b290dbd
8067331: Zero: Atomic::xchg and Atomic::xchg_ptr need full memory barrier
Reviewed-by: dholmes, coleenp
| author | sgehwolf |
|---|---|
| date | Tue, 24 Feb 2015 21:17:59 -0500 |
| parents | 63e54c37ac64 |
| children |
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--- a/src/os_cpu/bsd_zero/vm/atomic_bsd_zero.inline.hpp Mon Dec 15 09:36:46 2014 +0100 +++ b/src/os_cpu/bsd_zero/vm/atomic_bsd_zero.inline.hpp Tue Feb 24 21:17:59 2015 -0500 @@ -238,7 +238,13 @@ // operation. Note that some platforms only support this with the // limitation that the only valid value to store is the immediate // constant 1. There is a test for this in JNI_CreateJavaVM(). - return __sync_lock_test_and_set (dest, exchange_value); + jint result = __sync_lock_test_and_set (dest, exchange_value); + // All atomic operations are expected to be full memory barriers + // (see atomic.hpp). However, __sync_lock_test_and_set is not + // a full memory barrier, but an acquire barrier. Hence, this added + // barrier. + __sync_synchronize(); + return result; #endif // M68K #endif // ARM } @@ -251,7 +257,9 @@ #ifdef M68K return m68k_lock_test_and_set(dest, exchange_value); #else - return __sync_lock_test_and_set (dest, exchange_value); + intptr_t result = __sync_lock_test_and_set (dest, exchange_value); + __sync_synchronize(); + return result; #endif // M68K #endif // ARM }