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Diffstat (limited to 'tools/memory-model/litmus-tests/ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus')
-rw-r--r-- | tools/memory-model/litmus-tests/ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/tools/memory-model/litmus-tests/ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus b/tools/memory-model/litmus-tests/ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus new file mode 100644 index 000000000..025b0462e --- /dev/null +++ b/tools/memory-model/litmus-tests/ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus @@ -0,0 +1,39 @@ +C ISA2+pooncerelease+poacquirerelease+poacquireonce + +(* + * Result: Never + * + * This litmus test demonstrates that a release-acquire chain suffices + * to order P0()'s initial write against P2()'s final read. The reason + * that the release-acquire chain suffices is because in all but one + * case (P2() to P0()), each process reads from the preceding process's + * write. In memory-model-speak, there is only one non-reads-from + * (AKA non-rf) link, so release-acquire is all that is needed. + *) + +{} + +P0(int *x, int *y) +{ + WRITE_ONCE(*x, 1); + smp_store_release(y, 1); +} + +P1(int *y, int *z) +{ + int r0; + + r0 = smp_load_acquire(y); + smp_store_release(z, 1); +} + +P2(int *x, int *z) +{ + int r0; + int r1; + + r0 = smp_load_acquire(z); + r1 = READ_ONCE(*x); +} + +exists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0) |