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Diffstat (limited to 'tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus')
-rw-r--r-- | tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus b/tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus new file mode 100644 index 000000000..f8ca12298 --- /dev/null +++ b/tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus @@ -0,0 +1,30 @@ +C MP+fencewmbonceonce+fencermbonceonce + +(* + * Result: Never + * + * This litmus test demonstrates that smp_wmb() and smp_rmb() provide + * sufficient ordering for the message-passing pattern. However, it + * is usually better to use smp_store_release() and smp_load_acquire(). + *) + +{} + +P0(int *buf, int *flag) // Producer +{ + WRITE_ONCE(*buf, 1); + smp_wmb(); + WRITE_ONCE(*flag, 1); +} + +P1(int *buf, int *flag) // Consumer +{ + int r0; + int r1; + + r0 = READ_ONCE(*flag); + smp_rmb(); + r1 = READ_ONCE(*buf); +} + +exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *) |