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Diffstat (limited to 'tools/memory-model/litmus-tests/MP+polocks.litmus')
| -rw-r--r-- | tools/memory-model/litmus-tests/MP+polocks.litmus | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/tools/memory-model/litmus-tests/MP+polocks.litmus b/tools/memory-model/litmus-tests/MP+polocks.litmus new file mode 100644 index 000000000..e6af05f70 --- /dev/null +++ b/tools/memory-model/litmus-tests/MP+polocks.litmus @@ -0,0 +1,35 @@ +C MP+polocks + +(* + * Result: Never + * + * This litmus test demonstrates how lock acquisitions and releases can + * stand in for smp_load_acquire() and smp_store_release(), respectively. + * In other words, when holding a given lock (or indeed after releasing a + * given lock), a CPU is not only guaranteed to see the accesses that other + * CPUs made while previously holding that lock, it is also guaranteed + * to see all prior accesses by those other CPUs. + *) + +{} + +P0(int *buf, int *flag, spinlock_t *mylock) // Producer +{ + WRITE_ONCE(*buf, 1); + spin_lock(mylock); + WRITE_ONCE(*flag, 1); + spin_unlock(mylock); +} + +P1(int *buf, int *flag, spinlock_t *mylock) // Consumer +{ + int r0; + int r1; + + spin_lock(mylock); + r0 = READ_ONCE(*flag); + spin_unlock(mylock); + r1 = READ_ONCE(*buf); +} + +exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *) |