b6ff30849c
This commit adds comments that label the MP tests' producer and consumer processes, and also that label the "exists" clause as the bad outcome. Reported-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
31 lines
408 B
Plaintext
31 lines
408 B
Plaintext
C MP+poonceonces
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(*
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* Result: Sometimes
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*
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* Can the counter-intuitive message-passing outcome be prevented with
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* no ordering at all?
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*)
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{
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int buf;
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int flag;
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}
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P0(int *buf, int *flag) // Producer
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{
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WRITE_ONCE(*buf, 1);
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WRITE_ONCE(*flag, 1);
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}
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P1(int *buf, int *flag) // Consumer
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{
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int r0;
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int r1;
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r0 = READ_ONCE(*flag);
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r1 = READ_ONCE(*buf);
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}
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exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *)
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