55 lines
No EOL
1.6 KiB
Text
55 lines
No EOL
1.6 KiB
Text
N = 2
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S = 3
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CLIENTS = {0..N-1}
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STATES = {0..S-1}
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channel input, render, up, down, save, saved, bufsave, bufsaved:CLIENTS.STATES
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apply(state, patch) = (state + patch) % S
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diff(state1, state2) = (state2 - state1) % S
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empty(patch) = patch == 0
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CLIENT(i, state, shadow) =
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input!i?new_state
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-> up!i!diff(shadow, new_state)
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-> CLIENT'(i, state, shadow)
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[] CLIENT'(i, state, shadow)
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CLIENT'(i, state, shadow) = down!i?patch
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-> if empty(patch)
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then CLIENT(i, state, state)
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else
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if diff(apply(shadow, patch), apply(state, patch)) != 0
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then
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render!i!apply(state, patch)
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-> up!i!diff(apply(shadow, patch), apply(state, patch))
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-> CLIENT(i, apply(state, patch), apply(shadow, patch))
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else
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render!i!apply(state, patch)
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-> CLIENT(i, apply(state, patch), apply(shadow, patch))
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SERVER(i, shadow) =
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up!i?patch
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-> save!i!patch
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-> bufsaved!i?new_state
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-> down!i!diff(apply(shadow, patch), new_state)
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-> SERVER(i, apply(shadow, patch))
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[] bufsaved?j?new_state
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-> if (new_state == shadow)
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then SERVER(i, shadow)
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else down!i!diff(shadow, new_state) -> SERVER(i, new_state)
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BUF(i) = saved?j?new_state -> BUF'(i, j, new_state)
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BUF'(i, j, new_state) = saved?j'?new_state' -> BUF'(i, j', new_state')
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[] bufsaved!j!new_state -> BUF(i)
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DB(state) = save?i?patch
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-> saved!i!apply(state, patch)
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-> DB(apply(state, patch))
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DBB = DB(0)
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CONN(i, init) = (CLIENT(i, init, init) [|{| up.i, down.i |}|] SERVER(i, init)) [|{| bufsaved |}|] BUF(i)
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SYSTEM = (CONN(0,0) [|{| save.0, saved |}|] DB(0)) [|{| save.1, saved |}|] CONN(1,0)
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assert SYSTEM :[deadlock free [F]] |