digraph finite_state_machine {
    node [shape = circle, fixedsize=true, fontsize=12];
    edge [fontsize=9];
    I -> RSC [ label = "ReadShared" ];
    RU -> RSD [ label = "ReadShared/\nSnpShared, dirty resp" ];
    RU -> RSC [ label = "ReadShared/\nSnpShared, clean resp" ];
    I -> RU [ label = "ReadUnique" ];
    I,RSC,RSD -> RU [ label = "ReadUnique/\nSnpUnique" ];
    RSC -> I [ label = "Evict (#sharers>0)" ];
    RSD -> RSC [ label = "WriteBack (#sharers>0)" ];
    RSD -> I [ label = "WriteBack (#sharers=0)" ];
    RU -> I [ label = "WriteBack" ];
    RU -> I [ label = "WriteEvict" ];
    RU -> RSC [ label = "SnpShared/\nSnpShared, clean resp" ];
    RU -> RSD [ label = "SnpShared/\nSnpShared, dirty resp" ];
    RU,RSC,RSD -> I [ label = "SnpUnique" ];
}