What are the deadlock prevention methodologies?

a.       Necessitate that processes request all resources before starting - if cannot be granted don't run.

b.      Processes only allowed requesting resources when they hold none.

c.    If a resource request can't be granted to halt process and take away resources held. Give back and restart while all available simultaneously.

d.      If a resource request can't be granted to take them away from some other process.

e.     Offering a total ordering of resources and only grant requests if up along the order or release ones ahead in the order