Mutual exclusion(at most one client has access to resource)

-module(client).

start_link(Locker) ->

{ok,spawn_link(loop,[Locker])}.

loop(Locker) ->

gen_server:call(Locker,request),

critical(),

gen_server:call(Locker,release),

loop(Locker).

io:format(“enter cs~n”),

critical(),

io:format(“exit cs~n”),

erlang:trace

for gen_server:call

Mutual exclusion (at most one client has access to resource)