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This document outlines the implementation details of a causal message delivery protocol, using existing modules and synchronizing vector clocks (VC) across multiple processes. It describes the handling of message inputs and outputs, the management of virtual clocks, and the necessary conditions for timestamp updates during messaging events. Key functionalities include serialization of vector clocks, message queuing, input validation, and conditional message display based on system states. This ensures reliable communication and temporal consistency among distributed processes.
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Bud Causal Delivery Implémentation
L’existant… moduleDeliveryProtocol state do interface input, :pipe_in,[:dst, :src, :ident]=>[:payload] interface output, :pipe_sent,[:dst, :src, :ident]=>[:payload] interface output, :pipe_out,[:dst, :src, :ident]=>[:payload] end end moduleCausalDelivery includeDeliveryProtocol state do channel :chn,[:@dst, :src, :ident]=>[:payload, :clock, :ord_buf] lmap :my_vc lmap :next_vc lmap :ord_buf table :recv_buf,chn.schema scratch :buf_chosen,recv_buf.schema end bootstrapdo my_vc<={ip_port=>Bud::MaxLattice.new(0)} end
L’existant… bloom :update_vcdo next_vc<=my_vc next_vc<=pipe_in{{ip_port=> my_vc.at(ip_port)+1}} next_vc<=buf_chosen{{ip_port=> my_vc.at(ip_port)+1}} next_vc<=buf_chosen{|m|m.clock} my_vc<+next_vc end bloom :outbound_msgdo chn<~pipe_in{|p|[p.dst, p.src,p.ident,p.payload,next_vc,ord_buf]} ord_buf<+pipe_in{|p|{p.dst =>next_vc}} pipe_sent<=pipe_in end bloom :inbound_msgdo recv_buf<=chn buf_chosen<=recv_buf{|m| m.ord_buf.at(ip_port,Bud::MapLattice).lt_eq(my_vc).when_true{ m }} recv_buf<-buf_chosen pipe_out<=buf_chosen{|m|[m.dst, m.src,m.ident,m.payload]} ord_buf<+buf_chosen{|m| m.ord_buf} end end
Modifications à effectuer • Fonction de hachage • [n° processus] => [ entrées dans le VC] • Incrémentation des horloges à la réception • Sous condition • Incrémentation des horloges à l’envoi • Inconditionnel • Affichage des messages • Doublement conditionné
Utilitaires • Pour sérialiser des BudTable moduleVCTableSerializeModule defto_a @v end defto_s @v.inspect end end classVCTableSerialize includeVCTableSerializeModule definitialize(vc) raise "VCTableSerialize.initialize : first parameter must be a Bud::BudTable" if notvc.is_a?(Bud::BudTable) tmp= vc.map do|item| [ item[0], item[1]] end tmp.sort! {|x, y| x[0]<=> y[0]} @v = tmp.map do|item| item[1] end end end
Utilitaires • Pour réaliser des tests sur les VC moduleVCTestModule attr_reader :v deffirst_test(vc, entries) raise "VCTestModule.first_test : first parameter must be a VCTest" if notvc.is_a?(VCTest) raise "VCTestModule.first_test : second parameter must be an Array" if notentries.is_a?(Array) isSuccess=true for e in entries isSuccess=isSuccessand(@v[e]-1<=vc.v[e]) end returnisSuccess end defsecond_test(vc,forbidEntries) raise "VCTestModule.second_test : first parameter must be a VCTest" if notvc.is_a?(VCTest) raise "VCTestModule.second_test : second parameter must be an Array" if notforbidEntries.is_a?(Array) j=0 result=[] for i in(0..vc.v.length-1) ifforbidEntries.index(i)==nil result[j]= i j = j+1 end end isSuccess=true for e inresult isSuccess=isSuccessand(@v[e]<=vc.v[e]) end returnisSuccess end
Utilitaires defthird_test(vc, entries) raise "VCTestModule.third_test : first parameter must be a VCTest" if notvc.is_a?(VCTest) raise "VCTestModule.third_test : second parameter must be an Array" if notentries.is_a?(Array) isSuccess=true for e in entries isSuccess=isSuccessand(@v[e]-1==vc.v[e]) end returnisSuccess end End classVCTest includeVCTestModule definitialize(vc) raise "VCTest.initialize : first parameter must be an Array" if notvc.is_a?(Array) @v =vc end end
Fonction de hachage • Simulée par une Map • Fixée pour 5 processus @fi ={1=>[0,2], 2=>[1,3], 3=>[2,4], 4=>[0,3], 5=>[1,4]}
Incrémentation des horloges - Réception • Définition de deux nouveaux scratch scratch :chn_tmp,chn.schema scratch :next_vc_tmp,next_vc.schema • Quand un message arrive, on se prépare à l’afficher, même si les conditions d’affichage ne sont pas validées • Incrémentation d’horloges provisoires • Si le message est réellement affiché, application des modifications à l’horloge du processus
Incrémentation des horloges - Réception chn_tmp<=chn{|c|Bud::BoolLattice.new(VCTest.new(c.clock).third_test(VCTest.new( VCTableSerialize.new(my_vc).to_a@fi[c.src])).when_true{ c }} next_vc_tmp<=chn_tmp.flat_mapdo|t| @fi[t.src].map {|e| [e,VCTableSerialize.new(my_vc).to_a[e]+1]} end next_vc<=pipe_out.flat_mapdo|p| next_vc_tmp.map {|i|[ i[0], i[1]]} end next_vc<=pipe_out.flat_mapdo|p| my_vc.map {|i| Bud::BoolLattice.new(@fi[p.src].index(i[0])==nil).when_true {[i[0],i[1]]}} end
Incrémentation des horloges - Envoi • Incrémentation dès qu’un message est en demande d’envoi next_vc<=pipe_in.flat_mapdo|p| my_vc.map {|i| Bud::BoolLattice.new(@fi[@src].index(i[0])!=nil) .when_true{[i[0],i[1]+1]}} end next_vc<=pipe_in.flat_mapdo|p| my_vc.map {|i| Bud::BoolLattice.new(@fi[@src].index(i[0])==nil) .when_true{[i[0],i[1]]}} end
Affichage des messages bloom :inbound_msgdo recv_buf<=chn buf_chosen_first<=recv_buf{|m|Bud::BoolLattice.new(VCTest.new(m.clock).first_test( VCTest.new(VCTableSerialize.new(my_vc).to_a),@fi[m.src])) .when_true{ m }} buf_chosen_second<=buf_chosen_first{|m|Bud::BoolLattice.new(VCTest.new(m.clock).second_test( VCTest.new(VCTableSerialize.new(my_vc).to_a), @fi[m.src]+ @fi[@src])) .when_true{ m }} recv_buf<-buf_chosen_second pipe_out<=buf_chosen_second{|m|[m.dst, m.src,m.content]} end
