formal models for component connectors David Filipe de Oliveira Costa formal models for component connectors Copyright © 2010 by David Costa Printed and bound by GVO printers & designers B.V. ISBN: 978-90-6464-436-8 IPA Dissertation Series 2010-10 The work reported in this thesis has been carried out at the Centrum Wiskunde & Informatica (CWI), under the auspices of the research school IPA (Institute for Pro- gramming research and Algorithmics). The research was funded by an FCT (The Portuguese Foundation for Science and Technology) grant (SFRH/BD/13762) and by the CWI group Foundations of Software Engineering (SEN3). Dedicated to the loving memory of my grandmothers Dedicado à memória das minhas duas queridas avós VRIJEUNIVERSITEIT formal models for component connectors ACADEMISCHPROEFSCHRIFT ter verkrijging van de graad Doctor aan de Vrije Universiteit Amsterdam, op gezag van de rector magnificus prof.dr. L.M. Bouter, in het openbaar te verdedigen ten overstaan van de promotiecommissie van de faculteit der Exacte Wetenschappen op maandag 13 december 2010 om 11.45 uur in de aula van de universiteit, De Boelelaan 1105 door David Filipe de Oliveira Costa geboren te Compiègne, Frankrijk promotoren: prof.dr. J.J.M.M. Rutten prof.dr. F. Arbab copromotoren: dr. M. Niqui dr. D.G. Clarke ACKNOWLEDGMENTS The writing of this thesis represents a lifetime landmark and thus far the most exciting journey of my life. Were it not for the help of many, I would have never been able to survive it, much less, conclude it. Trying to express in words how grateful and in debt I am to some of the people that made it possible is a difficult task, yet one that I am most definitely happy to do. I am hopelessly in debt to my promotors Jan Rutten and Farhad Arbab. I could not have hoped for better mentors. I only met Jan and Farhad personally when I moved to Amsterdam to start my PhD, and it did not take long for me to realise how fortunate I was to have them both as supervisors. Jan and Farhad have distinct scientific areas of expertise but share common interests. The topic of my thesis is one of their common interests, and the research reported in my thesis stems from their joint work on formal models (semantics) for connectors. I am immensely grateful for all I have learned from them. From Jan, for instance, I learned the importance of universal mathematical concepts and constructions, and how mathematics can be used to capture with elegance and simplicity concrete tangible problems. From Farhad, for example, I learned how important it is to present ones ideas with clarity and coherence. Any signs of simplicity or clarity in my thesis are entirely due to their influence. Jan and Farhad were not just my supervisors, they were also my closest friends, whenever I needed. During the long period I was writing up my thesis, Jan had the patience to meet regularly to discuss my drafts. His support and encouragement were unconditional and without parallel. Farhad had an incredible patiente to listen to my ideas and encouraged me to pursue them. Never complained about how inarticulate I was at times. He believed in me and made sure I knew it. Both taught me a great deal about life in general and most of what I know about research. The advises I received from them will stay with me for the rest of my life. I want to thank my daily supervisors and co-promotors Dave Clarke and Milad Niqui, who complemented the supervision by Jan and Farhad. Dave joined CWI and started his post-doc shortly after I started my PhD. We worked together on the semantics of Reo. The work we did together was very exciting, and eventually led to the results reported on Chapter 3. Dave has tremendous stamina and is very passionate about what he does. He strives for the best and he is very critical of his work. In our long and frequent discussions, I learned to question my ideas and compare them with the work of others. Shortly after Dave moved to Leuven where he had just been offered a professorship position, Milad joined our group at CWI and took on the role of my daily supervisor. At the time I was struggling to conclude the work on intentional automata and write up Chapters 4 and 5. In our ix regular meetings, Milad’s sharp mind never ceased to amaze me. After a couple of meetings I had overcome the problems I was facing and had found an effective routine that allowed me to produce regular drafts. I just hope we can continue collaborating. I would like to thank the members of my committee—Christel Baier, Marcello Bonsangue, Marco Aiello, Wan Fokkink, and Erik de Vink—for taking the time to read my manuscript and providing me with comments and remarks that helped me improve the final version of the thesis. A special thank goes to my former officemates, Freek Burger, Kees Everaars, Juan G. Scholten and José Proença. Freek and Kees took upon themselves to make me feel at home when I first arrived at CWI. On my very first day Kees took me to the bike shop, and that day I left the office riding on the fietspad of Amsterdam. Freek convinced me to join the group of ice skaters at CWI, and that is how I learned to schaatsen. I have fond memories of the summer Kees lent his house to me and my parents when they first came to visit me. Juan became a close and dear friend, always ready to listen and help. I recall with nostalgia our regular discussions about the most diverse topics while eating a pizza and having a beer at Pescara. José deserves a special thank you. José has been my companion and buddy through most of my PhD. We have been through a lot together. I recall specially the road trip we went on to switzerland to watch Portugal-against-Czech-Republic match, for the European Championship in 2008. The work on the connector animation reported in Chapter 6 has been our project and one I really enjoyed doing. I cannot thank Jose without saying thank you to Alexandra Silva. The three of us met at the University of Minho and have been close friends ever since. I did everything I could to persuade Zé and Xana to do their PhD at CWI and join me. I am so glad they did. I cannot imagine how my life in Amsterdam would have been without them. They make Portugal feel closer and are there whenever I need them. CWI is an amazing place. It offers to its employees the best conditions. I wish to thank all my friends and colleagues from CWI and especially the Foundations of Software Engineering (SEN3) group for the always pleasant atmosphere, all the great events, and discussions. Susanne van Dam deserves a special thank you, for being a friend always ready to help. She is the pendulum that guarantees the perfect functioning of our group. I have been lucky to make new friends in Amsterdam since the day I arrived. They are part of what has made and makes my everyday life in the Netherlands great and I thank you all for that—Adam, Ana Sokolova, Arjen, Behnaz, Christian, Clem- ens, Daniel and Stephanie, Dorina, Elmer and Edith, Elena, Fernando, Florence and Sibren, Frank, Filippo, Georgina and Wolker, Helle and Hartmutz, Ichiro and Ku- miko, Immo, Joost and Dina, Katharina, Kees Bloom, Lacramioara, Markéta, Mar- cello, Marcin, Marjan, Mohammad Dashti, MohammadMahdi Jaghouri, Moham- madReza Mousavi, Michiel, Myoung Jin Nam, Natalia, Nikolay, Peter and Wendy, x Peter Zoeteweij, Rodrigo, Ronny and Rocio, Stephanie, Stijn Keijzer, Stijn Oonk, Sun, Thijs, Tom, Young Joo. Living in Amsterdam means that I have to be far away from my family and my friends in Portugal. It hurts to be apart: As saudades são sempre muitas. They make me a better person, and I owe everything I have accomplished to them. I thank with all my heart my entire familly, and in particular a minha mãe Dina, o meu pai Ricardo, o meu mano caçula Bruno and his girlfriend Ana for just everything. My family extends to my hometown and forever friends: o meu outro irmão João Paulo, os meus primos Vitor and Ricardo, o meu parceiro de carteira Ricardo, os meus parceiros de sueca Rui and Vasco, and o meu amigo do secundário Zé. Every time we are together they make me feel like I never left. Thank you! Many thanks to my friends, including the 5F family—Ângelo e Ticha, Miguel e Susana, Jorge, António Pedro, Maria João, Catarina, Dino, Manel, Rui e Joana, Rui e Conceição, Patrícia, Artur, Márcio e Cristina, Ana Luísa, Alexandre, Inês e Gonçalo, Ana Rita, Madaleno, Pi, Ângela, Cândida, Susana Carvalho, Gonçalo Pacheco, Neusa—for being such an amazing and special group of friends. The 5F activities have by now become traditions and are the highlights of most of my trips to Portugal. My dear friends Maria João and Catarina deserve a dedicated thank you. With their visits to Amsterdam and our summer vacation in Italy, they made sure I kept my sanity throughout my PhD. I wish to thank my professors at the Departamento of Informatica, who have inspired me throughout my studies: José Bernardo Barros, José Nuno Oliveira, Manuel Barbosa, Jorge Sousa Pinto, Alberto Proença, José Valença, Luís Pinto, and last but not least Luís Barbosa who took me under his wing and made it possible for me to apply for a position at CWI and obtain a PhD grant.