Reconciling transactional conflicts with compiler's help

Software transactional memory(STM) is a promising programming paradigm for shared memory multithreaded programs. While STM offers the promise of being less error-prone and more programmer friendly compared to traditional lock-based synchronization, it also needs to be competitive in performance in order for it to be adopted in mainstream software. A major source of performance overheads in STM is transactional aborts. Conflict resolution and aborting a transaction typically happens at the transaction level which has the advantage that it is automatic and application agnostic. However it has a substantial disadvantage in that STM declares the entire transaction as conflicting and hence aborts it and re-executes it fully, instead of partially re-executing only those part(s) of the transaction, which have been affected due to the conflict. This "Re-execute Everything" approach has a significant adverse impact on STM performance. In order to mitigate the abort overheads, we propose a compiler aided Selective Reconciliation STM (SR-STM) scheme, wherein certain transactional conflicts can be reconciled by performing partial re-execution of the transaction. Ours is a selective hybrid approach which uses compiler analysis to identify those data accesses which are legal and profitable candidates for reconciliation and applies partial re-execution only to these candidates selectively while other conflicting data accesses are handled by the default STM approach of abort and full re-execution. We describe the compiler analysis and code transformations required for supporting selective reconciliation. We find that SR-STM is effective in reducing the transactional abort overheads by improving the performance for a set of five STAMP benchmarks by 12.58% on an average and up to 22.34%

The Author-Performer Divide in Intellectual Property Law: A Comparative Analysis of the American, Australian, British and French Legal Frameworks

Western intellectual property frameworks have at least one feature in common: performers are less protected than authors. This situation knows many justifications, although all but one have been dismissed by the literature: performers are simply less creative than authors. As a result, the legal protection covering their work has been proportionally reduced compared to that of their authorial peers. This thesis investigates this phenomenon that it calls the 'author-performer divide'. It uncovers the culturally-rooted principles and legal reasoning that policy-makers and judges of Australia, France, the United Kingdom and the United States have developed to create in the legal narrative a hierarchy between authors and performers. It reveals that those intellectual property systems, though continuously reformed, still contain outdated conceptions of creativity based on the belief in ex nihilo creation and over-intellectualised representations of the creative process. Those two precepts combined have led legal discourse to portray performers as their authors' puppets, thus underserving of authorship themselves. This thesis reviews arguments raised against improving the performers' regime to challenge the preconception of performers as uncreative agents and questions the divide it supports. To this end, it seeks to update the representations of creativity currently conveyed in the law by drawing on the findings of other academic disciplines such as creativity research, performance theories as well as music, theatre and dance studies. This comparative inter-disciplinary study aims to move current legal debates on performers' rights away from the recurring themes and repeated arguments in the scholarship such as issues of fixation or of competing claims, all of which have made conversations stagnate. By including disciplines beyond the law, this analysis seeks to advance the legal literature on the question of performers' intellectual property protection and shift thinking about performative forms of creativity