Incorporating input/output operations into dynamic data-flow graphs
Gaudiot, J. -L
Google Scholar check
MetadataShow full item record
Driven by the 'side-effect' environment of sequential von Neumann computing, Input/Output operations have evolved as state operations on shared files. In parallel programs, if multiple instances of an I/O-performing process execute concurrently, either the user or the system must synchronize any accesses to shared files. Data-flow principles of execution provide an elegant way to ensure at runtime that instructions can be executed asynchronously in a parallel environment. However, while the conventional von Neumann model of interpretation inherited a rigid ordering of instructions, it is the very asynchronous character of the data-flow model of execution which introduces conflicts when 'state' tasks (such as I/O operations) must share common data objects. The scheme presented in this paper, Logical Serialization with Distributed File Pointers (LS-DFP), introduces the two basic I/O operations read and write into the dynamic data-flow graph. However, sequencing I/O operations on the same file based on the availability of data as in 'conventional' data-flow is not possible because the name of the file becomes available simultaneously to all operations at program initiation. To impose an order, we sequentialize, (logically serialize-LS), the operations according to their lexicographical ordering. Furthermore, several optimizations are introduced that allow the distributed execution of these I/O operations with the use of Distributed File Pointers (DFP). Thus, the LS-DFP scheme can utilize the full level of parallelism of the dynamic data-flow principles of execution. © 1995.
Showing items related by title, author, creator and subject.
Nicolaou, Christos A.; Kannas, Christos C.; Pattichis, Constantinos S. (2009)Designing appropriate graphs is a problem frequently occurring in several common applications ranging from designing communication and transportation networks to discovering new drugs. More often than not the graphs to be ...
Hadjicostis, Christoforos N.; Domínguez-Garcia, A. D. (2018)We consider networks the nodes of which are interconnected via directed edges, each able to admit a flow (or weight) within a certain interval, with nonnegative end points that correspond to lower and upper flow limits. ...
Oliva, G.; Setola, R.; Glielmo, L.; Hadjicostis, Christoforos N. (2018)In this paper, we provide distributed algorithms to detect and remove cycles in a directed relational graph by exploiting the underlying undirected communication graph; the relational graph models a relation among the ...