An overhead reducing technique for Time Warp

In this paper, we introduce a technique to reduce the number of state savings and the event queue size of Time Warp. By reducing the state saving and the sizes of event queues, we can decrease the overhead and the maximum memory requirement in Time Warp. We exploit the look-ahead technique to get a lower bound time stamp of the next event and to determine if an event is safe to be executed. No State saving is carried out when the event execution is safe. This lower bound can be used to discard saved states even though the time stamps are greater than the global virtual time (GVT). We prove that the proposed technique is correct under both aggressive and lazy cancellation schemes. This technique can be implemented with minimal additional overhead. Benchmark results on logic simulation show that the mechanism can reduce the number of state savings and memory size requirements significantly.

[1]  John A. Hamilton,et al.  Distributed Simulation , 1997 .

[2]  Darrin West,et al.  Automatic incremental state saving , 1996, Workshop on Parallel and Distributed Simulation.

[3]  Johan Montagnat,et al.  Transparent incremental state saving in time warp parallel discrete event simulation , 1996, Workshop on Parallel and Distributed Simulation.

[4]  Fabian Gomes,et al.  State saving for interactive optimistic simulation , 1997 .

[5]  Francesco Quaglia.  A Cost Model for Selecting Checkpoint Positions in Time Warp Parallel Simulation , 2001, IEEE Trans. Parallel Distributed Syst..

[6]  A. Weiss,et al.  Rollback sometimes works...if filtered , 1989, WSC '89.

[7]  George Varghese,et al.  The pessimism behind optimistic simulation , 1994, PADS '94.

[8]  Francesco Quaglia.  Event history based sparse state saving in time warp , 1998, Workshop on Parallel and Distributed Simulation.

[9]  John G. Cleary,et al.  An external state management system for optimistic parallel simulation , 1993, WSC '93.

[10]  Philip A. Wilsey,et al.  Comparative analysis of periodic state saving techniques in time warp simulators , 1995, PADS.

[11]  Ganesh Gopalakrishnan,et al.  Design and Evaluation of the Rollback Chip: Special Purpose Hardware for Time Warp , 1992, IEEE Trans. Computers.

[12]  Yi-Bing Lin,et al.  Selecting the checkpoint interval in time warp simulation , 1993, PADS '93.

[13]  Philip A. Wilsey,et al.  Adaptive checkpoint intervals in an optimistically synchronised parallel digital system simulator , 1993, VLSI.

[14]  K. Mani Chandy,et al.  Asynchronous distributed simulation via a sequence of parallel computations , 1981, CACM.

[15]  Satish K. Tripathi,et al.  Parallel and distributed simulation of discrete event systems , 1994 .

[16]  David Bruce.  The treatment of state in optimistic systems , 1995, PADS.

[17]  Herbert Bauer,et al.  Reducing Rollback Overhead In Time-warp Based Distributed Simulation With Optimized Incremental State Saving , 1993, [1993] Proceedings 26th Annual Simulation Symposium.

[18]  Francesco Quaglia,et al.  Nonblocking Checkpointing for Optimistic Parallel Simulation: Description and an Implementation , 2003, IEEE Trans. Parallel Distributed Syst..

[19]  David M. Nicol,et al.  The impact of adding aggressiveness to a non-aggressive windowing protocol , 1993, WSC '93.

[20]  David Bryan,et al.  Combinational profiles of sequential benchmark circuits , 1989, IEEE International Symposium on Circuits and Systems,.

[21]  Wayne M. Loucks,et al.  Effects of the checkpoint interval on time and space in time warp , 1994, TOMC.

[22]  David R. Jefferson,et al.  Virtual time , 1985, ICPP.

[23]  Jeff S. Steinman,et al.  Breathing Time Warp , 1993, PADS '93.

[24]  Richard M. Fujimoto,et al.  The MIMDIX Environment for Parallel Simulation , 1993, J. Parallel Distributed Comput..

[25]  K. Mani Chandy,et al.  Distributed Simulation: A Case Study in Design and Verification of Distributed Programs , 1979, IEEE Transactions on Software Engineering.

[26]  Rajive L. Bagrodia,et al.  A unified framework for conservative and optimistic distributed simulation , 1994, PADS '94.