8.5.3 Graph constructor 8.5.4 8.5.5 op Function 8.5.6 logy Ing rdinate 8.5.7 of Cart Functions 8 6 Neighborhood Collec 8.6.i Neighborhood Gather 8.6.2 Neighbo 8> 87.1 Nonblocking 8.7.2 ersistent Ne 8.9 An Application 9 MPI Environmental Management 451 9.1 Implementation Information 4 9.1.1 Version Inquiries 012 ental Inquiries 45 Tag values 453 Host Rank 453 IO Rank 454 Clock Synchronization 454 sor Nam 9.2 455 9.3 Error Handling 458 9.3.1 Error 461 9.3.2 Error Handlers for Windows 463 9.3.3 Handlers for Files 465 9.3.4 Handler fo 466 9.3.5 and Retrievi ing Er ror Strings 463 04 Erro d Classe 469 9.5 and Error Hand 9.6 10 The Info Object 479 11 Process Initialization,Creation,and Management 11.2 The World Mode 11.2.1 Starting MPI Processes 11.2.2 Finalizing MPI . 11.2.3 Determining Whether MPI Has Been Initialized When Using the World Model.. 11.2.4 Allowing User Functions at MPI Finalization 48 ll.3 The Sessions Model..················ 4 48.5.3 Graph Constructor . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 8.5.4 Distributed Graph Constructor . . . . . . . . . . . . . . . . . . . . 396 8.5.5 Topology Inquiry Functions . . . . . . . . . . . . . . . . . . . . . . 403 8.5.6 Cartesian Shift Coordinates . . . . . . . . . . . . . . . . . . . . . . 412 8.5.7 Partitioning of Cartesian Structures . . . . . . . . . . . . . . . . . 413 8.5.8 Low-Level Topology Functions . . . . . . . . . . . . . . . . . . . . 414 8.6 Neighborhood Collective Communication . . . . . . . . . . . . . . . . . . . 416 8.6.1 Neighborhood Gather . . . . . . . . . . . . . . . . . . . . . . . . . 417 8.6.2 Neighbor Alltoall . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 8.7 Nonblocking Neighborhood Communication . . . . . . . . . . . . . . . . . 429 8.7.1 Nonblocking Neighborhood Gather . . . . . . . . . . . . . . . . . . 429 8.7.2 Nonblocking Neighborhood Alltoall . . . . . . . . . . . . . . . . . 432 8.8 Persistent Neighborhood Communication . . . . . . . . . . . . . . . . . . . 437 8.8.1 Persistent Neighborhood Gather . . . . . . . . . . . . . . . . . . . 438 8.8.2 Persistent Neighborhood Alltoall . . . . . . . . . . . . . . . . . . . 441 8.9 An Application Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 9 MPI Environmental Management 451 9.1 Implementation Information . . . . . . . . . . . . . . . . . . . . . . . . . . 451 9.1.1 Version Inquiries . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 9.1.2 Environmental Inquiries . . . . . . . . . . . . . . . . . . . . . . . . 453 Tag Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 Host Rank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 IO Rank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454 Clock Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . 454 Inquire Processor Name . . . . . . . . . . . . . . . . . . . . . . . . 454 9.2 Memory Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 9.3 Error Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458 9.3.1 Error Handlers for Communicators . . . . . . . . . . . . . . . . . . 461 9.3.2 Error Handlers for Windows . . . . . . . . . . . . . . . . . . . . . 463 9.3.3 Error Handlers for Files . . . . . . . . . . . . . . . . . . . . . . . . 465 9.3.4 Error Handlers for Sessions . . . . . . . . . . . . . . . . . . . . . . 466 9.3.5 Freeing Errorhandlers and Retrieving Error Strings . . . . . . . . 468 9.4 Error Codes and Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469 9.5 Error Classes, Error Codes, and Error Handlers . . . . . . . . . . . . . . . 473 9.6 Timers and Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . 477 10 The Info Object 479 11 Process Initialization, Creation, and Management 487 11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 11.2 The World Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488 11.2.1 Starting MPI Processes . . . . . . . . . . . . . . . . . . . . . . . . 488 11.2.2 Finalizing MPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494 11.2.3 Determining Whether MPI Has Been Initialized When Using the World Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497 11.2.4 Allowing User Functions at MPI Finalization . . . . . . . . . . . . 498 11.3 The Sessions Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499 x