xref: /petsc/src/sys/classes/viewer/interface/dupl.c (revision dbbe0bcd3f3a8fbab5a45420dc06f8387e5764c6)
15c6c1daeSBarry Smith 
2af0996ceSBarry Smith #include <petsc/private/viewerimpl.h>  /*I "petscviewer.h" I*/
35c6c1daeSBarry Smith 
4b3fa1ec5SBarry Smith /*@C
53f08860eSBarry Smith    PetscViewerGetSubViewer - Creates a new PetscViewer (same type as the old)
63f08860eSBarry Smith     that lives on a subcommunicator
75c6c1daeSBarry Smith 
85c6c1daeSBarry Smith     Collective on PetscViewer
95c6c1daeSBarry Smith 
105c6c1daeSBarry Smith    Input Parameter:
113f08860eSBarry Smith .  viewer - the PetscViewer to be reproduced
125c6c1daeSBarry Smith 
135c6c1daeSBarry Smith    Output Parameter:
145c6c1daeSBarry Smith .  outviewer - new PetscViewer
155c6c1daeSBarry Smith 
165c6c1daeSBarry Smith    Level: advanced
175c6c1daeSBarry Smith 
1895452b02SPatrick Sanan    Notes:
19a62913d3SBarry Smith     The output of the subviewers is synchronized against the original viewer. For example, if a
20a62913d3SBarry Smith     viewer on two MPI ranks is decomposed into two subviewers, the output from the first viewer is
21a62913d3SBarry Smith     all printed before the output from the second viewer. You must call PetscViewerFlush() after
22a62913d3SBarry Smith     the call to PetscViewerRestoreSubViewer().
23a62913d3SBarry Smith 
24a62913d3SBarry Smith     Call PetscViewerRestoreSubViewer() to destroy this PetscViewer, NOT PetscViewerDestroy()
255c6c1daeSBarry Smith 
265c6c1daeSBarry Smith      This is most commonly used to view a sequential object that is part of a
275c6c1daeSBarry Smith     parallel object. For example block Jacobi PC view could use this to obtain a
285c6c1daeSBarry Smith     PetscViewer that is used with the sequential KSP on one block of the preconditioner.
295c6c1daeSBarry Smith 
30e5afcf28SBarry Smith     Between the calls to PetscViewerGetSubViewer() and PetscViewerRestoreSubViewer() the original
31e5afcf28SBarry Smith     viewer should not be used
32e5afcf28SBarry Smith 
33e5afcf28SBarry Smith     PETSCVIEWERDRAW and PETSCVIEWERBINARY only support returning a singleton viewer on rank 0,
34e5afcf28SBarry Smith     all other ranks will return a NULL viewer
35e5afcf28SBarry Smith 
36e5afcf28SBarry Smith   Developer Notes:
37e5afcf28SBarry Smith     There is currently incomplete error checking that the user does not use the original viewer between the
38e5afcf28SBarry Smith     the calls to PetscViewerGetSubViewer() and PetscViewerRestoreSubViewer(). If the user does there
39e5afcf28SBarry Smith     could be errors in the viewing that go undetected or crash the code.
40e5afcf28SBarry Smith 
41a62913d3SBarry Smith     It would be nice if the call to PetscViewerFlush() was not required and was handled by
42a62913d3SBarry Smith     PetscViewerRestoreSubViewer()
43a62913d3SBarry Smith 
44db781477SPatrick Sanan .seealso: `PetscViewerSocketOpen()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewerRestoreSubViewer()`
455c6c1daeSBarry Smith @*/
463f08860eSBarry Smith PetscErrorCode  PetscViewerGetSubViewer(PetscViewer viewer,MPI_Comm comm,PetscViewer *outviewer)
475c6c1daeSBarry Smith {
485c6c1daeSBarry Smith   PetscFunctionBegin;
495c6c1daeSBarry Smith   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
50064a246eSJacob Faibussowitsch   PetscValidPointer(outviewer,3);
51*dbbe0bcdSBarry Smith   PetscUseTypeMethod(viewer,getsubviewer ,comm,outviewer);
525c6c1daeSBarry Smith   PetscFunctionReturn(0);
535c6c1daeSBarry Smith }
545c6c1daeSBarry Smith 
55b3fa1ec5SBarry Smith /*@C
563f08860eSBarry Smith    PetscViewerRestoreSubViewer - Restores a new PetscViewer obtained with PetscViewerGetSubViewer().
575c6c1daeSBarry Smith 
585c6c1daeSBarry Smith     Collective on PetscViewer
595c6c1daeSBarry Smith 
605c6c1daeSBarry Smith    Input Parameters:
613f08860eSBarry Smith +  viewer - the PetscViewer that was reproduced
625c6c1daeSBarry Smith -  outviewer - new PetscViewer
635c6c1daeSBarry Smith 
645c6c1daeSBarry Smith    Level: advanced
655c6c1daeSBarry Smith 
6695452b02SPatrick Sanan    Notes:
6795452b02SPatrick Sanan     Call PetscViewerGetSubViewer() to get this PetscViewer, NOT PetscViewerCreate()
685c6c1daeSBarry Smith 
69db781477SPatrick Sanan .seealso: `PetscViewerSocketOpen()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewerGetSubViewer()`
705c6c1daeSBarry Smith @*/
713f08860eSBarry Smith PetscErrorCode  PetscViewerRestoreSubViewer(PetscViewer viewer,MPI_Comm comm,PetscViewer *outviewer)
725c6c1daeSBarry Smith {
735c6c1daeSBarry Smith   PetscFunctionBegin;
745c6c1daeSBarry Smith   PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);
75ffc4695bSBarry Smith 
76*dbbe0bcdSBarry Smith   PetscUseTypeMethod(viewer,restoresubviewer ,comm,outviewer);
775c6c1daeSBarry Smith   PetscFunctionReturn(0);
785c6c1daeSBarry Smith }
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