Oh interesting, so I need to add those extra brackets around my class object
and function calls. I thought the destructor is automatically at Finalize.
Thanks!
Yuyun
-----Original Message-----
From: Jed Brown <j...@jedbrown.org>
Sent: Sunday, March 3, 2019 2:19 PM
To: Yuyun Yang <yyan...@stanford.edu>; Matthew Knepley <knep...@gmail.com>
Cc: petsc-users@mcs.anl.gov
Subject: Re: [petsc-users] AddressSanitizer: attempting free on address which
was not malloc()-ed
If you run this with MPICH, it prints
Attempting to use an MPI routine after finalizing MPICH
You need to ensure that the C++ class destructor is called before
PetscFinalize. For example, like this:
diff --git i/test_domain.cpp w/test_domain.cpp index 0cfe22f..23545f2 100644
--- i/test_domain.cpp
+++ w/test_domain.cpp
@@ -8,11 +8,12 @@ int main(int argc, char **argv) {
PetscErrorCode ierr = 0;
PetscInitialize(&argc, &argv, NULL, NULL);
- Domain d;
+ {
+ Domain d;
- ierr = d.setFields(); CHKERRQ(ierr);
- ierr = d.setScatters(); CHKERRQ(ierr);
-
+ ierr = d.setFields(); CHKERRQ(ierr);
+ ierr = d.setScatters(); CHKERRQ(ierr); }
PetscFinalize();
return ierr;
}
Yuyun Yang via petsc-users <petsc-users@mcs.anl.gov> writes:
> Yes, please see the attached files for a minimal example. Thanks a lot!
>
> Best regards,
> Yuyun
>
> From: Matthew Knepley <knep...@gmail.com>
> Sent: Sunday, March 3, 2019 12:46 PM
> To: Yuyun Yang <yyan...@stanford.edu>
> Cc: Zhang, Junchao <jczh...@mcs.anl.gov>; petsc-users@mcs.anl.gov
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
> On Sun, Mar 3, 2019 at 3:05 PM Yuyun Yang
> <yyan...@stanford.edu<mailto:yyan...@stanford.edu>> wrote:
> Actually, I tried just creating a domain object (since the address sanitizer
> was complaining about that code to start with). Simply creating that object
> gave me a core dump, so I suppose the issue must be there. I got the
> following message when running the code with -objects_dump flag on the
> command line, but couldn’t find a problem with the code (I’ve attached it
> here with only the relevant functions).
>
> I think what we are going to need from you is a minimal example that
> has the error. I am guessing you have a logic bug in the C++, which we cannot
> debug by looking.
>
> Thanks,
>
> Matt
>
> Thanks a lot for your help!
>
> The following objects were never freed
> -----------------------------------------
> [0] Vec seq y
> [0] VecCreate() in
> /home/yyy910805/petsc/src/vec/vec/interface/veccreate.c
> [0] Vec seq Vec_0x84000000_0
> [0] VecCreate() in
> /home/yyy910805/petsc/src/vec/vec/interface/veccreate.c
> [0] Vec seq Vec_0x84000000_1
> [0] VecCreate() in
> /home/yyy910805/petsc/src/vec/vec/interface/veccreate.c
> [0] VecScatter seq VecScatter_0x84000000_2
> [0] VecScatterCreate() in
> /home/yyy910805/petsc/src/vec/vscat/interface/vscreate.c
> [0] VecScatter seq VecScatter_0x84000000_3
> [0] VecScatterCreate() in
> /home/yyy910805/petsc/src/vec/vscat/interface/vscreate.c
> [0] VecScatter seq VecScatter_0x84000000_4
> [0] VecScatterCreate() in
> /home/yyy910805/petsc/src/vec/vscat/interface/vscreate.c
> [0] VecScatter seq VecScatter_0x84000000_5
> [0] VecScatterCreate() in
> /home/yyy910805/petsc/src/vec/vscat/interface/vscreate.c
> Attempting to use an MPI routine after finalizing MPICH
>
> ----------------------------------------------------------------------
> ----------------------------------------------------------------------
> -----
> From: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>>
> Sent: Sunday, March 3, 2019 11:28 AM
> To: Yuyun Yang <yyan...@stanford.edu<mailto:yyan...@stanford.edu>>
> Cc: Zhang, Junchao <jczh...@mcs.anl.gov<mailto:jczh...@mcs.anl.gov>>;
> petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
> On Sun, Mar 3, 2019 at 1:03 PM Yuyun Yang via petsc-users
> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> wrote:
> I tried compiling without the sanitizer and running on valgrind. Got a bunch
> of errors “Uninitialised value was created by a stack allocation at 0x41B280:
> ComputeVel_qd::computeVel(double*, double, int&, int)”.
>
> There is no memory management code here, so other parts of the code must be
> relevant.
>
> Thanks,
>
> Matt
>
>
> HEAP SUMMARY:
> ==74== in use at exit: 96,637 bytes in 91 blocks
> ==74== total heap usage: 47,774 allocs, 47,522 frees, 308,253,653 bytes
> allocated
> LEAK SUMMARY:
> ==74== definitely lost: 0 bytes in 0 blocks
> ==74== indirectly lost: 0 bytes in 0 blocks
> ==74== possibly lost: 0 bytes in 0 blocks
> ==74== still reachable: 96,637 bytes in 91 blocks
> ==74== suppressed: 0 bytes in 0 blocks
>
> The error is located in the attached code (I’ve extracted only the relevant
> functions), but I couldn’t figure out what is wrong. Is this causing the
> memory corruption/double free error that happens when I execute the code?
>
> Thanks a lot for your help.
>
> Best regards,
> Yuyun
>
> From: Zhang, Junchao <jczh...@mcs.anl.gov<mailto:jczh...@mcs.anl.gov>>
> Sent: Friday, March 1, 2019 7:36 AM
> To: Yuyun Yang <yyan...@stanford.edu<mailto:yyan...@stanford.edu>>
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
>
> On Fri, Mar 1, 2019 at 1:02 AM Yuyun Yang
> <yyan...@stanford.edu<mailto:yyan...@stanford.edu>> wrote:
> Actually, I also saw a line at the beginning of valgrind saying "shadow
> memory range interleaves with an existing memory mapping. ASan cannot proceed
> properly. ABORTING." I guess the code didn't really run through valgrind
> since it aborted. Should I remove the address sanitizer flag when compiling?
> From the message, it seems ASan (not valgrind) aborted. You can try to
> compile without sanitizer and then run with valgrind. If no problem, then it
> is probably a sanitizer issue.
>
>
> Get Outlook for iOS<https://aka.ms/o0ukef>
> ________________________________
> From: Yuyun Yang
> Sent: Thursday, February 28, 2019 10:54:57 PM
> To: Zhang, Junchao
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
> Hmm, still getting the same error from address sanitizer even though valgrind
> shows no errors and no leaks are possible.
>
> Should I ignore that error? My results did run alright.
>
> Best,
> Yuyun
>
> Get Outlook for iOS<https://aka.ms/o0ukef>
> ________________________________
> From: Zhang, Junchao <jczh...@mcs.anl.gov<mailto:jczh...@mcs.anl.gov>>
> Sent: Wednesday, February 27, 2019 8:27:17 PM
> To: Yuyun Yang
> Cc: Matthew Knepley;
> petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
> Try the following to see if you can catch the bug easily: 1) Get error
> code for each petsc function and check it with CHKERRQ; 2) Link your
> code with a petsc library with debugging enabled (configured with
> --with-debugging=1); 3) Run your code with valgrind
>
> --Junchao Zhang
>
>
> On Wed, Feb 27, 2019 at 9:04 PM Yuyun Yang
> <yyan...@stanford.edu<mailto:yyan...@stanford.edu>> wrote:
> Hi Junchao,
>
> This code actually involves a lot of classes and is pretty big. Might be an
> overkill for me to send everything to you. I'd like to know if I see this
> sort of error message, which points to this domain file, is it possible that
> the problem happens in another file (whose operations are linked to this
> one)? If so, I'll debug a little more and maybe send you more useful
> information later.
>
> Best regards,
> Yuyun
>
> Get Outlook for iOS<https://aka.ms/o0ukef>
> ________________________________
> From: Zhang, Junchao <jczh...@mcs.anl.gov<mailto:jczh...@mcs.anl.gov>>
> Sent: Wednesday, February 27, 2019 6:24:13 PM
> To: Yuyun Yang
> Cc: Matthew Knepley;
> petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
> Could you provide a compilable and runnable test so I can try it?
> --Junchao Zhang
>
>
> On Wed, Feb 27, 2019 at 7:34 PM Yuyun Yang
> <yyan...@stanford.edu<mailto:yyan...@stanford.edu>> wrote:
> Thanks, I fixed that, but I’m not actually calling the testScatters()
> function in my implementation (in the constructor, the only functions I
> called are setFields and setScatters). So the problem couldn’t have been that?
>
> Best,
> Yuyun
>
> From: Zhang, Junchao <jczh...@mcs.anl.gov<mailto:jczh...@mcs.anl.gov>>
> Sent: Wednesday, February 27, 2019 10:50 AM
> To: Yuyun Yang <yyan...@stanford.edu<mailto:yyan...@stanford.edu>>
> Cc: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>>;
> petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
>
> On Wed, Feb 27, 2019 at 10:41 AM Yuyun Yang via petsc-users
> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> wrote:
> I called VecDestroy() in the destructor for this object – is that not the
> right way to do it?
> In Domain::testScatters(), you have many VecDuplicate(,&out), You need
> to VecDestroy(&out) before doing new VecDuplicate(,&out); How do I implement
> CHECK ALL RETURN CODES?
> For each PETSc function, do ierr = ...; CHKERRQ(ierr);
>
> From: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>>
> Sent: Wednesday, February 27, 2019 7:24 AM
> To: Yuyun Yang <yyan...@stanford.edu<mailto:yyan...@stanford.edu>>
> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>
> Subject: Re: [petsc-users] AddressSanitizer: attempting free on
> address which was not malloc()-ed
>
> You call VecDuplicate() a bunch, but VecDestroy() only once in the bottom
> function. This is wrong.
> Also, CHECK ALL RETURN CODES. This is the fastest way to find errors.
>
> Matt
>
> On Wed, Feb 27, 2019 at 2:06 AM Yuyun Yang via petsc-users
> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> wrote:
> Hello team,
>
> I ran into the address sanitizer error that I hope you could help me with. I
> don’t really know what’s wrong with the way the code frees memory. The
> relevant code file is attached. The line number following domain.cpp
> specifically referenced to the vector _q, which seems a little odd, since
> some other vectors are constructed and freed the same way.
>
> ==1719==ERROR: AddressSanitizer: attempting free on address which was not
> malloc()-ed: 0x61f0000076c0 in thread T0
> #0 0x7fbf195282ca in __interceptor_free
> (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x982ca)
> #1 0x7fbf1706f895 in PetscFreeAlign
> /home/yyy910805/petsc/src/sys/memory/mal.c:87
> #2 0x7fbf1731a898 in VecDestroy_Seq
> /home/yyy910805/petsc/src/vec/vec/impls/seq/bvec2.c:788
> #3 0x7fbf1735f795 in VecDestroy
> /home/yyy910805/petsc/src/vec/vec/interface/vector.c:408
> #4 0x40dd0a in Domain::~Domain()
> /home/yyy910805/scycle/source/domain.cpp:132
> #5 0x40b479 in main /home/yyy910805/scycle/source/main.cpp:242
> #6 0x7fbf14d2082f in __libc_start_main
> (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
> #7 0x4075d8 in _start
> (/home/yyy910805/scycle/source/main+0x4075d8)
>
> 0x61f0000076c0 is located 1600 bytes inside of 3220-byte region
> [0x61f000007080,0x61f000007d14) allocated by thread T0 here:
> #0 0x7fbf19528b32 in __interceptor_memalign
> (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98b32)
> #1 0x7fbf1706f7e0 in PetscMallocAlign
> /home/yyy910805/petsc/src/sys/memory/mal.c:41
> #2 0x7fbf17073022 in PetscTrMallocDefault
> /home/yyy910805/petsc/src/sys/memory/mtr.c:183
> #3 0x7fbf170710a1 in PetscMallocA
> /home/yyy910805/petsc/src/sys/memory/mal.c:397
> #4 0x7fbf17326fb0 in VecCreate_Seq
> /home/yyy910805/petsc/src/vec/vec/impls/seq/bvec3.c:35
> #5 0x7fbf1736f560 in VecSetType
> /home/yyy910805/petsc/src/vec/vec/interface/vecreg.c:51
> #6 0x7fbf1731afae in VecDuplicate_Seq
> /home/yyy910805/petsc/src/vec/vec/impls/seq/bvec2.c:807
> #7 0x7fbf1735eff7 in VecDuplicate
> /home/yyy910805/petsc/src/vec/vec/interface/vector.c:379
> #8 0x4130de in Domain::setFields()
> /home/yyy910805/scycle/source/domain.cpp:431
> #9 0x40c60a in Domain::Domain(char const*)
> /home/yyy910805/scycle/source/domain.cpp:57
> #10 0x40b433 in main /home/yyy910805/scycle/source/main.cpp:242
> #11 0x7fbf14d2082f in __libc_start_main
> (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
>
> SUMMARY: AddressSanitizer: bad-free ??:0 __interceptor_free
> ==1719==ABORTING
>
> Thanks very much!
> Yuyun
>
>
> --
> What most experimenters take for granted before they begin their experiments
> is infinitely more interesting than any results to which their experiments
> lead.
> -- Norbert Wiener
>
> https://www.cse.buffalo.edu/~knepley/<http://www.cse.buffalo.edu/~knep
> ley/>
>
>
> --
> What most experimenters take for granted before they begin their experiments
> is infinitely more interesting than any results to which their experiments
> lead.
> -- Norbert Wiener
>
> https://www.cse.buffalo.edu/~knepley/<http://www.cse.buffalo.edu/~knep
> ley/>
>
>
> --
> What most experimenters take for granted before they begin their experiments
> is infinitely more interesting than any results to which their experiments
> lead.
> -- Norbert Wiener
>
> https://www.cse.buffalo.edu/~knepley/<http://www.cse.buffalo.edu/~knep
> ley/>
> #include "domain.hpp"
>
> using namespace std;
>
> Domain::Domain()
> : _sbpType("mfc_coordTrans"),_Ny(201),_Nz(1),_Ly(30),_Lz(30),
> _q(NULL),_r(NULL),_y(NULL),_z(NULL),_y0(NULL),_z0(NULL),_dq(-1),_dr(-1),
> _bCoordTrans(5)
> {
> if (_Ny > 1) {
> _dq = 1.0 / (_Ny - 1.0);
> }
> else {
> _dq = 1;
> }
>
> if (_Nz > 1) {
> _dr = 1.0 / (_Nz - 1.0);
> }
> else {
> _dr = 1;
> }
> }
>
> // destructor
> Domain::~Domain()
> {
> // free memory
> VecDestroy(&_q);
> VecDestroy(&_r);
> VecDestroy(&_y);
> VecDestroy(&_z);
> VecDestroy(&_y0);
> VecDestroy(&_z0);
>
> // set map iterator, free memory from VecScatter
> map<string,VecScatter>::iterator it;
> for (it = _scatters.begin(); it != _scatters.end(); it++) {
> VecScatterDestroy(&(it->second));
> }
> }
>
> // construct coordinate transform, setting vectors q, r, y, z
> PetscErrorCode Domain::setFields() {
> PetscErrorCode ierr = 0;
>
> // generate vector _y with size _Ny*_Nz
> ierr = VecCreate(PETSC_COMM_WORLD,&_y); CHKERRQ(ierr);
> ierr = VecSetSizes(_y,PETSC_DECIDE,_Ny*_Nz); CHKERRQ(ierr);
> ierr = VecSetFromOptions(_y); CHKERRQ(ierr);
> ierr = PetscObjectSetName((PetscObject) _y, "y"); CHKERRQ(ierr);
>
> // duplicate _y into _z, _q, _r
> ierr = VecDuplicate(_y,&_z); CHKERRQ(ierr);
> ierr = PetscObjectSetName((PetscObject) _z, "z"); CHKERRQ(ierr);
> ierr = VecDuplicate(_y,&_q); CHKERRQ(ierr);
> ierr = PetscObjectSetName((PetscObject) _q, "q"); CHKERRQ(ierr);
> ierr = VecDuplicate(_y,&_r); CHKERRQ(ierr);
> ierr = PetscObjectSetName((PetscObject) _r, "r"); CHKERRQ(ierr);
>
> // construct coordinate transform
> PetscInt Ii,Istart,Iend,Jj = 0;
> PetscScalar *y,*z,*q,*r;
> ierr = VecGetOwnershipRange(_q,&Istart,&Iend);CHKERRQ(ierr);
>
> // return pointers to local data arrays (the processor's portion of vector
> data)
> ierr = VecGetArray(_y,&y); CHKERRQ(ierr);
> ierr = VecGetArray(_z,&z); CHKERRQ(ierr);
> ierr = VecGetArray(_q,&q); CHKERRQ(ierr);
> ierr = VecGetArray(_r,&r); CHKERRQ(ierr);
>
> // set vector entries for q, r (coordinate transform) and y, z (no
> transform)
> for (Ii=Istart; Ii<Iend; Ii++) {
> q[Jj] = _dq*(Ii/_Nz);
> r[Jj] = _dr*(Ii-_Nz*(Ii/_Nz));
>
> // matrix-based, fully compatible, allows curvilinear coordinate
> transformation
> if (_sbpType.compare("mfc_coordTrans") ) {
> y[Jj] = (_dq*_Ly)*(Ii/_Nz);
> z[Jj] = (_dr*_Lz)*(Ii-_Nz*(Ii/_Nz));
> }
> else {
> // hardcoded transformation (not available for z)
> if (_bCoordTrans > 0) {
> y[Jj] = _Ly * sinh(_bCoordTrans * q[Jj]) / sinh(_bCoordTrans);
> }
> // no transformation
> y[Jj] = q[Jj]*_Ly;
> z[Jj] = r[Jj]*_Lz;
> }
> Jj++;
> }
>
> // restore arrays
> ierr = VecRestoreArray(_y,&y); CHKERRQ(ierr);
> ierr = VecRestoreArray(_z,&z); CHKERRQ(ierr);
> ierr = VecRestoreArray(_q,&q); CHKERRQ(ierr);
> ierr = VecRestoreArray(_r,&r); CHKERRQ(ierr);
>
> return ierr;
> }
>
>
> // scatters values from one vector to another PetscErrorCode
> Domain::setScatters() {
> PetscErrorCode ierr = 0;
>
> ierr = VecCreate(PETSC_COMM_WORLD,&_y0); CHKERRQ(ierr);
> ierr = VecSetSizes(_y0,PETSC_DECIDE,_Nz); CHKERRQ(ierr);
> ierr = VecSetFromOptions(_y0); CHKERRQ(ierr);
> ierr = VecSet(_y0,0.0); CHKERRQ(ierr);
>
> ierr = VecCreate(PETSC_COMM_WORLD,&_z0); CHKERRQ(ierr);
> ierr = VecSetSizes(_z0,PETSC_DECIDE,_Ny); CHKERRQ(ierr);
> ierr = VecSetFromOptions(_z0); CHKERRQ(ierr);
> ierr = VecSet(_z0,0.0); CHKERRQ(ierr);
>
> PetscInt *indices;
> IS is;
> ierr = PetscMalloc1(_Nz,&indices); CHKERRQ(ierr);
>
> // we want to scatter from index 0 to _Nz - 1, i.e. take the first _Nz
> components of the vector to scatter from
> for (PetscInt Ii = 0; Ii<_Nz; Ii++) {
> indices[Ii] = Ii;
> }
>
> ierr = ISCreateGeneral(PETSC_COMM_WORLD, _Nz, indices, PETSC_COPY_VALUES,
> &is); CHKERRQ(ierr);
> ierr = VecScatterCreate(_y, is, _y0, is, &_scatters["body2L"]);
> CHKERRQ(ierr);
>
> // free memory
> ierr = PetscFree(indices); CHKERRQ(ierr);
> ierr = ISDestroy(&is); CHKERRQ(ierr);
>
>
> //===============================================================================
> // set up scatter context to take values for y = Ly from body field and put
> them on a Vec of size Nz
> PetscInt *fi;
> IS isf;
> ierr = PetscMalloc1(_Nz,&fi); CHKERRQ(ierr);
>
> for (PetscInt Ii = 0; Ii<_Nz; Ii++) {
> fi[Ii] = Ii + (_Ny*_Nz-_Nz);
> }
> ierr = ISCreateGeneral(PETSC_COMM_WORLD, _Nz, fi, PETSC_COPY_VALUES,
> &isf); CHKERRQ(ierr);
>
> PetscInt *ti;
> IS ist;
> ierr = PetscMalloc1(_Nz,&ti); CHKERRQ(ierr);
> for (PetscInt Ii = 0; Ii<_Nz; Ii++) {
> ti[Ii] = Ii;
> }
> ierr = ISCreateGeneral(PETSC_COMM_WORLD, _Nz, ti, PETSC_COPY_VALUES, &ist);
> CHKERRQ(ierr);
> ierr = VecScatterCreate(_y, isf, _y0, ist, &_scatters["body2R"]);
> CHKERRQ(ierr);
>
> // free memory
> ierr = PetscFree(fi); CHKERRQ(ierr);
> ierr = PetscFree(ti); CHKERRQ(ierr);
> ierr = ISDestroy(&isf); CHKERRQ(ierr);
> ierr = ISDestroy(&ist); CHKERRQ(ierr);
>
>
>
> //==============================================================================
>
> IS isf2;
> ierr = ISCreateStride(PETSC_COMM_WORLD, _Ny, 0, _Nz, &isf2);
> CHKERRQ(ierr);
>
> PetscInt *ti2;
> IS ist2;
> ierr = PetscMalloc1(_Ny,&ti2); CHKERRQ(ierr);
>
> for (PetscInt Ii=0; Ii<_Ny; Ii++) {
> ti2[Ii] = Ii;
> }
> ierr = ISCreateGeneral(PETSC_COMM_WORLD, _Ny, ti2, PETSC_COPY_VALUES,
> &ist2); CHKERRQ(ierr);
> ierr = VecScatterCreate(_y, isf2, _z0, ist2, &_scatters["body2T"]);
> CHKERRQ(ierr);
>
> // free memory
> ierr = PetscFree(ti2); CHKERRQ(ierr);
> ierr = ISDestroy(&isf2); CHKERRQ(ierr);
> ierr = ISDestroy(&ist2); CHKERRQ(ierr);
>
>
>
> //==============================================================================
> IS isf3;
> ierr = ISCreateStride(PETSC_COMM_WORLD, _Ny, _Nz - 1, _Nz, &isf3);
> CHKERRQ(ierr);
>
> PetscInt *ti3;
> IS ist3;
> ierr = PetscMalloc1(_Ny,&ti3); CHKERRQ(ierr);
> for (PetscInt Ii = 0; Ii<_Ny; Ii++) {
> ti3[Ii] = Ii;
> }
> ierr = ISCreateGeneral(PETSC_COMM_WORLD, _Ny, ti3, PETSC_COPY_VALUES,
> &ist3); CHKERRQ(ierr);
> ierr = VecScatterCreate(_y, isf3, _z0, ist3, &_scatters["body2B"]);
> CHKERRQ(ierr);
>
> // free memory
> ierr = PetscFree(ti3); CHKERRQ(ierr);
> ierr = ISDestroy(&isf3); CHKERRQ(ierr);
> ierr = ISDestroy(&ist3); CHKERRQ(ierr);
>
> return ierr;
> }
> #include "domain.hpp"
>
> using namespace std;
>
> // creates a domain object
> int main(int argc, char **argv) {
>
> PetscErrorCode ierr = 0;
> PetscInitialize(&argc, &argv, NULL, NULL);
>
> Domain d;
>
> ierr = d.setFields(); CHKERRQ(ierr);
> ierr = d.setScatters(); CHKERRQ(ierr);
>
> PetscFinalize();
> return ierr;
> }
