Follow up: running with valgrind shows the following issues….is this a bug in PETSc?
==5216== Use of uninitialised value of size 8 ==5216== at 0x49ED69C: f90array1dcreatefortranaddr_ (f90_fwrap.F90:52) ==5216== by 0x4D7EA94: F90Array1dCreate (f90_cwrap.c:140) ==5216== by 0x6B7295A: dmcompositegetglobaliss_ (zfddaf.c:70) ==5216== by 0x1095C8: MAIN__ (test.F90:35) ==5216== by 0x1096AC: main (test.F90:4) ==5216== Uninitialised value was created by a stack allocation ==5216== at 0x109219: MAIN__ (test.F90:1) ==5216== ==5216== Invalid write of size 8 ==5216== at 0x49ED69C: f90array1dcreatefortranaddr_ (f90_fwrap.F90:52) ==5216== by 0x4D7EA94: F90Array1dCreate (f90_cwrap.c:140) ==5216== by 0x6B7295A: dmcompositegetglobaliss_ (zfddaf.c:70) ==5216== by 0x1095C8: MAIN__ (test.F90:35) ==5216== by 0x1096AC: main (test.F90:4) ==5216== Address 0x20 is not stack'd, malloc'd or (recently) free'd ==5216== Thanks, Randyt > On Jun 17, 2025, at 3:39 PM, Randall Mackie <rlmackie...@gmail.com> wrote: > > Dear Petsc users - > > I am trying to upgrade my code to petsc-3.23 (from 3.19), and I seem to have > run into a problem with DMCompositeGetGlobalISs. > > The example program listed on the man page for DMCompositeGetGlobalISs, > https://urldefense.us/v3/__https://petsc.org/release/src/snes/tutorials/ex73f90t.F90.html__;!!G_uCfscf7eWS!bm0O_rjMssXigJJ70W-MVHCpKJyZbomZ-493v0TAJHAGdJgTS8zhtJTfPhN84ty778IefJ_7k2D6EqiHLBIIsoR5QA$ > , seems to indicate that a call to DMCompositeGetGlobalISs does not need to > allocate the IS pointer and you just pass it directly to > DMCompositeGetGlobalISs. > > If I compile and run the simple attached test program (say on 2 processes), I > get the following error: > > [0]PETSC ERROR: > ------------------------------------------------------------------------ > [0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, > probably memory access out of range > [0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger > [0]PETSC ERROR: or see > https://urldefense.us/v3/__https://petsc.org/release/faq/*valgrind__;Iw!!G_uCfscf7eWS!bm0O_rjMssXigJJ70W-MVHCpKJyZbomZ-493v0TAJHAGdJgTS8zhtJTfPhN84ty778IefJ_7k2D6EqiHLBJU3XEgSQ$ > and > https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!bm0O_rjMssXigJJ70W-MVHCpKJyZbomZ-493v0TAJHAGdJgTS8zhtJTfPhN84ty778IefJ_7k2D6EqiHLBJR1nT-VA$ > > [0]PETSC ERROR: --------------------- Stack Frames > ------------------------------------ > [0]PETSC ERROR: The line numbers in the error traceback may not be exact. > [0]PETSC ERROR: #1 F90Array1dCreate() at > /home/rmackie/PETSc/petsc-3.23.3/src/sys/ftn-custom/f90_cwrap.c:123 > application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0 > > > If I uncomment the line to allocate the pointer, I get a very long traceback > with lots of error messages. > > What is the correct way to use DMCompositeGetGlobalISs in Fortran? With or > without the pointer allocation, and what is the right way to do this without > the errors it seems to generate? > > Thanks, > > Randy Mackie > > <test.F90>
