I am trying to read some parameters into my PETSc simulation using
fgets, and am getting a strange error. It appears that fgets and
sscanf are working since the proper values are read into the
simulation, but it throws an error anyways. This problem only arises
when I am using the parallel version of the code (i.e. setting -n in
mpiexec to a value greater than 1). Basically if I comment everything
out and then start uncommenting one line at a time, the error appears
once I've uncommented the line with fgets. One strange thing to note
is that the error happens after the program has already finished
executing the function where the problem is. Here's a snippet of the
code that seems to be causing the problem:
PetscErrorCode DataReadParams(SimData *sdata) {
int rank, size;
PetscErrorCode ierr;
int i;
FILE *fd;
char str[256];
char line[100];
int max = 100;
PetscFunctionBegin;
ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size); CHKERRQ(ierr);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank); CHKERRQ(ierr);
/* Read data from files */
sprintf(str,"%s%s",sdata->simname,".param");
ierr = PetscFOpen(PETSC_COMM_WORLD,str,"r",&fd); CHKERRQ(ierr);
if (!rank && !fd) {
SETERRQ1(PETSC_ERR_FILE_OPEN,"Cannot open %s\n",str);
}
// PetscPrintf(PETSC_COMM_WORLD,"Opening file %s\n",str);
fgets(line,max,fd);
sscanf(line,"%d",&sdata->NP);
The error that is kicked out is:
[1]PETSC ERROR: Caught signal number 10 BUS: Bus Error, possibly
illegal memory access
[1]PETSC ERROR: Try option -start_in_debugger or -
on_error_attach_debugger
[1]PETSC ERROR: or try http://valgrind.org on linux to find memory
corruption errors
[1]PETSC ERROR: likely location of problem given in stack below
[1]PETSC ERROR: --------------- Stack Frames ---------------
[1]PETSC ERROR: Note: The EXACT line numbers in the stack are not
available,
[1]PETSC ERROR: INSTEAD the line number of the start of the
function
[1]PETSC ERROR: is given.
[1]PETSC ERROR: [1] DataReadParams line 23 datareadparams.c
[1]PETSC ERROR: [1] SimInit line 19 siminit.c
[1]PETSC ERROR: --------------------------------------------
[1]PETSC ERROR: User provided function() line 0 in unknown directory
unknown file
[1]PETSC ERROR: Signal received!
[1]PETSC ERROR: !
Any insight would be most appreciated.
Josh