:orphan:
# PetscBarrier
Blocks until this routine is executed by all processors owning the object `obj`. 
## Synopsis
```
#include "petscsys.h" 
PetscErrorCode PetscBarrier(PetscObject obj)
```

## Input Parameter

- ***obj -*** PETSc object  (`Mat`, `Vec`, `IS`, `SNES` etc...)
The object must be cast with a (`PetscObject`). `NULL` can be used to indicate the barrier should be across `PETSC_COMM_WORLD`





## Developer Note
This routine calls `MPI_Barrier()` with the communicator of the `PetscObject`


## Fortran Note
You may pass `PETSC_NULL_VEC` or any other PETSc null object, such as `PETSC_NULL_MAT`, to indicate the barrier should be
across `PETSC_COMM_WORLD`. You can also pass in any PETSc object, `Vec`, `Mat`, etc


## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/utils/pbarrier.c.html#PetscBarrier">src/sys/utils/pbarrier.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/dm/tutorials/ex22.c.html">src/dm/tutorials/ex22.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex63.c.html">src/snes/tutorials/ex63.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/elliptic.c.html">src/tao/pde_constrained/tutorials/elliptic.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/hyperbolic.c.html">src/tao/pde_constrained/tutorials/hyperbolic.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/parabolic.c.html">src/tao/pde_constrained/tutorials/parabolic.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/vec/tutorials/performance.c.html">src/vec/vec/tutorials/performance.c</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/utils/pbarrier.c)


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