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Documentation: shmem_array_start_writing documentation #1724

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f8ac1d2
Improve documentation of shmem_array_start_writing
Davknapp Jun 30, 2025
3eb1d7c
fix line endings
Davknapp Jun 30, 2025
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26 changes: 14 additions & 12 deletions src/t8_data/t8_shmem.h
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Original file line number Diff line number Diff line change
Expand Up @@ -100,6 +100,8 @@ t8_shmem_array_init (t8_shmem_array_t *parray, size_t elem_size, size_t elem_cou

/** Enable writing mode for a shmem array. Only some processes may be allowed
* to write into the array, which is indicated by the return value being non-zero.
* The shared memory is managed via inter- and intranode communicators.
* Only rank 0 of the intranode communicator will be allowed to write into the array.
* \param [in,out] array Initialized array. Writing will be enabled on certain processes.
* \return True if the calling process can write into the array.
* \note This function is MPI collective.
Expand Down Expand Up @@ -152,31 +154,31 @@ t8_shmem_array_allgather (const void *sendbuf, int sendcount, sc_MPI_Datatype se
* Computes the recvcount-array and displacement-array for each rank of a node using the
* sendcount.
* The total number of items of each node is then used to compute the
* recvcount-array and displacement-array between nodes.
* Use t8_shmem_array_allgather if the sendcount is equal on all procs for better scaling.
*
* recvcount-array and displacement-array between nodes.
* Use t8_shmem_array_allgather if the sendcount is equal on all procs for better scaling.
*
* \param[in] sendbuf the source from this process
* \param[in] sendcount the number of items to gather on this proc
* \param[in] sendtype the type of items to gather
* \param[in, out] recvarray array of type recvtype where the data gets written to
* \param[in] recvtype the type of items to receive
* \param[in] comm the mpi communicator
*
*
*/
void
t8_shmem_array_allgatherv (void *sendbuf, const int sendcount, sc_MPI_Datatype sendtype, t8_shmem_array_t recvarray,
sc_MPI_Datatype recvtype, sc_MPI_Comm comm);

/**
* Fill a t8_shmem array with an Allgather of the prefix operation over all
* processes.
*
* Fill a t8_shmem array with an Allgather of the prefix operation over all
* processes.
*
* The receive array will be
* (0, send0, send0 op send1, send0 op send1 op send2, ...)
*
* \note the first entry of \a recvarray will be set to 0 using memset.
* The entry can be changed after calling t8_shmem_array_prefix
*
*
* \note the first entry of \a recvarray will be set to 0 using memset.
* The entry can be changed after calling t8_shmem_array_prefix
*
* \param[in] sendbuf The source from this process
* \param[in, out] recvarray The destination shmem array
* \param[in] count The number of items to gather
Expand Down Expand Up @@ -265,7 +267,7 @@ void *
t8_shmem_array_index_for_writing (t8_shmem_array_t array, size_t index);

/* TODO: implement and comment */
/* returns true if arrays are equal
/* returns true if arrays are equal
* \note Writing mode must be disabled for \a array_a and \a array_b.
*/
int
Expand Down