/* A comparision function between two handles makes it possible to use qsort to
* sort a list of handles */
static int _starpu_compar_handles(const struct _starpu_data_descr *descrA,
const struct _starpu_data_descr *descrB)
{
struct _starpu_data_state *dataA = descrA->handle;
struct _starpu_data_state *dataB = descrB->handle;
/* Perhaps we have the same piece of data */
if (dataA == dataB)
{
/* Process write requests first, this is needed for proper
* locking, see _submit_job_enforce_data_deps,
* _starpu_fetch_task_input, and _starpu_push_task_output */
if (descrA->mode & STARPU_W)
{
if (descrB->mode & STARPU_W)
/* Both A and B write, take the reader first */
if (descrA->mode & STARPU_R)
return -1;
else
return 1;
else
/* Only A writes, take it first */
return -1;
}
else
/* A doesn't write, take B before */
return 1;
}
/* Put arbitered accesses after non-arbitered */
if (dataA->arbiter && !(dataB->arbiter))
return 1;
if (dataB->arbiter && !(dataA->arbiter))
return -1;
if (dataA->arbiter != dataB->arbiter)
/* Both are arbitered, sort by arbiter pointer order */
return ((dataA->arbiter < dataB->arbiter)?-1:1);
/* If both are arbitered by the same arbiter (or they are both not
* arbitered), we'll sort them by handle */
/* In case we have data/subdata from different trees */
if (dataA->root_handle != dataB->root_handle)
return ((dataA->root_handle < dataB->root_handle)?-1:1);
/* Things get more complicated: we need to find the location of dataA
* and dataB within the tree. */
unsigned dataA_path[dataA->depth - 1];
unsigned dataB_path[dataB->depth - 1];
find_data_path(dataA, dataA_path);
find_data_path(dataB, dataB_path);
return _compar_data_paths(dataA_path, dataA->depth, dataB_path, dataB->depth);
}
/* A comparision function between two handles makes it possible to use qsort to
* sort a list of handles */
static int _starpu_compar_handles(struct starpu_data_state_t *dataA,
struct starpu_data_state_t *dataB)
{
/* Perhaps we have the same piece of data */
if (dataA == dataB)
return 0;
/* In case we have data/subdata from different trees */
if (dataA->root_handle != dataB->root_handle)
return ((dataA->root_handle < dataB->root_handle)?-1:1);
/* Things get more complicated: we need to find the location of dataA
* and dataB within the tree. */
unsigned dataA_path[dataA->depth - 1];
unsigned dataB_path[dataB->depth - 1];
find_data_path(dataA, dataA_path);
find_data_path(dataB, dataB_path);
return _compar_data_paths(dataA_path, dataA->depth, dataB_path, dataB->depth);
}
