* cub::GridQueue is a descriptor utility for dynamic queue management.
*/
#pragma once
#include "../util_namespace.cuh"
#include "../util_debug.cuh"
/// Optional outer namespace(s)
CUB_NS_PREFIX
/// CUB namespace
namespace cub {
/**
* \addtogroup GridModule
* @{
*/
/**
* \brief GridQueue is a descriptor utility for dynamic queue management.
*
* \par Overview
* GridQueue descriptors provides abstractions for "filling" or
* "draining" globally-shared vectors.
*
* \par
* A "filling" GridQueue works by atomically-adding to a zero-initialized counter,
* returning a unique offset for the calling thread to write its items.
* The GridQueue maintains the total "fill-size". The fill counter must be reset
* using GridQueue::ResetFill by the host or kernel instance prior to the kernel instance that
* will be filling.
*
* \par
* Similarly a "draining" GridQueue works by works by atomically-incrementing a
* zero-initialized counter, returning a unique offset for the calling thread to
* read its items. Threads can safely drain until the array's logical fill-size is
* exceeded. The drain counter must be reset using GridQueue::ResetDrain or
* GridQueue::ResetDrainAfterFill by the host or kernel instance prior to the kernel instance that
* will be filling. (For dynamic work distribution of existing data, the corresponding fill-size
* is simply the number of elements in the array.)
*
* \par
* Iterative work management can be implemented simply with a pair of flip-flopping
* work buffers, each with an associated set of fill and drain GridQueue descriptors.
*
* \tparam SizeT Integer type for array indexing
*/
template <typename SizeT>
class GridQueue
{
private:
/// Counter indices
enum
{
FILL = 0,
DRAIN = 1,
};
/// Pair of counters
SizeT *d_counters;
public:
/// Returns the device allocation size in bytes needed to construct a GridQueue instance
__host__ __device__ __forceinline__
static size_t AllocationSize()
{
return sizeof(SizeT) * 2;
}
/// Constructs an invalid GridQueue descriptor around the device storage allocation
__host__ __device__ __forceinline__ GridQueue(
void *d_storage) ///< Device allocation to back the GridQueue. Must be at least as big as <tt>AllocationSize()</tt>.
:
d_counters((SizeT*) d_storage)
{}
/// This operation resets the drain so that it may advance to meet the existing fill-size. To be called by the host or by a kernel prior to that which will be draining.
/// This operation sets the fill-size and resets the drain counter, preparing the GridQueue for draining in the next kernel instance. To be called by the host or by a kernel prior to that which will be draining.