//
// Cforall Version 1.0.0 Copyright (C) 2020 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// io.cfa --
//
// Author           : Thierry Delisle
// Created On       : Thu Apr 23 17:31:00 2020
// Last Modified By :
// Last Modified On :
// Update Count     :
//

#define __cforall_thread__

#if defined(__CFA_DEBUG__)
	// #define __CFA_DEBUG_PRINT_IO__
	// #define __CFA_DEBUG_PRINT_IO_CORE__
#endif


#if defined(CFA_HAVE_LINUX_IO_URING_H)
	#define _GNU_SOURCE         /* See feature_test_macros(7) */
	#include <errno.h>
	#include <signal.h>
	#include <stdint.h>
	#include <string.h>
	#include <unistd.h>

	extern "C" {
		#include <sys/epoll.h>
		#include <sys/eventfd.h>
		#include <sys/syscall.h>

		#include <linux/io_uring.h>
	}

	#include "stats.hfa"
	#include "kernel.hfa"
	#include "kernel/fwd.hfa"
	#include "io/types.hfa"

	static const char * opcodes[] = {
		"OP_NOP",
		"OP_READV",
		"OP_WRITEV",
		"OP_FSYNC",
		"OP_READ_FIXED",
		"OP_WRITE_FIXED",
		"OP_POLL_ADD",
		"OP_POLL_REMOVE",
		"OP_SYNC_FILE_RANGE",
		"OP_SENDMSG",
		"OP_RECVMSG",
		"OP_TIMEOUT",
		"OP_TIMEOUT_REMOVE",
		"OP_ACCEPT",
		"OP_ASYNC_CANCEL",
		"OP_LINK_TIMEOUT",
		"OP_CONNECT",
		"OP_FALLOCATE",
		"OP_OPENAT",
		"OP_CLOSE",
		"OP_FILES_UPDATE",
		"OP_STATX",
		"OP_READ",
		"OP_WRITE",
		"OP_FADVISE",
		"OP_MADVISE",
		"OP_SEND",
		"OP_RECV",
		"OP_OPENAT2",
		"OP_EPOLL_CTL",
		"OP_SPLICE",
		"OP_PROVIDE_BUFFERS",
		"OP_REMOVE_BUFFERS",
		"OP_TEE",
		"INVALID_OP"
	};

	// returns true of acquired as leader or second leader
	static inline bool try_lock( __leaderlock_t & this ) {
		const uintptr_t thrd = 1z | (uintptr_t)active_thread();
		bool block;
		disable_interrupts();
		for() {
			struct $thread * expected = this.value;
			if( 1p != expected && 0p != expected ) {
				/* paranoid */ verify( thrd != (uintptr_t)expected ); // We better not already be the next leader
				enable_interrupts( __cfaabi_dbg_ctx );
				return false;
			}
			struct $thread * desired;
			if( 0p == expected ) {
				// If the lock isn't locked acquire it, no need to block
				desired = 1p;
				block = false;
			}
			else {
				// If the lock is already locked try becomming the next leader
				desired = (struct $thread *)thrd;
				block = true;
			}
			if( __atomic_compare_exchange_n(&this.value, &expected, desired, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ) break;
		}
		if( block ) {
			enable_interrupts( __cfaabi_dbg_ctx );
			park();
			disable_interrupts();
		}
		return true;
	}

	static inline bool next( __leaderlock_t & this ) {
		/* paranoid */ verify( ! __preemption_enabled() );
		struct $thread * nextt;
		for() {
			struct $thread * expected = this.value;
			/* paranoid */ verify( (1 & (uintptr_t)expected) == 1 ); // The lock better be locked

			struct $thread * desired;
			if( 1p == expected ) {
				// No next leader, just unlock
				desired = 0p;
				nextt   = 0p;
			}
			else {
				// There is a next leader, remove but keep locked
				desired = 1p;
				nextt   = (struct $thread *)(~1z & (uintptr_t)expected);
			}
			if( __atomic_compare_exchange_n(&this.value, &expected, desired, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ) break;
		}

		if(nextt) {
			unpark( nextt );
			enable_interrupts( __cfaabi_dbg_ctx );
			return true;
		}
		enable_interrupts( __cfaabi_dbg_ctx );
		return false;
	}

//=============================================================================================
// I/O Syscall
//=============================================================================================
	static int __io_uring_enter( struct __io_data & ring, unsigned to_submit, bool get ) {
		bool need_sys_to_submit = false;
		bool need_sys_to_complete = false;
		unsigned flags = 0;

		TO_SUBMIT:
		if( to_submit > 0 ) {
			if( !(ring.ring_flags & IORING_SETUP_SQPOLL) ) {
				need_sys_to_submit = true;
				break TO_SUBMIT;
			}
			if( (*ring.submit_q.flags) & IORING_SQ_NEED_WAKEUP ) {
				need_sys_to_submit = true;
				flags |= IORING_ENTER_SQ_WAKEUP;
			}
		}

		if( get && !(ring.ring_flags & IORING_SETUP_SQPOLL) ) {
			flags |= IORING_ENTER_GETEVENTS;
			if( (ring.ring_flags & IORING_SETUP_IOPOLL) ) {
				need_sys_to_complete = true;
			}
		}

		int ret = 0;
		if( need_sys_to_submit || need_sys_to_complete ) {
			__cfadbg_print_safe(io_core, "Kernel I/O : IO_URING enter %d %u %u\n", ring.fd, to_submit, flags);
			ret = syscall( __NR_io_uring_enter, ring.fd, to_submit, 0, flags, (sigset_t *)0p, _NSIG / 8);
			if( ret < 0 ) {
				switch((int)errno) {
				case EAGAIN:
				case EINTR:
					ret = -1;
					break;
				default:
					abort( "KERNEL ERROR: IO_URING SYSCALL - (%d) %s\n", (int)errno, strerror(errno) );
				}
			}
		}

		// Memory barrier
		__atomic_thread_fence( __ATOMIC_SEQ_CST );
		return ret;
	}

//=============================================================================================
// I/O Polling
//=============================================================================================
	static unsigned __collect_submitions( struct __io_data & ring );
	static __u32 __release_consumed_submission( struct __io_data & ring );

	// Process a single completion message from the io_uring
	// This is NOT thread-safe
	static inline void process( volatile struct io_uring_cqe & cqe ) {
		struct io_future_t * future = (struct io_future_t *)(uintptr_t)cqe.user_data;
		__cfadbg_print_safe( io, "Kernel I/O : Syscall completed : cqe %p, result %d for %p\n", &cqe, cqe.res, future );

		fulfil( *future, cqe.res );
	}

	static [int, bool] __drain_io( & struct __io_data ring ) {
		/* paranoid */ verify( ! __preemption_enabled() );

		unsigned to_submit = 0;
		if( ring.poller_submits ) {
			// If the poller thread also submits, then we need to aggregate the submissions which are ready
			to_submit = __collect_submitions( ring );
		}

		int ret = __io_uring_enter(ring, to_submit, true);
		if( ret < 0 ) {
			return [0, true];
		}

		// update statistics
		if (to_submit > 0) {
			__STATS__( true,
				if( to_submit > 0 ) {
					io.submit_q.submit_avg.rdy += to_submit;
					io.submit_q.submit_avg.csm += ret;
					io.submit_q.submit_avg.cnt += 1;
				}
			)
		}

		__atomic_thread_fence( __ATOMIC_SEQ_CST );

		// Release the consumed SQEs
		__release_consumed_submission( ring );

		// Drain the queue
		unsigned head = *ring.completion_q.head;
		unsigned tail = *ring.completion_q.tail;
		const __u32 mask = *ring.completion_q.mask;

		// Nothing was new return 0
		if (head == tail) {
			return [0, to_submit > 0];
		}

		__u32 count = tail - head;
		/* paranoid */ verify( count != 0 );
		for(i; count) {
			unsigned idx = (head + i) & mask;
			volatile struct io_uring_cqe & cqe = ring.completion_q.cqes[idx];

			/* paranoid */ verify(&cqe);

			process( cqe );
		}

		// Mark to the kernel that the cqe has been seen
		// Ensure that the kernel only sees the new value of the head index after the CQEs have been read.
		__atomic_fetch_add( ring.completion_q.head, count, __ATOMIC_SEQ_CST );

		return [count, count > 0 || to_submit > 0];
	}

	void main( $io_ctx_thread & this ) {
		epoll_event ev;
		__ioctx_register( this, ev );

		__cfadbg_print_safe(io_core, "Kernel I/O : IO poller %d (%p) ready\n", this.ring->fd, &this);

		const int reset_cnt = 5;
		int reset = reset_cnt;
		// Then loop until we need to start
		LOOP:
		while(!__atomic_load_n(&this.done, __ATOMIC_SEQ_CST)) {
			// Drain the io
			int count;
			bool again;
			disable_interrupts();
				[count, again] = __drain_io( *this.ring );

				if(!again) reset--;

				// Update statistics
				__STATS__( true,
					io.complete_q.completed_avg.val += count;
					io.complete_q.completed_avg.cnt += 1;
				)
			enable_interrupts( __cfaabi_dbg_ctx );

			// If we got something, just yield and check again
			if(reset > 1) {
				yield();
				continue LOOP;
			}

			// We alread failed to find completed entries a few time.
			if(reset == 1) {
				// Rearm the context so it can block
				// but don't block right away
				// we need to retry one last time in case
				// something completed *just now*
				__ioctx_prepare_block( this, ev );
				continue LOOP;
			}

				__STATS__( false,
					io.complete_q.blocks += 1;
				)
				__cfadbg_print_safe(io_core, "Kernel I/O : Parking io poller %d (%p)\n", this.ring->fd, &this);

				// block this thread
				wait( this.sem );

				eventfd_t v;
				eventfd_read(this.ring->efd, &v);

			// restore counter
			reset = reset_cnt;
		}

		__cfadbg_print_safe(io_core, "Kernel I/O : Fast poller %d (%p) stopping\n", this.ring->fd, &this);
	}

//=============================================================================================
// I/O Submissions
//=============================================================================================

// Submition steps :
// 1 - Allocate a queue entry. The ring already has memory for all entries but only the ones
//     listed in sq.array are visible by the kernel. For those not listed, the kernel does not
//     offer any assurance that an entry is not being filled by multiple flags. Therefore, we
//     need to write an allocator that allows allocating concurrently.
//
// 2 - Actually fill the submit entry, this is the only simple and straightforward step.
//
// 3 - Append the entry index to the array and adjust the tail accordingly. This operation
//     needs to arrive to two concensus at the same time:
//     A - The order in which entries are listed in the array: no two threads must pick the
//         same index for their entries
//     B - When can the tail be update for the kernel. EVERY entries in the array between
//         head and tail must be fully filled and shouldn't ever be touched again.
//

	// Allocate an submit queue entry.
	// The kernel cannot see these entries until they are submitted, but other threads must be
	// able to see which entries can be used and which are already un used by an other thread
	// for convenience, return both the index and the pointer to the sqe
	// sqe == &sqes[idx]
	[* volatile struct io_uring_sqe, __u32] __submit_alloc( struct __io_data & ring, __u64 data ) {
		/* paranoid */ verify( data != 0 );

		// Prepare the data we need
		__attribute((unused)) int len   = 0;
		__attribute((unused)) int block = 0;
		__u32 cnt = *ring.submit_q.num;
		__u32 mask = *ring.submit_q.mask;

		__u32 off = thread_rand();

		// Loop around looking for an available spot
		for() {
			// Look through the list starting at some offset
			for(i; cnt) {
				__u64 expected = 3;
				__u32 idx = (i + off) & mask; // Get an index from a random
				volatile struct io_uring_sqe * sqe = &ring.submit_q.sqes[idx];
				volatile __u64 * udata = &sqe->user_data;

				// Allocate the entry by CASing the user_data field from 0 to the future address
				if( *udata == expected &&
					__atomic_compare_exchange_n( udata, &expected, data, true, __ATOMIC_SEQ_CST, __ATOMIC_RELAXED ) )
				{
					// update statistics
					__STATS__( false,
						io.submit_q.alloc_avg.val   += len;
						io.submit_q.alloc_avg.block += block;
						io.submit_q.alloc_avg.cnt   += 1;
					)

					// debug log
					__cfadbg_print_safe( io, "Kernel I/O : allocated [%p, %u] for %p (%p)\n", sqe, idx, active_thread(), (void*)data );

					// Success return the data
					sqe->opcode = 0;
					sqe->flags = 0;
					sqe->ioprio = 0;
					sqe->fd = 0;
					sqe->off = 0;
					sqe->addr = 0;
					sqe->len = 0;
					sqe->accept_flags = 0;
					sqe->__pad2[0] = 0;
					sqe->__pad2[1] = 0;
					sqe->__pad2[2] = 0;
					return [sqe, idx];
				}
				verify(expected != data);

				// This one was used
				len ++;
			}

			block++;

			abort( "Kernel I/O : all submit queue entries used, yielding\n" );

			yield();
		}
	}

	static inline __u32 __submit_to_ready_array( struct __io_data & ring, __u32 idx, const __u32 mask ) {
		/* paranoid */ verify( idx <= mask   );
		/* paranoid */ verify( idx != -1ul32 );

		// We need to find a spot in the ready array
		__attribute((unused)) int len   = 0;
		__attribute((unused)) int block = 0;
		__u32 ready_mask = ring.submit_q.ready_cnt - 1;

		__u32 off = thread_rand();

		__u32 picked;
		LOOKING: for() {
			for(i; ring.submit_q.ready_cnt) {
				picked = (i + off) & ready_mask;
				__u32 expected = -1ul32;
				if( __atomic_compare_exchange_n( &ring.submit_q.ready[picked], &expected, idx, true, __ATOMIC_SEQ_CST, __ATOMIC_RELAXED ) ) {
					break LOOKING;
				}
				verify(expected != idx);

				len ++;
			}

			block++;

			__u32 released = __release_consumed_submission( ring );
			if( released == 0 ) {
				yield();
			}
		}

		// update statistics
		__STATS__( false,
			io.submit_q.look_avg.val   += len;
			io.submit_q.look_avg.block += block;
			io.submit_q.look_avg.cnt   += 1;
		)

		return picked;
	}

	void __submit( struct io_context * ctx, __u32 idx ) __attribute__((nonnull (1))) {
		__io_data & ring = *ctx->thrd.ring;

		{
			__attribute__((unused)) volatile struct io_uring_sqe * sqe = &ring.submit_q.sqes[idx];
			__cfadbg_print_safe( io,
				"Kernel I/O : submitting %u (%p) for %p\n"
				"    data: %p\n"
				"    opcode: %s\n"
				"    fd: %d\n"
				"    flags: %d\n"
				"    prio: %d\n"
				"    off: %p\n"
				"    addr: %p\n"
				"    len: %d\n"
				"    other flags: %d\n"
				"    splice fd: %d\n"
				"    pad[0]: %llu\n"
				"    pad[1]: %llu\n"
				"    pad[2]: %llu\n",
				idx, sqe,
				active_thread(),
				(void*)sqe->user_data,
				opcodes[sqe->opcode],
				sqe->fd,
				sqe->flags,
				sqe->ioprio,
				sqe->off,
				sqe->addr,
				sqe->len,
				sqe->accept_flags,
				sqe->splice_fd_in,
				sqe->__pad2[0],
				sqe->__pad2[1],
				sqe->__pad2[2]
			);
		}


		// Get now the data we definetely need
		volatile __u32 * const tail = ring.submit_q.tail;
		const __u32 mask  = *ring.submit_q.mask;

		// There are 2 submission schemes, check which one we are using
		if( ring.poller_submits ) {
			// If the poller thread submits, then we just need to add this to the ready array
			__submit_to_ready_array( ring, idx, mask );

			post( ctx->thrd.sem );

			__cfadbg_print_safe( io, "Kernel I/O : Added %u to ready for %p\n", idx, active_thread() );
		}
		else if( ring.eager_submits ) {
			__u32 picked = __submit_to_ready_array( ring, idx, mask );

			#if defined(LEADER_LOCK)
				if( !try_lock(ring.submit_q.submit_lock) ) {
					__STATS__( false,
						io.submit_q.helped += 1;
					)
					return;
				}
				/* paranoid */ verify( ! __preemption_enabled() );
				__STATS__( true,
					io.submit_q.leader += 1;
				)
			#else
				for() {
					yield();

					if( try_lock(ring.submit_q.submit_lock __cfaabi_dbg_ctx2) ) {
						__STATS__( false,
							io.submit_q.leader += 1;
						)
						break;
					}

					// If some one else collected our index, we are done
					#warning ABA problem
					if( ring.submit_q.ready[picked] != idx ) {
						__STATS__( false,
							io.submit_q.helped += 1;
						)
						return;
					}

					__STATS__( false,
						io.submit_q.busy += 1;
					)
				}
			#endif

			// We got the lock
			// Collect the submissions
			unsigned to_submit = __collect_submitions( ring );

			// Actually submit
			int ret = __io_uring_enter( ring, to_submit, false );

			#if defined(LEADER_LOCK)
				/* paranoid */ verify( ! __preemption_enabled() );
				next(ring.submit_q.submit_lock);
			#else
				unlock(ring.submit_q.submit_lock);
			#endif
			if( ret < 0 ) {
				return;
			}

			// Release the consumed SQEs
			__release_consumed_submission( ring );

			// update statistics
			__STATS__( false,
				io.submit_q.submit_avg.rdy += to_submit;
				io.submit_q.submit_avg.csm += ret;
				io.submit_q.submit_avg.cnt += 1;
			)

			__cfadbg_print_safe( io, "Kernel I/O : submitted %u (among %u) for %p\n", idx, ret, active_thread() );
		}
		else
		{
			// get mutual exclusion
			#if defined(LEADER_LOCK)
				while(!try_lock(ring.submit_q.submit_lock));
			#else
				lock(ring.submit_q.submit_lock __cfaabi_dbg_ctx2);
			#endif

			/* paranoid */ verifyf( ring.submit_q.sqes[ idx ].user_data != 3ul64,
			/* paranoid */ 	"index %u already reclaimed\n"
			/* paranoid */ 	"head %u, prev %u, tail %u\n"
			/* paranoid */ 	"[-0: %u,-1: %u,-2: %u,-3: %u]\n",
			/* paranoid */ 	idx,
			/* paranoid */ 	*ring.submit_q.head, ring.submit_q.prev_head, *tail
			/* paranoid */ 	,ring.submit_q.array[ ((*ring.submit_q.head) - 0) & (*ring.submit_q.mask) ]
			/* paranoid */ 	,ring.submit_q.array[ ((*ring.submit_q.head) - 1) & (*ring.submit_q.mask) ]
			/* paranoid */ 	,ring.submit_q.array[ ((*ring.submit_q.head) - 2) & (*ring.submit_q.mask) ]
			/* paranoid */ 	,ring.submit_q.array[ ((*ring.submit_q.head) - 3) & (*ring.submit_q.mask) ]
			/* paranoid */ );

			// Append to the list of ready entries

			/* paranoid */ verify( idx <= mask );
			ring.submit_q.array[ (*tail) & mask ] = idx;
			__atomic_fetch_add(tail, 1ul32, __ATOMIC_SEQ_CST);

			// Submit however, many entries need to be submitted
			int ret = __io_uring_enter( ring, 1, false );
			if( ret < 0 ) {
				switch((int)errno) {
				default:
					abort( "KERNEL ERROR: IO_URING SUBMIT - %s\n", strerror(errno) );
				}
			}

			/* paranoid */ verify(ret == 1);

			// update statistics
			__STATS__( false,
				io.submit_q.submit_avg.csm += 1;
				io.submit_q.submit_avg.cnt += 1;
			)

			{
				__attribute__((unused)) volatile __u32 * const head = ring.submit_q.head;
				__attribute__((unused)) __u32 last_idx = ring.submit_q.array[ ((*head) - 1) & mask ];
				__attribute__((unused)) volatile struct io_uring_sqe * sqe = &ring.submit_q.sqes[last_idx];

				__cfadbg_print_safe( io,
					"Kernel I/O : last submitted is %u (%p)\n"
					"    data: %p\n"
					"    opcode: %s\n"
					"    fd: %d\n"
					"    flags: %d\n"
					"    prio: %d\n"
					"    off: %p\n"
					"    addr: %p\n"
					"    len: %d\n"
					"    other flags: %d\n"
					"    splice fd: %d\n"
					"    pad[0]: %llu\n"
					"    pad[1]: %llu\n"
					"    pad[2]: %llu\n",
					last_idx, sqe,
					(void*)sqe->user_data,
					opcodes[sqe->opcode],
					sqe->fd,
					sqe->flags,
					sqe->ioprio,
					sqe->off,
					sqe->addr,
					sqe->len,
					sqe->accept_flags,
					sqe->splice_fd_in,
					sqe->__pad2[0],
					sqe->__pad2[1],
					sqe->__pad2[2]
				);
			}

			__atomic_thread_fence( __ATOMIC_SEQ_CST );
			// Release the consumed SQEs
			__release_consumed_submission( ring );
			// ring.submit_q.sqes[idx].user_data = 3ul64;

			#if defined(LEADER_LOCK)
				next(ring.submit_q.submit_lock);
			#else
				unlock(ring.submit_q.submit_lock);
			#endif

			__cfadbg_print_safe( io, "Kernel I/O : submitted %u for %p\n", idx, active_thread() );
		}
	}

	// #define PARTIAL_SUBMIT 32

	// go through the list of submissions in the ready array and moved them into
	// the ring's submit queue
	static unsigned __collect_submitions( struct __io_data & ring ) {
		/* paranoid */ verify( ring.submit_q.ready != 0p );
		/* paranoid */ verify( ring.submit_q.ready_cnt > 0 );

		unsigned to_submit = 0;
		__u32 tail = *ring.submit_q.tail;
		const __u32 mask = *ring.submit_q.mask;
		#if defined(PARTIAL_SUBMIT)
			#if defined(LEADER_LOCK)
				#error PARTIAL_SUBMIT and LEADER_LOCK cannot co-exist
			#endif
			const __u32 cnt = ring.submit_q.ready_cnt > PARTIAL_SUBMIT ? PARTIAL_SUBMIT : ring.submit_q.ready_cnt;
			const __u32 offset = ring.submit_q.prev_ready;
			ring.submit_q.prev_ready += cnt;
		#else
			const __u32 cnt = ring.submit_q.ready_cnt;
			const __u32 offset = 0;
		#endif

		// Go through the list of ready submissions
		for( c; cnt ) {
			__u32 i = (offset + c) % ring.submit_q.ready_cnt;

			// replace any submission with the sentinel, to consume it.
			__u32 idx = __atomic_exchange_n( &ring.submit_q.ready[i], -1ul32, __ATOMIC_RELAXED);

			// If it was already the sentinel, then we are done
			if( idx == -1ul32 ) continue;

			// If we got a real submission, append it to the list
			ring.submit_q.array[ (tail + to_submit) & mask ] = idx & mask;
			to_submit++;
		}

		// Increment the tail based on how many we are ready to submit
		__atomic_fetch_add(ring.submit_q.tail, to_submit, __ATOMIC_SEQ_CST);

		return to_submit;
	}

	// Go through the ring's submit queue and release everything that has already been consumed
	// by io_uring
	static __u32 __release_consumed_submission( struct __io_data & ring ) {
		const __u32 smask = *ring.submit_q.mask;

		// We need to get the lock to copy the old head and new head
		if( !try_lock(ring.submit_q.release_lock __cfaabi_dbg_ctx2) ) return 0;
		__attribute__((unused))
		__u32 ctail = *ring.submit_q.tail;        // get the current tail of the queue
		__u32 chead = *ring.submit_q.head;		// get the current head of the queue
		__u32 phead = ring.submit_q.prev_head;	// get the head the last time we were here
		ring.submit_q.prev_head = chead;		// note up to were we processed
		unlock(ring.submit_q.release_lock);

		// the 3 fields are organized like this diagram
		// except it's are ring
		// ---+--------+--------+----
		// ---+--------+--------+----
		//    ^        ^        ^
		// phead    chead    ctail

		// make sure ctail doesn't wrap around and reach phead
		/* paranoid */ verify(
			   (ctail >= chead && chead >= phead)
			|| (chead >= phead && phead >= ctail)
			|| (phead >= ctail && ctail >= chead)
		);

		// find the range we need to clear
		__u32 count = chead - phead;

		// We acquired an previous-head/current-head range
		// go through the range and release the sqes
		for( i; count ) {
			__u32 idx = ring.submit_q.array[ (phead + i) & smask ];

			/* paranoid */ verify( 0 != ring.submit_q.sqes[ idx ].user_data );
			ring.submit_q.sqes[ idx ].user_data = 3ul64;
		}
		return count;
	}
#endif