diff --git a/mio/lib/http-fil.c b/mio/lib/http-fil.c
index bec1aa7..a1c4f73 100644
--- a/mio/lib/http-fil.c
+++ b/mio/lib/http-fil.c
@@ -119,6 +119,25 @@ static int file_state_write_to_client (file_state_t* file_state, const void* dat
 	return 0;
 }
 
+static int file_state_sendfile_to_client (file_state_t* file_state, mio_foff_t foff, mio_iolen_t len)
+{
+	file_state->ever_attempted_to_write_to_client = 1;
+
+	file_state->num_pending_writes_to_client++;
+	if (mio_dev_sck_sendfile(file_state->client->sck, file_state->peer, foff, len, MIO_NULL) <= -1) 
+	{
+		file_state->num_pending_writes_to_client--;
+		return -1;
+	}
+
+	if (file_state->num_pending_writes_to_client > FILE_STATE_PENDING_IO_THRESHOLD)
+	{
+		/* STOP READING */
+		/*if (mio_dev_pro_read(file_state->peer, MIO_DEV_PRO_OUT, 0) <= -1) return -1;*/
+	}
+	return 0;
+}
+
 static int file_state_send_final_status_to_client (file_state_t* file_state, int status_code, int force_close)
 {
 	mio_svc_htts_cli_t* cli = file_state->client;
@@ -137,20 +156,6 @@ static int file_state_send_final_status_to_client (file_state_t* file_state, int
 	        (force_close && file_state_write_to_client(file_state, MIO_NULL, 0) <= -1))? -1: 0;
 }
 
-
-#if 0
-static int file_state_write_last_chunk_to_client (file_state_t* file_state)
-{
-	if (!file_state->ever_attempted_to_write_to_client)
-	{
-		if (file_state_send_final_status_to_client(file_state, 500, 0) <= -1) return -1;
-	}
-
-	if (!file_state->keep_alive && file_state_write_to_client(file_state, MIO_NULL, 0) <= -1) return -1;
-	return 0;
-}
-#endif
-
 static void file_state_close_peer (file_state_t* file_state)
 {
 	mio_t* mio = file_state->htts->mio;
@@ -473,7 +478,6 @@ static int file_state_send_contents_to_client (file_state_t* file_state)
  */
 	mio_t* mio = file_state->htts->mio;
 	mio_foff_t lim;
-	ssize_t n;
 
 	if (file_state->cur_offset > file_state->end_offset)
 	{
@@ -483,37 +487,49 @@ static int file_state_send_contents_to_client (file_state_t* file_state)
 	}
 
 	lim = file_state->end_offset - file_state->cur_offset + 1;
-	n = read(file_state->peer, file_state->peer_buf, (lim < MIO_SIZEOF(file_state->peer_buf)? lim: MIO_SIZEOF(file_state->peer_buf)));
-	if (n == -1)
+
+	if (1 /*mio_dev_sck_sendfileok(file_state->client->sck)*/)
 	{
-		if ((errno == EAGAIN || errno == EINTR) && file_state->peer_tmridx == MIO_TMRIDX_INVALID)
+		if (lim > 0xFFFF) lim = 0xFFFF; /* TODO: change this... */
+		if (file_state_sendfile_to_client(file_state, file_state->cur_offset, lim) <= -1) return -1;
+		file_state->cur_offset += lim;
+	}
+	else
+	{
+		ssize_t n;
+
+		n = read(file_state->peer, file_state->peer_buf, (lim < MIO_SIZEOF(file_state->peer_buf)? lim: MIO_SIZEOF(file_state->peer_buf)));
+		if (n == -1)
 		{
-			mio_tmrjob_t tmrjob;
-			/* use a timer job for a new sending attempt */
-			MIO_MEMSET (&tmrjob, 0, MIO_SIZEOF(tmrjob));
-			tmrjob.ctx = file_state;
-			/*tmrjob.when = leave it at 0 for immediate firing.*/
-			tmrjob.handler = send_contents_to_client_later;
-			tmrjob.idxptr = &file_state->peer_tmridx;
-			return mio_instmrjob(mio, &tmrjob) == MIO_TMRIDX_INVALID? -1: 0;
+			if ((errno == EAGAIN || errno == EINTR) && file_state->peer_tmridx == MIO_TMRIDX_INVALID)
+			{
+				mio_tmrjob_t tmrjob;
+				/* use a timer job for a new sending attempt */
+				MIO_MEMSET (&tmrjob, 0, MIO_SIZEOF(tmrjob));
+				tmrjob.ctx = file_state;
+				/*tmrjob.when = leave it at 0 for immediate firing.*/
+				tmrjob.handler = send_contents_to_client_later;
+				tmrjob.idxptr = &file_state->peer_tmridx;
+				return mio_instmrjob(mio, &tmrjob) == MIO_TMRIDX_INVALID? -1: 0;
+			}
+
+			return -1;
+		}
+		else if (n == 0)
+		{
+			/* no more data to read - this must not happend unless file size changed while the file is open. */
+	/* TODO: I probably must close the connection by force??? */
+			file_state_mark_over (file_state, FILE_STATE_OVER_READ_FROM_PEER); 
+			return -1;
 		}
 
-		return -1;
+		if (file_state_write_to_client(file_state, file_state->peer_buf, n) <= -1) return -1;
+
+		file_state->cur_offset += n;
+
+	/*	if (file_state->cur_offset > file_state->end_offset)  should i check this or wait until this function is invoked?
+			file_state_mark_over (file_state, FILE_STATE_OVER_READ_FROM_PEER);*/
 	}
-	else if (n == 0)
-	{
-		/* no more data to read - this must not happend unless file size changed while the file is open. */
-/* TODO: I probably must close the connection by force??? */
-		file_state_mark_over (file_state, FILE_STATE_OVER_READ_FROM_PEER); 
-		return -1;
-	}
-
-	if (file_state_write_to_client(file_state, file_state->peer_buf, n) <= -1) return -1;
-
-	file_state->cur_offset += n;
-
-/*	if (file_state->cur_offset > file_state->end_offset)  should i check this or wait until this function is invoked?
-		file_state_mark_over (file_state, FILE_STATE_OVER_READ_FROM_PEER);*/
 
 	return 0;
 }
diff --git a/mio/lib/mar.c b/mio/lib/mar.c
index 6e9b8c4..cb44872 100644
--- a/mio/lib/mar.c
+++ b/mio/lib/mar.c
@@ -329,6 +329,7 @@ static mio_dev_mth_t dev_mar_methods =
 	MIO_NULL,
 	MIO_NULL,
 	MIO_NULL,
+	MIO_NULL, /* sendfile */
 	dev_mar_ioctl
 };
 
diff --git a/mio/lib/mio-sck.h b/mio/lib/mio-sck.h
index b825012..e5b2bc0 100644
--- a/mio/lib/mio-sck.h
+++ b/mio/lib/mio-sck.h
@@ -475,6 +475,7 @@ MIO_EXPORT int mio_dev_sck_writev (
 	const mio_skad_t*     dstaddr
 );
 
+
 MIO_EXPORT int mio_dev_sck_timedwrite (
 	mio_dev_sck_t*        dev,
 	const void*           data,
@@ -516,13 +517,27 @@ static MIO_INLINE int mio_dev_sck_timedread (mio_dev_sck_t* sck, int enabled, mi
 {
 	return mio_dev_timedread((mio_dev_t*)sck, enabled, tmout);
 }
+
+static MIO_INLINE int mio_dev_sck_sendfile (mio_dev_sck_t* sck, mio_syshnd_t in_fd, mio_foff_t foff, mio_iolen_t len, void* wrctx)
+{
+	return mio_dev_sendfile((mio_dev_t*)sck, in_fd, foff, len, wrctx);
+}
+
+static MIO_INLINE int mio_dev_sck_timedsendfile (mio_dev_sck_t* sck, mio_syshnd_t in_fd, mio_foff_t foff, mio_iolen_t len, mio_ntime_t* tmout, void* wrctx)
+{
+	return mio_dev_timedsendfile((mio_dev_t*)sck, in_fd, foff, len, tmout, wrctx);
+}
+
 #else
 
 #define mio_dev_sck_kill(sck) mio_dev_kill((mio_dev_t*)sck)
 #define mio_dev_sck_halt(sck) mio_dev_halt((mio_dev_t*)sck)
+
 #define mio_dev_sck_read(sck,enabled) mio_dev_read((mio_dev_t*)sck, enabled)
 #define mio_dev_sck_timedread(sck,enabled,tmout) mio_dev_timedread((mio_dev_t*)sck, enabled, tmout)
 
+#define mio_dev_sck_sendfile(sck,in_fd,foff,len,wrctx) mio_dev_sendfile((mio_dev_t*)sck, in_fd, foff, len, wrctx)
+#define mio_dev_sck_timedsendfile(sck,in_fd,foff,len,tmout,wrctx) mio_dev_timedsendfile((mio_dev_t*)sck, in_fd, foff, len, tmout, wrctx)
 #endif
 
 
diff --git a/mio/lib/mio.c b/mio/lib/mio.c
index ba46258..f1e3f77 100644
--- a/mio/lib/mio.c
+++ b/mio/lib/mio.c
@@ -37,6 +37,13 @@ static int kill_and_free_device (mio_dev_t* dev, int force);
 static void on_read_timeout (mio_t* mio, const mio_ntime_t* now, mio_tmrjob_t* job);
 static void on_write_timeout (mio_t* mio, const mio_ntime_t* now, mio_tmrjob_t* job);
 
+struct wq_sendfile_data_t
+{
+	mio_syshnd_t in_fd;
+	mio_foff_t foff;
+};
+typedef struct wq_sendfile_data_t wq_sendfile_data_t;
+
 /* ========================================================================= */
 
 static void* mmgr_alloc (mio_mmgr_t* mmgr, mio_oow_t size)
@@ -444,7 +451,14 @@ static MIO_INLINE void handle_event (mio_t* mio, mio_dev_t* dev, int events, int
 
 		send_leftover:
 			ulen = urem;
-			x = dev->dev_mth->write(dev, uptr, &ulen, &q->dstaddr);
+			if (q->sendfile)
+			{
+				x = dev->dev_mth->sendfile(dev, ((wq_sendfile_data_t*)uptr)->in_fd, ((wq_sendfile_data_t*)uptr)->foff, &ulen);
+			}
+			else
+			{
+				x = dev->dev_mth->write(dev, uptr, &ulen, &q->dstaddr);
+			}
 			if (x <= -1)
 			{
 				mio_dev_halt (dev);
@@ -1291,6 +1305,7 @@ static MIO_INLINE int __enqueue_pending_write (mio_dev_t* dev, mio_iolen_t olen,
 	q = (mio_wq_t*)mio_allocmem(mio, MIO_SIZEOF(*q) + (dstaddr? dstaddr->len: 0) + urem);
 	if (MIO_UNLIKELY(!q)) return -1;
 
+	q->sendfile = 0;
 	q->tmridx = MIO_TMRIDX_INVALID;
 	q->dev = dev;
 	q->ctx = wrctx;
@@ -1349,7 +1364,81 @@ static MIO_INLINE int __enqueue_pending_write (mio_dev_t* dev, mio_iolen_t olen,
 	return 0; /* request pused to a write queue. */
 }
 
-static int __dev_write (mio_dev_t* dev, const void* data, mio_iolen_t len, const mio_ntime_t* tmout, void* wrctx, const mio_devaddr_t* dstaddr)
+static MIO_INLINE int __enqueue_pending_sendfile (mio_dev_t* dev, mio_iolen_t olen, mio_iolen_t urem, mio_foff_t foff, mio_syshnd_t in_fd, const mio_ntime_t* tmout, void* wrctx, const mio_devaddr_t* dstaddr)
+{
+	mio_t* mio = dev->mio;
+	mio_wq_t* q;
+
+	if (dev->dev_cap & MIO_DEV_CAP_OUT_UNQUEUEABLE)
+	{
+		/* writing queuing is not requested. so return failure */
+		mio_seterrbfmt (mio, MIO_ENOCAPA, "device incapable of queuing");
+		return -1;
+	}
+
+	/* queue the remaining data*/
+	q = (mio_wq_t*)mio_allocmem(mio, MIO_SIZEOF(*q) + (dstaddr? dstaddr->len: 0) + MIO_SIZEOF(wq_sendfile_data_t));
+	if (MIO_UNLIKELY(!q)) return -1;
+
+	q->sendfile = 1;
+	q->tmridx = MIO_TMRIDX_INVALID;
+	q->dev = dev;
+	q->ctx = wrctx;
+
+	if (dstaddr)
+	{
+		q->dstaddr.ptr = (mio_uint8_t*)(q + 1);
+		q->dstaddr.len = dstaddr->len;
+		MIO_MEMCPY (q->dstaddr.ptr, dstaddr->ptr, dstaddr->len);
+	}
+	else
+	{
+		q->dstaddr.len = 0;
+	}
+
+	q->ptr = (mio_uint8_t*)(q + 1) + q->dstaddr.len;
+	q->len = urem;
+	q->olen = olen; /* original length to use when invoking on_write() */
+
+	((wq_sendfile_data_t*)q->ptr)->in_fd = in_fd;
+	((wq_sendfile_data_t*)q->ptr)->foff = foff;
+
+	if (tmout && MIO_IS_POS_NTIME(tmout))
+	{
+		mio_tmrjob_t tmrjob;
+
+		MIO_MEMSET (&tmrjob, 0, MIO_SIZEOF(tmrjob));
+		tmrjob.ctx = q;
+		mio_gettime (mio, &tmrjob.when);
+		MIO_ADD_NTIME (&tmrjob.when, &tmrjob.when, tmout);
+		tmrjob.handler = on_write_timeout;
+		tmrjob.idxptr = &q->tmridx;
+
+		q->tmridx = mio_instmrjob(mio, &tmrjob);
+		if (q->tmridx == MIO_TMRIDX_INVALID) 
+		{
+			mio_freemem (mio, q);
+			return -1;
+		}
+	}
+
+	MIO_WQ_ENQ (&dev->wq, q);
+	if (!(dev->dev_cap & MIO_DEV_CAP_OUT_WATCHED))
+	{
+		/* if output is not being watched, arrange to do so */
+		if (mio_dev_watch(dev, MIO_DEV_WATCH_RENEW, MIO_DEV_EVENT_IN) <= -1)
+		{
+			unlink_wq (mio, q);
+			mio_freemem (mio, q);
+			return -1;
+		}
+	}
+
+	return 0; /* request pused to a write queue. */
+}
+
+
+static MIO_INLINE int __dev_write (mio_dev_t* dev, const void* data, mio_iolen_t len, const mio_ntime_t* tmout, void* wrctx, const mio_devaddr_t* dstaddr)
 {
 	mio_t* mio = dev->mio;
 	const mio_uint8_t* uptr;
@@ -1444,7 +1533,7 @@ enqueue_completed_write:
 	return __enqueue_completed_write(dev, len, wrctx, dstaddr);
 }
 
-static int __dev_writev (mio_dev_t* dev, mio_iovec_t* iov, mio_iolen_t iovcnt, const mio_ntime_t* tmout, void* wrctx, const mio_devaddr_t* dstaddr)
+static MIO_INLINE int __dev_writev (mio_dev_t* dev, mio_iovec_t* iov, mio_iolen_t iovcnt, const mio_ntime_t* tmout, void* wrctx, const mio_devaddr_t* dstaddr)
 {
 	mio_t* mio = dev->mio;
 	mio_iolen_t urem, len;
@@ -1551,18 +1640,23 @@ enqueue_completed_write:
 
 static int __dev_sendfile (mio_dev_t* dev, mio_syshnd_t in_fd, mio_foff_t foff, mio_iolen_t len, const mio_ntime_t* tmout, void* wrctx)
 {
-#if 1
 	mio_t* mio = dev->mio;
 	mio_foff_t uoff;
 	mio_iolen_t urem, ulen;
 	int x;
 
-	if (dev->dev_cap & MIO_DEV_CAP_OUT_CLOSED)
+	if (MIO_UNLIKELY(dev->dev_cap & MIO_DEV_CAP_OUT_CLOSED))
 	{
 		mio_seterrbfmt (mio, MIO_ENOCAPA, "unable to sendfile to closed device");
 		return -1;
 	}
 
+	if (MIO_UNLIKELY(!dev->dev_mth->sendfile))
+	{
+		mio_seterrbfmt (mio, MIO_ENOCAPA, "unable to senfile over unsupported device");
+		return -1;
+	}
+
 	uoff = foff;
 	urem = len;
 
@@ -1579,7 +1673,7 @@ static int __dev_sendfile (mio_dev_t* dev, mio_syshnd_t in_fd, mio_foff_t foff,
 		do
 		{
 			ulen = urem;
-			x = dev->dev_mth->sendfile(dev, in_fd, foff, &ulen);
+			x = dev->dev_mth->sendfile(dev, in_fd, uoff, &ulen);
 			if (x <= -1) return -1;
 			else if (x == 0) 
 			{
@@ -1626,21 +1720,11 @@ static int __dev_sendfile (mio_dev_t* dev, mio_syshnd_t in_fd, mio_foff_t foff,
 	return 1; /* written immediately and called on_write callback. but this line will never be reached */
 
 enqueue_data:
-#if 0
-	iov.iov_ptr = (void*)uptr;
-	iov.iov_len = urem;
-	return __enqueue_pending_write(dev, len, urem, &iov, 1, 0, tmout, wrctx, dstaddr);
-#else
-	/* TODO: */
-	return -1;
-#endif
-
+printf ("queueing sendfiel...\n");
+	return __enqueue_pending_sendfile(dev, len, urem, uoff, in_fd, tmout, wrctx, MIO_NULL);
 
 enqueue_completed_write:
-	return __enqueue_completed_write(dev, len, wrctx, dstaddr);
-#else
-	return 0;
-#endif
+	return __enqueue_completed_write(dev, len, wrctx, MIO_NULL);
 }
 
 int mio_dev_write (mio_dev_t* dev, const void* data, mio_iolen_t len, void* wrctx, const mio_devaddr_t* dstaddr)
@@ -1653,6 +1737,11 @@ int mio_dev_writev (mio_dev_t* dev, mio_iovec_t* iov, mio_iolen_t iovcnt, void*
 	return __dev_writev(dev, iov, iovcnt, MIO_NULL, wrctx, dstaddr);
 }
 
+int mio_dev_sendfile (mio_dev_t* dev, mio_syshnd_t in_fd, mio_foff_t foff, mio_iolen_t len, void* wrctx)
+{
+	return __dev_sendfile(dev,in_fd, foff, len, MIO_NULL, wrctx);
+}
+
 int mio_dev_timedwrite (mio_dev_t* dev, const void* data, mio_iolen_t len, const mio_ntime_t* tmout, void* wrctx, const mio_devaddr_t* dstaddr)
 {
 	return __dev_write(dev, data, len, tmout, wrctx, dstaddr);
@@ -1663,6 +1752,11 @@ int mio_dev_timedwritev (mio_dev_t* dev, mio_iovec_t* iov, mio_iolen_t iovcnt, c
 	return __dev_writev(dev, iov, iovcnt, tmout, wrctx, dstaddr);
 }
 
+int mio_dev_timedsendfile (mio_dev_t* dev, mio_syshnd_t in_fd, mio_foff_t foff, mio_iolen_t len, const mio_ntime_t* tmout, void* wrctx)
+{
+	return __dev_sendfile(dev,in_fd, foff, len, tmout, wrctx);
+}
+
 /* -------------------------------------------------------------------------- */
 
 void mio_gettime (mio_t* mio, mio_ntime_t* now)
diff --git a/mio/lib/mio.h b/mio/lib/mio.h
index 27b37a2..a80d149 100644
--- a/mio/lib/mio.h
+++ b/mio/lib/mio.h
@@ -299,6 +299,7 @@ struct mio_wq_t
 	mio_wq_t*       q_next;
 	mio_wq_t*       q_prev;
 
+	int             sendfile;
 	mio_iolen_t     olen; /* original data length */
 	mio_uint8_t*    ptr;  /* pointer to data */
 	mio_iolen_t     len;  /* remaining data length */
@@ -899,6 +900,14 @@ MIO_EXPORT int mio_dev_writev (
 	const mio_devaddr_t*  dstaddr
 );
 
+MIO_EXPORT int mio_dev_sendfile (
+	mio_dev_t*            dev,
+	mio_syshnd_t          in_fd,
+	mio_foff_t            foff,
+	mio_iolen_t           len,
+	void*                 wrctx
+);
+
 MIO_EXPORT int mio_dev_timedwrite (
 	mio_dev_t*           dev,
 	const void*          data,
@@ -918,6 +927,14 @@ MIO_EXPORT int mio_dev_timedwritev (
 	const mio_devaddr_t*  dstaddr
 );
 
+MIO_EXPORT int mio_dev_timedsendfile (
+	mio_dev_t*            dev,
+	mio_syshnd_t          in_fd,
+	mio_foff_t            foff,
+	mio_iolen_t           len,
+	const mio_ntime_t*    tmout,
+	void*                 wrctx
+);
 /* =========================================================================
  * SERVICE 
  * ========================================================================= */
diff --git a/mio/lib/pro.c b/mio/lib/pro.c
index 1a22f70..0b0337d 100644
--- a/mio/lib/pro.c
+++ b/mio/lib/pro.c
@@ -732,9 +732,10 @@ static mio_dev_mth_t dev_pro_methods =
 	dev_pro_kill_master,
 	dev_pro_getsyshnd,
 
-	MIO_NULL,
-	MIO_NULL,
-	MIO_NULL,
+	MIO_NULL, /* read */
+	MIO_NULL, /* write */
+	MIO_NULL, /* writev */
+	MIO_NULL, /* sendfile */
 	dev_pro_ioctl
 };
 
@@ -747,6 +748,7 @@ static mio_dev_mth_t dev_pro_methods_slave =
 	dev_pro_read_slave,
 	dev_pro_write_slave,
 	dev_pro_writev_slave,
+	MIO_NULL, /* sendfile */
 	dev_pro_ioctl
 };
 
diff --git a/mio/lib/sck.c b/mio/lib/sck.c
index 2c99e96..29f7738 100644
--- a/mio/lib/sck.c
+++ b/mio/lib/sck.c
@@ -44,6 +44,9 @@
 #	include <net/if_dl.h>
 #endif
 
+#if defined(HAVE_SYS_SENDFILE_H)
+#	include <sys/sendfile.h>
+#endif
 
 #if defined(__linux__)
 #	include <limits.h>
@@ -409,6 +412,7 @@ static mio_syshnd_t dev_sck_getsyshnd (mio_dev_t* dev)
 	mio_dev_sck_t* rdev = (mio_dev_sck_t*)dev;
 	return (mio_syshnd_t)rdev->hnd;
 }
+/* ------------------------------------------------------------------------------ */
 
 static int dev_sck_read_stateful (mio_dev_t* dev, void* buf, mio_iolen_t* len, mio_devaddr_t* srcaddr)
 {
@@ -476,6 +480,7 @@ static int dev_sck_read_stateless (mio_dev_t* dev, void* buf, mio_iolen_t* len,
 	return 1;
 }
 
+/* ------------------------------------------------------------------------------ */
 
 static int dev_sck_write_stateful (mio_dev_t* dev, const void* data, mio_iolen_t* len, const mio_devaddr_t* dstaddr)
 {
@@ -643,6 +648,8 @@ static int dev_sck_writev_stateful (mio_dev_t* dev, const mio_iovec_t* iov, mio_
 	return 1;
 }
 
+/* ------------------------------------------------------------------------------ */
+
 static int dev_sck_write_stateless (mio_dev_t* dev, const void* data, mio_iolen_t* len, const mio_devaddr_t* dstaddr)
 {
 	mio_t* mio = dev->mio;
@@ -691,6 +698,88 @@ static int dev_sck_writev_stateless (mio_dev_t* dev, const mio_iovec_t* iov, mio
 	return 1;
 }
 
+/* ------------------------------------------------------------------------------ */
+
+static int dev_sck_sendfile_stateful (mio_dev_t* dev, mio_syshnd_t in_fd, mio_foff_t foff, mio_iolen_t* len)
+{
+	mio_t* mio = dev->mio;
+	mio_dev_sck_t* rdev = (mio_dev_sck_t*)dev;
+
+#if 0 && defined(USE_SSL)
+/* TODO: ssl needs to read from the file... and send... */
+	if (rdev->ssl)
+	{
+		int x;
+
+		if (*len <= 0)
+		{
+			/* it's a writing finish indicator. close the writing end of
+			 * the socket, probably leaving it in the half-closed state */
+			if ((x = SSL_shutdown((SSL*)rdev->ssl)) == -1)
+			{
+				set_ssl_error (mio, SSL_get_error((SSL*)rdev->ssl, x));
+				return -1;
+			}
+			return 1;
+		}
+
+		x = SSL_write((SSL*)rdev->ssl, data, *len);
+		if (x <= -1)
+		{
+			int err = SSL_get_error ((SSL*)rdev->ssl, x);
+			if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE) return 0;
+			set_ssl_error (mio, err);
+			return -1;
+		}
+
+		*len = x;
+	}
+	else
+	{
+#endif
+		ssize_t x;
+
+		if (*len <= 0)
+		{
+			/* the write handler for a stream device must handle a zero-length 
+			 * writing request specially. it's a writing finish indicator. close
+			 * the writing end of the socket, probably leaving it in the half-closed state */
+			if (shutdown(rdev->hnd, SHUT_WR) == -1)
+			{
+				mio_seterrwithsyserr (mio, 0, errno);
+				return -1;
+			}
+
+			/* it must return a non-zero positive value. if it returns 0, this request 
+			 * gets enqueued by the core. we must aovid it */
+			return 1;
+		}
+
+#if defined(HAVE_SENDFILE)
+/* TODO: cater for other systems */
+		x = sendfile(rdev->hnd, in_fd, &foff, *len);
+		if (x == -1) 
+		{
+			if (errno == EINPROGRESS || errno == EWOULDBLOCK || errno == EAGAIN) return 0;  /* no data can be written */
+			if (errno == EINTR) return 0;
+			mio_seterrwithsyserr (mio, 0, errno);
+			return -1;
+		}
+		*len = x;
+#else
+		mio_seterrnum (mio, MIO_ENOIMPL);
+		return -1;
+#endif
+
+	
+#if 0 && defined(USE_SSL)
+	}
+#endif
+	return 1;
+}
+
+/* ------------------------------------------------------------------------------ */
+
 #if defined(USE_SSL)
 
 static int do_ssl (mio_dev_sck_t* dev, int (*ssl_func)(SSL*))
@@ -1124,6 +1213,7 @@ static mio_dev_mth_t dev_sck_methods_stateless =
 	dev_sck_read_stateless,
 	dev_sck_write_stateless,
 	dev_sck_writev_stateless,
+	MIO_NULL,          /* sendfile */
 	dev_sck_ioctl,     /* ioctl */
 };
 
@@ -1137,6 +1227,7 @@ static mio_dev_mth_t dev_sck_methods_stateful =
 	dev_sck_read_stateful,
 	dev_sck_write_stateful,
 	dev_sck_writev_stateful,
+	dev_sck_sendfile_stateful,
 	dev_sck_ioctl,     /* ioctl */
 };
 
@@ -1149,6 +1240,7 @@ static mio_dev_mth_t dev_mth_clisck =
 	dev_sck_read_stateful,
 	dev_sck_write_stateful,
 	dev_sck_writev_stateful,
+	dev_sck_sendfile_stateful,
 	dev_sck_ioctl
 };
 /* ========================================================================= */
@@ -1710,7 +1802,6 @@ int mio_dev_sck_timedwritev (mio_dev_sck_t* dev, mio_iovec_t* iov, mio_iolen_t i
 	return mio_dev_timedwritev((mio_dev_t*)dev, iov, iovcnt, tmout, wrctx, skad_to_devaddr(dev, dstaddr, &devaddr));
 }
 
-
 /* ========================================================================= */
 int mio_dev_sck_setsockopt (mio_dev_sck_t* dev, int level, int optname, void* optval, mio_scklen_t optlen)
 {