src/stream_interface.c - haproxy - Gitiles

 /*
  * Functions managing stream_interface structures
  *
  * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  *
  */

 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>

 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>

 #include <common/compat.h>
 #include <common/config.h>
 #include <common/debug.h>
 #include <common/standard.h>
 #include <common/ticks.h>
 #include <common/time.h>

 #include <proto/buffers.h>
 #include <proto/fd.h>
 #include <proto/stream_interface.h>
 #include <proto/stream_sock.h>
 #include <proto/task.h>

 /*
  * This function only has to be called once after a wakeup event in case of
  * suspected timeout. It controls the stream interface timeouts and sets
  * si->flags accordingly. It does NOT close anything, as this timeout may
  * be used for any purpose. It returns 1 if the timeout fired, otherwise
  * zero.
  */
 int stream_int_check_timeouts(struct stream_interface *si)
 {
 	if (tick_is_expired(si->exp, now_ms)) {
 		si->flags |= SI_FL_EXP;
 		return 1;
 	}
 	return 0;
 }

 /* to be called only when in SI_ST_DIS with SI_FL_ERR */
 void stream_int_report_error(struct stream_interface *si)
 {
 	if (!si->err_type)
 		si->err_type = SI_ET_DATA_ERR;

 	si->ob->flags |= BF_WRITE_ERROR;
 	si->ib->flags |= BF_READ_ERROR;
 }

 /*
  * Returns a message to the client ; the connection is shut down for read,
  * and the request is cleared so that no server connection can be initiated.
  * The buffer is marked for read shutdown on the other side to protect the
  * message, and the buffer write is enabled. The message is contained in a
  * "chunk". If it is null, then an empty message is used. The reply buffer does
  * not need to be empty before this, and its contents will not be overwritten.
  * The primary goal of this function is to return error messages to a client.
  */
 void stream_int_retnclose(struct stream_interface *si, const struct chunk *msg)
 {
 	buffer_auto_read(si->ib);
 	buffer_abort(si->ib);
 	buffer_auto_close(si->ib);
 	buffer_erase(si->ib);
 	if (likely(msg && msg->len))
 		buffer_write(si->ob, msg->str, msg->len);

 	si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
 	buffer_auto_read(si->ob);
 	buffer_auto_close(si->ob);
 	buffer_shutr_now(si->ob);
 }

 /* default update function for scheduled tasks, not used for embedded tasks */
 void stream_int_update(struct stream_interface *si)
 {
 	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
 		__FUNCTION__,
 		si, si->state, si->ib->flags, si->ob->flags);

 	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
 		task_wakeup(si->owner, TASK_WOKEN_IO);
 }

 /* default update function for embedded tasks, to be used at the end of the i/o handler */
 void stream_int_update_embedded(struct stream_interface *si)
 {
 	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
 		__FUNCTION__,
 		si, si->state, si->ib->flags, si->ob->flags);

 	if (si->state != SI_ST_EST)
 		return;

 	if ((si->ob->flags & (BF_OUT_EMPTY|BF_SHUTW|BF_HIJACK|BF_SHUTW_NOW)) == (BF_OUT_EMPTY|BF_SHUTW_NOW))
 		si->shutw(si);

 	if ((si->ob->flags & (BF_FULL|BF_SHUTW|BF_SHUTW_NOW|BF_HIJACK)) == 0)
 		si->flags |= SI_FL_WAIT_DATA;

 	/* we're almost sure that we need some space if the buffer is not
 	 * empty, even if it's not full, because the applets can't fill it.
 	 */
 	if ((si->ib->flags & (BF_SHUTR|BF_OUT_EMPTY|BF_DONT_READ)) == 0)
 		si->flags |= SI_FL_WAIT_ROOM;

 	if (si->ob->flags & BF_WRITE_ACTIVITY) {
 		if (tick_isset(si->ob->wex))
 			si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
 	}

 	if (si->ib->flags & BF_READ_ACTIVITY ||
 	    (si->ob->flags & BF_WRITE_ACTIVITY && !(si->flags & SI_FL_INDEP_STR))) {
 		if (tick_isset(si->ib->rex))
 			si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
 	}

 	if (likely((si->ob->flags & (BF_SHUTW|BF_WRITE_PARTIAL|BF_FULL|BF_DONT_READ)) == BF_WRITE_PARTIAL &&
 		   (si->ob->prod->flags & SI_FL_WAIT_ROOM)))
 		si->ob->prod->chk_rcv(si->ob->prod);

 	if (((si->ib->flags & (BF_READ_PARTIAL|BF_OUT_EMPTY)) == BF_READ_PARTIAL) &&
 	    (si->ib->cons->flags & SI_FL_WAIT_DATA))
 		si->ib->cons->chk_snd(si->ib->cons);

 	/* Note that we're trying to wake up in two conditions here :
 	 *  - special event, which needs the holder task attention
 	 *  - status indicating that the applet can go on working. This
 	 *    is rather hard because we might be blocking on output and
 	 *    don't want to wake up on input and vice-versa. The idea is
 	 *    the to only rely the changes the chk_* might have performed.
 	 */
 	if (/* check stream interface changes */
 	    (si->flags & SI_FL_ERR) || si->state != SI_ST_EST || si->ib->cons->state != SI_ST_EST ||
 	    /* check response buffer changes */
 	    (si->ib->flags & (BF_READ_NULL|BF_READ_ERROR|BF_READ_DONTWAIT)) ||
 	    ((si->ib->flags & BF_READ_ACTIVITY) && !si->ib->to_forward) ||
 	    (!(si->ib->flags & BF_FULL) && (si->ib->flags & BF_WRITE_ACTIVITY) && si->ib->to_forward) ||
 	    /* check request buffer changes */
 	    (si->ob->flags & (BF_WRITE_ERROR)) ||
 	    ((si->ob->flags & BF_WRITE_ACTIVITY) && (si->ob->flags & BF_OUT_EMPTY) && !si->ob->to_forward) ||
 	    (si->ob->flags & BF_READ_ACTIVITY)) {
 		if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
 			task_wakeup(si->owner, TASK_WOKEN_IO);
 	}
 }

 /* default shutr function for scheduled tasks */
 void stream_int_shutr(struct stream_interface *si)
 {
 	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
 		__FUNCTION__,
 		si, si->state, si->ib->flags, si->ob->flags);

 	si->ib->flags &= ~BF_SHUTR_NOW;
 	if (si->ib->flags & BF_SHUTR)
 		return;
 	si->ib->flags |= BF_SHUTR;
 	si->ib->rex = TICK_ETERNITY;
 	si->flags &= ~SI_FL_WAIT_ROOM;

 	if (si->state != SI_ST_EST && si->state != SI_ST_CON)
 		return;

 	if (si->ob->flags & BF_SHUTW) {
 		si->state = SI_ST_DIS;
 		si->exp = TICK_ETERNITY;
 	}

 	/* note that if the task exist, it must unregister itself once it runs */
 	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
 		task_wakeup(si->owner, TASK_WOKEN_IO);
 }

 /* default shutw function for scheduled tasks */
 void stream_int_shutw(struct stream_interface *si)
 {
 	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
 		__FUNCTION__,
 		si, si->state, si->ib->flags, si->ob->flags);

 	si->ob->flags &= ~BF_SHUTW_NOW;
 	if (si->ob->flags & BF_SHUTW)
 		return;
 	si->ob->flags |= BF_SHUTW;
 	si->ob->wex = TICK_ETERNITY;
 	si->flags &= ~SI_FL_WAIT_DATA;

 	switch (si->state) {
 	case SI_ST_EST:
 		if (!(si->ib->flags & (BF_SHUTR|BF_DONT_READ)))
 			break;

 		/* fall through */
 	case SI_ST_CON:
 	case SI_ST_CER:
 		si->state = SI_ST_DIS;
 		/* fall through */
 	default:
 		si->flags &= ~SI_FL_WAIT_ROOM;
 		si->ib->flags |= BF_SHUTR;
 		si->ib->rex = TICK_ETERNITY;
 		si->exp = TICK_ETERNITY;
 	}

 	/* note that if the task exist, it must unregister itself once it runs */
 	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
 		task_wakeup(si->owner, TASK_WOKEN_IO);
 }

 /* default chk_rcv function for scheduled tasks */
 void stream_int_chk_rcv(struct stream_interface *si)
 {
 	struct buffer *ib = si->ib;

 	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
 		__FUNCTION__,
 		si, si->state, si->ib->flags, si->ob->flags);

 	if (unlikely(si->state != SI_ST_EST || (ib->flags & BF_SHUTR)))
 		return;

 	if (ib->flags & (BF_FULL|BF_HIJACK|BF_DONT_READ)) {
 		/* stop reading */
 		if ((ib->flags & (BF_FULL|BF_HIJACK|BF_DONT_READ)) == BF_FULL)
 			si->flags |= SI_FL_WAIT_ROOM;
 	}
 	else {
 		/* (re)start reading */
 		si->flags &= ~SI_FL_WAIT_ROOM;
 		if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
 			task_wakeup(si->owner, TASK_WOKEN_IO);
 	}
 }

 /* default chk_snd function for scheduled tasks */
 void stream_int_chk_snd(struct stream_interface *si)
 {
 	struct buffer *ob = si->ob;

 	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
 		__FUNCTION__,
 		si, si->state, si->ib->flags, si->ob->flags);

 	if (unlikely(si->state != SI_ST_EST || (si->ob->flags & BF_SHUTW)))
 		return;

 	if (!(si->flags & SI_FL_WAIT_DATA) ||        /* not waiting for data */
 	    (ob->flags & BF_OUT_EMPTY))              /* called with nothing to send ! */
 		return;

 	/* Otherwise there are remaining data to be sent in the buffer,
 	 * so we tell the handler.
 	 */
 	si->flags &= ~SI_FL_WAIT_DATA;
 	if (!tick_isset(ob->wex))
 		ob->wex = tick_add_ifset(now_ms, ob->wto);

 	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
 		task_wakeup(si->owner, TASK_WOKEN_IO);
 }

 /* Register a function to handle a stream_interface as part of the stream
  * interface's owner task, which is returned. The SI will wake it up everytime
  * it is solicited. The task's processing function must call the specified
  * function before returning. It must be deleted by the task handler using
  * stream_int_unregister_handler(), possibly from withing the function itself.
  */
 struct task *stream_int_register_handler(struct stream_interface *si,
 					 void (*fct)(struct stream_interface *))
 {
 	DPRINTF(stderr, "registering handler %p for si %p (was %p)\n", fct, si, si->owner);

 	si->update  = stream_int_update_embedded;
 	si->shutr   = stream_int_shutr;
 	si->shutw   = stream_int_shutw;
 	si->chk_rcv = stream_int_chk_rcv;
 	si->chk_snd = stream_int_chk_snd;
 	si->connect = NULL;
 	si->iohandler = fct;
 	si->flags |= SI_FL_WAIT_DATA;
 	return si->owner;
 }

 /* Register a function to handle a stream_interface as a standalone task. The
  * new task itself is returned and is assigned as si->owner. The stream_interface
  * pointer will be pointed to by the task's context. The handler can be detached
  * by using stream_int_unregister_handler().
  */
 struct task *stream_int_register_handler_task(struct stream_interface *si,
 					      struct task *(*fct)(struct task *))
 {
 	struct task *t;

 	DPRINTF(stderr, "registering handler %p for si %p (was %p)\n", fct, si, si->owner);

 	si->update  = stream_int_update;
 	si->shutr   = stream_int_shutr;
 	si->shutw   = stream_int_shutw;
 	si->chk_rcv = stream_int_chk_rcv;
 	si->chk_snd = stream_int_chk_snd;
 	si->connect = NULL;
 	si->iohandler = NULL; /* not used when running as an external task */
 	si->flags |= SI_FL_WAIT_DATA;

 	t = task_new();
 	si->owner = t;
 	if (!t)
 		return t;
 	t->process = fct;
 	t->context = si;
 	task_wakeup(si->owner, TASK_WOKEN_INIT);

 	return t;
 }

 /* Unregister a stream interface handler. This must be called by the handler task
  * itself when it detects that it is in the SI_ST_DIS state. This function can
  * both detach standalone handlers and embedded handlers.
  */
 void stream_int_unregister_handler(struct stream_interface *si)
 {
 	if (!si->iohandler && si->owner) {
 		/* external handler : kill the task */
 		task_delete(si->owner);
 		task_free(si->owner);
 	}
 	si->iohandler = NULL;
 	si->owner = NULL;
 }

 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* Functions managing stream_interface structures
	*
	* Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	*/

	#include <errno.h>
	#include <fcntl.h>
	#include <stdio.h>
	#include <stdlib.h>

	#include <sys/socket.h>
	#include <sys/stat.h>
	#include <sys/types.h>

	#include <common/compat.h>
	#include <common/config.h>
	#include <common/debug.h>
	#include <common/standard.h>
	#include <common/ticks.h>
	#include <common/time.h>

	#include <proto/buffers.h>
	#include <proto/fd.h>
	#include <proto/stream_interface.h>
	#include <proto/stream_sock.h>
	#include <proto/task.h>

	/*
	* This function only has to be called once after a wakeup event in case of
	* suspected timeout. It controls the stream interface timeouts and sets
	* si->flags accordingly. It does NOT close anything, as this timeout may
	* be used for any purpose. It returns 1 if the timeout fired, otherwise
	* zero.
	*/
	int stream_int_check_timeouts(struct stream_interface *si)
	{
	if (tick_is_expired(si->exp, now_ms)) {
	si->flags \|= SI_FL_EXP;
	return 1;
	}
	return 0;
	}

	/* to be called only when in SI_ST_DIS with SI_FL_ERR */
	void stream_int_report_error(struct stream_interface *si)
	{
	if (!si->err_type)
	si->err_type = SI_ET_DATA_ERR;

	si->ob->flags \|= BF_WRITE_ERROR;
	si->ib->flags \|= BF_READ_ERROR;
	}

	/*
	* Returns a message to the client ; the connection is shut down for read,
	* and the request is cleared so that no server connection can be initiated.
	* The buffer is marked for read shutdown on the other side to protect the
	* message, and the buffer write is enabled. The message is contained in a
	* "chunk". If it is null, then an empty message is used. The reply buffer does
	* not need to be empty before this, and its contents will not be overwritten.
	* The primary goal of this function is to return error messages to a client.
	*/
	void stream_int_retnclose(struct stream_interface si, const struct chunk msg)
	{
	buffer_auto_read(si->ib);
	buffer_abort(si->ib);
	buffer_auto_close(si->ib);
	buffer_erase(si->ib);
	if (likely(msg && msg->len))
	buffer_write(si->ob, msg->str, msg->len);

	si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
	buffer_auto_read(si->ob);
	buffer_auto_close(si->ob);
	buffer_shutr_now(si->ob);
	}

	/* default update function for scheduled tasks, not used for embedded tasks */
	void stream_int_update(struct stream_interface *si)
	{
	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
	__FUNCTION__,
	si, si->state, si->ib->flags, si->ob->flags);

	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
	task_wakeup(si->owner, TASK_WOKEN_IO);
	}

	/* default update function for embedded tasks, to be used at the end of the i/o handler */
	void stream_int_update_embedded(struct stream_interface *si)
	{
	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
	__FUNCTION__,
	si, si->state, si->ib->flags, si->ob->flags);

	if (si->state != SI_ST_EST)
	return;

	if ((si->ob->flags & (BF_OUT_EMPTY\|BF_SHUTW\|BF_HIJACK\|BF_SHUTW_NOW)) == (BF_OUT_EMPTY\|BF_SHUTW_NOW))
	si->shutw(si);

	if ((si->ob->flags & (BF_FULL\|BF_SHUTW\|BF_SHUTW_NOW\|BF_HIJACK)) == 0)
	si->flags \|= SI_FL_WAIT_DATA;

	/* we're almost sure that we need some space if the buffer is not
	* empty, even if it's not full, because the applets can't fill it.
	*/
	if ((si->ib->flags & (BF_SHUTR\|BF_OUT_EMPTY\|BF_DONT_READ)) == 0)
	si->flags \|= SI_FL_WAIT_ROOM;

	if (si->ob->flags & BF_WRITE_ACTIVITY) {
	if (tick_isset(si->ob->wex))
	si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
	}

	if (si->ib->flags & BF_READ_ACTIVITY \|\|
	(si->ob->flags & BF_WRITE_ACTIVITY && !(si->flags & SI_FL_INDEP_STR))) {
	if (tick_isset(si->ib->rex))
	si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
	}

	if (likely((si->ob->flags & (BF_SHUTW\|BF_WRITE_PARTIAL\|BF_FULL\|BF_DONT_READ)) == BF_WRITE_PARTIAL &&
	(si->ob->prod->flags & SI_FL_WAIT_ROOM)))
	si->ob->prod->chk_rcv(si->ob->prod);

	if (((si->ib->flags & (BF_READ_PARTIAL\|BF_OUT_EMPTY)) == BF_READ_PARTIAL) &&
	(si->ib->cons->flags & SI_FL_WAIT_DATA))
	si->ib->cons->chk_snd(si->ib->cons);

	/* Note that we're trying to wake up in two conditions here :
	* - special event, which needs the holder task attention
	* - status indicating that the applet can go on working. This
	* is rather hard because we might be blocking on output and
	* don't want to wake up on input and vice-versa. The idea is
	* the to only rely the changes the chk_* might have performed.
	*/
	if (/* check stream interface changes */
	(si->flags & SI_FL_ERR) \|\| si->state != SI_ST_EST \|\| si->ib->cons->state != SI_ST_EST \|\|
	/* check response buffer changes */
	(si->ib->flags & (BF_READ_NULL\|BF_READ_ERROR\|BF_READ_DONTWAIT)) \|\|
	((si->ib->flags & BF_READ_ACTIVITY) && !si->ib->to_forward) \|\|
	(!(si->ib->flags & BF_FULL) && (si->ib->flags & BF_WRITE_ACTIVITY) && si->ib->to_forward) \|\|
	/* check request buffer changes */
	(si->ob->flags & (BF_WRITE_ERROR)) \|\|
	((si->ob->flags & BF_WRITE_ACTIVITY) && (si->ob->flags & BF_OUT_EMPTY) && !si->ob->to_forward) \|\|
	(si->ob->flags & BF_READ_ACTIVITY)) {
	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
	task_wakeup(si->owner, TASK_WOKEN_IO);
	}
	}

	/* default shutr function for scheduled tasks */
	void stream_int_shutr(struct stream_interface *si)
	{
	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
	__FUNCTION__,
	si, si->state, si->ib->flags, si->ob->flags);

	si->ib->flags &= ~BF_SHUTR_NOW;
	if (si->ib->flags & BF_SHUTR)
	return;
	si->ib->flags \|= BF_SHUTR;
	si->ib->rex = TICK_ETERNITY;
	si->flags &= ~SI_FL_WAIT_ROOM;

	if (si->state != SI_ST_EST && si->state != SI_ST_CON)
	return;

	if (si->ob->flags & BF_SHUTW) {
	si->state = SI_ST_DIS;
	si->exp = TICK_ETERNITY;
	}

	/* note that if the task exist, it must unregister itself once it runs */
	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
	task_wakeup(si->owner, TASK_WOKEN_IO);
	}

	/* default shutw function for scheduled tasks */
	void stream_int_shutw(struct stream_interface *si)
	{
	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
	__FUNCTION__,
	si, si->state, si->ib->flags, si->ob->flags);

	si->ob->flags &= ~BF_SHUTW_NOW;
	if (si->ob->flags & BF_SHUTW)
	return;
	si->ob->flags \|= BF_SHUTW;
	si->ob->wex = TICK_ETERNITY;
	si->flags &= ~SI_FL_WAIT_DATA;

	switch (si->state) {
	case SI_ST_EST:
	if (!(si->ib->flags & (BF_SHUTR\|BF_DONT_READ)))
	break;

	/* fall through */
	case SI_ST_CON:
	case SI_ST_CER:
	si->state = SI_ST_DIS;
	/* fall through */
	default:
	si->flags &= ~SI_FL_WAIT_ROOM;
	si->ib->flags \|= BF_SHUTR;
	si->ib->rex = TICK_ETERNITY;
	si->exp = TICK_ETERNITY;
	}

	/* note that if the task exist, it must unregister itself once it runs */
	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
	task_wakeup(si->owner, TASK_WOKEN_IO);
	}

	/* default chk_rcv function for scheduled tasks */
	void stream_int_chk_rcv(struct stream_interface *si)
	{
	struct buffer *ib = si->ib;

	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
	__FUNCTION__,
	si, si->state, si->ib->flags, si->ob->flags);

	if (unlikely(si->state != SI_ST_EST \|\| (ib->flags & BF_SHUTR)))
	return;

	if (ib->flags & (BF_FULL\|BF_HIJACK\|BF_DONT_READ)) {
	/* stop reading */
	if ((ib->flags & (BF_FULL\|BF_HIJACK\|BF_DONT_READ)) == BF_FULL)
	si->flags \|= SI_FL_WAIT_ROOM;
	}
	else {
	/* (re)start reading */
	si->flags &= ~SI_FL_WAIT_ROOM;
	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
	task_wakeup(si->owner, TASK_WOKEN_IO);
	}
	}

	/* default chk_snd function for scheduled tasks */
	void stream_int_chk_snd(struct stream_interface *si)
	{
	struct buffer *ob = si->ob;

	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
	__FUNCTION__,
	si, si->state, si->ib->flags, si->ob->flags);

	if (unlikely(si->state != SI_ST_EST \|\| (si->ob->flags & BF_SHUTW)))
	return;

	if (!(si->flags & SI_FL_WAIT_DATA) \|\| /* not waiting for data */
	(ob->flags & BF_OUT_EMPTY)) /* called with nothing to send ! */
	return;

	/* Otherwise there are remaining data to be sent in the buffer,
	* so we tell the handler.
	*/
	si->flags &= ~SI_FL_WAIT_DATA;
	if (!tick_isset(ob->wex))
	ob->wex = tick_add_ifset(now_ms, ob->wto);

	if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
	task_wakeup(si->owner, TASK_WOKEN_IO);
	}

	/* Register a function to handle a stream_interface as part of the stream
	* interface's owner task, which is returned. The SI will wake it up everytime
	* it is solicited. The task's processing function must call the specified
	* function before returning. It must be deleted by the task handler using
	* stream_int_unregister_handler(), possibly from withing the function itself.
	*/
	struct task stream_int_register_handler(struct stream_interface si,
	void (fct)(struct stream_interface ))
	{
	DPRINTF(stderr, "registering handler %p for si %p (was %p)\n", fct, si, si->owner);

	si->update = stream_int_update_embedded;
	si->shutr = stream_int_shutr;
	si->shutw = stream_int_shutw;
	si->chk_rcv = stream_int_chk_rcv;
	si->chk_snd = stream_int_chk_snd;
	si->connect = NULL;
	si->iohandler = fct;
	si->flags \|= SI_FL_WAIT_DATA;
	return si->owner;
	}

	/* Register a function to handle a stream_interface as a standalone task. The
	* new task itself is returned and is assigned as si->owner. The stream_interface
	* pointer will be pointed to by the task's context. The handler can be detached
	* by using stream_int_unregister_handler().
	*/
	struct task stream_int_register_handler_task(struct stream_interface si,
	struct task (fct)(struct task *))
	{
	struct task *t;

	DPRINTF(stderr, "registering handler %p for si %p (was %p)\n", fct, si, si->owner);

	si->update = stream_int_update;
	si->shutr = stream_int_shutr;
	si->shutw = stream_int_shutw;
	si->chk_rcv = stream_int_chk_rcv;
	si->chk_snd = stream_int_chk_snd;
	si->connect = NULL;
	si->iohandler = NULL; /* not used when running as an external task */
	si->flags \|= SI_FL_WAIT_DATA;

	t = task_new();
	si->owner = t;
	if (!t)
	return t;
	t->process = fct;
	t->context = si;
	task_wakeup(si->owner, TASK_WOKEN_INIT);

	return t;
	}

	/* Unregister a stream interface handler. This must be called by the handler task
	* itself when it detects that it is in the SI_ST_DIS state. This function can
	* both detach standalone handlers and embedded handlers.
	*/
	void stream_int_unregister_handler(struct stream_interface *si)
	{
	if (!si->iohandler && si->owner) {
	/* external handler : kill the task */
	task_delete(si->owner);
	task_free(si->owner);
	}
	si->iohandler = NULL;
	si->owner = NULL;
	}

	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/