/*
	FreeRTOS V4.0.0 - Copyright (C) 2003-2006 Richard Barry.

	This file is part of the FreeRTOS distribution.

	FreeRTOS 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.

	FreeRTOS is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with FreeRTOS; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

	A special exception to the GPL can be applied should you wish to distribute
	a combined work that includes FreeRTOS, without being obliged to provide
	the source code for any proprietary components.  See the licensing section
	of http://www.FreeRTOS.org for full details of how and when the exception
	can be applied.

	***************************************************************************
	See http://www.FreeRTOS.org for documentation, latest information, license
	and contact details.  Please ensure to read the configuration and relevant
	port sections of the online documentation.
	***************************************************************************
*/
#ifndef CO_ROUTINE_H
#define CO_ROUTINE_H

#include "list.h"

/* Used to hide the implementation of the co-routine control block.  The 
control block structure however has to be included in the header due to 
the macro implementation of the co-routine functionality. */
typedef void * xCoRoutineHandle;

/* Defines the prototype to which co-routine functions must conform. */
typedef void (*crCOROUTINE_CODE)( xCoRoutineHandle, unsigned portBASE_TYPE );

typedef struct corCoRoutineControlBlock
{
	crCOROUTINE_CODE 		pxCoRoutineFunction;
	xListItem				xGenericListItem;	/*< List item used to place the CRCB in ready and blocked queues. */
	xListItem				xEventListItem;		/*< List item used to place the CRCB in event lists. */
	unsigned portBASE_TYPE 	uxPriority;			/*< The priority of the co-routine in relation to other co-routines. */
	unsigned portBASE_TYPE 	uxIndex;			/*< Used to distinguish between co-routines when multiple co-routines use the same co-routine function. */
	unsigned portSHORT 		uxState;			/*< Used internally by the co-routine implementation. */
} corCRCB; /* Co-routine control block.  Note must be identical in size down to uxPriority with tskTCB. */

/**
 * croutine. h
 *<pre>
 portBASE_TYPE xCoRoutineCreate(
                                 crCOROUTINE_CODE pxCoRoutineCode,
                                 unsigned portBASE_TYPE uxPriority,
                                 unsigned portBASE_TYPE uxIndex
                               );</pre>
 *
 * Create a new co-routine and add it to the list of co-routines that are 
 * ready to run.
 *
 * @param pxCoRoutineCode Pointer to the co-routine function.  Co-routine 
 * functions require special syntax - see the co-routine section of the WEB 
 * documentation for more information.
 *
 * @param uxPriority The priority with respect to other co-routines at which 
 *  the co-routine will run.
 *
 * @param uxIndex Used to distinguish between different co-routines that
 * execute the same function.  See the example below and the co-routine section
 * of the WEB documentation for further information.
 *
 * @return pdPASS if the co-routine was successfully created and added to a ready
 * list, otherwise an error code defined with ProjDefs.h.
 *
 * Example usage:
   <pre>
 // Co-routine to be created.
 void vFlashCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
 {
 // Variables in co-routines must be declared static if they must maintain value across a blocking call.
 // This may not be necessary for const variables.
 static const char cLedToFlash[ 2 ] = { 5, 6 };
 static const portTickType xTimeToDelay[ 2 ] = { 200, 400 };

     // Must start every co-routine with a call to crSTART();
     crSTART( xHandle );

     for( ;; )
     {
         // This co-routine just delays for a fixed period, then toggles
         // an LED.  Two co-routines are created using this function, so
         // the uxIndex parameter is used to tell the co-routine which
         // LED to flash and how long to delay.  This assumes xQueue has
         // already been created.
         vParTestToggleLED( cLedToFlash[ uxIndex ] );
         crDELAY( xHandle, uxFlashRates[ uxIndex ] );
     }

     // Must end every co-routine with a call to crEND();
     crEND();
 }

 // Function that creates two co-routines.
 void vOtherFunction( void )
 {
 unsigned char ucParameterToPass;
 xTaskHandle xHandle;
		
     // Create two co-routines at priority 0.  The first is given index 0
     // so (from the code above) toggles LED 5 every 200 ticks.  The second
     // is given index 1 so toggles LED 6 every 400 ticks.
     for( uxIndex = 0; uxIndex < 2; uxIndex++ )
     {
         xCoRoutineCreate( vFlashCoRoutine, 0, uxIndex );
     }  
 }
   </pre>
 * \defgroup xCoRoutineCreate xCoRoutineCreate
 * \ingroup Tasks
 */
portBASE_TYPE xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, unsigned portBASE_TYPE uxPriority, unsigned portBASE_TYPE uxIndex );


/**
 * croutine. h
 *<pre>
 void vCoRoutineSchedule( void );</pre>
 *
 * Run a co-routine.
 * 
 * vCoRoutineSchedule() executes the highest priority co-routine that is able
 * to run.  The co-routine will execute until it either blocks, yields or is
 * preempted by a task.  Co-routines execute cooperatively so one 
 * co-routine cannot be preempted by another, but can be preempted by a task.
 *
 * If an application comprises of both tasks and co-routines then 
 * vCoRoutineSchedule should be called from the idle task (in an idle task 
 * hook).
 *
 * Example usage:
   <pre>
 // This idle task hook will schedule a co-routine each time it is called.
 // The rest of the idle task will execute between co-routine calls.
 void vApplicationIdleHook( void )
 {
	vCoRoutineSchedule();
 }

 // Alternatively, if you do not require any other part of the idle task to 
 // execute, the idle task hook can call vCoRoutineScheduler() within an
 // infinite loop.
 void vApplicationIdleHook( void )
 {
    for( ;; )
    {
        vCoRoutineSchedule();
    }
 }
 </pre>
 * \defgroup vCoRoutineSchedule vCoRoutineSchedule
 * \ingroup Tasks
 */
void vCoRoutineSchedule( void );

/**
 * croutine. h
 * <pre>
 crSTART( xCoRoutineHandle xHandle );</pre>
 *
 * This macro MUST always be called at the start of a co-routine function.
 *
 * Example usage:
   <pre>
 // Co-routine to be created.
 void vACoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
 {
 // Variables in co-routines must be declared static if they must maintain value across a blocking call.
 static portLONG ulAVariable;

     // Must start every co-routine with a call to crSTART();
     crSTART( xHandle );

     for( ;; )
     {
          // Co-routine functionality goes here.
     }

     // Must end every co-routine with a call to crEND();
     crEND();
 }</pre>
 * \defgroup crSTART crSTART
 * \ingroup Tasks
 */
#define crSTART( pxCRCB ) switch( ( ( corCRCB * )pxCRCB )->uxState ) { case 0:

/**
 * croutine. h
 * <pre>
 crEND();</pre>
 *
 * This macro MUST always be called at the end of a co-routine function.
 *
 * Example usage:
   <pre>
 // Co-routine to be created.
 void vACoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
 {
 // Variables in co-routines must be declared static if they must maintain value across a blocking call.
 static portLONG ulAVariable;

     // Must start every co-routine with a call to crSTART();
     crSTART( xHandle );

     for( ;; )
     {
          // Co-routine functionality goes here.
     }

     // Must end every co-routine with a call to crEND();
     crEND();
 }</pre>
 * \defgroup crSTART crSTART
 * \ingroup Tasks
 */
#define crEND() }

/*
 * These macros are intended for internal use by the co-routine implementation 
 * only.  The macros should not be used directly by application writers.
 */
#define crSET_STATE0( xHandle ) ( ( corCRCB * )xHandle)->uxState = (__LINE__ * 2); return; case (__LINE__ * 2):
#define crSET_STATE1( xHandle ) ( ( corCRCB * )xHandle)->uxState = ((__LINE__ * 2)+1); return; case ((__LINE__ * 2)+1):

/**
 * croutine. h
 *<pre>
 crDELAY( xCoRoutineHandle xHandle, portTickType xTicksToDelay );</pre>
 *
 * Delay a co-routine for a fixed period of time.
 *
 * crDELAY can only be called from the co-routine function itself - not
 * from within a function called by the co-routine function.  This is because
 * co-routines do not maintain their own stack.
 *
 * @param xHandle The handle of the co-routine to delay.  This is the xHandle
 * parameter of the co-routine function.
 *
 * @param xTickToDelay The number of ticks that the co-routine should delay 
 * for.  The actual amount of time this equates to is defined by 
 * configTICK_RATE_HZ (set in FreeRTOSConfig.h).  The constant portTICK_RATE_MS
 * can be used to convert ticks to milliseconds.
 *
 * Example usage:
   <pre>
 // Co-routine to be created.
 void vACoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
 {
 // Variables in co-routines must be declared static if they must maintain value across a blocking call.
 // This may not be necessary for const variables.
 // We are to delay for 200ms.
 static const xTickType xDelayTime = 200 / portTICK_RATE_MS;

     // Must start every co-routine with a call to crSTART();
     crSTART( xHandle );

     for( ;; )
     {
        // Delay for 200ms.
        crDELAY( xHandle, xDelayTime );

        // Do something here.
     }

     // Must end every co-routine with a call to crEND();
     crEND();
 }</pre>
 * \defgroup crDELAY crDELAY
 * \ingroup Tasks
 */
#define crDELAY( xHandle, xTicksToDelay )												\
	if( xTicksToDelay > 0 )																\
	{																					\
		vCoRoutineAddToDelayedList( xTicksToDelay, NULL );								\
	}																					\
	crSET_STATE0( xHandle );

/**
 * <pre>
 crQUEUE_SEND( 
                  xCoRoutineHandle xHandle, 
                  xQueueHandle pxQueue, 
                  void *pvItemToQueue, 
                  portTickType xTicksToWait, 
                  portBASE_TYPE *pxResult 
             )</pre>
 *
 * The macro's crQUEUE_SEND() and crQUEUE_RECEIVE() are the co-routine 
 * equivalent to the xQueueSend() and xQueueReceive() functions used by tasks.  
 *
 * crQUEUE_SEND and crQUEUE_RECEIVE can only be used from a co-routine whereas  
 * xQueueSend() and xQueueReceive() can only be used from tasks.
 *
 * crQUEUE_SEND can only be called from the co-routine function itself - not
 * from within a function called by the co-routine function.  This is because
 * co-routines do not maintain their own stack.
 *
 * See the co-routine section of the WEB documentation for information on 
 * passing data between tasks and co-routines and between ISR's and 
 * co-routines.
 *
 * @param xHandle The handle of the calling co-routine.  This is the xHandle
 * parameter of the co-routine function.
 *
 * @param pxQueue The handle of the queue on which the data will be posted.  
 * The handle is obtained as the return value when the queue is created using 
 * the xQueueCreate() API function.
 *
 * @param pvItemToQueue A pointer to the data being posted onto the queue.
 * The number of bytes of each queued item is specified when the queue is
 * created.  This number of bytes is copied from pvItemToQueue into the queue
 * itself.
 *
 * @param xTickToDelay The number of ticks that the co-routine should block 
 * to wait for space to become available on the queue, should space not be
 * available immediately. The actual amount of time this equates to is defined 
 * by configTICK_RATE_HZ (set in FreeRTOSConfig.h).  The constant 
 * portTICK_RATE_MS can be used to convert ticks to milliseconds (see example
 * below).
 *
 * @param pxResult The variable pointed to by pxResult will be set to pdPASS if
 * data was successfully posted onto the queue, otherwise it will be set to an 
 * error defined within ProjDefs.h.
 *
 * Example usage:
   <pre>
 // Co-routine function that blocks for a fixed period then posts a number onto
 // a queue.
 static void prvCoRoutineFlashTask( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
 {
 // Variables in co-routines must be declared static if they must maintain value across a blocking call.
 static portBASE_TYPE xNumberToPost = 0;
 static portBASE_TYPE xResult;

    // Co-routines must begin with a call to crSTART().
    crSTART( xHandle );

    for( ;; )
    {
        // This assumes the queue has already been created.
        crQUEUE_SEND( xHandle, xCoRoutineQueue, &xNumberToPost, NO_DELAY, &xResult );