2 FreeRTOS.org V5.1.0 - Copyright (C) 2003-2008 Richard Barry.
\r
4 This file is part of the FreeRTOS.org distribution.
\r
6 FreeRTOS.org is free software; you can redistribute it and/or modify
\r
7 it under the terms of the GNU General Public License as published by
\r
8 the Free Software Foundation; either version 2 of the License, or
\r
9 (at your option) any later version.
\r
11 FreeRTOS.org is distributed in the hope that it will be useful,
\r
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
\r
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\r
14 GNU General Public License for more details.
\r
16 You should have received a copy of the GNU General Public License
\r
17 along with FreeRTOS.org; if not, write to the Free Software
\r
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
\r
20 A special exception to the GPL can be applied should you wish to distribute
\r
21 a combined work that includes FreeRTOS.org, without being obliged to provide
\r
22 the source code for any proprietary components. See the licensing section
\r
23 of http://www.FreeRTOS.org for full details of how and when the exception
\r
26 ***************************************************************************
\r
27 ***************************************************************************
\r
29 * SAVE TIME AND MONEY! We can port FreeRTOS.org to your own hardware, *
\r
30 * and even write all or part of your application on your behalf. *
\r
31 * See http://www.OpenRTOS.com for details of the services we provide to *
\r
32 * expedite your project. *
\r
34 ***************************************************************************
\r
35 ***************************************************************************
\r
37 Please ensure to read the configuration and relevant port sections of the
\r
38 online documentation.
\r
40 http://www.FreeRTOS.org - Documentation, latest information, license and
\r
43 http://www.SafeRTOS.com - A version that is certified for use in safety
\r
46 http://www.OpenRTOS.com - Commercial support, development, porting,
\r
47 licensing and training services.
\r
51 * Create a single persistent task which periodically dynamically creates another
\r
52 * four tasks. The original task is called the creator task, the four tasks it
\r
53 * creates are called suicidal tasks.
\r
55 * Two of the created suicidal tasks kill one other suicidal task before killing
\r
56 * themselves - leaving just the original task remaining.
\r
58 * The creator task must be spawned after all of the other demo application tasks
\r
59 * as it keeps a check on the number of tasks under the scheduler control. The
\r
60 * number of tasks it expects to see running should never be greater than the
\r
61 * number of tasks that were in existence when the creator task was spawned, plus
\r
62 * one set of four suicidal tasks. If this number is exceeded an error is flagged.
\r
64 * \page DeathC death.c
\r
65 * \ingroup DemoFiles
\r
72 + Delay periods are now specified using variables and constants of
\r
73 portTickType rather than unsigned portLONG.
\r
78 /* Scheduler include files. */
\r
79 #include "FreeRTOS.h"
\r
82 /* Demo program include files. */
\r
86 #define deathSTACK_SIZE ( ( unsigned portSHORT ) 512 )
\r
88 /* The task originally created which is responsible for periodically dynamically
\r
89 creating another four tasks. */
\r
90 static void vCreateTasks( void *pvParameters );
\r
92 /* The task function of the dynamically created tasks. */
\r
93 static void vSuicidalTask( void *pvParameters );
\r
95 /* A variable which is incremented every time the dynamic tasks are created. This
\r
96 is used to check that the task is still running. */
\r
97 static volatile portSHORT sCreationCount = 0;
\r
99 /* Used to store the number of tasks that were originally running so the creator
\r
100 task can tell if any of the suicidal tasks have failed to die. */
\r
101 static volatile unsigned portBASE_TYPE uxTasksRunningAtStart = 0;
\r
102 static const unsigned portBASE_TYPE uxMaxNumberOfExtraTasksRunning = 5;
\r
104 /* Used to store a handle to the tasks that should be killed by a suicidal task,
\r
105 before it kills itself. */
\r
106 xTaskHandle xCreatedTask1, xCreatedTask2;
\r
108 /*-----------------------------------------------------------*/
\r
110 void vCreateSuicidalTasks( unsigned portBASE_TYPE uxPriority )
\r
112 unsigned portBASE_TYPE *puxPriority;
\r
114 /* Create the Creator tasks - passing in as a parameter the priority at which
\r
115 the suicidal tasks should be created. */
\r
116 puxPriority = ( unsigned portBASE_TYPE * ) pvPortMalloc( sizeof( unsigned portBASE_TYPE ) );
\r
117 *puxPriority = uxPriority;
\r
119 xTaskCreate( vCreateTasks, "CREATOR", deathSTACK_SIZE, ( void * ) puxPriority, uxPriority, NULL );
\r
121 /* Record the number of tasks that are running now so we know if any of the
\r
122 suicidal tasks have failed to be killed. */
\r
123 uxTasksRunningAtStart = uxTaskGetNumberOfTasks();
\r
125 /*-----------------------------------------------------------*/
\r
127 static void vSuicidalTask( void *pvParameters )
\r
130 xTaskHandle xTaskToKill;
\r
131 const portTickType xDelay = ( portTickType ) 500 / portTICK_RATE_MS;
\r
133 if( pvParameters != NULL )
\r
135 /* This task is periodically created four times. Tow created tasks are
\r
136 passed a handle to the other task so it can kill it before killing itself.
\r
137 The other task is passed in null. */
\r
138 xTaskToKill = *( xTaskHandle* )pvParameters;
\r
142 xTaskToKill = NULL;
\r
147 /* Do something random just to use some stack and registers. */
\r
151 vTaskDelay( xDelay );
\r
153 if( xTaskToKill != NULL )
\r
155 /* Make sure the other task has a go before we delete it. */
\r
156 vTaskDelay( ( portTickType ) 0 );
\r
157 /* Kill the other task that was created by vCreateTasks(). */
\r
158 vTaskDelete( xTaskToKill );
\r
159 /* Kill ourselves. */
\r
160 vTaskDelete( NULL );
\r
163 }/*lint !e818 !e550 Function prototype must be as per standard for task functions. */
\r
164 /*-----------------------------------------------------------*/
\r
166 static void vCreateTasks( void *pvParameters )
\r
168 const portTickType xDelay = ( portTickType ) 1000 / portTICK_RATE_MS;
\r
169 unsigned portBASE_TYPE uxPriority;
\r
170 const portCHAR * const pcTaskStartMsg = "Create task started.\r\n";
\r
172 /* Queue a message for printing to say the task has started. */
\r
173 vPrintDisplayMessage( &pcTaskStartMsg );
\r
175 uxPriority = *( unsigned portBASE_TYPE * ) pvParameters;
\r
176 vPortFree( pvParameters );
\r
180 /* Just loop round, delaying then creating the four suicidal tasks. */
\r
181 vTaskDelay( xDelay );
\r
183 xTaskCreate( vSuicidalTask, "SUICIDE1", deathSTACK_SIZE, NULL, uxPriority, &xCreatedTask1 );
\r
184 xTaskCreate( vSuicidalTask, "SUICIDE2", deathSTACK_SIZE, &xCreatedTask1, uxPriority, NULL );
\r
186 xTaskCreate( vSuicidalTask, "SUICIDE1", deathSTACK_SIZE, NULL, uxPriority, &xCreatedTask2 );
\r
187 xTaskCreate( vSuicidalTask, "SUICIDE2", deathSTACK_SIZE, &xCreatedTask2, uxPriority, NULL );
\r
192 /*-----------------------------------------------------------*/
\r
194 /* This is called to check that the creator task is still running and that there
\r
195 are not any more than four extra tasks. */
\r
196 portBASE_TYPE xIsCreateTaskStillRunning( void )
\r
198 static portSHORT sLastCreationCount = 0;
\r
199 portSHORT sReturn = pdTRUE;
\r
200 unsigned portBASE_TYPE uxTasksRunningNow;
\r
202 if( sLastCreationCount == sCreationCount )
\r
207 uxTasksRunningNow = uxTaskGetNumberOfTasks();
\r
209 if( uxTasksRunningNow < uxTasksRunningAtStart )
\r
213 else if( ( uxTasksRunningNow - uxTasksRunningAtStart ) > uxMaxNumberOfExtraTasksRunning )
\r
219 /* Everything is okay. */
\r