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diff --git a/libraries/FreeRTOS/utility/task.h b/libraries/FreeRTOS/utility/task.h new file mode 100755 index 0000000..96ba68e --- /dev/null +++ b/libraries/FreeRTOS/utility/task.h @@ -0,0 +1,1307 @@ +/* + FreeRTOS V7.0.1 - Copyright (C) 2011 Real Time Engineers Ltd. + + + FreeRTOS supports many tools and architectures. V7.0.0 is sponsored by: + Atollic AB - Atollic provides professional embedded systems development + tools for C/C++ development, code analysis and test automation. + See http://www.atollic.com + + + *************************************************************************** + * * + * FreeRTOS tutorial books are available in pdf and paperback. * + * Complete, revised, and edited pdf reference manuals are also * + * available. * + * * + * Purchasing FreeRTOS documentation will not only help you, by * + * ensuring you get running as quickly as possible and with an * + * in-depth knowledge of how to use FreeRTOS, it will also help * + * the FreeRTOS project to continue with its mission of providing * + * professional grade, cross platform, de facto standard solutions * + * for microcontrollers - completely free of charge! * + * * + * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * + * * + * Thank you for using FreeRTOS, and thank you for your support! * + * * + *************************************************************************** + + + 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 (version 2) as published by the + Free Software Foundation AND MODIFIED BY the FreeRTOS exception. + >>>NOTE<<< The modification to the GPL is included to allow you to + distribute a combined work that includes FreeRTOS without being obliged to + provide the source code for proprietary components outside of the FreeRTOS + kernel. 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 and the FreeRTOS license exception along with FreeRTOS; if not it + can be viewed here: http://www.freertos.org/a00114.html and also obtained + by writing to Richard Barry, contact details for whom are available on the + FreeRTOS WEB site. + + 1 tab == 4 spaces! + + http://www.FreeRTOS.org - Documentation, latest information, license and + contact details. + + http://www.SafeRTOS.com - A version that is certified for use in safety + critical systems. + + http://www.OpenRTOS.com - Commercial support, development, porting, + licensing and training services. +*/ + + +#ifndef TASK_H +#define TASK_H + +#ifndef INC_FREERTOS_H + #error "include FreeRTOS.h must appear in source files before include task.h" +#endif + +#include "portable.h" +#include "list.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/*----------------------------------------------------------- + * MACROS AND DEFINITIONS + *----------------------------------------------------------*/ + +#define tskKERNEL_VERSION_NUMBER "V7.0.1" + +/** + * task. h + * + * Type by which tasks are referenced. For example, a call to xTaskCreate + * returns (via a pointer parameter) an xTaskHandle variable that can then + * be used as a parameter to vTaskDelete to delete the task. + * + * \page xTaskHandle xTaskHandle + * \ingroup Tasks + */ +typedef void * xTaskHandle; + +/* + * Used internally only. + */ +typedef struct xTIME_OUT +{ + portBASE_TYPE xOverflowCount; + portTickType xTimeOnEntering; +} xTimeOutType; + +/* + * Defines the memory ranges allocated to the task when an MPU is used. + */ +typedef struct xMEMORY_REGION +{ + void *pvBaseAddress; + unsigned long ulLengthInBytes; + unsigned long ulParameters; +} xMemoryRegion; + +/* + * Parameters required to create an MPU protected task. + */ +typedef struct xTASK_PARAMTERS +{ + pdTASK_CODE pvTaskCode; + const signed char * const pcName; + unsigned short usStackDepth; + void *pvParameters; + unsigned portBASE_TYPE uxPriority; + portSTACK_TYPE *puxStackBuffer; + xMemoryRegion xRegions[ portNUM_CONFIGURABLE_REGIONS ]; +} xTaskParameters; + +/* + * Defines the priority used by the idle task. This must not be modified. + * + * \ingroup TaskUtils + */ +#define tskIDLE_PRIORITY ( ( unsigned portBASE_TYPE ) 0U ) + +/** + * task. h + * + * Macro for forcing a context switch. + * + * \page taskYIELD taskYIELD + * \ingroup SchedulerControl + */ +#define taskYIELD() portYIELD() + +/** + * task. h + * + * Macro to mark the start of a critical code region. Preemptive context + * switches cannot occur when in a critical region. + * + * NOTE: This may alter the stack (depending on the portable implementation) + * so must be used with care! + * + * \page taskENTER_CRITICAL taskENTER_CRITICAL + * \ingroup SchedulerControl + */ +#define taskENTER_CRITICAL() portENTER_CRITICAL() + +/** + * task. h + * + * Macro to mark the end of a critical code region. Preemptive context + * switches cannot occur when in a critical region. + * + * NOTE: This may alter the stack (depending on the portable implementation) + * so must be used with care! + * + * \page taskEXIT_CRITICAL taskEXIT_CRITICAL + * \ingroup SchedulerControl + */ +#define taskEXIT_CRITICAL() portEXIT_CRITICAL() + +/** + * task. h + * + * Macro to disable all maskable interrupts. + * + * \page taskDISABLE_INTERRUPTS taskDISABLE_INTERRUPTS + * \ingroup SchedulerControl + */ +#define taskDISABLE_INTERRUPTS() portDISABLE_INTERRUPTS() + +/** + * task. h + * + * Macro to enable microcontroller interrupts. + * + * \page taskENABLE_INTERRUPTS taskENABLE_INTERRUPTS + * \ingroup SchedulerControl + */ +#define taskENABLE_INTERRUPTS() portENABLE_INTERRUPTS() + +/* Definitions returned by xTaskGetSchedulerState(). */ +#define taskSCHEDULER_NOT_STARTED 0 +#define taskSCHEDULER_RUNNING 1 +#define taskSCHEDULER_SUSPENDED 2 + +/*----------------------------------------------------------- + * TASK CREATION API + *----------------------------------------------------------*/ + +/** + * task. h + *<pre> + portBASE_TYPE xTaskCreate( + pdTASK_CODE pvTaskCode, + const char * const pcName, + unsigned short usStackDepth, + void *pvParameters, + unsigned portBASE_TYPE uxPriority, + xTaskHandle *pvCreatedTask + );</pre> + * + * Create a new task and add it to the list of tasks that are ready to run. + * + * xTaskCreate() can only be used to create a task that has unrestricted + * access to the entire microcontroller memory map. Systems that include MPU + * support can alternatively create an MPU constrained task using + * xTaskCreateRestricted(). + * + * @param pvTaskCode Pointer to the task entry function. Tasks + * must be implemented to never return (i.e. continuous loop). + * + * @param pcName A descriptive name for the task. This is mainly used to + * facilitate debugging. Max length defined by tskMAX_TASK_NAME_LEN - default + * is 16. + * + * @param usStackDepth The size of the task stack specified as the number of + * variables the stack can hold - not the number of bytes. For example, if + * the stack is 16 bits wide and usStackDepth is defined as 100, 200 bytes + * will be allocated for stack storage. + * + * @param pvParameters Pointer that will be used as the parameter for the task + * being created. + * + * @param uxPriority The priority at which the task should run. Systems that + * include MPU support can optionally create tasks in a privileged (system) + * mode by setting bit portPRIVILEGE_BIT of the priority parameter. For + * example, to create a privileged task at priority 2 the uxPriority parameter + * should be set to ( 2 | portPRIVILEGE_BIT ). + * + * @param pvCreatedTask Used to pass back a handle by which the created task + * can be referenced. + * + * @return pdPASS if the task was successfully created and added to a ready + * list, otherwise an error code defined in the file errors. h + * + * Example usage: + <pre> + // Task to be created. + void vTaskCode( void * pvParameters ) + { + for( ;; ) + { + // Task code goes here. + } + } + + // Function that creates a task. + void vOtherFunction( void ) + { + static unsigned char ucParameterToPass; + xTaskHandle xHandle; + + // Create the task, storing the handle. Note that the passed parameter ucParameterToPass + // must exist for the lifetime of the task, so in this case is declared static. If it was just an + // an automatic stack variable it might no longer exist, or at least have been corrupted, by the time + // the new task attempts to access it. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle ); + + // Use the handle to delete the task. + vTaskDelete( xHandle ); + } + </pre> + * \defgroup xTaskCreate xTaskCreate + * \ingroup Tasks + */ +#define xTaskCreate( pvTaskCode, pcName, usStackDepth, pvParameters, uxPriority, pxCreatedTask ) xTaskGenericCreate( ( pvTaskCode ), ( pcName ), ( usStackDepth ), ( pvParameters ), ( uxPriority ), ( pxCreatedTask ), ( NULL ), ( NULL ) ) + +/** + * task. h + *<pre> + portBASE_TYPE xTaskCreateRestricted( xTaskParameters *pxTaskDefinition, xTaskHandle *pxCreatedTask );</pre> + * + * xTaskCreateRestricted() should only be used in systems that include an MPU + * implementation. + * + * Create a new task and add it to the list of tasks that are ready to run. + * The function parameters define the memory regions and associated access + * permissions allocated to the task. + * + * @param pxTaskDefinition Pointer to a structure that contains a member + * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API + * documentation) plus an optional stack buffer and the memory region + * definitions. + * + * @param pxCreatedTask Used to pass back a handle by which the created task + * can be referenced. + * + * @return pdPASS if the task was successfully created and added to a ready + * list, otherwise an error code defined in the file errors. h + * + * Example usage: + <pre> +// Create an xTaskParameters structure that defines the task to be created. +static const xTaskParameters xCheckTaskParameters = +{ + vATask, // pvTaskCode - the function that implements the task. + "ATask", // pcName - just a text name for the task to assist debugging. + 100, // usStackDepth - the stack size DEFINED IN WORDS. + NULL, // pvParameters - passed into the task function as the function parameters. + ( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state. + cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack. + + // xRegions - Allocate up to three separate memory regions for access by + // the task, with appropriate access permissions. Different processors have + // different memory alignment requirements - refer to the FreeRTOS documentation + // for full information. + { + // Base address Length Parameters + { cReadWriteArray, 32, portMPU_REGION_READ_WRITE }, + { cReadOnlyArray, 32, portMPU_REGION_READ_ONLY }, + { cPrivilegedOnlyAccessArray, 128, portMPU_REGION_PRIVILEGED_READ_WRITE } + } +}; + +int main( void ) +{ +xTaskHandle xHandle; + + // Create a task from the const structure defined above. The task handle + // is requested (the second parameter is not NULL) but in this case just for + // demonstration purposes as its not actually used. + xTaskCreateRestricted( &xRegTest1Parameters, &xHandle ); + + // Start the scheduler. + vTaskStartScheduler(); + + // Will only get here if there was insufficient memory to create the idle + // task. + for( ;; ); +} + </pre> + * \defgroup xTaskCreateRestricted xTaskCreateRestricted + * \ingroup Tasks + */ +#define xTaskCreateRestricted( x, pxCreatedTask ) xTaskGenericCreate( ((x)->pvTaskCode), ((x)->pcName), ((x)->usStackDepth), ((x)->pvParameters), ((x)->uxPriority), (pxCreatedTask), ((x)->puxStackBuffer), ((x)->xRegions) ) + +/** + * task. h + *<pre> + void vTaskAllocateMPURegions( xTaskHandle xTask, const xMemoryRegion * const pxRegions );</pre> + * + * Memory regions are assigned to a restricted task when the task is created by + * a call to xTaskCreateRestricted(). These regions can be redefined using + * vTaskAllocateMPURegions(). + * + * @param xTask The handle of the task being updated. + * + * @param xRegions A pointer to an xMemoryRegion structure that contains the + * new memory region definitions. + * + * Example usage: + <pre> +// Define an array of xMemoryRegion structures that configures an MPU region +// allowing read/write access for 1024 bytes starting at the beginning of the +// ucOneKByte array. The other two of the maximum 3 definable regions are +// unused so set to zero. +static const xMemoryRegion xAltRegions[ portNUM_CONFIGURABLE_REGIONS ] = +{ + // Base address Length Parameters + { ucOneKByte, 1024, portMPU_REGION_READ_WRITE }, + { 0, 0, 0 }, + { 0, 0, 0 } +}; + +void vATask( void *pvParameters ) +{ + // This task was created such that it has access to certain regions of + // memory as defined by the MPU configuration. At some point it is + // desired that these MPU regions are replaced with that defined in the + // xAltRegions const struct above. Use a call to vTaskAllocateMPURegions() + // for this purpose. NULL is used as the task handle to indicate that this + // function should modify the MPU regions of the calling task. + vTaskAllocateMPURegions( NULL, xAltRegions ); + + // Now the task can continue its function, but from this point on can only + // access its stack and the ucOneKByte array (unless any other statically + // defined or shared regions have been declared elsewhere). +} + </pre> + * \defgroup xTaskCreateRestricted xTaskCreateRestricted + * \ingroup Tasks + */ +void vTaskAllocateMPURegions( xTaskHandle xTask, const xMemoryRegion * const pxRegions ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void vTaskDelete( xTaskHandle pxTask );</pre> + * + * INCLUDE_vTaskDelete must be defined as 1 for this function to be available. + * See the configuration section for more information. + * + * Remove a task from the RTOS real time kernels management. The task being + * deleted will be removed from all ready, blocked, suspended and event lists. + * + * NOTE: The idle task is responsible for freeing the kernel allocated + * memory from tasks that have been deleted. It is therefore important that + * the idle task is not starved of microcontroller processing time if your + * application makes any calls to vTaskDelete (). Memory allocated by the + * task code is not automatically freed, and should be freed before the task + * is deleted. + * + * See the demo application file death.c for sample code that utilises + * vTaskDelete (). + * + * @param pxTask The handle of the task to be deleted. Passing NULL will + * cause the calling task to be deleted. + * + * Example usage: + <pre> + void vOtherFunction( void ) + { + xTaskHandle xHandle; + + // Create the task, storing the handle. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle ); + + // Use the handle to delete the task. + vTaskDelete( xHandle ); + } + </pre> + * \defgroup vTaskDelete vTaskDelete + * \ingroup Tasks + */ +void vTaskDelete( xTaskHandle pxTaskToDelete ) PRIVILEGED_FUNCTION; + +/*----------------------------------------------------------- + * TASK CONTROL API + *----------------------------------------------------------*/ + +/** + * task. h + * <pre>void vTaskDelay( portTickType xTicksToDelay );</pre> + * + * Delay a task for a given number of ticks. The actual time that the + * task remains blocked depends on the tick rate. The constant + * portTICK_RATE_MS can be used to calculate real time from the tick + * rate - with the resolution of one tick period. + * + * INCLUDE_vTaskDelay must be defined as 1 for this function to be available. + * See the configuration section for more information. + * + * + * vTaskDelay() specifies a time at which the task wishes to unblock relative to + * the time at which vTaskDelay() is called. For example, specifying a block + * period of 100 ticks will cause the task to unblock 100 ticks after + * vTaskDelay() is called. vTaskDelay() does not therefore provide a good method + * of controlling the frequency of a cyclical task as the path taken through the + * code, as well as other task and interrupt activity, will effect the frequency + * at which vTaskDelay() gets called and therefore the time at which the task + * next executes. See vTaskDelayUntil() for an alternative API function designed + * to facilitate fixed frequency execution. It does this by specifying an + * absolute time (rather than a relative time) at which the calling task should + * unblock. + * + * @param xTicksToDelay The amount of time, in tick periods, that + * the calling task should block. + * + * Example usage: + + void vTaskFunction( void * pvParameters ) + { + void vTaskFunction( void * pvParameters ) + { + // Block for 500ms. + const portTickType xDelay = 500 / portTICK_RATE_MS; + + for( ;; ) + { + // Simply toggle the LED every 500ms, blocking between each toggle. + vToggleLED(); + vTaskDelay( xDelay ); + } + } + + * \defgroup vTaskDelay vTaskDelay + * \ingroup TaskCtrl + */ +void vTaskDelay( portTickType xTicksToDelay ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void vTaskDelayUntil( portTickType *pxPreviousWakeTime, portTickType xTimeIncrement );</pre> + * + * INCLUDE_vTaskDelayUntil must be defined as 1 for this function to be available. + * See the configuration section for more information. + * + * Delay a task until a specified time. This function can be used by cyclical + * tasks to ensure a constant execution frequency. + * + * This function differs from vTaskDelay () in one important aspect: vTaskDelay () will + * cause a task to block for the specified number of ticks from the time vTaskDelay () is + * called. It is therefore difficult to use vTaskDelay () by itself to generate a fixed + * execution frequency as the time between a task starting to execute and that task + * calling vTaskDelay () may not be fixed [the task may take a different path though the + * code between calls, or may get interrupted or preempted a different number of times + * each time it executes]. + * + * Whereas vTaskDelay () specifies a wake time relative to the time at which the function + * is called, vTaskDelayUntil () specifies the absolute (exact) time at which it wishes to + * unblock. + * + * The constant portTICK_RATE_MS can be used to calculate real time from the tick + * rate - with the resolution of one tick period. + * + * @param pxPreviousWakeTime Pointer to a variable that holds the time at which the + * task was last unblocked. The variable must be initialised with the current time + * prior to its first use (see the example below). Following this the variable is + * automatically updated within vTaskDelayUntil (). + * + * @param xTimeIncrement The cycle time period. The task will be unblocked at + * time *pxPreviousWakeTime + xTimeIncrement. Calling vTaskDelayUntil with the + * same xTimeIncrement parameter value will cause the task to execute with + * a fixed interface period. + * + * Example usage: + <pre> + // Perform an action every 10 ticks. + void vTaskFunction( void * pvParameters ) + { + portTickType xLastWakeTime; + const portTickType xFrequency = 10; + + // Initialise the xLastWakeTime variable with the current time. + xLastWakeTime = xTaskGetTickCount (); + for( ;; ) + { + // Wait for the next cycle. + vTaskDelayUntil( &xLastWakeTime, xFrequency ); + + // Perform action here. + } + } + </pre> + * \defgroup vTaskDelayUntil vTaskDelayUntil + * \ingroup TaskCtrl + */ +void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask );</pre> + * + * INCLUDE_xTaskPriorityGet must be defined as 1 for this function to be available. + * See the configuration section for more information. + * + * Obtain the priority of any task. + * + * @param pxTask Handle of the task to be queried. Passing a NULL + * handle results in the priority of the calling task being returned. + * + * @return The priority of pxTask. + * + * Example usage: + <pre> + void vAFunction( void ) + { + xTaskHandle xHandle; + + // Create a task, storing the handle. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle ); + + // ... + + // Use the handle to obtain the priority of the created task. + // It was created with tskIDLE_PRIORITY, but may have changed + // it itself. + if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY ) + { + // The task has changed it's priority. + } + + // ... + + // Is our priority higher than the created task? + if( uxTaskPriorityGet( xHandle ) < uxTaskPriorityGet( NULL ) ) + { + // Our priority (obtained using NULL handle) is higher. + } + } + </pre> + * \defgroup uxTaskPriorityGet uxTaskPriorityGet + * \ingroup TaskCtrl + */ +unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority );</pre> + * + * INCLUDE_vTaskPrioritySet must be defined as 1 for this function to be available. + * See the configuration section for more information. + * + * Set the priority of any task. + * + * A context switch will occur before the function returns if the priority + * being set is higher than the currently executing task. + * + * @param pxTask Handle to the task for which the priority is being set. + * Passing a NULL handle results in the priority of the calling task being set. + * + * @param uxNewPriority The priority to which the task will be set. + * + * Example usage: + <pre> + void vAFunction( void ) + { + xTaskHandle xHandle; + + // Create a task, storing the handle. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle ); + + // ... + + // Use the handle to raise the priority of the created task. + vTaskPrioritySet( xHandle, tskIDLE_PRIORITY + 1 ); + + // ... + + // Use a NULL handle to raise our priority to the same value. + vTaskPrioritySet( NULL, tskIDLE_PRIORITY + 1 ); + } + </pre> + * \defgroup vTaskPrioritySet vTaskPrioritySet + * \ingroup TaskCtrl + */ +void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void vTaskSuspend( xTaskHandle pxTaskToSuspend );</pre> + * + * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available. + * See the configuration section for more information. + * + * Suspend any task. When suspended a task will never get any microcontroller + * processing time, no matter what its priority. + * + * Calls to vTaskSuspend are not accumulative - + * i.e. calling vTaskSuspend () twice on the same task still only requires one + * call to vTaskResume () to ready the suspended task. + * + * @param pxTaskToSuspend Handle to the task being suspended. Passing a NULL + * handle will cause the calling task to be suspended. + * + * Example usage: + <pre> + void vAFunction( void ) + { + xTaskHandle xHandle; + + // Create a task, storing the handle. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle ); + + // ... + + // Use the handle to suspend the created task. + vTaskSuspend( xHandle ); + + // ... + + // The created task will not run during this period, unless + // another task calls vTaskResume( xHandle ). + + //... + + + // Suspend ourselves. + vTaskSuspend( NULL ); + + // We cannot get here unless another task calls vTaskResume + // with our handle as the parameter. + } + </pre> + * \defgroup vTaskSuspend vTaskSuspend + * \ingroup TaskCtrl + */ +void vTaskSuspend( xTaskHandle pxTaskToSuspend ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void vTaskResume( xTaskHandle pxTaskToResume );</pre> + * + * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available. + * See the configuration section for more information. + * + * Resumes a suspended task. + * + * A task that has been suspended by one of more calls to vTaskSuspend () + * will be made available for running again by a single call to + * vTaskResume (). + * + * @param pxTaskToResume Handle to the task being readied. + * + * Example usage: + <pre> + void vAFunction( void ) + { + xTaskHandle xHandle; + + // Create a task, storing the handle. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle ); + + // ... + + // Use the handle to suspend the created task. + vTaskSuspend( xHandle ); + + // ... + + // The created task will not run during this period, unless + // another task calls vTaskResume( xHandle ). + + //... + + + // Resume the suspended task ourselves. + vTaskResume( xHandle ); + + // The created task will once again get microcontroller processing + // time in accordance with it priority within the system. + } + </pre> + * \defgroup vTaskResume vTaskResume + * \ingroup TaskCtrl + */ +void vTaskResume( xTaskHandle pxTaskToResume ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void xTaskResumeFromISR( xTaskHandle pxTaskToResume );</pre> + * + * INCLUDE_xTaskResumeFromISR must be defined as 1 for this function to be + * available. See the configuration section for more information. + * + * An implementation of vTaskResume() that can be called from within an ISR. + * + * A task that has been suspended by one of more calls to vTaskSuspend () + * will be made available for running again by a single call to + * xTaskResumeFromISR (). + * + * @param pxTaskToResume Handle to the task being readied. + * + * \defgroup vTaskResumeFromISR vTaskResumeFromISR + * \ingroup TaskCtrl + */ +portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume ) PRIVILEGED_FUNCTION; + +/*----------------------------------------------------------- + * SCHEDULER CONTROL + *----------------------------------------------------------*/ + +/** + * task. h + * <pre>void vTaskStartScheduler( void );</pre> + * + * Starts the real time kernel tick processing. After calling the kernel + * has control over which tasks are executed and when. This function + * does not return until an executing task calls vTaskEndScheduler (). + * + * At least one task should be created via a call to xTaskCreate () + * before calling vTaskStartScheduler (). The idle task is created + * automatically when the first application task is created. + * + * See the demo application file main.c for an example of creating + * tasks and starting the kernel. + * + * Example usage: + <pre> + void vAFunction( void ) + { + // Create at least one task before starting the kernel. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL ); + + // Start the real time kernel with preemption. + vTaskStartScheduler (); + + // Will not get here unless a task calls vTaskEndScheduler () + } + </pre> + * + * \defgroup vTaskStartScheduler vTaskStartScheduler + * \ingroup SchedulerControl + */ +void vTaskStartScheduler( void ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void vTaskEndScheduler( void );</pre> + * + * Stops the real time kernel tick. All created tasks will be automatically + * deleted and multitasking (either preemptive or cooperative) will + * stop. Execution then resumes from the point where vTaskStartScheduler () + * was called, as if vTaskStartScheduler () had just returned. + * + * See the demo application file main. c in the demo/PC directory for an + * example that uses vTaskEndScheduler (). + * + * vTaskEndScheduler () requires an exit function to be defined within the + * portable layer (see vPortEndScheduler () in port. c for the PC port). This + * performs hardware specific operations such as stopping the kernel tick. + * + * vTaskEndScheduler () will cause all of the resources allocated by the + * kernel to be freed - but will not free resources allocated by application + * tasks. + * + * Example usage: + <pre> + void vTaskCode( void * pvParameters ) + { + for( ;; ) + { + // Task code goes here. + + // At some point we want to end the real time kernel processing + // so call ... + vTaskEndScheduler (); + } + } + + void vAFunction( void ) + { + // Create at least one task before starting the kernel. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL ); + + // Start the real time kernel with preemption. + vTaskStartScheduler (); + + // Will only get here when the vTaskCode () task has called + // vTaskEndScheduler (). When we get here we are back to single task + // execution. + } + </pre> + * + * \defgroup vTaskEndScheduler vTaskEndScheduler + * \ingroup SchedulerControl + */ +void vTaskEndScheduler( void ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>void vTaskSuspendAll( void );</pre> + * + * Suspends all real time kernel activity while keeping interrupts (including the + * kernel tick) enabled. + * + * After calling vTaskSuspendAll () the calling task will continue to execute + * without risk of being swapped out until a call to xTaskResumeAll () has been + * made. + * + * API functions that have the potential to cause a context switch (for example, + * vTaskDelayUntil(), xQueueSend(), etc.) must not be called while the scheduler + * is suspended. + * + * Example usage: + <pre> + void vTask1( void * pvParameters ) + { + for( ;; ) + { + // Task code goes here. + + // ... + + // At some point the task wants to perform a long operation during + // which it does not want to get swapped out. It cannot use + // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the + // operation may cause interrupts to be missed - including the + // ticks. + + // Prevent the real time kernel swapping out the task. + vTaskSuspendAll (); + + // Perform the operation here. There is no need to use critical + // sections as we have all the microcontroller processing time. + // During this time interrupts will still operate and the kernel + // tick count will be maintained. + + // ... + + // The operation is complete. Restart the kernel. + xTaskResumeAll (); + } + } + </pre> + * \defgroup vTaskSuspendAll vTaskSuspendAll + * \ingroup SchedulerControl + */ +void vTaskSuspendAll( void ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>char xTaskResumeAll( void );</pre> + * + * Resumes real time kernel activity following a call to vTaskSuspendAll (). + * After a call to vTaskSuspendAll () the kernel will take control of which + * task is executing at any time. + * + * @return If resuming the scheduler caused a context switch then pdTRUE is + * returned, otherwise pdFALSE is returned. + * + * Example usage: + <pre> + void vTask1( void * pvParameters ) + { + for( ;; ) + { + // Task code goes here. + + // ... + + // At some point the task wants to perform a long operation during + // which it does not want to get swapped out. It cannot use + // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the + // operation may cause interrupts to be missed - including the + // ticks. + + // Prevent the real time kernel swapping out the task. + vTaskSuspendAll (); + + // Perform the operation here. There is no need to use critical + // sections as we have all the microcontroller processing time. + // During this time interrupts will still operate and the real + // time kernel tick count will be maintained. + + // ... + + // The operation is complete. Restart the kernel. We want to force + // a context switch - but there is no point if resuming the scheduler + // caused a context switch already. + if( !xTaskResumeAll () ) + { + taskYIELD (); + } + } + } + </pre> + * \defgroup xTaskResumeAll xTaskResumeAll + * \ingroup SchedulerControl + */ +signed portBASE_TYPE xTaskResumeAll( void ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <pre>signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask );</pre> + * + * Utility task that simply returns pdTRUE if the task referenced by xTask is + * currently in the Suspended state, or pdFALSE if the task referenced by xTask + * is in any other state. + * + */ +signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask ) PRIVILEGED_FUNCTION; + +/*----------------------------------------------------------- + * TASK UTILITIES + *----------------------------------------------------------*/ + +/** + * task. h + * <PRE>portTickType xTaskGetTickCount( void );</PRE> + * + * @return The count of ticks since vTaskStartScheduler was called. + * + * \page xTaskGetTickCount xTaskGetTickCount + * \ingroup TaskUtils + */ +portTickType xTaskGetTickCount( void ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <PRE>portTickType xTaskGetTickCountFromISR( void );</PRE> + * + * @return The count of ticks since vTaskStartScheduler was called. + * + * This is a version of xTaskGetTickCount() that is safe to be called from an + * ISR - provided that portTickType is the natural word size of the + * microcontroller being used or interrupt nesting is either not supported or + * not being used. + * + * \page xTaskGetTickCount xTaskGetTickCount + * \ingroup TaskUtils + */ +portTickType xTaskGetTickCountFromISR( void ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <PRE>unsigned short uxTaskGetNumberOfTasks( void );</PRE> + * + * @return The number of tasks that the real time kernel is currently managing. + * This includes all ready, blocked and suspended tasks. A task that + * has been deleted but not yet freed by the idle task will also be + * included in the count. + * + * \page uxTaskGetNumberOfTasks uxTaskGetNumberOfTasks + * \ingroup TaskUtils + */ +unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <PRE>void vTaskList( char *pcWriteBuffer );</PRE> + * + * configUSE_TRACE_FACILITY must be defined as 1 for this function to be + * available. See the configuration section for more information. + * + * NOTE: This function will disable interrupts for its duration. It is + * not intended for normal application runtime use but as a debug aid. + * + * Lists all the current tasks, along with their current state and stack + * usage high water mark. + * + * Tasks are reported as blocked ('B'), ready ('R'), deleted ('D') or + * suspended ('S'). + * + * @param pcWriteBuffer A buffer into which the above mentioned details + * will be written, in ascii form. This buffer is assumed to be large + * enough to contain the generated report. Approximately 40 bytes per + * task should be sufficient. + * + * \page vTaskList vTaskList + * \ingroup TaskUtils + */ +void vTaskList( signed char *pcWriteBuffer ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <PRE>void vTaskGetRunTimeStats( char *pcWriteBuffer );</PRE> + * + * configGENERATE_RUN_TIME_STATS must be defined as 1 for this function + * to be available. The application must also then provide definitions + * for portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and + * portGET_RUN_TIME_COUNTER_VALUE to configure a peripheral timer/counter + * and return the timers current count value respectively. The counter + * should be at least 10 times the frequency of the tick count. + * + * NOTE: This function will disable interrupts for its duration. It is + * not intended for normal application runtime use but as a debug aid. + * + * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total + * accumulated execution time being stored for each task. The resolution + * of the accumulated time value depends on the frequency of the timer + * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro. + * Calling vTaskGetRunTimeStats() writes the total execution time of each + * task into a buffer, both as an absolute count value and as a percentage + * of the total system execution time. + * + * @param pcWriteBuffer A buffer into which the execution times will be + * written, in ascii form. This buffer is assumed to be large enough to + * contain the generated report. Approximately 40 bytes per task should + * be sufficient. + * + * \page vTaskGetRunTimeStats vTaskGetRunTimeStats + * \ingroup TaskUtils + */ +void vTaskGetRunTimeStats( signed char *pcWriteBuffer ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <PRE>void vTaskStartTrace( char * pcBuffer, unsigned portBASE_TYPE uxBufferSize );</PRE> + * + * Starts a real time kernel activity trace. The trace logs the identity of + * which task is running when. + * + * The trace file is stored in binary format. A separate DOS utility called + * convtrce.exe is used to convert this into a tab delimited text file which + * can be viewed and plotted in a spread sheet. + * + * @param pcBuffer The buffer into which the trace will be written. + * + * @param ulBufferSize The size of pcBuffer in bytes. The trace will continue + * until either the buffer in full, or ulTaskEndTrace () is called. + * + * \page vTaskStartTrace vTaskStartTrace + * \ingroup TaskUtils + */ +void vTaskStartTrace( signed char * pcBuffer, unsigned long ulBufferSize ) PRIVILEGED_FUNCTION; + +/** + * task. h + * <PRE>unsigned long ulTaskEndTrace( void );</PRE> + * + * Stops a kernel activity trace. See vTaskStartTrace (). + * + * @return The number of bytes that have been written into the trace buffer. + * + * \page usTaskEndTrace usTaskEndTrace + * \ingroup TaskUtils + */ +unsigned long ulTaskEndTrace( void ) PRIVILEGED_FUNCTION; + +/** + * task.h + * <PRE>unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask );</PRE> + * + * INCLUDE_uxTaskGetStackHighWaterMark must be set to 1 in FreeRTOSConfig.h for + * this function to be available. + * + * Returns the high water mark of the stack associated with xTask. That is, + * the minimum free stack space there has been (in words, so on a 32 bit machine + * a value of 1 means 4 bytes) since the task started. The smaller the returned + * number the closer the task has come to overflowing its stack. + * + * @param xTask Handle of the task associated with the stack to be checked. + * Set xTask to NULL to check the stack of the calling task. + * + * @return The smallest amount of free stack space there has been (in bytes) + * since the task referenced by xTask was created. + */ +unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask ) PRIVILEGED_FUNCTION; + +/* When using trace macros it is sometimes necessary to include tasks.h before +FreeRTOS.h. When this is done pdTASK_HOOK_CODE will not yet have been defined, +so the following two prototypes will cause a compilation error. This can be +fixed by simply guarding against the inclusion of these two prototypes unless +they are explicitly required by the configUSE_APPLICATION_TASK_TAG configuration +constant. */ +#ifdef configUSE_APPLICATION_TASK_TAG + #if configUSE_APPLICATION_TASK_TAG == 1 + /** + * task.h + * <pre>void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxHookFunction );</pre> + * + * Sets pxHookFunction to be the task hook function used by the task xTask. + * Passing xTask as NULL has the effect of setting the calling tasks hook + * function. + */ + void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxHookFunction ) PRIVILEGED_FUNCTION; + + /** + * task.h + * <pre>void xTaskGetApplicationTaskTag( xTaskHandle xTask );</pre> + * + * Returns the pxHookFunction value assigned to the task xTask. + */ + pdTASK_HOOK_CODE xTaskGetApplicationTaskTag( xTaskHandle xTask ) PRIVILEGED_FUNCTION; + #endif /* configUSE_APPLICATION_TASK_TAG ==1 */ +#endif /* ifdef configUSE_APPLICATION_TASK_TAG */ + +/** + * task.h + * <pre>portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, pdTASK_HOOK_CODE pxHookFunction );</pre> + * + * Calls the hook function associated with xTask. Passing xTask as NULL has + * the effect of calling the Running tasks (the calling task) hook function. + * + * pvParameter is passed to the hook function for the task to interpret as it + * wants. + */ +portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, void *pvParameter ) PRIVILEGED_FUNCTION; + + +/*----------------------------------------------------------- + * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES + *----------------------------------------------------------*/ + +/* + * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY + * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS + * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER. + * + * Called from the real time kernel tick (either preemptive or cooperative), + * this increments the tick count and checks if any tasks that are blocked + * for a finite period required removing from a blocked list and placing on + * a ready list. + */ +void vTaskIncrementTick( void ) PRIVILEGED_FUNCTION; + +/* + * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN + * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER. + * + * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED. + * + * Removes the calling task from the ready list and places it both + * on the list of tasks waiting for a particular event, and the + * list of delayed tasks. The task will be removed from both lists + * and replaced on the ready list should either the event occur (and + * there be no higher priority tasks waiting on the same event) or + * the delay period expires. + * + * @param pxEventList The list containing tasks that are blocked waiting + * for the event to occur. + * + * @param xTicksToWait The maximum amount of time that the task should wait + * for the event to occur. This is specified in kernel ticks,the constant + * portTICK_RATE_MS can be used to convert kernel ticks into a real time + * period. + */ +void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait ) PRIVILEGED_FUNCTION; + +/* + * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN + * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER. + * + * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED. + * + * This function performs nearly the same function as vTaskPlaceOnEventList(). + * The difference being that this function does not permit tasks to block + * indefinitely, whereas vTaskPlaceOnEventList() does. + * + * @return pdTRUE if the task being removed has a higher priority than the task + * making the call, otherwise pdFALSE. + */ +void vTaskPlaceOnEventListRestricted( const xList * const pxEventList, portTickType xTicksToWait ) PRIVILEGED_FUNCTION; + +/* + * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN + * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER. + * + * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED. + * + * Removes a task from both the specified event list and the list of blocked + * tasks, and places it on a ready queue. + * + * xTaskRemoveFromEventList () will be called if either an event occurs to + * unblock a task, or the block timeout period expires. + * + * @return pdTRUE if the task being removed has a higher priority than the task + * making the call, otherwise pdFALSE. + */ +signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList ) PRIVILEGED_FUNCTION; + +/* + * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN + * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER. + * + * INCLUDE_vTaskCleanUpResources and INCLUDE_vTaskSuspend must be defined as 1 + * for this function to be available. + * See the configuration section for more information. + * + * Empties the ready and delayed queues of task control blocks, freeing the + * memory allocated for the task control block and task stacks as it goes. + */ +void vTaskCleanUpResources( void ) PRIVILEGED_FUNCTION; + +/* + * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY + * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS + * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER. + * + * Sets the pointer to the current TCB to the TCB of the highest priority task + * that is ready to run. + */ +void vTaskSwitchContext( void ) PRIVILEGED_FUNCTION; + +/* + * Return the handle of the calling task. + */ +xTaskHandle xTaskGetCurrentTaskHandle( void ) PRIVILEGED_FUNCTION; + +/* + * Capture the current time status for future reference. + */ +void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut ) PRIVILEGED_FUNCTION; + +/* + * Compare the time status now with that previously captured to see if the + * timeout has expired. + */ +portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait ) PRIVILEGED_FUNCTION; + +/* + * Shortcut used by the queue implementation to prevent unnecessary call to + * taskYIELD(); + */ +void vTaskMissedYield( void ) PRIVILEGED_FUNCTION; + +/* + * Returns the scheduler state as taskSCHEDULER_RUNNING, + * taskSCHEDULER_NOT_STARTED or taskSCHEDULER_SUSPENDED. + */ +portBASE_TYPE xTaskGetSchedulerState( void ) PRIVILEGED_FUNCTION; + +/* + * Raises the priority of the mutex holder to that of the calling task should + * the mutex holder have a priority less than the calling task. + */ +void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder ) PRIVILEGED_FUNCTION; + +/* + * Set the priority of a task back to its proper priority in the case that it + * inherited a higher priority while it was holding a semaphore. + */ +void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder ) PRIVILEGED_FUNCTION; + +/* + * Generic version of the task creation function which is in turn called by the + * xTaskCreate() and xTaskCreateRestricted() macros. + */ +signed portBASE_TYPE xTaskGenericCreate( pdTASK_CODE pxTaskCode, const signed char * const pcName, unsigned short usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask, portSTACK_TYPE *puxStackBuffer, const xMemoryRegion * const xRegions ) PRIVILEGED_FUNCTION; + +#ifdef __cplusplus +} +#endif +#endif /* TASK_H */ + + + |