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diff --git a/openpicc/os/core/include/task.h b/openpicc/os/core/include/task.h new file mode 100644 index 0000000..3d01c53 --- /dev/null +++ b/openpicc/os/core/include/task.h @@ -0,0 +1,960 @@ +/* + FreeRTOS.org V4.2.1 - Copyright (C) 2003-2007 Richard Barry. + + This file is part of the FreeRTOS.org distribution. + + FreeRTOS.org 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.org 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.org; 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.org, 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. + + Also see http://www.SafeRTOS.com for an IEC 61508 compliant version along + with commercial development and support options. + *************************************************************************** +*/ + +#ifndef TASK_H +#define TASK_H + +#include "portable.h" +#include "list.h" + +/*----------------------------------------------------------- + * MACROS AND DEFINITIONS + *----------------------------------------------------------*/ + +#define tskKERNEL_VERSION_NUMBER "V4.2.1" + +/** + * 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 priority used by the idle task. This must not be modified. + * + * \ingroup TaskUtils + */ +#define tskIDLE_PRIORITY ( ( unsigned portBASE_TYPE ) 0 ) + +/** + * 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() + + +/*----------------------------------------------------------- + * TASK CREATION API + *----------------------------------------------------------*/ + +/** + * task. h + *<pre> + portBASE_TYPE xTaskCreate( + pdTASK_CODE pvTaskCode, + const portCHAR * const pcName, + unsigned portSHORT 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. + * + * @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. + * + * @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 ) + { + unsigned char ucParameterToPass; + xTaskHandle xHandle; + + // Create the task, storing the handle. + xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle ); + + // Use the handle to delete the task. + vTaskDelete( xHandle ); + } + </pre> + * \defgroup xTaskCreate xTaskCreate + * \ingroup Tasks + */ +signed portBASE_TYPE xTaskCreate (pdTASK_CODE pvTaskCode, + const signed portCHAR * const pcName, + unsigned portSHORT usStackDepth, + void *pvParameters, + unsigned portBASE_TYPE uxPriority, + xTaskHandle * pvCreatedTask); + +/** + * 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 pxTask); + + +/*----------------------------------------------------------- + * 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. + * + * @param xTicksToDelay The amount of time, in tick periods, that + * the calling task should block. + * + * Example usage: + <pre> + // Wait 10 ticks before performing an action. + // NOTE: + // This is for demonstration only and would be better achieved + // using vTaskDelayUntil (). + void vTaskFunction( void * pvParameters ) + { + portTickType xDelay, xNextTime; + + // Calc the time at which we want to perform the action + // next. + xNextTime = xTaskGetTickCount () + ( portTickType ) 10; + + for( ;; ) + { + xDelay = xNextTime - xTaskGetTickCount (); + xNextTime += ( portTickType ) 10; + + // Guard against overflow + if( xDelay <= ( portTickType ) 10 ) + { + vTaskDelay( xDelay ); + } + + // Perform action here. + } + } + </pre> + * \defgroup vTaskDelay vTaskDelay + * \ingroup TaskCtrl + */ +void vTaskDelay (portTickType xTicksToDelay); + +/** + * 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 * pxPreviousWakeTime, + portTickType xTimeIncrement); + +/** + * 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); + +/** + * 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); + +/** + * 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); + +/** + * 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); + +/** + * 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); + +/*----------------------------------------------------------- + * 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); + +/** + * 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); + +/** + * 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. + * + * 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); + +/** + * task. h + * <pre>portCHAR 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); + + +/*----------------------------------------------------------- + * TASK UTILITIES + *----------------------------------------------------------*/ + +/** + * task. h + * <PRE>volatile portTickType xTaskGetTickCount( void );</PRE> + * + * @return The count of ticks since vTaskStartScheduler was called. + * + * \page xTaskGetTickCount xTaskGetTickCount + * \ingroup TaskUtils + */ +portTickType xTaskGetTickCount (void); + +/** + * task. h + * <PRE>unsigned portSHORT 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); + +/** + * task. h + * <PRE>void vTaskList( portCHAR *pcWriteBuffer );</PRE> + * + * configUSE_TRACE_FACILITY, INCLUDE_vTaskDelete and INCLUDE_vTaskSuspend + * must all 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 portCHAR * pcWriteBuffer); + +/** + * task. h + * <PRE>void vTaskStartTrace( portCHAR * 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 portCHAR * pcBuffer, + unsigned portLONG ulBufferSize); + +/** + * task. h + * <PRE>unsigned portLONG 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 portLONG ulTaskEndTrace (void); + + +/*----------------------------------------------------------- + * 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. + */ +inline void vTaskIncrementTick (void); + +/* + * 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 (xList * pxEventList, portTickType xTicksToWait); + +/* + * 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 * pxEventList); + +/* + * 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); + +/* + * 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. + */ +inline void vTaskSwitchContext (void); + +/* + * Return the handle of the calling task. + */ +xTaskHandle xTaskGetCurrentTaskHandle (void); + +/* + * Capture the current time status for future reference. + */ +void vTaskSetTimeOutState (xTimeOutType * pxTimeOut); + +/* + * Compare the time status now with that previously captured to see if the + * timeout has expired. + */ +portBASE_TYPE xTaskCheckForTimeOut (xTimeOutType * pxTimeOut, + portTickType * pxTicksToWait); + +/* + * Shortcut used by the queue implementation to prevent unnecessary call to + * taskYIELD(); + */ +void vTaskMissedYield (void); + +#endif /* TASK_H */ |