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TNeoKernel
v1.04
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TNeoKernel
v1.04
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Kernel system routines: system start, tick processing, time slice managing.
Definition in file tn_sys.h.
Go to the source code of this file.
Macros | |
| #define | TN_STACK_ARR_DEF(name, size) |
| Convenience macro for the definition of stack array. More... | |
| #define | TN_NO_TIME_SLICE 0 |
Value to pass to tn_sys_tslice_set() to turn round-robin off. | |
| #define | TN_MAX_TIME_SLICE 0xFFFE |
| Max value of time slice. | |
Typedefs | |
| typedef void( | TN_CBUserTaskCreate )(void) |
User-provided callback function that is called directly from tn_sys_start() as a part of system startup routine; it should merely create at least one (and typically just one) user's task, which should perform all the rest application initialization. More... | |
| typedef void( | TN_CBIdle )(void) |
| User-provided callback function that is called repeatedly from the idle task loop. More... | |
| typedef void( | TN_CBDeadlock )(TN_BOOL active, struct TN_Mutex *mutex, struct TN_Task *task) |
| User-provided callback function that is called whenever deadlock becomes active or inactive. More... | |
Enumerations | |
| enum | TN_StateFlag { TN_STATE_FLAG__SYS_RUNNING = (1 << 0), TN_STATE_FLAG__DEADLOCK = (1 << 1) } |
| System state flags. More... | |
| enum | TN_Context { TN_CONTEXT_NONE, TN_CONTEXT_TASK, TN_CONTEXT_ISR } |
| System context. More... | |
Functions | |
| void | tn_sys_start (TN_UWord *idle_task_stack, unsigned int idle_task_stack_size, TN_UWord *int_stack, unsigned int int_stack_size, TN_CBUserTaskCreate *cb_user_task_create, TN_CBIdle *cb_idle) |
| Initial TNeoKernel system start function, never returns. More... | |
| enum TN_RCode | tn_tick_int_processing (void) |
| Process system tick; should be called periodically, typically from some kind of timer ISR. More... | |
| enum TN_RCode | tn_sys_tslice_set (int priority, int ticks) |
| Set time slice ticks value for specified priority (see Round-robin scheduling). More... | |
| unsigned int | tn_sys_time_get (void) |
| Get current system ticks count. More... | |
| void | tn_callback_deadlock_set (TN_CBDeadlock *cb) |
| Set callback function that should be called whenever deadlock occurs or becomes inactive (say, if one of tasks involved in the deadlock was released from wait because of timeout) More... | |
| enum TN_StateFlag | tn_sys_state_flags_get (void) |
| Returns current system state flags. More... | |
| enum TN_Context | tn_sys_context_get (void) |
| Returns system context: task or ISR. More... | |
| static TN_BOOL | tn_is_task_context (void) |
Returns whether current system context is TN_CONTEXT_TASK More... | |
| static TN_BOOL | tn_is_isr_context (void) |
Returns whether current system context is TN_CONTEXT_ISR More... | |
| struct TN_Task * | tn_cur_task_get (void) |
| Returns pointer to the currently running task. More... | |
| TN_TaskBody * | tn_cur_task_body_get (void) |
| Returns pointer to the body function of the currently running task. More... | |
| #define TN_STACK_ARR_DEF | ( | name, | |
| size | |||
| ) |
Convenience macro for the definition of stack array.
See tn_task_create() for the usage example.
| name | C variable name of the array |
| size | size of the stack array in words (TN_UWord), not in bytes. |
| typedef void( TN_CBUserTaskCreate)(void) |
User-provided callback function that is called directly from tn_sys_start() as a part of system startup routine; it should merely create at least one (and typically just one) user's task, which should perform all the rest application initialization.
When TN_CBUserTaskCreate() returned, the kernel performs first context switch to the task with highest priority. If there are several tasks with highest priority, context is switched to the first created one.
Refer to the section Starting the kernel for details about system startup process on the whole.
Note: Although you're able to create more than one task here, it's usually not so good idea, because many things typically should be done at startup before tasks can go on with their job: we need to initialize various on-board peripherals (displays, flash memory chips, or whatever) as well as initialize software modules used by application. So, if many tasks are created here, you have to provide some synchronization object so that tasks will wait until all the initialization is done.
It's usually easier to maintain if we create just one task here, which firstly performs all the necessary initialization, then creates the rest of your tasks, and eventually gets to its primary job (the job for which task was created at all). For the usage example, refer to the page Starting the kernel.
tn_task_create().tn_sys_start() | typedef void( TN_CBIdle)(void) |
User-provided callback function that is called repeatedly from the idle task loop.
Make sure that idle task has enough stack space to call this function.
TN_DEBUG option is set, then sleeping in idle task is checked, so if you try to sleep here, _TN_FATAL_ERROR() macro will be called.tn_sys_start() User-provided callback function that is called whenever deadlock becomes active or inactive.
Note: this feature works if only TN_MUTEX_DEADLOCK_DETECT is non-zero.
| active | Boolean value indicating whether deadlock becomes active or inactive. Note: deadlock might become inactive if, for example, one of tasks involved in deadlock exits from waiting by timeout. |
| mutex | mutex that is involved in deadlock. You may find out other mutexes involved by means of mutex->deadlock_list. |
| task | task that is involved in deadlock. You may find out other tasks involved by means of task->deadlock_list. |
| enum TN_StateFlag |
System state flags.
| Enumerator | |
|---|---|
| TN_STATE_FLAG__SYS_RUNNING |
system is running |
| TN_STATE_FLAG__DEADLOCK |
deadlock is active Note: this feature works if only
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| enum TN_Context |
System context.
tn_sys_context_get() | Enumerator | |
|---|---|
| TN_CONTEXT_NONE |
None: this code is possible if only system is not running (flag ( |
| TN_CONTEXT_TASK |
Task context. |
| TN_CONTEXT_ISR |
ISR context. |
| void tn_sys_start | ( | TN_UWord * | idle_task_stack, |
| unsigned int | idle_task_stack_size, | ||
| TN_UWord * | int_stack, | ||
| unsigned int | int_stack_size, | ||
| TN_CBUserTaskCreate * | cb_user_task_create, | ||
| TN_CBIdle * | cb_idle | ||
| ) |
Initial TNeoKernel system start function, never returns.
Typically called from main().
Refer to the Starting the kernel section for the usage example and additional comments.
(refer to Legend for details)
| idle_task_stack | Pointer to array for idle task stack. User must either use the macro TN_STACK_ARR_DEF() for the definition of stack array, or allocate it manually as an array of TN_UWord with TN_ARCH_STK_ATTR_BEFORE and TN_ARCH_STK_ATTR_AFTER macros. |
| idle_task_stack_size | Size of idle task stack, in words (TN_UWord) |
| int_stack | Pointer to array for interrupt stack. User must either use the macro TN_STACK_ARR_DEF() for the definition of stack array, or allocate it manually as an array of TN_UWord with TN_ARCH_STK_ATTR_BEFORE and TN_ARCH_STK_ATTR_AFTER macros. |
| int_stack_size | Size of interrupt stack, in words (TN_UWord) |
| cb_user_task_create | Callback function that should create initial user's task, see TN_CBUserTaskCreate for details. |
| cb_idle | Callback function repeatedly called from idle task, see TN_CBIdle for details. |
| enum TN_RCode tn_tick_int_processing | ( | void | ) |
Process system tick; should be called periodically, typically from some kind of timer ISR.
The period of this timer is determined by user (typically 1 ms, but user is free to set different value)
Among other things, expired timers are fired from this function.
For further information, refer to Quick guide.
TN_RC_OK on success;TN_RC_WCONTEXT if called from wrong context. | enum TN_RCode tn_sys_tslice_set | ( | int | priority, |
| int | ticks | ||
| ) |
Set time slice ticks value for specified priority (see Round-robin scheduling).
| priority | Priority of tasks for which time slice value should be set |
| ticks | Time slice value, in ticks. Set to TN_NO_TIME_SLICE for no round-robin scheduling for given priority (it's default value). Value can't be higher than TN_MAX_TIME_SLICE. |
TN_RC_OK on success;TN_RC_WCONTEXT if called from wrong context;TN_RC_WPARAM if given priority or ticks are invalid. | unsigned int tn_sys_time_get | ( | void | ) |
| void tn_callback_deadlock_set | ( | TN_CBDeadlock * | cb | ) |
Set callback function that should be called whenever deadlock occurs or becomes inactive (say, if one of tasks involved in the deadlock was released from wait because of timeout)
(refer to Legend for details)
Note: this function should be called from main(), before tn_sys_start().
| cb | Pointer to user-provided callback function. |
TN_MUTEX_DEADLOCK_DETECT TN_CBDeadlock for callback function prototype | enum TN_StateFlag tn_sys_state_flags_get | ( | void | ) |
| enum TN_Context tn_sys_context_get | ( | void | ) |
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inlinestatic |
Returns whether current system context is TN_CONTEXT_TASK
TN_TRUE if current system context is TN_CONTEXT_TASK, TN_FALSE otherwise.tn_sys_context_get() enum TN_Context
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inlinestatic |
Returns whether current system context is TN_CONTEXT_ISR
TN_TRUE if current system context is TN_CONTEXT_ISR, TN_FALSE otherwise.tn_sys_context_get() enum TN_Context | struct TN_Task* tn_cur_task_get | ( | void | ) |
| TN_TaskBody* tn_cur_task_body_get | ( | void | ) |
1.8.8